Add a helper to switch between the different directory formats for
removing a directory entry.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Add a helper to switch between the different directory formats for
removing a directory entry.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Add a helper to switch between the different directory formats for
creating a directory entry and to handle the XFS_DA_OP_JUSTCHECK flag
based on the passed in ino number field.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Add a helper to switch between the different directory formats for
lookup and to handle the -EEXIST return for a successful lookup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs: minor fixes to online repair
Here are some miscellaneous bug fixes for the online repair code.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'repair-fixes-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: invalidate dentries for a file before moving it to the orphanage
xfs: exchange-range for repairs is no longer dynamic
xfs: fix iunlock calls in xrep_adoption_trans_alloc
xfs: drop the scrub file's iolock when transaction allocation fails
xfs: reduce iget overhead in scrub
This patchset looks to reduce iget overhead in two ways: First, a
previous patch conditionally set DONTCACHE on inodes during xchk_irele
on the grounds that we knew better at irele time if an inode should be
dropped. Unfortunately, over time that patch morphed into a call to
d_mark_dontcache, which resulted in inodes being dropped even if they
were referenced by the dcache. This actually caused *more* recycle
overhead than if we'd simply called xfs_iget to set DONTCACHE only on
misses.
The second patch reduces the cost of untrusted iget for a vectored scrub
call by having the scrubv code maintain a separate refcount to the inode
so that the cache will always hit.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'reduce-scrub-iget-overhead-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: only iget the file once when doing vectored scrub-by-handle
xfs: use dontcache for grabbing inodes during scrub
xfs: vectorize scrub kernel calls
Create a vectorized version of the metadata scrub and repair ioctl, and
adapt xfs_scrub to use that. This mitigates the impact of system call
overhead on xfs_scrub runtime.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'vectorized-scrub-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: introduce vectored scrub mode
xfs: move xfs_ioc_scrub_metadata to scrub.c
xfs: reduce the rate of cond_resched calls inside scrub
xfs: detect and correct directory tree problems
Historically, checking the tree-ness of the directory tree structure has
not been complete. Cycles of subdirectories break the tree properties,
as do subdirectories with multiple parents. It's easy enough for DFS to
detect problems as long as one of the participants is reachable from the
root, but this technique cannot find unconnected cycles.
Directory parent pointers change that, because we can discover all of
these problems from a simple walk from a subdirectory towards the root.
For each child we start with, if the walk terminates without reaching
the root, we know the path is disconnected and ought to be attached to
the lost and found. If we find ourselves, we know this is a cycle and
can delete an incoming edge. If we find multiple paths to the root, we
know to delete an incoming edge.
Even better, once we've finished walking paths, we've identified the
good ones and know which other path(s) to remove.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'scrub-directory-tree-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: fix corruptions in the directory tree
xfs: report directory tree corruption in the health information
xfs: invalidate dirloop scrub path data when concurrent updates happen
xfs: teach online scrub to find directory tree structure problems
xfs: online repair for parent pointers
This series implements online repair for directory parent pointer
metadata. The checking half is fairly straightforward -- for each
outgoing directory link (forward or backwards), grab the inode at the
other end, and confirm that there's a corresponding link. If we can't
grab an inode or lock it, we'll save that link for a slower loop that
cycles all the locks, confirms the continued existence of the link, and
rechecks the link if it's actually still there.
Repairs are a bit more involved -- for directories, we walk the entire
filesystem to rebuild the dirents from parent pointer information.
Parent pointer repairs do the same walk but rebuild the pptrs from the
dirent information, but with the added twist that it duplicates all the
xattrs so that it can use the atomic extent swapping code to commit the
repairs atomically.
This introduces an added twist to the xattr repair code -- we use dirent
hooks to detect a colliding update to the pptr data while we're not
holding the ILOCKs; if one is detected, we restart the xattr salvaging
process but this time hold all the ILOCKs until the end of the scan.
