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* [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
@ 2018-05-31 11:06 Gao Xiang
  2018-06-01  7:48 ` Richard Weinberger
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
  0 siblings, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-05-31 11:06 UTC (permalink / raw)
  To: linux-kernel, linux-fsdevel
  Cc: miaoxie, yuchao0, sunqiuyang, fangwei1, liguifu2, weidu.du,
	chen.chun.yen, brooke.wangzhigang, dongjinguang, gaoxiang25

Hi all,

Read-only file systems are used in many cases, such as read-only storage media.
We are now focusing on the Android device which several read-only partitions exist.
Due to limited read-only solutions, a new read-only file system EROFS
(Extendable Read-Only File System) is introduced.

As the other read-only file systems, several meta regions in generic file systems
such as free space bitmap are omitted. But the difference is that EROFS focuses
more on performance than purely on saving storage space as much as possible.

Furthermore, we also add the compression support called z_erofs.

Traditional file systems with the compression support use the fixed-sized input
compression, the output compressed units could be arbitrary lengths.
However, data is accessed in the block unit for block devices, which means
(A) if the accessed compressed data is not buffered, some data read from
the physical block cannot be further utilized, which is illustrated as follows:
       
   ++-----------++-----------++         ++-----------++-----------++
...||           ||           ||   ...   ||           ||           ||  ... original data
   ++-----------++-----------++         ++-----------++-----------++
    \                         /          \                         /
       \                   /                \                    /
          \             /                      \               /
      ++---|-------++--|--------++       ++-----|----++--------|--++
      ||xxx|       ||  |xxxxxxxx||  ...  ||xxxxx|    ||        |xx||  compressed data
      ++---|-------++--|--------++       ++-----|----++--------|--++

The shadow regions read from the block device but cannot be used for decompression.

(B) If the compressed data is also buffered, it will increase the memory overhead.
Because these are compressed data, it cannot be directly used, and we don't know
when the corresponding compressed blocks are accessed, which is not friendly to
the random read.

In order to reduce the proportion of the data which cannot be directly decompressed,
larger compressed sizes are preferred to be selected, which is also not friendly to
the random read.

Erofs implements the compression in a different approach, the details of which will
be discussed in the next section.

In brief, the following points summarize our design at a high level:

1) Use page-sized blocks so that there are no buffer heads.

2) By introducing a more general inline data / xattr, metadata and small data have
the opportunity to be read with the inode metadata at the same time.

3) Introduce another shared xattr region in order to store the common xattrs (eg.
selinux labels) or xattrs too large to be suitable for meta inline.

4) Metadata and data could be mixed by design, so it could be more flexible for mkfs
to organize files and data.

5) instead of using the fixed-sized input compression, we put forward a new fixed
output compression to make the full use of IO (which means all data from IO can be
decompressed), reduce the read amplification, improve random read and keep the
relatively lower compression ratios, illustrated as follows:


        |---- varient-length extent ----|------ VLE ------|---  VLE ---|
         /> clusterofs                  /> clusterofs     /> clusterofs /> clusterofs
   ++---|-------++-----------++---------|-++-----------++-|---------++-|
...||   |       ||           ||         | ||           || |         || | ... original data
   ++---|-------++-----------++---------|-++-----------++-|---------++-|
   ++->cluster<-++->cluster<-++->cluster<-++->cluster<-++->cluster<-++
        size         size         size         size         size  
         \                             /                 /            /
          \                      /              /            /
           \               /            /            /
            ++-----------++-----------++-----------++
        ... ||           ||           ||           || ... compressed clusters
            ++-----------++-----------++-----------++
            ++->cluster<-++->cluster<-++->cluster<-++
                 size         size         size

   A cluster could have more than one blocks by design, but currently we only have the
page-sized cluster implementation (page-sized fixed output compression can also have
better compression ratio than fixed input compression).

   All compressed clusters have a fixed size but could be decompressed into extents with
arbitrary lengths.

   In addition, if a buffered IO reads the following shadow region (x), we could make a more
   customized path (to replace generic_file_buffered_read) which only reads one compressed
   cluster and makes the partial page available.
         /> clusterofs
   ++---|-------++
...||   | xxxx  || ...
   ||---|-------||

Some numbers using fixed output compression (VLE, cluster size = block size = 4k) on
the server and Android phone (kirin970 platform):

Server (magnetic disk):

compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)

  4              480.3          502.5                   69.8               11.1
 10              472.3          503.3                   56.4               10.0
 15              457.6          495.3                   47.0               10.9
 26              401.5          511.2                   34.7               11.1
 35              389.1          512.5                   28.0               11.0
 48              375.4          496.5                   23.2               10.6
 53              370.2          512.0                   21.8               11.0
 66              349.2          512.0                   19.0               11.4
 76              310.5          497.3                   17.3               11.6
 85              301.2          512.0                   16.0               11.0
 94              292.7          496.5                   14.6               11.1
100              538.9          512.0                   11.4               10.8

Kirin970 (A73 Big-core 2361Mhz, A53 little-core 0Mhz, DDR 1866Mhz):

compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)

  4              546.7          544.3                    157.7              57.9
 10              535.7          521.0                    152.7              62.0
 15              529.0          520.3                    125.0              65.0
 26              418.0          526.3                     97.6              63.7
 35              367.7          511.7                     89.0              63.7
 48              415.7          500.7                     78.2              61.2
 53              423.0          566.7                     72.8              62.9
 66              334.3          537.3                     69.8              58.3
 76              387.3          546.0                     65.2              56.0
 85              306.3          546.0                     63.8              57.7
 94              345.0          589.7                     59.2              49.9
100              579.7          556.7                     62.1              57.7

* currently we use workqueue for the read-ahead process, which is still has some
minor issues and the value of sequential read is effected by work queue scheduling.



This patchset is only for opensource archive use, the file system still has issues
and will be work in progress in the coming few months.


We will make a developing tree and an independent mailing list in a few days.



Any comments are welcome :-)



Recently TODO list:
1) Add a documentation on the on-disk layout and kernel file system design;

2) Remove all Linux kernel version macros and devide it into separated kernel version tree;

3) the open source of erofs-mkfs is _still_ in progress, it will be released as soon as
   the internal process ends.
   
4) VLE decompression code still needs to do more optimization and cleanup.


Thanks,


Gao Xiang (12):
  erofs: add on-disk layout
  erofs: add erofs in-memory stuffs
  erofs: add super block operations
  erofs: add raw address_space operations
  erofs: add inode operations
  erofs: add directory operations
  erofs: add namei functions
  erofs: definitions for the various kernel version temporarily
  erofs: update Kconfig and Makefile
  erofs: introduce xattr & acl support
  erofs: introduce a customized LZ4 decompression
  erofs: introduce VLE decompression support (experimental)

 fs/Kconfig               |    1 +
 fs/Makefile              |    1 +
 fs/erofs/Kconfig         |   88 ++++
 fs/erofs/Makefile        |    9 +
 fs/erofs/data.c          |  569 +++++++++++++++++++++++++
 fs/erofs/dir.c           |  143 +++++++
 fs/erofs/erofs_fs.h      |  258 ++++++++++++
 fs/erofs/inode.c         |  287 +++++++++++++
 fs/erofs/internal.h      |  413 ++++++++++++++++++
 fs/erofs/lz4defs.h       |  227 ++++++++++
 fs/erofs/namei.c         |  250 +++++++++++
 fs/erofs/pagevec.h       |  184 ++++++++
 fs/erofs/staging.h       |   83 ++++
 fs/erofs/super.c         |  422 +++++++++++++++++++
 fs/erofs/unzip.c         | 1039 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/erofs/unzip.h         |  119 ++++++
 fs/erofs/unzip_generic.c |  295 +++++++++++++
 fs/erofs/unzip_lz4.c     |  221 ++++++++++
 fs/erofs/unzip_vle.h     |   79 ++++
 fs/erofs/xattr.c         |  678 ++++++++++++++++++++++++++++++
 fs/erofs/xattr.h         |   93 +++++
 21 files changed, 5459 insertions(+)
 create mode 100644 fs/erofs/Kconfig
 create mode 100644 fs/erofs/Makefile
 create mode 100644 fs/erofs/data.c
 create mode 100644 fs/erofs/dir.c
 create mode 100644 fs/erofs/erofs_fs.h
 create mode 100644 fs/erofs/inode.c
 create mode 100644 fs/erofs/internal.h
 create mode 100644 fs/erofs/lz4defs.h
 create mode 100644 fs/erofs/namei.c
 create mode 100644 fs/erofs/pagevec.h
 create mode 100644 fs/erofs/staging.h
 create mode 100644 fs/erofs/super.c
 create mode 100644 fs/erofs/unzip.c
 create mode 100644 fs/erofs/unzip.h
 create mode 100644 fs/erofs/unzip_generic.c
 create mode 100644 fs/erofs/unzip_lz4.c
 create mode 100644 fs/erofs/unzip_vle.h
 create mode 100644 fs/erofs/xattr.c
 create mode 100644 fs/erofs/xattr.h

-- 
1.9.1

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-05-31 11:06 [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system Gao Xiang
@ 2018-06-01  7:48 ` Richard Weinberger
  2018-06-01  9:11   ` Gao Xiang
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
  1 sibling, 1 reply; 58+ messages in thread
From: Richard Weinberger @ 2018-06-01  7:48 UTC (permalink / raw)
  To: Gao Xiang
  Cc: LKML, linux-fsdevel, miaoxie, yuchao0, sunqiuyang, fangwei1,
	liguifu2, weidu.du, chen.chun.yen, brooke.wangzhigang,
	dongjinguang

On Thu, May 31, 2018 at 1:06 PM, Gao Xiang <gaoxiang25@huawei.com> wrote:
> Hi all,
>
> Read-only file systems are used in many cases, such as read-only storage media.
> We are now focusing on the Android device which several read-only partitions exist.
> Due to limited read-only solutions, a new read-only file system EROFS
> (Extendable Read-Only File System) is introduced.

In which sense is it extendable?

> As the other read-only file systems, several meta regions in generic file systems
> such as free space bitmap are omitted. But the difference is that EROFS focuses
> more on performance than purely on saving storage space as much as possible.
>
> Furthermore, we also add the compression support called z_erofs.
>
> Traditional file systems with the compression support use the fixed-sized input
> compression, the output compressed units could be arbitrary lengths.
> However, data is accessed in the block unit for block devices, which means
> (A) if the accessed compressed data is not buffered, some data read from
> the physical block cannot be further utilized, which is illustrated as follows:
>
>    ++-----------++-----------++         ++-----------++-----------++
> ...||           ||           ||   ...   ||           ||           ||  ... original data
>    ++-----------++-----------++         ++-----------++-----------++
>     \                         /          \                         /
>        \                   /                \                    /
>           \             /                      \               /
>       ++---|-------++--|--------++       ++-----|----++--------|--++
>       ||xxx|       ||  |xxxxxxxx||  ...  ||xxxxx|    ||        |xx||  compressed data
>       ++---|-------++--|--------++       ++-----|----++--------|--++
>
> The shadow regions read from the block device but cannot be used for decompression.
>
> (B) If the compressed data is also buffered, it will increase the memory overhead.
> Because these are compressed data, it cannot be directly used, and we don't know
> when the corresponding compressed blocks are accessed, which is not friendly to
> the random read.
>
> In order to reduce the proportion of the data which cannot be directly decompressed,
> larger compressed sizes are preferred to be selected, which is also not friendly to
> the random read.
>
> Erofs implements the compression in a different approach, the details of which will
> be discussed in the next section.
>
> In brief, the following points summarize our design at a high level:
>
> 1) Use page-sized blocks so that there are no buffer heads.
>
> 2) By introducing a more general inline data / xattr, metadata and small data have
> the opportunity to be read with the inode metadata at the same time.
>
> 3) Introduce another shared xattr region in order to store the common xattrs (eg.
> selinux labels) or xattrs too large to be suitable for meta inline.
>
> 4) Metadata and data could be mixed by design, so it could be more flexible for mkfs
> to organize files and data.
>
> 5) instead of using the fixed-sized input compression, we put forward a new fixed
> output compression to make the full use of IO (which means all data from IO can be
> decompressed), reduce the read amplification, improve random read and keep the
> relatively lower compression ratios, illustrated as follows:
>
>
>         |---- varient-length extent ----|------ VLE ------|---  VLE ---|
>          /> clusterofs                  /> clusterofs     /> clusterofs /> clusterofs
>    ++---|-------++-----------++---------|-++-----------++-|---------++-|
> ...||   |       ||           ||         | ||           || |         || | ... original data
>    ++---|-------++-----------++---------|-++-----------++-|---------++-|
>    ++->cluster<-++->cluster<-++->cluster<-++->cluster<-++->cluster<-++
>         size         size         size         size         size
>          \                             /                 /            /
>           \                      /              /            /
>            \               /            /            /
>             ++-----------++-----------++-----------++
>         ... ||           ||           ||           || ... compressed clusters
>             ++-----------++-----------++-----------++
>             ++->cluster<-++->cluster<-++->cluster<-++
>                  size         size         size
>
>    A cluster could have more than one blocks by design, but currently we only have the
> page-sized cluster implementation (page-sized fixed output compression can also have
> better compression ratio than fixed input compression).
>
>    All compressed clusters have a fixed size but could be decompressed into extents with
> arbitrary lengths.
>
>    In addition, if a buffered IO reads the following shadow region (x), we could make a more
>    customized path (to replace generic_file_buffered_read) which only reads one compressed
>    cluster and makes the partial page available.
>          /> clusterofs
>    ++---|-------++
> ...||   | xxxx  || ...
>    ||---|-------||
>
> Some numbers using fixed output compression (VLE, cluster size = block size = 4k) on
> the server and Android phone (kirin970 platform):
>
> Server (magnetic disk):
>
> compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
> ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)
>
>   4              480.3          502.5                   69.8               11.1
>  10              472.3          503.3                   56.4               10.0
>  15              457.6          495.3                   47.0               10.9
>  26              401.5          511.2                   34.7               11.1
>  35              389.1          512.5                   28.0               11.0
>  48              375.4          496.5                   23.2               10.6
>  53              370.2          512.0                   21.8               11.0
>  66              349.2          512.0                   19.0               11.4
>  76              310.5          497.3                   17.3               11.6
>  85              301.2          512.0                   16.0               11.0
>  94              292.7          496.5                   14.6               11.1
> 100              538.9          512.0                   11.4               10.8
>
> Kirin970 (A73 Big-core 2361Mhz, A53 little-core 0Mhz, DDR 1866Mhz):

What storage was used? An eMMC?

> compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
> ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)
>
>   4              546.7          544.3                    157.7              57.9
>  10              535.7          521.0                    152.7              62.0
>  15              529.0          520.3                    125.0              65.0
>  26              418.0          526.3                     97.6              63.7
>  35              367.7          511.7                     89.0              63.7
>  48              415.7          500.7                     78.2              61.2
>  53              423.0          566.7                     72.8              62.9
>  66              334.3          537.3                     69.8              58.3
>  76              387.3          546.0                     65.2              56.0
>  85              306.3          546.0                     63.8              57.7
>  94              345.0          589.7                     59.2              49.9
> 100              579.7          556.7                     62.1              57.7

How does it compare to existing read only filesystems, such as squashfs?

-- 
Thanks,
//richard

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-06-01  7:48 ` Richard Weinberger
@ 2018-06-01  9:11   ` Gao Xiang
  2018-06-01  9:28     ` Richard Weinberger
  0 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-06-01  9:11 UTC (permalink / raw)
  To: Richard Weinberger
  Cc: LKML, linux-fsdevel, miaoxie, yuchao0, sunqiuyang, fangwei1,
	liguifu2, weidu.du, chen.chun.yen, brooke.wangzhigang,
	dongjinguang

Hi Richard,

On 2018/6/1 15:48, Richard Weinberger wrote:
> On Thu, May 31, 2018 at 1:06 PM, Gao Xiang <gaoxiang25@huawei.com> wrote:
>> Hi all,
>>
>> Read-only file systems are used in many cases, such as read-only storage media.
>> We are now focusing on the Android device which several read-only partitions exist.
>> Due to limited read-only solutions, a new read-only file system EROFS
>> (Extendable Read-Only File System) is introduced.
> 
> In which sense is it extendable?

Actually, the meaning of an enhanced (means not just read-only, but with the scalable
on-disk layout, compression, or fs-verify in the future) read-only file system is emphasized.

We also think of other candidate full names, such as
Enhanced / Extented Read-only File System, all the names short for "erofs" are okay.

> 
>> As the other read-only file systems, several meta regions in generic file systems
>> such as free space bitmap are omitted. But the difference is that EROFS focuses
>> more on performance than purely on saving storage space as much as possible.
>>
>> Furthermore, we also add the compression support called z_erofs.
>>
>> Traditional file systems with the compression support use the fixed-sized input
>> compression, the output compressed units could be arbitrary lengths.
>> However, data is accessed in the block unit for block devices, which means
>> (A) if the accessed compressed data is not buffered, some data read from
>> the physical block cannot be further utilized, which is illustrated as follows:
>>
>>    ++-----------++-----------++         ++-----------++-----------++
>> ...||           ||           ||   ...   ||           ||           ||  ... original data
>>    ++-----------++-----------++         ++-----------++-----------++
>>     \                         /          \                         /
>>        \                   /                \                    /
>>           \             /                      \               /
>>       ++---|-------++--|--------++       ++-----|----++--------|--++
>>       ||xxx|       ||  |xxxxxxxx||  ...  ||xxxxx|    ||        |xx||  compressed data
>>       ++---|-------++--|--------++       ++-----|----++--------|--++
>>
>> The shadow regions read from the block device but cannot be used for decompression.
>>
>> (B) If the compressed data is also buffered, it will increase the memory overhead.
>> Because these are compressed data, it cannot be directly used, and we don't know
>> when the corresponding compressed blocks are accessed, which is not friendly to
>> the random read.
>>
>> In order to reduce the proportion of the data which cannot be directly decompressed,
>> larger compressed sizes are preferred to be selected, which is also not friendly to
>> the random read.
>>
>> Erofs implements the compression in a different approach, the details of which will
>> be discussed in the next section.
>>
>> In brief, the following points summarize our design at a high level:
>>
>> 1) Use page-sized blocks so that there are no buffer heads.
>>
>> 2) By introducing a more general inline data / xattr, metadata and small data have
>> the opportunity to be read with the inode metadata at the same time.
>>
>> 3) Introduce another shared xattr region in order to store the common xattrs (eg.
>> selinux labels) or xattrs too large to be suitable for meta inline.
>>
>> 4) Metadata and data could be mixed by design, so it could be more flexible for mkfs
>> to organize files and data.
>>
>> 5) instead of using the fixed-sized input compression, we put forward a new fixed
>> output compression to make the full use of IO (which means all data from IO can be
>> decompressed), reduce the read amplification, improve random read and keep the
>> relatively lower compression ratios, illustrated as follows:
>>
>>
>>         |---- varient-length extent ----|------ VLE ------|---  VLE ---|
>>          /> clusterofs                  /> clusterofs     /> clusterofs /> clusterofs
>>    ++---|-------++-----------++---------|-++-----------++-|---------++-|
>> ...||   |       ||           ||         | ||           || |         || | ... original data
>>    ++---|-------++-----------++---------|-++-----------++-|---------++-|
>>    ++->cluster<-++->cluster<-++->cluster<-++->cluster<-++->cluster<-++
>>         size         size         size         size         size
>>          \                             /                 /            /
>>           \                      /              /            /
>>            \               /            /            /
>>             ++-----------++-----------++-----------++
>>         ... ||           ||           ||           || ... compressed clusters
>>             ++-----------++-----------++-----------++
>>             ++->cluster<-++->cluster<-++->cluster<-++
>>                  size         size         size
>>
>>    A cluster could have more than one blocks by design, but currently we only have the
>> page-sized cluster implementation (page-sized fixed output compression can also have
>> better compression ratio than fixed input compression).
>>
>>    All compressed clusters have a fixed size but could be decompressed into extents with
>> arbitrary lengths.
>>
>>    In addition, if a buffered IO reads the following shadow region (x), we could make a more
>>    customized path (to replace generic_file_buffered_read) which only reads one compressed
>>    cluster and makes the partial page available.
>>          /> clusterofs
>>    ++---|-------++
>> ...||   | xxxx  || ...
>>    ||---|-------||
>>
>> Some numbers using fixed output compression (VLE, cluster size = block size = 4k) on
>> the server and Android phone (kirin970 platform):
>>
>> Server (magnetic disk):
>>
>> compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
>> ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)
>>
>>   4              480.3          502.5                   69.8               11.1
>>  10              472.3          503.3                   56.4               10.0
>>  15              457.6          495.3                   47.0               10.9
>>  26              401.5          511.2                   34.7               11.1
>>  35              389.1          512.5                   28.0               11.0
>>  48              375.4          496.5                   23.2               10.6
>>  53              370.2          512.0                   21.8               11.0
>>  66              349.2          512.0                   19.0               11.4
>>  76              310.5          497.3                   17.3               11.6
>>  85              301.2          512.0                   16.0               11.0
>>  94              292.7          496.5                   14.6               11.1
>> 100              538.9          512.0                   11.4               10.8
>>
>> Kirin970 (A73 Big-core 2361Mhz, A53 little-core 0Mhz, DDR 1866Mhz):
> 
> What storage was used? An eMMC?

UFS device, fio with psync, bs=4k, iodepth=1.

> 
>> compression  EROFS seq read  EXT4 seq read        EROFS random read  EXT4 random read
>> ratio           bw[MB/s]       bw[MB/s]             bw[MB/s] (20%)    bw[MB/s] (20%)
>>
>>   4              546.7          544.3                    157.7              57.9
>>  10              535.7          521.0                    152.7              62.0
>>  15              529.0          520.3                    125.0              65.0
>>  26              418.0          526.3                     97.6              63.7
>>  35              367.7          511.7                     89.0              63.7
>>  48              415.7          500.7                     78.2              61.2
>>  53              423.0          566.7                     72.8              62.9
>>  66              334.3          537.3                     69.8              58.3
>>  76              387.3          546.0                     65.2              56.0
>>  85              306.3          546.0                     63.8              57.7
>>  94              345.0          589.7                     59.2              49.9
>> 100              579.7          556.7                     62.1              57.7
> 
> How does it compare to existing read only filesystems, such as squashfs?
> 

You are quite right.

We are now focusing on improving our decompression subsystem and
these numbers will be successively added in the future non-RFC patches.

We haven't pay much attention on comparing squashfs and erofs
yet since we once tried to use squashfs on our products with
different block sizes several years ago, it behaves
unacceptable in the low free memory scenario besides its
performance.


This version patchset is mainly used for the opensource archive.


Thanks for your attention :)


Thanks,

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-06-01  9:11   ` Gao Xiang
@ 2018-06-01  9:28     ` Richard Weinberger
  2018-06-01 11:16       ` Gao Xiang
  2018-07-27  0:55       ` Joey Pabalinas
  0 siblings, 2 replies; 58+ messages in thread
From: Richard Weinberger @ 2018-06-01  9:28 UTC (permalink / raw)
  To: Gao Xiang, LKML
  Cc: linux-fsdevel, miaoxie, yuchao0, sunqiuyang, fangwei1, liguifu2,
	weidu.du, chen.chun.yen, brooke.wangzhigang, dongjinguang

Am Freitag, 1. Juni 2018, 11:11:21 CEST schrieb Gao Xiang:
> > In which sense is it extendable?
> 
> Actually, the meaning of an enhanced (means not just read-only, but with the scalable
> on-disk layout, compression, or fs-verify in the future) read-only file system is emphasized.

ah ok.
 
> We also think of other candidate full names, such as
> Enhanced / Extented Read-only File System, all the names short for "erofs" are okay.

TBH, I read "erofs" as "error fs". ;-)

> > How does it compare to existing read only filesystems, such as squashfs?
> > 
> 
> You are quite right.
> 
> We are now focusing on improving our decompression subsystem and
> these numbers will be successively added in the future non-RFC patches.
> 
> We haven't pay much attention on comparing squashfs and erofs
> yet since we once tried to use squashfs on our products with
> different block sizes several years ago, it behaves
> unacceptable in the low free memory scenario besides its
> performance.

I'm interested in the comparison because I use squashfs often
for embedded devices on top of ubiblock (raw nand).
If there is something that can do better, I'm all for it.

Thanks,
//richard

-- 
sigma star gmbh - Eduard-Bodem-Gasse 6 - 6020 Innsbruck - Austria
ATU66964118 - FN 374287y

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-06-01  9:28     ` Richard Weinberger
@ 2018-06-01 11:16       ` Gao Xiang
  2018-06-07 10:26         ` Pavel Machek
  2018-07-27  0:55       ` Joey Pabalinas
  1 sibling, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-06-01 11:16 UTC (permalink / raw)
  To: Richard Weinberger
  Cc: LKML, linux-fsdevel, miaoxie, yuchao0, sunqiuyang, fangwei1,
	liguifu2, weidu.du, chen.chun.yen, brooke.wangzhigang,
	dongjinguang



On 2018/6/1 17:28, Richard Weinberger wrote:
> Am Freitag, 1. Juni 2018, 11:11:21 CEST schrieb Gao Xiang:
>>> In which sense is it extendable?
>>
>> Actually, the meaning of an enhanced (means not just read-only, but with the scalable
>> on-disk layout, compression, or fs-verify in the future) read-only file system is emphasized.
> 
> ah ok.
>  
>> We also think of other candidate full names, such as
>> Enhanced / Extented Read-only File System, all the names short for "erofs" are okay.
> 
> TBH, I read "erofs" as "error fs". ;-)
eh..."erofs" indeed comes from the EROFS error code, that is a playful behaviour...
I think the error code of EROFS is not so bad... :'(


Also hope for a better name but not only highlight the compression...
We have some further plans other than the compression.

Anyway, the name is currently not vital tho. :D

> 
>>> How does it compare to existing read only filesystems, such as squashfs?
>>>
>>
>> You are quite right.
>>
>> We are now focusing on improving our decompression subsystem and
>> these numbers will be successively added in the future non-RFC patches.
>>
>> We haven't pay much attention on comparing squashfs and erofs
>> yet since we once tried to use squashfs on our products with
>> different block sizes several years ago, it behaves
>> unacceptable in the low free memory scenario besides its
>> performance.
> 
> I'm interested in the comparison because I use squashfs often
> for embedded devices on top of ubiblock (raw nand).
> If there is something that can do better, I'm all for it.
> 

We're trying our best. ;)

> Thanks,
> //richard
> 

Thanks,

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-06-01 11:16       ` Gao Xiang
@ 2018-06-07 10:26         ` Pavel Machek
  0 siblings, 0 replies; 58+ messages in thread
From: Pavel Machek @ 2018-06-07 10:26 UTC (permalink / raw)
  To: Gao Xiang
  Cc: Richard Weinberger, LKML, linux-fsdevel, miaoxie, yuchao0,
	sunqiuyang, fangwei1, liguifu2, weidu.du, chen.chun.yen,
	brooke.wangzhigang, dongjinguang

Hi!

> >> We also think of other candidate full names, such as
> >> Enhanced / Extented Read-only File System, all the names short for "erofs" are okay.
> > 
> > TBH, I read "erofs" as "error fs". ;-)
> eh..."erofs" indeed comes from the EROFS error code, that is a playful behaviour...
> I think the error code of EROFS is not so bad... :'(

For the record, I understood the wordplay before I seen the
explanation, and I like it :-).
							Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-05-31 11:06 [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system Gao Xiang
  2018-06-01  7:48 ` Richard Weinberger
@ 2018-07-26 12:21 ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 01/25] staging: erofs: add on-disk layout Gao Xiang
                     ` (26 more replies)
  1 sibling, 27 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

Hi,

This is actually the 2nd patchset of erofs file system,
the original patchset can be found at

Link: https://marc.info/?l=linux-fsdevel&m=152776480425624

In order to keep up with the mainline linux-kernel changes and
improve it in a more active and timely manner, we put forword
this upstream proposal for linux-staging.

EROFS file system is a read-only file system with compression
support designed for certain devices (especially embeded
devices) with very limited physical memory and lots of memory
consumers, such as Android devices. It aimes to provide
a complete compression solution for such devices focuing
on high performance and little extra memory overhead.

It is perferred to select larger compressed cluster sizes
(generally >= 128k) for traditional compression file systems.
It reads and decompresses a large compressed cluster at once,
which has a good-looking random read number when memory
is sufficient because all historial decompressed data
is expected to be cached in memory. However, it also
induces destructive effects when such devices have no enough
spare memory for caching and decompression.

EROFS file system acts in some different way. It uses
fixed-sized compressed size rather than fixed-sized input
size, namely VLE (variable-length extent) compression,
which has at least three adventages:

 1) all data read from block device at once can be
    utilized, and read amplification can be easier to
    estimate and control;
 2) generally, it has a better compression ratio than
    fixed-sized input compression approaches configured
    with the same size;
 3) aggressively optimized paths such as partial page
    read can be implemented to gain better performance
    for page-unaligned read (unimplemented yet, in TODO list).

As can be seen, VLE compression does a great job in small
compressed cluster sizes, which is of course suitable for
devices with limited memory. In this patchset, an in-place
decompresion is also introduced to minimize extra memory usage.


Apart from compression, EROFS also has the following features
available and some limits:
 o page-sized block support (currently, and no buffer-head);
 o 32-bit block address (16TB for 4KB block);
 o selectable v1 (32 bytes) / v2 (64 bytes) inode;
 o 32-bit / 64-bit file size;
 o 64-bit node number for addressing inodes;
 o 64-bit s and 32-bit ns timestamps;
 o inline data support;
 o inline and shared xattr support;
 o metadata and data can be mixed (optional);
 o special inode support;
 o posix acl support.


The file system is still actively WIP, see _TODO_ for more details.

Any comments are welcome. :)


Change log from the original patchset
=====================================

 o Introduce a new erofs decompression subsystem, which has
   better sequencial read than the original patchset, and
   its random read remains almost the same (note that erofs
   still only fully support page-sized compressed cluster as
   the compression unit, however some additional code enabling
   larger compressed clustersizes is also added in this version);

 o Avoid LINUX_VERSION macros for linux-staging upstream

 o several bugfix and cleanup


Short log
=========

Chao Yu (3):
  staging: erofs: support special inode
  staging: erofs: introduce error injection infrastructure
  staging: erofs: support tracepoint

Gao Xiang (22):
  staging: erofs: add on-disk layout
  staging: erofs: add erofs in-memory stuffs
  staging: erofs: add super block operations
  staging: erofs: add raw address_space operations
  staging: erofs: add inode operations
  staging: erofs: add directory operations
  staging: erofs: add namei functions
  staging: erofs: update Kconfig and Makefile
  staging: erofs: introduce xattr & acl support
  staging: erofs: <linux/tagptr.h>: introduce tagged pointer
  staging: erofs: introduce pagevec for unzip subsystem
  staging: erofs: add erofs_map_blocks_iter
  staging: erofs: add erofs_allocpage
  staging: erofs: globalize prepare_bio and __submit_bio
  staging: erofs: introduce a customized LZ4 decompression
  staging: erofs: add a generic z_erofs VLE decompressor
  staging: erofs: introduce superblock registration
  staging: erofs: introduce erofs shrinker
  staging: erofs: introduce workstation for decompression
  staging: erofs: introduce VLE decompression support
  staging: erofs: introduce cached decompression
  staging: erofs: add a TODO and update MAINTAINERS for staging

 MAINTAINERS                                        |    7 +
 drivers/staging/Kconfig                            |    2 +
 drivers/staging/Makefile                           |    1 +
 drivers/staging/erofs/Kconfig                      |  141 ++
 drivers/staging/erofs/Makefile                     |   13 +
 drivers/staging/erofs/TODO                         |   45 +
 drivers/staging/erofs/data.c                       |  385 +++++
 drivers/staging/erofs/dir.c                        |  145 ++
 drivers/staging/erofs/erofs_fs.h                   |  266 ++++
 drivers/staging/erofs/include/linux/tagptr.h       |  110 ++
 drivers/staging/erofs/include/trace/events/erofs.h |  240 +++
 drivers/staging/erofs/inode.c                      |  283 ++++
 drivers/staging/erofs/internal.h                   |  556 +++++++
 drivers/staging/erofs/lz4defs.h                    |  227 +++
 drivers/staging/erofs/namei.c                      |  251 +++
 drivers/staging/erofs/super.c                      |  649 ++++++++
 drivers/staging/erofs/unzip_lz4.c                  |  251 +++
 drivers/staging/erofs/unzip_pagevec.h              |  172 +++
 drivers/staging/erofs/unzip_vle.c                  | 1634 ++++++++++++++++++++
 drivers/staging/erofs/unzip_vle.h                  |  239 +++
 drivers/staging/erofs/unzip_vle_lz4.c              |  209 +++
 drivers/staging/erofs/utils.c                      |  270 ++++
 drivers/staging/erofs/xattr.c                      |  579 +++++++
 drivers/staging/erofs/xattr.h                      |   93 ++
 24 files changed, 6768 insertions(+)
 create mode 100644 drivers/staging/erofs/Kconfig
 create mode 100644 drivers/staging/erofs/Makefile
 create mode 100644 drivers/staging/erofs/TODO
 create mode 100644 drivers/staging/erofs/data.c
 create mode 100644 drivers/staging/erofs/dir.c
 create mode 100644 drivers/staging/erofs/erofs_fs.h
 create mode 100644 drivers/staging/erofs/include/linux/tagptr.h
 create mode 100644 drivers/staging/erofs/include/trace/events/erofs.h
 create mode 100644 drivers/staging/erofs/inode.c
 create mode 100644 drivers/staging/erofs/internal.h
 create mode 100644 drivers/staging/erofs/lz4defs.h
 create mode 100644 drivers/staging/erofs/namei.c
 create mode 100644 drivers/staging/erofs/super.c
 create mode 100644 drivers/staging/erofs/unzip_lz4.c
 create mode 100644 drivers/staging/erofs/unzip_pagevec.h
 create mode 100644 drivers/staging/erofs/unzip_vle.c
 create mode 100644 drivers/staging/erofs/unzip_vle.h
 create mode 100644 drivers/staging/erofs/unzip_vle_lz4.c
 create mode 100644 drivers/staging/erofs/utils.c
 create mode 100644 drivers/staging/erofs/xattr.c
 create mode 100644 drivers/staging/erofs/xattr.h

Thanks,
Gao Xiang

-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 01/25] staging: erofs: add on-disk layout
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 02/25] staging: erofs: add erofs in-memory stuffs Gao Xiang
                     ` (25 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This commit adds the on-disk layout header file of erofs.

Note that the on-disk layout is still WIP, and some fields are
reserved for the future use by design.

Any comments are welcome.

Thanks-to: Li Guifu <liguifu2@huawei.com>
Thanks-to: Sun Qiuyang <sunqiuyang@huawei.com>
Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/erofs_fs.h | 266 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 266 insertions(+)
 create mode 100644 drivers/staging/erofs/erofs_fs.h

diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h
new file mode 100644
index 0000000..2f8e2bf
--- /dev/null
+++ b/drivers/staging/erofs/erofs_fs.h
@@ -0,0 +1,266 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Apache-2.0
+ *
+ * linux/drivers/staging/erofs/erofs_fs.h
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is dual-licensed; you may select either the GNU General Public
+ * License version 2 or Apache License, Version 2.0. See the file COPYING
+ * in the main directory of the Linux distribution for more details.
+ */
+#ifndef __EROFS_FS_H
+#define __EROFS_FS_H
+
+/* Enhanced(Extended) ROM File System */
+#define EROFS_SUPER_MAGIC_V1    0xE0F5E1E2
+#define EROFS_SUPER_OFFSET      1024
+
+struct erofs_super_block {
+/*  0 */__le32 magic;           /* in the little endian */
+/*  4 */__le32 checksum;        /* crc32c(super_block) */
+/*  8 */__le32 features;
+/* 12 */__u8 blkszbits;         /* support block_size == PAGE_SIZE only */
+/* 13 */__u8 reserved;
+
+/* 14 */__le16 root_nid;
+/* 16 */__le64 inos;            /* total valid ino # (== f_files - f_favail) */
+
+/* 24 */__le64 build_time;      /* inode v1 time derivation */
+/* 32 */__le32 build_time_nsec;
+/* 36 */__le32 blocks;          /* used for statfs */
+/* 40 */__le32 meta_blkaddr;
+/* 44 */__le32 xattr_blkaddr;
+/* 48 */__u8 uuid[16];          /* 128-bit uuid for volume */
+/* 64 */__u8 volume_name[16];   /* volume name */
+
+/* 80 */__u8 reserved2[48];     /* 128 bytes */
+} __packed;
+
+#define __EROFS_BIT(_prefix, _cur, _pre)	enum {	\
+	_prefix ## _cur ## _BIT = _prefix ## _pre ## _BIT + \
+		_prefix ## _pre ## _BITS }
+
+/*
+ * erofs inode data mapping:
+ * 0 - inode plain without inline data A:
+ * inode, [xattrs], ... | ... | no-holed data
+ * 1 - inode VLE compression B:
+ * inode, [xattrs], extents ... | ...
+ * 2 - inode plain with inline data C:
+ * inode, [xattrs], last_inline_data, ... | ... | no-holed data
+ * 3~7 - reserved
+ */
+enum {
+	EROFS_INODE_LAYOUT_PLAIN,
+	EROFS_INODE_LAYOUT_COMPRESSION,
+	EROFS_INODE_LAYOUT_INLINE,
+	EROFS_INODE_LAYOUT_MAX
+};
+#define EROFS_I_VERSION_BITS            1
+#define EROFS_I_DATA_MAPPING_BITS       3
+
+#define EROFS_I_VERSION_BIT             0
+__EROFS_BIT(EROFS_I_, DATA_MAPPING, VERSION);
+
+struct erofs_inode_v1 {
+/*  0 */__le16 i_advise;
+
+/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
+/*  2 */__le16 i_xattr_icount;
+/*  4 */__le16 i_mode;
+/*  6 */__le16 i_nlink;
+/*  8 */__le32 i_size;
+/* 12 */__le32 i_reserved;
+/* 16 */union {
+		/* file total compressed blocks for data mapping 1 */
+		__le32 compressed_blocks;
+		__le32 raw_blkaddr;
+
+		/* for device files, used to indicate old/new device # */
+		__le32 rdev;
+	} i_u __packed;
+/* 20 */__le32 i_ino;           /* only used for 32-bit stat compatibility */
+/* 24 */__le16 i_uid;
+/* 26 */__le16 i_gid;
+/* 28 */__le32 i_checksum;
+} __packed;
+
+/* 32 bytes on-disk inode */
+#define EROFS_INODE_LAYOUT_V1   0
+/* 64 bytes on-disk inode */
+#define EROFS_INODE_LAYOUT_V2   1
+
+struct erofs_inode_v2 {
+	__le16 i_advise;
+
+	/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
+	__le16 i_xattr_icount;
+	__le16 i_mode;
+	__le16 i_reserved;      /* 8 bytes */
+	__le64 i_size;          /* 16 bytes */
+	union {
+		/* file total compressed blocks for data mapping 1 */
+		__le32 compressed_blocks;
+		__le32 raw_blkaddr;
+
+		/* for device files, used to indicate old/new device # */
+		__le32 rdev;
+	} i_u __packed;
+
+	/* only used for 32-bit stat compatibility */
+	__le32 i_ino;           /* 24 bytes */
+
+	__le32 i_uid;
+	__le32 i_gid;
+	__le64 i_ctime;         /* 32 bytes */
+	__le32 i_ctime_nsec;
+	__le32 i_nlink;
+	__u8   i_reserved2[12];
+	__le32 i_checksum;      /* 64 bytes */
+} __packed;
+
+#define EROFS_MAX_SHARED_XATTRS         (128)
+/* h_shared_count between 129 ... 255 are special # */
+#define EROFS_SHARED_XATTR_EXTENT       (255)
+
+/*
+ * inline xattrs (n == i_xattr_icount):
+ * erofs_xattr_ibody_header(1) + (n - 1) * 4 bytes
+ *          12 bytes           /                   \
+ *                            /                     \
+ *                           /-----------------------\
+ *                           |  erofs_xattr_entries+ |
+ *                           +-----------------------+
+ * inline xattrs must starts in erofs_xattr_ibody_header,
+ * for read-only fs, no need to introduce h_refcount
+ */
+struct erofs_xattr_ibody_header {
+	__le32 h_checksum;
+	__u8   h_shared_count;
+	__u8   h_reserved[7];
+	__le32 h_shared_xattrs[0];      /* shared xattr id array */
+} __packed;
+
+/* Name indexes */
+#define EROFS_XATTR_INDEX_USER              1
+#define EROFS_XATTR_INDEX_POSIX_ACL_ACCESS  2
+#define EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
+#define EROFS_XATTR_INDEX_TRUSTED           4
+#define EROFS_XATTR_INDEX_LUSTRE            5
+#define EROFS_XATTR_INDEX_SECURITY          6
+
+/* xattr entry (for both inline & shared xattrs) */
+struct erofs_xattr_entry {
+	__u8   e_name_len;      /* length of name */
+	__u8   e_name_index;    /* attribute name index */
+	__le16 e_value_size;    /* size of attribute value */
+	/* followed by e_name and e_value */
+	char   e_name[0];       /* attribute name */
+} __packed;
+
+#define ondisk_xattr_ibody_size(count)	({\
+	u32 __count = le16_to_cpu(count); \
+	((__count) == 0) ? 0 : \
+	sizeof(struct erofs_xattr_ibody_header) + \
+		sizeof(__u32) * ((__count) - 1); })
+
+#define EROFS_XATTR_ALIGN(size) round_up(size, sizeof(struct erofs_xattr_entry))
+#define EROFS_XATTR_ENTRY_SIZE(entry) EROFS_XATTR_ALIGN( \
+	sizeof(struct erofs_xattr_entry) + \
+	(entry)->e_name_len + le16_to_cpu((entry)->e_value_size))
+
+/* have to be aligned with 8 bytes on disk */
+struct erofs_extent_header {
+	__le32 eh_checksum;
+	__le32 eh_reserved[3];
+} __packed;
+
+/*
+ * Z_EROFS Variable-sized Logical Extent cluster type:
+ *    0 - literal (uncompressed) cluster
+ *    1 - compressed cluster (for the head logical cluster)
+ *    2 - compressed cluster (for the other logical clusters)
+ *
+ * In detail,
+ *    0 - literal (uncompressed) cluster,
+ *        di_advise = 0
+ *        di_clusterofs = the literal data offset of the cluster
+ *        di_blkaddr = the blkaddr of the literal cluster
+ *
+ *    1 - compressed cluster (for the head logical cluster)
+ *        di_advise = 1
+ *        di_clusterofs = the decompressed data offset of the cluster
+ *        di_blkaddr = the blkaddr of the compressed cluster
+ *
+ *    2 - compressed cluster (for the other logical clusters)
+ *        di_advise = 2
+ *        di_clusterofs =
+ *           the decompressed data offset in its own head cluster
+ *        di_u.delta[0] = distance to its corresponding head cluster
+ *        di_u.delta[1] = distance to its corresponding tail cluster
+ *                (di_advise could be 0, 1 or 2)
+ */
+#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS        2
+#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT         0
+
+struct z_erofs_vle_decompressed_index {
+	__le16 di_advise;
+	/* where to decompress in the head cluster */
+	__le16 di_clusterofs;
+
+	union {
+		/* for the head cluster */
+		__le32 blkaddr;
+		/*
+		 * for the rest clusters
+		 * eg. for 4k page-sized cluster, maximum 4K*64k = 256M)
+		 * [0] - pointing to the head cluster
+		 * [1] - pointing to the tail cluster
+		 */
+		__le16 delta[2];
+	} di_u __packed;		/* 8 bytes */
+} __packed;
+
+#define Z_EROFS_VLE_EXTENT_ALIGN(size) round_up(size, \
+	sizeof(struct z_erofs_vle_decompressed_index))
+
+/* dirent sorts in alphabet order, thus we can do binary search */
+struct erofs_dirent {
+	__le64 nid;     /*  0, node number */
+	__le16 nameoff; /*  8, start offset of file name */
+	__u8 file_type; /* 10, file type */
+	__u8 reserved;  /* 11, reserved */
+} __packed;
+
+/* file types used in inode_info->flags */
+enum {
+	EROFS_FT_UNKNOWN,
+	EROFS_FT_REG_FILE,
+	EROFS_FT_DIR,
+	EROFS_FT_CHRDEV,
+	EROFS_FT_BLKDEV,
+	EROFS_FT_FIFO,
+	EROFS_FT_SOCK,
+	EROFS_FT_SYMLINK,
+	EROFS_FT_MAX
+};
+
+#define EROFS_NAME_LEN      255
+
+/* check the EROFS on-disk layout strictly at compile time */
+static inline void erofs_check_ondisk_layout_definitions(void)
+{
+	BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
+	BUILD_BUG_ON(sizeof(struct erofs_inode_v1) != 32);
+	BUILD_BUG_ON(sizeof(struct erofs_inode_v2) != 64);
+	BUILD_BUG_ON(sizeof(struct erofs_xattr_ibody_header) != 12);
+	BUILD_BUG_ON(sizeof(struct erofs_xattr_entry) != 4);
+	BUILD_BUG_ON(sizeof(struct erofs_extent_header) != 16);
+	BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8);
+	BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
+}
+
+#endif
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 02/25] staging: erofs: add erofs in-memory stuffs
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
  2018-07-26 12:21   ` [PATCH 01/25] staging: erofs: add on-disk layout Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 03/25] staging: erofs: add super block operations Gao Xiang
                     ` (24 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

 - erofs_sb_info:
   contains erofs-specific in-memory information.

