Commit Graph

80971 Commits

Author SHA1 Message Date
Darrick J. Wong a03297a0ca xfs: manage inode DONTCACHE status at irele time
Right now, there are statements scattered all over the online fsck
codebase about how we can't use XFS_IGET_DONTCACHE because of concerns
about scrub's unusual practice of releasing inodes with transactions
held.

However, iget is the wrong place to handle this -- the DONTCACHE state
doesn't matter at all until we try to *release* the inode, and here we
get things wrong in multiple ways:

First, if we /do/ have a transaction, we must NOT drop the inode,
because the inode could have dirty pages, dropping the inode will
trigger writeback, and writeback can trigger a nested transaction.

Second, if the inode already had an active reference and the DONTCACHE
flag set, the icache hit when scrub grabs another ref will not clear
DONTCACHE.  This is sort of by design, since DONTCACHE is now used to
initiate cache drops so that sysadmins can change a file's access mode
between pagecache and DAX.

Third, if we do actually have the last active reference to the inode, we
can set DONTCACHE to avoid polluting the cache.  This is the /one/ case
where we actually want that flag.

Create an xchk_irele helper to encode all that logic and switch the
online fsck code to use it.  Since this now means that nearly all
scrubbers use the same xfs_iget flags, we can wrap them too.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:20 -07:00
Darrick J. Wong 0916056eba xfs: fix parent pointer scrub racing with subdirectory reparenting
Jan Kara pointed out that rename() doesn't lock a subdirectory that is
being moved from one parent to another, even though the move requires an
update to the subdirectory's dotdot entry.  This means that it's *not*
sufficient to hold a directory's IOLOCK to stabilize the dotdot entry.
We must hold the ILOCK of both the child and the alleged parent, and
there's no use in holding the parent's IOLOCK.

With that in mind, we can get rid of all the messy code that tries to
grab the parent's IOLOCK, which means we don't need to let go of the
ILOCK of the directory whose parent we are checking.  We still have to
use nonblocking mode to take the ILOCK of the alleged parent, so the
revalidation loop has to stay.

However, we can remove the retry counter, since threads aren't supposed
to hold the ILOCK for long periods of time.  Remove the inverted ilock
helper from the common code since nobody uses it.  Remove the entire
source of -EDEADLOCK-based "retry harder" scrub executions.

Link: https://lore.kernel.org/linux-xfs/20230117123735.un7wbamlbdihninm@quack3/
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:20 -07:00
Darrick J. Wong b049962c0f xfs: simplify xchk_parent_validate
This function is unnecessarily long because it contains code to
revalidate a dotdot entry after cycling locks to try to confirm a
subdirectory parent pointer.  Shorten the codebase by making the
parent's lookup call do double duty as the revalidation code.

This weakeans the efficacy of this scrub function temporarily, but the
next patch will resolve this as part of fixing an unhandled race that is
the result of the VFS rename locking model not working the way Darrick
thought it did.

Rename this stupid 'dnum' variable too.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:19 -07:00
Darrick J. Wong cbab28f4c0 xfs: remove xchk_parent_count_parent_dentries
This helper is now trivial, so get rid of it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:19 -07:00
Darrick J. Wong 6bb9209cee xfs: always check the existence of a dirent's child inode
When we're scrubbing directory entries, we always need to iget the child
inode to make sure that the inode pointer points to a valid inode.  The
original directory scrub code (commit a5c4) only set us up to do this
for ftype=1 filesystems, which is not sufficient; and then commit 4b80
made it worse by exempting the dot and dotdot entries.

Sorta-fixes: a5c46e5e89 ("xfs: scrub directory metadata")
Sorta-fixes: 4b80ac6445 ("xfs: scrub should mark a directory corrupt if any entries cannot be iget'd")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:18 -07:00
Darrick J. Wong d9a94480f9 xfs: xfs_iget in the directory scrubber needs to use UNTRUSTED
In commit 4b80ac6445, we tried to strengthen the directory scrubber by
using the iget call to detect directory entries that point to
unallocated inodes.  Unfortunately, that commit neglected to pass
XFS_IGET_UNTRUSTED to xfs_iget, so we don't check the inode btree first.
If the inode number points to something that isn't even an inode
cluster, iget will throw corruption errors and return -EFSCORRUPTED,
which means that we fail to mark the directory corrupt.