For offline repair, the phase6 directory connectivity scan generates an
index of all the expected parent pointers in the filesystem. Then it
walks each file and compares the parent pointers attached to that file
against the index generated, and resyncs the results as necessary.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'repair-pptrs-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: inode repair should ensure there's an attr fork to store parent pointers
xfs: repair link count of nondirectories after rebuilding parent pointers
xfs: adapt the orphanage code to handle parent pointers
xfs: actually rebuild the parent pointer xattrs
xfs: add a per-leaf block callback to xchk_xattr_walk
xfs: split xfs_bmap_add_attrfork into two pieces
xfs: remove pointless unlocked assertion
xfs: implement live updates for parent pointer repairs
xfs: repair directory parent pointers by scanning for dirents
xfs: replay unlocked parent pointer updates that accrue during xattr repair
xfs: implement live updates for directory repairs
xfs: repair directories by scanning directory parent pointers
xfs: add raw parent pointer apis to support repair
xfs: salvage parent pointers when rebuilding xattr structures
xfs: make the reserved block permission flag explicit in xfs_attr_set
xfs: remove some boilerplate from xfs_attr_set
xfs: scrubbing for parent pointers
Teach online fsck to use parent pointers to assist in checking
directories, parent pointers, extended attributes, and link counts.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'scrub-pptrs-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: check parent pointer xattrs when scrubbing
xfs: walk directory parent pointers to determine backref count
xfs: deferred scrub of parent pointers
xfs: scrub parent pointers
xfs: deferred scrub of dirents
xfs: check dirents have parent pointers
xfs: revert commit 44af6c7e59
xfs: Parent Pointers
This is the latest parent pointer attributes for xfs. The goal of this
patch set is to add a parent pointer attribute to each inode. The
attribute name containing the parent inode, generation, and directory
offset, while the attribute value contains the file name. This feature
will enable future optimizations for online scrub, shrink, nfs handles,
verity, or any other feature that could make use of quickly deriving an
inodes path from the mount point.
Directory parent pointers are stored as namespaced extended attributes
of a file. Because parent pointers are an indivisible tuple of
(dirent_name, parent_ino, parent_gen) we cannot use the usual attr name
lookup functions to find a parent pointer. This is solvable by
introducing a new lookup mode that checks both the name and the value of
the xattr.
Therefore, introduce this new name-value lookup mode that's gated on the
XFS_ATTR_PARENT namespace. This requires the introduction of new
opcodes for the extended attribute update log intent items, which
actually means that parent pointers (itself an INCOMPAT feature) does
not depend on the LOGGED_XATTRS log incompat feature bit.
To reduce collisions on the dirent names of parent pointers, introduce a
new attr hash mode that is the dir2 namehash of the dirent name xor'd
with the parent inode number.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'pptrs-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: enable parent pointers
xfs: drop compatibility minimum log size computations for reflink
xfs: fix unit conversion error in xfs_log_calc_max_attrsetm_res
xfs: add a incompat feature bit for parent pointers
xfs: don't remove the attr fork when parent pointers are enabled
xfs: add parent pointer ioctls
xfs: split out handle management helpers a bit
xfs: move handle ioctl code to xfs_handle.c
xfs: pass the attr value to put_listent when possible
xfs: don't return XFS_ATTR_PARENT attributes via listxattr
xfs: Add parent pointers to xfs_cross_rename
xfs: Add parent pointers to rename
xfs: remove parent pointers in unlink
xfs: add parent attributes to symlink
xfs: add parent attributes to link
xfs: parent pointer attribute creation
xfs: create a hashname function for parent pointers
xfs: extend transaction reservations for parent attributes
xfs: add parent pointer validator functions
xfs: Expose init_xattrs in xfs_create_tmpfile
xfs: record inode generation in xattr update log intent items
xfs: create attr log item opcodes and formats for parent pointers
xfs: refactor xfs_is_using_logged_xattrs checks in attr item recovery
