From: "Darrick J. Wong" <djwong@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: hch@lst.de, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 1/1] xfs: online repair of symbolic links
Date: Fri, 29 Mar 2024 13:44:51 -0700 [thread overview]
Message-ID: <20240329204451.GO6390@frogsfrogsfrogs> (raw)
In-Reply-To: <ZgRPEk9MdwbPK64Y@infradead.org>
On Wed, Mar 27, 2024 at 09:53:38AM -0700, Christoph Hellwig wrote:
> > /* Write the symlink target into the inode. */
> > int
> > -xfs_symlink_write_target(
> > +__xfs_symlink_write_target(
> > struct xfs_trans *tp,
> > struct xfs_inode *ip,
> > + xfs_ino_t owner,
>
> The xfs_symlink_write_target/__xfs_symlink_write_target split seems
> a bit pointless with just a single real caller for either variant.
> Why not just pass the owner to xfs_symlink_write_target and do away
> with __xfs_symlink_write_target?
>
> > +/*
> > + * Symbolic Link Repair
> > + * ====================
> > + *
> > + * We repair symbolic links by reading whatever target data we can find, up to
> > + * the first NULL byte. Zero length symlinks are turned into links to the
> > + * current directory.
>
> Are we actually doing that? xrep_setup_symlink sets up a link with
> the "." target (and could use a comment on why), but we're always
> writing the long dummy target below now, or am I missing something?
If the target that we salvage has the same strlen as i_size, then we'll
rewrite what we found into the symlink. In all other cases, yes, we
write out the DUMMY_TARGET string.
IOWs, the comment is out of date. Here's what I have now:
/*
* Symbolic Link Repair
* ====================
*
* We repair symbolic links by reading whatever target data we can find, up to
* the first NULL byte. If the recovered target strlen matches i_size, then
* we rewrite the target. In all other cases, we replace the target with an
* overly long string that cannot possibly resolve. The new target is written
* into a private hidden temporary file, and then a file contents exchange
* commits the new symlink target to the file being repaired.
*/
> > +/* Set us up to repair the rtsummary file. */
>
> I don't think that's what it does :)
>
> > + * We cannot use xfs_exchmaps_estimate because we have not yet
> > + * constructed the replacement rtsummary and therefore do not know how
> > + * many extents it will use. By the time we do, we will have a dirty
> > + * transaction (which we cannot drop because we cannot drop the
> > + * rtsummary ILOCK) and cannot ask for more reservation.
>
> No rtsummary here either..
Oops. Fixed both of those things. :(
> > +
> > +#define DUMMY_TARGET \
> > + "The target of this symbolic link could not be recovered at all and " \
> > + "has been replaced with this explanatory message. To avoid " \
> > + "accidentally pointing to an existing file path, this message is " \
> > + "longer than the maximum supported file name length. That is an " \
> > + "acceptable length for a symlink target on XFS but will produce " \
> > + "File Name Too Long errors if resolved."
>
> Haha. Can this cause the repair to run into ENOSPC if the previous
> corrupted symlink was way shorter?
Yes. In that case, xrep_symlink_rebuild will fail to write DUMMY_TARGET
into sc->tempip, we ifree the tempfile (with its '.' target), and return
the error to userspace.
--D
next prev parent reply other threads:[~2024-03-29 20:44 UTC|newest]
Thread overview: 158+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-27 1:40 [PATCHBOMB v30] xfs: online fsck patches for 6.10 Darrick J. Wong
2024-03-27 1:46 ` [PATCHSET 01/15] xfs: bug fixes for 6.9 Darrick J. Wong
2024-03-27 1:50 ` [PATCH 1/1] xfs: fix potential AGI <-> ILOCK ABBA deadlock in xrep_dinode_findmode_walk_directory Darrick J. Wong
2024-03-27 16:56 ` Christoph Hellwig
2024-03-29 18:38 ` Darrick J. Wong
2024-04-03 5:18 ` [PATCHSET] xfs: bug fixes for 6.9 Darrick J. Wong
2024-04-03 5:18 ` [PATCH 1/3] xfs: pass xfs_buf lookup flags to xfs_*read_agi Darrick J. Wong
2024-04-05 14:53 ` Christoph Hellwig
2024-04-03 5:18 ` [PATCH 2/3] xfs: fix an AGI lock acquisition ordering problem in xrep_dinode_findmode Darrick J. Wong
2024-04-05 14:54 ` Christoph Hellwig
2024-04-05 16:52 ` Christoph Hellwig
2024-04-07 22:34 ` Dave Chinner
2024-04-09 22:51 ` Darrick J. Wong
2024-04-03 5:18 ` [PATCH 3/3] xfs: fix potential AGI <-> ILOCK ABBA deadlock in xrep_dinode_findmode_walk_directory Darrick J. Wong
2024-04-05 3:27 ` [PATCH 4/3] xfs: fix error bailout in xrep_abt_build_new_trees Darrick J. Wong
2024-04-05 5:17 ` Christoph Hellwig
2024-03-27 1:46 ` [PATCHSET v30.1 02/15] xfs: improve log incompat feature handling Darrick J. Wong
2024-03-27 1:50 ` [PATCH 1/2] xfs: only clear log incompat flags at clean unmount Darrick J. Wong
2024-04-07 22:48 ` Dave Chinner
2024-03-27 1:51 ` [PATCH 2/2] xfs: only add log incompat features with explicit permission Darrick J. Wong
2024-04-07 23:00 ` Dave Chinner
2024-04-09 22:53 ` Darrick J. Wong
2024-03-27 1:47 ` [PATCHSET v30.1 03/15] xfs: refactorings for atomic file content exchanges Darrick J. Wong
2024-03-27 1:51 ` [PATCH 1/7] xfs: move inode lease breaking functions to xfs_inode.c Darrick J. Wong
2024-03-27 1:51 ` [PATCH 2/7] xfs: move xfs_iops.c declarations out of xfs_inode.h Darrick J. Wong
2024-03-27 1:51 ` [PATCH 3/7] xfs: declare xfs_file.c symbols in xfs_file.h Darrick J. Wong
2024-03-27 1:52 ` [PATCH 4/7] xfs: create a new helper to return a file's allocation unit Darrick J. Wong
2024-03-27 1:52 ` [PATCH 5/7] xfs: hoist multi-fsb allocation unit detection to a helper Darrick J. Wong
2024-03-27 11:05 ` Christoph Hellwig
2024-04-07 23:07 ` Dave Chinner
2024-04-09 21:09 ` Darrick J. Wong
2024-03-27 1:52 ` [PATCH 6/7] xfs: refactor non-power-of-two alignment checks Darrick J. Wong
2024-03-27 1:52 ` [PATCH 7/7] xfs: constify xfs_bmap_is_written_extent Darrick J. Wong
2024-03-27 1:47 ` [PATCHSET v30.1 04/15] xfs: atomic file content exchanges Darrick J. Wong
2024-03-27 1:53 ` [PATCH 01/15] vfs: export remap and write check helpers Darrick J. Wong
2024-03-27 11:07 ` Christoph Hellwig
2024-03-29 19:45 ` Darrick J. Wong
2024-03-27 1:53 ` [PATCH 02/15] xfs: introduce new file range exchange ioctl Darrick J. Wong
2024-03-27 11:12 ` Christoph Hellwig
2024-03-27 1:53 ` [PATCH 03/15] xfs: create a log incompat flag for atomic file mapping exchanges Darrick J. Wong