 - erofs_vnode:
   contains vfs_inode and other fs-specific information.
   same as super block, the only one in-memory definition exists.

 - erofs_map_blocks
   plays a role in the file L2P mapping

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/internal.h | 281 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 281 insertions(+)
 create mode 100644 drivers/staging/erofs/internal.h

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
new file mode 100644
index 0000000..d0992d2
--- /dev/null
+++ b/drivers/staging/erofs/internal.h
@@ -0,0 +1,281 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/drivers/staging/erofs/internal.h
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#ifndef __INTERNAL_H
+#define __INTERNAL_H
+
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/cleancache.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "erofs_fs.h"
+
+/* redefine pr_fmt "erofs: " */
+#undef pr_fmt
+#define pr_fmt(fmt) "erofs: " fmt
+
+#define errln(x, ...)   pr_err(x "\n", ##__VA_ARGS__)
+#define infoln(x, ...)  pr_info(x "\n", ##__VA_ARGS__)
+#ifdef CONFIG_EROFS_FS_DEBUG
+#define debugln(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
+
+#define dbg_might_sleep         might_sleep
+#define DBG_BUGON               BUG_ON
+#else
+#define debugln(x, ...)         ((void)0)
+
+#define dbg_might_sleep()       ((void)0)
+#define DBG_BUGON(...)          ((void)0)
+#endif
+
+/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
+#define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
+
+typedef u64 erofs_nid_t;
+
+struct erofs_sb_info {
+	u32 blocks;
+	u32 meta_blkaddr;
+
+	/* inode slot unit size in bit shift */
+	unsigned char islotbits;
+
+	u32 build_time_nsec;
+	u64 build_time;
+
+	/* what we really care is nid, rather than ino.. */
+	erofs_nid_t root_nid;
+	/* used for statfs, f_files - f_favail */
+	u64 inos;
+
+	u8 uuid[16];                    /* 128-bit uuid for volume */
+	u8 volume_name[16];             /* volume name */
+	char *dev_name;
+
+	unsigned int mount_opt;
+};
+
+#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
+#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
+
+#define clear_opt(sbi, option)	((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(sbi, option)	((sbi)->mount_opt & EROFS_MOUNT_##option)
+
+/* we strictly follow PAGE_SIZE and no buffer head yet */
+#define LOG_BLOCK_SIZE		PAGE_SHIFT
+
+#undef LOG_SECTORS_PER_BLOCK
+#define LOG_SECTORS_PER_BLOCK	(PAGE_SHIFT - 9)
+
+#undef SECTORS_PER_BLOCK
+#define SECTORS_PER_BLOCK	(1 << SECTORS_PER_BLOCK)
+
+#define EROFS_BLKSIZ		(1 << LOG_BLOCK_SIZE)
+
+#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
+#error erofs cannot be used in this platform
+#endif
+
+#define ROOT_NID(sb)		((sb)->root_nid)
+
+typedef u64 erofs_off_t;
+
+/* data type for filesystem-wide blocks number */
+typedef u32 erofs_blk_t;
+
+#define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
+#define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
+#define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+
+static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
+{
+	return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
+}
+
+#define inode_set_inited_xattr(inode)   (EROFS_V(inode)->flags |= 1)
+#define inode_has_inited_xattr(inode)   (EROFS_V(inode)->flags & 1)
+
+struct erofs_vnode {
+	erofs_nid_t nid;
+	unsigned int flags;
+
+	unsigned char data_mapping_mode;
+	/* inline size in bytes */
+	unsigned char inode_isize;
+	unsigned short xattr_isize;
+
+	unsigned xattr_shared_count;
+	unsigned *xattr_shared_xattrs;
+
+	erofs_blk_t raw_blkaddr;
+
+	/* the corresponding vfs inode */
+	struct inode vfs_inode;
+};
+
+#define EROFS_V(ptr)	\
+	container_of(ptr, struct erofs_vnode, vfs_inode)
+
+#define __inode_advise(x, bit, bits) \
+	(((x) >> (bit)) & ((1 << (bits)) - 1))
+
+#define __inode_version(advise)	\
+	__inode_advise(advise, EROFS_I_VERSION_BIT,	\
+		EROFS_I_VERSION_BITS)
+
+#define __inode_data_mapping(advise)	\
+	__inode_advise(advise, EROFS_I_DATA_MAPPING_BIT,\
+		EROFS_I_DATA_MAPPING_BITS)
+
+static inline unsigned long inode_datablocks(struct inode *inode)
+{
+	/* since i_size cannot be changed */
+	return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+}
+
+static inline bool is_inode_layout_plain(struct inode *inode)
+{
+	return EROFS_V(inode)->data_mapping_mode == EROFS_INODE_LAYOUT_PLAIN;
+}
+
+static inline bool is_inode_layout_compression(struct inode *inode)
+{
+	return EROFS_V(inode)->data_mapping_mode ==
+					EROFS_INODE_LAYOUT_COMPRESSION;
+}
+
+static inline bool is_inode_layout_inline(struct inode *inode)
+{
+	return EROFS_V(inode)->data_mapping_mode == EROFS_INODE_LAYOUT_INLINE;
+}
+
+extern const struct super_operations erofs_sops;
+extern const struct inode_operations erofs_dir_iops;
+extern const struct file_operations erofs_dir_fops;
+
+extern const struct address_space_operations erofs_raw_access_aops;
+
+/*
+ * Logical to physical block mapping, used by erofs_map_blocks()
+ *
+ * Different with other file systems, it is used for 2 access modes:
+ *
+ * 1) RAW access mode:
+ *
+ * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
+ * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
+ *
+ * Note that m_lblk in the RAW access mode refers to the number of
+ * the compressed ondisk block rather than the uncompressed
+ * in-memory block for the compressed file.
+ *
+ * m_pofs equals to m_lofs except for the inline data page.
+ *
+ * 2) Normal access mode:
+ *
+ * If the inode is not compressed, it has no difference with
+ * the RAW access mode. However, if the inode is compressed,
+ * users should pass a valid (m_lblk, m_lofs) pair, and get
+ * the needed m_pblk, m_pofs, m_len to get the compressed data
+ * and the updated m_lblk, m_lofs which indicates the start
+ * of the corresponding uncompressed data in the file.
+ */
+enum {
+	BH_Zipped = BH_PrivateStart,
+};
+
+/* Has a disk mapping */
+#define EROFS_MAP_MAPPED	(1 << BH_Mapped)
+/* Located in metadata (could be copied from bd_inode) */
+#define EROFS_MAP_META		(1 << BH_Meta)
+/* The extent has been compressed */
+#define EROFS_MAP_ZIPPED	(1 << BH_Zipped)
+
+struct erofs_map_blocks {
+	erofs_off_t m_pa, m_la;
+	u64 m_plen, m_llen;
+
+	unsigned int m_flags;
+};
+
+/* Flags used by erofs_map_blocks() */
+#define EROFS_GET_BLOCKS_RAW    0x0001
+
+/* data.c */
+extern struct page *erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio);
+extern int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
+
+static inline struct page *erofs_get_inline_page(struct inode *inode,
+	erofs_blk_t blkaddr)
+{
+	return erofs_get_meta_page(inode->i_sb,
+		blkaddr, S_ISDIR(inode->i_mode));
+}
+
+/* inode.c */
+extern struct inode *erofs_iget(struct super_block *sb,
+	erofs_nid_t nid, bool dir);
+
+/* dir.c */
+int erofs_namei(struct inode *dir, struct qstr *name,
+	erofs_nid_t *nid, unsigned *d_type);
+
+/* xattr.c */
+extern const struct xattr_handler *erofs_xattr_handlers[];
+
+/* symlink */
+static inline void set_inode_fast_symlink(struct inode *inode)
+{
+	inode->i_op = &simple_symlink_inode_operations;
+}
+
+static inline bool is_inode_fast_symlink(struct inode *inode)
+{
+	return inode->i_op == &simple_symlink_inode_operations;
+}
+
+static inline void *erofs_vmap(struct page **pages, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+	int i = 0;
+
+	while (1) {
+		void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL);
+		/* retry two more times (totally 3 times) */
+		if (addr != NULL || ++i >= 3)
+			return addr;
+		vm_unmap_aliases();
+	}
+	return NULL;
+#else
+	return vmap(pages, count, VM_MAP, PAGE_KERNEL);
+#endif
+}
+
+static inline void erofs_vunmap(const void *mem, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+	vm_unmap_ram(mem, count);
+#else
+	vunmap(mem);
+#endif
+}
+
+#endif
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 03/25] staging: erofs: add super block operations
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
  2018-07-26 12:21   ` [PATCH 01/25] staging: erofs: add on-disk layout Gao Xiang
  2018-07-26 12:21   ` [PATCH 02/25] staging: erofs: add erofs in-memory stuffs Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 04/25] staging: erofs: add raw address_space operations Gao Xiang
                     ` (23 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This commit adds erofs super block operations, including (u)mount,
remount_fs, show_options, statfs, in addition to some private
icache management functions.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/super.c | 415 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 415 insertions(+)
 create mode 100644 drivers/staging/erofs/super.c

diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
new file mode 100644
index 0000000..98ae03d
--- /dev/null
+++ b/drivers/staging/erofs/super.c
@@ -0,0 +1,415 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/super.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/statfs.h>
+#include <linux/parser.h>
+#include "internal.h"
+
+static struct kmem_cache *erofs_inode_cachep __read_mostly;
+
+static void init_once(void *ptr)
+{
+	struct erofs_vnode *vi = ptr;
+
+	inode_init_once(&vi->vfs_inode);
+}
+
+static int erofs_init_inode_cache(void)
+{
+	erofs_inode_cachep = kmem_cache_create("erofs_inode",
+		sizeof(struct erofs_vnode), 0,
+		SLAB_RECLAIM_ACCOUNT, init_once);
+
+	return erofs_inode_cachep != NULL ? 0 : -ENOMEM;
+}
+
+static void erofs_exit_inode_cache(void)
+{
+	BUG_ON(erofs_inode_cachep == NULL);
+	kmem_cache_destroy(erofs_inode_cachep);
+}
+
+static struct inode *alloc_inode(struct super_block *sb)
+{
+	struct erofs_vnode *vi =
+		kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
+
+	if (vi == NULL)
+		return NULL;
+
+	/* zero out everything except vfs_inode */
+	memset(vi, 0, offsetof(struct erofs_vnode, vfs_inode));
+	return &vi->vfs_inode;
+}
+
+static void i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	struct erofs_vnode *vi = EROFS_V(inode);
+
+	/* be careful RCU symlink path (see ext4_inode_info->i_data)! */
+	if (is_inode_fast_symlink(inode))
+		kfree(inode->i_link);
+
+	kfree(vi->xattr_shared_xattrs);
+
+	kmem_cache_free(erofs_inode_cachep, vi);
+}
+
+static void destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, i_callback);
+}
+
+static int superblock_read(struct super_block *sb)
+{
+	struct erofs_sb_info *sbi;
+	struct buffer_head *bh;
+	struct erofs_super_block *layout;
+	unsigned blkszbits;
+	int ret;
+
+	bh = sb_bread(sb, 0);
+
+	if (bh == NULL) {
+		errln("cannot read erofs superblock");
+		return -EIO;
+	}
+
+	sbi = EROFS_SB(sb);
+	layout = (struct erofs_super_block *)((u8 *)bh->b_data
+		 + EROFS_SUPER_OFFSET);
+
+	ret = -EINVAL;
+	if (le32_to_cpu(layout->magic) != EROFS_SUPER_MAGIC_V1) {
+		errln("cannot find valid erofs superblock");
+		goto out;
+	}
+
+	blkszbits = layout->blkszbits;
+	/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
+	if (unlikely(blkszbits != LOG_BLOCK_SIZE)) {
+		errln("blksize %u isn't supported on this platform",
+			1 << blkszbits);
+		goto out;
+	}
+
+	sbi->blocks = le32_to_cpu(layout->blocks);
+	sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
+	sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1;
+
+	sbi->root_nid = le16_to_cpu(layout->root_nid);
+	sbi->inos = le64_to_cpu(layout->inos);
+
+	sbi->build_time = le64_to_cpu(layout->build_time);
+	sbi->build_time_nsec = le32_to_cpu(layout->build_time_nsec);
+
+	memcpy(&sb->s_uuid, layout->uuid, sizeof(layout->uuid));
+	memcpy(sbi->volume_name, layout->volume_name,
+		sizeof(layout->volume_name));
+
+	ret = 0;
+out:
+	brelse(bh);
+	return ret;
+}
+
+static void default_options(struct erofs_sb_info *sbi)
+{
+}
+
+enum {
+	Opt_err
+};
+
+static match_table_t erofs_tokens = {
+	{Opt_err, NULL}
+};
+
+static int parse_options(struct super_block *sb, char *options)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *p;
+
+	if (!options)
+		return 0;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+
+		if (!*p)
+			continue;
+
+		args[0].to = args[0].from = NULL;
+		token = match_token(p, erofs_tokens, args);
+
+		switch (token) {
+		default:
+			errln("Unrecognized mount option \"%s\" "
+					"or missing value", p);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static int erofs_read_super(struct super_block *sb,
+	const char *dev_name, void *data, int silent)
+{
+	struct inode *inode;
+	struct erofs_sb_info *sbi;
+	int err = -EINVAL;
+
+	infoln("read_super, device -> %s", dev_name);
+	infoln("options -> %s", (char *)data);
+
+	if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
+		errln("failed to set erofs blksize");
+		goto err;
+	}
+
+	sbi = kzalloc(sizeof(struct erofs_sb_info), GFP_KERNEL);
+	if (unlikely(sbi == NULL)) {
+		err = -ENOMEM;
+		goto err;
+	}
+	sb->s_fs_info = sbi;
+
+	err = superblock_read(sb);
+	if (err)
+		goto err_sbread;
+
+	sb->s_magic = EROFS_SUPER_MAGIC;
+	sb->s_flags |= MS_RDONLY | MS_NOATIME;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_time_gran = 1;
+
+	sb->s_op = &erofs_sops;
+
+	/* set erofs default mount options */
+	default_options(sbi);
+
+	err = parse_options(sb, data);
+	if (err)
+		goto err_parseopt;
+
+	if (!silent)
+		infoln("root inode @ nid %llu", ROOT_NID(sbi));
+
+	/* get the root inode */
+	inode = erofs_iget(sb, ROOT_NID(sbi), true);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto err_iget;
+	}
+
+	if (!S_ISDIR(inode->i_mode)) {
+		errln("rootino(nid %llu) is not a directory(i_mode %o)",
+			ROOT_NID(sbi), inode->i_mode);
+		err = -EINVAL;
+		goto err_isdir;
+	}
+
+	sb->s_root = d_make_root(inode);
+	if (sb->s_root == NULL) {
+		err = -ENOMEM;
+		goto err_makeroot;
+	}
+
+	/* save the device name to sbi */
+	sbi->dev_name = __getname();
+	if (sbi->dev_name == NULL) {
+		err = -ENOMEM;
+		goto err_devname;
+	}
+
+	snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
+	sbi->dev_name[PATH_MAX - 1] = '\0';
+
+	/*
+	 * We already have a positive dentry, which was instantiated
+	 * by d_make_root. Just need to d_rehash it.
+	 */
+	d_rehash(sb->s_root);
+
+	if (!silent)
+		infoln("mounted on %s with opts: %s.", dev_name,
+			(char *)data);
+	return 0;
+	/*
+	 * please add a label for each exit point and use
+	 * the following name convention, thus new features
+	 * can be integrated easily without renaming labels.
+	 */
+err_devname:
+	dput(sb->s_root);
+err_makeroot:
+err_isdir:
+	if (sb->s_root == NULL)
+		iput(inode);
+err_iget:
+err_parseopt:
+err_sbread:
+	sb->s_fs_info = NULL;
+	kfree(sbi);
+err:
+	return err;
+}
+
+/*
+ * could be triggered after deactivate_locked_super()
+ * is called, thus including umount and failed to initialize.
+ */
+static void erofs_put_super(struct super_block *sb)
+{
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+
+	/* for cases which are failed in "read_super" */
+	if (sbi == NULL)
+		return;
+
+	WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
+
+	infoln("unmounted for %s", sbi->dev_name);
+	__putname(sbi->dev_name);
+
+	kfree(sbi);
+	sb->s_fs_info = NULL;
+}
+
+
+struct erofs_mount_private {
+	const char *dev_name;
+	char *options;
+};
+
+/* support mount_bdev() with options */
+static int erofs_fill_super(struct super_block *sb,
+	void *_priv, int silent)
+{
+	struct erofs_mount_private *priv = _priv;
+
+	return erofs_read_super(sb, priv->dev_name,
+		priv->options, silent);
+}
+
+static struct dentry *erofs_mount(
+	struct file_system_type *fs_type, int flags,
+	const char *dev_name, void *data)
+{
+	struct erofs_mount_private priv = {
+		.dev_name = dev_name,
+		.options = data
+	};
+
+	return mount_bdev(fs_type, flags, dev_name,
+		&priv, erofs_fill_super);
+}
+
+static void erofs_kill_sb(struct super_block *sb)
+{
+	kill_block_super(sb);
+}
+
+static struct file_system_type erofs_fs_type = {
+	.owner          = THIS_MODULE,
+	.name           = "erofs",
+	.mount          = erofs_mount,
+	.kill_sb        = erofs_kill_sb,
+	.fs_flags       = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("erofs");
+
+static int __init erofs_module_init(void)
+{
+	int err;
+
+	erofs_check_ondisk_layout_definitions();
+	infoln("initializing erofs " EROFS_VERSION);
+
+	err = erofs_init_inode_cache();
+	if (err)
+		goto icache_err;
+
+	err = register_filesystem(&erofs_fs_type);
+	if (err)
+		goto fs_err;
+
+	infoln("successfully to initialize erofs");
+	return 0;
+
+fs_err:
+	erofs_exit_inode_cache();
+icache_err:
+	return err;
+}
+
+static void __exit erofs_module_exit(void)
+{
+	unregister_filesystem(&erofs_fs_type);
+	erofs_exit_inode_cache();
+	infoln("successfully finalize erofs");
+}
+
+/* get filesystem statistics */
+static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type = sb->s_magic;
+	buf->f_bsize = EROFS_BLKSIZ;
+	buf->f_blocks = sbi->blocks;
+	buf->f_bfree = buf->f_bavail = 0;
+
+	buf->f_files = ULLONG_MAX;
+	buf->f_ffree = ULLONG_MAX - sbi->inos;
+
+	buf->f_namelen = EROFS_NAME_LEN;
+
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+	return 0;
+}
+
+static int erofs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	return 0;
+}
+
+static int erofs_remount(struct super_block *sb, int *flags, char *data)
+{
+	BUG_ON(!sb_rdonly(sb));
+
+	*flags |= MS_RDONLY;
+	return 0;
+}
+
+const struct super_operations erofs_sops = {
+	.put_super = erofs_put_super,
+	.alloc_inode = alloc_inode,
+	.destroy_inode = destroy_inode,
+	.statfs = erofs_statfs,
+	.show_options = erofs_show_options,
+	.remount_fs = erofs_remount,
+};
+
+module_init(erofs_module_init);
+module_exit(erofs_module_exit);
+
+MODULE_DESCRIPTION("Enhanced ROM File System");
+MODULE_AUTHOR("Gao Xiang, Yu Chao, Miao Xie, CONSUMER BG, HUAWEI Inc.");
+MODULE_LICENSE("GPL");
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 04/25] staging: erofs: add raw address_space operations
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (2 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 03/25] staging: erofs: add super block operations Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 05/25] staging: erofs: add inode operations Gao Xiang
                     ` (22 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This commit adds functions for meta and raw data, and also
provides address_space_operations for raw data access.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/data.c | 362 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 362 insertions(+)
 create mode 100644 drivers/staging/erofs/data.c

diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
new file mode 100644
index 0000000..4ddb5c0
--- /dev/null
+++ b/drivers/staging/erofs/data.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/data.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "internal.h"
+#include <linux/prefetch.h>
+
+static inline void read_endio(struct bio *bio)
+{
+	int i;
+	struct bio_vec *bvec;
+	const blk_status_t err = bio->bi_status;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		/* page is already locked */
+		BUG_ON(PageUptodate(page));
+
+		if (unlikely(err))
+			SetPageError(page);
+		else
+			SetPageUptodate(page);
+
+		unlock_page(page);
+		/* page could be reclaimed now */
+	}
+	bio_put(bio);
+}
+
+static void __submit_bio(struct bio *bio, unsigned op, unsigned op_flags)
+{
+	bio_set_op_attrs(bio, op, op_flags);
+	submit_bio(bio);
+}
+
+static struct bio *prepare_bio(struct super_block *sb,
+	erofs_blk_t blkaddr, unsigned nr_pages)
+{
+	struct bio *bio = bio_alloc(GFP_NOIO | __GFP_NOFAIL, nr_pages);
+
+	BUG_ON(bio == NULL);
+
+	bio->bi_end_io = read_endio;
+	bio_set_dev(bio, sb->s_bdev);
+	bio->bi_iter.bi_sector = blkaddr << LOG_SECTORS_PER_BLOCK;
+
+	return bio;
+}
+
+/* prio -- true is used for dir */
+struct page *erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio)
+{
+	struct inode *bd_inode = sb->s_bdev->bd_inode;
+	struct address_space *mapping = bd_inode->i_mapping;
+	struct page *page;
+
+repeat:
+	page = find_or_create_page(mapping, blkaddr,
+	/*
+	 * Prefer looping in the allocator rather than here,
+	 * at least that code knows what it's doing.
+	 */
+		mapping_gfp_constraint(mapping, ~__GFP_FS) | __GFP_NOFAIL);
+
+	BUG_ON(!page || !PageLocked(page));
+
+	if (!PageUptodate(page)) {
+		struct bio *bio;
+		int err;
+
+		bio = prepare_bio(sb, blkaddr, 1);
+		err = bio_add_page(bio, page, PAGE_SIZE, 0);
+		BUG_ON(err != PAGE_SIZE);
+
+		__submit_bio(bio, REQ_OP_READ,
+			REQ_META | (prio ? REQ_PRIO : 0));
+
+		lock_page(page);
+
+		/* the page has been truncated by others? */
+		if (unlikely(page->mapping != mapping)) {
+			unlock_page(page);
+			put_page(page);
+			goto repeat;
+		}
+
+		/* more likely a read error */
+		if (unlikely(!PageUptodate(page))) {
+			unlock_page(page);
+			put_page(page);
+
+			page = ERR_PTR(-EIO);
+		}
+	}
+	return page;
+}
+
+static int erofs_map_blocks_flatmode(struct inode *inode,
+	struct erofs_map_blocks *map,
+	int flags)
+{
+	erofs_blk_t nblocks, lastblk;
+	u64 offset = map->m_la;
+	struct erofs_vnode *vi = EROFS_V(inode);
+
+	BUG_ON(is_inode_layout_compression(inode));
+
+	nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
+	lastblk = nblocks - is_inode_layout_inline(inode);
+
+	if (unlikely(offset >= inode->i_size)) {
+		/* leave out-of-bound access unmapped */
+		map->m_flags = 0;
+		map->m_plen = 0;
+		goto out;
+	}
+
+	/* there is no hole in flatmode */
+	map->m_flags = EROFS_MAP_MAPPED;
+
+	if (offset < blknr_to_addr(lastblk)) {
+		map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
+		map->m_plen = blknr_to_addr(lastblk) - offset;
+	} else if (is_inode_layout_inline(inode)) {
+		/* 2 - inode inline B: inode, [xattrs], inline last blk... */
+		struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+
+		map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
+			vi->xattr_isize + erofs_blkoff(map->m_la);
+		map->m_plen = inode->i_size - offset;
+
+		/* inline data should locate in one meta block */
+		BUG_ON(erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE);
+		map->m_flags |= EROFS_MAP_META;
+	} else {
+		errln("internal error @ nid: %llu (size %llu), m_la 0x%llx",
+			vi->nid, inode->i_size, map->m_la);
+		BUG();
+	}
+
+out:
+	map->m_llen = map->m_plen;
+	debugln("%s, m_la 0x%llx m_pa %llx m_len %llu",
+		__func__, map->m_la, map->m_pa, map->m_plen);
+	return 0;
+}
+
+int erofs_map_blocks(struct inode *inode,
+	struct erofs_map_blocks *map, int flags)
+{
+	if (unlikely(is_inode_layout_compression(inode)))
+		return -ENOTSUPP;
+
+	return erofs_map_blocks_flatmode(inode, map, flags);
+}
+
+static inline struct bio *erofs_read_raw_page(
+	struct bio *bio,
+	struct address_space *mapping,
+	struct page *page,
+	erofs_off_t *last_block,
+	unsigned nblocks,
+	bool ra)
+{
+	struct inode *inode = mapping->host;
+	erofs_off_t current_block = (erofs_off_t)page->index;
+	int err;
+
+	BUG_ON(!nblocks);
+
+	if (PageUptodate(page)) {
+		err = 0;
+		goto has_updated;
+	}
+
+	if (cleancache_get_page(page) == 0) {
+		err = 0;
+		SetPageUptodate(page);
+		goto has_updated;
+	}
+
+	/* note that for readpage case, bio also equals to NULL */
+	if (bio != NULL &&
+		/* not continuous */
+		*last_block + 1 != current_block) {
+submit_bio_retry:
+		__submit_bio(bio, REQ_OP_READ, 0);
+		bio = NULL;
+	}
+
+	if (bio == NULL) {
+		struct erofs_map_blocks map = {
+			.m_la = blknr_to_addr(current_block),
+		};
+
+		err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+		if (unlikely(err))
+			goto err_out;
+
+		/* zero out the holed page */
+		if (unlikely(!(map.m_flags & EROFS_MAP_MAPPED))) {
+			zero_user_segment(page, 0, PAGE_SIZE);
+			SetPageUptodate(page);
+
+			/* imply err = 0, see erofs_map_blocks */
+			goto has_updated;
+		}
+
+		/* for RAW access mode, m_plen must be equal to m_llen */
+		BUG_ON(map.m_plen != map.m_llen);
+
+		/* deal with inline page */
+		if (map.m_flags & EROFS_MAP_META) {
+			void *vsrc, *vto;
+			struct page *ipage;
+
+			BUG_ON(map.m_plen > PAGE_SIZE);
+
+			ipage = erofs_get_meta_page(inode->i_sb,
+				erofs_blknr(map.m_pa), 0);
+
+			if (IS_ERR(ipage)) {
+				err = PTR_ERR(ipage);
+				goto err_out;
+			}
+
+			vsrc = kmap_atomic(ipage);
+			vto = kmap_atomic(page);
+			memcpy(vto, vsrc + erofs_blkoff(map.m_pa), map.m_plen);
+			memset(vto + map.m_plen, 0, PAGE_SIZE - map.m_plen);
+			kunmap_atomic(vto);
+			kunmap_atomic(vsrc);
+			flush_dcache_page(page);
+
+			SetPageUptodate(page);
+			/* TODO: could we unlock the page earlier? */
+			unlock_page(ipage);
+			put_page(ipage);
+
+			/* imply err = 0, see erofs_map_blocks */
+			goto has_updated;
+		}
+
+		/* pa must be block-aligned for raw reading */
+		BUG_ON(erofs_blkoff(map.m_pa) != 0);
+
+		/* max # of continuous pages */
+		if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE))
+			nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE);
+		if (nblocks > BIO_MAX_PAGES)
+			nblocks = BIO_MAX_PAGES;
+
+		bio = prepare_bio(inode->i_sb, erofs_blknr(map.m_pa), nblocks);
+	}
+
+	err = bio_add_page(bio, page, PAGE_SIZE, 0);
+	/* out of the extent or bio is full */
+	if (err < PAGE_SIZE)
+		goto submit_bio_retry;
+
+	*last_block = current_block;
+
+	/* shift in advance in case of it followed by too many gaps */
+	if (unlikely(bio->bi_vcnt >= bio->bi_max_vecs)) {
+		/* err should reassign to 0 after submitting */
+		err = 0;
+		goto submit_bio_out;
+	}
+
+	return bio;
+
+err_out:
+	/* for sync reading, set page error immediately */
+	if (!ra) {
+		SetPageError(page);
+		ClearPageUptodate(page);
+	}
+has_updated:
+	unlock_page(page);
+
+	/* if updated manually, continuous pages has a gap */
+	if (bio != NULL)
+submit_bio_out:
+		__submit_bio(bio, REQ_OP_READ, 0);
+
+	return unlikely(err) ? ERR_PTR(err) : NULL;
+}
+
+/*
+ * since we dont have write or truncate flows, so no inode
+ * locking needs to be held at the moment.
+ */
+static int erofs_raw_access_readpage(struct file *file, struct page *page)
+{
+	erofs_off_t last_block;
+	struct bio *bio;
+
+	bio = erofs_read_raw_page(NULL, page->mapping,
+		page, &last_block, 1, false);
+
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	BUG_ON(bio != NULL);	/* since we have only one bio -- must be NULL */
+	return 0;
+}
+
+static int erofs_raw_access_readpages(struct file *filp,
+	struct address_space *mapping,
+	struct list_head *pages, unsigned nr_pages)
+{
+	erofs_off_t last_block;
+	struct bio *bio = NULL;
+	gfp_t gfp = readahead_gfp_mask(mapping);
+
+	for (; nr_pages; --nr_pages) {
+		struct page *page = list_entry(pages->prev, struct page, lru);
+
+		prefetchw(&page->flags);
+		list_del(&page->lru);
+
+		if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) {
+			bio = erofs_read_raw_page(bio, mapping, page,
+				&last_block, nr_pages, true);
+
+			/* all the page errors are ignored when readahead */
+			if (IS_ERR(bio)) {
+				pr_err("%s, readahead error at page %lu of nid %llu\n",
+					__func__, page->index,
+					EROFS_V(mapping->host)->nid);
+
+				bio = NULL;
+			}
+		}
+
+		/* pages could still be locked */
+		put_page(page);
+	}
+	BUG_ON(!list_empty(pages));
+
+	/* the rare case (end in gaps) */
+	if (unlikely(bio != NULL))
+		__submit_bio(bio, REQ_OP_READ, 0);
+	return 0;
+}
+
+/* for uncompressed (aligned) files and raw access for other files */
+const struct address_space_operations erofs_raw_access_aops = {
+	.readpage = erofs_raw_access_readpage,
+	.readpages = erofs_raw_access_readpages,
+};
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 05/25] staging: erofs: add inode operations
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (3 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 04/25] staging: erofs: add raw address_space operations Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 06/25] staging: erofs: add directory operations Gao Xiang
                     ` (21 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This adds core functions to get, read an inode.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/inode.c | 210 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 210 insertions(+)
 create mode 100644 drivers/staging/erofs/inode.c

diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
new file mode 100644
index 0000000..74e65be
--- /dev/null
+++ b/drivers/staging/erofs/inode.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/inode.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "internal.h"
+
+/* no locking */
+static int read_inode(struct inode *inode, void *data)
+{
+	struct erofs_vnode *vi = EROFS_V(inode);
+	struct erofs_inode_v1 *v1 = data;
+	const unsigned advise = le16_to_cpu(v1->i_advise);
+
+	vi->data_mapping_mode = __inode_data_mapping(advise);
+
+	if (unlikely(vi->data_mapping_mode >= EROFS_INODE_LAYOUT_MAX)) {
+		errln("unknown data mapping mode %u of nid %llu",
+			vi->data_mapping_mode, vi->nid);
+		DBG_BUGON(1);
+		return -EIO;
+	}
+
+	if (__inode_version(advise) == EROFS_INODE_LAYOUT_V2) {
+		struct erofs_inode_v2 *v2 = data;
+
+		vi->inode_isize = sizeof(struct erofs_inode_v2);
+		vi->xattr_isize = ondisk_xattr_ibody_size(v2->i_xattr_icount);
+
+		vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
+		inode->i_mode = le16_to_cpu(v2->i_mode);
+
+		i_uid_write(inode, le32_to_cpu(v2->i_uid));
+		i_gid_write(inode, le32_to_cpu(v2->i_gid));
+		set_nlink(inode, le32_to_cpu(v2->i_nlink));
+
+		/* ns timestamp */
+		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+			le64_to_cpu(v2->i_ctime);
+		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+			le32_to_cpu(v2->i_ctime_nsec);
+
+		inode->i_size = le64_to_cpu(v2->i_size);
+	} else if (__inode_version(advise) == EROFS_INODE_LAYOUT_V1) {
+		struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+
+		vi->inode_isize = sizeof(struct erofs_inode_v1);
+		vi->xattr_isize = ondisk_xattr_ibody_size(v1->i_xattr_icount);
+
+		vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
+		inode->i_mode = le16_to_cpu(v1->i_mode);
+
+		i_uid_write(inode, le16_to_cpu(v1->i_uid));
+		i_gid_write(inode, le16_to_cpu(v1->i_gid));
+		set_nlink(inode, le16_to_cpu(v1->i_nlink));
+
+		/* use build time to derive all file time */
+		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+			sbi->build_time;
+		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+			sbi->build_time_nsec;
+
+		inode->i_size = le32_to_cpu(v1->i_size);
+	} else {
+		errln("unsupported on-disk inode version %u of nid %llu",
+			__inode_version(advise), vi->nid);
+		DBG_BUGON(1);
+		return -EIO;
+	}
+
+	/* measure inode.i_blocks as the generic filesystem */
+	inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
+	return 0;
+}
+
+/*
+ * try_lock can be required since locking order is:
+ *   file data(fs_inode)
+ *        meta(bd_inode)
+ * but the majority of the callers is "iget",
+ * in that case we are pretty sure no deadlock since
+ * no data operations exist. However I tend to
+ * try_lock since it takes no much overhead and
+ * will success immediately.
+ */
+static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
+{
+	struct erofs_vnode *vi = EROFS_V(inode);
+	int mode = vi->data_mapping_mode;
+
+	DBG_BUGON(mode >= EROFS_INODE_LAYOUT_MAX);
+
+	/* should be inode inline C */
+	if (mode != EROFS_INODE_LAYOUT_INLINE)
+		return 0;
+
+	/* fast symlink (following ext4) */
+	if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
+		char *lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
+
+		if (unlikely(lnk == NULL))
+			return -ENOMEM;
+
+		m_pofs += vi->inode_isize + vi->xattr_isize;
+		BUG_ON(m_pofs + inode->i_size > PAGE_SIZE);
+
+		/* get in-page inline data */
+		memcpy(lnk, data + m_pofs, inode->i_size);
+		lnk[inode->i_size] = '\0';
+
+		inode->i_link = lnk;
+		set_inode_fast_symlink(inode);
+	}
+	return -EAGAIN;
+}
+
+static int fill_inode(struct inode *inode, int isdir)
+{
+	struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+	struct erofs_vnode *vi = EROFS_V(inode);
+	struct page *page;
+	void *data;
+	int err;
+	erofs_blk_t blkaddr;
+	unsigned ofs;
+
+	blkaddr = erofs_blknr(iloc(sbi, vi->nid));
+	ofs = erofs_blkoff(iloc(sbi, vi->nid));
+
+	debugln("%s, reading inode nid %llu at %u of blkaddr %u",
+		__func__, vi->nid, ofs, blkaddr);
+
+	page = erofs_get_meta_page(inode->i_sb, blkaddr, isdir);
+
+	if (IS_ERR(page)) {
+		errln("failed to get inode (nid: %llu) page, err %ld",
+			vi->nid, PTR_ERR(page));
+		return PTR_ERR(page);
+	}
+
+	BUG_ON(!PageUptodate(page));
+	data = page_address(page);
+
+	err = read_inode(inode, data + ofs);
+	if (!err) {
+		/* setup the new inode */
+		if (S_ISREG(inode->i_mode)) {
+			inode->i_fop = &generic_ro_fops;
+		} else if (S_ISDIR(inode->i_mode)) {
+			inode->i_op =
+				&erofs_dir_iops;
+			inode->i_fop = &erofs_dir_fops;
+		} else if (S_ISLNK(inode->i_mode)) {
+			/* by default, page_get_link is used for symlink */
+			inode->i_op =
+				&page_symlink_inode_operations;
+			inode_nohighmem(inode);
+		} else {
+			err = -EIO;
+			goto out_unlock;
+		}
+
+		if (is_inode_layout_compression(inode)) {
+			err = -ENOTSUPP;
+			goto out_unlock;
+		}
+
+		inode->i_mapping->a_ops = &erofs_raw_access_aops;
+
+		/* fill last page if inline data is available */
+		fill_inline_data(inode, data, ofs);
+	}
+
+out_unlock:
+	unlock_page(page);
+	put_page(page);
+	return err;
+}
+
+struct inode *erofs_iget(struct super_block *sb,
+	erofs_nid_t nid, bool isdir)
+{
+	struct inode *inode = iget_locked(sb, nid);
+
+	if (unlikely(inode == NULL))
+		return ERR_PTR(-ENOMEM);
+
+	if (inode->i_state & I_NEW) {
+		int err;
+		struct erofs_vnode *vi = EROFS_V(inode);
+		vi->nid = nid;
+
+		err = fill_inode(inode, isdir);
+		if (likely(!err))
+			unlock_new_inode(inode);
+		else {
+			iget_failed(inode);
+			inode = ERR_PTR(err);
+		}
+	}
+	return inode;
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 06/25] staging: erofs: add directory operations
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (4 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 05/25] staging: erofs: add inode operations Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 07/25] staging: erofs: add namei functions Gao Xiang
                     ` (20 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This adds functions for directory, mainly readdir.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/dir.c | 145 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 drivers/staging/erofs/dir.c

diff --git a/drivers/staging/erofs/dir.c b/drivers/staging/erofs/dir.c
new file mode 100644
index 0000000..be6ae3b
--- /dev/null
+++ b/drivers/staging/erofs/dir.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/dir.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "internal.h"
+
+static const unsigned char erofs_filetype_table[EROFS_FT_MAX] = {
+	[EROFS_FT_UNKNOWN]	= DT_UNKNOWN,
+	[EROFS_FT_REG_FILE]	= DT_REG,
+	[EROFS_FT_DIR]		= DT_DIR,
+	[EROFS_FT_CHRDEV]	= DT_CHR,
+	[EROFS_FT_BLKDEV]	= DT_BLK,
+	[EROFS_FT_FIFO]		= DT_FIFO,
+	[EROFS_FT_SOCK]		= DT_SOCK,
+	[EROFS_FT_SYMLINK]	= DT_LNK,
+};
+
+static int erofs_fill_dentries(struct dir_context *ctx,
+	void *dentry_blk, unsigned *ofs,
+	unsigned nameoff, unsigned maxsize)
+{
+	struct erofs_dirent *de = dentry_blk;
+	const struct erofs_dirent *end = dentry_blk + nameoff;
+
+	de = dentry_blk + *ofs;
+	while (de < end) {
+		const char *de_name;
+		int de_namelen;
+		unsigned char d_type;
+#ifdef CONFIG_EROFS_FS_DEBUG
+		unsigned dbg_namelen;
+		unsigned char dbg_namebuf[EROFS_NAME_LEN];
+#endif
+
+		if (unlikely(de->file_type < EROFS_FT_MAX))
+			d_type = erofs_filetype_table[de->file_type];
+		else
+			d_type = DT_UNKNOWN;
+
+		nameoff = le16_to_cpu(de->nameoff);
+		de_name = (char *)dentry_blk + nameoff;
+
+		de_namelen = unlikely(de + 1 >= end) ?
+			/* last directory entry */
+			strnlen(de_name, maxsize - nameoff) :
+			le16_to_cpu(de[1].nameoff) - nameoff;
+
+		/* the corrupted directory found */
+		BUG_ON(de_namelen < 0);
+
+#ifdef CONFIG_EROFS_FS_DEBUG
+		dbg_namelen = min(EROFS_NAME_LEN - 1, de_namelen);
+		memcpy(dbg_namebuf, de_name, dbg_namelen);
+		dbg_namebuf[dbg_namelen] = '\0';
+
+		debugln("%s, found de_name %s de_len %d d_type %d", __func__,
+			dbg_namebuf, de_namelen, d_type);
+#endif
+
+		if (!dir_emit(ctx, de_name, de_namelen,
+					le64_to_cpu(de->nid), d_type))
+			/* stoped by some reason */
+			return 1;
+		++de;
+		*ofs += sizeof(struct erofs_dirent);
+	}
+	*ofs = maxsize;
+	return 0;
+}
+
+static int erofs_readdir(struct file *f, struct dir_context *ctx)
+{
+	struct inode *dir = file_inode(f);
+	struct address_space *mapping = dir->i_mapping;
+	const size_t dirsize = i_size_read(dir);
+	unsigned i = ctx->pos / EROFS_BLKSIZ;
+	unsigned ofs = ctx->pos % EROFS_BLKSIZ;
+	int err = 0;
+	bool initial = true;
+
+	while (ctx->pos < dirsize) {
+		struct page *dentry_page;
+		struct erofs_dirent *de;
+		unsigned nameoff, maxsize;
+
+		dentry_page = read_mapping_page(mapping, i, NULL);
+		if (IS_ERR(dentry_page))
+			continue;
+
+		lock_page(dentry_page);
+		de = (struct erofs_dirent *)kmap(dentry_page);
+
+		nameoff = le16_to_cpu(de->nameoff);
+
+		if (unlikely(nameoff < sizeof(struct erofs_dirent) ||
+			nameoff >= PAGE_SIZE)) {
+			errln("%s, invalid de[0].nameoff %u",
+				__func__, nameoff);
+
+			err = -EIO;
+			goto skip_this;
+		}
+
+		maxsize = min_t(unsigned, dirsize - ctx->pos + ofs, PAGE_SIZE);
+
+		/* search dirents at the arbitrary position */
+		if (unlikely(initial)) {
+			initial = false;
+
+			ofs = roundup(ofs, sizeof(struct erofs_dirent));
+			if (unlikely(ofs >= nameoff))
+				goto skip_this;
+		}
+
+		err = erofs_fill_dentries(ctx, de, &ofs, nameoff, maxsize);
+skip_this:
+		kunmap(dentry_page);
+
+		unlock_page(dentry_page);
+		put_page(dentry_page);
+
+		ctx->pos = blknr_to_addr(i) + ofs;
+
+		if (unlikely(err))
+			break;
+		++i;
+		ofs = 0;
+	}
+	return err < 0 ? err : 0;
+}
+
+const struct file_operations erofs_dir_fops = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate	= erofs_readdir,
+};
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 07/25] staging: erofs: add namei functions
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (5 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 06/25] staging: erofs: add directory operations Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 08/25] staging: erofs: update Kconfig and Makefile Gao Xiang
                     ` (19 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This commit adds functions that transfer names to inodes.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/namei.c | 243 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 243 insertions(+)
 create mode 100644 drivers/staging/erofs/namei.c

diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
new file mode 100644
index 0000000..39db643
--- /dev/null
+++ b/drivers/staging/erofs/namei.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/namei.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "internal.h"
+
+/* based on the value of qn->len is accurate */
+static inline int dirnamecmp(struct qstr *qn,
+	struct qstr *qd, unsigned *matched)
+{
+	unsigned i = *matched, len = min(qn->len, qd->len);
+loop:
+	if (unlikely(i >= len)) {
+		*matched = i;
+		if (qn->len < qd->len) {
+			/*
+			 * actually (qn->len == qd->len)
+			 * when qd->name[i] == '\0'
+			 */
+			return qd->name[i] == '\0' ? 0 : -1;
+		}
+		return (qn->len > qd->len);
+	}
+
+	if (qn->name[i] != qd->name[i]) {
+		*matched = i;
+		return qn->name[i] > qd->name[i] ? 1 : -1;
+	}
+
+	++i;
+	goto loop;
+}
+
+static struct erofs_dirent *find_target_dirent(
+	struct qstr *name,
+	u8 *data, int maxsize)
+{
+	unsigned ndirents, head, back;
+	unsigned startprfx, endprfx;
+	struct erofs_dirent *const de = (struct erofs_dirent *)data;
+
+	/* make sure that maxsize is valid */
+	BUG_ON(maxsize < sizeof(struct erofs_dirent));
+
+	ndirents = le16_to_cpu(de->nameoff) / sizeof(*de);
+
+	/* corrupted dir (may be unnecessary...) */
+	BUG_ON(!ndirents);
+
+	head = 0;
+	back = ndirents - 1;
+	startprfx = endprfx = 0;
+
+	while (head <= back) {
+		unsigned mid = head + (back - head) / 2;
+		unsigned nameoff = le16_to_cpu(de[mid].nameoff);
+		unsigned matched = min(startprfx, endprfx);
+
+		struct qstr dname = QSTR_INIT(data + nameoff,
+			unlikely(mid >= ndirents - 1) ?
+				maxsize - nameoff :
+				le16_to_cpu(de[mid + 1].nameoff) - nameoff);
+
+		/* string comparison without already matched prefix */
+		int ret = dirnamecmp(name, &dname, &matched);
+
+		if (unlikely(!ret))
+			return de + mid;
+		else if (ret > 0) {
+			head = mid + 1;
+			startprfx = matched;
+		} else if (unlikely(mid < 1))	/* fix "mid" overflow */
+			break;
+		else {
+			back = mid - 1;
+			endprfx = matched;
+		}
+	}
+
+	return ERR_PTR(-ENOENT);
+}
+
+static struct page *find_target_block_classic(
+	struct inode *dir,
+	struct qstr *name, int *_diff)
+{
+	unsigned startprfx, endprfx;
+	unsigned head, back;
+	struct address_space *const mapping = dir->i_mapping;
+	struct page *candidate = ERR_PTR(-ENOENT);
+
+	startprfx = endprfx = 0;
+	head = 0;
+	back = inode_datablocks(dir) - 1;
+
+	while (head <= back) {
+		unsigned mid = head + (back - head) / 2;
+		struct page *page = read_mapping_page(mapping, mid, NULL);
+
+		if (IS_ERR(page)) {
+exact_out:
+			if (!IS_ERR(candidate)) /* valid candidate */
+				put_page(candidate);
+			return page;
+		} else {
+			int diff;
+			unsigned ndirents, matched;
+			struct qstr dname;
+			struct erofs_dirent *de = kmap_atomic(page);
+			unsigned nameoff = le16_to_cpu(de->nameoff);
+
+			ndirents = nameoff / sizeof(*de);
+
+			/* corrupted dir (should have one entry at least) */
+			BUG_ON(!ndirents || nameoff > PAGE_SIZE);
+
+			matched = min(startprfx, endprfx);
+
+			dname.name = (u8 *)de + nameoff;
+			dname.len = ndirents == 1 ?
+				/* since the rest of the last page is 0 */
+				EROFS_BLKSIZ - nameoff
+				: le16_to_cpu(de[1].nameoff) - nameoff;
+
+			/* string comparison without already matched prefix */
+			diff = dirnamecmp(name, &dname, &matched);
+			kunmap_atomic(de);
+
+			if (unlikely(!diff)) {
+				*_diff = 0;
+				goto exact_out;
+			} else if (diff > 0) {
+				head = mid + 1;
+				startprfx = matched;
+
+				if (likely(!IS_ERR(candidate)))
+					put_page(candidate);
+				candidate = page;
+			} else {
+				put_page(page);
+
+				if (unlikely(mid < 1))	/* fix "mid" overflow */
+					break;
+
+				back = mid - 1;
+				endprfx = matched;
+			}
+		}
+	}
+	*_diff = 1;
+	return candidate;
+}
+
+int erofs_namei(struct inode *dir,
+	struct qstr *name,
+	erofs_nid_t *nid, unsigned *d_type)
+{
+	int diff;
+	struct page *page;
+	u8 *data;
+	struct erofs_dirent *de;
+
+	if (unlikely(!dir->i_size))
+		return -ENOENT;
+
+	diff = 1;
+	page = find_target_block_classic(dir, name, &diff);
+
+	if (unlikely(IS_ERR(page)))
+		return PTR_ERR(page);
+
+	data = kmap_atomic(page);
+	/* the target page has been mapped */
+	de = likely(diff) ?
+		/* since the rest of the last page is 0 */
+		find_target_dirent(name, data, EROFS_BLKSIZ) :
+		(struct erofs_dirent *)data;
+
+	if (likely(!IS_ERR(de))) {
+		*nid = le64_to_cpu(de->nid);
+		*d_type = de->file_type;
+	}
+
+	kunmap_atomic(data);
+	put_page(page);
+
+	return IS_ERR(de) ? PTR_ERR(de) : 0;
+}
+
+/* NOTE: i_mutex is already held by vfs */
+static struct dentry *erofs_lookup(struct inode *dir,
+	struct dentry *dentry, unsigned int flags)
+{
+	int err;
+	erofs_nid_t nid;
+	unsigned d_type;
+	struct inode *inode;
+
+	DBG_BUGON(!d_really_is_negative(dentry));
+	/* dentry must be unhashed in lookup, no need to worry about */
+	DBG_BUGON(!d_unhashed(dentry));
+
+	/* file name exceeds fs limit */
+	if (unlikely(dentry->d_name.len > EROFS_NAME_LEN))
+		return ERR_PTR(-ENAMETOOLONG);
+
+	/* false uninitialized warnings on gcc 4.8.x */
+	err = erofs_namei(dir, &dentry->d_name, &nid, &d_type);
+
+	if (err == -ENOENT) {
+		/* negative dentry */
+		inode = NULL;
+		goto negative_out;
+	} else if (unlikely(err))
+		return ERR_PTR(err);
+
+	debugln("%s, %s (nid %llu) found, d_type %u", __func__,
+		dentry->d_name.name, nid, d_type);
+
+	inode = erofs_iget(dir->i_sb, nid, d_type == EROFS_FT_DIR);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+negative_out:
+	return d_splice_alias(inode, dentry);
+}
+
+const struct inode_operations erofs_dir_iops = {
+	.lookup = erofs_lookup,
+};
+
+const struct inode_operations erofs_dir_xattr_iops = {
+	.lookup = erofs_lookup,
+};
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 08/25] staging: erofs: update Kconfig and Makefile
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (6 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 07/25] staging: erofs: add namei functions Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 09/25] staging: erofs: introduce xattr & acl support Gao Xiang
                     ` (18 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This commit adds Makefile and Kconfig for erofs, and
updates Makefile and Kconfig files in the fs directory.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/Kconfig        |  2 ++
 drivers/staging/Makefile       |  1 +
 drivers/staging/erofs/Kconfig  | 36 ++++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/Makefile | 11 +++++++++++
 4 files changed, 50 insertions(+)
 create mode 100644 drivers/staging/erofs/Kconfig
 create mode 100644 drivers/staging/erofs/Makefile

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 75a4804..de9c95a 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -126,4 +126,6 @@ source "drivers/staging/mt7621-eth/Kconfig"
 
 source "drivers/staging/mt7621-dts/Kconfig"
 
+source "drivers/staging/erofs/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index e84959a..a33ac34 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_SOC_MT7621)	+= mt7621-dma/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-mmc/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-eth/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-dts/
+obj-$(CONFIG_EROFS_FS)		+= erofs/
diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
new file mode 100644
index 0000000..077430f
--- /dev/null
+++ b/drivers/staging/erofs/Kconfig
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config EROFS_FS
+	tristate "EROFS filesystem support"
+	depends on BLOCK
+	help
+	  EROFS(Enhanced Read-Only File System) is a lightweight
+	  read-only file system with modern designs (eg. page-sized
+	  blocks, inline xattrs/data, etc.) for scenarios which need
+	  high-performance read-only requirements, eg. firmwares in
+	  mobile phone or LIVECDs.
+
+	  It also provides VLE compression support, focusing on
+	  random read improvements, keeping relatively lower
+	  compression ratios, which is useful for high-performance
+	  devices with limited memory and ROM space.
+
+	  If unsure, say N.
+
+config EROFS_FS_DEBUG
+	bool "EROFS debugging feature"
+	depends on EROFS_FS
+	help
+	  Print EROFS debugging messages and enable more BUG_ONs
+	  which check the filesystem consistency aggressively.
+
+	  For daily use, say N.
+
+config EROFS_FS_USE_VM_MAP_RAM
+	bool "EROFS VM_MAP_RAM Support"
+	depends on EROFS_FS
+	help
+	  use vm_map_ram/vm_unmap_ram instead of vmap/vunmap.
+
+	  If you don't know what these are, say N.
+
diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
new file mode 100644
index 0000000..31e909e
--- /dev/null
+++ b/drivers/staging/erofs/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+
+EROFS_VERSION = "1.0pre1"
+
+ccflags-y += -Wall -DEROFS_VERSION=\"$(EROFS_VERSION)\"
+
+obj-$(CONFIG_EROFS_FS) += erofs.o
+# staging requirement: to be self-contained in its own directory
+ccflags-y += -I$(src)/include
+erofs-objs := super.o inode.o data.o namei.o dir.o
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 09/25] staging: erofs: introduce xattr & acl support
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (7 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 08/25] staging: erofs: update Kconfig and Makefile Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 10/25] staging: erofs: support special inode Gao Xiang
                     ` (17 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This implements xattr and acl functionalities.

Inline and shared xattrs are introduced for flexibility.
Specifically, if the same xattr occurs for many times
in a large number of inodes or the value of a xattr is so large
that it isn't suitable to be inlined, a shared xattr
kept in the xattr meta will be used instead.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Kconfig    |  37 +++
 drivers/staging/erofs/Makefile   |   1 +
 drivers/staging/erofs/inode.c    |  33 ++-
 drivers/staging/erofs/internal.h |  22 ++
 drivers/staging/erofs/namei.c    |   4 +
 drivers/staging/erofs/super.c    |  67 +++++
 drivers/staging/erofs/xattr.c    | 579 +++++++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/xattr.h    |  93 +++++++
 8 files changed, 835 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/erofs/xattr.c
 create mode 100644 drivers/staging/erofs/xattr.h

diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index 077430f..1a5ec1b 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -26,6 +26,43 @@ config EROFS_FS_DEBUG
 
 	  For daily use, say N.
 
+config EROFS_FS_XATTR
+	bool "EROFS extended attributes"
+	depends on EROFS_FS
+	default y
+	help
+	  Extended attributes are name:value pairs associated with inodes by
+	  the kernel or by users (see the attr(5) manual page, or visit
+	  <http://acl.bestbits.at/> for details).
+
+	  If unsure, say N.
+
+config EROFS_FS_POSIX_ACL
+	bool "EROFS Access Control Lists"
+	depends on EROFS_FS_XATTR
+	select FS_POSIX_ACL
+	default y
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N.
+
+config EROFS_FS_SECURITY
+	bool "EROFS Security Labels"
+	depends on EROFS_FS_XATTR
+	help
+	  Security labels provide an access control facility to support Linux
+	  Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
+	  Linux. This option enables an extended attribute handler for file
+	  security labels in the erofs filesystem, so that it requires enabling
+	  the extended attribute support in advance.
+
+	  If you are not using a security module, say N.
+
 config EROFS_FS_USE_VM_MAP_RAM
 	bool "EROFS VM_MAP_RAM Support"
 	depends on EROFS_FS
diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index 31e909e..977b7e0 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -8,4 +8,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
 # staging requirement: to be self-contained in its own directory
 ccflags-y += -I$(src)/include
 erofs-objs := super.o inode.o data.o namei.o dir.o
+erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
 
diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index 74e65be..15ed919 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -10,7 +10,7 @@
  * License.  See the file COPYING in the main directory of the Linux
  * distribution for more details.
  */
-#include "internal.h"
+#include "xattr.h"
 
 /* no locking */
 static int read_inode(struct inode *inode, void *data)
@@ -152,15 +152,26 @@ static int fill_inode(struct inode *inode, int isdir)
 	if (!err) {
 		/* setup the new inode */
 		if (S_ISREG(inode->i_mode)) {
+#ifdef CONFIG_EROFS_FS_XATTR
+			if (vi->xattr_isize)
+				inode->i_op = &erofs_generic_xattr_iops;
+#endif
 			inode->i_fop = &generic_ro_fops;
 		} else if (S_ISDIR(inode->i_mode)) {
 			inode->i_op =
+#ifdef CONFIG_EROFS_FS_XATTR
+				vi->xattr_isize ? &erofs_dir_xattr_iops :
+#endif
 				&erofs_dir_iops;
 			inode->i_fop = &erofs_dir_fops;
 		} else if (S_ISLNK(inode->i_mode)) {
 			/* by default, page_get_link is used for symlink */
 			inode->i_op =
+#ifdef CONFIG_EROFS_FS_XATTR
+				&erofs_symlink_xattr_iops,
+#else
 				&page_symlink_inode_operations;
+#endif
 			inode_nohighmem(inode);
 		} else {
 			err = -EIO;
@@ -208,3 +219,23 @@ struct inode *erofs_iget(struct super_block *sb,
 	return inode;
 }
 
+#ifdef CONFIG_EROFS_FS_XATTR
+const struct inode_operations erofs_generic_xattr_iops = {
+	.listxattr = erofs_listxattr,
+};
+#endif
+
+#ifdef CONFIG_EROFS_FS_XATTR
+const struct inode_operations erofs_symlink_xattr_iops = {
+	.get_link = page_get_link,
+	.listxattr = erofs_listxattr,
+};
+#endif
+
+#ifdef CONFIG_EROFS_FS_XATTR
+const struct inode_operations erofs_fast_symlink_xattr_iops = {
+	.get_link = simple_get_link,
+	.listxattr = erofs_listxattr,
+};
+#endif
+
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index d0992d2..8a8caf0 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -50,6 +50,9 @@
 struct erofs_sb_info {
 	u32 blocks;
 	u32 meta_blkaddr;
+#ifdef CONFIG_EROFS_FS_XATTR
+	u32 xattr_blkaddr;
+#endif
 
 	/* inode slot unit size in bit shift */
 	unsigned char islotbits;
@@ -72,6 +75,10 @@ struct erofs_sb_info {
 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
 
+/* Mount flags set via mount options or defaults */
+#define EROFS_MOUNT_XATTR_USER		0x00000010
+#define EROFS_MOUNT_POSIX_ACL		0x00000020
+
 #define clear_opt(sbi, option)	((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
 #define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
 #define test_opt(sbi, option)	((sbi)->mount_opt & EROFS_MOUNT_##option)
@@ -237,17 +244,32 @@ int erofs_namei(struct inode *dir, struct qstr *name,
 	erofs_nid_t *nid, unsigned *d_type);
 
 /* xattr.c */
+#ifdef CONFIG_EROFS_FS_XATTR
 extern const struct xattr_handler *erofs_xattr_handlers[];
+#endif
 
 /* symlink */
+#ifdef CONFIG_EROFS_FS_XATTR
+extern const struct inode_operations erofs_symlink_xattr_iops;
+extern const struct inode_operations erofs_fast_symlink_xattr_iops;
+#endif
+
 static inline void set_inode_fast_symlink(struct inode *inode)
 {
+#ifdef CONFIG_EROFS_FS_XATTR
+	inode->i_op = &erofs_fast_symlink_xattr_iops;
+#else
 	inode->i_op = &simple_symlink_inode_operations;
+#endif
 }
 
 static inline bool is_inode_fast_symlink(struct inode *inode)
 {
+#ifdef CONFIG_EROFS_FS_XATTR
+	return inode->i_op == &erofs_fast_symlink_xattr_iops;
+#else
 	return inode->i_op == &simple_symlink_inode_operations;
+#endif
 }
 
 static inline void *erofs_vmap(struct page **pages, unsigned int count)
diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
index 39db643..989876b 100644
--- a/drivers/staging/erofs/namei.c
+++ b/drivers/staging/erofs/namei.c
@@ -11,6 +11,7 @@
  * distribution for more details.
  */
 #include "internal.h"
+#include "xattr.h"
 
 /* based on the value of qn->len is accurate */
 static inline int dirnamecmp(struct qstr *qn,
@@ -239,5 +240,8 @@ static struct dentry *erofs_lookup(struct inode *dir,
 
 const struct inode_operations erofs_dir_xattr_iops = {
 	.lookup = erofs_lookup,
+#ifdef CONFIG_EROFS_FS_XATTR
+	.listxattr = erofs_listxattr,
+#endif
 };
 
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 98ae03d..4a8a266 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -14,6 +14,7 @@
 #include <linux/buffer_head.h>
 #include <linux/statfs.h>
 #include <linux/parser.h>
+#include <linux/seq_file.h>
 #include "internal.h"
 
 static struct kmem_cache *erofs_inode_cachep __read_mostly;
@@ -107,6 +108,9 @@ static int superblock_read(struct super_block *sb)
 
 	sbi->blocks = le32_to_cpu(layout->blocks);
 	sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
+#ifdef CONFIG_EROFS_FS_XATTR
+	sbi->xattr_blkaddr = le32_to_cpu(layout->xattr_blkaddr);
+#endif
 	sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1;
 
 	sbi->root_nid = le16_to_cpu(layout->root_nid);
@@ -127,13 +131,28 @@ static int superblock_read(struct super_block *sb)
 
 static void default_options(struct erofs_sb_info *sbi)
 {
+#ifdef CONFIG_EROFS_FS_XATTR
+	set_opt(sbi, XATTR_USER);
+#endif
+
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+	set_opt(sbi, POSIX_ACL);
+#endif
 }
 
 enum {
+	Opt_user_xattr,
+	Opt_nouser_xattr,
+	Opt_acl,
+	Opt_noacl,
 	Opt_err
 };
 
 static match_table_t erofs_tokens = {
+	{Opt_user_xattr, "user_xattr"},
+	{Opt_nouser_xattr, "nouser_xattr"},
+	{Opt_acl, "acl"},
+	{Opt_noacl, "noacl"},
 	{Opt_err, NULL}
 };
 
@@ -155,6 +174,36 @@ static int parse_options(struct super_block *sb, char *options)
 		token = match_token(p, erofs_tokens, args);
 
 		switch (token) {
+#ifdef CONFIG_EROFS_FS_XATTR
+		case Opt_user_xattr:
+			set_opt(EROFS_SB(sb), XATTR_USER);
+			break;
+		case Opt_nouser_xattr:
+			clear_opt(EROFS_SB(sb), XATTR_USER);
+			break;
+#else
+		case Opt_user_xattr:
+			infoln("user_xattr options not supported");
+			break;
+		case Opt_nouser_xattr:
+			infoln("nouser_xattr options not supported");
+			break;
+#endif
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+		case Opt_acl:
+			set_opt(EROFS_SB(sb), POSIX_ACL);
+			break;
+		case Opt_noacl:
+			clear_opt(EROFS_SB(sb), POSIX_ACL);
+			break;
+#else
+		case Opt_acl:
+			infoln("acl options not supported");
+			break;
+		case Opt_noacl:
+			infoln("noacl options not supported");
+			break;
+#endif
 		default:
 			errln("Unrecognized mount option \"%s\" "
 					"or missing value", p);
@@ -197,6 +246,10 @@ static int erofs_read_super(struct super_block *sb,
 
 	sb->s_op = &erofs_sops;
 
+#ifdef CONFIG_EROFS_FS_XATTR
+	sb->s_xattr = erofs_xattr_handlers;
+#endif
+
 	/* set erofs default mount options */
 	default_options(sbi);
 
@@ -386,6 +439,20 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 {
+	struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
+
+#ifdef CONFIG_EROFS_FS_XATTR
+	if (test_opt(sbi, XATTR_USER))
+		seq_puts(seq, ",user_xattr");
+	else
+		seq_puts(seq, ",nouser_xattr");
+#endif
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+	if (test_opt(sbi, POSIX_ACL))
+		seq_puts(seq, ",acl");
+	else
+		seq_puts(seq, ",noacl");
+#endif
 	return 0;
 }
 
diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
new file mode 100644
index 0000000..b74b314
--- /dev/null
+++ b/drivers/staging/erofs/xattr.c
@@ -0,0 +1,579 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/xattr.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include <linux/security.h>
+#include "xattr.h"
+
+struct xattr_iter {
+	struct super_block *sb;
+	struct page *page;
+	void *kaddr;
+
+	erofs_blk_t blkaddr;
+	unsigned ofs;
+};
+
+static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
+{
+	/* only init_inode_xattrs use non-atomic once */
+	if (unlikely(!atomic))
+		kunmap(it->page);
+	else
+		kunmap_atomic(it->kaddr);
+	unlock_page(it->page);
+	put_page(it->page);
+}
+
+static void init_inode_xattrs(struct inode *inode)
+{
+	struct xattr_iter it;
+	unsigned i;
+	struct erofs_xattr_ibody_header *ih;
+	struct erofs_sb_info *sbi;
+	struct erofs_vnode *vi;
+	bool atomic_map;
+
+	if (likely(inode_has_inited_xattr(inode)))
+		return;
+
+	vi = EROFS_V(inode);
+	BUG_ON(!vi->xattr_isize);
+
+	sbi = EROFS_I_SB(inode);
+	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
+	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
+
+	it.page = erofs_get_inline_page(inode, it.blkaddr);
+	BUG_ON(IS_ERR(it.page));
+
+	/* read in shared xattr array (non-atomic, see kmalloc below) */
+	it.kaddr = kmap(it.page);
+	atomic_map = false;
+
+	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
+
+	vi->xattr_shared_count = ih->h_shared_count;
+	vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
+		vi->xattr_shared_count, sizeof(unsigned),
+		GFP_KERNEL | __GFP_NOFAIL);
+
+	/* let's skip ibody header */
+	it.ofs += sizeof(struct erofs_xattr_ibody_header);
+
+	for (i = 0; i < vi->xattr_shared_count; ++i) {
+		if (unlikely(it.ofs >= EROFS_BLKSIZ)) {
+			/* cannot be unaligned */
+			BUG_ON(it.ofs != EROFS_BLKSIZ);
+			xattr_iter_end(&it, atomic_map);
+
+			it.page = erofs_get_meta_page(inode->i_sb,
+				++it.blkaddr, S_ISDIR(inode->i_mode));
+			BUG_ON(IS_ERR(it.page));
+
+			it.kaddr = kmap_atomic(it.page);
+			atomic_map = true;
+			it.ofs = 0;
+		}
+		vi->xattr_shared_xattrs[i] =
+			le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs));
+		it.ofs += sizeof(__le32);
+	}
+	xattr_iter_end(&it, atomic_map);
+
+	inode_set_inited_xattr(inode);
+}
+
+struct xattr_iter_handlers {
+	int (*entry)(struct xattr_iter *, struct erofs_xattr_entry *);
+	int (*name)(struct xattr_iter *, unsigned, char *, unsigned);
+	int (*alloc_buffer)(struct xattr_iter *, unsigned);
+	void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
+};
+
+static void xattr_iter_fixup(struct xattr_iter *it)
+{
+	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
+		xattr_iter_end(it, true);
+
+		it->blkaddr += erofs_blknr(it->ofs);
+		it->page = erofs_get_meta_page(it->sb, it->blkaddr, false);
+		BUG_ON(IS_ERR(it->page));
+
+		it->kaddr = kmap_atomic(it->page);
+		it->ofs = erofs_blkoff(it->ofs);
+	}
+}
+
+static int inline_xattr_iter_begin(struct xattr_iter *it,
+	struct inode *inode)
+{
+	struct erofs_vnode *const vi = EROFS_V(inode);
+	struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
+	unsigned xattr_header_sz, inline_xattr_ofs;
+
+	xattr_header_sz = inlinexattr_header_size(inode);
+	if (unlikely(xattr_header_sz >= vi->xattr_isize)) {
+		BUG_ON(xattr_header_sz > vi->xattr_isize);
+		return -ENOATTR;
+	}
+
+	inline_xattr_ofs = vi->inode_isize + xattr_header_sz;
+
+	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
+	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
+
+	it->page = erofs_get_inline_page(inode, it->blkaddr);
+	BUG_ON(IS_ERR(it->page));
+	it->kaddr = kmap_atomic(it->page);
+
+	return vi->xattr_isize - xattr_header_sz;
+}
+
+static int xattr_foreach(struct xattr_iter *it,
+	struct xattr_iter_handlers *op, unsigned *tlimit)
+{
+	struct erofs_xattr_entry entry;
+	unsigned value_sz, processed, slice;
+	int err;
+
+	/* 0. fixup blkaddr, ofs, ipage */
+	xattr_iter_fixup(it);
+
+	/*
+	 * 1. read xattr entry to the memory,
+	 *    since we do EROFS_XATTR_ALIGN
+	 *    therefore entry should be in the page
+	 */
+	entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
+	if (tlimit != NULL) {
+		unsigned entry_sz = EROFS_XATTR_ENTRY_SIZE(&entry);
+
+		BUG_ON(*tlimit < entry_sz);
+		*tlimit -= entry_sz;
+	}
+
+	it->ofs += sizeof(struct erofs_xattr_entry);
+	value_sz = le16_to_cpu(entry.e_value_size);
+
+	/* handle entry */
+	err = op->entry(it, &entry);
+	if (err) {
+		it->ofs += entry.e_name_len + value_sz;
+		goto out;
+	}
+
+	/* 2. handle xattr name (ofs will finally be at the end of name) */
+	processed = 0;
+
+	while (processed < entry.e_name_len) {
+		if (it->ofs >= EROFS_BLKSIZ) {
+			BUG_ON(it->ofs > EROFS_BLKSIZ);
+
+			xattr_iter_fixup(it);
+			it->ofs = 0;
+		}
+
+		slice = min_t(unsigned, PAGE_SIZE - it->ofs,
+			entry.e_name_len - processed);
+
+		/* handle name */
+		err = op->name(it, processed, it->kaddr + it->ofs, slice);
+		if (err) {
+			it->ofs += entry.e_name_len - processed + value_sz;
+			goto out;
+		}
+
+		it->ofs += slice;
+		processed += slice;
+	}
+
+	/* 3. handle xattr value */
+	processed = 0;
+
+	if (op->alloc_buffer != NULL) {
+		err = op->alloc_buffer(it, value_sz);
+		if (err) {
+			it->ofs += value_sz;
+			goto out;
+		}
+	}
+
+	while (processed < value_sz) {
+		if (it->ofs >= EROFS_BLKSIZ) {
+			BUG_ON(it->ofs > EROFS_BLKSIZ);
+			xattr_iter_fixup(it);
+			it->ofs = 0;
+		}
+
+		slice = min_t(unsigned, PAGE_SIZE - it->ofs,
+			value_sz - processed);
+		op->value(it, processed, it->kaddr + it->ofs, slice);
+		it->ofs += slice;
+		processed += slice;
+	}
+
+out:
+	/* we assume that ofs is aligned with 4 bytes */
+	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
+	return err;
+}
+
+struct getxattr_iter {
+	struct xattr_iter it;
+
+	char *buffer;
+	int buffer_size, index;
+	struct qstr name;
+};
+
+static int xattr_entrymatch(struct xattr_iter *_it,
+	struct erofs_xattr_entry *entry)
+{
+	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
+
+	return (it->index != entry->e_name_index ||
+		it->name.len != entry->e_name_len) ? -ENOATTR : 0;
+}
+
+static int xattr_namematch(struct xattr_iter *_it,
+	unsigned processed, char *buf, unsigned len)
+{
+	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
+
+	return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0;
+}
+
+static int xattr_checkbuffer(struct xattr_iter *_it,
+	unsigned value_sz)
+{
+	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
+	int err = it->buffer_size < value_sz ? -ERANGE : 0;
+
+	it->buffer_size = value_sz;
+	return it->buffer == NULL ? 1 : err;
+}
+
+static void xattr_copyvalue(struct xattr_iter *_it,
+	unsigned processed, char *buf, unsigned len)
+{
+	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
+
+	memcpy(it->buffer + processed, buf, len);
+}
+
+static struct xattr_iter_handlers find_xattr_handlers = {
+	.entry = xattr_entrymatch,
+	.name = xattr_namematch,
+	.alloc_buffer = xattr_checkbuffer,
+	.value = xattr_copyvalue
+};
+
+static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
+{
+	int ret;
+	unsigned remaining;
+
+	ret = inline_xattr_iter_begin(&it->it, inode);
+	if (ret < 0)
+		return ret;
+
+	remaining = ret;
+	while (remaining) {
+		if ((ret = xattr_foreach(&it->it,
+			&find_xattr_handlers, &remaining)) >= 0)
+			break;
+	}
+	xattr_iter_end(&it->it, true);
+
+	return ret < 0 ? ret : it->buffer_size;
+}
+
+static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
+{
+	struct erofs_vnode *const vi = EROFS_V(inode);
+	struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
+	unsigned i;
+	int ret = -ENOATTR;
+
+	for (i = 0; i < vi->xattr_shared_count; ++i) {
+		erofs_blk_t blkaddr =
+			xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
+
+		it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
+
+		if (!i || blkaddr != it->it.blkaddr) {
+			if (i)
+				xattr_iter_end(&it->it, true);
+
+			it->it.page = erofs_get_meta_page(inode->i_sb,
+				blkaddr, false);
+			BUG_ON(IS_ERR(it->it.page));
+			it->it.kaddr = kmap_atomic(it->it.page);
+			it->it.blkaddr = blkaddr;
+		}
+
+		if ((ret = xattr_foreach(&it->it,
+			&find_xattr_handlers, NULL)) >= 0)
+			break;
+	}
+	if (vi->xattr_shared_count)
+		xattr_iter_end(&it->it, true);
+
+	return ret < 0 ? ret : it->buffer_size;
+}
+
+static bool erofs_xattr_user_list(struct dentry *dentry)
+{
+	return test_opt(EROFS_SB(dentry->d_sb), XATTR_USER);
+}
+
+static bool erofs_xattr_trusted_list(struct dentry *dentry)
+{
+	return capable(CAP_SYS_ADMIN);
+}
+
+int erofs_getxattr(struct inode *inode, int index,
+	const char *name,
+	void *buffer, size_t buffer_size)
+{
+	int ret;
+	struct getxattr_iter it;
+
+	if (unlikely(name == NULL))
+		return -EINVAL;
+
+	init_inode_xattrs(inode);
+
+	it.index = index;
+
+	it.name.len = strlen(name);
+	if (it.name.len > EROFS_NAME_LEN)
+		return -ERANGE;
+	it.name.name = name;
+
+	it.buffer = buffer;
+	it.buffer_size = buffer_size;
+
+	it.it.sb = inode->i_sb;
+	ret = inline_getxattr(inode, &it);
+	if (ret == -ENOATTR)
+		ret = shared_getxattr(inode, &it);
+	return ret;
+}
+
+static int erofs_xattr_generic_get(const struct xattr_handler *handler,
+		struct dentry *unused, struct inode *inode,
+		const char *name, void *buffer, size_t size)
+{
+	struct erofs_vnode *const vi = EROFS_V(inode);
+	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
+
+	switch (handler->flags) {
+	case EROFS_XATTR_INDEX_USER:
+		if (!test_opt(sbi, XATTR_USER))
+			return -EOPNOTSUPP;
+		break;
+	case EROFS_XATTR_INDEX_TRUSTED:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		break;
+	case EROFS_XATTR_INDEX_SECURITY:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (!vi->xattr_isize)
+		return -ENOATTR;
+
+	return erofs_getxattr(inode, handler->flags, name, buffer, size);
+}
+
+const struct xattr_handler erofs_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.flags	= EROFS_XATTR_INDEX_USER,
+	.list	= erofs_xattr_user_list,
+	.get	= erofs_xattr_generic_get,
+};
+
+const struct xattr_handler erofs_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.flags	= EROFS_XATTR_INDEX_TRUSTED,
+	.list	= erofs_xattr_trusted_list,
+	.get	= erofs_xattr_generic_get,
+};
+
+#ifdef CONFIG_EROFS_FS_SECURITY
+const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.flags	= EROFS_XATTR_INDEX_SECURITY,
+	.get	= erofs_xattr_generic_get,
+};
+#endif
+
+#ifdef CONFIG_EROFS_FS_XATTR
+const struct xattr_handler *erofs_xattr_handlers[] = {
+	&erofs_xattr_user_handler,
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+#endif
+	&erofs_xattr_trusted_handler,
+#ifdef CONFIG_EROFS_FS_SECURITY
+	&erofs_xattr_security_handler,
+#endif
+	NULL,
+};
+#endif
+
+struct listxattr_iter {
+	struct xattr_iter it;
+
+	struct dentry *dentry;
+	char *buffer;
+	int buffer_size, buffer_ofs;
+};
+
+static int xattr_entrylist(struct xattr_iter *_it,
+	struct erofs_xattr_entry *entry)
+{
+	struct listxattr_iter *it =
+		container_of(_it, struct listxattr_iter, it);
+	unsigned prefix_len;
+	const char *prefix;
+
+	const struct xattr_handler *h =
+		erofs_xattr_handler(entry->e_name_index);
+
+	if (h == NULL || (h->list != NULL && !h->list(it->dentry)))
+		return 1;
+
+	/* Note that at least one of 'prefix' and 'name' should be non-NULL */
+	prefix = h->prefix != NULL ? h->prefix : h->name;
+	prefix_len = strlen(prefix);
+
+	if (it->buffer == NULL) {
+		it->buffer_ofs += prefix_len + entry->e_name_len + 1;
+		return 1;
+	}
+
+	if (it->buffer_ofs + prefix_len
+		+ entry->e_name_len + 1 > it->buffer_size)
+		return -ERANGE;
+
+	memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
+	it->buffer_ofs += prefix_len;
+	return 0;
+}
+
+static int xattr_namelist(struct xattr_iter *_it,
+	unsigned processed, char *buf, unsigned len)
+{
+	struct listxattr_iter *it =
+		container_of(_it, struct listxattr_iter, it);
+
+	memcpy(it->buffer + it->buffer_ofs, buf, len);
+	it->buffer_ofs += len;
+	return 0;
+}
+
+static int xattr_skipvalue(struct xattr_iter *_it,
+	unsigned value_sz)
+{
+	struct listxattr_iter *it =
+		container_of(_it, struct listxattr_iter, it);
+
+	it->buffer[it->buffer_ofs++] = '\0';
+	return 1;
+}
+
+static struct xattr_iter_handlers list_xattr_handlers = {
+	.entry = xattr_entrylist,
+	.name = xattr_namelist,
+	.alloc_buffer = xattr_skipvalue,
+	.value = NULL
+};
+
+static int inline_listxattr(struct listxattr_iter *it)
+{
+	int ret;
+	unsigned remaining;
+
+	ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
+	if (ret < 0)
+		return ret;
+
+	remaining = ret;
+	while (remaining) {
+		if ((ret = xattr_foreach(&it->it,
+			&list_xattr_handlers, &remaining)) < 0)
+			break;
+	}
+	xattr_iter_end(&it->it, true);
+	return ret < 0 ? ret : it->buffer_ofs;
+}
+
+static int shared_listxattr(struct listxattr_iter *it)
+{
+	struct inode *const inode = d_inode(it->dentry);
+	struct erofs_vnode *const vi = EROFS_V(inode);
+	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
+	unsigned i;
+	int ret = 0;
+
+	for (i = 0; i < vi->xattr_shared_count; ++i) {
+		erofs_blk_t blkaddr =
+			xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
+
+		it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
+		if (!i || blkaddr != it->it.blkaddr) {
+			if (i)
+				xattr_iter_end(&it->it, true);
+
+			it->it.page = erofs_get_meta_page(inode->i_sb,
+				blkaddr, false);
+			BUG_ON(IS_ERR(it->it.page));
+			it->it.kaddr = kmap_atomic(it->it.page);
+			it->it.blkaddr = blkaddr;
+		}
+
+		if ((ret = xattr_foreach(&it->it,
+			&list_xattr_handlers, NULL)) < 0)
+			break;
+	}
+	if (vi->xattr_shared_count)
+		xattr_iter_end(&it->it, true);
+
+	return ret < 0 ? ret : it->buffer_ofs;
+}
+
+ssize_t erofs_listxattr(struct dentry *dentry,
+	char *buffer, size_t buffer_size)
+{
+	int ret;
+	struct listxattr_iter it;
+
+	init_inode_xattrs(d_inode(dentry));
+
+	it.dentry = dentry;
+	it.buffer = buffer;
+	it.buffer_size = buffer_size;
+	it.buffer_ofs = 0;
+
+	it.it.sb = dentry->d_sb;
+
+	ret = inline_listxattr(&it);
+	if (ret < 0 && ret != -ENOATTR)
+		return ret;
+	return shared_listxattr(&it);
+}
+
diff --git a/drivers/staging/erofs/xattr.h b/drivers/staging/erofs/xattr.h
new file mode 100644
index 0000000..0c73792
--- /dev/null
+++ b/drivers/staging/erofs/xattr.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/drivers/staging/erofs/xattr.h
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#ifndef __EROFS_XATTR_H
+#define __EROFS_XATTR_H
+
+#include "internal.h"
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+/* Attribute not found */
+#define ENOATTR         ENODATA
+
+static inline unsigned inlinexattr_header_size(struct inode *inode)
+{
+	return sizeof(struct erofs_xattr_ibody_header)
+		+ sizeof(u32) * EROFS_V(inode)->xattr_shared_count;
+}
+
+static inline erofs_blk_t
+xattrblock_addr(struct erofs_sb_info *sbi, unsigned xattr_id)
+{
+#ifdef CONFIG_EROFS_FS_XATTR
+	return sbi->xattr_blkaddr +
+		xattr_id * sizeof(__u32) / EROFS_BLKSIZ;
+#else
+	return 0;
+#endif
+}
+
+static inline unsigned
+xattrblock_offset(struct erofs_sb_info *sbi, unsigned xattr_id)
+{
+	return (xattr_id * sizeof(__u32)) % EROFS_BLKSIZ;
+}
+
+extern const struct xattr_handler erofs_xattr_user_handler;
+extern const struct xattr_handler erofs_xattr_trusted_handler;
+#ifdef CONFIG_EROFS_FS_SECURITY
+extern const struct xattr_handler erofs_xattr_security_handler;
+#endif
+
+static inline const struct xattr_handler *erofs_xattr_handler(unsigned index)
+{
+static const struct xattr_handler *xattr_handler_map[] = {
+	[EROFS_XATTR_INDEX_USER] = &erofs_xattr_user_handler,
+#ifdef CONFIG_EROFS_FS_POSIX_ACL
+	[EROFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
+	[EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT] =
+		&posix_acl_default_xattr_handler,
+#endif
+	[EROFS_XATTR_INDEX_TRUSTED] = &erofs_xattr_trusted_handler,
+#ifdef CONFIG_EROFS_FS_SECURITY
+	[EROFS_XATTR_INDEX_SECURITY] = &erofs_xattr_security_handler,
+#endif
+};
+	return index && index < ARRAY_SIZE(xattr_handler_map) ?
+		xattr_handler_map[index] : NULL;
+}
+
+#ifdef CONFIG_EROFS_FS_XATTR
+
+extern const struct inode_operations erofs_generic_xattr_iops;
+extern const struct inode_operations erofs_dir_xattr_iops;
+
+int erofs_getxattr(struct inode *, int, const char *, void *, size_t);
+ssize_t erofs_listxattr(struct dentry *, char *, size_t);
+#else
+static int __maybe_unused erofs_getxattr(struct inode *inode, int index,
+	const char *name,
+	void *buffer, size_t buffer_size)
+{
+	return -ENOTSUPP;
+}
+
+static ssize_t __maybe_unused erofs_listxattr(struct dentry *dentry,
+	char *buffer, size_t buffer_size)
+{
+	return -ENOTSUPP;
+}
+#endif
+
+#endif
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 10/25] staging: erofs: support special inode
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (8 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 09/25] staging: erofs: introduce xattr & acl support Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 11/25] staging: erofs: introduce error injection infrastructure Gao Xiang
                     ` (16 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao

From: Chao Yu <yuchao0@huawei.com>

This patch adds to support special inode, such as block dev, char,
socket, pipe inode.

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 drivers/staging/erofs/inode.c    | 36 ++++++++++++++++++++++++++++++++++--
 drivers/staging/erofs/internal.h |  1 +
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index 15ed919..c011811 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -34,8 +34,18 @@ static int read_inode(struct inode *inode, void *data)
 		vi->inode_isize = sizeof(struct erofs_inode_v2);
 		vi->xattr_isize = ondisk_xattr_ibody_size(v2->i_xattr_icount);
 
-		vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
 		inode->i_mode = le16_to_cpu(v2->i_mode);
+		if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+						S_ISLNK(inode->i_mode)) {
+			vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
+		} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(v2->i_u.rdev));
+		} else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+			inode->i_rdev = 0;
+		} else {
+			return -EIO;
+		}
 
 		i_uid_write(inode, le32_to_cpu(v2->i_uid));
 		i_gid_write(inode, le32_to_cpu(v2->i_gid));
@@ -54,8 +64,18 @@ static int read_inode(struct inode *inode, void *data)
 		vi->inode_isize = sizeof(struct erofs_inode_v1);
 		vi->xattr_isize = ondisk_xattr_ibody_size(v1->i_xattr_icount);
 
-		vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
 		inode->i_mode = le16_to_cpu(v1->i_mode);
+		if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+						S_ISLNK(inode->i_mode)) {
+			vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
+		} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(v1->i_u.rdev));
+		} else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+			inode->i_rdev = 0;
+		} else {
+			return -EIO;
+		}
 
 		i_uid_write(inode, le16_to_cpu(v1->i_uid));
 		i_gid_write(inode, le16_to_cpu(v1->i_gid));
@@ -173,6 +193,12 @@ static int fill_inode(struct inode *inode, int isdir)
 				&page_symlink_inode_operations;
 #endif
 			inode_nohighmem(inode);
+		} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+#ifdef CONFIG_EROFS_FS_XATTR
+			inode->i_op = &erofs_special_inode_operations;
+#endif
+			init_special_inode(inode, inode->i_mode, inode->i_rdev);
 		} else {
 			err = -EIO;
 			goto out_unlock;
@@ -232,6 +258,12 @@ struct inode *erofs_iget(struct super_block *sb,
 };
 #endif
 
+const struct inode_operations erofs_special_inode_operations = {
+#ifdef CONFIG_EROFS_FS_XATTR
+	.listxattr = erofs_listxattr,
+#endif
+};
+
 #ifdef CONFIG_EROFS_FS_XATTR
 const struct inode_operations erofs_fast_symlink_xattr_iops = {
 	.get_link = simple_get_link,
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 8a8caf0..5862705 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -252,6 +252,7 @@ int erofs_namei(struct inode *dir, struct qstr *name,
 #ifdef CONFIG_EROFS_FS_XATTR
 extern const struct inode_operations erofs_symlink_xattr_iops;
 extern const struct inode_operations erofs_fast_symlink_xattr_iops;
+extern const struct inode_operations erofs_special_inode_operations;
 #endif
 
 static inline void set_inode_fast_symlink(struct inode *inode)
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 11/25] staging: erofs: introduce error injection infrastructure
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (9 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 10/25] staging: erofs: support special inode Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 12/25] staging: erofs: support tracepoint Gao Xiang
                     ` (15 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao

From: Chao Yu <yuchao0@huawei.com>

This patch introduces error injection infrastructure, with it, we can
inject error in any kernel exported common functions which erofs used,
so that it can force erofs running into error paths, it turns out that
tests can cover real rare paths more easily to find bugs.