Fixes: 4b80ac6445 ("xfs: scrub should mark a directory corrupt if any entries cannot be iget'd")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:17 -07:00
Darrick J. Wong 4c233b5c4f xfs: streamline the directory iteration code for scrub
Currently, online scrub reuses the xfs_readdir code to walk every entry
in a directory.  This isn't awesome for performance, since we end up
cycling the directory ILOCK needlessly and coding around the particular
quirks of the VFS dir_context interface.

Create a streamlined version of readdir that keeps the ILOCK (since the
walk function isn't going to copy stuff to userspace), skips a whole lot
of directory walk cursor checks (since we start at 0 and walk to the
end) and has a sane way to return error codes.

Note: Porting the dotdot checking code is left for a subsequent patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:17 -07:00
Darrick J. Wong 9dceccc582 xfs: use the directory name hash function for dir scrubbing
The directory code has a directory-specific hash computation function
that includes a modified hash function for case-insensitive lookups.
Hence we must use that function (and not the raw da_hashname) when
checking the dabtree structure.

Found by accidentally breaking xfs/188 to create an abnormally huge
case-insensitive directory and watching scrub break.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:16 -07:00
Darrick J. Wong 30f8ee5e7e xfs: ensure that single-owner file blocks are not owned by others
For any file fork mapping that can only have a single owner, make sure
that there are no other rmap owners for that mapping.  This patch
requires the more detailed checking provided by xfs_rmap_count_owners so
that we can know how many rmap records for a given range of space had a
matching owner, how many had a non-matching owner, and how many
conflicted with the records that have a matching owner.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:16 -07:00
Darrick J. Wong 69115f775f xfs: teach scrub to check for sole ownership of metadata objects
Strengthen online scrub's checking even further by enabling us to check
that a range of blocks are owned solely by a given owner.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:15 -07:00
Darrick J. Wong efc0845f5d xfs: convert xfs_ialloc_has_inodes_at_extent to return keyfill scan results
Convert the xfs_ialloc_has_inodes_at_extent function to return keyfill
scan results because for a given range of inode numbers, we might have
no indexed inodes at all; the entire region might be allocated ondisk
inodes; or there might be a mix of the two.

Unfortunately, sparse inodes adds to the complexity, because each inode
record can have holes, which means that we cannot use the generic btree
_scan_keyfill function because we must look for holes in individual
records to decide the result.  On the plus side, online fsck can now
detect sub-chunk discrepancies in the inobt.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:15 -07:00
Darrick J. Wong bc0f3b5546 xfs: directly cross-reference the inode btrees with each other
Improve the cross-referencing of the two inode btrees by directly
checking the free and hole state of each inode with the other btree.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:14 -07:00
Darrick J. Wong c01868b60e xfs: clean up broken eearly-exit code in the inode btree scrubber
Corrupt inode chunks should cause us to exit early after setting the
CORRUPT flag on the scrub state.  While we're at it, collapse trivial
helpers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:13 -07:00
Darrick J. Wong cc1207662d xfs: remove pointless shadow variable from xfs_difree_inobt
In xfs_difree_inobt, the pag passed in was previously used to look up
the AGI buffer.  There's no need to extract it again, so remove the
shadow variable and shut up -Wshadow.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:13 -07:00
Darrick J. Wong 7ac14fa2bd xfs: ensure that all metadata and data blocks are not cow staging extents
Make sure that all filesystem metadata blocks and file data blocks are
not also marked as CoW staging extents.  The extra checking added here
was inspired by an actual VM host filesystem corruption incident due to
bugs in the CoW handling of 4.x kernels.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:12 -07:00
Darrick J. Wong 7ad9ea6398 xfs: check the reference counts of gaps in the refcount btree
Gaps in the reference count btree are also significant -- for these
regions, there must not be any overlapping reverse mappings.  We don't
currently check this, so make the refcount scrubber more complete.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:12 -07:00
Darrick J. Wong 4a200a0978 xfs: implement masked btree key comparisons for _has_records scans
For keyspace fullness scans, we want to be able to mask off the parts of
the key that we don't care about.  For most btree types we /do/ want the
full keyspace, but for checking that a given space usage also has a full
complement of rmapbt records (even if different/multiple owners) we need
this masking so that we only track sparseness of rm_startblock, not the
whole keyspace (which is extremely sparse).

