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From: Josef Bacik <josef@toxicpanda.com>
To: Omar Sandoval <osandov@osandov.com>,
	linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
	Al Viro <viro@zeniv.linux.org.uk>,
	Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>, Jann Horn <jannh@google.com>,
	Amir Goldstein <amir73il@gmail.com>,
	Aleksa Sarai <cyphar@cyphar.com>,
	linux-api@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH v5 3/9] fs: add RWF_ENCODED for reading/writing compressed data
Date: Mon, 24 Aug 2020 15:07:13 -0400	[thread overview]
Message-ID: <1ec3bd15-65b3-a258-df4c-bef4f8401b75@toxicpanda.com> (raw)
In-Reply-To: <9020a583581b644ae86b7c05de6a39fd5204f06d.1597993855.git.osandov@osandov.com>

On 8/21/20 3:38 AM, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Btrfs supports transparent compression: data written by the user can be
> compressed when written to disk and decompressed when read back.
> However, we'd like to add an interface to write pre-compressed data
> directly to the filesystem, and the matching interface to read
> compressed data without decompressing it. This adds support for
> so-called "encoded I/O" via preadv2() and pwritev2().
> 
> A new RWF_ENCODED flags indicates that a read or write is "encoded". If
> this flag is set, iov[0].iov_base points to a struct encoded_iov which
> is used for metadata: namely, the compression algorithm, unencoded
> (i.e., decompressed) length, and what subrange of the unencoded data
> should be used (needed for truncated or hole-punched extents and when
> reading in the middle of an extent). For reads, the filesystem returns
> this information; for writes, the caller provides it to the filesystem.
> iov[0].iov_len must be set to sizeof(struct encoded_iov), which can be
> used to extend the interface in the future a la copy_struct_from_user().
> The remaining iovecs contain the encoded extent.
> 
> This adds the VFS helpers for supporting encoded I/O and documentation
> for filesystem support.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

  parent reply	other threads:[~2020-08-24 19:07 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-21  7:38 [PATCH v5 0/9] fs: interface for directly " Omar Sandoval
2020-08-21  7:38 ` [PATCH man-pages v5] Document encoded I/O Omar Sandoval
2020-08-21  9:24   ` Amir Goldstein
2020-08-24 18:15     ` Omar Sandoval
2020-08-21  7:38 ` [PATCH v5 1/9] iov_iter: add copy_struct_from_iter() Omar Sandoval
2020-08-24 18:52   ` Josef Bacik
2020-08-24 21:09     ` Omar Sandoval
2020-08-21  7:38 ` [PATCH v5 2/9] fs: add O_ALLOW_ENCODED open flag Omar Sandoval
2020-08-24 18:28   ` Josef Bacik
2020-08-24 21:11     ` Omar Sandoval
2020-08-21  7:38 ` [PATCH v5 3/9] fs: add RWF_ENCODED for reading/writing compressed data Omar Sandoval
2020-08-21  8:47   ` Amir Goldstein
2020-08-24 23:49     ` Omar Sandoval
2020-08-25  8:25       ` Amir Goldstein
2020-08-25 17:20         ` Omar Sandoval
2020-08-24 19:07   ` Josef Bacik [this message]
2020-08-21  7:38 ` [PATCH v5 4/9] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() Omar Sandoval
2020-08-24 19:17   ` Josef Bacik
2020-08-21  7:38 ` [PATCH v5 5/9] btrfs: add ram_bytes and offset to btrfs_ordered_extent Omar Sandoval
2020-08-24 19:23   ` Josef Bacik
2020-08-21  7:38 ` [PATCH v5 6/9] btrfs: support different disk extent size for delalloc Omar Sandoval
2020-08-24 19:26   ` Josef Bacik
2020-08-21  7:38 ` [PATCH v5 7/9] btrfs: optionally extend i_size in cow_file_range_inline() Omar Sandoval
2020-08-24 19:33   ` Josef Bacik
2020-08-21  7:38 ` [PATCH v5 8/9] btrfs: implement RWF_ENCODED reads Omar Sandoval
2020-08-24 19:54   ` Josef Bacik
2020-08-24 21:23     ` Omar Sandoval
2020-08-21  7:38 ` [PATCH v5 9/9] btrfs: implement RWF_ENCODED writes Omar Sandoval
2020-08-24 20:30   ` Josef Bacik
2020-08-24 21:30     ` Omar Sandoval

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