xfs: allow xattr matching on name and value for parent pointers
xfs: define parent pointer ondisk extended attribute format
xfs: add parent pointer support to attribute code
xfs: create a separate hashname function for extended attributes
xfs: move xfs_attr_defer_add to xfs_attr_item.c
xfs: check the flags earlier in xfs_attr_match
xfs: rearrange xfs_attr_match parameters
xfs: improve extended attribute validation
Prior to introducing parent pointer extended attributes, let's spend
some time cleaning up the attr code and strengthening the validation
that it performs on attrs coming in from the disk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'improve-attr-validation-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: enforce one namespace per attribute
xfs: refactor name/value iovec validation in xlog_recover_attri_commit_pass2
xfs: refactor name/length checks in xfs_attri_validate
xfs: use local variables for name and value length in _attri_commit_pass2
xfs: always set args->value in xfs_attri_item_recover
xfs: validate recovered name buffers when recovering xattr items
xfs: use helpers to extract xattr op from opflags
xfs: restructure xfs_attr_complete_op a bit
xfs: check shortform attr entry flags specifically
xfs: fix missing check for invalid attr flags
xfs: check opcode and iovec count match in xlog_recover_attri_commit_pass2
xfs: use an XFS_OPSTATE_ flag for detecting if logged xattrs are available
xfs: require XFS_SB_FEAT_INCOMPAT_LOG_XATTRS for attr log intent item recovery
xfs: attr fork iext must be loaded before calling xfs_attr_is_leaf
xfs: shrink struct xfs_da_args
Let's clean out some unused flags and fields from struct xfs_da_args.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* tag 'shrink-dirattr-args-6.10_2024-04-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
xfs: rearrange xfs_da_args a bit to use less space
xfs: make attr removal an explicit operation
xfs: remove xfs_da_args.attr_flags
xfs: remove XFS_DA_OP_NOTIME
xfs: remove XFS_DA_OP_REMOVE
Invalidate the cached dentries that point to the file that we're moving
to lost+found before we actually move it.
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>
If the transaction allocation in xrep_adoption_trans_alloc fails, we
should drop only the locks that we took. In this case this is
ILOCK_EXCL of both the orphanage and the file being repaired. Dropping
any IOLOCK here is incorrect.
Found by fuzzing u3.sfdir3.list[1].name = zeroes in xfs/1546.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If a program wants us to perform a scrub on a file handle and the fd
passed to ioctl() is not the file referenced in the handle, iget the
file once and pass it into the scrub code. This amortizes the untrusted
iget lookup over /all/ the scrubbers mentioned in the scrubv call.
When running fstests in "rebuild all metadata after each test" mode, I
observed a 10% reduction in runtime on account of avoiding repeated
inobt lookups.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Introduce a variant on XFS_SCRUB_METADATA that allows for a vectored
mode. The caller specifies the principal metadata object that they want
to scrub (allocation group, inode, etc.) once, followed by an array of
scrub types they want called on that object. The kernel runs the scrub
operations and writes the output flags and errno code to the
corresponding array element.
A new pseudo scrub type BARRIER is introduced to force the kernel to
return to userspace if any corruptions have been found when scrubbing
the previous scrub types in the array. This enables userspace to
schedule, for example, the sequence:
1. data fork
2. barrier
3. directory
If the data fork scrub is clean, then the kernel will perform the
directory scrub. If not, the barrier in 2 will exit back to userspace.
The alternative would have been an interface where userspace passes a
pointer to an empty buffer, and the kernel formats that with
xfs_scrub_vecs that tell userspace what it scrubbed and what the outcome
was. With that the kernel would have to communicate that the buffer
needed to have been at least X size, even though for our cases
XFS_SCRUB_TYPE_NR + 2 would always be enough.
Compared to that, this design keeps all the dependency policy and
ordering logic in userspace where it already resides instead of
duplicating it in the kernel. The downside of that is that it needs the
barrier logic.
