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>
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 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>
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>
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>
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>
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>
When a file-based metadata structure is being scrubbed in
xchk_metadata_inode_subtype, we should create an entirely new scrub
context so that each scrubber doesn't trip over another's buffers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If a symbolic link target looks bad, try to sift through the rubble to
find as much of the target buffer that we can, and stage a new target
(short or remote format as needed) in a temporary file and use the
atomic extent swapping mechanism to commit the results. In the worst
case, we replace the target with an overly long filename that cannot
possibly resolve.
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>
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>
If a directory looks like it's in bad shape, try to sift through the
rubble to find whatever directory entries we can, scan the directory
tree for the parent (if needed), stage the new directory contents in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If the extended attributes look bad, try to sift through the rubble to
find whatever keys/values we can, stage a new attribute structure in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Repair the realtime summary data by constructing a new rtsummary file in
the scrub temporary file, then atomically swapping the contents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create some new routines to exchange the contents of a temporary file
created to stage a repair with another ondisk file. This will be used
by the realtime summary repair function to commit atomically the new
rtsummary data, which will be staged in the tempfile.
The rest of XFS coordinates access to the realtime metadata inodes
solely through the ILOCK. For repair to hold its exclusive access to
the realtime summary file, it has to allocate a single large transaction
and roll it repeatedly throughout the repair while holding the ILOCK.
In turn, this means that for now there's only a partial file mapping
exchange implementation for the temporary file because we can only work
within an existing transaction.
For now, the only tempswap functions needed here are to estimate the
resource requirements of the exchange, reserve more space/quota to an
existing transaction, and kick off the actual exchange. The rest will
be added in a later patch in preparation for repairing xattrs and
directories.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Teach the online repair code how to create temporary files or
directories. These temporary files can be used to stage reconstructed
information until we're ready to perform an atomic extent swap to commit
the new metadata.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Hook the regular rmap code when an rmapbt repair operation is running so
that we can unlock the AGF buffer to scan the filesystem and keep the
in-memory btree up to date during the scan.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Rebuild the reverse mapping btree from all primary metadata. This first
patch establishes the bare mechanics of finding records and putting
together a new ondisk tree; more complex pieces are needed to make it
work properly.
Link: Documentation/filesystems/xfs-online-fsck-design.rst
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Adapt the generic btree cursor code to be able to create a btree whose
buffers come from a (presumably in-memory) buftarg with a header block
that's specific to in-memory btrees. We'll connect this to other parts
of online scrub in the next patches.
Note that in-memory btrees always have a block size matching the system
memory page size for efficiency reasons. There are also a few things we
need to do to finalize a btree update; that's covered in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the same summary counter calculation infrastructure to generate new
values for the in-core summary counters. The difference between the
scrubber and the repairer is that the repairer will freeze the fs during
setup, which means that the values should match exactly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If scrub finds that everything is ok with the filesystem, we need a way
to tell the health tracking that it can let go of indirect health flags,
since indirect flags only mean that at some point in the past we lost
some context.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fix the file link counts since we just computed the correct ones.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create the necessary hooks in the directory operations
(create/link/unlink/rename) code so that our live nlink scrub code can
stay up to date with link count updates in the rest of the filesystem.
This will be the means to keep our shadow link count information up to
date while the scan runs in real time.
In online fsck part 2, we'll use these same hooks to handle repairs
to directories and parent pointer information.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create the necessary scrub code to walk the filesystem's directory tree
so that we can compute file link counts. Similar to quotacheck, we
create an incore shadow array of link count information and then we walk
the filesystem a second time to compare the link counts. We need live
updates to keep the information up to date during the lengthy scan, so
this scrubber remains disabled until the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the shadow quota counters that live quotacheck creates to reset the
incore dquot counters.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a shadow dqtrx system in the quotacheck code that hooks the
regular dquot counter update code. This will be the means to keep our
copy of the dquot counters up to date while the scan runs in real time.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a new trio of scrub functions to check quota counters. While the
dquots themselves are filesystem metadata and should be checked early,
the dquot counter values are computed from other metadata and are
therefore summary counters. We don't plug these into the scrub dispatch
just yet, because we still need to be able to watch quota updates while
doing our scan.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fix all the file metadata surrounding the realtime bitmap file, which
includes the rt geometry, file size, forks, and space mappings. The
bitmap contents themselves cannot be fixed without rt rmap, so that will
come later.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
XFS filesystems always have a realtime bitmap and summary file, even if
there has never been a realtime volume attached. Always check them.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Try to repair errors that we see in file CoW forks so that we don't do
stupid things like remap garbage into a file. There's not a lot we can
do with the COW fork -- the ondisk metadata record only that the COW
staging extents are owned by the refcount btree, which effectively means
that we can't reconstruct this incore structure from scratch.
