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In commit d658e, we tried to improve the robustnes of xchk_get_inode in
the face of EINVAL returns from iget by calling xfs_imap to see if the
inobt itself thinks that the inode is allocated. Unfortunately, that
commit didn't consider the possibility that the inode gets allocated
after iget but before imap. In this case, the imap call will succeed,
but we turn that into a corruption error and tell userspace the inode is
corrupt.
Avoid this false corruption report by grabbing the AGI header and
retrying the iget before calling imap. If the iget succeeds, we can
proceed with the usual scrub-by-handle code. Fix all the incorrect
comments too, since unreadable/corrupt inodes no longer result in EINVAL
returns.
Fixes: d658e72b4a09 ("xfs: distinguish between corrupt inode and invalid inum in xfs_scrub_get_inode")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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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>
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Metadata files (e.g. realtime bitmaps and quota files) do not show up in
the bulkstat output, which means that scrub-by-handle does not work;
they can only be checked through a specific scrub type. Therefore, each
scrub type calls xchk_metadata_inode_forks to check the metadata for
whatever's in the file.
Unfortunately, that function doesn't actually check the inode record
itself. Refactor the function a bit to make that happen.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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We can handle files that are exactly s_maxbytes bytes long; we just
can't handle anything larger than that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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).
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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We keep doing these conversions to support btree queries, so refactor
this into a helper.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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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 were
generally missing the "in between" case and returning 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>
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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>
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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.
However, the key comparison functions incorrectly remove the fork/bmbt
information that's encoded in the on-disk offset. This means that
lookup comparisons are only done with:
(physical block, owner, offset)
This means that queries can return incorrect results. On consistent
filesystems this isn't an issue because bmbt blocks and blocks mapped to
an attr fork cannot be shared, but this prevents us from detecting
incorrect fork and bmbt flag bits in the rmap btree.
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: 4b8ed67794fe ("xfs: add rmap btree operations")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Prior to calling xfs_refcount_adjust_extents, we trimmed agbno/aglen
such that the end of the range would not be in the middle of the record.
If this is no longer the case, something is seriously wrong with the
btree. Bail out with a corruption error.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If we're in the middle of a deferred refcount operation and decide to
roll the transaction to avoid overflowing the transaction space, we need
to check the new agbno/aglen parameters that we're about to record in
the new intent. Specifically, we need to check that the new extent is
completely within the filesystem, and that continuation does not put us
into a different AG.
This should never happen, but if the keys of a node block are wrong, the
refcount btree lookups performed during the adjust operation (and
resumptions therein) can point us to the wrong record blocks. The
refcount domain should prevent most of this, but this is a convenient
place to double-check that everything is still ok.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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We've been (ab)using XFS_REFC_COW_START as both an integer quantity and
a bit flag, even though it's *only* a bit flag. Rename the variable to
reflect its nature and update the cast target since we're not supposed
to be comparing it to xfs_agblock_t now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Just prior to committing the reflink code into upstream, the xfs
maintainer at the time requested that I find a way to shard the refcount
records into two domains -- one for records tracking shared extents, and
a second for tracking CoW staging extents. The idea here was to
minimize mount time CoW reclamation by pushing all the CoW records to
the right edge of the keyspace, and it was accomplished by setting the
upper bit in rc_startblock. We don't allow AGs to have more than 2^31
blocks, so the bit was free.
Unfortunately, this was a very late addition to the codebase, so most of
the refcount record processing code still treats rc_startblock as a u32
and pays no attention to whether or not the upper bit (the cow flag) is
set. This is a weakness is theoretically exploitable, since we're not
fully validating the incoming metadata records.
Fuzzing demonstrates practical exploits of this weakness. If the cow
flag of a node block key record is corrupted, a lookup operation can go
to the wrong record block and start returning records from the wrong
cow/shared domain. This causes the math to go all wrong (since cow
domain is still implicit in the upper bit of rc_startblock) and we can
crash the kernel by tricking xfs into jumping into a nonexistent AG and
tripping over xfs_perag_get(mp, <nonexistent AG>) returning NULL.
To fix this, start tracking the domain as an explicit part of struct
xfs_refcount_irec, adjust all refcount functions to check the domain
of a returned record, and alter the function definitions to accept them
where necessary.
Found by fuzzing keys[2].cowflag = add in xfs/464.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Consolidate the open-coded xfs_refcount_irec fields into an actual
struct and use the existing _btrec_to_irec to decode the ondisk record.