Augment the ->diff_two_keys and ->keys_contiguous helpers to take a
third union xfs_btree_key argument, and wire up xfs_rmap_has_records to
pass this through.  This third "mask" argument should contain a nonzero
value in each structure field that should be used in the key comparisons
done during the scan.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:11 -07:00
Darrick J. Wong 6abc7aef85 xfs: replace xfs_btree_has_record with a general keyspace scanner
The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range.  Unfortunately, that's not
sufficient for scrub.  We want to be able to tell if a range of keyspace
for a btree is devoid of records, is totally mapped to records, or is
somewhere in between.  By forcing this to be a boolean, we conflated
sparseness and fullness, which caused scrub to return incorrect results.
Fix the API so that we can tell the caller which of those three is the
current state.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:10 -07:00
Darrick J. Wong bd7e795108 xfs: refactor ->diff_two_keys callsites
Create wrapper functions around ->diff_two_keys so that we don't have to
remember what the return values mean, and adjust some of the code
comments to reflect the longtime code behavior.  We're going to
introduce more uses of ->diff_two_keys in the next patch, so reduce the
cognitive load for readers by doing this refactoring now.

Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:10 -07:00
Darrick J. Wong ee5fe8ff6d xfs: refactor converting btree irec to btree key
We keep doing these conversions to support btree queries, so refactor
this into a helper.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:09 -07:00
Darrick J. Wong 2bea8df0a5 xfs: always scrub record/key order of interior records
In commit d47fef9342, we removed the firstrec and firstkey fields of
struct xchk_btree because Christoph thought they were unnecessary
because we could use the record index in the btree cursor.  This is
incorrect because bc_ptrs (now bc_levels[].ptr) tracks the cursor
position within a specific btree block, not within the entire level.

The end result is that scrub no longer detects situations where the
rightmost record of a block is identical to the leftmost record of that
block's right sibling.  Fix this regression by reintroducing record
validity booleans so that order checking skips *only* the leftmost
record/key in each level.

Fixes: d47fef9342 ("xfs: don't track firstrec/firstkey separately in xchk_btree")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:09 -07:00
Darrick J. Wong c99f99fa3e xfs: check btree keys reflect the child block
When scrub is checking a non-root btree block, it should make sure that
the keys in the parent btree block accurately capture the keyspace that
the child block stores.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:08 -07:00
Darrick J. Wong 38384569a2 xfs: detect unwritten bit set in rmapbt node block keys
In the last patch, we changed the rmapbt code to remove the UNWRITTEN
bit when creating an rmapbt key from an rmapbt record, and we changed
the rmapbt key comparison code to start considering the ATTR and BMBT
flags during lookup.  This brought the behavior of the rmapbt
implementation in line with its specification.

However, there may exist filesystems that have the unwritten bit still
set in the rmapbt keys.  We should detect these situations and flag the
rmapbt as one that would benefit from optimization.  Eventually, online
repair will be able to do something in response to this.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:07 -07:00
Darrick J. Wong 08c987deca xfs: fix rm_offset flag handling in rmap keys
Keys for extent interval records in the reverse mapping btree are
supposed to be computed as follows:

(physical block, owner, fork, is_btree, offset)

This provides users the ability to look up a reverse mapping from a file
block mapping record -- start with the physical block; then if there are
multiple records for the same block, move on to the owner; then the
inode fork type; and so on to the file offset.

