Commit Graph

754 Commits

Author SHA1 Message Date
Darrick J. Wong
980faece91 xfs: convert "skip_discard" to a proper flags bitset
Convert the boolean to skip discard on free into a proper flags field so
that we can add more flags in the next patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:37:01 -07:00
Darrick J. Wong
62bbf50bea xfs: move dirent update hooks to xfs_dir2.c
Move the directory entry update hook code to xfs_dir2 so that it is
mostly consolidated with the higher level directory functions.  Retain
the exports so that online fsck can still send notifications through the
hooks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:37:00 -07:00
Darrick J. Wong
b11b11e3b7 xfs: separate the icreate logic around INIT_XATTRS
INIT_XATTRS is overloaded here -- it's set during the creat process when
we think that we're immediately going to set some ACL xattrs to save
time.  However, it's also used by the parent pointers code to enable the
attr fork in preparation to receive ppptr xattrs.  This results in
xfs_has_parent() branches scattered around the codebase to turn on
INIT_XATTRS.

Linkable files are created far more commonly than unlinkable temporary
files or directory tree roots, so we should centralize this logic in
xfs_inode_init.  For the three callers that don't want parent pointers
(online repiar tempfiles, unlinkable tempfiles, rootdir creation) we
provide an UNLINKABLE flag to skip attr fork initialization.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:36:58 -07:00
Darrick J. Wong
c0223b8d66 xfs: wrap inode creation dqalloc calls
Create a helper that calls dqalloc to allocate and grab a reference to
dquots for the user, group, and project ids listed in an icreate
structure.  This simplifies the creat-related dqalloc callsites
scattered around the code base.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:36:57 -07:00
Darrick J. Wong
ba4b39fe4c xfs: pack icreate initialization parameters into a separate structure
Callers that want to create an inode currently pass all possible file
attribute values for the new inode into xfs_init_new_inode as ten
separate parameters.  This causes two code maintenance issues: first, we
have large multi-line call sites which programmers must read carefully
to make sure they did not accidentally invert a value.  Second, all
three file id parameters must be passed separately to the quota
functions; any discrepancy results in quota count errors.

Clean this up by creating a new icreate_args structure to hold all this
information, some helpers to initialize them properly, and make the
callers pass this structure through to the creation function, whose name
we shorten to xfs_icreate.  This eliminates the issues, enables us to
keep the inode init code in sync with userspace via libxfs, and is
needed for future metadata directory tree management.

(A subsequent cleanup will also fix the quota alloc calls.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:36:56 -07:00
Wenchao Hao
a330cae8a7 xfs: Remove header files which are included more than once
Following warning is reported, so remove these duplicated header
including:

./fs/xfs/libxfs/xfs_trans_resv.c: xfs_da_format.h is included more than once.
./fs/xfs/scrub/quota_repair.c: xfs_format.h is included more than once.
./fs/xfs/xfs_handle.c: xfs_da_btree.h is included more than once.
./fs/xfs/xfs_qm_bhv.c: xfs_mount.h is included more than once.
./fs/xfs/xfs_trace.c: xfs_bmap.h is included more than once.

This is just a clean code, no logic changed.

Signed-off-by: Wenchao Hao <haowenchao22@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-07-01 09:32:29 +05:30
Darrick J. Wong
95b19e2f4e xfs: don't open-code u64_to_user_ptr
Don't open-code what the kernel already provides.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-05-27 15:55:52 +05:30
Darrick J. Wong
2b3f004d3d xfs: drop xfarray sortinfo folio on error
Chandan Babu reports the following livelock in xfs/708:

 run fstests xfs/708 at 2024-05-04 15:35:29
 XFS (loop16): EXPERIMENTAL online scrub feature in use. Use at your own risk!
 XFS (loop5): Mounting V5 Filesystem e96086f0-a2f9-4424-a1d5-c75d53d823be
 XFS (loop5): Ending clean mount
 XFS (loop5): Quotacheck needed: Please wait.
 XFS (loop5): Quotacheck: Done.
 XFS (loop5): EXPERIMENTAL online scrub feature in use. Use at your own risk!
 INFO: task xfs_io:143725 blocked for more than 122 seconds.
       Not tainted 6.9.0-rc4+ #1
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:xfs_io          state:D stack:0     pid:143725 tgid:143725 ppid:117661 flags:0x00004006
 Call Trace:
  <TASK>
  __schedule+0x69c/0x17a0
  schedule+0x74/0x1b0
  io_schedule+0xc4/0x140
  folio_wait_bit_common+0x254/0x650
  shmem_undo_range+0x9d5/0xb40
  shmem_evict_inode+0x322/0x8f0
  evict+0x24e/0x560
  __dentry_kill+0x17d/0x4d0
  dput+0x263/0x430
  __fput+0x2fc/0xaa0
  task_work_run+0x132/0x210
  get_signal+0x1a8/0x1910
  arch_do_signal_or_restart+0x7b/0x2f0
  syscall_exit_to_user_mode+0x1c2/0x200
  do_syscall_64+0x72/0x170
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The shmem code is trying to drop all the folios attached to a shmem
file and gets stuck on a locked folio after a bnobt repair.  It looks
like the process has a signal pending, so I started looking for places
where we lock an xfile folio and then deal with a fatal signal.