This will reduce code churn in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Structure definitions for incore objects do not belong in the ondisk
format header. Move them to the incore types header where they belong.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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CoW forks only exist in memory, which means that they can only ever have
an incore extent tree. Hence they must always be FMT_EXTENTS, so check
this when we're scrubbing them.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Ensure that extents in an inode's CoW fork are not marked as shared in
the refcount btree.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Teach scrub to flag quota files containing unwritten extents.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Enhance the block map scrubber to check delayed allocation reservations.
Though there are no physical space allocations to check, we do need to
make sure that the range of file offsets being mapped are correct, and
to bump the lastoff cursor so that key order checking works correctly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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When scrub is checking file fork mappings against rmap records and
the rmap record starts before or ends after the bmap record, check the
adjacent bmap records to make sure that they're adjacent to the one
we're checking. This helps us to detect cases where the rmaps cover
territory that the bmaps do not.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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sparse complains that we can return an uninitialized error from this
function and that pag could be uninitialized. We know that there are no
zero-AG filesystems and hence we had to call xchk_bmap_check_ag_rmaps at
least once, so this is not actually possible, but I'm too worn out from
automated complaints from unsophisticated AIs so let's just fix this and
move on to more interesting problems, eh?
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Teach the summary count checker to count the number of free realtime
extents and compare that to the superblock copy.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If any part of the per-AG summary counter scan loop aborts without
collecting all of the data we need, the scrubber's observation data will
be invalid. Set the incomplete flag so that we abort the scrub without
reporting false corruptions. Document the data dependency here too.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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xfs_rtalloc_query_range scans the realtime bitmap file in order of
increasing file offset, so this caller can take ILOCK_SHARED on the rt
bitmap inode instead of ILOCK_EXCL. This isn't going to yield any
practical benefits at mount time, but we'd like to make the locking
usage consistent around xfs_rtalloc_query_all calls. Make all the
places we do this use the same xfs_ilock lockflags for consistency.
Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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It turns out that GETFSMAP and online fsck have had a bug for years due
to their use of ILOCK_SHARED to coordinate their linear scans of the
realtime bitmap. If the bitmap file's data fork happens to be in BTREE
format and the scan occurs immediately after mounting, the incore bmbt
will not be populated, leading to ASSERTs tripping over the incorrect
inode state. Because the bitmap scans always lock bitmap buffers in
increasing order of file offset, it is appropriate for these two callers
to take a shared ILOCK to improve scalability.
To fix this problem, load both data and attr fork state into memory when
mounting the realtime inodes. Realtime metadata files aren't supposed
to have an attr fork so the second step is likely a nop.
On most filesystems this is unlikely since the rtbitmap data fork is
usually in extents format, but it's possible to craft a filesystem that
will by fragmenting the free space in the data section and growfsing the
rt section.
Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap")
Also-Fixes: 46d9bfb5e706 ("xfs: cross-reference the realtime bitmap")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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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>
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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.
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>
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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>
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Currently, the intent draining code uses a per-AG atomic counter to keep
track of how many writer threads are currently or going to start
processing log intent items for that AG. This isn't particularly
efficient, since every counter update will dirty the cacheline, and the
only code that cares about precise counter values is online scrub, which
shouldn't be running all that often.
Therefore, substitute the atomic_t for a per-cpu counter with a high
batch limit to avoid pingponging cache lines as long as possible. While
updates to per-cpu counters are slower in the single-thread case (on the
author's system, 12ns vs. 8ns), this quickly reverses itself if there
are a lot of CPUs queuing intent items.
Because percpu counter summation is slow, this change shifts most of the
performance impact to code that calls xfs_drain_wait, which means that
online fsck runs a little bit slower to minimize the overhead of regular
runtime code.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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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. This is a little stupid since transactions
can queue intents without taking buffer locks, but it's not the end of
the world for scrub to wait (in KILLABLE state) for those transactions.
In the next patch we'll improve on this facility, but this patch
provides the basic functionality.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If we tried to repair something but the repair failed with -EDEADLOCK or
-EAGAIN, that means that the repair function couldn't grab some resource
it needed and wants us to try again. If we try again (with TRY_HARDER)
but still can't do it, exit back to userspace, since xfs_scrub_metadata
requires xrep_attempt to return -EAGAIN.
This makes the return value diagnostics look less weird, and fixes a
wart that remains from very early in the repair implementation.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Repair functions will not return EAGAIN -- if they were not able to
obtain resources, they should return EDEADLOCK (like the rest of online
fsck) to signal that we need to grab all the resources and try again.
