[ Upstream commit 5d1116d4c6 ]
Christoph Hellwig complained about the following soft lockup warning
when running scrub after generic/175 when preemption is disabled and
slub debugging is enabled:
watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [xfs_scrub:161]
Modules linked in:
irq event stamp: 41692326
hardirqs last enabled at (41692325): [<ffffffff8232c3b7>] _raw_0
hardirqs last disabled at (41692326): [<ffffffff81001c5a>] trace0
softirqs last enabled at (41684994): [<ffffffff8260031f>] __do_e
softirqs last disabled at (41684987): [<ffffffff81127d8c>] irq_e0
CPU: 3 PID: 16189 Comm: xfs_scrub Not tainted 5.4.0-rc3+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.124
RIP: 0010:_raw_spin_unlock_irqrestore+0x39/0x40
Code: 89 f3 be 01 00 00 00 e8 d5 3a e5 fe 48 89 ef e8 ed 87 e5 f2
RSP: 0018:ffffc9000233f970 EFLAGS: 00000286 ORIG_RAX: ffffffffff3
RAX: ffff88813b398040 RBX: 0000000000000286 RCX: 0000000000000006
RDX: 0000000000000006 RSI: ffff88813b3988c0 RDI: ffff88813b398040
RBP: ffff888137958640 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00042b0c00
R13: 0000000000000001 R14: ffff88810ac32308 R15: ffff8881376fc040
FS: 00007f6113dea700(0000) GS:ffff88813bb80000(0000) knlGS:00000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6113de8ff8 CR3: 000000012f290000 CR4: 00000000000006e0
Call Trace:
free_debug_processing+0x1dd/0x240
__slab_free+0x231/0x410
kmem_cache_free+0x30e/0x360
xchk_ag_btcur_free+0x76/0xb0
xchk_ag_free+0x10/0x80
xchk_bmap_iextent_xref.isra.14+0xd9/0x120
xchk_bmap_iextent+0x187/0x210
xchk_bmap+0x2e0/0x3b0
xfs_scrub_metadata+0x2e7/0x500
xfs_ioc_scrub_metadata+0x4a/0xa0
xfs_file_ioctl+0x58a/0xcd0
do_vfs_ioctl+0xa0/0x6f0
ksys_ioctl+0x5b/0x90
__x64_sys_ioctl+0x11/0x20
do_syscall_64+0x4b/0x1a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
If preemption is disabled, all metadata buffers needed to perform the
scrub are already in memory, and there are a lot of records to check,
it's possible that the scrub thread will run for an extended period of
time without sleeping for IO or any other reason. Then the watchdog
timer or the RCU stall timeout can trigger, producing the backtrace
above.
To fix this problem, call cond_resched() from the scrub thread so that
we back out to the scheduler whenever necessary.
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Removed unused error variable. Instead of using error variable,
returned the value directly as it wasn't updated.
Signed-off-by: Aliasgar Surti <aliasgar.surti500@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Returned value directly instead of using variable as it wasn't updated.
Signed-off-by: Aliasgar Surti <aliasgar.surti500@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Shortform, leaf and remote value attr value retrieval return
different values for success. This makes it more complex to handle
actual errors xfs_attr_get() as some errors mean success and some
mean failure. Make the return values consistent for success and
failure consistent for all attribute formats.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Use -ECANCELED to signal "stop iterating" instead of these magical
*_ITER_ABORT values, since it's duplicative.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
xfs_trans_log_buf() takes a final argument of the last byte to
log in the buffer; b_length is in basic blocks, so this isn't
the correct last byte. Fix it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The inode block mapping scrub function does more work for btree format
extent maps than is absolutely necessary -- first it will walk the bmbt
and check all the entries, and then it will load the incore tree and
check every entry in that tree, possibly for a second time.
Simplify the code and decrease check runtime by separating the two
responsibilities. The bmbt walk will make sure the incore extent
mappings are loaded, check the shape of the bmap btree (via xchk_btree)
and check that every bmbt record has a corresponding incore extent map;
and the incore extent map walk takes all the responsibility for checking
the mapping records and cross referencing them with other AG metadata.
