From: "Darrick J. Wong" <djwong@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: sandeen@sandeen.net, linux-xfs@vger.kernel.org, bfoster@redhat.com
Subject: Re: [PATCH 07/10] xfs_repair: set NEEDSREPAIR when we deliberately corrupt directories
Date: Tue, 9 Feb 2021 10:45:52 -0800 [thread overview]
Message-ID: <20210209184552.GX7193@magnolia> (raw)
In-Reply-To: <20210209091336.GG1718132@infradead.org>
On Tue, Feb 09, 2021 at 09:13:36AM +0000, Christoph Hellwig wrote:
> On Mon, Feb 08, 2021 at 08:10:44PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> >
> > There are a few places in xfs_repair's directory checking code where we
> > deliberately corrupt a directory entry as a sentinel to trigger a
> > correction in later repair phase. In the mean time, the filesystem is
> > inconsistent, so set the needsrepair flag to force a re-run of repair if
> > the system goes down.
>
> I guess this is an improvement over what we have no, but I suspect an
> in-core side band way to notify the later phases would be much better
> than these corrupt sentinel values..
It would be, but we'd still have to track which directory entries are
thee ones that we don't want to preserve. We could rewrite the
directory entry to point to a plausible inode number that isn't
allocated, but that runs the risk that someone will come along and
allocate that inode for lost+found and then we're really in a mess.
Alternately, I suppose we could rewrite the directory entry to be a
DHT_WHITEOUT entry that doesn't look like any that the kernel would
produce ... insofar as I'm not even sure what the real ones were
supposed to look like, given the weird left turn that overlayfs took on
that. :(
--D
next prev parent reply other threads:[~2021-02-09 19:12 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 4:10 [PATCHSET v4 00/10] xfs: add the ability to flag a fs for repair Darrick J. Wong
2021-02-09 4:10 ` [PATCH 01/10] xfs_admin: clean up string quoting Darrick J. Wong
2021-02-09 9:07 ` Christoph Hellwig
2021-02-09 4:10 ` [PATCH 02/10] xfs_admin: support filesystems with realtime devices Darrick J. Wong
2021-02-09 9:08 ` Christoph Hellwig
2021-02-09 17:19 ` Brian Foster
2021-02-09 4:10 ` [PATCH 03/10] xfs_db: support the needsrepair feature flag in the version command Darrick J. Wong
2021-02-09 9:09 ` Christoph Hellwig
2021-02-09 17:15 ` Darrick J. Wong
2021-02-09 17:19 ` Brian Foster
2021-02-09 4:10 ` [PATCH 04/10] xfs_repair: fix unmount error message to have a newline Darrick J. Wong
2021-02-09 9:09 ` Christoph Hellwig
2021-02-09 4:10 ` [PATCH 05/10] xfs_repair: clear quota CHKD flags on the incore superblock too Darrick J. Wong
2021-02-09 9:10 ` Christoph Hellwig
2021-02-09 17:20 ` Brian Foster
2021-02-09 17:46 ` Darrick J. Wong
2021-02-09 4:10 ` [PATCH 06/10] xfs_repair: clear the needsrepair flag Darrick J. Wong
2021-02-09 9:12 ` Christoph Hellwig
2021-02-09 17:20 ` Brian Foster
2021-02-09 18:01 ` Darrick J. Wong
2021-02-09 4:10 ` [PATCH 07/10] xfs_repair: set NEEDSREPAIR when we deliberately corrupt directories Darrick J. Wong
2021-02-09 9:13 ` Christoph Hellwig
2021-02-09 18:45 ` Darrick J. Wong [this message]
2021-02-09 17:20 ` Brian Foster
2021-02-09 18:35 ` Darrick J. Wong
2021-02-09 19:14 ` Brian Foster
2021-02-09 19:43 ` Darrick J. Wong
2021-02-10 20:19 ` Eric Sandeen
2021-02-09 4:10 ` [PATCH 08/10] xfs_repair: allow setting the needsrepair flag Darrick J. Wong
2021-02-09 9:15 ` Christoph Hellwig
2021-02-09 14:41 ` Eric Sandeen
2021-02-09 16:47 ` Darrick J. Wong
2021-02-10 20:44 ` Eric Sandeen
2021-02-09 17:21 ` Brian Foster
2021-02-09 18:10 ` Darrick J. Wong
2021-02-10 20:26 ` Eric Sandeen
2021-02-09 4:10 ` [PATCH 09/10] xfs_repair: add a testing hook for NEEDSREPAIR Darrick J. Wong
2021-02-09 9:16 ` Christoph Hellwig
2021-02-09 17:21 ` Brian Foster
2021-02-09 18:17 ` Darrick J. Wong
2021-02-09 18:59 ` Brian Foster
2021-02-09 19:59 ` Darrick J. Wong
2021-02-09 20:32 ` Brian Foster
2021-02-10 21:41 ` Eric Sandeen
2021-02-11 1:30 ` Darrick J. Wong
2021-02-09 4:11 ` [PATCH 10/10] xfs_admin: support adding features to V5 filesystems Darrick J. Wong
2021-02-09 9:18 ` Christoph Hellwig
2021-02-09 17:22 ` Brian Foster
2021-02-09 18:22 ` Darrick J. Wong
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=20210209184552.GX7193@magnolia \
--to=djwong@kernel.org \
--cc=bfoster@redhat.com \
--cc=hch@infradead.org \
--cc=linux-xfs@vger.kernel.org \
--cc=sandeen@sandeen.net \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox