xchk_trans_alloc_empty can't return errors, so return the allocated
transaction directly instead of an output double pointer argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Starting with the metadata directory feature, we're allowed to call the
directory and parent pointer scrubbers for every metadata file,
including the ones that are children of the superblock.
For these children, checking the link count against the number of parent
pointers is a bit funny -- there's no such thing as a parent pointer for
a child of the superblock since there's no corresponding dirent. For
purposes of validating nlink, we pretend that there is a parent pointer.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Metadata directory trees make reasoning about the parent of a file more
difficult. Traditionally, user files are children of sb_rootino, and
metadata files are "children" of the superblock. Now, we add a third
possibility -- some metadata files can be children of sb_metadirino, but
the classic ones (rt free space data and quotas) are left alone.
Let's add some helper functions (instead of open-coding the logic
everywhere) to make scrub logic easier to understand.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The atomic file exchange-range functionality is now a permanent
filesystem feature instead of a dynamic log-incompat feature. It cannot
be turned on at runtime, so we no longer need the XCHK_FSGATES flags and
whatnot that supported it. Remove the flag and the enable function, and
move the xfs_has_exchange_range checks to the start of the repair
functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Since the parent pointer scrubber does not exhaustively search the
filesystem for missing parent pointers, it doesn't have a good way to
determine that there are pointers missing from an otherwise uncorrupt
xattr structure. Instead, for nondirectories it employs a heuristic of
comparing the file link count to the number of parent pointers found.
However, we don't want this heuristic flagging a false corruption after
a repair has actually scanned the entire filesystem to rebuild the
parent pointers. Therefore, reset the file link count in this one case
because we actually know the correct link count.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Once we've assembled all the parent pointers for a file, we need to
commit the new dataset atomically to that file. Parent pointer records
are embedded in the xattr structure, which means that we must write a
new extended attribute structure, again, atomically. Therefore, we must
copy the non-parent-pointer attributes from the file being repaired into
the temporary file's extended attributes and then call the atomic extent
swap mechanism to exchange the blocks.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
While we're scanning the filesystem for dirents that we can turn into
parent pointers, we cannot hold the IOLOCK or ILOCK of the file being
repaired. Therefore, we need to set up a dirent hook so that we can
keep the temporary file's parent pionters up to date with the rest of
the filesystem. Hence we add the ability to *remove* pptrs from the
temporary file.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If parent pointers are enabled on the filesystem, we can repair the
entire dataset by walking the directories of the filesystem looking for
dirents that we can turn into parent pointers. Once we have a full
incore dataset, we'll figure out what to do with it, but that's for a
subsequent patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This patch removes the old parent pointer attribute during the rename
operation, and re-adds the updated parent pointer.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: adjust to new ondisk format]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're repairing a directory structure or fixing the dotdot entry of
a subdirectory, it's possible that we won't ever find a parent for the
subdirectory. When this is the case, move it to the orphanage, aka
/lost+found.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
It's possible that the dentry cache can tell us the parent of a
directory. Therefore, when repairing directory dot dot entries, query
the dcache as a last resort before scanning the entire filesystem.
A reviewer asks:
"How high is the chance that we actually have a valid dcache entry for a
file in a corrupted directory?"
There's a decent chance of this actually working. Say you have a
1000-block directory foo, and block 980 gets corrupted. Let's further
suppose that block 0 has a correct entry for ".." and "bar". If someone
accesses /mnt/foo/bar, that will cause the dcache to create a dentry
from /mnt to /mnt/foo whose d_parent points back to /mnt. If you then
want to rebuild the directory, XFS can obtain the parent from the dcache
without needing to wander into parent pointers or scan the filesystem to
find /mnt's connection to foo.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Teach the online repair code to fix parent pointers for directories.
For now, this means correcting the dotdot entry of an existing directory
that is otherwise consistent.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