This enables us to clean up some messy parameter handling and reduce
redundant code. Rename a few functions to make the split of
responsibilities clearer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP,
we can remove KM_NOSLEEP and replace KM_SLEEP with 0.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
In xchk_da_btree_block_check_sibling(), there is an if statement on
line 274 to check whether ds->state->altpath.blk[level].bp is NULL:
if (ds->state->altpath.blk[level].bp)
When ds->state->altpath.blk[level].bp is NULL, it is used on line 281:
xfs_trans_brelse(..., ds->state->altpath.blk[level].bp);
struct xfs_buf_log_item *bip = bp->b_log_item;
ASSERT(bp->b_transp == tp);
Thus, possible null-pointer dereferences may occur.
To fix these bugs, ds->state->altpath.blk[level].bp is checked before
being used.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The xattr scrubber functions use the temporary memory buffer either for
storing bitmaps or for testing if attribute value extraction works. The
bitmap code always zeroes what it needs and the value extraction sets
the buffer contents, so it's not necessary to waste CPU time zeroing on
allocation.
Note that while we never read the contents that the attr value
extraction function sets, we do need to call it to check the remote
attribute header and CRCs to check for corruption.
A flame graph analysis showed that we were spending 7% of a xfs_scrub
run (the whole program, not just the attr scrubber itself) allocating
and zeroing 64k segments needlessly.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
In examining a flame graph of time spent running xfs_scrub on various
filesystems, I noticed that we spent nearly 7% of the total runtime on
allocating a zeroed 65k buffer for every SCRUB_TYPE_XATTR invocation.
We do this even if none of the attribute values were anywhere near 64k
in size, even if there were no attribute blocks to check space on, and
even if it just turns out there are no attributes at all.
Therefore, rearrange the xattr buffer setup code to support reallocating
with a bigger buffer and redistribute the callers of that function so
that we only allocate memory just prior to needing it, and only allocate
as much as we need. If we can't get memory with the ILOCK held we'll
bail out with EDEADLOCK which will allocate the maximum memory.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Move the code that allocates memory buffers for the extended attribute
scrub code into a separate function so we can reduce memory allocations
in the next patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Replace the open-coded attribute buffer pointer calculations with helper
functions to make it more obvious what we're doing with our freeform
memory allocation w.r.t. either storing xattr values or computing btree
block free space.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
When we're iterating all the attributes using the built-in xattr
iterator, we can use the seen_enough variable to pass error codes back
to the main scrub function instead of flattening them into 0/1. This
will be used in a more exciting fashion in upcoming patches.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Currently, xfs doesn't have generic error codes defined for "stop
iterating"; we just reuse the XFS_BTREE_QUERY_* return values. This
looks a little weird if we're not actually iterating a btree index.
Before we start adding more iterators, we should create general
XFS_ITER_{CONTINUE,ABORT} return values and define the XFS_BTREE_QUERY_*
ones from that.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.
nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this. I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
There are several functions which take a flag argument that is
only ever passed as "0," so remove these arguments.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Separate the inode geometry information into a distinct structure.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The im_boffset field is in units of bytes, whereas XFS_INO_OFFSET
returns a value in units of inodes. Convert the units so that scrub on
a 64k-block filesystem works correctly.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Teach online scrub how to check the filesystem summary counters. We use
the incore delalloc block counter along with the incore AG headers to
compute expected values for fdblocks, icount, and ifree, and then check
that the percpu counter is within a certain threshold of the expected
value. This is done to avoid having to freeze or otherwise lock the
filesystem, which means that we're only checking that the counters are
fairly close, not that they're exactly correct.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
In theory, the incore per-AG structure counters should match the ones on
disk, so check that.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The forthcoming summary counter patch races with regular filesystem
activity to compute rough expected values for the counters. This design
was chosen to avoid having to freeze the entire filesystem to check the
counters, but while that's running we'd prefer to minimize background
reclamation activity to reduce the perturbations to the incore free
block count. Therefore, provide a way for scrubbers to disable
background posteof and cowblock reclamation.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
In xrep_roll_ag_trans, the transaction roll will always set sc->tp to
the new transaction, even if committing the old one fails. A bare
transaction roll leaves the buffer(s) locked but not joined to the new
transaction, so it's not necessary to release the hold if the roll
fails. Remove the incorrect xfs_trans_bhold_release calls.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Skip cross-referencing with a btree if the health report tells us that
it's known to be bad. This should reduce the dmesg spew considerably.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now that we have the ability to track sick metadata in-core, make scrub
and repair update those health assessments after doing work.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now that we no longer memset the scrub context, we can move the
already_fixed variable into the scrub context's state flags instead of
passing around pointers to separate stack variables.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Combine all the boolean state flags in struct xfs_scrub into a single
unsigned int, because we're going to be adding more state flags soon.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
It's a little silly how the memset in scrub context initialization
forces us to declare stack variables to preserve context variables
across a retry. Since the teardown functions already null out most of
the ephemeral state (buffer pointers, btree cursors, etc.), just skip
the memset and move the initialization as needed.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
In xchk_btree_check_owner, we can be passed a null buffer pointer. This
should only happen for the root of a root-in-inode btree type, but we
should program defensively in case the btree cursor state ever gets
screwed up and we get a null buffer anyway.