Unfortunately, the code that creates rmap lookup keys from rmap records
forgot to mask off the record attribute flags, leading to ondisk keys
that look like this:

(physical block, owner, fork, is_btree, unwritten state, offset)

Fortunately, this has all worked ok for the past six years because the
key comparison functions incorrectly ignore the fork/bmbt/unwritten
information that's encoded in the on-disk offset.  This means that
lookup comparisons are only done with:

(physical block, owner, offset)

Queries can (theoretically) return incorrect results because of this
omission.  On consistent filesystems this isn't an issue because xattr
and bmbt blocks cannot be shared and hence the comparisons succeed
purely on the contents of the rm_startblock field.  For the one case
where we support sharing (written data fork blocks) all flag bits are
zero, so the omission in the comparison has no ill effects.

Unfortunately, this bug prevents scrub from detecting incorrect fork and
bmbt flag bits in the rmap btree, so we really do need to fix the
compare code.  Old filesystems with the unwritten bit erroneously set in
the rmap key struct will work fine on new kernels since we still ignore
the unwritten bit.  New filesystems on older kernels will work fine
since the old kernels never paid attention to the unwritten bit.

A previous version of this patch forgot to keep the (un)written state
flag masked during the comparison and caused a major regression in
5.9.x since unwritten extent conversion can update an rmap record
without requiring key updates.

Note that blocks cannot go directly from data fork to attr fork without
being deallocated and reallocated, nor can they be added to or removed
from a bmbt without a free/alloc cycle, so this should not cause any
regressions.

Found by fuzzing keys[1].attrfork = ones on xfs/371.

Fixes: 4b8ed67794 ("xfs: add rmap btree operations")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:07 -07:00
Darrick J. Wong de1a9ce225 xfs: hoist inode record alignment checks from scrub
Move the inobt record alignment checks from xchk_iallocbt_rec into
xfs_inobt_check_irec so that they are applied everywhere.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:06 -07:00
Darrick J. Wong e774b2ea0b xfs: hoist rmap record flag checks from scrub
Move the rmap record flag checks from xchk_rmapbt_rec into
xfs_rmap_check_irec so that they are applied everywhere.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:06 -07:00
Darrick J. Wong 7d7d6d2fd0 xfs: hoist rmap record flag checks from scrub
Move the rmap record flag checks from xchk_rmapbt_rec into
xfs_rmap_check_irec so that they are applied everywhere.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:05 -07:00
Darrick J. Wong 6a3bd8fcf9 xfs: complain about bad file mapping records in the ondisk bmbt
Similar to what we've just done for the other btrees, create a function
to log corrupt bmbt records and call it whenever we encounter a bad
record in the ondisk btree.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:05 -07:00
Darrick J. Wong ee12eaaa43 xfs: complain about bad records in query_range helpers
For every btree type except for the bmbt, refactor the code that
complains about bad records into a helper and make the ->query_range
helpers call it so that corruptions found via that avenue are logged.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:04 -07:00
Darrick J. Wong 69010fe3ac xfs: standardize ondisk to incore conversion for bmap btrees
Fix all xfs_bmbt_disk_get_all callsites to call xfs_bmap_validate_extent
and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:04 -07:00
Darrick J. Wong c4e34172da xfs: standardize ondisk to incore conversion for rmap btrees
Create a xfs_rmap_check_irec function to detect corruption in btree
records.  Fix all xfs_rmap_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:03 -07:00
Darrick J. Wong 39ab26d59f xfs: return a failure address from xfs_rmap_irec_offset_unpack
Currently, xfs_rmap_irec_offset_unpack returns only 0 or -EFSCORRUPTED.
Change this function to return the code address of a failed conversion
in preparation for the next patch, which standardizes localized record
checking and reporting code.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:02 -07:00
Darrick J. Wong 2b30cc0bf0 xfs: standardize ondisk to incore conversion for refcount btrees
Create a xfs_refcount_check_irec function to detect corruption in btree
records.  Fix all xfs_refcount_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:02 -07:00
Darrick J. Wong 366a0b8d49 xfs: standardize ondisk to incore conversion for inode btrees
Create a xfs_inobt_check_irec function to detect corruption in btree
records.  Fix all xfs_inobt_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:01 -07:00
Darrick J. Wong 35e3b9a117 xfs: standardize ondisk to incore conversion for free space btrees
Create a xfs_alloc_btrec_to_irec function to convert an ondisk record to
an incore record, and a xfs_alloc_check_irec function to detect
corruption.  Replace all the open-coded logic with calls to the new
helpers and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:01 -07:00
Darrick J. Wong 88accf1722 xfs: scrub should use ECHRNG to signal that the drain is needed
In the previous patch, we added jump labels to the intent drain code so
that regular filesystem operations need not pay the price of checking
for someone (scrub) waiting on intents to drain from some part of the
filesystem when that someone isn't running.

However, I observed that xfs/285 now spends a lot more time pushing the
AIL from the inode btree scrubber than it used to.  This is because the
inobt scrubber will try push the AIL to try to get logged inode cores
written to the filesystem when it sees a weird discrepancy between the
ondisk inode and the inobt records.  This AIL push is triggered when the
setup function sees TRY_HARDER is set; and the requisite EDEADLOCK
return is initiated when the discrepancy is seen.

The solution to this performance slow down is to use a different result
code (ECHRNG) for scrub code to signal that it needs to wait for
deferred intent work items to drain out of some part of the filesystem.
When this happens, set a new scrub state flag (XCHK_NEED_DRAIN) so that
setup functions will activate the jump label.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:00 -07:00
Darrick J. Wong 466c525d6d xfs: minimize overhead of drain wakeups by using jump labels
To reduce the runtime overhead even further when online fsck isn't
running, use a static branch key to decide if we call wake_up on the
drain.  For compilers that support jump labels, the call to wake_up is
replaced by a nop sled when nobody is waiting for intents to drain.

From my initial microbenchmarking, every transition of the static key
between the on and off states takes about 22000ns to complete; this is
paid entirely by the xfs_scrub process.  When the static key is off
(which it should be when fsck isn't running), the nop sled adds an
overhead of approximately 0.36ns to runtime code.  The post-atomic
lockless waiter check adds about 0.03ns, which is basically free.

For the few compilers that don't support jump labels, runtime code pays
the cost of calling wake_up on an empty waitqueue, which was observed to
be about 30ns.  However, most architectures that have sufficient memory
and CPU capacity to run XFS also support jump labels, so this is not
much of a worry.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:59 -07:00
Darrick J. Wong 3f64c718d0 xfs: clean up scrub context if scrub setup returns -EDEADLOCK
It has been a longstanding convention that online scrub and repair
functions can return -EDEADLOCK to signal that they weren't able to
obtain some necessary resource.  When this happens, the scrub framework
is supposed to release all resources attached to the scrub context, set
the TRY_HARDER flag in the scrub context flags, and try again.  In this
context, individual scrub functions are supposed to take all the
resources they (incorrectly) speculated were not necessary.

We're about to make it so that the functions that lock and wait for a
filesystem AG can also return EDEADLOCK to signal that we need to try
again with the drain waiters enabled.  Therefore, refactor
xfs_scrub_metadata to support this behavior for ->setup() functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:59 -07:00
Darrick J. Wong d5c88131db xfs: allow queued AG intents to drain before scrubbing
When a writer thread executes a chain of log intent items, the AG header
buffer locks will cycle during a transaction roll to get from one intent
item to the next in a chain.  Although scrub takes all AG header buffer
locks, this isn't sufficient to guard against scrub checking an AG while
that writer thread is in the middle of finishing a chain because there's
no higher level locking primitive guarding allocation groups.

When there's a collision, cross-referencing between data structures
(e.g. rmapbt and refcountbt) yields false corruption events; if repair
is running, this results in incorrect repairs, which is catastrophic.

Fix this by adding to the perag structure the count of active intents
and make scrub wait until it has both AG header buffer locks and the
intent counter reaches zero.

One quirk of the drain code is that deferred bmap updates also bump and
drop the intent counter.  A fundamental decision made during the design
phase of the reverse mapping feature is that updates to the rmapbt
records are always made by the same code that updates the primary
metadata.  In other words, callers of bmapi functions expect that the
bmapi functions will queue deferred rmap updates.