Actually, this is even worse -- we can't touch written extents, because
those map space that are actively under writeback, and there's not much
to do with delalloc reservations. Hence we can only detect crosslinked
unwritten extents and fix them by punching out the problematic parts and
replacing them with delalloc extents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There are a couple of conditions that userspace can set to force repairs
of metadata. These really belong in the repair code and not open-coded
into the check code, so refactor them into a helper.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the reverse-mapping btree information to rebuild an inode block map.
Update the btree bulk loading code as necessary to support inode rooted
btrees and fix some bitrot problems.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
If an inode is so badly damaged that it cannot be loaded into the cache,
fix the ondisk metadata and try again. If there /is/ a cached inode,
fix any problems and apply any optimizations that can be solved incore.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Use the rmapbt to find inode chunks, query the chunks to compute hole
and free masks, and with that information rebuild the inobt and finobt.
Refer to the case study in
Documentation/filesystems/xfs-online-fsck-design.rst for more details.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Rebuild the free space btrees from the gaps in the rmap btree. Refer to
the case study in Documentation/filesystems/xfs-online-fsck-design.rst
for more details.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Christoph Hellwig complained about awkward code in the next two repair
patches such as:
sc->sm->sm_type = XFS_SCRUB_TYPE_BNOBT;
error = xchk_bnobt(sc);
This is a little silly, so let's export the xchk_{,i}allocbt functions
to the dispatch table in scrub.c directly and get rid of the helpers.
Originally I had planned each btree gets its own separate entry point,
but since repair doesn't work that way, it no longer makes sense to
complicate the call chain that way.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Harshit Mogalapalli slogged through several reports from our internal
syzbot instance and observed that they all had a common stack trace:
BUG: KASAN: user-memory-access in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: user-memory-access in atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1294 [inline]
BUG: KASAN: user-memory-access in queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
BUG: KASAN: user-memory-access in do_raw_spin_lock include/linux/spinlock.h:187 [inline]
BUG: KASAN: user-memory-access in __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
BUG: KASAN: user-memory-access in _raw_spin_lock+0x76/0xe0 kernel/locking/spinlock.c:154
Write of size 4 at addr 0000001dd87ee280 by task syz-executor365/1543
CPU: 2 PID: 1543 Comm: syz-executor365 Not tainted 6.5.0-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x83/0xb0 lib/dump_stack.c:106
print_report+0x3f8/0x620 mm/kasan/report.c:478
kasan_report+0xb0/0xe0 mm/kasan/report.c:588
check_region_inline mm/kasan/generic.c:181 [inline]
kasan_check_range+0x139/0x1e0 mm/kasan/generic.c:187
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1294 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
do_raw_spin_lock include/linux/spinlock.h:187 [inline]
__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
_raw_spin_lock+0x76/0xe0 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
xchk_stats_merge_one.isra.1+0x39/0x650 fs/xfs/scrub/stats.c:191
xchk_stats_merge+0x5f/0xe0 fs/xfs/scrub/stats.c:225
xfs_scrub_metadata+0x252/0x14e0 fs/xfs/scrub/scrub.c:599
xfs_ioc_scrub_metadata+0xc8/0x160 fs/xfs/xfs_ioctl.c:1646
xfs_file_ioctl+0x3fd/0x1870 fs/xfs/xfs_ioctl.c:1955
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl fs/ioctl.c:857 [inline]
__x64_sys_ioctl+0x199/0x220 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3e/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7ff155af753d
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1b 79 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc006e2568 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff155af753d
RDX: 00000000200000c0 RSI: 00000000c040583c RDI: 0000000000000003
RBP: 00000000ffffffff R08: 00000000004010c0 R09: 00000000004010c0
R10: 00000000004010c0 R11: 0000000000000246 R12: 0000000000400cb0
R13: 00007ffc006e2670 R14: 0000000000000000 R15: 0000000000000000
</TASK>
The root cause here is that xchk_stats_merge_one walks off the end of
the xchk_scrub_stats.cs_stats array because it has been fed a garbage
value in sm->sm_type. That occurs because I put the xchk_stats_merge
in the wrong place -- it should have been after the last xchk_teardown
call on our way out of xfs_scrub_metadata because we only call the
teardown function if we called the setup function, and we don't call the
setup functions if the inputs are obviously garbage.