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 drivers/staging/erofs/Kconfig    |  6 +++++
 drivers/staging/erofs/inode.c    |  3 ++-
 drivers/staging/erofs/internal.h | 57 ++++++++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/super.c    | 38 +++++++++++++++++++++++++++
 4 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index 1a5ec1b..edda055 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -71,3 +71,9 @@ config EROFS_FS_USE_VM_MAP_RAM
 
 	  If you don't know what these are, say N.
 
+config EROFS_FAULT_INJECTION
+	bool "EROFS fault injection facility"
+	depends on EROFS_FS
+	help
+	  Test EROFS to inject faults such as ENOMEM, EIO, and so on.
+	  If unsure, say N.
diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index c011811..a6d3e12 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -113,6 +113,7 @@ static int read_inode(struct inode *inode, void *data)
 static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
 {
 	struct erofs_vnode *vi = EROFS_V(inode);
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
 	int mode = vi->data_mapping_mode;
 
 	DBG_BUGON(mode >= EROFS_INODE_LAYOUT_MAX);
@@ -123,7 +124,7 @@ static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
 
 	/* fast symlink (following ext4) */
 	if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
-		char *lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
+		char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL);
 
 		if (unlikely(lnk == NULL))
 			return -ENOMEM;
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 5862705..ca22486 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -42,6 +42,22 @@
 #define DBG_BUGON(...)          ((void)0)
 #endif
 
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+enum {
+	FAULT_KMALLOC,
+	FAULT_MAX,
+};
+
+extern char *erofs_fault_name[FAULT_MAX];
+#define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
+
+struct erofs_fault_info {
+	atomic_t inject_ops;
+	unsigned int inject_rate;
+	unsigned int inject_type;
+};
+#endif
+
 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
 #define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
 
@@ -70,14 +86,55 @@ struct erofs_sb_info {
 	char *dev_name;
 
 	unsigned int mount_opt;
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+	struct erofs_fault_info fault_info;	/* For fault injection */
+#endif
 };
 
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+#define erofs_show_injection_info(type)					\
+	infoln("inject %s in %s of %pS", erofs_fault_name[type],        \
+		__func__, __builtin_return_address(0))
+
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+	struct erofs_fault_info *ffi = &sbi->fault_info;
+
+	if (!ffi->inject_rate)
+		return false;
+
+	if (!IS_FAULT_SET(ffi, type))
+		return false;
+
+	atomic_inc(&ffi->inject_ops);
+	if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
+		atomic_set(&ffi->inject_ops, 0);
+		return true;
+	}
+	return false;
+}
+#endif
+
+static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
+					size_t size, gfp_t flags)
+{
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+	if (time_to_inject(sbi, FAULT_KMALLOC)) {
+		erofs_show_injection_info(FAULT_KMALLOC);
+		return NULL;
+	}
+#endif
+	return kmalloc(size, flags);
+}
+
 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
 
 /* Mount flags set via mount options or defaults */
 #define EROFS_MOUNT_XATTR_USER		0x00000010
 #define EROFS_MOUNT_POSIX_ACL		0x00000020
+#define EROFS_MOUNT_FAULT_INJECTION	0x00000040
 
 #define clear_opt(sbi, option)	((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
 #define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 4a8a266..701425f 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -129,6 +129,26 @@ static int superblock_read(struct super_block *sb)
 	return ret;
 }
 
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+char *erofs_fault_name[FAULT_MAX] = {
+	[FAULT_KMALLOC]		= "kmalloc",
+};
+
+static void erofs_build_fault_attr(struct erofs_sb_info *sbi,
+						unsigned int rate)
+{
+	struct erofs_fault_info *ffi = &sbi->fault_info;
+
+	if (rate) {
+		atomic_set(&ffi->inject_ops, 0);
+		ffi->inject_rate = rate;
+		ffi->inject_type = (1 << FAULT_MAX) - 1;
+	} else {
+		memset(ffi, 0, sizeof(struct erofs_fault_info));
+	}
+}
+#endif
+
 static void default_options(struct erofs_sb_info *sbi)
 {
 #ifdef CONFIG_EROFS_FS_XATTR
@@ -145,6 +165,7 @@ enum {
 	Opt_nouser_xattr,
 	Opt_acl,
 	Opt_noacl,
+	Opt_fault_injection,
 	Opt_err
 };
 
@@ -153,6 +174,7 @@ enum {
 	{Opt_nouser_xattr, "nouser_xattr"},
 	{Opt_acl, "acl"},
 	{Opt_noacl, "noacl"},
+	{Opt_fault_injection, "fault_injection=%u"},
 	{Opt_err, NULL}
 };
 
@@ -160,6 +182,7 @@ static int parse_options(struct super_block *sb, char *options)
 {
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
+	int arg = 0;
 
 	if (!options)
 		return 0;
@@ -204,6 +227,16 @@ static int parse_options(struct super_block *sb, char *options)
 			infoln("noacl options not supported");
 			break;
 #endif
+		case Opt_fault_injection:
+			if (args->from && match_int(args, &arg))
+				return -EINVAL;
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+			erofs_build_fault_attr(EROFS_SB(sb), arg);
+			set_opt(EROFS_SB(sb), FAULT_INJECTION);
+#else
+			infoln("FAULT_INJECTION was not selected");
+#endif
+			break;
 		default:
 			errln("Unrecognized mount option \"%s\" "
 					"or missing value", p);
@@ -453,6 +486,11 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 	else
 		seq_puts(seq, ",noacl");
 #endif
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+	if (test_opt(sbi, FAULT_INJECTION))
+		seq_printf(seq, ",fault_injection=%u",
+				sbi->fault_info.inject_rate);
+#endif
 	return 0;
 }
 
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 12/25] staging: erofs: support tracepoint
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (10 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 11/25] staging: erofs: introduce error injection infrastructure Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 13/25] staging: erofs: <linux/tagptr.h>: introduce tagged pointer Gao Xiang
                     ` (14 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao

From: Chao Yu <yuchao0@huawei.com>

Add basic tracepoints for ->readpage{,s}, ->lookup,
->destroy_inode, fill_inode and map_blocks.

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 drivers/staging/erofs/data.c                       |  13 +-
 drivers/staging/erofs/include/trace/events/erofs.h | 240 +++++++++++++++++++++
 drivers/staging/erofs/inode.c                      |   4 +
 drivers/staging/erofs/namei.c                      |   4 +
 drivers/staging/erofs/super.c                      |   3 +
 5 files changed, 261 insertions(+), 3 deletions(-)
 create mode 100644 drivers/staging/erofs/include/trace/events/erofs.h

diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index 4ddb5c0..47d1787 100644
--- a/drivers/staging/erofs/data.c
+++ b/drivers/staging/erofs/data.c
@@ -13,6 +13,8 @@
 #include "internal.h"
 #include <linux/prefetch.h>
 
+#include <trace/events/erofs.h>
+
 static inline void read_endio(struct bio *bio)
 {
 	int i;
@@ -113,6 +115,7 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
 	u64 offset = map->m_la;
 	struct erofs_vnode *vi = EROFS_V(inode);
 
+	trace_erofs_map_blocks_flatmode_enter(inode, map, flags);
 	BUG_ON(is_inode_layout_compression(inode));
 
 	nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
@@ -150,8 +153,7 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
 
 out:
 	map->m_llen = map->m_plen;
-	debugln("%s, m_la 0x%llx m_pa %llx m_len %llu",
-		__func__, map->m_la, map->m_pa, map->m_plen);
+	trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
 	return 0;
 }
 
@@ -305,6 +307,8 @@ static int erofs_raw_access_readpage(struct file *file, struct page *page)
 	erofs_off_t last_block;
 	struct bio *bio;
 
+	trace_erofs_readpage(page, true);
+
 	bio = erofs_read_raw_page(NULL, page->mapping,
 		page, &last_block, 1, false);
 
@@ -322,9 +326,12 @@ static int erofs_raw_access_readpages(struct file *filp,
 	erofs_off_t last_block;
 	struct bio *bio = NULL;
 	gfp_t gfp = readahead_gfp_mask(mapping);
+	struct page *page = list_last_entry(pages, struct page, lru);
+
+	trace_erofs_readpages(mapping->host, page, nr_pages, true);
 
 	for (; nr_pages; --nr_pages) {
-		struct page *page = list_entry(pages->prev, struct page, lru);
+		page = list_entry(pages->prev, struct page, lru);
 
 		prefetchw(&page->flags);
 		list_del(&page->lru);
diff --git a/drivers/staging/erofs/include/trace/events/erofs.h b/drivers/staging/erofs/include/trace/events/erofs.h
new file mode 100644
index 0000000..5aead93
--- /dev/null
+++ b/drivers/staging/erofs/include/trace/events/erofs.h
@@ -0,0 +1,240 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM erofs
+
+#if !defined(_TRACE_EROFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EROFS_H
+
+#include <linux/tracepoint.h>
+
+#define show_dev(dev)		MAJOR(dev), MINOR(dev)
+#define show_dev_nid(entry)	show_dev(entry->dev), entry->nid
+
+#define show_file_type(type)						\
+	__print_symbolic(type,						\
+		{ 0,		"FILE" },				\
+		{ 1,		"DIR" })
+
+#define show_map_flags(flags) __print_flags(flags, "|",	\
+	{ EROFS_GET_BLOCKS_RAW,	"RAW" })
+
+#define show_mflags(flags) __print_flags(flags, "",	\
+	{ EROFS_MAP_MAPPED,	"M" },			\
+	{ EROFS_MAP_META,	"I" },			\
+	{ EROFS_MAP_ZIPPED,	"Z" })
+
+TRACE_EVENT(erofs_lookup,
+
+	TP_PROTO(struct inode *dir, struct dentry *dentry, unsigned int flags),
+
+	TP_ARGS(dir, dentry, flags),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev	)
+		__field(erofs_nid_t,	nid	)
+		__field(const char *,	name	)
+		__field(unsigned int,	flags	)
+	),
+
+	TP_fast_assign(
+		__entry->dev	= dir->i_sb->s_dev;
+		__entry->nid	= EROFS_V(dir)->nid;
+		__entry->name	= dentry->d_name.name;
+		__entry->flags	= flags;
+	),
+
+	TP_printk("dev = (%d,%d), pnid = %llu, name:%s, flags:%x",
+		show_dev_nid(__entry),
+		__entry->name,
+		__entry->flags)
+);
+
+TRACE_EVENT(erofs_fill_inode,
+	TP_PROTO(struct inode *inode, int isdir),
+	TP_ARGS(inode, isdir),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev	)
+		__field(erofs_nid_t,	nid	)
+		__field(erofs_blk_t,	blkaddr )
+		__field(unsigned int,	ofs	)
+		__field(int,		isdir	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->nid		= EROFS_V(inode)->nid;
+		__entry->blkaddr	= erofs_blknr(iloc(EROFS_I_SB(inode), __entry->nid));
+		__entry->ofs		= erofs_blkoff(iloc(EROFS_I_SB(inode), __entry->nid));
+		__entry->isdir		= isdir;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu, blkaddr %u ofs %u, isdir %d",
+		  show_dev_nid(__entry),
+		  __entry->blkaddr, __entry->ofs,
+		  __entry->isdir)
+);
+
+TRACE_EVENT(erofs_readpage,
+
+	TP_PROTO(struct page *page, bool raw),
+
+	TP_ARGS(page, raw),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev	)
+		__field(erofs_nid_t,    nid     )
+		__field(int,		dir	)
+		__field(pgoff_t,	index	)
+		__field(int,		uptodate)
+		__field(bool,		raw	)
+	),
+
+	TP_fast_assign(
+		__entry->dev	= page->mapping->host->i_sb->s_dev;
+		__entry->nid	= EROFS_V(page->mapping->host)->nid;
+		__entry->dir	= S_ISDIR(page->mapping->host->i_mode);
+		__entry->index	= page->index;
+		__entry->uptodate = PageUptodate(page);
+		__entry->raw = raw;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu, %s, index = %lu, uptodate = %d "
+		"raw = %d",
+		show_dev_nid(__entry),
+		show_file_type(__entry->dir),
+		(unsigned long)__entry->index,
+		__entry->uptodate,
+		__entry->raw)
+);
+
+TRACE_EVENT(erofs_readpages,
+
+	TP_PROTO(struct inode *inode, struct page *page, unsigned int nrpage,
+		bool raw),
+
+	TP_ARGS(inode, page, nrpage, raw),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev	)
+		__field(erofs_nid_t,	nid	)
+		__field(pgoff_t,	start	)
+		__field(unsigned int,	nrpage	)
+		__field(bool,		raw	)
+	),
+
+	TP_fast_assign(
+		__entry->dev	= inode->i_sb->s_dev;
+		__entry->nid	= EROFS_V(inode)->nid;
+		__entry->start	= page->index;
+		__entry->nrpage	= nrpage;
+		__entry->raw	= raw;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu, start = %lu nrpage = %u raw = %d",
+		show_dev_nid(__entry),
+		(unsigned long)__entry->start,
+		__entry->nrpage,
+		__entry->raw)
+);
+
+DECLARE_EVENT_CLASS(erofs__map_blocks_enter,
+	TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+		 unsigned int flags),
+
+	TP_ARGS(inode, map, flags),
+
+	TP_STRUCT__entry(
+		__field(	dev_t,		dev		)
+		__field(	erofs_nid_t,	nid		)
+		__field(	erofs_off_t,	la		)
+		__field(	u64,		llen		)
+		__field(	unsigned int,	flags		)
+	),
+
+	TP_fast_assign(
+		__entry->dev    = inode->i_sb->s_dev;
+		__entry->nid    = EROFS_V(inode)->nid;
+		__entry->la	= map->m_la;
+		__entry->llen	= map->m_llen;
+		__entry->flags	= flags;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu, la %llu llen %llu flags %s",
+		  show_dev_nid(__entry),
+		  __entry->la, __entry->llen, show_map_flags(__entry->flags))
+);
+
+DEFINE_EVENT(erofs__map_blocks_enter, erofs_map_blocks_flatmode_enter,
+	TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+		 unsigned flags),
+
+	TP_ARGS(inode, map, flags)
+);
+
+DECLARE_EVENT_CLASS(erofs__map_blocks_exit,
+	TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+		 unsigned int flags, int ret),
+
+	TP_ARGS(inode, map, flags, ret),
+
+	TP_STRUCT__entry(
+		__field(	dev_t,		dev		)
+		__field(	erofs_nid_t,	nid		)
+		__field(        unsigned int,   flags           )
+		__field(	erofs_off_t,	la		)
+		__field(	erofs_off_t,	pa		)
+		__field(	u64,		llen		)
+		__field(	u64,		plen		)
+		__field(        unsigned int,	mflags		)
+		__field(	int,		ret		)
+	),
+
+	TP_fast_assign(
+		__entry->dev    = inode->i_sb->s_dev;
+		__entry->nid    = EROFS_V(inode)->nid;
+		__entry->flags	= flags;
+		__entry->la	= map->m_la;
+		__entry->pa	= map->m_pa;
+		__entry->llen	= map->m_llen;
+		__entry->plen	= map->m_plen;
+		__entry->mflags	= map->m_flags;
+		__entry->ret	= ret;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu, flags %s "
+		  "la %llu pa %llu llen %llu plen %llu mflags %s ret %d",
+		  show_dev_nid(__entry), show_map_flags(__entry->flags),
+		  __entry->la, __entry->pa, __entry->llen, __entry->plen,
+		  show_mflags(__entry->mflags), __entry->ret)
+);
+
+DEFINE_EVENT(erofs__map_blocks_exit, erofs_map_blocks_flatmode_exit,
+	TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+		 unsigned flags, int ret),
+
+	TP_ARGS(inode, map, flags, ret)
+);
+
+TRACE_EVENT(erofs_destroy_inode,
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode),
+
+	TP_STRUCT__entry(
+		__field(	dev_t,		dev		)
+		__field(	erofs_nid_t,	nid		)
+	),
+
+	TP_fast_assign(
+		__entry->dev	= inode->i_sb->s_dev;
+		__entry->nid	= EROFS_V(inode)->nid;
+	),
+
+	TP_printk("dev = (%d,%d), nid = %llu", show_dev_nid(__entry))
+);
+
+#endif /* _TRACE_EROFS_H */
+
+ /* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index a6d3e12..613c977 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -12,6 +12,8 @@
  */
 #include "xattr.h"
 
+#include <trace/events/erofs.h>
+
 /* no locking */
 static int read_inode(struct inode *inode, void *data)
 {
@@ -152,6 +154,8 @@ static int fill_inode(struct inode *inode, int isdir)
 	erofs_blk_t blkaddr;
 	unsigned ofs;
 
+	trace_erofs_fill_inode(inode, isdir);
+
 	blkaddr = erofs_blknr(iloc(sbi, vi->nid));
 	ofs = erofs_blkoff(iloc(sbi, vi->nid));
 
diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
index 989876b..d2a0da3 100644
--- a/drivers/staging/erofs/namei.c
+++ b/drivers/staging/erofs/namei.c
@@ -13,6 +13,8 @@
 #include "internal.h"
 #include "xattr.h"
 
+#include <trace/events/erofs.h>
+
 /* based on the value of qn->len is accurate */
 static inline int dirnamecmp(struct qstr *qn,
 	struct qstr *qd, unsigned *matched)
@@ -209,6 +211,8 @@ static struct dentry *erofs_lookup(struct inode *dir,
 	/* dentry must be unhashed in lookup, no need to worry about */
 	DBG_BUGON(!d_unhashed(dentry));
 
+	trace_erofs_lookup(dir, dentry, flags);
+
 	/* file name exceeds fs limit */
 	if (unlikely(dentry->d_name.len > EROFS_NAME_LEN))
 		return ERR_PTR(-ENAMETOOLONG);
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 701425f..054375d 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -17,6 +17,9 @@
 #include <linux/seq_file.h>
 #include "internal.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/erofs.h>
+
 static struct kmem_cache *erofs_inode_cachep __read_mostly;
 
 static void init_once(void *ptr)
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 13/25] staging: erofs: <linux/tagptr.h>: introduce tagged pointer
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (11 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 12/25] staging: erofs: support tracepoint Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 14/25] staging: erofs: introduce pagevec for unzip subsystem Gao Xiang
                     ` (13 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

Currently kernel has scattered tagged pointer usages hacked
by hand in plain code, without a unique and portable functionset
to highlight the tagged pointer itself and wrap these hacked code
in order to clean up all over meaningless magic masks.

Therefore, this patch introduces simple generic methods to fold
tags into a pointer integer. It currently supports the last n bits
of the pointer for tags, which can be selected by users.

In addition, it will also be used for the upcoming EROFS filesystem,
which heavily uses tagged pointer approach for high performance
and reducing extra memory allocation.

Link: https://en.wikipedia.org/wiki/Tagged_pointer

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/include/linux/tagptr.h | 110 +++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 drivers/staging/erofs/include/linux/tagptr.h

diff --git a/drivers/staging/erofs/include/linux/tagptr.h b/drivers/staging/erofs/include/linux/tagptr.h
new file mode 100644
index 0000000..ccd106d
--- /dev/null
+++ b/drivers/staging/erofs/include/linux/tagptr.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Tagged pointer implementation
+ *
+ * Copyright (C) 2018 Gao Xiang <gaoxiang25@huawei.com>
+ */
+#ifndef _LINUX_TAGPTR_H
+#define _LINUX_TAGPTR_H
+
+#include <linux/types.h>
+#include <linux/build_bug.h>
+
+/*
+ * the name of tagged pointer types are tagptr{1, 2, 3...}_t
+ * avoid directly using the internal structs __tagptr{1, 2, 3...}
+ */
+#define __MAKE_TAGPTR(n) \
+typedef struct __tagptr##n {	\
+	uintptr_t v;	\
+} tagptr##n##_t;
+
+__MAKE_TAGPTR(1)
+__MAKE_TAGPTR(2)
+__MAKE_TAGPTR(3)
+__MAKE_TAGPTR(4)
+
+#undef __MAKE_TAGPTR
+
+extern void __compiletime_error("bad tagptr tags")
+	__bad_tagptr_tags(void);
+
+extern void __compiletime_error("bad tagptr type")
+	__bad_tagptr_type(void);
+
+/* fix the broken usage of "#define tagptr2_t tagptr3_t" by users */
+#define __tagptr_mask_1(ptr, n)	\
+	__builtin_types_compatible_p(typeof(ptr), struct __tagptr##n) ? \
+		(1UL << (n)) - 1 :
+
+#define __tagptr_mask(ptr)	(\
+	__tagptr_mask_1(ptr, 1) ( \
+	__tagptr_mask_1(ptr, 2) ( \
+	__tagptr_mask_1(ptr, 3) ( \
+	__tagptr_mask_1(ptr, 4) ( \
+	__bad_tagptr_type(), 0)))))
+
+/* generate a tagged pointer from a raw value */
+#define tagptr_init(type, val) \
+	((typeof(type)){ .v = (uintptr_t)(val) })
+
+/*
+ * directly cast a tagged pointer to the native pointer type, which
+ * could be used for backward compatibility of existing code.
+ */
+#define tagptr_cast_ptr(tptr) ((void *)(tptr).v)
+
+/* encode tagged pointers */
+#define tagptr_fold(type, ptr, _tags) ({ \
+	const typeof(_tags) tags = (_tags); \
+	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(type))) \
+		__bad_tagptr_tags(); \
+tagptr_init(type, (uintptr_t)(ptr) | tags); })
+
+/* decode tagged pointers */
+#define tagptr_unfold_ptr(tptr) \
+	((void *)((tptr).v & ~__tagptr_mask(tptr)))
+
+#define tagptr_unfold_tags(tptr) \
+	((tptr).v & __tagptr_mask(tptr))
+
+/* operations for the tagger pointer */
+#define tagptr_eq(_tptr1, _tptr2) ({ \
+	typeof(_tptr1) tptr1 = (_tptr1); \
+	typeof(_tptr2) tptr2 = (_tptr2); \
+	(void)(&tptr1 == &tptr2); \
+(tptr1).v == (tptr2).v; })
+
+/* lock-free CAS operation */
+#define tagptr_cmpxchg(_ptptr, _o, _n) ({ \
+	typeof(_ptptr) ptptr = (_ptptr); \
+	typeof(_o) o = (_o); \
+	typeof(_n) n = (_n); \
+	(void)(&o == &n); \
+	(void)(&o == ptptr); \
+tagptr_init(o, cmpxchg(&ptptr->v, o.v, n.v)); })
+
+/* wrap WRITE_ONCE if atomic update is needed */
+#define tagptr_replace_tags(_ptptr, tags) ({ \
+	typeof(_ptptr) ptptr = (_ptptr); \
+	*ptptr = tagptr_fold(*ptptr, tagptr_unfold_ptr(*ptptr), tags); \
+*ptptr; })
+
+#define tagptr_set_tags(_ptptr, _tags) ({ \
+	typeof(_ptptr) ptptr = (_ptptr); \
+	const typeof(_tags) tags = (_tags); \
+	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \
+		__bad_tagptr_tags(); \
+	ptptr->v |= tags; \
+*ptptr; })
+
+#define tagptr_clear_tags(_ptptr, _tags) ({ \
+	typeof(_ptptr) ptptr = (_ptptr); \
+	const typeof(_tags) tags = (_tags); \
+	if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \
+		__bad_tagptr_tags(); \
+	ptptr->v &= ~tags; \
+*ptptr; })
+
+#endif
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 14/25] staging: erofs: introduce pagevec for unzip subsystem
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (12 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 13/25] staging: erofs: <linux/tagptr.h>: introduce tagged pointer Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 15/25] staging: erofs: add erofs_map_blocks_iter Gao Xiang
                     ` (12 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

For each compressed cluster, there is a straight-forward
way of allocating a fixed or variable-sized (for VLE) array
to record the corresponding file pages for its decompression
if we decide to decompress these pages asynchronously (eg.
read-ahead case), however it could take much extra on-heap
memory compared with traditional uncompressed filesystems.

This patch introduces a pagevec solution to reuse some
allocated file page in the time-sharing approach storing
parts of the array itself in order to minimize the extra
memory overhead, thus only a constant and small-sized array
used for booting the whole array itself up will be needed.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/unzip_pagevec.h | 172 ++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 drivers/staging/erofs/unzip_pagevec.h

diff --git a/drivers/staging/erofs/unzip_pagevec.h b/drivers/staging/erofs/unzip_pagevec.h
new file mode 100644
index 0000000..0956615
--- /dev/null
+++ b/drivers/staging/erofs/unzip_pagevec.h
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/drivers/staging/erofs/unzip_pagevec.h
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#ifndef __EROFS_UNZIP_PAGEVEC_H
+#define __EROFS_UNZIP_PAGEVEC_H
+
+#include <linux/tagptr.h>
+
+/* page type in pagevec for unzip subsystem */
+enum z_erofs_page_type {
+	/* including Z_EROFS_VLE_PAGE_TAIL_EXCLUSIVE */
+	Z_EROFS_PAGE_TYPE_EXCLUSIVE,
+
+	Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED,
+
+	Z_EROFS_VLE_PAGE_TYPE_HEAD,
+	Z_EROFS_VLE_PAGE_TYPE_MAX
+};
+
+extern void __compiletime_error("Z_EROFS_PAGE_TYPE_EXCLUSIVE != 0")
+	__bad_page_type_exclusive(void);
+
+/* pagevec tagged pointer */
+typedef tagptr2_t	erofs_vtptr_t;
+
+/* pagevec collector */
+struct z_erofs_pagevec_ctor {
+	struct page *curr, *next;
+	erofs_vtptr_t *pages;
+
+	unsigned int nr, index;
+};
+
+static inline void z_erofs_pagevec_ctor_exit(struct z_erofs_pagevec_ctor *ctor,
+					     bool atomic)
+{
+	if (ctor->curr == NULL)
+		return;
+
+	if (atomic)
+		kunmap_atomic(ctor->pages);
+	else
+		kunmap(ctor->curr);
+}
+
+static inline struct page *
+z_erofs_pagevec_ctor_next_page(struct z_erofs_pagevec_ctor *ctor,
+			       unsigned nr)
+{
+	unsigned index;
+
+	/* keep away from occupied pages */
+	if (ctor->next != NULL)
+		return ctor->next;
+
+	for (index = 0; index < nr; ++index) {
+		const erofs_vtptr_t t = ctor->pages[index];
+		const unsigned tags = tagptr_unfold_tags(t);
+
+		if (tags == Z_EROFS_PAGE_TYPE_EXCLUSIVE)
+			return tagptr_unfold_ptr(t);
+	}
+
+	if (unlikely(nr >= ctor->nr))
+		BUG();
+
+	return NULL;
+}
+
+static inline void
+z_erofs_pagevec_ctor_pagedown(struct z_erofs_pagevec_ctor *ctor,
+			      bool atomic)
+{
+	struct page *next = z_erofs_pagevec_ctor_next_page(ctor, ctor->nr);
+
+	z_erofs_pagevec_ctor_exit(ctor, atomic);
+
+	ctor->curr = next;
+	ctor->next = NULL;
+	ctor->pages = atomic ?
+		kmap_atomic(ctor->curr) : kmap(ctor->curr);
+
+	ctor->nr = PAGE_SIZE / sizeof(struct page *);
+	ctor->index = 0;
+}
+
+static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor,
+					     unsigned nr,
+					     erofs_vtptr_t *pages, unsigned i)
+{
+	ctor->nr = nr;
+	ctor->curr = ctor->next = NULL;
+	ctor->pages = pages;
+
+	if (i >= nr) {
+		i -= nr;
+		z_erofs_pagevec_ctor_pagedown(ctor, false);
+		while (i > ctor->nr) {
+			i -= ctor->nr;
+			z_erofs_pagevec_ctor_pagedown(ctor, false);
+		}
+	}
+
+	ctor->next = z_erofs_pagevec_ctor_next_page(ctor, i);
+	ctor->index = i;
+}
+
+static inline bool
+z_erofs_pagevec_ctor_enqueue(struct z_erofs_pagevec_ctor *ctor,
+			     struct page *page,
+			     enum z_erofs_page_type type,
+			     bool *occupied)
+{
+	*occupied = false;
+	if (unlikely(ctor->next == NULL && type))
+		if (ctor->index + 1 == ctor->nr)
+			return false;
+
+	if (unlikely(ctor->index >= ctor->nr))
+		z_erofs_pagevec_ctor_pagedown(ctor, false);
+
+	/* exclusive page type must be 0 */
+	if (Z_EROFS_PAGE_TYPE_EXCLUSIVE != (uintptr_t)NULL)
+		__bad_page_type_exclusive();
+
+	/* should remind that collector->next never equal to 1, 2 */
+	if (type == (uintptr_t)ctor->next) {
+		ctor->next = page;
+		*occupied = true;
+	}
+
+	ctor->pages[ctor->index++] =
+		tagptr_fold(erofs_vtptr_t, page, type);
+	return true;
+}
+
+static inline struct page *
+z_erofs_pagevec_ctor_dequeue(struct z_erofs_pagevec_ctor *ctor,
+			     enum z_erofs_page_type *type)
+{
+	erofs_vtptr_t t;
+
+	if (unlikely(ctor->index >= ctor->nr)) {
+		BUG_ON(ctor->next == NULL);
+		z_erofs_pagevec_ctor_pagedown(ctor, true);
+	}
+
+	t = ctor->pages[ctor->index];
+
+	*type = tagptr_unfold_tags(t);
+
+	/* should remind that collector->next never equal to 1, 2 */
+	if (*type == (uintptr_t)ctor->next)
+		ctor->next = tagptr_unfold_ptr(t);
+
+	ctor->pages[ctor->index++] =
+		tagptr_fold(erofs_vtptr_t, NULL, 0);
+
+	return tagptr_unfold_ptr(t);
+}
+
+#endif
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 15/25] staging: erofs: add erofs_map_blocks_iter
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (13 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 14/25] staging: erofs: introduce pagevec for unzip subsystem Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:21   ` [PATCH 16/25] staging: erofs: add erofs_allocpage Gao Xiang
                     ` (11 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch introduces an iterable L2P mapping
operation 'erofs_map_blocks_iter'.
Compared with 'erofs_map_blocks', it avoids
a number of redundant 'release and regrab'
processes if they request the same meta page.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Kconfig     |  10 ++
 drivers/staging/erofs/Makefile    |   1 +
 drivers/staging/erofs/data.c      |  36 +++++-
 drivers/staging/erofs/internal.h  |  12 ++
 drivers/staging/erofs/unzip_vle.c | 243 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 300 insertions(+), 2 deletions(-)
 create mode 100644 drivers/staging/erofs/unzip_vle.c

diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index edda055..63bec70 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -77,3 +77,13 @@ config EROFS_FAULT_INJECTION
 	help
 	  Test EROFS to inject faults such as ENOMEM, EIO, and so on.
 	  If unsure, say N.
+
+config EROFS_FS_ZIP
+	bool "EROFS Data Compresssion Support"
+	depends on EROFS_FS
+	help
+	  Currently we support VLE Compression only.
+	  Play at your own risk.
+
+	  If you don't want to use compression feature, say N.
+
diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index 977b7e0..8558c76 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
 ccflags-y += -I$(src)/include
 erofs-objs := super.o inode.o data.o namei.o dir.o
 erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o
 
diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index 47d1787..163bfe6 100644
--- a/drivers/staging/erofs/data.c
+++ b/drivers/staging/erofs/data.c
@@ -157,12 +157,44 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
 	return 0;
 }
 
+#ifdef CONFIG_EROFS_FS_ZIP
+extern int z_erofs_map_blocks_iter(struct inode *,
+	struct erofs_map_blocks *, struct page **, int);
+#endif
+
+int erofs_map_blocks_iter(struct inode *inode,
+	struct erofs_map_blocks *map,
+	struct page **mpage_ret, int flags)
+{
+	/* by default, reading raw data never use erofs_map_blocks_iter */
+	if (unlikely(!is_inode_layout_compression(inode))) {
+		if (*mpage_ret != NULL)
+			put_page(*mpage_ret);
+		*mpage_ret = NULL;
+
+		return erofs_map_blocks(inode, map, flags);
+	}
+
+#ifdef CONFIG_EROFS_FS_ZIP
+	return z_erofs_map_blocks_iter(inode, map, mpage_ret, flags);
+#else
+	/* data compression is not available */
+	return -ENOTSUPP;
+#endif
+}
+
 int erofs_map_blocks(struct inode *inode,
 	struct erofs_map_blocks *map, int flags)
 {
-	if (unlikely(is_inode_layout_compression(inode)))
-		return -ENOTSUPP;
+	if (unlikely(is_inode_layout_compression(inode))) {
+		struct page *mpage = NULL;
+		int err;
 
+		err = erofs_map_blocks_iter(inode, map, &mpage, flags);
+		if (mpage != NULL)
+			put_page(mpage);
+		return err;
+	}
 	return erofs_map_blocks_flatmode(inode, map, flags);
 }
 
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index ca22486..bea5ec4 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -72,6 +72,10 @@ struct erofs_sb_info {
 
 	/* inode slot unit size in bit shift */
 	unsigned char islotbits;
+#ifdef CONFIG_EROFS_FS_ZIP
+	/* cluster size in bit shift */
+	unsigned char clusterbits;
+#endif
 
 	u32 build_time_nsec;
 	u64 build_time;
@@ -284,6 +288,14 @@ struct erofs_map_blocks {
 extern struct page *erofs_get_meta_page(struct super_block *sb,
 	erofs_blk_t blkaddr, bool prio);
 extern int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
+extern int erofs_map_blocks_iter(struct inode *, struct erofs_map_blocks *,
+	struct page **, int);
+
+struct erofs_map_blocks_iter {
+	struct erofs_map_blocks map;
+	struct page *mpage;
+};
+
 
 static inline struct page *erofs_get_inline_page(struct inode *inode,
 	erofs_blk_t blkaddr)
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
new file mode 100644
index 0000000..329cbe4
--- /dev/null
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/unzip_vle.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "internal.h"
+
+#define __vle_cluster_advise(x, bit, bits) \
+	((le16_to_cpu(x) >> (bit)) & ((1 << (bits)) - 1))
+
+#define __vle_cluster_type(advise) __vle_cluster_advise(advise, \
+	Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT, Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS)
+
+enum {
+	Z_EROFS_VLE_CLUSTER_TYPE_PLAIN,
+	Z_EROFS_VLE_CLUSTER_TYPE_HEAD,
+	Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD,
+	Z_EROFS_VLE_CLUSTER_TYPE_RESERVED,
+	Z_EROFS_VLE_CLUSTER_TYPE_MAX
+};
+
+#define vle_cluster_type(di)	\
+	__vle_cluster_type((di)->di_advise)
+
+static inline unsigned
+vle_compressed_index_clusterofs(unsigned clustersize,
+	struct z_erofs_vle_decompressed_index *di)
+{
+	debugln("%s, vle=%pK, advise=%x (type %u), clusterofs=%x blkaddr=%x",
+		__func__, di, di->di_advise, vle_cluster_type(di),
+		di->di_clusterofs, di->di_u.blkaddr);
+
+	switch (vle_cluster_type(di)) {
+	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+		break;
+	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+		return di->di_clusterofs;
+	default:
+		BUG_ON(1);
+	}
+	return clustersize;
+}
+
+static inline erofs_blk_t
+vle_extent_blkaddr(struct inode *inode, pgoff_t index)
+{
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+	struct erofs_vnode *vi = EROFS_V(inode);
+
+	unsigned ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize +
+		vi->xattr_isize) + sizeof(struct erofs_extent_header) +
+		index * sizeof(struct z_erofs_vle_decompressed_index);
+
+	return erofs_blknr(iloc(sbi, vi->nid) + ofs);
+}
+
+static inline unsigned int
+vle_extent_blkoff(struct inode *inode, pgoff_t index)
+{
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+	struct erofs_vnode *vi = EROFS_V(inode);
+
+	unsigned ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize +
+		vi->xattr_isize) + sizeof(struct erofs_extent_header) +
+		index * sizeof(struct z_erofs_vle_decompressed_index);
+
+	return erofs_blkoff(iloc(sbi, vi->nid) + ofs);
+}
+
+/*
+ * Variable-sized Logical Extent (Fixed Physical Cluster) Compression Mode
+ * ---
+ * VLE compression mode attempts to compress a number of logical data into
+ * a physical cluster with a fixed size.
+ * VLE compression mode uses "struct z_erofs_vle_decompressed_index".
+ */
+static erofs_off_t vle_get_logical_extent_head(
+	struct inode *inode,
+	struct page **page_iter,
+	void **kaddr_iter,
+	unsigned lcn,	/* logical cluster number */
+	erofs_blk_t *pcn,
+	unsigned *flags)
+{
+	/* for extent meta */
+	struct page *page = *page_iter;
+	erofs_blk_t blkaddr = vle_extent_blkaddr(inode, lcn);
+	struct z_erofs_vle_decompressed_index *di;
+	unsigned long long ofs;
+	const unsigned int clusterbits = EROFS_SB(inode->i_sb)->clusterbits;
+	const unsigned int clustersize = 1 << clusterbits;
+
+	if (page->index != blkaddr) {
+		kunmap_atomic(*kaddr_iter);
+		unlock_page(page);
+		put_page(page);
+
+		*page_iter = page = erofs_get_meta_page(inode->i_sb,
+			blkaddr, false);
+		*kaddr_iter = kmap_atomic(page);
+	}
+
+	di = *kaddr_iter + vle_extent_blkoff(inode, lcn);
+	switch (vle_cluster_type(di)) {
+	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+		BUG_ON(!di->di_u.delta[0]);
+		BUG_ON(lcn < di->di_u.delta[0]);
+
+		ofs = vle_get_logical_extent_head(inode,
+			page_iter, kaddr_iter,
+			lcn - di->di_u.delta[0], pcn, flags);
+		break;
+	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+		*flags ^= EROFS_MAP_ZIPPED;
+	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+		/* clustersize should be a power of two */
+		ofs = ((unsigned long long)lcn << clusterbits) +
+			(le16_to_cpu(di->di_clusterofs) & (clustersize - 1));
+		*pcn = le32_to_cpu(di->di_u.blkaddr);
+		break;
+	default:
+		BUG_ON(1);
+	}
+	return ofs;
+}
+
+int z_erofs_map_blocks_iter(struct inode *inode,
+	struct erofs_map_blocks *map,
+	struct page **mpage_ret, int flags)
+{
+	/* logicial extent (start, end) offset */
+	unsigned long long ofs, end;
+	struct z_erofs_vle_decompressed_index *di;
+	erofs_blk_t e_blkaddr, pcn;
+	unsigned lcn, logical_cluster_ofs;
+	u32 ofs_rem;
+	struct page *mpage = *mpage_ret;
+	void *kaddr;
+	bool initial;
+	const unsigned int clusterbits = EROFS_SB(inode->i_sb)->clusterbits;
+	const unsigned int clustersize = 1 << clusterbits;
+
+	/* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */
+	initial = !map->m_llen;
+
+	/* when trying to read beyond EOF, leave it unmapped */
+	if (unlikely(map->m_la >= inode->i_size)) {
+		BUG_ON(!initial);
+		map->m_llen = map->m_la + 1 - inode->i_size;
+		map->m_la = inode->i_size - 1;
+		map->m_flags = 0;
+		goto out;
+	}
+
+	debugln("%s, m_la %llu m_llen %llu --- start", __func__,
+		map->m_la, map->m_llen);
+
+	ofs = map->m_la + map->m_llen;
+
+	/* clustersize should be power of two */
+	lcn = ofs >> clusterbits;
+	ofs_rem = ofs & (clustersize - 1);
+
+	e_blkaddr = vle_extent_blkaddr(inode, lcn);
+
+	if (mpage == NULL || mpage->index != e_blkaddr) {
+		if (mpage != NULL)
+			put_page(mpage);
+
+		mpage = erofs_get_meta_page(inode->i_sb, e_blkaddr, false);
+		*mpage_ret = mpage;
+	} else {
+		lock_page(mpage);
+		DBG_BUGON(!PageUptodate(mpage));
+	}
+
+	kaddr = kmap_atomic(mpage);
+	di = kaddr + vle_extent_blkoff(inode, lcn);
+
+	debugln("%s, lcn %u e_blkaddr %u e_blkoff %u", __func__, lcn,
+		e_blkaddr, vle_extent_blkoff(inode, lcn));
+
+	logical_cluster_ofs = vle_compressed_index_clusterofs(clustersize, di);
+	if (!initial) {
+		/* [walking mode] 'map' has been already initialized */
+		map->m_llen += logical_cluster_ofs;
+		goto unmap_out;
+	}
+
+	/* by default, compressed */
+	map->m_flags |= EROFS_MAP_ZIPPED;
+
+	end = (u64)(lcn + 1) * clustersize;
+
+	switch (vle_cluster_type(di)) {
+	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+		if (ofs_rem >= logical_cluster_ofs)
+			map->m_flags ^= EROFS_MAP_ZIPPED;
+	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+		if (ofs_rem == logical_cluster_ofs) {
+			pcn = le32_to_cpu(di->di_u.blkaddr);
+			goto exact_hitted;
+		}
+
+		if (ofs_rem > logical_cluster_ofs) {
+			ofs = lcn * clustersize | logical_cluster_ofs;
+			pcn = le32_to_cpu(di->di_u.blkaddr);
+			break;
+		}
+
+		BUG_ON(!lcn);	/* logical cluster number >= 1 */
+		end = (lcn-- * clustersize) | logical_cluster_ofs;
+	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+		/* get the correspoinding first chunk */
+		ofs = vle_get_logical_extent_head(inode, mpage_ret,
+			&kaddr, lcn, &pcn, &map->m_flags);
+		mpage = *mpage_ret;
+	}
+
+	map->m_la = ofs;
+exact_hitted:
+	map->m_llen = end - ofs;
+	map->m_plen = clustersize;
+	map->m_pa = blknr_to_addr(pcn);
+	map->m_flags |= EROFS_MAP_MAPPED;
+unmap_out:
+	kunmap_atomic(kaddr);
+	unlock_page(mpage);
+out:
+	debugln("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
+		__func__, map->m_la, map->m_pa,
+		map->m_llen, map->m_plen, map->m_flags);
+	return 0;
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 16/25] staging: erofs: add erofs_allocpage
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (14 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 15/25] staging: erofs: add erofs_map_blocks_iter Gao Xiang
@ 2018-07-26 12:21   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 17/25] staging: erofs: globalize prepare_bio and __submit_bio Gao Xiang
                     ` (10 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:21 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch introduces an temporary _on-stack_ page
pool to reuse the freed page directly as much as
it can for better performance and release all pages
at a time, it also slightly reduces the possibility of
the potential memory allocation failure.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Makefile   |  2 +-
 drivers/staging/erofs/internal.h |  7 +++++++
 drivers/staging/erofs/utils.c    | 31 +++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/erofs/utils.c

diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index 8558c76..490fa6c 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -7,7 +7,7 @@ ccflags-y += -Wall -DEROFS_VERSION=\"$(EROFS_VERSION)\"
 obj-$(CONFIG_EROFS_FS) += erofs.o
 # staging requirement: to be self-contained in its own directory
 ccflags-y += -I$(src)/include
-erofs-objs := super.o inode.o data.o namei.o dir.o
+erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
 erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
 erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o
 