2024-04-07 23:17 ` Dave Chinner
2024-04-09 21:12 ` Darrick J. Wong
2024-03-27 1:53 ` [PATCH 04/15] xfs: introduce a file mapping exchange log intent item Darrick J. Wong
2024-04-07 23:51 ` Dave Chinner
2024-04-09 1:18 ` Darrick J. Wong
2024-04-09 3:06 ` Darrick J. Wong
2024-03-27 1:54 ` [PATCH 05/15] xfs: create deferred log items for file mapping exchanges Darrick J. Wong
2024-03-27 1:54 ` [PATCH 06/15] xfs: bind together the front and back ends of the file range exchange code Darrick J. Wong
2024-04-08 0:05 ` Dave Chinner
2024-03-27 1:54 ` [PATCH 07/15] xfs: add error injection to test file mapping exchange recovery Darrick J. Wong
2024-03-27 1:54 ` [PATCH 08/15] xfs: condense extended attributes after a mapping exchange operation Darrick J. Wong
2024-03-27 1:55 ` [PATCH 09/15] xfs: condense directories " Darrick J. Wong
2024-03-27 1:55 ` [PATCH 10/15] xfs: condense symbolic links " Darrick J. Wong
2024-03-27 1:55 ` [PATCH 11/15] xfs: make file range exchange support realtime files Darrick J. Wong
2024-03-27 1:55 ` [PATCH 12/15] xfs: support non-power-of-two rtextsize with exchange-range Darrick J. Wong
2024-03-27 1:56 ` [PATCH 13/15] docs: update swapext -> exchmaps language Darrick J. Wong
2024-03-27 1:56 ` [PATCH 14/15] xfs: introduce new file range commit ioctls Darrick J. Wong
2024-03-27 11:06 ` Christoph Hellwig
2024-03-29 19:45 ` Darrick J. Wong
2024-03-27 1:56 ` [PATCH 15/15] xfs: enable logged file mapping exchange feature Darrick J. Wong
2024-03-27 1:47 ` [PATCHSET v30.1 05/15] xfs: create temporary files for online repair Darrick J. Wong
2024-03-27 1:57 ` [PATCH 1/4] xfs: hide private inodes from bulkstat and handle functions Darrick J. Wong
2024-03-27 11:12 ` Christoph Hellwig
2024-03-27 1:57 ` [PATCH 2/4] xfs: create temporary files and directories for online repair Darrick J. Wong
2024-03-27 1:57 ` [PATCH 3/4] xfs: refactor live buffer invalidation for repairs Darrick J. Wong
2024-03-27 1:57 ` [PATCH 4/4] xfs: add the ability to reap entire inode forks Darrick J. Wong
2024-03-27 1:47 ` [PATCHSET v30.1 06/15] xfs: online repair of realtime summaries Darrick J. Wong
2024-03-27 1:58 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
2024-03-27 1:58 ` [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges Darrick J. Wong
2024-03-27 1:58 ` [PATCH 3/3] xfs: online repair of realtime summaries Darrick J. Wong
2024-03-27 1:48 ` [PATCHSET v30.1 07/15] xfs: set and validate dir/attr block owners Darrick J. Wong
2024-03-27 1:58 ` [PATCH 01/10] xfs: add an explicit owner field to xfs_da_args Darrick J. Wong
2024-03-27 1:59 ` [PATCH 02/10] xfs: use the xfs_da_args owner field to set new dir/attr block owner Darrick J. Wong
2024-03-27 1:59 ` [PATCH 03/10] xfs: reduce indenting in xfs_attr_node_list Darrick J. Wong
2024-03-27 11:13 ` Christoph Hellwig
2024-03-28 17:39 ` Darrick J. Wong
2024-03-27 1:59 ` [PATCH 04/10] xfs: validate attr leaf buffer owners Darrick J. Wong
