From: Christoph Hellwig <hch@lst.de>
To: Eric Sandeen <sandeen@redhat.com>
Cc: xfs <linux-xfs@vger.kernel.org>,
stable@vger.kernel.org, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH STABLE] xfs: trim IO to found COW exent limit
Date: Thu, 24 Sep 2020 06:03:27 +0200 [thread overview]
Message-ID: <20200924040327.GA8078@lst.de> (raw)
In-Reply-To: <e7fe7225-4f2b-d13e-bb4b-c7db68f63124@redhat.com>
On Wed, Sep 23, 2020 at 05:35:44PM -0500, Eric Sandeen wrote:
> A bug existed in the XFS reflink code between v5.1 and v5.5 in which
> the mapping for a COW IO was not trimmed to the mapping of the COW
> extent that was found. This resulted in a too-short copy, and
> corruption of other files which shared the original extent.
>
> (This happened only when extent size hints were set, which bypasses
> delalloc and led to this code path.)
>
> This was (inadvertently) fixed upstream with
>
> 36adcbace24e "xfs: fill out the srcmap in iomap_begin"
>
> and related patches which moved lots of this functionality to
> the iomap subsystem.
>
> Hence, this is a -stable only patch, targeted to fix this
> corruption vector without other major code changes.
>
> Fixes: 78f0cc9d55cb ("xfs: don't use delalloc extents for COW on files with extsize hints")
> Cc: <stable@vger.kernel.org> # 5.4.x
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
and as Darrick said we'll want to wire up the reproducer for xfstests.
prev parent reply other threads:[~2020-09-24 4:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 22:35 [PATCH STABLE] xfs: trim IO to found COW exent limit Eric Sandeen
2020-09-23 22:37 ` Eric Sandeen
2020-09-23 22:59 ` Darrick J. Wong
2020-09-23 23:53 ` Eric Sandeen
2020-09-23 22:58 ` Darrick J. Wong
2020-09-24 4:03 ` Christoph Hellwig [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200924040327.GA8078@lst.de \
--to=hch@lst.de \
--cc=linux-xfs@vger.kernel.org \
--cc=sandeen@redhat.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.