I found a bug in xfarray_sort_scan via code inspection.  This function
is called to set up the scanning phase of a quicksort operation, which
may involve grabbing a locked xfile folio.  If we exit the function with
an error code, the caller does not call xfarray_sort_scan_done to put
the xfile folio.  If _sort_scan returns an error code while si->folio is
set, we leak the reference and never unlock the folio.

Therefore, change xfarray_sort to call _scan_done on exit.  This is safe
to call multiple times because it sets si->folio to NULL and ignores a
NULL si->folio.  Also change _sort_scan to use an intermediate variable
so that we never pollute si->folio with an errptr.

Fixes: 232ea05277 ("xfs: enable sorting of xfile-backed arrays")
Reported-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-05-27 15:55:52 +05:30
Steven Rostedt (Google)
2c92ca849f tracing/treewide: Remove second parameter of __assign_str()
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.

This means that with:

  __string(field, mystring)

Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.

There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:

  git grep -l __assign_str | while read a ; do
      sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
      mv /tmp/test-file $a;
  done

I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.

Note, the same updates will need to be done for:

  __assign_str_len()
  __assign_rel_str()
  __assign_rel_str_len()

I tested this with both an allmodconfig and an allyesconfig (build only for both).

[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/

Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>	# xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
2024-05-22 20:14:47 -04:00
Darrick J. Wong
204a26aa1d xfs: create a helper to compute the blockcount of a max sized remote value
Create a helper function to compute the number of fsblocks needed to
store a maximally-sized extended attribute value.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-05-02 07:48:36 -07:00
Christoph Hellwig
6773da870a xfs: fix error returns from xfs_bmapi_write
xfs_bmapi_write can return 0 without actually returning a mapping in
mval in two different cases:

 1) when there is absolutely no space available to do an allocation
 2) when converting delalloc space, and the allocation is so small
    that it only covers parts of the delalloc extent before the
    range requested by the caller

Callers at best can handle one of these cases, but in many cases can't
cope with either one.  Switch xfs_bmapi_write to always return a
mapping or return an error code instead.  For case 1) above ENOSPC is
the obvious choice which is very much what the callers expect anyway.
For case 2) there is no really good error code, so pick a funky one
from the SysV streams portfolio.

This fixes the reproducer here:

    https://lore.kernel.org/linux-xfs/CAEJPjCvT3Uag-pMTYuigEjWZHn1sGMZ0GCjVVCv29tNHK76Cgg@mail.gmail.com0/

which uses reserved blocks to create file systems that are gravely
out of space and thus cause at least xfs_file_alloc_space to hang
and trigger the lack of ENOSPC handling in xfs_dquot_disk_alloc.

Note that this patch does not actually make any caller but
xfs_alloc_file_space deal intelligently with case 2) above.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: 刘通 <lyutoon@gmail.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-04-30 09:45:18 +05:30
Christoph Hellwig
e58ac1770d xfs: refactor dir format helpers
Add a new enum and a xfs_dir2_format helper that returns it to allow
the code to switch on the format of a directory in a single operation
and switch all helpers of xfs_dir2_isblock and xfs_dir2_isleaf to it.

This also removes the explicit xfs_iread_extents call in a few of the
call sites given that xfs_bmap_last_offset already takes care of it
underneath.

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>
2024-04-26 11:21:46 +05:30
Christoph Hellwig
dfe5febe2b xfs: factor out a xfs_dir_replace_args helper
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>
2024-04-26 11:19:04 +05:30
Christoph Hellwig
3866e6e669 xfs: factor out a xfs_dir_removename_args helper
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>
2024-04-26 11:19:04 +05:30
Christoph Hellwig
4d893a4051 xfs: factor out a xfs_dir_createname_args helper
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>
2024-04-26 11:19:03 +05:30
Christoph Hellwig
14ee22fef4 xfs: factor out a xfs_dir_lookup_args helper
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>
2024-04-26 11:19:03 +05:30
Jiapeng Chong
08e012a62d xfs: Remove unused function xrep_dir_self_parent
The function are defined in the dir_repair.c file, but not called
elsewhere, so delete the unused function.