When running fstests in "rebuild all metadata after each test" mode, I
observed a 10% reduction in runtime due to fewer transitions across the
system call boundary.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the transaction allocation in the !orphanage_available case of
xrep_nlinks_repair_inode fails, we need to drop the IOLOCK of the file
being scrubbed before exiting.
Found by fuzzing u3.sfdir3.list[1].name = zeroes in xfs/1546.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Back when I wrote commit a03297a0ca, I had thought that we'd be doing
users a favor by only marking inodes dontcache at the end of a scrub
operation, and only if there's only one reference to that inode. This
was more or less true back when I_DONTCACHE was an XFS iflag and the
only thing it did was change the outcome of xfs_fs_drop_inode to 1.
Note: If there are dentries pointing to the inode when scrub finishes,
the inode will have positive i_count and stay around in cache until
dentry reclaim.
But now we have d_mark_dontcache, which cause the inode *and* the
dentries attached to it all to be marked I_DONTCACHE, which means that
we drop the dentries ASAP, which drops the inode ASAP.
This is bad if scrub found problems with the inode, because now they can
be scheduled for inactivation, which can cause inodegc to trip on it and
shut down the filesystem.
Even if the inode isn't bad, this is still suboptimal because phases 3-7
each initiate inode scans. Dropping the inode immediately during phase
3 is silly because phase 5 will reload it and drop it immediately, etc.
It's fine to mark the inodes dontcache, but if there have been accesses
to the file that set up dentries, we should keep them.
I validated this by setting up ftrace to capture xfs_iget_recycle*
tracepoints and ran xfs/285 for 30 seconds. With current djwong-wtf I
saw ~30,000 recycle events. I then dropped the d_mark_dontcache calls
and set XFS_IGET_DONTCACHE, and the recycle events dropped to ~5,000 per
30 seconds.
Therefore, grab the inode with XFS_IGET_DONTCACHE, which only has the
effect of setting I_DONTCACHE for cache misses. Remove the
d_mark_dontcache call that can happen in xchk_irele.
Fixes: a03297a0ca ("xfs: manage inode DONTCACHE status at irele time")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair corruptions in the directory tree itself. Cycles are broken by
removing an incoming parent->child link. Multiply-owned directories are
fixed by pruning the extra parent -> child links Disconnected subtrees
are reconnected to the lost and found.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Move the scrub ioctl handler to scrub.c to keep the code together and to
reduce unnecessary code when CONFIG_XFS_ONLINE_SCRUB=n.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Report directories that are the source of corruption in the directory
tree.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We really don't want to call cond_resched every single time we go
through a loop in scrub -- there may be billions of records, and probing
into the scheduler itself has overhead. Reduce this overhead by only
calling cond_resched 10x per second; and add a counter so that we only
check jiffies once every 1000 records or so.
Surprisingly, this reduces scrub-only fstests runtime by about 2%. I
used the bmapinflate xfs_db command to produce a billion-extent file and
this stupid gadget reduced the scrub runtime by about 4%.
From a stupid microbenchmark of calling these things 1 billion times, I
estimate that cond_resched costs about 5.5ns per call; jiffes costs
about 0.3ns per read; and fatal_signal_pending costs about 0.4ns per
call.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The runtime parent pointer update code expects that any file being moved
around the directory tree already has an attr fork. However, if we had
to rebuild an inode core record, there's a chance that we zeroed forkoff
as part of the inode to pass the iget verifiers.
Therefore, if we performed any repairs on an inode core, ensure that the
inode has a nonzero forkoff before unlocking the inode.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add a dirent update hook so that we can detect directory tree updates
that affect any of the paths found by this scrubber and force it to
rescan.
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>
Create a new scrubber that detects corruptions within the directory tree
structure itself. It can detect directories with multiple parents;
loops within the directory tree; and directory loops not accessible from
the root.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Adapt the orphanage's adoption code to update the child file's parent
pointers as part of the reparenting process. Also ensure that the child
has an attr fork to receive the parent pointer update, since the runtime
code assumes one exists.
