[PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[Tetsuhiro Kohada]

Remove 'rwoffset' in exfat_inode_info and replace it with the parameter(cpos) of exfat_readdir.
Since rwoffset of  is referenced only by exfat_readdir, it is not necessary a exfat_inode_info's member.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
---
 fs/exfat/dir.c      | 16 ++++++----------
 fs/exfat/exfat_fs.h |  2 --
 fs/exfat/file.c     |  2 --
 fs/exfat/inode.c    |  3 ---
 fs/exfat/super.c    |  1 -
 5 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index a9b13ae3f325..fa5bb72aa295 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -59,7 +59,7 @@ static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
 }
 
 /* read a directory entry from the opened directory */
-static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
+static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)
 {
 	int i, dentries_per_clu, dentries_per_clu_bits = 0;
 	unsigned int type, clu_offset;
@@ -70,7 +70,7 @@ static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
-	unsigned int dentry = ei->rwoffset & 0xFFFFFFFF;
+	unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
 	struct buffer_head *bh;
 
 	/* check if the given file ID is opened */
@@ -162,7 +162,7 @@ static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
 			ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
 			ei->hint_bmap.clu = clu.dir;
 
-			ei->rwoffset = ++dentry;
+			*cpos = EXFAT_DEN_TO_B(++dentry);
 			return 0;
 		}
 
@@ -178,7 +178,7 @@ static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
 	}
 
 	dir_entry->namebuf.lfn[0] = '\0';
-	ei->rwoffset = dentry;
+	*cpos = EXFAT_DEN_TO_B(dentry);
 	return 0;
 }
 
@@ -242,12 +242,10 @@ static int exfat_iterate(struct file *filp, struct dir_context *ctx)
 	if (err)
 		goto unlock;
 get_new:
-	ei->rwoffset = EXFAT_B_TO_DEN(cpos);
-
 	if (cpos >= i_size_read(inode))
 		goto end_of_dir;
 
-	err = exfat_readdir(inode, &de);
+	err = exfat_readdir(inode, &cpos, &de);
 	if (err) {
 		/*
 		 * At least we tried to read a sector.  Move cpos to next sector
@@ -262,13 +260,11 @@ static int exfat_iterate(struct file *filp, struct dir_context *ctx)
 		goto end_of_dir;
 	}
 
-	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
-
 	if (!nb->lfn[0])
 		goto end_of_dir;
 
 	i_pos = ((loff_t)ei->start_clu << 32) |
-		((ei->rwoffset - 1) & 0xffffffff);
+		(EXFAT_B_TO_DEN(cpos-1) & 0xffffffff);
 	tmp = exfat_iget(sb, i_pos);
 	if (tmp) {
 		inum = tmp->i_ino;
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 44dc04520175..e586daf5a2e7 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -263,8 +263,6 @@ struct exfat_inode_info {
 	 * the validation of hint_stat.
 	 */
 	unsigned int version;
-	/* file offset or dentry index for readdir */
-	loff_t rwoffset;
 
 	/* hint for cluster last accessed */
 	struct exfat_hint hint_bmap;
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 4831a39632a1..a92478eabfa4 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -208,8 +208,6 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 	/* hint information */
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
-	if (ei->rwoffset > new_size)
-		ei->rwoffset = new_size;
 
 	/* hint_stat will be used if this is directory. */
 	ei->hint_stat.eidx = 0;
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 7f90204adef5..70a33d4807c3 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -114,8 +114,6 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 	unsigned int local_clu_offset = clu_offset;
 	unsigned int num_to_be_allocated = 0, num_clusters = 0;
 
-	ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
-
 	if (EXFAT_I(inode)->i_size_ondisk > 0)
 		num_clusters =
 			EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk,
@@ -567,7 +565,6 @@ static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = info->start_clu;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;
-	ei->rwoffset = 0;
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->i_pos = 0;
 
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 3b6a1659892f..b29935a91b9b 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -342,7 +342,6 @@ static int exfat_read_root(struct inode *inode)
 	ei->flags = ALLOC_FAT_CHAIN;
 	ei->type = TYPE_DIR;
 	ei->version = 0;
-	ei->rwoffset = 0;
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = sbi->root_dir;
-- 
2.25.1

RE: [PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[Sungjong Seo]

> Remove 'rwoffset' in exfat_inode_info and replace it with the
> parameter(cpos) of exfat_readdir.
> Since rwoffset of  is referenced only by exfat_readdir, it is not
> necessary a exfat_inode_info's member.
> 
> Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
> ---
>  fs/exfat/dir.c      | 16 ++++++----------
>  fs/exfat/exfat_fs.h |  2 --
>  fs/exfat/file.c     |  2 --
>  fs/exfat/inode.c    |  3 ---
>  fs/exfat/super.c    |  1 -
>  5 files changed, 6 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> a9b13ae3f325..fa5bb72aa295 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
[snip]
> sector @@ -262,13 +260,11 @@ static int exfat_iterate(struct file *filp,
> struct dir_context *ctx)
>  		goto end_of_dir;
>  	}
> 
> -	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
> -
>  	if (!nb->lfn[0])
>  		goto end_of_dir;
> 
>  	i_pos = ((loff_t)ei->start_clu << 32) |
> -		((ei->rwoffset - 1) & 0xffffffff);
> +		(EXFAT_B_TO_DEN(cpos-1) & 0xffffffff);