Thanks to Harshit for triaging the bug reports and bringing this to my
attention.
Fixes: d7a74cad8f ("xfs: track usage statistics of online fsck")
Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
* Chandan Babu will be taking over as the XFS release manager. He has
reviewed all the patches that are in this branch, though I'm signing
the branch one last time since I'm still technically maintainer. :P
* Create a maintainer entry profile for XFS in which we lay out the
various roles that I have played for many years. Aside from release
manager, the remaining roles are as yet unfilled.
* Start merging online repair -- we now have in-memory pageable memory
for staging btrees, a bunch of pending fixes, and we've started the
process of refactoring the scrub support code to support more of
repair. In particular, reaping of old blocks from damaged structures.
* Scrub the realtime summary file.
* Fix a bug where scrub's quota iteration only ever returned the root
dquot. Oooops.
* Fix some typos.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQQ2qTKExjcn+O1o2YRKO3ySh0YRpgUCZOQE2AAKCRBKO3ySh0YR
pvmZAQDe+KceaVx6Dv2f9ihckeS2dILSpDTo1bh9BeXnt005VwD/ceHTaJxEl8lp
u/dixFDkRgp9RYtoTAK2WNiUxYetsAc=
=oZN6
-----END PGP SIGNATURE-----
Merge tag 'xfs-6.6-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
- Chandan Babu will be taking over as the XFS release manager. He has
reviewed all the patches that are in this branch, though I'm signing
the branch one last time since I'm still technically maintainer. :P
- Create a maintainer entry profile for XFS in which we lay out the
various roles that I have played for many years. Aside from release
manager, the remaining roles are as yet unfilled.
- Start merging online repair -- we now have in-memory pageable memory
for staging btrees, a bunch of pending fixes, and we've started the
process of refactoring the scrub support code to support more of
repair. In particular, reaping of old blocks from damaged structures.
- Scrub the realtime summary file.
- Fix a bug where scrub's quota iteration only ever returned the root
dquot. Oooops.
- Fix some typos.
[ Pull request from Chandan Babu, but signed tag and description from
Darrick Wong, thus the first person singular above is Darrick, not
Chandan ]
* tag 'xfs-6.6-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (37 commits)
fs/xfs: Fix typos in comments
xfs: fix dqiterate thinko
xfs: don't check reflink iflag state when checking cow fork
xfs: simplify returns in xchk_bmap
xfs: rewrite xchk_inode_is_allocated to work properly
xfs: hide xfs_inode_is_allocated in scrub common code
xfs: fix agf_fllast when repairing an empty AGFL
xfs: allow userspace to rebuild metadata structures
xfs: clear pagf_agflreset when repairing the AGFL
xfs: allow the user to cancel repairs before we start writing
xfs: don't complain about unfixed metadata when repairs were injected
xfs: implement online scrubbing of rtsummary info
xfs: always rescan allegedly healthy per-ag metadata after repair
xfs: move the realtime summary file scrubber to a separate source file
xfs: wrap ilock/iunlock operations on sc->ip
xfs: get our own reference to inodes that we want to scrub
xfs: track usage statistics of online fsck
xfs: improve xfarray quicksort pivot
xfs: create scaffolding for creating debugfs entries
xfs: cache pages used for xfarray quicksort convergence
...