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>
Add a second callback function to xchk_xattr_walk so that we can do
something in between attr leaf blocks. This will be used by the next
patch to see if we should flush cached parent pointer updates to
constrain memory usage.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Split this function into two pieces -- one to make the actual changes to
the inode core to add the attr fork, and another one to deal with
getting the transaction and locking the inodes.
The next couple of patches will need this to be split into two. One
patch implements committing new parent pointer recordsets to damaged
files. If one file has an attr fork and the other does not, we have to
create the missing attr fork before the atomic swap transaction, and can
use the behavior encoded in the current xfs_bmap_add_attrfork.
The second patch adapts /lost+found adoptions to handle parent pointers
correctly. The adoption process will add a parent pointer to a child
that is being moved to /lost+found, but this requires that the attr fork
already exists. We don't know if we're actually going to commit the
adoption until we've already reserved a transaction and taken the
ILOCKs, which means that we must have a way to bypass the start of the
current xfs_bmap_add_attrfork.
Therefore, create xfs_attr_add_fork as the helper that creates a
transaction and takes locks; and make xfs_bmap_add_attrfork the function
that updates the inode core and allocates the incore attr fork.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Remove this assertion about the inode not having an attr fork from
xfs_bmap_add_attrfork because the function handles that case just fine.
Weirder still, the function actually /requires/ the caller not to hold
the ILOCK, which means that its accesses are not stabilized.
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>
There are a few places where the extended attribute repair code drops
the ILOCK to apply stashed xattrs to the temporary file. Although
setxattr and removexattr are still locked out because we retain our hold
on the IOLOCK, this doesn't prevent renames from updating parent
pointers, because the VFS doesn't take i_rwsem on children that are
being moved.
Therefore, set up a dirent hook to capture parent pointer updates for
this file, and replay(?) the updates.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
While we're scanning the filesystem for parent pointers that we can turn
into dirents, we cannot hold the IOLOCK or ILOCK of the directory being
repaired. Therefore, we need to set up a dirent hook so that we can
keep the temporary directory up to date with the rest of the filesystem.
Hence we add the ability to *remove* entries from the temporary dir.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
For filesystems with parent pointers, scan the entire filesystem looking
for parent pointers that target the directory we're rebuilding instead
of trying to salvage whatever we can from the directory data blocks.
This will be more robust than salvaging, but there's more code to come.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Add a couple of utility functions to set or remove parent pointers from
a file. These functions will be used by repair code, hence they skip
the xattr logging that regular parent pointer updates use.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Check parent pointer xattrs as part of scrubbing xattrs.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When we're salvaging extended attributes, make sure we validate the ones
that claim to be parent pointers before adding them to the salvage pile.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the filesystem has parent pointers enabled, walk the parent pointers
of subdirectories to determine the true backref count. In theory each
subdir should have a single parent reachable via dotdot, but in the case
of (corrupt) subdirs with multiple parents, we need to keep the link
counts high enough that the directory loop detector will be able to
correct the multiple parents problems.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Make the use of reserved blocks an explicit parameter to xfs_attr_set.
Userspace setting XFS_ATTR_ROOT attrs should continue to be able to use
it, but for online repairs we can back out and therefore do not care.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In preparation for online/offline repair wanting to use xfs_attr_set,
move some of the boilerplate out of this function into the callers.
Repair can initialize the da_args completely, and the userspace flag
handling/twisting goes away once we move it to xfs_attr_change.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the trylock-based dirent check fails, retain those parent pointers
and check them at the end. This may involve dropping the locks on the
file being scanned, so yay.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the trylock-based parent pointer check fails, retain those dirents
and check them at the end. This may involve dropping the locks on the
file being scanned, so yay.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the fs has parent pointers, we need to check that each child dirent
points to a file that has a parent pointer pointing back at us.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