Some parts of the reflink code queue deferred refcount (CUI) and bmap
(BUI) updates in the same head transaction, but the deferred work
manager completely finishes the CUI before the BUI work is started.  As
a result, the CUI drops the intent count long before the deferred rmap
(RUI) update even has a chance to bump the intent count.  The only way
to keep the intent count elevated between the CUI and RUI is for the BUI
to bump the counter until the RUI has been created.

A second quirk of the intent drain code is that deferred work items must
increment the intent counter as soon as the work item is added to the
transaction.  When a BUI completes and queues an RUI, the RUI must
increment the counter before the BUI decrements it.  The only way to
accomplish this is to require that the counter be bumped as soon as the
deferred work item is created in memory.

In the next patches we'll improve on this facility, but this patch
provides the basic functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:58 -07:00
Darrick J. Wong 9014890304 xfs: add a tracepoint to report incorrect extent refcounts
Add a new tracepoint so that I can see exactly what and where we failed
the refcount check.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:58 -07:00
Darrick J. Wong ecc73f8a58 xfs: update copyright years for scrub/ files
Update the copyright years in the scrub/ source code files.  This isn't
required, but it's helpful to remind myself just how long it's taken to
develop this feature.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:57 -07:00
Darrick J. Wong 739a2fe042 xfs: fix author and spdx headers on scrub/ files
Fix the spdx tags to match current practice, and update the author
contact information.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:56 -07:00
Darrick J. Wong 9b2e5a234c xfs: create traced helper to get extra perag references
There are a few places in the XFS codebase where a caller has either an
active or a passive reference to a perag structure and wants to give
a passive reference to some other piece of code.  Btree cursor creation
and inode walks are good examples of this.  Replace the open-coded logic
with a helper to do this.

The new function adds a few safeguards -- it checks that there's at
least one reference to the perag structure passed in, and it records the
refcount bump in the ftrace information.  This makes it much easier to
debug perag refcounting problems.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:55 -07:00
Darrick J. Wong 00e7b3bac1 xfs: give xfs_refcount_intent its own perag reference
Give the xfs_refcount_intent a passive reference to the perag structure
data.  This reference will be used to enable scrub intent draining
functionality in subsequent patches.  Any space being modified by a
refcount intent is already allocated, so we need to be able to operate
even if the AG is being shrunk or offlined.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:55 -07:00
Darrick J. Wong c13418e8eb xfs: give xfs_rmap_intent its own perag reference
Give the xfs_rmap_intent a passive reference to the perag structure
data.  This reference will be used to enable scrub intent draining
functionality in subsequent patches.  The space we're (reverse) mapping
is already allocated, so we need to be able to operate even if the AG is
being shrunk or offlined.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:54 -07:00
Darrick J. Wong f6b384631e xfs: give xfs_extfree_intent its own perag reference
Give the xfs_extfree_intent an passive reference to the perag structure
data.  This reference will be used to enable scrub intent draining
functionality in subsequent patches.  The space being freed must already
be allocated, so we need to able to run even if the AG is being offlined
or shrunk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:54 -07:00
Darrick J. Wong b2ccab3199 xfs: pass per-ag references to xfs_free_extent
Pass a reference to the per-AG structure to xfs_free_extent.  Most
callers already have one, so we can eliminate unnecessary lookups.  The
one exception to this is the EFI code, which the next patch will fix.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:53 -07:00
Darrick J. Wong 774a99b47b xfs: give xfs_bmap_intent its own perag reference
Give the xfs_bmap_intent an active reference to the perag structure
data.  This reference will be used to enable scrub intent draining
functionality in subsequent patches.  Later, shrink will use these
passive references to know if an AG is quiesced or not.