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index bea5ec4..210ab6c 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -369,5 +369,12 @@ static inline void erofs_vunmap(const void *mem, unsigned int count)
 #endif
 }
 
+/* utils.c */
+extern struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
+
+#ifndef lru_to_page
+#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
+#endif
+
 #endif
 
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
new file mode 100644
index 0000000..3dec4f8
--- /dev/null
+++ b/drivers/staging/erofs/utils.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/utils.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+
+#include "internal.h"
+
+struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
+{
+	struct page *page;
+
+	if (!list_empty(pool)) {
+		page = lru_to_page(pool);
+		list_del(&page->lru);
+	} else {
+		page = alloc_pages(gfp | __GFP_NOFAIL, 0);
+
+		BUG_ON(page == NULL);
+		BUG_ON(page->mapping != NULL);
+	}
+	return page;
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 17/25] staging: erofs: globalize prepare_bio and __submit_bio
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (15 preceding siblings ...)
  2018-07-26 12:21   ` [PATCH 16/25] staging: erofs: add erofs_allocpage Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 18/25] staging: erofs: introduce a customized LZ4 decompression Gao Xiang
                     ` (9 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

The unzip subsystem also uses these functions,
let's export them to internal.h.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/data.c     | 34 +++++++++-------------------------
 drivers/staging/erofs/internal.h | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 25 deletions(-)

diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index 163bfe6..ac263a1 100644
--- a/drivers/staging/erofs/data.c
+++ b/drivers/staging/erofs/data.c
@@ -38,26 +38,6 @@ static inline void read_endio(struct bio *bio)
 	bio_put(bio);
 }
 
-static void __submit_bio(struct bio *bio, unsigned op, unsigned op_flags)
-{
-	bio_set_op_attrs(bio, op, op_flags);
-	submit_bio(bio);
-}
-
-static struct bio *prepare_bio(struct super_block *sb,
-	erofs_blk_t blkaddr, unsigned nr_pages)
-{
-	struct bio *bio = bio_alloc(GFP_NOIO | __GFP_NOFAIL, nr_pages);
-
-	BUG_ON(bio == NULL);
-
-	bio->bi_end_io = read_endio;
-	bio_set_dev(bio, sb->s_bdev);
-	bio->bi_iter.bi_sector = blkaddr << LOG_SECTORS_PER_BLOCK;
-
-	return bio;
-}
-
 /* prio -- true is used for dir */
 struct page *erofs_get_meta_page(struct super_block *sb,
 	erofs_blk_t blkaddr, bool prio)
@@ -80,7 +60,7 @@ struct page *erofs_get_meta_page(struct super_block *sb,
 		struct bio *bio;
 		int err;
 
-		bio = prepare_bio(sb, blkaddr, 1);
+		bio = prepare_bio(sb, blkaddr, 1, read_endio);
 		err = bio_add_page(bio, page, PAGE_SIZE, 0);
 		BUG_ON(err != PAGE_SIZE);
 
@@ -236,6 +216,8 @@ static inline struct bio *erofs_read_raw_page(
 		struct erofs_map_blocks map = {
 			.m_la = blknr_to_addr(current_block),
 		};
+		erofs_blk_t blknr;
+		unsigned blkoff;
 
 		err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
 		if (unlikely(err))
@@ -253,6 +235,9 @@ static inline struct bio *erofs_read_raw_page(
 		/* for RAW access mode, m_plen must be equal to m_llen */
 		BUG_ON(map.m_plen != map.m_llen);
 
+		blknr = erofs_blknr(map.m_pa);
+		blkoff = erofs_blkoff(map.m_pa);
+
 		/* deal with inline page */
 		if (map.m_flags & EROFS_MAP_META) {
 			void *vsrc, *vto;
@@ -260,8 +245,7 @@ static inline struct bio *erofs_read_raw_page(
 
 			BUG_ON(map.m_plen > PAGE_SIZE);
 
-			ipage = erofs_get_meta_page(inode->i_sb,
-				erofs_blknr(map.m_pa), 0);
+			ipage = erofs_get_meta_page(inode->i_sb, blknr, 0);
 
 			if (IS_ERR(ipage)) {
 				err = PTR_ERR(ipage);
@@ -270,7 +254,7 @@ static inline struct bio *erofs_read_raw_page(
 
 			vsrc = kmap_atomic(ipage);
 			vto = kmap_atomic(page);
-			memcpy(vto, vsrc + erofs_blkoff(map.m_pa), map.m_plen);
+			memcpy(vto, vsrc + blkoff, map.m_plen);
 			memset(vto + map.m_plen, 0, PAGE_SIZE - map.m_plen);
 			kunmap_atomic(vto);
 			kunmap_atomic(vsrc);
@@ -294,7 +278,7 @@ static inline struct bio *erofs_read_raw_page(
 		if (nblocks > BIO_MAX_PAGES)
 			nblocks = BIO_MAX_PAGES;
 
-		bio = prepare_bio(inode->i_sb, erofs_blknr(map.m_pa), nblocks);
+		bio = prepare_bio(inode->i_sb, blknr, nblocks, read_endio);
 	}
 
 	err = bio_add_page(bio, page, PAGE_SIZE, 0);
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 210ab6c..6a0f045 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -285,6 +285,39 @@ struct erofs_map_blocks {
 #define EROFS_GET_BLOCKS_RAW    0x0001
 
 /* data.c */
+static inline struct bio *prepare_bio(
+	struct super_block *sb,
+	erofs_blk_t blkaddr, unsigned nr_pages,
+	bio_end_io_t endio)
+{
+	gfp_t gfp = GFP_NOIO;
+	struct bio *bio = bio_alloc(gfp, nr_pages);
+
+	if (unlikely(bio == NULL) &&
+		(current->flags & PF_MEMALLOC)) {
+		do {
+			nr_pages /= 2;
+			if (unlikely(!nr_pages)) {
+				bio = bio_alloc(gfp | __GFP_NOFAIL, 1);
+				BUG_ON(bio == NULL);
+				break;
+			}
+			bio = bio_alloc(gfp, nr_pages);
+		} while (bio == NULL);
+	}
+
+	bio->bi_end_io = endio;
+	bio_set_dev(bio, sb->s_bdev);
+	bio->bi_iter.bi_sector = blkaddr << LOG_SECTORS_PER_BLOCK;
+	return bio;
+}
+
+static inline void __submit_bio(struct bio *bio, unsigned op, unsigned op_flags)
+{
+	bio_set_op_attrs(bio, op, op_flags);
+	submit_bio(bio);
+}
+
 extern struct page *erofs_get_meta_page(struct super_block *sb,
 	erofs_blk_t blkaddr, bool prio);
 extern int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 18/25] staging: erofs: introduce a customized LZ4 decompression
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (16 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 17/25] staging: erofs: globalize prepare_bio and __submit_bio Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 19/25] staging: erofs: add a generic z_erofs VLE decompressor Gao Xiang
                     ` (8 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

We have to reduce the memory cost as much as possible,
so we don't want to decompress more data beyond
the output buffer size, however "LZ4_decompress_safe_partial"
doesn't guarantee to stop at the arbitary end position,
but stop just after its current LZ4 "sequence" is completed.

Link: https://groups.google.com/forum/#!topic/lz4c/_3kkz5N6n00

Therefore, I hacked the LZ4 decompression logic by hand,
probably NOT the fastest approach, and hope for better
implementation.

Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Makefile    |   2 +-
 drivers/staging/erofs/lz4defs.h   | 227 ++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/unzip_lz4.c | 251 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 479 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/erofs/lz4defs.h
 create mode 100644 drivers/staging/erofs/unzip_lz4.c

diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index 490fa6c..e409637 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -9,5 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
 ccflags-y += -I$(src)/include
 erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
 erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
-erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o
 
diff --git a/drivers/staging/erofs/lz4defs.h b/drivers/staging/erofs/lz4defs.h
new file mode 100644
index 0000000..00a0b58
--- /dev/null
+++ b/drivers/staging/erofs/lz4defs.h
@@ -0,0 +1,227 @@
+#ifndef __LZ4DEFS_H__
+#define __LZ4DEFS_H__
+
+/*
+ * lz4defs.h -- common and architecture specific defines for the kernel usage
+
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011-2016, Yann Collet.
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+
+#include <asm/unaligned.h>
+#include <linux/string.h>	 /* memset, memcpy */
+
+#define FORCE_INLINE __always_inline
+
+/*-************************************
+ *	Basic Types
+ **************************************/
+#include <linux/types.h>
+
+typedef	uint8_t BYTE;
+typedef uint16_t U16;
+typedef uint32_t U32;
+typedef	int32_t S32;
+typedef uint64_t U64;
+typedef uintptr_t uptrval;
+
+/*-************************************
+ *	Architecture specifics
+ **************************************/
+#if defined(CONFIG_64BIT)
+#define LZ4_ARCH64 1
+#else
+#define LZ4_ARCH64 0
+#endif
+
+#if defined(__LITTLE_ENDIAN)
+#define LZ4_LITTLE_ENDIAN 1
+#else
+#define LZ4_LITTLE_ENDIAN 0
+#endif
+
+/*-************************************
+ *	Constants
+ **************************************/
+#define MINMATCH 4
+
+#define WILDCOPYLENGTH 8
+#define LASTLITERALS 5
+#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
+
+/* Increase this value ==> compression run slower on incompressible data */
+#define LZ4_SKIPTRIGGER 6
+
+#define HASH_UNIT sizeof(size_t)
+
+#define KB (1 << 10)
+#define MB (1 << 20)
+#define GB (1U << 30)
+
+#define MAXD_LOG 16
+#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
+#define STEPSIZE sizeof(size_t)
+
+#define ML_BITS	4
+#define ML_MASK	((1U << ML_BITS) - 1)
+#define RUN_BITS (8 - ML_BITS)
+#define RUN_MASK ((1U << RUN_BITS) - 1)
+
+/*-************************************
+ *	Reading and writing into memory
+ **************************************/
+static FORCE_INLINE U16 LZ4_read16(const void *ptr)
+{
+	return get_unaligned((const U16 *)ptr);
+}
+
+static FORCE_INLINE U32 LZ4_read32(const void *ptr)
+{
+	return get_unaligned((const U32 *)ptr);
+}
+
+static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
+{
+	return get_unaligned((const size_t *)ptr);
+}
+
+static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
+{
+	put_unaligned(value, (U16 *)memPtr);
+}
+
+static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
+{
+	put_unaligned(value, (U32 *)memPtr);
+}
+
+static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
+{
+	return get_unaligned_le16(memPtr);
+}
+
+static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
+{
+	return put_unaligned_le16(value, memPtr);
+}
+
+static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
+{
+#if LZ4_ARCH64
+	U64 a = get_unaligned((const U64 *)src);
+
+	put_unaligned(a, (U64 *)dst);
+#else
+	U32 a = get_unaligned((const U32 *)src);
+	U32 b = get_unaligned((const U32 *)src + 1);
+
+	put_unaligned(a, (U32 *)dst);
+	put_unaligned(b, (U32 *)dst + 1);
+#endif
+}
+
+/*
+ * customized variant of memcpy,
+ * which can overwrite up to 7 bytes beyond dstEnd
+ */
+static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
+	const void *srcPtr, void *dstEnd)
+{
+	BYTE *d = (BYTE *)dstPtr;
+	const BYTE *s = (const BYTE *)srcPtr;
+	BYTE *const e = (BYTE *)dstEnd;
+
+	do {
+		LZ4_copy8(d, s);
+		d += 8;
+		s += 8;
+	} while (d < e);
+}
+
+static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
+{
+#if LZ4_LITTLE_ENDIAN
+	return __ffs(val) >> 3;
+#else
+	return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
+#endif
+}
+
+static FORCE_INLINE unsigned int LZ4_count(
+	const BYTE *pIn,
+	const BYTE *pMatch,
+	const BYTE *pInLimit)
+{
+	const BYTE *const pStart = pIn;
+
+	while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
+		size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
+
+		if (!diff) {
+			pIn += STEPSIZE;
+			pMatch += STEPSIZE;
+			continue;
+		}
+
+		pIn += LZ4_NbCommonBytes(diff);
+
+		return (unsigned int)(pIn - pStart);
+	}
+
+#if LZ4_ARCH64
+	if ((pIn < (pInLimit - 3))
+		&& (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
+		pIn += 4;
+		pMatch += 4;
+	}
+#endif
+
+	if ((pIn < (pInLimit - 1))
+		&& (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
+		pIn += 2;
+		pMatch += 2;
+	}
+
+	if ((pIn < pInLimit) && (*pMatch == *pIn))
+		pIn++;
+
+	return (unsigned int)(pIn - pStart);
+}
+
+typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
+typedef enum { byPtr, byU32, byU16 } tableType_t;
+
+typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
+typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
+
+typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
+typedef enum { full = 0, partial = 1 } earlyEnd_directive;
+
+#endif
diff --git a/drivers/staging/erofs/unzip_lz4.c b/drivers/staging/erofs/unzip_lz4.c
new file mode 100644
index 0000000..b1ea23f
--- /dev/null
+++ b/drivers/staging/erofs/unzip_lz4.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+/*
+ * linux/drivers/staging/erofs/unzip_lz4.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * Original code taken from 'linux/lib/lz4/lz4_decompress.c'
+ */
+
+/*
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011 - 2016, Yann Collet.
+ * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *	* Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ *	* Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * You can contact the author at :
+ *	- LZ4 homepage : http://www.lz4.org
+ *	- LZ4 source repository : https://github.com/lz4/lz4
+ *
+ *	Changed for kernel usage by:
+ *	Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
+ */
+#include "internal.h"
+#include <asm/unaligned.h>
+#include "lz4defs.h"
+
+/*
+ * no public solution to solve our requirement yet.
+ * see: <required buffer size for LZ4_decompress_safe_partial>
+ *      https://groups.google.com/forum/#!topic/lz4c/_3kkz5N6n00
+ */
+static FORCE_INLINE int customized_lz4_decompress_safe_partial(
+	const void * const source,
+	void * const dest,
+	int inputSize,
+	int outputSize)
+{
+	/* Local Variables */
+	const BYTE *ip = (const BYTE *) source;
+	const BYTE * const iend = ip + inputSize;
+
+	BYTE *op = (BYTE *) dest;
+	BYTE * const oend = op + outputSize;
+	BYTE *cpy;
+
+	static const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
+	static const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
+
+	/* Empty output buffer */
+	if (unlikely(outputSize == 0))
+		return ((inputSize == 1) && (*ip == 0)) ? 0 : -1;
+
+	/* Main Loop : decode sequences */
+	while (1) {
+		size_t length;
+		const BYTE *match;
+		size_t offset;
+
+		/* get literal length */
+		unsigned int const token = *ip++;
+
+		length = token>>ML_BITS;
+
+		if (length == RUN_MASK) {
+			unsigned int s;
+
+			do {
+				s = *ip++;
+				length += s;
+			} while ((ip < iend - RUN_MASK) & (s == 255));
+
+			if (unlikely((size_t)(op + length) < (size_t)(op))) {
+				/* overflow detection */
+				goto _output_error;
+			}
+			if (unlikely((size_t)(ip + length) < (size_t)(ip))) {
+				/* overflow detection */
+				goto _output_error;
+			}
+		}
+
+		/* copy literals */
+		cpy = op + length;
+		if ((cpy > oend - WILDCOPYLENGTH) ||
+			(ip + length > iend - (2 + 1 + LASTLITERALS))) {
+			if (cpy > oend) {
+				memcpy(op, ip, length = oend - op);
+				op += length;
+				break;
+			}
+
+			if (unlikely(ip + length > iend)) {
+				/*
+				 * Error :
+				 * read attempt beyond
+				 * end of input buffer
+				 */
+				goto _output_error;
+			}
+
+			memcpy(op, ip, length);
+			ip += length;
+			op += length;
+
+			if (ip > iend - 2)
+				break;
+			/* Necessarily EOF, due to parsing restrictions */
+			/* break; */
+		} else {
+			LZ4_wildCopy(op, ip, cpy);
+			ip += length;
+			op = cpy;
+		}
+
+		/* get offset */
+		offset = LZ4_readLE16(ip);
+		ip += 2;
+		match = op - offset;
+
+		if (unlikely(match < (const BYTE *)dest)) {
+			/* Error : offset outside buffers */
+			goto _output_error;
+		}
+
+		/* get matchlength */
+		length = token & ML_MASK;
+		if (length == ML_MASK) {
+			unsigned int s;
+
+			do {
+				s = *ip++;
+
+				if (ip > iend - LASTLITERALS)
+					goto _output_error;
+
+				length += s;
+			} while (s == 255);
+
+			if (unlikely((size_t)(op + length) < (size_t)op)) {
+				/* overflow detection */
+				goto _output_error;
+			}
+		}
+
+		length += MINMATCH;
+
+		/* copy match within block */
+		cpy = op + length;
+
+		if (unlikely(cpy >= oend - WILDCOPYLENGTH)) {
+			if (cpy >= oend) {
+				while (op < oend)
+					*op++ = *match++;
+				break;
+			}
+			goto __match;
+		}
+
+		/* costs ~1%; silence an msan warning when offset == 0 */
+		LZ4_write32(op, (U32)offset);
+
+		if (unlikely(offset < 8)) {
+			const int dec64 = dec64table[offset];
+
+			op[0] = match[0];
+			op[1] = match[1];
+			op[2] = match[2];
+			op[3] = match[3];
+			match += dec32table[offset];
+			memcpy(op + 4, match, 4);
+			match -= dec64;
+		} else {
+			LZ4_copy8(op, match);
+			match += 8;
+		}
+
+		op += 8;
+
+		if (unlikely(cpy > oend - 12)) {
+			BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
+
+			if (op < oCopyLimit) {
+				LZ4_wildCopy(op, match, oCopyLimit);
+				match += oCopyLimit - op;
+				op = oCopyLimit;
+			}
+__match:
+			while (op < cpy)
+				*op++ = *match++;
+		} else {
+			LZ4_copy8(op, match);
+
+			if (length > 16)
+				LZ4_wildCopy(op + 8, match + 8, cpy);
+		}
+
+		op = cpy; /* correction */
+	}
+	DBG_BUGON((void *)ip - source > inputSize);
+	DBG_BUGON((void *)op - dest > outputSize);
+
+	/* Nb of output bytes decoded */
+	return (int) ((void *)op - dest);
+
+	/* Overflow error detected */
+_output_error:
+	return -ERANGE;
+}
+
+int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret = customized_lz4_decompress_safe_partial(in,
+		out, inlen, outlen);
+
+	if (ret >= 0)
+		return ret;
+
+	/*
+	 * LZ4_decompress_safe will return an error code
+	 * (< 0) if decompression failed
+	 */
+	errln("%s, failed to decompress, in[%p, %zu] outlen[%p, %zu]",
+	      __func__, in, inlen, out, outlen);
+	WARN_ON(1);
+	print_hex_dump(KERN_DEBUG, "raw data [in]: ", DUMP_PREFIX_OFFSET,
+		16, 1, in, inlen, true);
+	print_hex_dump(KERN_DEBUG, "raw data [out]: ", DUMP_PREFIX_OFFSET,
+		16, 1, out, outlen, true);
+	return -EIO;
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 19/25] staging: erofs: add a generic z_erofs VLE decompressor
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (17 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 18/25] staging: erofs: introduce a customized LZ4 decompression Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 20/25] staging: erofs: introduce superblock registration Gao Xiang
                     ` (7 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

Currently, this patch only simply implements LZ4
decompressor due to its development priority.

In the future, erofs will support more compression
algorithm and format other than LZ4, thus a generic
decompressor interface will be needed.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Kconfig         |  14 +++
 drivers/staging/erofs/Makefile        |   2 +-
 drivers/staging/erofs/internal.h      |   5 +
 drivers/staging/erofs/unzip_vle.h     |  35 ++++++
 drivers/staging/erofs/unzip_vle_lz4.c | 209 ++++++++++++++++++++++++++++++++++
 5 files changed, 264 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/erofs/unzip_vle.h
 create mode 100644 drivers/staging/erofs/unzip_vle_lz4.c

diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index 63bec70..b55ce1c 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -87,3 +87,17 @@ config EROFS_FS_ZIP
 
 	  If you don't want to use compression feature, say N.
 
+config EROFS_FS_CLUSTER_PAGE_LIMIT
+	int "EROFS Cluster Pages Hard Limit"
+	depends on EROFS_FS_ZIP
+	range 1 256
+	default "1"
+	help
+	  Indicates VLE compressed pages hard limit of a
+	  compressed cluster.
+
+	  For example, if files of a image are compressed
+	  into 8k-unit, the hard limit should not be less
+	  than 2. Otherwise, the image cannot be mounted
+	  correctly on this kernel.
+
diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index e409637..9a766eb 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -9,5 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
 ccflags-y += -I$(src)/include
 erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
 erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
-erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o unzip_vle_lz4.o
 
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 6a0f045..e61d417 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -161,6 +161,11 @@ static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
 
 #define ROOT_NID(sb)		((sb)->root_nid)
 
+#ifdef CONFIG_EROFS_FS_ZIP
+/* hard limit of pages per compressed cluster */
+#define Z_EROFS_CLUSTER_MAX_PAGES       (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
+#endif
+
 typedef u64 erofs_off_t;
 
 /* data type for filesystem-wide blocks number */
diff --git a/drivers/staging/erofs/unzip_vle.h b/drivers/staging/erofs/unzip_vle.h
new file mode 100644
index 0000000..b34f5bc
--- /dev/null
+++ b/drivers/staging/erofs/unzip_vle.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/drivers/staging/erofs/unzip_vle.h
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#ifndef __EROFS_FS_UNZIP_VLE_H
+#define __EROFS_FS_UNZIP_VLE_H
+
+#include "internal.h"
+
+#define Z_EROFS_VLE_INLINE_PAGEVECS     3
+
+/* unzip_vle_lz4.c */
+extern int z_erofs_vle_plain_copy(struct page **compressed_pages,
+	unsigned clusterpages, struct page **pages,
+	unsigned nr_pages, unsigned short pageofs);
+
+extern int z_erofs_vle_unzip_fast_percpu(struct page **compressed_pages,
+	unsigned clusterpages, struct page **pages,
+	unsigned outlen, unsigned short pageofs,
+	void (*endio)(struct page *));
+
+extern int z_erofs_vle_unzip_vmap(struct page **compressed_pages,
+	unsigned clusterpages, void *vaddr, unsigned llen,
+	unsigned short pageofs, bool overlapped);
+
+#endif
+
diff --git a/drivers/staging/erofs/unzip_vle_lz4.c b/drivers/staging/erofs/unzip_vle_lz4.c
new file mode 100644
index 0000000..f5b665f
--- /dev/null
+++ b/drivers/staging/erofs/unzip_vle_lz4.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/drivers/staging/erofs/unzip_vle_lz4.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25@huawei.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of the Linux
+ * distribution for more details.
+ */
+#include "unzip_vle.h"
+
+#if Z_EROFS_CLUSTER_MAX_PAGES > Z_EROFS_VLE_INLINE_PAGEVECS
+#define EROFS_PERCPU_NR_PAGES   Z_EROFS_CLUSTER_MAX_PAGES
+#else
+#define EROFS_PERCPU_NR_PAGES   Z_EROFS_VLE_INLINE_PAGEVECS
+#endif
+
+static struct {
+	char data[PAGE_SIZE * EROFS_PERCPU_NR_PAGES];
+} erofs_pcpubuf[NR_CPUS];
+
+int z_erofs_vle_plain_copy(struct page **compressed_pages,
+			   unsigned clusterpages,
+			   struct page **pages,
+			   unsigned nr_pages,
+			   unsigned short pageofs)
+{
+	unsigned i, j;
+	void *src = NULL;
+	const unsigned righthalf = PAGE_SIZE - pageofs;
+	char *percpu_data;
+	bool mirrored[Z_EROFS_CLUSTER_MAX_PAGES] = { 0 };
+
+	preempt_disable();
+	percpu_data = erofs_pcpubuf[smp_processor_id()].data;
+
+	j = 0;
+	for (i = 0; i < nr_pages; j = i++) {
+		struct page *page = pages[i];
+		void *dst;
+
+		if (page == NULL) {
+			if (src != NULL) {
+				if (!mirrored[j])
+					kunmap_atomic(src);
+				src = NULL;
+			}
+			continue;
+		}
+
+		dst = kmap_atomic(page);
+
+		for (; j < clusterpages; ++j) {
+			if (compressed_pages[j] != page)
+				continue;
+
+			BUG_ON(mirrored[j]);
+			memcpy(percpu_data + j * PAGE_SIZE, dst, PAGE_SIZE);
+			mirrored[j] = true;
+			break;
+		}
+
+		if (i) {
+			if (src == NULL)
+				src = mirrored[i-1] ?
+					percpu_data + (i-1) * PAGE_SIZE :
+					kmap_atomic(compressed_pages[i-1]);
+
+			memcpy(dst, src + righthalf, pageofs);
+
+			if (!mirrored[i-1])
+				kunmap_atomic(src);
+
+			if (unlikely(i >= clusterpages)) {
+				kunmap_atomic(dst);
+				break;
+			}
+		}
+
+		if (!righthalf)
+			src = NULL;
+		else {
+			src = mirrored[i] ? percpu_data + i * PAGE_SIZE :
+				kmap_atomic(compressed_pages[i]);
+
+			memcpy(dst + pageofs, src, righthalf);
+		}
+
+		kunmap_atomic(dst);
+	}
+
+	if (src != NULL && !mirrored[j])
+		kunmap_atomic(src);
+
+	preempt_enable();
+	return 0;
+}
+
+extern int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen);
+
+int z_erofs_vle_unzip_fast_percpu(struct page **compressed_pages,
+				  unsigned clusterpages,
+				  struct page **pages,
+				  unsigned outlen,
+				  unsigned short pageofs,
+				  void (*endio)(struct page *))
+{
+	void *vin, *vout;
+	unsigned nr_pages, i, j;
+	int ret;
+
+	if (outlen + pageofs > EROFS_PERCPU_NR_PAGES * PAGE_SIZE)
+		return -ENOTSUPP;
+
+	nr_pages = DIV_ROUND_UP(outlen + pageofs, PAGE_SIZE);
+
+	if (clusterpages == 1)
+		vin = kmap_atomic(compressed_pages[0]);
+	else
+		vin = erofs_vmap(compressed_pages, clusterpages);
+
+	preempt_disable();
+	vout = erofs_pcpubuf[smp_processor_id()].data;
+
+	ret = z_erofs_unzip_lz4(vin, vout + pageofs,
+		clusterpages * PAGE_SIZE, outlen);
+
+	if (ret >= 0) {
+		outlen = ret;
+		ret = 0;
+	}
+
+	for (i = 0; i < nr_pages; ++i) {
+		j = min((unsigned)PAGE_SIZE - pageofs, outlen);
+
+		if (pages[i] != NULL) {
+			if (ret < 0)
+				SetPageError(pages[i]);
+			else if (clusterpages == 1 && pages[i] == compressed_pages[0])
+				memcpy(vin + pageofs, vout + pageofs, j);
+			else {
+				void *dst = kmap_atomic(pages[i]);
+
+				memcpy(dst + pageofs, vout + pageofs, j);
+				kunmap_atomic(dst);
+			}
+			endio(pages[i]);
+		}
+		vout += PAGE_SIZE;
+		outlen -= j;
+		pageofs = 0;
+	}
+	preempt_enable();
+
+	if (clusterpages == 1)
+		kunmap_atomic(vin);
+	else
+		erofs_vunmap(vin, clusterpages);
+
+	return ret;
+}
+
+int z_erofs_vle_unzip_vmap(struct page **compressed_pages,
+			   unsigned clusterpages,
+			   void *vout,
+			   unsigned llen,
+			   unsigned short pageofs,
+			   bool overlapped)
+{
+	void *vin;
+	unsigned i;
+	int ret;
+
+	if (overlapped) {
+		preempt_disable();
+		vin = erofs_pcpubuf[smp_processor_id()].data;
+
+		for (i = 0; i < clusterpages; ++i) {
+			void *t = kmap_atomic(compressed_pages[i]);
+
+			memcpy(vin + PAGE_SIZE *i, t, PAGE_SIZE);
+			kunmap_atomic(t);
+		}
+	} else if (clusterpages == 1)
+		vin = kmap_atomic(compressed_pages[0]);
+	else {
+		vin = erofs_vmap(compressed_pages, clusterpages);
+	}
+
+	ret = z_erofs_unzip_lz4(vin, vout + pageofs,
+		clusterpages * PAGE_SIZE, llen);
+	if (ret > 0)
+		ret = 0;
+
+	if (!overlapped) {
+		if (clusterpages == 1)
+			kunmap_atomic(vin);
+		else {
+			erofs_vunmap(vin, clusterpages);
+		}
+	} else
+		preempt_enable();
+
+	return ret;
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 20/25] staging: erofs: introduce superblock registration
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (18 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 19/25] staging: erofs: add a generic z_erofs VLE decompressor Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 21/25] staging: erofs: introduce erofs shrinker Gao Xiang
                     ` (6 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

In order to introducing shrinker solution for erofs,
let's manage all mounted erofs instances at first.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/internal.h |  6 ++++++
 drivers/staging/erofs/super.c    |  4 ++++
 drivers/staging/erofs/utils.c    | 17 +++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index e61d417..18e7b9c 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -64,6 +64,9 @@ struct erofs_fault_info {
 typedef u64 erofs_nid_t;
 
 struct erofs_sb_info {
+	/* list for all registered superblocks, mainly for shrinker */
+	struct list_head list;
+
 	u32 blocks;
 	u32 meta_blkaddr;
 #ifdef CONFIG_EROFS_FS_XATTR
@@ -410,6 +413,9 @@ static inline void erofs_vunmap(const void *mem, unsigned int count)
 /* utils.c */
 extern struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
 
+extern void erofs_register_super(struct super_block *sb);
+extern void erofs_unregister_super(struct super_block *sb);
+
 #ifndef lru_to_page
 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 #endif
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 054375d..f455d71 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -326,6 +326,8 @@ static int erofs_read_super(struct super_block *sb,
 	snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
 	sbi->dev_name[PATH_MAX - 1] = '\0';
 
+	erofs_register_super(sb);
+
 	/*
 	 * We already have a positive dentry, which was instantiated
 	 * by d_make_root. Just need to d_rehash it.
@@ -373,6 +375,8 @@ static void erofs_put_super(struct super_block *sb)
 	infoln("unmounted for %s", sbi->dev_name);
 	__putname(sbi->dev_name);
 
+	erofs_unregister_super(sb);
+
 	kfree(sbi);
 	sb->s_fs_info = NULL;
 }
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index 3dec4f8..6748def 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -29,3 +29,20 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
 	return page;
 }
 
+static DEFINE_MUTEX(erofs_sb_list_lock);
+static LIST_HEAD(erofs_sb_list);
+
+void erofs_register_super(struct super_block *sb)
+{
+	mutex_lock(&erofs_sb_list_lock);
+	list_add(&EROFS_SB(sb)->list, &erofs_sb_list);
+	mutex_unlock(&erofs_sb_list_lock);
+}
+
+void erofs_unregister_super(struct super_block *sb)
+{
+	mutex_lock(&erofs_sb_list_lock);
+	list_del(&EROFS_SB(sb)->list);
+	mutex_unlock(&erofs_sb_list_lock);
+}
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 21/25] staging: erofs: introduce erofs shrinker
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (19 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 20/25] staging: erofs: introduce superblock registration Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 22/25] staging: erofs: introduce workstation for decompression Gao Xiang
                     ` (5 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch adds a dedicated shrinker targeting to free unneeded
memory consumed by a number of erofs in-memory data structures.

Like F2FS and UBIFS, it also adds:
  - sbi->umount_mutex to avoid races on shrinker and put_super
  - sbi->shrinker_run_no to not revisit recently scaned objects

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/internal.h |  7 ++++
 drivers/staging/erofs/super.c    | 15 +++++++
 drivers/staging/erofs/utils.c    | 85 +++++++++++++++++++++++++++++++++++++---
 3 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 18e7b9c..42455f0 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -66,6 +66,7 @@ struct erofs_fault_info {
 struct erofs_sb_info {
 	/* list for all registered superblocks, mainly for shrinker */
 	struct list_head list;
+	struct mutex umount_mutex;
 
 	u32 blocks;
 	u32 meta_blkaddr;
@@ -93,6 +94,7 @@ struct erofs_sb_info {
 	char *dev_name;
 
 	unsigned int mount_opt;
+	unsigned int shrinker_run_no;
 
 #ifdef CONFIG_EROFS_FAULT_INJECTION
 	struct erofs_fault_info fault_info;	/* For fault injection */
@@ -416,6 +418,11 @@ static inline void erofs_vunmap(const void *mem, unsigned int count)
 extern void erofs_register_super(struct super_block *sb);
 extern void erofs_unregister_super(struct super_block *sb);
 
+extern unsigned long erofs_shrink_count(struct shrinker *shrink,
+	struct shrink_control *sc);
+extern unsigned long erofs_shrink_scan(struct shrinker *shrink,
+	struct shrink_control *sc);
+
 #ifndef lru_to_page
 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 #endif
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index f455d71..ef85884 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -375,7 +375,9 @@ static void erofs_put_super(struct super_block *sb)
 	infoln("unmounted for %s", sbi->dev_name);
 	__putname(sbi->dev_name);
 
+	mutex_lock(&sbi->umount_mutex);
 	erofs_unregister_super(sb);
+	mutex_unlock(&sbi->umount_mutex);
 
 	kfree(sbi);
 	sb->s_fs_info = NULL;
@@ -415,6 +417,12 @@ static void erofs_kill_sb(struct super_block *sb)
 	kill_block_super(sb);
 }
 
+static struct shrinker erofs_shrinker_info = {
+	.scan_objects = erofs_shrink_scan,
+	.count_objects = erofs_shrink_count,
+	.seeks = DEFAULT_SEEKS,
+};
+
 static struct file_system_type erofs_fs_type = {
 	.owner          = THIS_MODULE,
 	.name           = "erofs",
@@ -435,6 +443,10 @@ static int __init erofs_module_init(void)
 	if (err)
 		goto icache_err;
 
+	err = register_shrinker(&erofs_shrinker_info);
+	if (err)
+		goto shrinker_err;
+
 	err = register_filesystem(&erofs_fs_type);
 	if (err)
 		goto fs_err;
@@ -443,6 +455,8 @@ static int __init erofs_module_init(void)
 	return 0;
 
 fs_err:
+	unregister_shrinker(&erofs_shrinker_info);
+shrinker_err:
 	erofs_exit_inode_cache();
 icache_err:
 	return err;
@@ -451,6 +465,7 @@ static int __init erofs_module_init(void)
 static void __exit erofs_module_exit(void)
 {
 	unregister_filesystem(&erofs_fs_type);
+	unregister_shrinker(&erofs_shrinker_info);
 	erofs_exit_inode_cache();
 	infoln("successfully finalize erofs");
 }
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index 6748def..c1d83ce 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -29,20 +29,93 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
 	return page;
 }
 
-static DEFINE_MUTEX(erofs_sb_list_lock);
+
+/* protected by 'erofs_sb_list_lock' */
+static unsigned int shrinker_run_no;
+
+/* protects the mounted 'erofs_sb_list' */
+static DEFINE_SPINLOCK(erofs_sb_list_lock);
 static LIST_HEAD(erofs_sb_list);
 
+/* global shrink count (for all mounted EROFS instances) */
+static atomic_long_t erofs_global_shrink_cnt;
+
 void erofs_register_super(struct super_block *sb)
 {
-	mutex_lock(&erofs_sb_list_lock);
-	list_add(&EROFS_SB(sb)->list, &erofs_sb_list);
-	mutex_unlock(&erofs_sb_list_lock);
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+
+	mutex_init(&sbi->umount_mutex);
+
+	spin_lock(&erofs_sb_list_lock);
+	list_add(&sbi->list, &erofs_sb_list);
+	spin_unlock(&erofs_sb_list_lock);
 }
 
 void erofs_unregister_super(struct super_block *sb)
 {
-	mutex_lock(&erofs_sb_list_lock);
+	spin_lock(&erofs_sb_list_lock);
 	list_del(&EROFS_SB(sb)->list);
-	mutex_unlock(&erofs_sb_list_lock);
+	spin_unlock(&erofs_sb_list_lock);
+}
+
+unsigned long erofs_shrink_count(struct shrinker *shrink,
+				 struct shrink_control *sc)
+{
+	return atomic_long_read(&erofs_global_shrink_cnt);
+}
+
+unsigned long erofs_shrink_scan(struct shrinker *shrink,
+				struct shrink_control *sc)
+{
+	struct erofs_sb_info *sbi;
+	struct list_head *p;
+
+	unsigned long nr = sc->nr_to_scan;
+	unsigned int run_no;
+	unsigned long freed = 0;
+
+	spin_lock(&erofs_sb_list_lock);
+	do
+		run_no = ++shrinker_run_no;
+	while (run_no == 0);
+
+	/* Iterate over all mounted superblocks and try to shrink them */
+	p = erofs_sb_list.next;
+	while (p != &erofs_sb_list) {
+		sbi = list_entry(p, struct erofs_sb_info, list);
+
+		/*
+		 * We move the ones we do to the end of the list, so we stop
+		 * when we see one we have already done.
+		 */
+		if (sbi->shrinker_run_no == run_no)
+			break;
+
+		if (!mutex_trylock(&sbi->umount_mutex)) {
+			p = p->next;
+			continue;
+		}
+
+		spin_unlock(&erofs_sb_list_lock);
+		sbi->shrinker_run_no = run_no;
+
+		/* add scan handlers here */
+
+		spin_lock(&erofs_sb_list_lock);
+		/* Get the next list element before we move this one */
+		p = p->next;
+
+		/*
+		 * Move this one to the end of the list to provide some
+		 * fairness.
+		 */
+		list_move_tail(&sbi->list, &erofs_sb_list);
+		mutex_unlock(&sbi->umount_mutex);
+
+		if (freed >= nr)
+			break;
+	}
+	spin_unlock(&erofs_sb_list_lock);
+	return freed;
 }
 
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 22/25] staging: erofs: introduce workstation for decompression
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (20 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 21/25] staging: erofs: introduce erofs shrinker Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 23/25] staging: erofs: introduce VLE decompression support Gao Xiang
                     ` (4 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch introduces another concept used by the unzip
subsystem called 'workstation'. It can be seen as a sparse
array that stores pointers pointed to data structures
related to the corresponding physical blocks.

All lookup cases are protected by RCU read lock. Besides,
reference count and spin_lock are also introduced to
manage its lifetime and serialize all update operations.

'workstation' is currently implemented on the in-kernel
radix tree approach for backward compatibility.
With the evolution of linux kernel, it could be migrated
into XArray implementation in the future.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/internal.h | 93 ++++++++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/super.c    |  9 ++++
 drivers/staging/erofs/utils.c    | 81 ++++++++++++++++++++++++++++++++--
 3 files changed, 180 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 42455f0..b07cd7a 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -79,6 +79,9 @@ struct erofs_sb_info {
 #ifdef CONFIG_EROFS_FS_ZIP
 	/* cluster size in bit shift */
 	unsigned char clusterbits;
+
+	/* the dedicated workstation for compression */
+	struct radix_tree_root workstn_tree;
 #endif
 
 	u32 build_time_nsec;
@@ -149,6 +152,96 @@ static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
 #define set_opt(sbi, option)	((sbi)->mount_opt |= EROFS_MOUNT_##option)
 #define test_opt(sbi, option)	((sbi)->mount_opt & EROFS_MOUNT_##option)
 
+#ifdef CONFIG_EROFS_FS_ZIP
+#define erofs_workstn_lock(sbi)         xa_lock(&(sbi)->workstn_tree)
+#define erofs_workstn_unlock(sbi)       xa_unlock(&(sbi)->workstn_tree)
+
+/* basic unit of the workstation of a super_block */
+struct erofs_workgroup {
+	/* the workgroup index in the workstation */
+	pgoff_t index;
+
+	/* overall workgroup reference count */
+	atomic_t refcount;
+};
+
+#define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
+
+static inline bool erofs_workgroup_try_to_freeze(
+	struct erofs_workgroup *grp, int v)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	if (v != atomic_cmpxchg(&grp->refcount,
+		v, EROFS_LOCKED_MAGIC))
+		return false;
+	preempt_disable();
+#else
+	preempt_disable();
+	if (atomic_read(&grp->refcount) != v) {
+		preempt_enable();
+		return false;
+	}
+#endif
+	return true;
+}
+
+static inline void erofs_workgroup_unfreeze(
+	struct erofs_workgroup *grp, int v)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	atomic_set(&grp->refcount, v);
+#endif
+	preempt_enable();
+}
+
+static inline bool erofs_workgroup_get(struct erofs_workgroup *grp, int *ocnt)
+{
+	const int locked = (int)EROFS_LOCKED_MAGIC;
+	int o;
+
+repeat:
+	o = atomic_read(&grp->refcount);
+
+	/* spin if it is temporarily locked at the reclaim path */
+	if (unlikely(o == locked)) {
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+		do
+			cpu_relax();
+		while (atomic_read(&grp->refcount) == locked);
+#endif
+		goto repeat;
+	}
+
+	if (unlikely(o <= 0))
+		return -1;
+
+	if (unlikely(atomic_cmpxchg(&grp->refcount, o, o + 1) != o))
+		goto repeat;
+
+	*ocnt = o;
+	return 0;
+}
+
+#define __erofs_workgroup_get(grp)	atomic_inc(&(grp)->refcount)
+
+extern int erofs_workgroup_put(struct erofs_workgroup *grp);
+
+extern struct erofs_workgroup *erofs_find_workgroup(
+	struct super_block *sb, pgoff_t index, bool *tag);
+
+extern int erofs_register_workgroup(struct super_block *sb,
+	struct erofs_workgroup *grp, bool tag);
+
+extern unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+	unsigned long nr_shrink, bool cleanup);
+
+static inline void erofs_workstation_cleanup_all(struct super_block *sb)
+{
+	erofs_shrink_workstation(EROFS_SB(sb), ~0UL, true);
+}
+
+#endif
+
 /* we strictly follow PAGE_SIZE and no buffer head yet */
 #define LOG_BLOCK_SIZE		PAGE_SHIFT
 
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index ef85884..e155a2b 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -296,6 +296,10 @@ static int erofs_read_super(struct super_block *sb,
 	if (!silent)
 		infoln("root inode @ nid %llu", ROOT_NID(sbi));
 
+#ifdef CONFIG_EROFS_FS_ZIP
+	INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
+#endif
+
 	/* get the root inode */
 	inode = erofs_iget(sb, ROOT_NID(sbi), true);
 	if (IS_ERR(inode)) {
@@ -376,6 +380,11 @@ static void erofs_put_super(struct super_block *sb)
 	__putname(sbi->dev_name);
 
 	mutex_lock(&sbi->umount_mutex);
+
+#ifdef CONFIG_EROFS_FS_ZIP
+	erofs_workstation_cleanup_all(sb);
+#endif
+
 	erofs_unregister_super(sb);
 	mutex_unlock(&sbi->umount_mutex);
 
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index c1d83ce..0d4eae2 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -29,6 +29,83 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
 	return page;
 }
 
+/* global shrink count (for all mounted EROFS instances) */
+static atomic_long_t erofs_global_shrink_cnt;
+
+#ifdef CONFIG_EROFS_FS_ZIP
+
+/* radix_tree and the future XArray both don't use tagptr_t yet */
+struct erofs_workgroup *erofs_find_workgroup(
+	struct super_block *sb, pgoff_t index, bool *tag)
+{
+	struct erofs_sb_info *sbi = EROFS_SB(sb);
+	struct erofs_workgroup *grp;
+	int oldcount;
+
+repeat:
+	rcu_read_lock();
+	grp = radix_tree_lookup(&sbi->workstn_tree, index);
+	if (grp != NULL) {
+		*tag = radix_tree_exceptional_entry(grp);
+		grp = (void *)((unsigned long)grp &
+			~RADIX_TREE_EXCEPTIONAL_ENTRY);
+
+		if (erofs_workgroup_get(grp, &oldcount)) {
+			/* prefer to relax rcu read side */
+			rcu_read_unlock();
+			goto repeat;
+		}
+
+		/* decrease refcount added by erofs_workgroup_put */
+		if (unlikely(oldcount == 1))
+			atomic_long_dec(&erofs_global_shrink_cnt);
+		BUG_ON(index != grp->index);
+	}
+	rcu_read_unlock();
+	return grp;
+}
+
+int erofs_register_workgroup(struct super_block *sb,
+			     struct erofs_workgroup *grp,
+			     bool tag)
+{
+	struct erofs_sb_info *sbi;
+	int err;
+
+	/* grp->refcount should not < 1 */
+	BUG_ON(!atomic_read(&grp->refcount));
+
+	err = radix_tree_preload(GFP_NOFS);
+	if (err)
+		return err;
+
+	sbi = EROFS_SB(sb);
+	erofs_workstn_lock(sbi);
+
+	if (tag)
+		grp = (void *)((unsigned long)grp |
+			1UL << RADIX_TREE_EXCEPTIONAL_SHIFT);
+
+	err = radix_tree_insert(&sbi->workstn_tree,
+		grp->index, grp);
+
+	if (!err) {
+		__erofs_workgroup_get(grp);
+	}
+
+	erofs_workstn_unlock(sbi);
+	radix_tree_preload_end();
+	return err;
+}
+
+unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+				       unsigned long nr_shrink,
+				       bool cleanup)
+{
+	return 0;
+}
+
+#endif
 
 /* protected by 'erofs_sb_list_lock' */
 static unsigned int shrinker_run_no;
@@ -37,9 +114,6 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
 static DEFINE_SPINLOCK(erofs_sb_list_lock);
 static LIST_HEAD(erofs_sb_list);
 
-/* global shrink count (for all mounted EROFS instances) */
-static atomic_long_t erofs_global_shrink_cnt;
-
 void erofs_register_super(struct super_block *sb)
 {
 	struct erofs_sb_info *sbi = EROFS_SB(sb);
@@ -112,6 +186,7 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
 		list_move_tail(&sbi->list, &erofs_sb_list);
 		mutex_unlock(&sbi->umount_mutex);
 
+		freed += erofs_shrink_workstation(sbi, nr, false);
 		if (freed >= nr)
 			break;
 	}
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 23/25] staging: erofs: introduce VLE decompression support
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (21 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 22/25] staging: erofs: introduce workstation for decompression Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 24/25] staging: erofs: introduce cached decompression Gao Xiang
                     ` (3 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch introduces the basic in-place VLE decompression
implementation for the erofs file system.