fs/xfs/scrub/dir_repair.c:186:1: warning: unused function 'xrep_dir_self_parent'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8867
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-04-24 12:34:44 +05:30
Darrick J. Wong
5e1c7d0b29 xfs: invalidate dentries for a file before moving it to the orphanage
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>
2024-04-23 16:55:19 -07:00
Darrick J. Wong
6d335233fe xfs: exchange-range for repairs is no longer dynamic
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>
2024-04-23 16:55:19 -07:00
Darrick J. Wong
b44bfc0695 xfs: fix iunlock calls in xrep_adoption_trans_alloc
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>
2024-04-23 16:55:19 -07:00
Darrick J. Wong
6691753752 xfs: drop the scrub file's iolock when transaction allocation fails
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>
2024-04-23 16:55:18 -07:00
Darrick J. Wong
4ad350ac58 xfs: only iget the file once when doing vectored scrub-by-handle
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>
2024-04-23 16:55:18 -07:00
Darrick J. Wong
b27ce0da60 xfs: use dontcache for grabbing inodes during scrub
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>
2024-04-23 16:55:18 -07:00
Darrick J. Wong
c77b37584c xfs: introduce vectored scrub mode
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>
2024-04-23 16:55:18 -07:00
Darrick J. Wong
be7cf174e9 xfs: move xfs_ioc_scrub_metadata to scrub.c
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>
2024-04-23 16:55:17 -07:00
Darrick J. Wong
271557de7c xfs: reduce the rate of cond_resched calls inside scrub
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>
2024-04-23 16:55:17 -07:00
Darrick J. Wong
3f31406aef xfs: fix corruptions in the directory tree
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>
2024-04-23 16:55:17 -07:00
Darrick J. Wong
37056912d5 xfs: report directory tree corruption in the health information
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>
2024-04-23 16:55:17 -07:00
Darrick J. Wong
d54c5ac80f xfs: invalidate dirloop scrub path data when concurrent updates happen
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>
2024-04-23 16:55:16 -07:00
Darrick J. Wong
928b721a11 xfs: teach online scrub to find directory tree structure problems
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>
2024-04-23 16:55:16 -07:00
Darrick J. Wong
327ed702d8 xfs: inode repair should ensure there's an attr fork to store parent pointers
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>
2024-04-23 16:55:16 -07:00
Darrick J. Wong
3f50ddbf4b xfs: repair link count of nondirectories after rebuilding parent pointers
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>
2024-04-23 16:55:16 -07:00
Darrick J. Wong
7be3d20bbe xfs: adapt the orphanage code to handle parent pointers
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>
2024-04-23 16:55:15 -07:00
Darrick J. Wong
a26dc21309 xfs: actually rebuild the parent pointer xattrs
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>
2024-04-23 16:55:15 -07:00
Darrick J. Wong
6efbbdeb14 xfs: add a per-leaf block callback to xchk_xattr_walk
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>
2024-04-23 16:55:15 -07:00
Darrick J. Wong
65a1fb7a11 xfs: implement live updates for parent pointer repairs
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>
2024-04-23 16:55:14 -07:00
Darrick J. Wong
b334f7fab5 xfs: repair directory parent pointers by scanning for dirents
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>
2024-04-23 16:55:14 -07:00
Darrick J. Wong
e5d7ce0364 xfs: replay unlocked parent pointer updates that accrue during xattr repair
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>
2024-04-23 16:55:14 -07:00
Darrick J. Wong
8559b21a64 xfs: implement live updates for directory repairs
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>
2024-04-23 16:55:13 -07:00
Darrick J. Wong
76fc23b695 xfs: repair directories by scanning directory parent pointers
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>
2024-04-23 16:55:13 -07:00
Darrick J. Wong
086e934fe9 xfs: salvage parent pointers when rebuilding xattr structures
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>
2024-04-23 07:47:03 -07:00
Darrick J. Wong
bf61c36a45 xfs: make the reserved block permission flag explicit in xfs_attr_set
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>
2024-04-23 07:47:03 -07:00
Darrick J. Wong
e7420e75ef xfs: remove some boilerplate from xfs_attr_set
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>
2024-04-23 07:47:03 -07:00
Darrick J. Wong
59a2af9086 xfs: check parent pointer xattrs when scrubbing
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>
2024-04-23 07:47:03 -07:00
Darrick J. Wong
77ede5f44b xfs: walk directory parent pointers to determine backref count
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>
2024-04-23 07:47:03 -07:00
Darrick J. Wong
8ad345306d xfs: deferred scrub of parent pointers
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>
2024-04-23 07:47:02 -07:00
Darrick J. Wong
0d29a20fbd xfs: scrub parent pointers
Actually check parent pointers now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-23 07:47:02 -07:00
Darrick J. Wong
b961c8bf1f xfs: deferred scrub of dirents
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>
2024-04-23 07:47:02 -07:00
Darrick J. Wong
61b3f0df5c xfs: check dirents have parent pointers
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>
2024-04-23 07:47:02 -07:00
Darrick J. Wong
2a009397eb xfs: revert commit 44af6c7e59
In my haste to fix what I thought was a performance problem in the attr
scrub code, I neglected to notice that the xfs_attr_get_ilocked also had
the effect of checking that attributes can actually be looked up through
the attr dabtree.  Fix this.

Fixes: 44af6c7e59 ("xfs: don't load local xattr values during scrub")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-23 07:47:01 -07:00