The reason why we take a passive ref for a file mapping operation is
simple: we're committing to some sort of action involving space in an
AG, so we want to indicate our interest in that AG.  The space is
already allocated, so we need to be able to operate on AGs that are
offline or being shrunk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:53 -07:00
Linus Torvalds cdc9718d5e two cifs/smb3 client fixes, one for stable
-----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE6fsu8pdIjtWE/DpLiiy9cAdyT1EFAmQx+FEACgkQiiy9cAdy
 T1FlAwwAwWXT25SD5AZBQdNNT/5GfnxYSqtO9p1TnE/ZSVEuujFCu0K4Ciw3njuS
 GtsrIfUkwYRvBNCIN+eqaNff1x3By3eHIVcZRRxidRc0qwQwsKIohMZHtbeXen7O
 IjJX/b7zJHIrzRSpntjMxe4gwlrkSrp4BMQmG6Y7GxwC+MLHxM4Gglifh/yxmMBX
 OqauYGl5oyJ6NzkzZ6fb/70OSWFmEKjXwzpa8SGipmm7udRNeau9m0ObTf2lc9yq
 i2/okR+H0PINHJLEy4HFt4KkQKiRBZSy0C2E9nO3r0C3IoCuD1W4ZY9BiJRg+xXS
 QYjPUVNFG7+aW/JsYUr6KeaDmGrw4PR2pttv7zj6tbANHq0FAOgsrYtNpwfkDaPR
 f9l0kRe75JNQIwtRDGUKY/iNbpgFKzuYojl7I7zVAYpQhQFswhXueQkQ+Nb9TUeq
 L63Olom0cQoeBA296T45li5suuUP1YmgUZlt2/X+a3PrYBU72aFukaShfkwde9gs
 kSUvF1rU
 =2VdA
 -----END PGP SIGNATURE-----

Merge tag '6.3-rc5-smb3-cifs-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs client fixes from Steve French:
 "Two cifs/smb3 client fixes, one for stable:

   - double lock fix for a cifs/smb1 reconnect path

   - DFS prefixpath fix for reconnect when server moved"

* tag '6.3-rc5-smb3-cifs-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: double lock in cifs_reconnect_tcon()
  cifs: sanitize paths in cifs_update_super_prepath.
2023-04-08 18:37:45 -07:00
Linus Torvalds 6fda0bb806 28 hotfixes.
23 are cc:stable and the other 5 address issues which were introduced
 during this merge cycle.
 
 20 are for MM and the remainder are for other subsystems.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZDCmIAAKCRDdBJ7gKXxA
 jhZuAQDn8ErAotUpLn1Pq6WU1liPenGoraBo/a2ubpOjguSINwD+J7L85vgVmA78
 YzoKHObW18yBW7JSzpWZ2zw8q2gLQwQ=
 =a1n7
 -----END PGP SIGNATURE-----

Merge tag 'mm-hotfixes-stable-2023-04-07-16-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM fixes from Andrew Morton:
 "28 hotfixes.

  23 are cc:stable and the other five address issues which were
  introduced during this merge cycle.

  20 are for MM and the remainder are for other subsystems"

* tag 'mm-hotfixes-stable-2023-04-07-16-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (28 commits)
  maple_tree: fix a potential concurrency bug in RCU mode
  maple_tree: fix get wrong data_end in mtree_lookup_walk()
  mm/swap: fix swap_info_struct race between swapoff and get_swap_pages()
  nilfs2: fix sysfs interface lifetime
  mm: take a page reference when removing device exclusive entries
  mm: vmalloc: avoid warn_alloc noise caused by fatal signal
  nilfs2: initialize "struct nilfs_binfo_dat"->bi_pad field
  nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()
  zsmalloc: document freeable stats
  zsmalloc: document new fullness grouping
  fsdax: force clear dirty mark if CoW
  mm/hugetlb: fix uffd wr-protection for CoW optimization path
  mm: enable maple tree RCU mode by default
  maple_tree: add RCU lock checking to rcu callback functions
  maple_tree: add smp_rmb() to dead node detection
  maple_tree: fix write memory barrier of nodes once dead for RCU mode
  maple_tree: remove extra smp_wmb() from mas_dead_leaves()
  maple_tree: fix freeing of nodes in rcu mode
  maple_tree: detect dead nodes in mas_start()
  maple_tree: be more cautious about dead nodes
  ...
2023-04-08 10:51:12 -07:00