Compared with fixed-sized input compression, it implements
what we call 'the variable-length extent compression' which
specifies the same output size for each compression block
to make the full use of IO bandwidth (which means almost
all data from block device can be directly used for decomp-
ression), improve the real (rather than just via data caching,
which costs more memory) random read and keep the relatively
lower compression ratios (it saves more storage space than
fixed-sized input compression which is also configured with
the same input block size), as illustrated below:

        |---  variable-length extent ---|------ VLE ------|---  VLE ---|
         /> clusterofs                  /> clusterofs     /> clusterofs /> clusterofs
   ++---|-------++-----------++---------|-++-----------++-|---------++-|
...||   |       ||           ||         | ||           || |         || | ... original data
   ++---|-------++-----------++---------|-++-----------++-|---------++-|
   ++->cluster<-++->cluster<-++->cluster<-++->cluster<-++->cluster<-++
        size         size         size         size         size
         \                             /                 /            /
          \                      /              /            /
           \               /            /            /
            ++-----------++-----------++-----------++
        ... ||           ||           ||           || ... compressed clusters
            ++-----------++-----------++-----------++
            ++->cluster<-++->cluster<-++->cluster<-++
                 size         size         size

The main point of 'in-place' refers to the decompression mode:
Instead of allocating independent compressed pages and data
structures, it reuses the allocated file cache pages at most
to store its compressed data and the corresponding pagevec in
a time-sharing approach by default, which will be useful for
low memory scenario.

In the end, unlike the other filesystems with (de)compression
support using a relatively large compression block size, which
reads and decompresses >= 128KB at once, and gains a more
good-looking random read (In fact it collects small random reads
into large sequential reads and caches all decompressed data
in memory, but it is unacceptable especially for embedded devices
with limited memory, and it is not the real random read), we
select a universal small-sized 4KB compressed cluster, which is
the smallest page size for most architectures, and all compressed
clusters can be read and decompressed independently, which ensures
random read number for all use cases.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/inode.c     |    5 +
 drivers/staging/erofs/internal.h  |    6 +
 drivers/staging/erofs/super.c     |   25 +
 drivers/staging/erofs/unzip_vle.c | 1119 ++++++++++++++++++++++++++++++++++++-
 drivers/staging/erofs/unzip_vle.h |  204 +++++++
 drivers/staging/erofs/utils.c     |   61 +-
 6 files changed, 1418 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index 613c977..fbf6ff2 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -210,7 +210,12 @@ static int fill_inode(struct inode *inode, int isdir)
 		}
 
 		if (is_inode_layout_compression(inode)) {
+#ifdef CONFIG_EROFS_FS_ZIP
+			inode->i_mapping->a_ops =
+				&z_erofs_vle_normalaccess_aops;
+#else
 			err = -ENOTSUPP;
+#endif
 			goto out_unlock;
 		}
 
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index b07cd7a..3adec7d 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -262,6 +262,9 @@ static inline void erofs_workstation_cleanup_all(struct super_block *sb)
 #ifdef CONFIG_EROFS_FS_ZIP
 /* hard limit of pages per compressed cluster */
 #define Z_EROFS_CLUSTER_MAX_PAGES       (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
+
+/* page count of a compressed cluster */
+#define erofs_clusterpages(sbi)         ((1 << (sbi)->clusterbits) / PAGE_SIZE)
 #endif
 
 typedef u64 erofs_off_t;
@@ -340,6 +343,9 @@ static inline bool is_inode_layout_inline(struct inode *inode)
 extern const struct file_operations erofs_dir_fops;
 
 extern const struct address_space_operations erofs_raw_access_aops;
+#ifdef CONFIG_EROFS_FS_ZIP
+extern const struct address_space_operations z_erofs_vle_normalaccess_aops;
+#endif
 
 /*
  * Logical to physical block mapping, used by erofs_map_blocks()
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index e155a2b..2bd433a 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -115,6 +115,13 @@ static int superblock_read(struct super_block *sb)
 	sbi->xattr_blkaddr = le32_to_cpu(layout->xattr_blkaddr);
 #endif
 	sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1;
+#ifdef CONFIG_EROFS_FS_ZIP
+	sbi->clusterbits = 12;
+
+	if (1 << (sbi->clusterbits - 12) > Z_EROFS_CLUSTER_MAX_PAGES)
+		errln("clusterbits %u is not supported on this kernel",
+			sbi->clusterbits);
+#endif
 
 	sbi->root_nid = le16_to_cpu(layout->root_nid);
 	sbi->inos = le64_to_cpu(layout->inos);
@@ -441,6 +448,11 @@ static void erofs_kill_sb(struct super_block *sb)
 };
 MODULE_ALIAS_FS("erofs");
 
+#ifdef CONFIG_EROFS_FS_ZIP
+extern int z_erofs_init_zip_subsystem(void);
+extern void z_erofs_exit_zip_subsystem(void);
+#endif
+
 static int __init erofs_module_init(void)
 {
 	int err;
@@ -456,6 +468,12 @@ static int __init erofs_module_init(void)
 	if (err)
 		goto shrinker_err;
 
+#ifdef CONFIG_EROFS_FS_ZIP
+	err = z_erofs_init_zip_subsystem();
+	if (err)
+		goto zip_err;
+#endif
+
 	err = register_filesystem(&erofs_fs_type);
 	if (err)
 		goto fs_err;
@@ -464,6 +482,10 @@ static int __init erofs_module_init(void)
 	return 0;
 
 fs_err:
+#ifdef CONFIG_EROFS_FS_ZIP
+	z_erofs_exit_zip_subsystem();
+zip_err:
+#endif
 	unregister_shrinker(&erofs_shrinker_info);
 shrinker_err:
 	erofs_exit_inode_cache();
@@ -474,6 +496,9 @@ static int __init erofs_module_init(void)
 static void __exit erofs_module_exit(void)
 {
 	unregister_filesystem(&erofs_fs_type);
+#ifdef CONFIG_EROFS_FS_ZIP
+	z_erofs_exit_zip_subsystem();
+#endif
 	unregister_shrinker(&erofs_shrinker_info);
 	erofs_exit_inode_cache();
 	infoln("successfully finalize erofs");
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 329cbe4..f0ead60 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -10,7 +10,1124 @@
  * License.  See the file COPYING in the main directory of the Linux
  * distribution for more details.
  */
-#include "internal.h"
+#include "unzip_vle.h"
+#include <linux/prefetch.h>
+
+static struct workqueue_struct *z_erofs_workqueue __read_mostly;
+static struct kmem_cache *z_erofs_workgroup_cachep __read_mostly;
+
+void z_erofs_exit_zip_subsystem(void)
+{
+	BUG_ON(z_erofs_workqueue == NULL);
+	BUG_ON(z_erofs_workgroup_cachep == NULL);
+
+	destroy_workqueue(z_erofs_workqueue);
+	kmem_cache_destroy(z_erofs_workgroup_cachep);
+}
+
+static inline int init_unzip_workqueue(void)
+{
+	const unsigned onlinecpus = num_possible_cpus();
+
+	/*
+	 * we don't need too many threads, limiting threads
+	 * could improve scheduling performance.
+	 */
+	z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
+		WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
+		onlinecpus + onlinecpus / 4);
+
+	return z_erofs_workqueue != NULL ? 0 : -ENOMEM;
+}
+
+int z_erofs_init_zip_subsystem(void)
+{
+	z_erofs_workgroup_cachep =
+		kmem_cache_create("erofs_compress",
+		Z_EROFS_WORKGROUP_SIZE, 0,
+		SLAB_RECLAIM_ACCOUNT, NULL);
+
+	if (z_erofs_workgroup_cachep != NULL) {
+		if (!init_unzip_workqueue())
+			return 0;
+
+		kmem_cache_destroy(z_erofs_workgroup_cachep);
+	}
+	return -ENOMEM;
+}
+
+enum z_erofs_vle_work_role {
+	Z_EROFS_VLE_WORK_SECONDARY,
+	Z_EROFS_VLE_WORK_PRIMARY,
+	/*
+	 * The current work has at least been linked with the following
+	 * processed chained works, which means if the processing page
+	 * is the tail partial page of the work, the current work can
+	 * safely use the whole page, as illustrated below:
+	 * +--------------+-------------------------------------------+
+	 * |  tail page   |      head page (of the previous work)     |
+	 * +--------------+-------------------------------------------+
+	 *   /\  which belongs to the current work
+	 * [  (*) this page can be used for the current work itself.  ]
+	 */
+	Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED,
+	Z_EROFS_VLE_WORK_MAX
+};
+
+struct z_erofs_vle_work_builder {
+	enum z_erofs_vle_work_role role;
+	/*
+	 * 'hosted = false' means that the current workgroup doesn't belong to
+	 * the owned chained workgroups. In the other words, it is none of our
+	 * business to submit this workgroup.
+	 */
+	bool hosted;
+
+	struct z_erofs_vle_workgroup *grp;
+	struct z_erofs_vle_work *work;
+	struct z_erofs_pagevec_ctor vector;
+
+	/* pages used for reading the compressed data */
+	struct page **compressed_pages;
+	unsigned compressed_deficit;
+};
+
+#define VLE_WORK_BUILDER_INIT()	\
+	{ .work = NULL, .role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED }
+
+/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
+static inline bool try_to_reuse_as_compressed_page(
+	struct z_erofs_vle_work_builder *b,
+	struct page *page)
+{
+	while (b->compressed_deficit) {
+		--b->compressed_deficit;
+		if (NULL == cmpxchg(b->compressed_pages++, NULL, page))
+			return true;
+	}
+
+	return false;
+}
+
+/* callers must be with work->lock held */
+static int z_erofs_vle_work_add_page(
+	struct z_erofs_vle_work_builder *builder,
+	struct page *page,
+	enum z_erofs_page_type type)
+{
+	int ret;
+	bool occupied;
+
+	/* give priority for the compressed data storage */
+	if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY &&
+		type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
+		try_to_reuse_as_compressed_page(builder, page))
+		return 0;
+
+	ret = z_erofs_pagevec_ctor_enqueue(&builder->vector,
+		page, type, &occupied);
+	builder->work->vcnt += (unsigned)ret;
+
+	return ret ? 0 : -EAGAIN;
+}
+
+static inline bool try_to_claim_workgroup(
+	struct z_erofs_vle_workgroup *grp,
+	z_erofs_vle_owned_workgrp_t *owned_head,
+	bool *hosted)
+{
+	DBG_BUGON(*hosted == true);
+
+	/* let's claim these following types of workgroup */
+retry:
+	if (grp->next == Z_EROFS_VLE_WORKGRP_NIL) {
+		/* type 1, nil workgroup */
+		if (Z_EROFS_VLE_WORKGRP_NIL != cmpxchg(&grp->next,
+			Z_EROFS_VLE_WORKGRP_NIL, *owned_head))
+			goto retry;
+
+		*owned_head = grp;
+		*hosted = true;
+	} else if (grp->next == Z_EROFS_VLE_WORKGRP_TAIL) {
+		/*
+		 * type 2, link to the end of a existing open chain,
+		 * be careful that its submission itself is governed
+		 * by the original owned chain.
+		 */
+		if (Z_EROFS_VLE_WORKGRP_TAIL != cmpxchg(&grp->next,
+			Z_EROFS_VLE_WORKGRP_TAIL, *owned_head))
+			goto retry;
+
+		*owned_head = Z_EROFS_VLE_WORKGRP_TAIL;
+	} else
+		return false;	/* :( better luck next time */
+
+	return true;	/* lucky, I am the followee :) */
+}
+
+static struct z_erofs_vle_work *
+z_erofs_vle_work_lookup(struct super_block *sb,
+			pgoff_t idx, unsigned pageofs,
+			struct z_erofs_vle_workgroup **grp_ret,
+			enum z_erofs_vle_work_role *role,
+			z_erofs_vle_owned_workgrp_t *owned_head,
+			bool *hosted)
+{
+	bool tag, primary;
+	struct erofs_workgroup *egrp;
+	struct z_erofs_vle_workgroup *grp;
+	struct z_erofs_vle_work *work;
+
+	egrp = erofs_find_workgroup(sb, idx, &tag);
+	if (egrp == NULL) {
+		*grp_ret = NULL;
+		return NULL;
+	}
+
+	*grp_ret = grp = container_of(egrp,
+		struct z_erofs_vle_workgroup, obj);
+
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+	work = z_erofs_vle_grab_work(grp, pageofs);
+	primary = true;
+#else
+	BUG();
+#endif
+
+	DBG_BUGON(work->pageofs != pageofs);
+
+	/*
+	 * lock must be taken first to avoid grp->next == NIL between
+	 * claiming workgroup and adding pages:
+	 *                        grp->next != NIL
+	 *   grp->next = NIL
+	 *   mutex_unlock_all
+	 *                        mutex_lock(&work->lock)
+	 *                        add all pages to pagevec
+	 *
+	 * [correct locking case 1]:
+	 *   mutex_lock(grp->work[a])
+	 *   ...
+	 *   mutex_lock(grp->work[b])     mutex_lock(grp->work[c])
+	 *   ...                          *role = SECONDARY
+	 *                                add all pages to pagevec
+	 *                                ...
+	 *                                mutex_unlock(grp->work[c])
+	 *   mutex_lock(grp->work[c])
+	 *   ...
+	 *   grp->next = NIL
+	 *   mutex_unlock_all
+	 *
+	 * [correct locking case 2]:
+	 *   mutex_lock(grp->work[b])
+	 *   ...
+	 *   mutex_lock(grp->work[a])
+	 *   ...
+	 *   mutex_lock(grp->work[c])
+	 *   ...
+	 *   grp->next = NIL
+	 *   mutex_unlock_all
+	 *                                mutex_lock(grp->work[a])
+	 *                                *role = PRIMARY_OWNER
+	 *                                add all pages to pagevec
+	 *                                ...
+	 */
+	mutex_lock(&work->lock);
+
+	*hosted = false;
+	if (!primary)
+		*role = Z_EROFS_VLE_WORK_SECONDARY;
+	/* claim the workgroup if possible */
+	else if (try_to_claim_workgroup(grp, owned_head, hosted))
+		*role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
+	else
+		*role = Z_EROFS_VLE_WORK_PRIMARY;
+
+	return work;
+}
+
+static struct z_erofs_vle_work *
+z_erofs_vle_work_register(struct super_block *sb,
+			  struct z_erofs_vle_workgroup **grp_ret,
+			  struct erofs_map_blocks *map,
+			  pgoff_t index, unsigned pageofs,
+			  enum z_erofs_vle_work_role *role,
+			  z_erofs_vle_owned_workgrp_t *owned_head,
+			  bool *hosted)
+{
+	bool newgrp = false;
+	struct z_erofs_vle_workgroup *grp = *grp_ret;
+	struct z_erofs_vle_work *work;
+
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+	BUG_ON(grp != NULL);
+#else
+	if (grp != NULL)
+		goto skip;
+#endif
+	/* no available workgroup, let's allocate one */
+	grp = kmem_cache_zalloc(z_erofs_workgroup_cachep, GFP_NOFS);
+	if (unlikely(grp == NULL))
+		return ERR_PTR(-ENOMEM);
+
+	grp->obj.index = index;
+	grp->llen = map->m_llen;
+
+	z_erofs_vle_set_workgrp_fmt(grp,
+		(map->m_flags & EROFS_MAP_ZIPPED) ?
+			Z_EROFS_VLE_WORKGRP_FMT_LZ4 :
+			Z_EROFS_VLE_WORKGRP_FMT_PLAIN);
+	atomic_set(&grp->obj.refcount, 1);
+
+	/* new workgrps have been claimed as type 1 */
+	WRITE_ONCE(grp->next, *owned_head);
+	/* primary and followed work for all new workgrps */
+	*role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
+	/* it should be submitted by ourselves */
+	*hosted = true;
+
+	newgrp = true;
+#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF
+skip:
+	/* currently unimplemented */
+	BUG();
+#else
+	work = z_erofs_vle_grab_primary_work(grp);
+#endif
+	work->pageofs = pageofs;
+
+	mutex_init(&work->lock);
+
+	if (newgrp) {
+		int err = erofs_register_workgroup(sb, &grp->obj, 0);
+
+		if (err) {
+			kmem_cache_free(z_erofs_workgroup_cachep, grp);
+			return ERR_PTR(-EAGAIN);
+		}
+	}
+
+	*owned_head = *grp_ret = grp;
+
+	mutex_lock(&work->lock);
+	return work;
+}
+
+static inline void __update_workgrp_llen(struct z_erofs_vle_workgroup *grp,
+					 unsigned int llen)
+{
+	while (1) {
+		unsigned int orig_llen = grp->llen;
+
+		if (orig_llen >= llen || orig_llen ==
+			cmpxchg(&grp->llen, orig_llen, llen))
+			break;
+	}
+}
+
+#define builder_is_followed(builder) \
+	((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED)
+
+static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
+				       struct super_block *sb,
+				       struct erofs_map_blocks *map,
+				       z_erofs_vle_owned_workgrp_t *owned_head)
+{
+	const unsigned clusterpages = erofs_clusterpages(EROFS_SB(sb));
+	const erofs_blk_t index = erofs_blknr(map->m_pa);
+	const unsigned pageofs = map->m_la & ~PAGE_MASK;
+	struct z_erofs_vle_workgroup *grp;
+	struct z_erofs_vle_work *work;
+
+	DBG_BUGON(builder->work != NULL);
+
+	/* must be Z_EROFS_WORK_TAIL or the next chained work */
+	DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_NIL);
+	DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
+
+	DBG_BUGON(erofs_blkoff(map->m_pa));
+
+repeat:
+	work = z_erofs_vle_work_lookup(sb, index,
+		pageofs, &grp, &builder->role, owned_head, &builder->hosted);
+	if (work != NULL) {
+		__update_workgrp_llen(grp, map->m_llen);
+		goto got_it;
+	}
+
+	work = z_erofs_vle_work_register(sb, &grp, map, index, pageofs,
+		&builder->role, owned_head, &builder->hosted);
+
+	if (unlikely(work == ERR_PTR(-EAGAIN)))
+		goto repeat;
+
+	if (unlikely(IS_ERR(work)))
+		return PTR_ERR(work);
+got_it:
+	z_erofs_pagevec_ctor_init(&builder->vector,
+		Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, work->vcnt);
+
+	if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY) {
+		/* enable possibly in-place decompression */
+		builder->compressed_pages = grp->compressed_pages;
+		builder->compressed_deficit = clusterpages;
+	} else {
+		builder->compressed_pages = NULL;
+		builder->compressed_deficit = 0;
+	}
+
+	builder->grp = grp;
+	builder->work = work;
+	return 0;
+}
+
+/*
+ * keep in mind that no referenced workgroups will be freed
+ * only after a RCU grace period, so rcu_read_lock() could
+ * prevent a workgroup from being freed.
+ */
+static void z_erofs_rcu_callback(struct rcu_head *head)
+{
+	struct z_erofs_vle_work *work =	container_of(head,
+		struct z_erofs_vle_work, rcu);
+	struct z_erofs_vle_workgroup *grp =
+		z_erofs_vle_work_workgroup(work, true);
+
+	kmem_cache_free(z_erofs_workgroup_cachep, grp);
+}
+
+void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
+{
+	struct z_erofs_vle_workgroup *const vgrp = container_of(grp,
+		struct z_erofs_vle_workgroup, obj);
+	struct z_erofs_vle_work *const work = &vgrp->work;
+
+	call_rcu(&work->rcu, z_erofs_rcu_callback);
+}
+
+static void __z_erofs_vle_work_release(struct z_erofs_vle_workgroup *grp,
+	struct z_erofs_vle_work *work __maybe_unused)
+{
+	erofs_workgroup_put(&grp->obj);
+}
+
+void z_erofs_vle_work_release(struct z_erofs_vle_work *work)
+{
+	struct z_erofs_vle_workgroup *grp =
+		z_erofs_vle_work_workgroup(work, true);
+
+	__z_erofs_vle_work_release(grp, work);
+}
+
+static inline bool
+z_erofs_vle_work_iter_end(struct z_erofs_vle_work_builder *builder)
+{
+	struct z_erofs_vle_work *work = builder->work;
+
+	if (work == NULL)
+		return false;
+
+	z_erofs_pagevec_ctor_exit(&builder->vector, false);
+	mutex_unlock(&work->lock);
+
+	/*
+	 * if all pending pages are added, don't hold work reference
+	 * any longer if the current work isn't hosted by ourselves.
+	 */
+	if (!builder->hosted)
+		__z_erofs_vle_work_release(builder->grp, work);
+
+	builder->work = NULL;
+	builder->grp = NULL;
+	return true;
+}
+
+static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
+					       gfp_t gfp)
+{
+	struct page *page = erofs_allocpage(pagepool, gfp);
+
+	if (unlikely(page == NULL))
+		return NULL;
+
+	page->mapping = Z_EROFS_MAPPING_STAGING;
+	return page;
+}
+
+struct z_erofs_vle_frontend {
+	struct inode *const inode;
+
+	struct z_erofs_vle_work_builder builder;
+	struct erofs_map_blocks_iter m_iter;
+
+	z_erofs_vle_owned_workgrp_t owned_head;
+
+	bool initial;
+};
+
+#define VLE_FRONTEND_INIT(__i) { \
+	.inode = __i, \
+	.m_iter = { \
+		{ .m_llen = 0, .m_plen = 0 }, \
+		.mpage = NULL \
+	}, \
+	.builder = VLE_WORK_BUILDER_INIT(), \
+	.owned_head = Z_EROFS_VLE_WORKGRP_TAIL, \
+	.initial = true, }
+
+static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
+				struct page *page,
+				struct list_head *page_pool)
+{
+	struct super_block *const sb = fe->inode->i_sb;
+	struct erofs_sb_info *const sbi __maybe_unused = EROFS_SB(sb);
+	struct erofs_map_blocks_iter *const m = &fe->m_iter;
+	struct erofs_map_blocks *const map = &m->map;
+	struct z_erofs_vle_work_builder *const builder = &fe->builder;
+	const loff_t offset = page_offset(page);
+
+	bool tight = builder_is_followed(builder);
+	struct z_erofs_vle_work *work = builder->work;
+
+	enum z_erofs_page_type page_type;
+	unsigned cur, end, spiltted, index;
+	int err;
+
+	/* register locked file pages as online pages in pack */
+	z_erofs_onlinepage_init(page);
+
+	spiltted = 0;
+	end = PAGE_SIZE;
+repeat:
+	cur = end - 1;
+
+	/* lucky, within the range of the current map_blocks */
+	if (offset + cur >= map->m_la &&
+		offset + cur < map->m_la + map->m_llen)
+		goto hitted;
+
+	/* go ahead the next map_blocks */
+	debugln("%s: [out-of-range] pos %llu", __func__, offset + cur);
+
+	if (!z_erofs_vle_work_iter_end(builder))
+		fe->initial = false;
+
+	map->m_la = offset + cur;
+	map->m_llen = 0;
+	err = erofs_map_blocks_iter(fe->inode, map, &m->mpage, 0);
+	if (unlikely(err))
+		goto err_out;
+
+	/* deal with hole (FIXME! broken now) */
+	if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED)))
+		goto hitted;
+
+	DBG_BUGON(map->m_plen != 1 << sbi->clusterbits);
+	BUG_ON(erofs_blkoff(map->m_pa));
+
+	err = z_erofs_vle_work_iter_begin(builder, sb, map, &fe->owned_head);
+	if (unlikely(err))
+		goto err_out;
+
+	tight &= builder_is_followed(builder);
+	work = builder->work;
+hitted:
+	cur = end - min_t(unsigned, offset + end - map->m_la, end);
+	if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED))) {
+		zero_user_segment(page, cur, end);
+		goto next_part;
+	}
+
+	/* let's derive page type */
+	page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
+		(!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
+			(tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
+				Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
+
+retry:
+	err = z_erofs_vle_work_add_page(builder, page, page_type);
+	/* should allocate an additional staging page for pagevec */
+	if (err == -EAGAIN) {
+		struct page *const newpage =
+			__stagingpage_alloc(page_pool, GFP_NOFS);
+
+		err = z_erofs_vle_work_add_page(builder,
+			newpage, Z_EROFS_PAGE_TYPE_EXCLUSIVE);
+		if (!err)
+			goto retry;
+	}
+
+	if (unlikely(err))
+		goto err_out;
+
+	index = page->index - map->m_la / PAGE_SIZE;
+
+	/* FIXME! avoid the last relundant fixup & endio */
+	z_erofs_onlinepage_fixup(page, index, true);
+	++spiltted;
+
+	/* also update nr_pages and increase queued_pages */
+	work->nr_pages = max_t(pgoff_t, work->nr_pages, index + 1);
+next_part:
+	/* can be used for verification */
+	map->m_llen = offset + cur - map->m_la;
+
+	if ((end = cur) > 0)
+		goto repeat;
+
+	/* FIXME! avoid the last relundant fixup & endio */
+	z_erofs_onlinepage_endio(page);
+
+	debugln("%s, finish page: %pK spiltted: %u map->m_llen %llu",
+		__func__, page, spiltted, map->m_llen);
+	return 0;
+
+err_out:
+	/* TODO: the missing error handing cases */
+	return err;
+}
+
+static void z_erofs_vle_unzip_kickoff(void *ptr, int bios)
+{
+	tagptr1_t t = tagptr_init(tagptr1_t, ptr);
+	struct z_erofs_vle_unzip_io *io = tagptr_unfold_ptr(t);
+	bool background = tagptr_unfold_tags(t);
+
+	if (atomic_add_return(bios, &io->pending_bios))
+		return;
+
+	if (background)
+		queue_work(z_erofs_workqueue, &io->u.work);
+	else
+		wake_up(&io->u.wait);
+}
+
+static inline void z_erofs_vle_read_endio(struct bio *bio)
+{
+	const blk_status_t err = bio->bi_status;
+	unsigned i;
+	struct bio_vec *bvec;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		DBG_BUGON(PageUptodate(page));
+		BUG_ON(page->mapping == NULL);
+
+		if (unlikely(err))
+			SetPageError(page);
+	}
+
+	z_erofs_vle_unzip_kickoff(bio->bi_private, -1);
+	bio_put(bio);
+}
+
+static struct page *z_pagemap_global[Z_EROFS_VLE_VMAP_GLOBAL_PAGES];
+static DEFINE_MUTEX(z_pagemap_global_lock);
+
+static int z_erofs_vle_unzip(struct super_block *sb,
+	struct z_erofs_vle_workgroup *grp,
+	struct list_head *page_pool)
+{
+	struct erofs_sb_info *const sbi = EROFS_SB(sb);
+	const unsigned clusterpages = erofs_clusterpages(sbi);
+
+	struct z_erofs_pagevec_ctor ctor;
+	unsigned nr_pages;
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+	unsigned sparsemem_pages = 0;
+#endif
+	struct page *pages_onstack[Z_EROFS_VLE_VMAP_ONSTACK_PAGES];
+	struct page **pages, **compressed_pages, *page;
+	unsigned i, llen;
+
+	enum z_erofs_page_type page_type;
+	bool overlapped;
+	struct z_erofs_vle_work *work;
+	void *vout;
+	int err;
+
+	might_sleep();
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+	work = z_erofs_vle_grab_primary_work(grp);
+#else
+	BUG();
+#endif
+	BUG_ON(!READ_ONCE(work->nr_pages));
+
+	mutex_lock(&work->lock);
+	nr_pages = work->nr_pages;
+
+	if (likely(nr_pages <= Z_EROFS_VLE_VMAP_ONSTACK_PAGES))
+		pages = pages_onstack;
+	else if (nr_pages <= Z_EROFS_VLE_VMAP_GLOBAL_PAGES &&
+		mutex_trylock(&z_pagemap_global_lock))
+		pages = z_pagemap_global;
+	else {
+repeat:
+		pages = kvmalloc_array(nr_pages,
+			sizeof(struct page *), GFP_KERNEL);
+
+		/* fallback to global pagemap for the lowmem scenario */
+		if (unlikely(pages == NULL)) {
+			if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES)
+				goto repeat;
+			else {
+				mutex_lock(&z_pagemap_global_lock);
+				pages = z_pagemap_global;
+			}
+		}
+	}
+
+	for (i = 0; i < nr_pages; ++i)
+		pages[i] = NULL;
+
+	z_erofs_pagevec_ctor_init(&ctor,
+		Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, 0);
+
+	for (i = 0; i < work->vcnt; ++i) {
+		unsigned pagenr;
+
+		page = z_erofs_pagevec_ctor_dequeue(&ctor, &page_type);
+
+		/* all pages in pagevec ought to be valid */
+		DBG_BUGON(page == NULL);
+		DBG_BUGON(page->mapping == NULL);
+
+		if (z_erofs_gather_if_stagingpage(page_pool, page))
+			continue;
+
+		if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
+			pagenr = 0;
+		else
+			pagenr = z_erofs_onlinepage_index(page);
+
+		BUG_ON(pagenr >= nr_pages);
+
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+		BUG_ON(pages[pagenr] != NULL);
+		++sparsemem_pages;
+#endif
+		pages[pagenr] = page;
+	}
+
+	z_erofs_pagevec_ctor_exit(&ctor, true);
+
+	overlapped = false;
+	compressed_pages = grp->compressed_pages;
+
+	for (i = 0; i < clusterpages; ++i) {
+		unsigned pagenr;
+
+		page = compressed_pages[i];
+
+		/* all compressed pages ought to be valid */
+		DBG_BUGON(page == NULL);
+		DBG_BUGON(page->mapping == NULL);
+
+		if (z_erofs_is_stagingpage(page))
+			continue;
+
+		/* only non-head page could be reused as a compressed page */
+		pagenr = z_erofs_onlinepage_index(page);
+
+		BUG_ON(pagenr >= nr_pages);
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+		BUG_ON(pages[pagenr] != NULL);
+		++sparsemem_pages;
+#endif
+		pages[pagenr] = page;
+
+		overlapped = true;
+	}
+
+	llen = (nr_pages << PAGE_SHIFT) - work->pageofs;
+
+	if (z_erofs_vle_workgrp_fmt(grp) == Z_EROFS_VLE_WORKGRP_FMT_PLAIN) {
+		/* FIXME! this should be fixed in the future */
+		BUG_ON(grp->llen != llen);
+
+		err = z_erofs_vle_plain_copy(compressed_pages, clusterpages,
+			pages, nr_pages, work->pageofs);
+		goto out;
+	}
+
+	if (llen > grp->llen)
+		llen = grp->llen;
+
+	err = z_erofs_vle_unzip_fast_percpu(compressed_pages,
+		clusterpages, pages, llen, work->pageofs,
+		z_erofs_onlinepage_endio);
+	if (err != -ENOTSUPP)
+		goto out_percpu;
+
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+	if (sparsemem_pages >= nr_pages) {
+		BUG_ON(sparsemem_pages > nr_pages);
+		goto skip_allocpage;
+	}
+#endif
+
+	for (i = 0; i < nr_pages; ++i) {
+		if (pages[i] != NULL)
+			continue;
+
+		pages[i] = __stagingpage_alloc(page_pool, GFP_NOFS);
+	}
+
+#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
+skip_allocpage:
+#endif
+	vout = erofs_vmap(pages, nr_pages);
+
+	err = z_erofs_vle_unzip_vmap(compressed_pages,
+		clusterpages, vout, llen, work->pageofs, overlapped);
+
+	erofs_vunmap(vout, nr_pages);
+
+out:
+	for (i = 0; i < nr_pages; ++i) {
+		page = pages[i];
+		DBG_BUGON(page->mapping == NULL);
+
+		/* recycle all individual staging pages */
+		if (z_erofs_gather_if_stagingpage(page_pool, page))
+			continue;
+
+		if (unlikely(err < 0))
+			SetPageError(page);
+
+		z_erofs_onlinepage_endio(page);
+	}
+
+out_percpu:
+	for (i = 0; i < clusterpages; ++i) {
+		page = compressed_pages[i];
+
+		/* recycle all individual staging pages */
+		(void)z_erofs_gather_if_stagingpage(page_pool, page);
+
+		WRITE_ONCE(compressed_pages[i], NULL);
+	}
+
+	if (pages == z_pagemap_global)
+		mutex_unlock(&z_pagemap_global_lock);
+	else if (unlikely(pages != pages_onstack))
+		kvfree(pages);
+
+	work->nr_pages = 0;
+	work->vcnt = 0;
+
+	/* all work locks MUST be taken before the following line */
+
+	WRITE_ONCE(grp->next, Z_EROFS_VLE_WORKGRP_NIL);
+
+	/* all work locks SHOULD be released right now */
+	mutex_unlock(&work->lock);
+
+	z_erofs_vle_work_release(work);
+	return err;
+}
+
+static void z_erofs_vle_unzip_all(struct super_block *sb,
+				  struct z_erofs_vle_unzip_io *io,
+				  struct list_head *page_pool)
+{
+	z_erofs_vle_owned_workgrp_t owned = io->head;
+
+	while (owned != Z_EROFS_VLE_WORKGRP_TAIL_CLOSED) {
+		struct z_erofs_vle_workgroup *grp;
+
+		/* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
+		DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_TAIL);
+
+		/* no possible that 'owned' equals NULL */
+		DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_NIL);
+
+		grp = owned;
+		owned = READ_ONCE(grp->next);
+
+		z_erofs_vle_unzip(sb, grp, page_pool);
+	};
+}
+
+static void z_erofs_vle_unzip_wq(struct work_struct *work)
+{
+	struct z_erofs_vle_unzip_io_sb *iosb = container_of(work,
+		struct z_erofs_vle_unzip_io_sb, io.u.work);
+	LIST_HEAD(page_pool);
+
+	BUG_ON(iosb->io.head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
+	z_erofs_vle_unzip_all(iosb->sb, &iosb->io, &page_pool);
+
+	put_pages_list(&page_pool);
+	kvfree(iosb);
+}
+
+static inline struct z_erofs_vle_unzip_io *
+prepare_io_handler(struct super_block *sb,
+		   struct z_erofs_vle_unzip_io *io,
+		   bool background)
+{
+	struct z_erofs_vle_unzip_io_sb *iosb;
+
+	if (!background) {
+		/* waitqueue available for foreground io */
+		BUG_ON(io == NULL);
+
+		init_waitqueue_head(&io->u.wait);
+		atomic_set(&io->pending_bios, 0);
+		goto out;
+	}
+
+	if (io != NULL)
+		BUG();
+	else {
+		/* allocate extra io descriptor for background io */
+		iosb = kvzalloc(sizeof(struct z_erofs_vle_unzip_io_sb),
+			GFP_KERNEL | __GFP_NOFAIL);
+		BUG_ON(iosb == NULL);
+
+		io = &iosb->io;
+	}
+
+	iosb->sb = sb;
+	INIT_WORK(&io->u.work, z_erofs_vle_unzip_wq);
+out:
+	io->head = Z_EROFS_VLE_WORKGRP_TAIL_CLOSED;
+	return io;
+}
+
+#define __FSIO_1 0
+
+static bool z_erofs_vle_submit_all(struct super_block *sb,
+				   z_erofs_vle_owned_workgrp_t owned_head,
+				   struct list_head *pagepool,
+				   struct z_erofs_vle_unzip_io *fg_io,
+				   bool force_fg)
+{
+	struct erofs_sb_info *const sbi = EROFS_SB(sb);
+	const unsigned clusterpages = erofs_clusterpages(sbi);
+	const gfp_t gfp = GFP_NOFS;
+	struct z_erofs_vle_unzip_io *ios[1 + __FSIO_1];
+	struct bio *bio;
+	tagptr1_t bi_private;
+	/* since bio will be NULL, no need to initialize last_index */
+	pgoff_t uninitialized_var(last_index);
+	bool force_submit = false;
+	unsigned nr_bios;
+
+	if (unlikely(owned_head == Z_EROFS_VLE_WORKGRP_TAIL))
+		return false;
+
+	/*
+	 * force_fg == 1, (io, fg_io[0]) no io, (io, fg_io[1]) need submit io
+	 * force_fg == 0, (io, fg_io[0]) no io; (io[1], bg_io) need submit io
+	 */
+	if (force_fg) {
+		ios[__FSIO_1] = prepare_io_handler(sb, fg_io + __FSIO_1, false);
+		bi_private = tagptr_fold(tagptr1_t, ios[__FSIO_1], 0);
+	} else {
+		ios[__FSIO_1] = prepare_io_handler(sb, NULL, true);
+		bi_private = tagptr_fold(tagptr1_t, ios[__FSIO_1], 1);
+	}
+
+	nr_bios = 0;
+	force_submit = false;
+	bio = NULL;
+
+	/* by default, all need io submission */
+	ios[__FSIO_1]->head = owned_head;
+
+	do {
+		struct z_erofs_vle_workgroup *grp;
+		struct page **compressed_pages, *oldpage, *page;
+		pgoff_t first_index;
+		unsigned i = 0;
+		int err;
+
+		/* no possible 'owned_head' equals the following */
+		DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
+		DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_NIL);
+
+		grp = owned_head;
+
+		/* close the main owned chain at first */
+		owned_head = cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL,
+			Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
+
+		first_index = grp->obj.index;
+		compressed_pages = grp->compressed_pages;
+
+		force_submit |= (first_index != last_index + 1);
+repeat:
+		/* fulfill all compressed pages */
+		oldpage = page = READ_ONCE(compressed_pages[i]);
+
+		if (page != NULL)
+			BUG_ON(PageUptodate(page));
+		else {
+			page = __stagingpage_alloc(pagepool, gfp);
+
+			if (oldpage != cmpxchg(compressed_pages + i,
+				oldpage, page)) {
+				list_add(&page->lru, pagepool);
+				goto repeat;
+			}
+		}
+
+		if (bio != NULL && force_submit) {
+submit_bio_retry:
+			__submit_bio(bio, REQ_OP_READ, 0);
+			bio = NULL;
+		}
+
+		if (bio == NULL) {
+			bio = prepare_bio(sb, first_index + i,
+				BIO_MAX_PAGES, z_erofs_vle_read_endio);
+			bio->bi_private = tagptr_cast_ptr(bi_private);
+
+			++nr_bios;
+		}
+
+		err = bio_add_page(bio, page, PAGE_SIZE, 0);
+		if (err < PAGE_SIZE)
+			goto submit_bio_retry;
+
+		force_submit = false;
+		last_index = first_index + i;
+		if (++i < clusterpages)
+			goto repeat;
+	} while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL);
+
+	if (bio != NULL)
+		__submit_bio(bio, REQ_OP_READ, 0);
+
+	BUG_ON(!nr_bios);
+
+	z_erofs_vle_unzip_kickoff(tagptr_cast_ptr(bi_private), nr_bios);
+	return true;
+}
+
+static void z_erofs_submit_and_unzip(struct z_erofs_vle_frontend *f,
+				     struct list_head *pagepool,
+				     bool force_fg)
+{
+	struct super_block *sb = f->inode->i_sb;
+	struct z_erofs_vle_unzip_io io[1 + __FSIO_1];
+
+	if (!z_erofs_vle_submit_all(sb, f->owned_head, pagepool, io, force_fg))
+		return;
+
+	if (!force_fg)
+		return;
+
+	/* wait until all bios are completed */
+	wait_event(io[__FSIO_1].u.wait,
+		!atomic_read(&io[__FSIO_1].pending_bios));
+
+	/* let's synchronous decompression */
+	z_erofs_vle_unzip_all(sb, &io[__FSIO_1], pagepool);
+}
+
+static int z_erofs_vle_normalaccess_readpage(struct file *file,
+					     struct page *page)
+{
+	struct inode *const inode = page->mapping->host;
+	struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode);
+	int err;
+	LIST_HEAD(pagepool);
+
+	err = z_erofs_do_read_page(&f, page, &pagepool);
+	(void)z_erofs_vle_work_iter_end(&f.builder);
+
+	if (err) {
+		errln("%s, failed to read, err [%d]", __func__, err);
+		goto out;
+	}
+
+	z_erofs_submit_and_unzip(&f, &pagepool, true);
+out:
+	if (f.m_iter.mpage != NULL)
+		put_page(f.m_iter.mpage);
+
+	/* clean up the remaining free pages */
+	put_pages_list(&pagepool);
+	return 0;
+}
+
+static inline int __z_erofs_vle_normalaccess_readpages(
+	struct file *filp,
+	struct address_space *mapping,
+	struct list_head *pages, unsigned nr_pages, bool sync)
+{
+	struct inode *const inode = mapping->host;
+
+	struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode);
+	gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
+	struct page *head = NULL;
+	LIST_HEAD(pagepool);
+
+	for (; nr_pages; --nr_pages) {
+		struct page *page = lru_to_page(pages);
+
+		prefetchw(&page->flags);
+		list_del(&page->lru);
+
+		if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
+			list_add(&page->lru, &pagepool);
+			continue;
+		}
+
+		BUG_ON(PagePrivate(page));
+		set_page_private(page, (unsigned long)head);
+		head = page;
+	}
+
+	while (head != NULL) {
+		struct page *page = head;
+		int err;
+
+		/* traversal in reverse order */
+		head = (void *)page_private(page);
+
+		err = z_erofs_do_read_page(&f, page, &pagepool);
+		if (err) {
+			struct erofs_vnode *vi = EROFS_V(inode);
+
+			errln("%s, readahead error at page %lu of nid %llu",
+				__func__, page->index, vi->nid);
+		}
+
+		put_page(page);
+	}
+
+	(void)z_erofs_vle_work_iter_end(&f.builder);
+
+	z_erofs_submit_and_unzip(&f, &pagepool, sync);
+
+	if (f.m_iter.mpage != NULL)
+		put_page(f.m_iter.mpage);
+
+	/* clean up the remaining free pages */
+	put_pages_list(&pagepool);
+	return 0;
+}
+
+static int z_erofs_vle_normalaccess_readpages(
+	struct file *filp,
+	struct address_space *mapping,
+	struct list_head *pages, unsigned nr_pages)
+{
+	return __z_erofs_vle_normalaccess_readpages(filp,
+		mapping, pages, nr_pages,
+		nr_pages < 4 /* sync */);
+}
+
+const struct address_space_operations z_erofs_vle_normalaccess_aops = {
+	.readpage = z_erofs_vle_normalaccess_readpage,
+	.readpages = z_erofs_vle_normalaccess_readpages,
+};
 