Add a new (superuser-only) flag to the online metadata repair ioctl to
force it to rebuild structures, even if they're not broken. We will use
this to move metadata structures out of the way during a free space
defragmentation operation.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
While debugging other parts of online repair, I noticed that if someone
injects FORCE_SCRUB_REPAIR, starts an IFLAG_REPAIR scrub on a piece of
metadata, and the metadata repair fails, we'll log a message about
uncorrected errors in the filesystem.
This isn't strictly true if the scrub function didn't set OFLAG_CORRUPT
and we're only doing the repair because the error injection knob is set.
Repair functions are allowed to abort the entire operation at any point
before committing new metadata, in which case the piece of metadata is
in the same state as it was before. Therefore, the log message should
be gated on the results of the scrub. Refactor the predicate and
rearrange the code flow to make this happen.
Note: If the repair function errors out after it commits the new
metadata, the transaction cancellation will shut down the filesystem,
which is an obvious sign of corrupt metadata.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Finish the realtime summary scrubber by adding the functions we need to
compute a fresh copy of the rtsummary info and comparing it to the copy
on disk.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Scrub tracks the resources that it's holding onto in the xfs_scrub
structure. This includes the inode being checked (if applicable) and
the inode lock state of that inode. Replace the open-coded structure
manipulation with a trivial helper to eliminate sources of error.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
When we want to scrub a file, get our own reference to the inode
unconditionally. This will make disposal rules simpler in the long run.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Track the usage, outcomes, and run times of the online fsck code, and
report these values via debugfs. The columns in the file are:
* scrubber name
* number of scrub invocations
* clean objects found
* corruptions found
* optimizations found
* cross referencing failures
* inconsistencies found during cross referencing
* incomplete scrubs
* warnings
* number of time scrub had to retry
* cumulative amount of time spent scrubbing (microseconds)
* number of repair inovcations
* successfully repaired objects
* cumuluative amount of time spent repairing (microseconds)
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If the fscounters scrubber notices incorrect summary counters, it's
entirely possible that scrub is simply racing with other threads that
are updating the incore counters. There isn't a good way to stabilize
percpu counters or set ourselves up to observe live updates with hooks
like we do for the quotacheck or nlinks scanners, so we instead choose
to freeze the filesystem long enough to walk the incore per-AG
structures.
Past me thought that it was going to be commonplace to have to freeze
the filesystem to perform some kind of repair and set up a whole
separate infrastructure to freeze the filesystem in such a way that
userspace could not unfreeze while we were running. This involved
adding a mutex and freeze_super/thaw_super functions and dealing with
the fact that the VFS freeze/thaw functions can free the VFS superblock
references on return.
This was all very overwrought, since fscounters turned out to be the
only user of scrub freezes, and it doesn't require the log to quiesce,
only the incore superblock counters. We prevent other threads from
changing the freeze level by calling freeze_super_excl with a custom
freeze cookie to keep everyone else out of the filesystem.
The end result is that fscounters should be much more efficient. When
we're checking a busy system and we can't stabilize the counters, the
custom freeze will do less work, which should result in less downtime.
Repair should be similarly speedy, but that's in a later patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The fscounters scrub code doesn't work properly because it cannot
quiesce updates to the percpu counters in the filesystem, hence it
returns false corruption reports. This has been fixed properly in
one of the online repair patchsets that are under review by replacing
the xchk_disable_reaping calls with an exclusive filesystem freeze.
Disabling background gc isn't sufficient to fix the problem.
In other words, scrub doesn't need to call xfs_inodegc_stop, which is
just as well since it wasn't correct to allow scrub to call
xfs_inodegc_start when something else could be calling xfs_inodegc_stop
(e.g. trying to freeze the filesystem).
Neuter the scrubber for now, and remove the xchk_*_reaping functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