Coverity-id: 1438713
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Make sure scrub's dabtree iterator function checks that we're not
going deeper in the stack than our cursor permits.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Fix a backwards endian conversion of a constant.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
A previous commit removed the initialization of variable 'error' to zero,
and can cause a bogus error return. This occurs when error contains a
non-zero garbage value and the call to xchk_should_terminate detects a
pending fatal signal and checks for a zero error before setting it
to -EAGAIN. Fix the issue by initializing error to zero.
Fixes: b9454fe056 ("xfs: clean up the inode cluster checking in the inobt scrub")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Now that we encode block magic numbers in all the buffer ops, use that
for block type detection in the ag header repair code instead of
encoding magics directly in the repair code.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Similar to the inode btree verifier, the same allocation btree
verifier structure is shared between the by-bno (bnobt) and by-size
(cntbt) btrees. This prevents the ability to distinguish magic
values between them. Separate the verifier into two, one for each
tree, and assign them appropriately. No functional changes.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The inobt verifier is reused for the inobt and finobt, which
prevents the ability to distinguish between magic values on a
per-tree basis. Create a separate finobt structure in preparation
for changes to enforce the appropriate magic value for the
associated tree. This patch has no functional change.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Add a new helper to check that a per-AG inode pointer is either null or
points somewhere valid within that AG.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Check extended attribute entry names for invalid characters.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Check directory entry names for invalid characters.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Fix an off-by-one error in the realtime bitmap "is used" cross-reference
helper function if the realtime extent size is a single block.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Teach scrub to flag extent maps that exceed the range that can be mapped
with a xfs_dablk_t.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The extended attribute scrubber should abort the "read all attrs" loop
if there's a fatal signal pending on the process.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Move all the confusing dinode mapping code that's split between
xchk_iallocbt_check_cluster and xchk_iallocbt_check_cluster_ifree into
the first function so that it's clearer how we find the dinode for a
given inode.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Teach scrub how to handle the case that there are one or more inobt
records covering a given inode cluster. This fixes the operation on big
block filesystems (e.g. 64k blocks, 512 byte inodes).
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The code to check inobt records against inode clusters is a mess of
poorly named variables and unnecessary parameters. Clean the
unnecessary inode number parameters out of _check_cluster_freemask in
favor of computing them inside the function instead of making the caller
do it. In xchk_iallocbt_check_cluster, rename the variables to make it
more obvious just what chunk_ino and cluster_ino represent.
Add a tracepoint to make it easier to track each inode cluster as we
scrub it.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Hoist the inode cluster checks out of the inobt record check loop into
a separate function in preparation for refactoring of that loop. No
functional changes here; that's in the next patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
On a big block filesystem, there may be multiple inobt records covering
a single inode cluster. These records obviously won't be aligned to
cluster alignment rules, and they must cover the entire cluster. Teach
scrub to check for these things.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
In xchk_iallocbt_rec, check the alignment of ir_startino by converting
the inode cluster block alignment into units of inodes instead of the
other way around (converting ir_startino to blocks). This prevents us
from tripping over off-by-one errors in ir_startino which are obscured
by the inode -> block conversion.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Make sure we never check more than XFS_INODES_PER_CHUNK inodes for any
given inobt record since there can be more than one inobt record mapped
to an inode cluster.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
In xrep_findroot_block, we work out the btree type and correctness of a
given block by calling different btree verifiers on root block
candidates. However, we leave the NULL b_ops while ->verify_read
validates the block, which means that if the verifier calls
xfs_buf_verifier_error it'll crash on the null b_ops. Fix it to set
b_ops before calling the verifier and unsetting it if the verifier
fails.
Furthermore, improve the documentation around xfs_buf_ensure_ops, which
is the function that is responsible for cleaning up the b_ops state of
buffers that go through xrep_findroot_block but don't match anything.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Use __print_symbolic to print the scrub type in ftrace output.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Darrick J. Wong