2024-03-27 1:59 ` [PATCH 05/10] xfs: validate attr remote value " Darrick J. Wong
2024-03-27 2:00 ` [PATCH 06/10] xfs: validate dabtree node " Darrick J. Wong
2024-03-27 2:00 ` [PATCH 07/10] xfs: validate directory leaf " Darrick J. Wong
2024-03-27 2:00 ` [PATCH 08/10] xfs: validate explicit directory data " Darrick J. Wong
2024-03-27 2:00 ` [PATCH 09/10] xfs: validate explicit directory block " Darrick J. Wong
2024-03-27 2:01 ` [PATCH 10/10] xfs: validate explicit directory free block owners Darrick J. Wong
2024-03-27 1:48 ` [PATCHSET v30.1 08/15] xfs: online repair of extended attributes Darrick J. Wong
2024-03-27 2:01 ` [PATCH 1/7] xfs: enable discarding of folios backing an xfile Darrick J. Wong
2024-03-27 2:01 ` [PATCH 2/7] xfs: create a blob array data structure Darrick J. Wong
2024-03-27 2:01 ` [PATCH 3/7] xfs: use atomic extent swapping to fix user file fork data Darrick J. Wong
2024-03-27 2:02 ` [PATCH 4/7] xfs: repair extended attributes Darrick J. Wong
2024-03-27 2:02 ` [PATCH 5/7] xfs: scrub should set preen if attr leaf has holes Darrick J. Wong
2024-03-27 2:02 ` [PATCH 6/7] xfs: flag empty xattr leaf blocks for optimization Darrick J. Wong
2024-03-27 2:03 ` [PATCH 7/7] xfs: create an xattr iteration function for scrub Darrick J. Wong
2024-03-27 11:15 ` Christoph Hellwig
2024-03-27 1:48 ` [PATCHSET v30.1 09/15] xfs: online repair of inode unlinked state Darrick J. Wong
2024-03-27 2:03 ` [PATCH 1/2] xfs: ensure unlinked list state is consistent with nlink during scrub Darrick J. Wong
2024-03-27 2:03 ` [PATCH 2/2] xfs: update the unlinked list when repairing link counts Darrick J. Wong
2024-03-27 1:48 ` [PATCHSET v30.1 10/15] xfs: online repair of directories Darrick J. Wong
2024-03-27 2:03 ` [PATCH 1/5] xfs: inactivate directory data blocks Darrick J. Wong
2024-03-27 2:04 ` [PATCH 2/5] xfs: online repair of directories Darrick J. Wong
2024-03-27 2:04 ` [PATCH 3/5] xfs: scan the filesystem to repair a directory dotdot entry Darrick J. Wong
2024-03-27 2:04 ` [PATCH 4/5] xfs: online repair of parent pointers Darrick J. Wong
2024-03-27 2:04 ` [PATCH 5/5] xfs: ask the dentry cache if it knows the parent of a directory Darrick J. Wong
2024-03-27 11:16 ` Christoph Hellwig
2024-03-29 19:52 ` Darrick J. Wong
2024-04-03 5:03 ` [PATCH v30.2 " Darrick J. Wong
2024-04-03 11:43 ` Christoph Hellwig
2024-03-27 1:49 ` [PATCHSET v30.1 11/15] xfs: move orphan files to lost and found Darrick J. Wong
2024-03-27 2:05 ` [PATCH 1/3] xfs: move orphan files to the orphanage Darrick J. Wong
2024-03-27 2:05 ` [PATCH 2/3] xfs: move files to orphanage instead of letting nlinks drop to zero Darrick J. Wong
2024-03-27 2:05 ` [PATCH 3/3] xfs: ensure dentry consistency when the orphanage adopts a file Darrick J. Wong
2024-03-27 1:49 ` [PATCHSET v30.1 12/15] xfs: online repair of symbolic links Darrick J. Wong
2024-03-27 2:05 ` [PATCH 1/1] " Darrick J. Wong
2024-03-27 16:53 ` Christoph Hellwig
2024-03-29 20:44 ` Darrick J. Wong [this message]
2024-03-29 20:58 ` Darrick J. Wong
