linux-kernel - Re: [PATCH v4 0/9] xfs/iomap: fix non-atomic clone operation and don't update size when zeroing range post eof

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240417-finster-kichern-31077915c0be@brauner>
Date: Wed, 17 Apr 2024 13:40:36 +0200
From: Christian Brauner <brauner@...nel.org>
To: Chandan Babu R <chandanbabu@...nel.org>
Cc: Zhang Yi <yi.zhang@...weicloud.com>, linux-xfs@...r.kernel.org, 
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, djwong@...nel.org, 
	hch@...radead.org, david@...morbit.com, tytso@....edu, jack@...e.cz, 
	yi.zhang@...wei.com, chengzhihao1@...wei.com, yukuai3@...wei.com
Subject: Re: [PATCH v4 0/9] xfs/iomap: fix non-atomic clone operation and
 don't update size when zeroing range post eof

On Wed, Apr 17, 2024 at 10:12:10AM +0530, Chandan Babu R wrote:
> On Wed, Mar 20, 2024 at 07:05:39 PM +0800, Zhang Yi wrote:
> > Changes since v3:
> >  - Improve some git message comments and do some minor code cleanup, no
> >    logic changes.
> >
> > Changes since v2:
> >  - Merge the patch for dropping of xfs_convert_blocks() and the patch
> >    for modifying xfs_bmapi_convert_delalloc().
> >  - Reword the commit message of the second patch.
> >
> > Changes since v1:
> >  - Make xfs_bmapi_convert_delalloc() to allocate the target offset and
> >    drop the writeback helper xfs_convert_blocks().
> >  - Don't use xfs_iomap_write_direct() to convert delalloc blocks for
> >    zeroing posteof case, use xfs_bmapi_convert_delalloc() instead.
> >  - Fix two off-by-one issues when converting delalloc blocks.
> >  - Add a separate patch to drop the buffered write failure handle in
> >    zeroing and unsharing.
> >  - Add a comments do emphasize updating i_size should under folio lock.
> >  - Make iomap_write_end() to return a boolean, and do some cleanups in
> >    buffered write begin path.
> >
> > This patch series fix a problem of exposing zeroed data on xfs since the
> > non-atomic clone operation. This problem was found while I was
> > developing ext4 buffered IO iomap conversion (ext4 is relying on this
> > fix [1]), the root cause of this problem and the discussion about the
> > solution please see [2]. After fix the problem, iomap_zero_range()
> > doesn't need to update i_size so that ext4 can use it to zero partial
> > block, e.g. truncate eof block [3].
> >
> > [1] https://lore.kernel.org/linux-ext4/20240127015825.1608160-1-yi.zhang@huaweicloud.com/
> > [2] https://lore.kernel.org/linux-ext4/9b0040ef-3d9d-6246-4bdd-82b9a8f55fa2@huaweicloud.com/
> > [3] https://lore.kernel.org/linux-ext4/9c9f1831-a772-299b-072b-1c8116c3fb35@huaweicloud.com/
> >
> > Thanks,
> > Yi.
> >
> > Zhang Yi (9):
> >   xfs: match lock mode in xfs_buffered_write_iomap_begin()
> >   xfs: make the seq argument to xfs_bmapi_convert_delalloc() optional
> >   xfs: make xfs_bmapi_convert_delalloc() to allocate the target offset
> >   xfs: convert delayed extents to unwritten when zeroing post eof blocks
> >   iomap: drop the write failure handles when unsharing and zeroing
> >   iomap: don't increase i_size if it's not a write operation
> >   iomap: use a new variable to handle the written bytes in
> >     iomap_write_iter()
> >   iomap: make iomap_write_end() return a boolean
> >   iomap: do some small logical cleanup in buffered write
> >
> 
> Hi all,
> 
> I have picked up this patchset for inclusion into XFS' 6.10-rc1 patch
> queue. Please let me know if there are any objections.

It'd be nice if I could take the iomap patches into the vfs.iomap tree
that you can then pull from if you depend on it.. There's already some
cleanups in there. Sounds ok?