Need to fix the above line to be:
(EXFAT_B_TO_DEN(cpos)-1)) & 0xffffffff);

Re: [PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[Tetsuhiro Kohada]

On 2020/09/12 14:01, Sungjong Seo wrote:
>> Remove 'rwoffset' in exfat_inode_info and replace it with the
>> parameter(cpos) of exfat_readdir.
>> Since rwoffset of  is referenced only by exfat_readdir, it is not
>> necessary a exfat_inode_info's member.
>>
>> Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
>> ---
>>   fs/exfat/dir.c      | 16 ++++++----------
>>   fs/exfat/exfat_fs.h |  2 --
>>   fs/exfat/file.c     |  2 --
>>   fs/exfat/inode.c    |  3 ---
>>   fs/exfat/super.c    |  1 -
>>   5 files changed, 6 insertions(+), 18 deletions(-)
>>
>> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
>> a9b13ae3f325..fa5bb72aa295 100644
>> --- a/fs/exfat/dir.c
>> +++ b/fs/exfat/dir.c
> [snip]
>> sector @@ -262,13 +260,11 @@ static int exfat_iterate(struct file *filp,
>> struct dir_context *ctx)
>>   		goto end_of_dir;
>>   	}
>>
>> -	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
>> -
>>   	if (!nb->lfn[0])
>>   		goto end_of_dir;
>>
>>   	i_pos = ((loff_t)ei->start_clu << 32) |
>> -		((ei->rwoffset - 1) & 0xffffffff);
>> +		(EXFAT_B_TO_DEN(cpos-1) & 0xffffffff);
> 
> Need to fix the above line to be:
> (EXFAT_B_TO_DEN(cpos)-1)) & 0xffffffff);


Here, we simply converted so that the calculation results would be the same.
But after reading it carefully again, I noticed.
  - Why use the previous entry?
  - Why does cpos point to stream dir-entry in entry-set?

For the former, there is no need to "++dentry" in exfat_readdir().
For the latter, I think cpos should point to the next to current entry-set.

I'll make V2 considering these.
How do you think?

BR
---
Tetsuhiro Kohada <kohada.t2@gmail.com>

RE: [PATCH] exfat: remove 'rwoffset' in exfat_inode_info

[Sungjong Seo]

> On 2020/09/12 14:01, Sungjong Seo wrote:
> >> Remove 'rwoffset' in exfat_inode_info and replace it with the
> >> parameter(cpos) of exfat_readdir.
> >> Since rwoffset of  is referenced only by exfat_readdir, it is not
> >> necessary a exfat_inode_info's member.
> >>
> >> Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
> >> ---
> >>   fs/exfat/dir.c      | 16 ++++++----------
> >>   fs/exfat/exfat_fs.h |  2 --
> >>   fs/exfat/file.c     |  2 --
> >>   fs/exfat/inode.c    |  3 ---
> >>   fs/exfat/super.c    |  1 -
> >>   5 files changed, 6 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> >> a9b13ae3f325..fa5bb72aa295 100644
> >> --- a/fs/exfat/dir.c
> >> +++ b/fs/exfat/dir.c
> > [snip]
> >> sector @@ -262,13 +260,11 @@ static int exfat_iterate(struct file
> >> *filp, struct dir_context *ctx)
> >>   		goto end_of_dir;
> >>   	}
> >>
> >> -	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
> >> -
> >>   	if (!nb->lfn[0])
> >>   		goto end_of_dir;
> >>
> >>   	i_pos = ((loff_t)ei->start_clu << 32) |
> >> -		((ei->rwoffset - 1) & 0xffffffff);
> >> +		(EXFAT_B_TO_DEN(cpos-1) & 0xffffffff);
> >
> > Need to fix the above line to be:
> > (EXFAT_B_TO_DEN(cpos)-1)) & 0xffffffff);
> 
> 
> Here, we simply converted so that the calculation results would be the
> same.
> But after reading it carefully again, I noticed.
>   - Why use the previous entry?
>   - Why does cpos point to stream dir-entry in entry-set?
> 
> For the former, there is no need to "++dentry" in exfat_readdir().
> For the latter, I think cpos should point to the next to current entry-set.
> 
> I'll make V2 considering these.
> How do you think?

The latter looks better.
> 
> BR
> ---
> Tetsuhiro Kohada <kohada.t2@gmail.com>