 #define __vle_cluster_advise(x, bit, bits) \
 	((le16_to_cpu(x) >> (bit)) & ((1 << (bits)) - 1))
diff --git a/drivers/staging/erofs/unzip_vle.h b/drivers/staging/erofs/unzip_vle.h
index b34f5bc..3521dfb 100644
--- a/drivers/staging/erofs/unzip_vle.h
+++ b/drivers/staging/erofs/unzip_vle.h
@@ -14,9 +14,213 @@
 #define __EROFS_FS_UNZIP_VLE_H
 
 #include "internal.h"
+#include "unzip_pagevec.h"
+
+/*
+ *  - 0x5A110C8D ('sallocated', Z_EROFS_MAPPING_STAGING) -
+ * used for temporary allocated pages (via erofs_allocpage),
+ * in order to seperate those from NULL mapping (eg. truncated pages)
+ */
+#define Z_EROFS_MAPPING_STAGING		((void *)0x5A110C8D)
+
+#define z_erofs_is_stagingpage(page)	\
+	((page)->mapping == Z_EROFS_MAPPING_STAGING)
+
+static inline bool z_erofs_gather_if_stagingpage(struct list_head *page_pool,
+						 struct page *page)
+{
+	if (z_erofs_is_stagingpage(page)) {
+		list_add(&page->lru, page_pool);
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Structure fields follow one of the following exclusion rules.
+ *
+ * I: Modifiable by initialization/destruction paths and read-only
+ *    for everyone else.
+ *
+ */
 
 #define Z_EROFS_VLE_INLINE_PAGEVECS     3
 
+struct z_erofs_vle_work {
+	/* struct z_erofs_vle_work *left, *right; */
+
+#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF
+	struct list_head list;
+
+	atomic_t refcount;
+#endif
+	struct mutex lock;
+
+	/* I: decompression offset in page */
+	unsigned short pageofs;
+	unsigned short nr_pages;
+
+	/* L: queued pages in pagevec[] */
+	unsigned vcnt;
+
+	union {
+		/* L: pagevec */
+		erofs_vtptr_t pagevec[Z_EROFS_VLE_INLINE_PAGEVECS];
+		struct rcu_head rcu;
+	};
+};
+
+#define Z_EROFS_VLE_WORKGRP_FMT_PLAIN        0
+#define Z_EROFS_VLE_WORKGRP_FMT_LZ4          1
+#define Z_EROFS_VLE_WORKGRP_FMT_MASK         1
+
+typedef struct z_erofs_vle_workgroup *z_erofs_vle_owned_workgrp_t;
+
+struct z_erofs_vle_workgroup {
+	struct erofs_workgroup obj;
+	struct z_erofs_vle_work work;
+
+	/* next owned workgroup */
+	z_erofs_vle_owned_workgrp_t next;
+
+	/* compressed pages (including multi-usage pages) */
+	struct page *compressed_pages[Z_EROFS_CLUSTER_MAX_PAGES];
+	unsigned int llen, flags;
+};
+
+/* let's avoid the valid 32-bit kernel addresses */
+
+/* the chained workgroup has't submitted io (still open) */
+#define Z_EROFS_VLE_WORKGRP_TAIL        ((void *)0x5F0ECAFE)
+/* the chained workgroup has already submitted io */
+#define Z_EROFS_VLE_WORKGRP_TAIL_CLOSED ((void *)0x5F0EDEAD)
+
+#define Z_EROFS_VLE_WORKGRP_NIL         (NULL)
+
+#define z_erofs_vle_workgrp_fmt(grp)	\
+	((grp)->flags & Z_EROFS_VLE_WORKGRP_FMT_MASK)
+
+static inline void z_erofs_vle_set_workgrp_fmt(
+	struct z_erofs_vle_workgroup *grp,
+	unsigned int fmt)
+{
+	grp->flags = fmt | (grp->flags & ~Z_EROFS_VLE_WORKGRP_FMT_MASK);
+}
+
+#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF
+#error multiref decompression is unimplemented yet
+#else
+
+#define z_erofs_vle_grab_primary_work(grp)	(&(grp)->work)
+#define z_erofs_vle_grab_work(grp, pageofs)	(&(grp)->work)
+#define z_erofs_vle_work_workgroup(wrk, primary)	\
+	((primary) ? container_of(wrk,	\
+		struct z_erofs_vle_workgroup, work) : \
+		({ BUG(); (void *)NULL; }))
+
+#endif
+
+#define Z_EROFS_WORKGROUP_SIZE       sizeof(struct z_erofs_vle_workgroup)
+
+struct z_erofs_vle_unzip_io {
+	atomic_t pending_bios;
+	z_erofs_vle_owned_workgrp_t head;
+
+	union {
+		wait_queue_head_t wait;
+		struct work_struct work;
+	} u;
+};
+
+struct z_erofs_vle_unzip_io_sb {
+	struct z_erofs_vle_unzip_io io;
+	struct super_block *sb;
+};
+
+#define Z_EROFS_ONLINEPAGE_COUNT_BITS 2
+#define Z_EROFS_ONLINEPAGE_COUNT_MASK ((1 << Z_EROFS_ONLINEPAGE_COUNT_BITS) - 1)
+#define Z_EROFS_ONLINEPAGE_INDEX_SHIFT  (Z_EROFS_ONLINEPAGE_COUNT_BITS)
+
+/*
+ * waiters (aka. ongoing_packs): # to unlock the page
+ * sub-index: 0 - for partial page, >= 1 full page sub-index
+ */
+typedef atomic_t z_erofs_onlinepage_t;
+
+/* type punning */
+union z_erofs_onlinepage_converter {
+	z_erofs_onlinepage_t *o;
+	unsigned long *v;
+};
+
+static inline unsigned z_erofs_onlinepage_index(struct page *page)
+{
+	union z_erofs_onlinepage_converter u;
+
+	BUG_ON(!PagePrivate(page));
+	u.v = &page_private(page);
+
+	return atomic_read(u.o) >> Z_EROFS_ONLINEPAGE_INDEX_SHIFT;
+}
+
+static inline void z_erofs_onlinepage_init(struct page *page)
+{
+	union {
+		z_erofs_onlinepage_t o;
+		unsigned long v;
+	/* keep from being unlocked in advance */
+	} u = { .o = ATOMIC_INIT(1) };
+
+	set_page_private(page, u.v);
+	smp_wmb();
+	SetPagePrivate(page);
+}
+
+static inline void z_erofs_onlinepage_fixup(struct page *page,
+	uintptr_t index, bool down)
+{
+	unsigned long *p, o, v, id;
+repeat:
+	p = &page_private(page);
+	o = READ_ONCE(*p);
+
+	id = o >> Z_EROFS_ONLINEPAGE_INDEX_SHIFT;
+	if (id) {
+		if (!index)
+			return;
+
+		BUG_ON(id != index);
+	}
+
+	v = (index << Z_EROFS_ONLINEPAGE_INDEX_SHIFT) |
+		((o & Z_EROFS_ONLINEPAGE_COUNT_MASK) + (unsigned)down);
+	if (cmpxchg(p, o, v) != o)
+		goto repeat;
+}
+
+static inline void z_erofs_onlinepage_endio(struct page *page)
+{
+	union z_erofs_onlinepage_converter u;
+	unsigned v;
+
+	BUG_ON(!PagePrivate(page));
+	u.v = &page_private(page);
+
+	v = atomic_dec_return(u.o);
+	if (!(v & Z_EROFS_ONLINEPAGE_COUNT_MASK)) {
+		ClearPagePrivate(page);
+		if (!PageError(page))
+			SetPageUptodate(page);
+		unlock_page(page);
+	}
+
+	debugln("%s, page %p value %x", __func__, page, atomic_read(u.o));
+}
+
+#define Z_EROFS_VLE_VMAP_ONSTACK_PAGES	\
+	min(THREAD_SIZE / 8 / sizeof(struct page *), 96UL)
+#define Z_EROFS_VLE_VMAP_GLOBAL_PAGES	2048
+
 /* unzip_vle_lz4.c */
 extern int z_erofs_vle_plain_copy(struct page **compressed_pages,
 	unsigned clusterpages, struct page **pages,
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index 0d4eae2..6530035 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -12,6 +12,7 @@
  */
 
 #include "internal.h"
+#include <linux/pagevec.h>
 
 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
 {
@@ -98,11 +99,69 @@ int erofs_register_workgroup(struct super_block *sb,
 	return err;
 }
 
+extern void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
+
+int erofs_workgroup_put(struct erofs_workgroup *grp)
+{
+	int count = atomic_dec_return(&grp->refcount);
+
+	if (count == 1)
+		atomic_long_inc(&erofs_global_shrink_cnt);
+	else if (!count) {
+		atomic_long_dec(&erofs_global_shrink_cnt);
+		erofs_workgroup_free_rcu(grp);
+	}
+	return count;
+}
+
 unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
 				       unsigned long nr_shrink,
 				       bool cleanup)
 {
-	return 0;
+	pgoff_t first_index = 0;
+	void *batch[PAGEVEC_SIZE];
+	unsigned freed = 0;
+
+	int i, found;
+repeat:
+	erofs_workstn_lock(sbi);
+
+	found = radix_tree_gang_lookup(&sbi->workstn_tree,
+		batch, first_index, PAGEVEC_SIZE);
+
+	for (i = 0; i < found; ++i) {
+		int cnt;
+		struct erofs_workgroup *grp = (void *)
+			((unsigned long)batch[i] &
+				~RADIX_TREE_EXCEPTIONAL_ENTRY);
+
+		first_index = grp->index + 1;
+
+		cnt = atomic_read(&grp->refcount);
+		BUG_ON(cnt <= 0);
+
+		if (cleanup)
+			BUG_ON(cnt != 1);
+
+		else if (cnt > 1)
+			continue;
+
+		if (radix_tree_delete(&sbi->workstn_tree,
+			grp->index) != grp)
+			continue;
+
+		/* (rarely) grabbed again when freeing */
+		erofs_workgroup_put(grp);
+
+		++freed;
+		if (unlikely(!--nr_shrink))
+			break;
+	}
+	erofs_workstn_unlock(sbi);
+
+	if (i && nr_shrink)
+		goto repeat;
+	return freed;
 }
 
 #endif
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 24/25] staging: erofs: introduce cached decompression
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (22 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 23/25] staging: erofs: introduce VLE decompression support Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-26 12:22   ` [PATCH 25/25] staging: erofs: add a TODO and update MAINTAINERS for staging Gao Xiang
                     ` (2 subsequent siblings)
  26 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch adds an optional choice which can be
enabled by users in order to cache both incomplete
ends of compressed clusters as a complement to
the in-place decompression in order to boost random
read, but it costs more memory than the in-place
decompression only.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/Kconfig     |  38 ++++++
 drivers/staging/erofs/internal.h  |  26 ++++
 drivers/staging/erofs/super.c     |  73 ++++++++++
 drivers/staging/erofs/unzip_vle.c | 274 ++++++++++++++++++++++++++++++++++++++
 drivers/staging/erofs/utils.c     |  17 ++-
 5 files changed, 427 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index b55ce1c..663b755 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -101,3 +101,41 @@ config EROFS_FS_CLUSTER_PAGE_LIMIT
 	  than 2. Otherwise, the image cannot be mounted
 	  correctly on this kernel.
 
+choice
+	prompt "EROFS VLE Data Decompression mode"
+	depends on EROFS_FS_ZIP
+	default EROFS_FS_ZIP_CACHE_BIPOLAR
+	help
+	  EROFS supports three options for VLE decompression.
+	  "In-place Decompression Only" consumes the minimum memory
+	  with lowest random read.
+
+	  "Bipolar Cached Decompression" consumes the maximum memory
+	  with highest random read.
+
+	  If unsure, select "Bipolar Cached Decompression"
+
+config EROFS_FS_ZIP_NO_CACHE
+	bool "In-place Decompression Only"
+	help
+	  Read compressed data into page cache and do in-place
+	  decompression directly.
+
+config EROFS_FS_ZIP_CACHE_UNIPOLAR
+	bool "Unipolar Cached Decompression"
+	help
+	  For each request, it caches the last compressed page
+	  for further reading.
+	  It still decompresses in place for the rest compressed pages.
+
+config EROFS_FS_ZIP_CACHE_BIPOLAR
+	bool "Bipolar Cached Decompression"
+	help
+	  For each request, it caches the both end compressed pages
+	  for further reading.
+	  It still decompresses in place for the rest compressed pages.
+
+	  Recommended for performance priority.
+
+endchoice
+
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 3adec7d..669f93a 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -58,6 +58,18 @@ struct erofs_fault_info {
 };
 #endif
 
+#ifdef CONFIG_EROFS_FS_ZIP_CACHE_BIPOLAR
+#define EROFS_FS_ZIP_CACHE_LVL	(2)
+#elif defined(EROFS_FS_ZIP_CACHE_UNIPOLAR)
+#define EROFS_FS_ZIP_CACHE_LVL	(1)
+#else
+#define EROFS_FS_ZIP_CACHE_LVL	(0)
+#endif
+
+#if (!defined(EROFS_FS_HAS_MANAGED_CACHE) && (EROFS_FS_ZIP_CACHE_LVL > 0))
+#define EROFS_FS_HAS_MANAGED_CACHE
+#endif
+
 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
 #define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
 
@@ -82,6 +94,11 @@ struct erofs_sb_info {
 
 	/* the dedicated workstation for compression */
 	struct radix_tree_root workstn_tree;
+
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	struct inode *managed_cache;
+#endif
+
 #endif
 
 	u32 build_time_nsec;
@@ -240,6 +257,15 @@ static inline void erofs_workstation_cleanup_all(struct super_block *sb)
 	erofs_shrink_workstation(EROFS_SB(sb), ~0UL, true);
 }
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+#define EROFS_UNALLOCATED_CACHED_PAGE	((void *)0x5F0EF00D)
+
+extern int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+	struct erofs_workgroup *egrp);
+extern int try_to_free_cached_page(struct address_space *mapping,
+	struct page *page);
+#endif
+
 #endif
 
 /* we strictly follow PAGE_SIZE and no buffer head yet */
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 2bd433a..97da5c8 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -256,6 +256,63 @@ static int parse_options(struct super_block *sb, char *options)
 	return 0;
 }
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+
+static const struct address_space_operations managed_cache_aops;
+
+static int managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
+{
+	int ret = 1;	/* 0 - busy */
+	struct address_space *const mapping = page->mapping;
+
+	BUG_ON(!PageLocked(page));
+	BUG_ON(mapping->a_ops != &managed_cache_aops);
+
+	if (PagePrivate(page))
+		ret = try_to_free_cached_page(mapping, page);
+
+	return ret;
+}
+
+static void managed_cache_invalidatepage(struct page *page,
+	unsigned int offset, unsigned int length)
+{
+	const unsigned int stop = length + offset;
+
+	BUG_ON(!PageLocked(page));
+
+	/* Check for overflow */
+	BUG_ON(stop > PAGE_SIZE || stop < length);
+
+	if (offset == 0 && stop == PAGE_SIZE)
+		while (!managed_cache_releasepage(page, GFP_NOFS))
+			cond_resched();
+}
+
+static const struct address_space_operations managed_cache_aops = {
+	.releasepage = managed_cache_releasepage,
+	.invalidatepage = managed_cache_invalidatepage,
+};
+
+static struct inode *erofs_init_managed_cache(struct super_block *sb)
+{
+	struct inode *inode = new_inode(sb);
+
+	if (unlikely(inode == NULL))
+		return ERR_PTR(-ENOMEM);
+
+	set_nlink(inode, 1);
+	inode->i_size = OFFSET_MAX;
+
+	inode->i_mapping->a_ops = &managed_cache_aops;
+	mapping_set_gfp_mask(inode->i_mapping,
+			     GFP_NOFS | __GFP_HIGHMEM |
+			     __GFP_MOVABLE |  __GFP_NOFAIL);
+	return inode;
+}
+
+#endif
+
 static int erofs_read_super(struct super_block *sb,
 	const char *dev_name, void *data, int silent)
 {
@@ -307,6 +364,14 @@ static int erofs_read_super(struct super_block *sb,
 	INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
 #endif
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	sbi->managed_cache = erofs_init_managed_cache(sb);
+	if (IS_ERR(sbi->managed_cache)) {
+		err = PTR_ERR(sbi->managed_cache);
+		goto err_init_managed_cache;
+	}
+#endif
+
 	/* get the root inode */
 	inode = erofs_iget(sb, ROOT_NID(sbi), true);
 	if (IS_ERR(inode)) {
@@ -361,6 +426,10 @@ static int erofs_read_super(struct super_block *sb,
 	if (sb->s_root == NULL)
 		iput(inode);
 err_iget:
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	iput(sbi->managed_cache);
+err_init_managed_cache:
+#endif
 err_parseopt:
 err_sbread:
 	sb->s_fs_info = NULL;
@@ -386,6 +455,10 @@ static void erofs_put_super(struct super_block *sb)
 	infoln("unmounted for %s", sbi->dev_name);
 	__putname(sbi->dev_name);
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	iput(sbi->managed_cache);
+#endif
+
 	mutex_lock(&sbi->umount_mutex);
 
 #ifdef CONFIG_EROFS_FS_ZIP
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index f0ead60..7671fe8 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -95,6 +95,111 @@ struct z_erofs_vle_work_builder {
 #define VLE_WORK_BUILDER_INIT()	\
 	{ .work = NULL, .role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED }
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+
+static bool grab_managed_cache_pages(struct address_space *mapping,
+				     erofs_blk_t start,
+				     struct page **compressed_pages,
+				     int clusterblks,
+				     bool reserve_allocation)
+{
+	bool noio = true;
+	unsigned int i;
+
+	/* TODO: optimize by introducing find_get_pages_range */
+	for (i = 0; i < clusterblks; ++i) {
+		struct page *page, *found;
+
+		if (READ_ONCE(compressed_pages[i]) != NULL)
+			continue;
+
+		page = found = find_get_page(mapping, start + i);
+		if (found == NULL) {
+			noio = false;
+			if (!reserve_allocation)
+				continue;
+			page = EROFS_UNALLOCATED_CACHED_PAGE;
+		}
+
+		if (NULL == cmpxchg(compressed_pages + i, NULL, page))
+			continue;
+
+		if (found != NULL)
+			put_page(found);
+	}
+	return noio;
+}
+
+/* called by erofs_shrinker to get rid of all compressed_pages */
+int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+				 struct erofs_workgroup *egrp)
+{
+	struct z_erofs_vle_workgroup *const grp =
+		container_of(egrp, struct z_erofs_vle_workgroup, obj);
+	struct address_space *const mapping = sbi->managed_cache->i_mapping;
+	const int clusterpages = erofs_clusterpages(sbi);
+	int i;
+
+	/*
+	 * refcount of workgroup is now freezed as 1,
+	 * therefore no need to worry about available decompression users.
+	 */
+	for (i = 0; i < clusterpages; ++i) {
+		struct page *page = grp->compressed_pages[i];
+
+		if (page == NULL || page->mapping != mapping)
+			continue;
+
+		/* block other users from reclaiming or migrating the page */
+		if (!trylock_page(page))
+			return -EBUSY;
+
+		/* barrier is implied in the following 'unlock_page' */
+		WRITE_ONCE(grp->compressed_pages[i], NULL);
+
+		set_page_private(page, 0);
+		ClearPagePrivate(page);
+
+		unlock_page(page);
+		put_page(page);
+	}
+	return 0;
+}
+
+int try_to_free_cached_page(struct address_space *mapping, struct page *page)
+{
+	struct erofs_sb_info *const sbi = EROFS_SB(mapping->host->i_sb);
+	const unsigned int clusterpages = erofs_clusterpages(sbi);
+
+	struct z_erofs_vle_workgroup *grp;
+	int ret = 0;	/* 0 - busy */
+
+	/* prevent the workgroup from being freed */
+	rcu_read_lock();
+	grp = (void *)page_private(page);
+
+	if (erofs_workgroup_try_to_freeze(&grp->obj, 1)) {
+		unsigned int i;
+
+		for (i = 0; i < clusterpages; ++i) {
+			if (grp->compressed_pages[i] == page) {
+				WRITE_ONCE(grp->compressed_pages[i], NULL);
+				ret = 1;
+				break;
+			}
+		}
+		erofs_workgroup_unfreeze(&grp->obj, 1);
+	}
+	rcu_read_unlock();
+
+	if (ret) {
+		ClearPagePrivate(page);
+		put_page(page);
+	}
+	return ret;
+}
+#endif
+
 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
 static inline bool try_to_reuse_as_compressed_page(
 	struct z_erofs_vle_work_builder *b,
@@ -463,6 +568,9 @@ struct z_erofs_vle_frontend {
 	z_erofs_vle_owned_workgrp_t owned_head;
 
 	bool initial;
+#if (EROFS_FS_ZIP_CACHE_LVL >= 2)
+	erofs_off_t cachedzone_la;
+#endif
 };
 
 #define VLE_FRONTEND_INIT(__i) { \
@@ -489,6 +597,12 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 	bool tight = builder_is_followed(builder);
 	struct z_erofs_vle_work *work = builder->work;
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	struct address_space *const mngda = sbi->managed_cache->i_mapping;
+	struct z_erofs_vle_workgroup *grp;
+	bool noio_outoforder;
+#endif
+
 	enum z_erofs_page_type page_type;
 	unsigned cur, end, spiltted, index;
 	int err;
@@ -529,6 +643,21 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 	if (unlikely(err))
 		goto err_out;
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	grp = fe->builder.grp;
+
+	/* let's do out-of-order decompression for noio */
+	noio_outoforder = grab_managed_cache_pages(mngda,
+		erofs_blknr(map->m_pa),
+		grp->compressed_pages, erofs_blknr(map->m_plen),
+		/* compressed page caching selection strategy */
+		fe->initial | (EROFS_FS_ZIP_CACHE_LVL >= 2 ?
+			map->m_la < fe->cachedzone_la : 0));
+
+	if (noio_outoforder && builder_is_followed(builder))
+		builder->role = Z_EROFS_VLE_WORK_PRIMARY;
+#endif
+
 	tight &= builder_is_followed(builder);
 	work = builder->work;
 hitted:
@@ -607,15 +736,39 @@ static inline void z_erofs_vle_read_endio(struct bio *bio)
 	const blk_status_t err = bio->bi_status;
 	unsigned i;
 	struct bio_vec *bvec;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	struct address_space *mngda = NULL;
+#endif
 
 	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
+		bool cachemngd = false;
 
 		DBG_BUGON(PageUptodate(page));
 		BUG_ON(page->mapping == NULL);
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		if (unlikely(mngda == NULL && !z_erofs_is_stagingpage(page))) {
+			struct inode *const inode = page->mapping->host;
+			struct super_block *const sb = inode->i_sb;
+
+			mngda = EROFS_SB(sb)->managed_cache->i_mapping;
+		}
+
+		/*
+		 * If mngda has not gotten, it equals NULL,
+		 * however, page->mapping never be NULL if working properly.
+		 */
+		cachemngd = (page->mapping == mngda);
+#endif
+
 		if (unlikely(err))
 			SetPageError(page);
+		else if (cachemngd)
+			SetPageUptodate(page);
+
+		if (cachemngd)
+			unlock_page(page);
 	}
 
 	z_erofs_vle_unzip_kickoff(bio->bi_private, -1);
@@ -630,6 +783,9 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 	struct list_head *page_pool)
 {
 	struct erofs_sb_info *const sbi = EROFS_SB(sb);
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	struct address_space *const mngda = sbi->managed_cache->i_mapping;
+#endif
 	const unsigned clusterpages = erofs_clusterpages(sbi);
 
 	struct z_erofs_pagevec_ctor ctor;
@@ -727,6 +883,13 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 
 		if (z_erofs_is_stagingpage(page))
 			continue;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		else if (page->mapping == mngda) {
+			BUG_ON(PageLocked(page));
+			BUG_ON(!PageUptodate(page));
+			continue;
+		}
+#endif
 
 		/* only non-head page could be reused as a compressed page */
 		pagenr = z_erofs_onlinepage_index(page);
@@ -804,6 +967,10 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 	for (i = 0; i < clusterpages; ++i) {
 		page = compressed_pages[i];
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		if (page->mapping == mngda)
+			continue;
+#endif
 		/* recycle all individual staging pages */
 		(void)z_erofs_gather_if_stagingpage(page_pool, page);
 
@@ -898,7 +1065,31 @@ static void z_erofs_vle_unzip_wq(struct work_struct *work)
 	return io;
 }
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+/* true - unlocked (noio), false - locked (need submit io) */
+static inline bool recover_managed_page(struct z_erofs_vle_workgroup *grp,
+					struct page *page)
+{
+	wait_on_page_locked(page);
+	if (PagePrivate(page) && PageUptodate(page))
+		return true;
+
+	lock_page(page);
+	if (unlikely(!PagePrivate(page))) {
+		set_page_private(page, (unsigned long)grp);
+		SetPagePrivate(page);
+	}
+	if (unlikely(PageUptodate(page))) {
+		unlock_page(page);
+		return true;
+	}
+	return false;
+}
+
+#define __FSIO_1 1
+#else
 #define __FSIO_1 0
+#endif
 
 static bool z_erofs_vle_submit_all(struct super_block *sb,
 				   z_erofs_vle_owned_workgrp_t owned_head,
@@ -909,6 +1100,10 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 	struct erofs_sb_info *const sbi = EROFS_SB(sb);
 	const unsigned clusterpages = erofs_clusterpages(sbi);
 	const gfp_t gfp = GFP_NOFS;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	struct address_space *const mngda = sbi->managed_cache->i_mapping;
+	struct z_erofs_vle_workgroup *lstgrp_noio = NULL, *lstgrp_io = NULL;
+#endif
 	struct z_erofs_vle_unzip_io *ios[1 + __FSIO_1];
 	struct bio *bio;
 	tagptr1_t bi_private;
@@ -924,6 +1119,10 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 	 * force_fg == 1, (io, fg_io[0]) no io, (io, fg_io[1]) need submit io
 	 * force_fg == 0, (io, fg_io[0]) no io; (io[1], bg_io) need submit io
 	 */
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	ios[0] = prepare_io_handler(sb, fg_io + 0, false);
+#endif
+
 	if (force_fg) {
 		ios[__FSIO_1] = prepare_io_handler(sb, fg_io + __FSIO_1, false);
 		bi_private = tagptr_fold(tagptr1_t, ios[__FSIO_1], 0);
@@ -944,6 +1143,10 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 		struct page **compressed_pages, *oldpage, *page;
 		pgoff_t first_index;
 		unsigned i = 0;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		unsigned int noio = 0;
+		bool cachemngd;
+#endif
 		int err;
 
 		/* no possible 'owned_head' equals the following */
@@ -964,15 +1167,40 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 		/* fulfill all compressed pages */
 		oldpage = page = READ_ONCE(compressed_pages[i]);
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		cachemngd = false;
+
+		if (page == EROFS_UNALLOCATED_CACHED_PAGE) {
+			cachemngd = true;
+			goto do_allocpage;
+		} else if (page != NULL) {
+			if (page->mapping != mngda)
+				BUG_ON(PageUptodate(page));
+			else if (recover_managed_page(grp, page)) {
+				/* page is uptodate, skip io submission */
+				force_submit = true;
+				++noio;
+				goto skippage;
+			}
+		} else {
+do_allocpage:
+#else
 		if (page != NULL)
 			BUG_ON(PageUptodate(page));
 		else {
+#endif
 			page = __stagingpage_alloc(pagepool, gfp);
 
 			if (oldpage != cmpxchg(compressed_pages + i,
 				oldpage, page)) {
 				list_add(&page->lru, pagepool);
 				goto repeat;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+			} else if (cachemngd && !add_to_page_cache_lru(page,
+				mngda, first_index + i, gfp)) {
+				set_page_private(page, (unsigned long)grp);
+				SetPagePrivate(page);
+#endif
 			}
 		}
 
@@ -996,14 +1224,51 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 
 		force_submit = false;
 		last_index = first_index + i;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+skippage:
+#endif
 		if (++i < clusterpages)
 			goto repeat;
+
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		if (noio < clusterpages) {
+			lstgrp_io = grp;
+		} else {
+			z_erofs_vle_owned_workgrp_t iogrp_next =
+				owned_head == Z_EROFS_VLE_WORKGRP_TAIL ?
+				Z_EROFS_VLE_WORKGRP_TAIL_CLOSED :
+				owned_head;
+
+			if (lstgrp_io == NULL)
+				ios[1]->head = iogrp_next;
+			else
+				WRITE_ONCE(lstgrp_io->next, iogrp_next);
+
+			if (lstgrp_noio == NULL)
+				ios[0]->head = grp;
+			else
+				WRITE_ONCE(lstgrp_noio->next, grp);
+
+			lstgrp_noio = grp;
+		}
+#endif
 	} while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL);
 
 	if (bio != NULL)
 		__submit_bio(bio, REQ_OP_READ, 0);
 
+#ifndef EROFS_FS_HAS_MANAGED_CACHE
 	BUG_ON(!nr_bios);
+#else
+	if (lstgrp_noio != NULL)
+		WRITE_ONCE(lstgrp_noio->next, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
+
+	if (!force_fg && !nr_bios) {
+		kvfree(container_of(ios[1],
+			struct z_erofs_vle_unzip_io_sb, io));
+		return true;
+	}
+#endif
 
 	z_erofs_vle_unzip_kickoff(tagptr_cast_ptr(bi_private), nr_bios);
 	return true;
@@ -1019,6 +1284,9 @@ static void z_erofs_submit_and_unzip(struct z_erofs_vle_frontend *f,
 	if (!z_erofs_vle_submit_all(sb, f->owned_head, pagepool, io, force_fg))
 		return;
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+	z_erofs_vle_unzip_all(sb, &io[0], pagepool);
+#endif
 	if (!force_fg)
 		return;
 
@@ -1038,6 +1306,9 @@ static int z_erofs_vle_normalaccess_readpage(struct file *file,
 	int err;
 	LIST_HEAD(pagepool);
 
+#if (EROFS_FS_ZIP_CACHE_LVL >= 2)
+	f.cachedzone_la = page->index << PAGE_SHIFT;
+#endif
 	err = z_erofs_do_read_page(&f, page, &pagepool);
 	(void)z_erofs_vle_work_iter_end(&f.builder);
 
@@ -1068,6 +1339,9 @@ static inline int __z_erofs_vle_normalaccess_readpages(
 	struct page *head = NULL;
 	LIST_HEAD(pagepool);
 
+#if (EROFS_FS_ZIP_CACHE_LVL >= 2)
+	f.cachedzone_la = lru_to_page(pages)->index << PAGE_SHIFT;
+#endif
 	for (; nr_pages; --nr_pages) {
 		struct page *page = lru_to_page(pages);
 
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index 6530035..ee70bb9 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -143,13 +143,28 @@ unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
 		if (cleanup)
 			BUG_ON(cnt != 1);
 
+#ifndef EROFS_FS_HAS_MANAGED_CACHE
 		else if (cnt > 1)
+#else
+		if (!erofs_workgroup_try_to_freeze(grp, 1))
+#endif
 			continue;
 
 		if (radix_tree_delete(&sbi->workstn_tree,
-			grp->index) != grp)
+			grp->index) != grp) {
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+skip:
+			erofs_workgroup_unfreeze(grp, 1);
+#endif
 			continue;
+		}
 
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+		if (try_to_free_all_cached_pages(sbi, grp))
+			goto skip;
+
+		erofs_workgroup_unfreeze(grp, 1);
+#endif
 		/* (rarely) grabbed again when freeing */
 		erofs_workgroup_put(grp);
 
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 25/25] staging: erofs: add a TODO and update MAINTAINERS for staging
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (23 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 24/25] staging: erofs: introduce cached decompression Gao Xiang
@ 2018-07-26 12:22   ` Gao Xiang
  2018-07-28  7:10     ` [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES Gao Xiang
  2018-07-27  0:25   ` [PATCH 00/25] staging: erofs: introduce erofs file system Christian Kujau
  2018-07-28  7:25   ` Greg Kroah-Hartman
  26 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-07-26 12:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-fsdevel, linux-kernel, linux-erofs, yuchao0, miaoxie,
	weidu.du, hsiangkao, chao, Gao Xiang

This patch adds a TODO to list the things to be done, and
the relevant info to MAINTAINERS so we can take all the blame :)

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 MAINTAINERS                |  7 +++++++
 drivers/staging/erofs/TODO | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 drivers/staging/erofs/TODO

diff --git a/MAINTAINERS b/MAINTAINERS
index 0fe4228..8d470b0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13487,6 +13487,13 @@ M:	H Hartley Sweeten <hsweeten@visionengravers.com>
 S:	Odd Fixes
 F:	drivers/staging/comedi/
 
+STAGING - EROFS FILE SYSTEM
+M:	Gao Xiang <gaoxiang25@huawei.com>
+M:	Chao Yu <yuchao0@huawei.com>
+L:	linux-erofs@lists.ozlabs.org
+S:	Maintained
+F:	drivers/staging/erofs/
+
 STAGING - FLARION FT1000 DRIVERS
 M:	Marek Belisko <marek.belisko@gmail.com>
 S:	Odd Fixes
diff --git a/drivers/staging/erofs/TODO b/drivers/staging/erofs/TODO
new file mode 100644
index 0000000..f99ddb8
--- /dev/null
+++ b/drivers/staging/erofs/TODO
@@ -0,0 +1,45 @@
+
+EROFS is still working in progress, thus it is not suitable
+for all productive uses. play at your own risk :)
+
+TODO List:
+ - add the missing error handling code
+   (mainly existed in xattr and decompression submodules);
+
+ - finalize erofs ondisk format design  (which means that
+   minor on-disk revisions could happen later);
+
+ - documentation and detailed technical analysis;
+
+ - general code review and clean up
+   (including confusing variable names and code snippets);
+
+ - support larger compressed clustersizes for selection
+   (currently erofs only works as expected with the page-sized
+    compressed cluster configuration, usually 4KB);
+
+ - support more lossless data compression algorithms
+   in addition to LZ4 algorithms in VLE approach;
+
+ - data deduplication and other useful features.
+
+erofs-mkfs (preview version) binaries for i386 / x86_64 are available at:
+
+   https://github.com/hsiangkao/erofs_mkfs_binary
+
+It is still in progress opening mkfs source code to public,
+in any case an open-source mkfs will be released in the near future.
+
+
+Code, suggestions, etc, are welcome. Please feel free to
+ask and send patches,
+
+To:
+  linux-erofs mailing list   <linux-erofs@lists.ozlabs.org>
+  Gao Xiang                  <gaoxiang25@huawei.com>
+  Chao Yu                    <yuchao0@huawei.com>
+
+Cc: (for linux-kernel upstream patches)
+  Greg Kroah-Hartman         <gregkh@linuxfoundation.org>
+  linux-staging mailing list <devel@driverdev.osuosl.org>
+
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (24 preceding siblings ...)
  2018-07-26 12:22   ` [PATCH 25/25] staging: erofs: add a TODO and update MAINTAINERS for staging Gao Xiang
@ 2018-07-27  0:25   ` Christian Kujau
  2018-07-27  1:39     ` Gao Xiang
  2018-07-28  7:25   ` Greg Kroah-Hartman
  26 siblings, 1 reply; 58+ messages in thread
From: Christian Kujau @ 2018-07-27  0:25 UTC (permalink / raw)
  To: Gao Xiang; +Cc: linux-kernel

On Thu, 26 Jul 2018, Gao Xiang wrote:
> EROFS file system is a read-only file system with compression
> support designed for certain devices (especially embeded
> devices) with very limited physical memory and lots of memory

Out of curiousity, and as Richard already asked[0] - what about existing 
file system, why can't they be used or extended instead of introducing yet 
another file system into the kernel? JFFS2? UBIFS? CramFs? SquashFS? 
ROMFS? F2FS? YAFFS?

Christian.

[0] https://marc.info/?l=linux-kernel&m=152783930418348&w=2
-- 
BOFH excuse #247:

Due to Federal Budget problems we have been forced to cut back on the number of users able to access the system at one time. (namely none allowed....)

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-06-01  9:28     ` Richard Weinberger
  2018-06-01 11:16       ` Gao Xiang
@ 2018-07-27  0:55       ` Joey Pabalinas
  2018-07-27  0:57         ` Joey Pabalinas
  1 sibling, 1 reply; 58+ messages in thread
From: Joey Pabalinas @ 2018-07-27  0:55 UTC (permalink / raw)
  To: Richard Weinberger
  Cc: Gao Xiang, LKML, linux-fsdevel, miaoxie, yuchao0, sunqiuyang,
	fangwei1, liguifu2, weidu.du, chen.chun.yen, brooke.wangzhigang,
	dongjinguang, Joey Pabalinas

[-- Attachment #1: Type: text/plain, Size: 432 bytes --]

On Fri, Jun 01, 2018 at 11:28:07AM +0200, Richard Weinberger wrote:
> > We also think of other candidate full names, such as
> > Enhanced / Extented Read-only File System, all the names short for "erofs" are okay.
> 
> TBH, I read "erofs" as "error fs". ;-)

I thought the exact same thing; opened the thread and was a bit confused
at first. In my opinion the name feels slightly misleading.

-- 
Cheers,
Joey Pabalinas

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system
  2018-07-27  0:55       ` Joey Pabalinas
@ 2018-07-27  0:57         ` Joey Pabalinas
  0 siblings, 0 replies; 58+ messages in thread
From: Joey Pabalinas @ 2018-07-27  0:57 UTC (permalink / raw)
  To: Joey Pabalinas
  Cc: Richard Weinberger, Gao Xiang, LKML, linux-fsdevel, miaoxie,
	yuchao0, sunqiuyang, fangwei1, liguifu2, weidu.du, chen.chun.yen,
	brooke.wangzhigang, dongjinguang

[-- Attachment #1: Type: text/plain, Size: 370 bytes --]

On Thu, Jul 26, 2018 at 02:55:11PM -1000, Joey Pabalinas wrote:
> I thought the exact same thing; opened the thread and was a bit confused
> at first. In my opinion the name feels slightly misleading.

Oooh, reading more of the thread I see there is some fun wordplay going
on which I didn't catch at first. I rescind my comment :)

-- 
Cheers,
Joey Pabalinas

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-27  0:25   ` [PATCH 00/25] staging: erofs: introduce erofs file system Christian Kujau
@ 2018-07-27  1:39     ` Gao Xiang
  2018-07-27  1:56       ` Gao Xiang
  0 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-07-27  1:39 UTC (permalink / raw)
  To: Christian Kujau; +Cc: linux-kernel, linux-erofs

Hi Christian, 

On 2018/7/27 8:25, Christian Kujau wrote:
> On Thu, 26 Jul 2018, Gao Xiang wrote:
>> EROFS file system is a read-only file system with compression
>> support designed for certain devices (especially embeded
>> devices) with very limited physical memory and lots of memory
> Out of curiousity, and as Richard already asked[0] - what about existing 
> file system, why can't they be used or extended instead of introducing yet 
> another file system into the kernel? JFFS2? UBIFS? CramFs? SquashFS? 
> ROMFS? F2FS? YAFFS?
> 
> Christian.
> 

Every file system has its typical usage case.

I don't think there exists a silver bullet solving all usage cases optimally.
JFFS2, YAFFS and UBIFS are designed for raw flash, we use UFS or eMMC solution
rather than raw nand flash.

Cramfs and ROMFS are too simple for us, and it is actually useless because no
similar & duplicate code with EROFS.

We can save about 200MB+ metadata space than EXT4 by just using EROFS
_without_ compression support in our products, which could be more compared
with F2FS(F2FS has more useless metadata for read-only use such as SIT, and SSA).
Since we are a read-only file system, we could use aggressive inline(compact) and data
deduplication approach. It is not a small number storage space because we
leave some compression ratio for better performance in low memory scenario.

and I don't think SquashFS is optimal for us, 1) it doesn't have the inline
consideration by design (inline could save storage space also reduce extra data IOs),
2) it is designed for saving more storage space rather than keeping high performance
for limited physical memory scenario; 3) it has many compatible code for its historial
design, actually its on-disk layout design is hard to be extended considering its
historial images 4) It is not designed for VLE, we need to rewrite more than half of
its current code 5) EROFS has no similar code with the current SquashFS.

In the end, I don't think F2FS could be an expansion of NILFS2, BTRFS
is an b-tree expansion of some read-write file system. You could call EROFS
as ROMFS2 or Squashfs+ but EROFS is a completely different solution.
We need to evaluate the optimal file system for each specific usage case (actually
we think erofs almost reaches our requirements for our Android products rather
than SquashFS) and KISS for each solution.


Thanks for your reply :)

Thanks,
Gao Xiang

> [0] https://marc.info/?l=linux-kernel&m=152783930418348&w=2

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-27  1:39     ` Gao Xiang
@ 2018-07-27  1:56       ` Gao Xiang
  0 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-27  1:56 UTC (permalink / raw)
  To: Christian Kujau; +Cc: linux-kernel, linux-erofs, devel



On 2018/7/27 9:39, Gao Xiang wrote:
> Every file system has its typical usage case.
> 
> I don't think there exists a silver bullet solving all usage cases optimally.
> JFFS2, YAFFS and UBIFS are designed for raw flash, we use UFS or eMMC solution
> rather than raw nand flash.
> 
> Cramfs and ROMFS are too simple for us, and it is actually useless because no
> similar & duplicate code with EROFS.
> 
> We can save about 200MB+ metadata space than EXT4 by just using EROFS
> _without_ compression support in our products, which could be more compared
> with F2FS(F2FS has more useless metadata for read-only use such as SIT, and SSA).
> Since we are a read-only file system, we could use aggressive inline(compact) and data
> deduplication approach. It is not a small number storage space because we
> leave some compression ratio for better performance in low memory scenario.
> 
> and I don't think SquashFS is optimal for us, 1) it doesn't have the inline
> consideration by design (inline could save storage space also reduce extra data IOs),
> 2) it is designed for saving more storage space rather than keeping high performance
> for limited physical memory scenario; 3) it has many compatible code for its historial
> design, actually its on-disk layout design is hard to be extended considering its
> historial images 4) It is not designed for VLE, we need to rewrite more than half of
> its current code 5) EROFS has no similar code with the current SquashFS.
> > In the end, I don't think F2FS could be an expansion of NILFS2, BTRFS
> is an b-tree expansion of some read-write file system. You could call EROFS
> as ROMFS2 or Squashfs+ but EROFS is a completely different solution.
> We need to evaluate the optimal file system for each specific usage case (actually
> we think erofs almost reaches our requirements for our Android products rather
> than SquashFS) and KISS for each solution.