2024-04-03 5:12 ` [PATCHSET v30.2] " Darrick J. Wong
2024-04-03 5:12 ` [PATCH 1/3] xfs: expose xfs_bmap_local_to_extents for online repair Darrick J. Wong
2024-04-03 11:43 ` Christoph Hellwig
2024-04-03 5:12 ` [PATCH 2/3] xfs: pass the owner to xfs_symlink_write_target Darrick J. Wong
2024-04-03 11:43 ` Christoph Hellwig
2024-04-03 5:12 ` [PATCH 3/3] xfs: online repair of symbolic links Darrick J. Wong
2024-04-03 11:44 ` Christoph Hellwig
2024-03-27 1:49 ` [PATCHSET v30.1 13/15] xfs: online fsck of iunlink buckets Darrick J. Wong
2024-03-27 2:06 ` [PATCH 1/3] xfs: check AGI unlinked inode buckets Darrick J. Wong
2024-03-27 2:06 ` [PATCH 2/3] xfs: hoist AGI repair context to a heap object Darrick J. Wong
2024-03-27 2:06 ` [PATCH 3/3] xfs: repair AGI unlinked inode bucket lists Darrick J. Wong
2024-03-27 1:49 ` [PATCHSET v30.1 14/15] xfs: inode-related repair fixes Darrick J. Wong
2024-03-27 2:06 ` [PATCH 1/4] xfs: check unused nlink fields in the ondisk inode Darrick J. Wong
2024-03-27 2:07 ` [PATCH 2/4] xfs: try to avoid allocating from sick inode clusters Darrick J. Wong
2024-03-27 2:07 ` [PATCH 3/4] xfs: pin inodes that would otherwise overflow link count Darrick J. Wong
2024-03-27 2:07 ` [PATCH 4/4] xfs: create subordinate scrub contexts for xchk_metadata_inode_subtype Darrick J. Wong
2024-03-27 1:50 ` [PATCHSET v30.1 15/15] xfs: less heavy locks during fstrim Darrick J. Wong
2024-03-27 2:07 ` [PATCH 1/1] xfs: fix severe performance problems when fstrimming a subset of an AG Darrick J. Wong
2024-03-27 11:35 ` Christoph Hellwig
2024-03-29 21:35 ` Darrick J. Wong
2024-03-30 5:38 ` Christoph Hellwig
2024-03-30 21:15 ` Dave Chinner
2024-03-31 22:44 ` Darrick J. Wong
2024-03-27 22:15 ` Dave Chinner
2024-03-29 22:51 ` Darrick J. Wong
2024-03-30 21:51 ` Dave Chinner
2024-03-31 22:44 ` Darrick J. Wong
2024-04-01 22:12 ` Dave Chinner
2024-04-03 5:07 ` [PATCH v30.2 " Darrick J. Wong
2024-04-04 21:46 ` Dave Chinner
-- strict thread matches above, loose matches on Subject: below --
2024-02-27 2:18 [PATCHSET v29.['hch@lst.de'] 11/13] xfs: online repair of symbolic links Darrick J. Wong
2024-02-27 2:32 ` [PATCH 1/1] " Darrick J. Wong
2024-02-28 17:26 ` Christoph Hellwig
2024-02-28 18:37 ` Darrick J. Wong
2024-02-28 18:53 ` Christoph Hellwig
2024-02-28 20:52 ` Darrick J. Wong
2024-02-28 22:10 ` Christoph Hellwig
2024-02-28 23:46 ` Darrick J. Wong
2024-02-29 13:25 ` Christoph Hellwig
2024-02-29 17:16 ` Darrick J. Wong
2024-02-29 19:42 ` Christoph Hellwig
2023-12-31 19:45 [PATCHSET v29.0 23/40] xfsprogs: " Darrick J. Wong
2023-12-31 22:35 ` [PATCH 1/1] xfs: " Darrick J. Wong
2023-12-31 19:31 [PATCHSET v29.0 24/28] " Darrick J. Wong
2023-12-31 20:39 ` [PATCH 1/1] " Darrick J. Wong
2023-05-26 0:36 [PATCHSET v25.0 0/1] " Darrick J. Wong
2023-05-26 1:36 ` [PATCH 1/1] " Darrick J. Wong
2022-12-30 22:14 [PATCHSET v24.0 0/1] " Darrick J. Wong
2022-12-30 22:14 ` [PATCH 1/1] " Darrick J. Wong
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