One more to say, if we could make a rather complicated final file system,
and you can imagine it has average or even worse performance, lots of limitation and
historial issues(just complicated as the C++ language), and hard to maintain
by some individuals and debug.

Thanks,
Gao Xiang

^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES
  2018-07-26 12:22   ` [PATCH 25/25] staging: erofs: add a TODO and update MAINTAINERS for staging Gao Xiang
@ 2018-07-28  7:10     ` Gao Xiang
  2018-07-28 10:43       ` Chao Yu
  2018-07-29  5:34       ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Gao Xiang
  0 siblings, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-28  7:10 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-kernel, linux-erofs, Chao Yu, Miao Xie, weidu.du, Gao Xiang

There is a type mismatch in the definition of
Z_EROFS_VLE_VMAP_ONSTACK_PAGES, let's fix it.

Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050707.html
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/unzip_vle.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/unzip_vle.h b/drivers/staging/erofs/unzip_vle.h
index 3521dfb..3939985 100644
--- a/drivers/staging/erofs/unzip_vle.h
+++ b/drivers/staging/erofs/unzip_vle.h
@@ -218,7 +218,7 @@ static inline void z_erofs_onlinepage_endio(struct page *page)
 }
 
 #define Z_EROFS_VLE_VMAP_ONSTACK_PAGES	\
-	min(THREAD_SIZE / 8 / sizeof(struct page *), 96UL)
+	min_t(unsigned int, THREAD_SIZE / 8 / sizeof(struct page *), 96U)
 #define Z_EROFS_VLE_VMAP_GLOBAL_PAGES	2048
 
 /* unzip_vle_lz4.c */
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
                     ` (25 preceding siblings ...)
  2018-07-27  0:25   ` [PATCH 00/25] staging: erofs: introduce erofs file system Christian Kujau
@ 2018-07-28  7:25   ` Greg Kroah-Hartman
  2018-07-28  9:33     ` Gao Xiang
  2018-07-28 10:34     ` Chao Yu
  26 siblings, 2 replies; 58+ messages in thread
From: Greg Kroah-Hartman @ 2018-07-28  7:25 UTC (permalink / raw)
  To: Gao Xiang
  Cc: devel, hsiangkao, linux-erofs, yuchao0, linux-kernel, weidu.du,
	linux-fsdevel, miaoxie, chao

On Thu, Jul 26, 2018 at 08:21:43PM +0800, Gao Xiang wrote:
> Hi,
> 
> This is actually the 2nd patchset of erofs file system,
> the original patchset can be found at
> 
> Link: https://marc.info/?l=linux-fsdevel&m=152776480425624
> 
> In order to keep up with the mainline linux-kernel changes and
> improve it in a more active and timely manner, we put forword
> this upstream proposal for linux-staging.
> 
> EROFS file system is a read-only file system with compression
> support designed for certain devices (especially embeded
> devices) with very limited physical memory and lots of memory
> consumers, such as Android devices. It aimes to provide
> a complete compression solution for such devices focuing
> on high performance and little extra memory overhead.
> 
> It is perferred to select larger compressed cluster sizes
> (generally >= 128k) for traditional compression file systems.
> It reads and decompresses a large compressed cluster at once,
> which has a good-looking random read number when memory
> is sufficient because all historial decompressed data
> is expected to be cached in memory. However, it also
> induces destructive effects when such devices have no enough
> spare memory for caching and decompression.
> 
> EROFS file system acts in some different way. It uses
> fixed-sized compressed size rather than fixed-sized input
> size, namely VLE (variable-length extent) compression,
> which has at least three adventages:
> 
>  1) all data read from block device at once can be
>     utilized, and read amplification can be easier to
>     estimate and control;
>  2) generally, it has a better compression ratio than
>     fixed-sized input compression approaches configured
>     with the same size;
>  3) aggressively optimized paths such as partial page
>     read can be implemented to gain better performance
>     for page-unaligned read (unimplemented yet, in TODO list).
> 
> As can be seen, VLE compression does a great job in small
> compressed cluster sizes, which is of course suitable for
> devices with limited memory. In this patchset, an in-place
> decompresion is also introduced to minimize extra memory usage.
> 
> 
> Apart from compression, EROFS also has the following features
> available and some limits:
>  o page-sized block support (currently, and no buffer-head);
>  o 32-bit block address (16TB for 4KB block);
>  o selectable v1 (32 bytes) / v2 (64 bytes) inode;
>  o 32-bit / 64-bit file size;
>  o 64-bit node number for addressing inodes;
>  o 64-bit s and 32-bit ns timestamps;
>  o inline data support;
>  o inline and shared xattr support;
>  o metadata and data can be mixed (optional);
>  o special inode support;
>  o posix acl support.
> 
> 
> The file system is still actively WIP, see _TODO_ for more details.
> 
> Any comments are welcome. :)

Thanks for submitting this, the filesystem looks very interesting.  I've
queued it all up now in the staging-next tree.

greg k-h

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-28  7:25   ` Greg Kroah-Hartman
@ 2018-07-28  9:33     ` Gao Xiang
  2018-07-28 10:34     ` Chao Yu
  1 sibling, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-28  9:33 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: devel, hsiangkao, linux-erofs, yuchao0, linux-kernel, weidu.du,
	linux-fsdevel, miaoxie, chao



On 2018/7/28 15:25, Greg Kroah-Hartman wrote:
> Thanks for submitting this, the filesystem looks very interesting.  I've
> queued it all up now in the staging-next tree.

Thanks for applying, we are continuously optimizing further and hope to attract more fs guys :)

Thanks,
Gao Xiang

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 00/25] staging: erofs: introduce erofs file system
  2018-07-28  7:25   ` Greg Kroah-Hartman
  2018-07-28  9:33     ` Gao Xiang
@ 2018-07-28 10:34     ` Chao Yu
  1 sibling, 0 replies; 58+ messages in thread
From: Chao Yu @ 2018-07-28 10:34 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Gao Xiang
  Cc: devel, hsiangkao, linux-erofs, linux-kernel, weidu.du,
	linux-fsdevel, miaoxie, chao

Hello Greg,

On 2018/7/28 15:25, Greg Kroah-Hartman wrote:
> 
> Thanks for submitting this, the filesystem looks very interesting.  I've
> queued it all up now in the staging-next tree.

Thanks very much for queuing erofs filesystem, that's actually excellent news
for us that it can be upstreamed so quickly, I think it will help to attract
more developers or users' attention on the filesystem, it should be beneficial
to its growing. Anyway, hoping it can bring something different on experience of
user in linux. :)

Thanks,

> 
> greg k-h
> 
> .
> 


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES
  2018-07-28  7:10     ` [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES Gao Xiang
@ 2018-07-28 10:43       ` Chao Yu
  2018-07-29  5:34       ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Gao Xiang
  1 sibling, 0 replies; 58+ messages in thread
From: Chao Yu @ 2018-07-28 10:43 UTC (permalink / raw)
  To: Gao Xiang, Greg Kroah-Hartman, devel
  Cc: linux-kernel, linux-erofs, Miao Xie, weidu.du

On 2018/7/28 15:10, Gao Xiang wrote:
> There is a type mismatch in the definition of
> Z_EROFS_VLE_VMAP_ONSTACK_PAGES, let's fix it.
> 
> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050707.html
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support
  2018-07-28  7:10     ` [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES Gao Xiang
  2018-07-28 10:43       ` Chao Yu
@ 2018-07-29  5:34       ` Gao Xiang
  2018-07-29  5:37         ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter Gao Xiang
  2018-07-30  2:07         ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Chao Yu
  1 sibling, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-29  5:34 UTC (permalink / raw)
  To: Chao Yu, Greg Kroah-Hartman
  Cc: linux-erofs, devel, linux-kernel, Gao Xiang, Gao Xiang

This patch fixes incorrect code snippets due to spilt code
into small patches by mistake.

Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050747.html
Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050750.html
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 I test several Kconfig option combinations and all these
combinations are successfully compiled.

Hi Chao,
 Could you please review this two patches first before merging
into staging-next tree?

Thanks,
Gao Xiang

 drivers/staging/erofs/internal.h  | 4 ++--
 drivers/staging/erofs/super.c     | 2 +-
 drivers/staging/erofs/unzip_vle.c | 7 ++++---
 drivers/staging/erofs/utils.c     | 7 ++++---
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 669f93ae6920..367b39fe46e5 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -260,9 +260,9 @@ static inline void erofs_workstation_cleanup_all(struct super_block *sb)
 #ifdef EROFS_FS_HAS_MANAGED_CACHE
 #define EROFS_UNALLOCATED_CACHED_PAGE	((void *)0x5F0EF00D)
 
-extern int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+extern int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 	struct erofs_workgroup *egrp);
-extern int try_to_free_cached_page(struct address_space *mapping,
+extern int erofs_try_to_free_cached_page(struct address_space *mapping,
 	struct page *page);
 #endif
 
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 97da5c8a8ef3..1aec509c805f 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -269,7 +269,7 @@ static int managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
 	BUG_ON(mapping->a_ops != &managed_cache_aops);
 
 	if (PagePrivate(page))
-		ret = try_to_free_cached_page(mapping, page);
+		ret = erofs_try_to_free_cached_page(mapping, page);
 
 	return ret;
 }
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 7671fe8194ce..0e410a228cd4 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -131,8 +131,8 @@ static bool grab_managed_cache_pages(struct address_space *mapping,
 }
 
 /* called by erofs_shrinker to get rid of all compressed_pages */
-int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
-				 struct erofs_workgroup *egrp)
+int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+				       struct erofs_workgroup *egrp)
 {
 	struct z_erofs_vle_workgroup *const grp =
 		container_of(egrp, struct z_erofs_vle_workgroup, obj);
@@ -166,7 +166,8 @@ int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 	return 0;
 }
 
-int try_to_free_cached_page(struct address_space *mapping, struct page *page)
+int erofs_try_to_free_cached_page(struct address_space *mapping,
+				  struct page *page)
 {
 	struct erofs_sb_info *const sbi = EROFS_SB(mapping->host->i_sb);
 	const unsigned int clusterpages = erofs_clusterpages(sbi);
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index ee70bb9e1636..595cf90af9bb 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -160,7 +160,7 @@ unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
 		}
 
 #ifdef EROFS_FS_HAS_MANAGED_CACHE
-		if (try_to_free_all_cached_pages(sbi, grp))
+		if (erofs_try_to_free_all_cached_pages(sbi, grp))
 			goto skip;
 
 		erofs_workgroup_unfreeze(grp, 1);
@@ -247,7 +247,9 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
 		spin_unlock(&erofs_sb_list_lock);
 		sbi->shrinker_run_no = run_no;
 
-		/* add scan handlers here */
+#ifdef CONFIG_EROFS_FS_ZIP
+		freed += erofs_shrink_workstation(sbi, nr, false);
+#endif
 
 		spin_lock(&erofs_sb_list_lock);
 		/* Get the next list element before we move this one */
@@ -260,7 +262,6 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
 		list_move_tail(&sbi->list, &erofs_sb_list);
 		mutex_unlock(&sbi->umount_mutex);
 
-		freed += erofs_shrink_workstation(sbi, nr, false);
 		if (freed >= nr)
 			break;
 	}
-- 
2.17.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter
  2018-07-29  5:34       ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Gao Xiang
@ 2018-07-29  5:37         ` Gao Xiang
  2018-07-30  1:51           ` [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code Gao Xiang
  2018-07-30  2:07           ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' " Chao Yu
  2018-07-30  2:07         ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Chao Yu
  1 sibling, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-29  5:37 UTC (permalink / raw)
  To: Chao Yu, Greg Kroah-Hartman
  Cc: linux-erofs, devel, linux-kernel, Gao Xiang, Gao Xiang

This patch adds error handling code for
z_erofs_map_blocks_iter to fix the compiler blame.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---

let's solve the compiler warning first, more error handling code
for other functions will be added in the future patch.

 drivers/staging/erofs/unzip_vle.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 0e410a228cd4..bd2d7a8d5085 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1532,13 +1532,14 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	unsigned long long ofs, end;
 	struct z_erofs_vle_decompressed_index *di;
 	erofs_blk_t e_blkaddr, pcn;
-	unsigned lcn, logical_cluster_ofs;
+	unsigned lcn, logical_cluster_ofs, cluster_type;
 	u32 ofs_rem;
 	struct page *mpage = *mpage_ret;
 	void *kaddr;
 	bool initial;
 	const unsigned int clusterbits = EROFS_SB(inode->i_sb)->clusterbits;
 	const unsigned int clustersize = 1 << clusterbits;
+	int err = 0;
 
 	/* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */
 	initial = !map->m_llen;
@@ -1592,7 +1593,9 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 
 	end = (u64)(lcn + 1) * clustersize;
 
-	switch (vle_cluster_type(di)) {
+	cluster_type = vle_cluster_type(di);
+
+	switch (cluster_type) {
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
 		if (ofs_rem >= logical_cluster_ofs)
 			map->m_flags ^= EROFS_MAP_ZIPPED;
@@ -1608,13 +1611,24 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 			break;
 		}
 
-		BUG_ON(!lcn);	/* logical cluster number >= 1 */
+		/* logical cluster number should be >= 1 */
+		if (unlikely(!lcn)) {
+			errln("invalid logical cluster 0 at nid %llu",
+				EROFS_V(inode)->nid);
+			err = -EIO;
+			goto unmap_out;
+		}
 		end = (lcn-- * clustersize) | logical_cluster_ofs;
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
 		ofs = vle_get_logical_extent_head(inode, mpage_ret,
 			&kaddr, lcn, &pcn, &map->m_flags);
 		mpage = *mpage_ret;
+	default:
+		errln("unknown cluster type %u at offset %llu of nid %llu",
+			cluster_type, ofs, EROFS_V(inode)->nid);
+		err = -EIO;
+		goto unmap_out;
 	}
 
 	map->m_la = ofs;
@@ -1630,6 +1644,9 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	debugln("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
 		__func__, map->m_la, map->m_pa,
 		map->m_llen, map->m_plen, map->m_flags);
-	return 0;
+
+	/* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
+	DBG_BUGON(err < 0);
+	return err;
 }
 
-- 
2.17.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code
  2018-07-29  5:37         ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter Gao Xiang
@ 2018-07-30  1:51           ` Gao Xiang
  2018-07-30  6:58             ` Chao Yu
  2018-08-01  6:38             ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Gao Xiang
  2018-07-30  2:07           ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' " Chao Yu
  1 sibling, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-30  1:51 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Chao Yu
  Cc: devel, linux-kernel, linux-erofs, Miao Xie, weidu.du, Gao Xiang

Just clean up and logic doesn't change.

Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050766.html
Fixes: d72d1ce60174 ("staging: erofs: add namei functions")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/namei.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
index d2a0da3..546a471 100644
--- a/drivers/staging/erofs/namei.c
+++ b/drivers/staging/erofs/namei.c
@@ -195,7 +195,7 @@ int erofs_namei(struct inode *dir,
 	kunmap_atomic(data);
 	put_page(page);
 
-	return IS_ERR(de) ? PTR_ERR(de) : 0;
+	return PTR_ERR_OR_ZERO(de);
 }
 
 /* NOTE: i_mutex is already held by vfs */
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support
  2018-07-29  5:34       ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Gao Xiang
  2018-07-29  5:37         ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter Gao Xiang
@ 2018-07-30  2:07         ` Chao Yu
  2018-07-30  2:32           ` Gao Xiang
  1 sibling, 1 reply; 58+ messages in thread
From: Chao Yu @ 2018-07-30  2:07 UTC (permalink / raw)
  To: Gao Xiang, Chao Yu, Greg Kroah-Hartman; +Cc: devel, linux-erofs, linux-kernel

On 2018/7/29 13:34, Gao Xiang via Linux-erofs wrote:
> This patch fixes incorrect code snippets due to spilt code
> into small patches by mistake.
> 
> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050747.html
> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050750.html
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
> ---
>  I test several Kconfig option combinations and all these
> combinations are successfully compiled.
> 
> Hi Chao,
>  Could you please review this two patches first before merging
> into staging-next tree?

Hi Xiang,

For this compiler issue, I think we only need to cover erofs_shrink_workstation
with marco CONFIG_EROFS_FS_ZIP, other modification like symbol name change or
relocate erofs_shrink_workstation are with other reason, so how about separate
them into different patches?

Thanks,

> 
> Thanks,
> Gao Xiang
> 
>  drivers/staging/erofs/internal.h  | 4 ++--
>  drivers/staging/erofs/super.c     | 2 +-
>  drivers/staging/erofs/unzip_vle.c | 7 ++++---
>  drivers/staging/erofs/utils.c     | 7 ++++---
>  4 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
> index 669f93ae6920..367b39fe46e5 100644
> --- a/drivers/staging/erofs/internal.h
> +++ b/drivers/staging/erofs/internal.h
> @@ -260,9 +260,9 @@ static inline void erofs_workstation_cleanup_all(struct super_block *sb)
>  #ifdef EROFS_FS_HAS_MANAGED_CACHE
>  #define EROFS_UNALLOCATED_CACHED_PAGE	((void *)0x5F0EF00D)
>  
> -extern int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
> +extern int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
>  	struct erofs_workgroup *egrp);
> -extern int try_to_free_cached_page(struct address_space *mapping,
> +extern int erofs_try_to_free_cached_page(struct address_space *mapping,
>  	struct page *page);
>  #endif
>  
> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
> index 97da5c8a8ef3..1aec509c805f 100644
> --- a/drivers/staging/erofs/super.c
> +++ b/drivers/staging/erofs/super.c
> @@ -269,7 +269,7 @@ static int managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
>  	BUG_ON(mapping->a_ops != &managed_cache_aops);
>  
>  	if (PagePrivate(page))
> -		ret = try_to_free_cached_page(mapping, page);
> +		ret = erofs_try_to_free_cached_page(mapping, page);
>  
>  	return ret;
>  }
> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
> index 7671fe8194ce..0e410a228cd4 100644
> --- a/drivers/staging/erofs/unzip_vle.c
> +++ b/drivers/staging/erofs/unzip_vle.c
> @@ -131,8 +131,8 @@ static bool grab_managed_cache_pages(struct address_space *mapping,
>  }
>  
>  /* called by erofs_shrinker to get rid of all compressed_pages */
> -int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
> -				 struct erofs_workgroup *egrp)
> +int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
> +				       struct erofs_workgroup *egrp)
>  {
>  	struct z_erofs_vle_workgroup *const grp =
>  		container_of(egrp, struct z_erofs_vle_workgroup, obj);
> @@ -166,7 +166,8 @@ int try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
>  	return 0;
>  }
>  
> -int try_to_free_cached_page(struct address_space *mapping, struct page *page)
> +int erofs_try_to_free_cached_page(struct address_space *mapping,
> +				  struct page *page)
>  {
>  	struct erofs_sb_info *const sbi = EROFS_SB(mapping->host->i_sb);
>  	const unsigned int clusterpages = erofs_clusterpages(sbi);
> diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
> index ee70bb9e1636..595cf90af9bb 100644
> --- a/drivers/staging/erofs/utils.c
> +++ b/drivers/staging/erofs/utils.c
> @@ -160,7 +160,7 @@ unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
>  		}
>  
>  #ifdef EROFS_FS_HAS_MANAGED_CACHE
> -		if (try_to_free_all_cached_pages(sbi, grp))
> +		if (erofs_try_to_free_all_cached_pages(sbi, grp))
>  			goto skip;
>  
>  		erofs_workgroup_unfreeze(grp, 1);
> @@ -247,7 +247,9 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
>  		spin_unlock(&erofs_sb_list_lock);
>  		sbi->shrinker_run_no = run_no;
>  
> -		/* add scan handlers here */
> +#ifdef CONFIG_EROFS_FS_ZIP
> +		freed += erofs_shrink_workstation(sbi, nr, false);
> +#endif
>  
>  		spin_lock(&erofs_sb_list_lock);
>  		/* Get the next list element before we move this one */
> @@ -260,7 +262,6 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
>  		list_move_tail(&sbi->list, &erofs_sb_list);
>  		mutex_unlock(&sbi->umount_mutex);
>  
> -		freed += erofs_shrink_workstation(sbi, nr, false);
>  		if (freed >= nr)
>  			break;
>  	}
> 


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter
  2018-07-29  5:37         ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter Gao Xiang
  2018-07-30  1:51           ` [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code Gao Xiang
@ 2018-07-30  2:07           ` Chao Yu
  1 sibling, 0 replies; 58+ messages in thread
From: Chao Yu @ 2018-07-30  2:07 UTC (permalink / raw)
  To: Gao Xiang, Chao Yu, Greg Kroah-Hartman; +Cc: devel, linux-erofs, linux-kernel

On 2018/7/29 13:37, Gao Xiang via Linux-erofs wrote:
> This patch adds error handling code for
> z_erofs_map_blocks_iter to fix the compiler blame.
> 
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support
  2018-07-30  2:07         ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Chao Yu
@ 2018-07-30  2:32           ` Gao Xiang
  2018-07-30  3:07             ` Chao Yu
  0 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-07-30  2:32 UTC (permalink / raw)
  To: Chao Yu, Greg Kroah-Hartman, Chao Yu, Gao Xiang
  Cc: devel, linux-erofs, linux-kernel

Hi Chao,

On 2018/7/30 10:07, Chao Yu wrote:
> On 2018/7/29 13:34, Gao Xiang via Linux-erofs wrote:
>> This patch fixes incorrect code snippets due to spilt code
>> into small patches by mistake.
>>
>> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050747.html
>> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050750.html
>> Reported-by: kbuild test robot <lkp@intel.com>
>> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
>> ---
>>  I test several Kconfig option combinations and all these
>> combinations are successfully compiled.
>>
>> Hi Chao,
>>  Could you please review this two patches first before merging
>> into staging-next tree?
> Hi Xiang,
> 
> For this compiler issue, I think we only need to cover erofs_shrink_workstation
> with marco CONFIG_EROFS_FS_ZIP, other modification like symbol name change or
> relocate erofs_shrink_workstation are with other reason, so how about separate
> them into different patches?
> 
> Thanks,
> 

It seems that Greg merged this patch to staging-next yesterday, since it is a urgent fix
(otherwise erofs cannot be compiled properly without CONFIG_EROFS_FS_ZIP, that is my fault).

I wrote in a patch yesterday becuase all the modifications have the same root cause ----
    fix incorrect code snippets due to spilt code into small patches by mistake.

But you are right, it is more proper to spilt into two patches, let me resend these patches later
(I don't know whether Greg will apply them... :-( sorry... )

I think in order to reduce Greg's patchwork burden, we could quickly review patches internally in linux-erofs first,
tidy up in a patchset set and send to Greg in a series periodically (if patches are not urgent).

How do you think about it?

Thanks,
Gao Xiang

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support
  2018-07-30  2:32           ` Gao Xiang
@ 2018-07-30  3:07             ` Chao Yu
  2018-07-30  3:55               ` Gao Xiang
  0 siblings, 1 reply; 58+ messages in thread
From: Chao Yu @ 2018-07-30  3:07 UTC (permalink / raw)
  To: Gao Xiang, Greg Kroah-Hartman, Chao Yu, Gao Xiang
  Cc: devel, linux-erofs, linux-kernel

Hi Xiang,

On 2018/7/30 10:32, Gao Xiang wrote:
> Hi Chao,
> 
> On 2018/7/30 10:07, Chao Yu wrote:
>> On 2018/7/29 13:34, Gao Xiang via Linux-erofs wrote:
>>> This patch fixes incorrect code snippets due to spilt code
>>> into small patches by mistake.
>>>
>>> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050747.html
>>> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050750.html
>>> Reported-by: kbuild test robot <lkp@intel.com>
>>> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
>>> ---
>>>  I test several Kconfig option combinations and all these
>>> combinations are successfully compiled.
>>>
>>> Hi Chao,
>>>  Could you please review this two patches first before merging
>>> into staging-next tree?
>> Hi Xiang,
>>
>> For this compiler issue, I think we only need to cover erofs_shrink_workstation
>> with marco CONFIG_EROFS_FS_ZIP, other modification like symbol name change or
>> relocate erofs_shrink_workstation are with other reason, so how about separate
>> them into different patches?
>>
>> Thanks,
>>
> 
> It seems that Greg merged this patch to staging-next yesterday, since it is a urgent fix
> (otherwise erofs cannot be compiled properly without CONFIG_EROFS_FS_ZIP, that is my fault).
> 
> I wrote in a patch yesterday becuase all the modifications have the same root cause ----
>     fix incorrect code snippets due to spilt code into small patches by mistake.
> 
> But you are right, it is more proper to spilt into two patches, let me resend these patches later
> (I don't know whether Greg will apply them... :-( sorry... )
> 
> I think in order to reduce Greg's patchwork burden, we could quickly review patches internally in linux-erofs first,
> tidy up in a patchset set and send to Greg in a series periodically (if patches are not urgent).
> 
> How do you think about it?

I agree with you, as we discussed offline, let's send patch to erofs mailing
list for review first, and keep all developing patches in erofs-dev branch as
long as possible, then periodically, submitting patches to Greg in batch, it can
reduce unneeded modification in staging-next tree. For urgent fix, we can speed
up the progress. :)

Thanks,

> 
> Thanks,
> Gao Xiang
> 
> .
> 


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support
  2018-07-30  3:07             ` Chao Yu
@ 2018-07-30  3:55               ` Gao Xiang
  0 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-07-30  3:55 UTC (permalink / raw)
  To: Chao Yu, Greg Kroah-Hartman, Chao Yu, Gao Xiang
  Cc: devel, linux-erofs, linux-kernel


On 2018/7/30 11:07, Chao Yu wrote:
>> It seems that Greg merged this patch to staging-next yesterday, since it is a urgent fix
>> (otherwise erofs cannot be compiled properly without CONFIG_EROFS_FS_ZIP, that is my fault).
>>
>> I wrote in a patch yesterday becuase all the modifications have the same root cause ----
>>     fix incorrect code snippets due to spilt code into small patches by mistake.
>>
>> But you are right, it is more proper to spilt into two patches, let me resend these patches later
>> (I don't know whether Greg will apply them... :-( sorry... )
>>
>> I think in order to reduce Greg's patchwork burden, we could quickly review patches internally in linux-erofs first,
>> tidy up in a patchset set and send to Greg in a series periodically (if patches are not urgent).
>>
>> How do you think about it?
> I agree with you, as we discussed offline, let's send patch to erofs mailing
> list for review first, and keep all developing patches in erofs-dev branch as
> long as possible, then periodically, submitting patches to Greg in batch, it can
> reduce unneeded modification in staging-next tree. For urgent fix, we can speed
> up the progress. :)
> 
> Thanks,
> 

Hi Greg,
Sorry about patch annoying... We will send patches in batch periodically after
"[PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code".

Before that, We will review these patches in the linux-erofs mailing list first...


Hi Chao,
OK, I just send new patches as your suggestion, could you please review again?
(But I think it could not be re-merged by Greg's again... since no code changes,
but the following patches will be upstreamed as we disscussed this morning...)


And could you review '[PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code'
I just sent in the morning?


Thanks,
Gao Xiang

^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code
  2018-07-30  1:51           ` [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code Gao Xiang
@ 2018-07-30  6:58             ` Chao Yu
  2018-08-01  6:38             ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Gao Xiang
  1 sibling, 0 replies; 58+ messages in thread
From: Chao Yu @ 2018-07-30  6:58 UTC (permalink / raw)
  To: Gao Xiang, Greg Kroah-Hartman
  Cc: devel, linux-kernel, linux-erofs, Miao Xie, weidu.du

On 2018/7/30 9:51, Gao Xiang wrote:
> Just clean up and logic doesn't change.
> 
> Link: https://lists.01.org/pipermail/kbuild-all/2018-July/050766.html
> Fixes: d72d1ce60174 ("staging: erofs: add namei functions")
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Thanks,


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-07-30  1:51           ` [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code Gao Xiang
  2018-07-30  6:58             ` Chao Yu
@ 2018-08-01  6:38             ` Gao Xiang
  2018-08-01  6:38               ` [PATCH 2/2] staging: erofs: remove a redundant marco in xattr Gao Xiang
  2018-08-01  9:02               ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Dan Carpenter
  1 sibling, 2 replies; 58+ messages in thread
From: Gao Xiang @ 2018-08-01  6:38 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-kernel, linux-erofs, yuchao0, miaoxie, weidu.du, hsiangkao,
	chao, Gao Xiang

This patch adds a missing break after adding the default case.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---

Hi Greg,
There are two erofs bugfix & cleanup patches ready for staging-next upstream.
The original preview thread:
  https://lists.ozlabs.org/pipermail/linux-erofs/2018-July/000281.html
  https://lists.ozlabs.org/pipermail/linux-erofs/2018-August/000294.html 

With regard to linux-next conflicts, there are also patches to solve them.
Chao will send them in batch to Stephen later.

Thanks,
Gao Xiang

 drivers/staging/erofs/unzip_vle.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index bd2d7a8..6d3ab31 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1596,10 +1596,10 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	cluster_type = vle_cluster_type(di);
 
 	switch (cluster_type) {
-	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:	/* fallthrough */
 		if (ofs_rem >= logical_cluster_ofs)
 			map->m_flags ^= EROFS_MAP_ZIPPED;
-	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:	/* fallthrough */
 		if (ofs_rem == logical_cluster_ofs) {
 			pcn = le32_to_cpu(di->di_u.blkaddr);
 			goto exact_hitted;
@@ -1624,6 +1624,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		ofs = vle_get_logical_extent_head(inode, mpage_ret,
 			&kaddr, lcn, &pcn, &map->m_flags);
 		mpage = *mpage_ret;
+		break;
 	default:
 		errln("unknown cluster type %u at offset %llu of nid %llu",
 			cluster_type, ofs, EROFS_V(inode)->nid);
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH 2/2] staging: erofs: remove a redundant marco in xattr
  2018-08-01  6:38             ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Gao Xiang
@ 2018-08-01  6:38               ` Gao Xiang
  2018-08-01  9:02               ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Dan Carpenter
  1 sibling, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-08-01  6:38 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-kernel, linux-erofs, yuchao0, miaoxie, weidu.du, hsiangkao,
	chao, Gao Xiang

There is no need to '#if CONFIG_EROFS_FS_XATTR' in xattr.c,
let's remove it.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
 drivers/staging/erofs/xattr.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c
index b74b314..6b9685f 100644
--- a/drivers/staging/erofs/xattr.c
+++ b/drivers/staging/erofs/xattr.c
@@ -420,7 +420,6 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 };
 #endif
 
-#ifdef CONFIG_EROFS_FS_XATTR
 const struct xattr_handler *erofs_xattr_handlers[] = {
 	&erofs_xattr_user_handler,
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
@@ -433,7 +432,6 @@ static int erofs_xattr_generic_get(const struct xattr_handler *handler,
 #endif
 	NULL,
 };
-#endif
 
 struct listxattr_iter {
 	struct xattr_iter it;
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-08-01  6:38             ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Gao Xiang
  2018-08-01  6:38               ` [PATCH 2/2] staging: erofs: remove a redundant marco in xattr Gao Xiang
@ 2018-08-01  9:02               ` Dan Carpenter
  2018-08-01  9:19                 ` Gao Xiang
  1 sibling, 1 reply; 58+ messages in thread
From: Dan Carpenter @ 2018-08-01  9:02 UTC (permalink / raw)
  To: Gao Xiang
  Cc: Greg Kroah-Hartman, devel, yuchao0, linux-erofs, hsiangkao,
	linux-kernel, weidu.du, miaoxie, chao

On Wed, Aug 01, 2018 at 02:38:30PM +0800, Gao Xiang wrote:
> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
> index bd2d7a8..6d3ab31 100644
> --- a/drivers/staging/erofs/unzip_vle.c
> +++ b/drivers/staging/erofs/unzip_vle.c
> @@ -1596,10 +1596,10 @@ int z_erofs_map_blocks_iter(struct inode *inode,
>  	cluster_type = vle_cluster_type(di);
>  
>  	switch (cluster_type) {
> -	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
> +	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:	/* fallthrough */

This fallthrough comment is in the wrong place.  It should be at the end
where the break would have been.  Like this:

	switch (cluster_type) {
	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
		frob();
		frob();
		frob();
		/* fallthrough */
	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
		frob();

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-08-01  9:02               ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Dan Carpenter
@ 2018-08-01  9:19                 ` Gao Xiang
  2018-08-01  9:36                   ` [PATCH RESEND " Gao Xiang
  0 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-08-01  9:19 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Greg Kroah-Hartman, devel, yuchao0, linux-erofs, hsiangkao,
	linux-kernel, weidu.du, miaoxie, chao

Hi Dan,

On 2018/8/1 17:02, Dan Carpenter wrote:
> On Wed, Aug 01, 2018 at 02:38:30PM +0800, Gao Xiang wrote:
>> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
>> index bd2d7a8..6d3ab31 100644
>> --- a/drivers/staging/erofs/unzip_vle.c
>> +++ b/drivers/staging/erofs/unzip_vle.c
>> @@ -1596,10 +1596,10 @@ int z_erofs_map_blocks_iter(struct inode *inode,
>>  	cluster_type = vle_cluster_type(di);
>>  
>>  	switch (cluster_type) {
>> -	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
>> +	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:	/* fallthrough */
> This fallthrough comment is in the wrong place.  It should be at the end
> where the break would have been.  Like this:
> 
> 	switch (cluster_type) {
> 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
> 		frob();
> 		frob();
> 		frob();
> 		/* fallthrough */
> 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
> 		frob();
> 

I am sorry.. I will send a new patch.
Thanks for your reply...

Thanks,
Gao Xiang

> regards,
> dan carpenter
> 

^ permalink raw reply	[flat|nested] 58+ messages in thread

* [PATCH RESEND 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-08-01  9:19                 ` Gao Xiang
@ 2018-08-01  9:36                   ` Gao Xiang
  2018-08-01 11:36                     ` Dan Carpenter
  0 siblings, 1 reply; 58+ messages in thread
From: Gao Xiang @ 2018-08-01  9:36 UTC (permalink / raw)
  To: Greg Kroah-Hartman, devel
  Cc: linux-kernel, linux-erofs, yuchao0, miaoxie, weidu.du, hsiangkao,
	chao, Gao Xiang

This patch adds a missing break after adding the default case.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
As pointed out by Dan Carpenter:
 - fix the wrong place of fallthrough comments

 drivers/staging/erofs/unzip_vle.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index bd2d7a8..1030ca5 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1599,6 +1599,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
 		if (ofs_rem >= logical_cluster_ofs)
 			map->m_flags ^= EROFS_MAP_ZIPPED;
+		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
 		if (ofs_rem == logical_cluster_ofs) {
 			pcn = le32_to_cpu(di->di_u.blkaddr);
@@ -1619,11 +1620,13 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 			goto unmap_out;
 		}
 		end = (lcn-- * clustersize) | logical_cluster_ofs;
+		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
 		ofs = vle_get_logical_extent_head(inode, mpage_ret,
 			&kaddr, lcn, &pcn, &map->m_flags);
 		mpage = *mpage_ret;
+		break;
 	default:
 		errln("unknown cluster type %u at offset %llu of nid %llu",
 			cluster_type, ofs, EROFS_V(inode)->nid);
-- 
1.9.1


^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH RESEND 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-08-01  9:36                   ` [PATCH RESEND " Gao Xiang
@ 2018-08-01 11:36                     ` Dan Carpenter
  2018-08-01 12:08                       ` Gao Xiang
  0 siblings, 1 reply; 58+ messages in thread
From: Dan Carpenter @ 2018-08-01 11:36 UTC (permalink / raw)
  To: Gao Xiang
  Cc: Greg Kroah-Hartman, devel, yuchao0, linux-erofs, hsiangkao,
	linux-kernel, weidu.du, miaoxie, chao

On Wed, Aug 01, 2018 at 05:36:54PM +0800, Gao Xiang wrote:
> This patch adds a missing break after adding the default case.
> 
> Reviewed-by: Chao Yu <yuchao0@huawei.com>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
> ---
> As pointed out by Dan Carpenter:
>  - fix the wrong place of fallthrough comments

Thanks.  Looks good.  Next time use [PATCH v2] instead of RESEND.  The
word RESEND basically means you are resending a patch exactly the same
as it was before.  You would only need to do that if we accidentally
deleted your first patch or whatever...

regards,
dan carpenter



^ permalink raw reply	[flat|nested] 58+ messages in thread

* Re: [PATCH RESEND 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter
  2018-08-01 11:36                     ` Dan Carpenter
@ 2018-08-01 12:08                       ` Gao Xiang
  0 siblings, 0 replies; 58+ messages in thread
From: Gao Xiang @ 2018-08-01 12:08 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Greg Kroah-Hartman, devel, yuchao0, linux-erofs, hsiangkao,
	linux-kernel, weidu.du, miaoxie, chao

Hi Dan,

On 2018/8/1 19:36, Dan Carpenter wrote:
> On Wed, Aug 01, 2018 at 05:36:54PM +0800, Gao Xiang wrote:
>> This patch adds a missing break after adding the default case.
>>
>> Reviewed-by: Chao Yu <yuchao0@huawei.com>
>> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
>> ---
>> As pointed out by Dan Carpenter:
>>  - fix the wrong place of fallthrough comments
> Thanks.  Looks good.  Next time use [PATCH v2] instead of RESEND.  The
> word RESEND basically means you are resending a patch exactly the same
> as it was before.  You would only need to do that if we accidentally
> deleted your first patch or whatever...
> 
> regards,
> dan carpenter
> 
> 
OK, it should not be titled RESEND, and I will take care the next time.
Thanks for taking the time to review :)

Thanks,
Gao Xiang

^ permalink raw reply	[flat|nested] 58+ messages in thread

end of thread, other threads:[~2018-08-01 12:09 UTC | newest]

Thread overview: 58+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-05-31 11:06 [NOMERGE] [RFC PATCH 00/12] erofs: introduce erofs file system Gao Xiang
2018-06-01  7:48 ` Richard Weinberger
2018-06-01  9:11   ` Gao Xiang
2018-06-01  9:28     ` Richard Weinberger
2018-06-01 11:16       ` Gao Xiang
2018-06-07 10:26         ` Pavel Machek
2018-07-27  0:55       ` Joey Pabalinas
2018-07-27  0:57         ` Joey Pabalinas
2018-07-26 12:21 ` [PATCH 00/25] staging: " Gao Xiang
2018-07-26 12:21   ` [PATCH 01/25] staging: erofs: add on-disk layout Gao Xiang
2018-07-26 12:21   ` [PATCH 02/25] staging: erofs: add erofs in-memory stuffs Gao Xiang
2018-07-26 12:21   ` [PATCH 03/25] staging: erofs: add super block operations Gao Xiang
2018-07-26 12:21   ` [PATCH 04/25] staging: erofs: add raw address_space operations Gao Xiang
2018-07-26 12:21   ` [PATCH 05/25] staging: erofs: add inode operations Gao Xiang
2018-07-26 12:21   ` [PATCH 06/25] staging: erofs: add directory operations Gao Xiang
2018-07-26 12:21   ` [PATCH 07/25] staging: erofs: add namei functions Gao Xiang
2018-07-26 12:21   ` [PATCH 08/25] staging: erofs: update Kconfig and Makefile Gao Xiang
2018-07-26 12:21   ` [PATCH 09/25] staging: erofs: introduce xattr & acl support Gao Xiang
2018-07-26 12:21   ` [PATCH 10/25] staging: erofs: support special inode Gao Xiang
2018-07-26 12:21   ` [PATCH 11/25] staging: erofs: introduce error injection infrastructure Gao Xiang
2018-07-26 12:21   ` [PATCH 12/25] staging: erofs: support tracepoint Gao Xiang
2018-07-26 12:21   ` [PATCH 13/25] staging: erofs: <linux/tagptr.h>: introduce tagged pointer Gao Xiang
2018-07-26 12:21   ` [PATCH 14/25] staging: erofs: introduce pagevec for unzip subsystem Gao Xiang
2018-07-26 12:21   ` [PATCH 15/25] staging: erofs: add erofs_map_blocks_iter Gao Xiang
2018-07-26 12:21   ` [PATCH 16/25] staging: erofs: add erofs_allocpage Gao Xiang
2018-07-26 12:22   ` [PATCH 17/25] staging: erofs: globalize prepare_bio and __submit_bio Gao Xiang
2018-07-26 12:22   ` [PATCH 18/25] staging: erofs: introduce a customized LZ4 decompression Gao Xiang
2018-07-26 12:22   ` [PATCH 19/25] staging: erofs: add a generic z_erofs VLE decompressor Gao Xiang
2018-07-26 12:22   ` [PATCH 20/25] staging: erofs: introduce superblock registration Gao Xiang
2018-07-26 12:22   ` [PATCH 21/25] staging: erofs: introduce erofs shrinker Gao Xiang
2018-07-26 12:22   ` [PATCH 22/25] staging: erofs: introduce workstation for decompression Gao Xiang
2018-07-26 12:22   ` [PATCH 23/25] staging: erofs: introduce VLE decompression support Gao Xiang
2018-07-26 12:22   ` [PATCH 24/25] staging: erofs: introduce cached decompression Gao Xiang
2018-07-26 12:22   ` [PATCH 25/25] staging: erofs: add a TODO and update MAINTAINERS for staging Gao Xiang
2018-07-28  7:10     ` [PATCH] staging: erofs: fix a compile warning of Z_EROFS_VLE_VMAP_ONSTACK_PAGES Gao Xiang
2018-07-28 10:43       ` Chao Yu
2018-07-29  5:34       ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Gao Xiang
2018-07-29  5:37         ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' in z_erofs_map_blocks_iter Gao Xiang
2018-07-30  1:51           ` [PATCH] staging: erofs: use the wrapped PTR_ERR_OR_ZERO instead of open code Gao Xiang
2018-07-30  6:58             ` Chao Yu
2018-08-01  6:38             ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Gao Xiang
2018-08-01  6:38               ` [PATCH 2/2] staging: erofs: remove a redundant marco in xattr Gao Xiang
2018-08-01  9:02               ` [PATCH 1/2] staging: erofs: add the missing break in z_erofs_map_blocks_iter Dan Carpenter
2018-08-01  9:19                 ` Gao Xiang
2018-08-01  9:36                   ` [PATCH RESEND " Gao Xiang
2018-08-01 11:36                     ` Dan Carpenter
2018-08-01 12:08                       ` Gao Xiang
2018-07-30  2:07           ` [PATCH 2/2] staging: erofs: fix conditional uninitialized `pcn' " Chao Yu
2018-07-30  2:07         ` [PATCH 1/2] staging: erofs: fix compile error without built-in decompression support Chao Yu
2018-07-30  2:32           ` Gao Xiang
2018-07-30  3:07             ` Chao Yu
2018-07-30  3:55               ` Gao Xiang
2018-07-27  0:25   ` [PATCH 00/25] staging: erofs: introduce erofs file system Christian Kujau
2018-07-27  1:39     ` Gao Xiang
2018-07-27  1:56       ` Gao Xiang
2018-07-28  7:25   ` Greg Kroah-Hartman
2018-07-28  9:33     ` Gao Xiang
2018-07-28 10:34     ` Chao Yu

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