Hence we don't need to deal with this case except as a debugging
assertion.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If the scrub process is sent a fatal signal while we're checking dquots,
the predicate for this will set the error code to -EINTR. Don't then
squash that into -ECANCELED, because the wrong errno turns up in the
trace output.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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If the program calling online fsck is terminated with a fatal signal,
bail out to userspace by returning EINTR, not EAGAIN. EAGAIN is used by
scrubbers to indicate that we should try again with more resources
locked, and not to indicate that the operation was cancelled. The
miswiring is mostly harmless, but it shows up in the trace data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Convert all the online scrub code to use the Linux slab allocator
functions directly instead of going through the kmem wrappers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Memory allocation usage is the same throughout online fsck -- we want
kernel memory, we have to be able to back out if we can't allocate
memory, and we don't want to spray dmesg with memory allocation failure
reports. Standardize the GFP flag usage and document these requirements.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Teach the AGFL repair function to check each block of the proposed AGFL
against the rmap btree. If the rmapbt finds any mappings that are not
OWN_AG, strike that block from the list.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Currently, the only way to lock an allocation group is to hold the AGI
and AGF buffers. If repair needs to roll the transaction while
repairing some AG metadata, it maintains that lock by holding the two
buffers across the transaction roll and joins them afterwards.
However, repair is not the same as the other parts of XFS that employ
this bhold/bjoin sequence, because it's possible that the AGI or AGF
buffers are not actually dirty before the roll. In this case, the
buffer log item can detach from the buffer, which means that we have to
re-set the buffer type in the bli after joining the buffer to the new
transaction so that log recovery will know what to do if the fs fails.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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While scrubbing an allocation group, we don't need to hold the AGFL
buffer as part of the scrub context. All that is necessary to lock an
AG is to hold the AGI and AGF buffers, so fix all the existing users of
the AGFL buffer to grab them only when necessary.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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While running the online fsck test suite, I noticed the following
assertion in the kernel log (edited for brevity):
XFS: Assertion failed: 0, file: fs/xfs/xfs_health.c, line: 571
------------[ cut here ]------------
WARNING: CPU: 3 PID: 11667 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 3 PID: 11667 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Call Trace:
<TASK>
xfs_dir2_isblock+0xcc/0xe0
xchk_directory_blocks+0xc7/0x420
xchk_directory+0x53/0xb0
xfs_scrub_metadata+0x2b6/0x6b0
xfs_scrubv_metadata+0x35e/0x4d0
xfs_ioc_scrubv_metadata+0x111/0x160
xfs_file_ioctl+0x4ec/0xef0
__x64_sys_ioctl+0x82/0xa0
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
This assertion triggers in xfs_dirattr_mark_sick when the caller passes
in a whichfork value that is neither of XFS_{DATA,ATTR}_FORK. The cause
of this is that xchk_directory_blocks only partially initializes the
xfs_da_args structure that is passed to xfs_dir2_isblock. If the data
fork is not correct, the XFS_IS_CORRUPT clause will trigger. My
development branch reports this failure to the health monitoring
subsystem, which accesses the uninitialized args->whichfork field,
leading the the assertion tripping. We really shouldn't be passing
random stack contents around, so the solution here is to force the
compiler to zero-initialize the struct.
Found by fuzzing u3.bmx[0].blockcount = middlebit on xfs/1554.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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KASAN reported a UAF bug when I was running xfs/235:
BUG: KASAN: use-after-free in xlog_recover_process_intents+0xa77/0xae0 [xfs]
Read of size 8 at addr ffff88804391b360 by task mount/5680
CPU: 2 PID: 5680 Comm: mount Not tainted 6.0.0-xfsx #6.0.0 77e7b52a4943a975441e5ac90a5ad7748b7867f6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report.cold+0x2cc/0x682
kasan_report+0xa3/0x120
xlog_recover_process_intents+0xa77/0xae0 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xlog_recover_finish+0x7d/0x970 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_log_mount_finish+0x2d7/0x5d0 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_mountfs+0x11d4/0x1d10 [xfs fb841c7180aad3f8359438576e27867f5795667e]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs fb841c7180aad3f8359438576e27867f5795667e]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7ff5bc069eae
Code: 48 8b 0d 85 1f 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 52 1f 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe433fd448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff5bc069eae
RDX: 00005575d7213290 RSI: 00005575d72132d0 RDI: 00005575d72132b0
RBP: 00005575d7212fd0 R08: 00005575d7213230 R09: 00005575d7213fe0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00005575d7213290 R14: 00005575d72132b0 R15: 00005575d7212fd0
</TASK>
Allocated by task 5680:
kasan_save_stack+0x1e/0x40
__kasan_slab_alloc+0x66/0x80
kmem_cache_alloc+0x152/0x320
xfs_rui_init+0x17a/0x1b0 [xfs]
xlog_recover_rui_commit_pass2+0xb9/0x2e0 [xfs]
xlog_recover_items_pass2+0xe9/0x220 [xfs]
xlog_recover_commit_trans+0x673/0x900 [xfs]
xlog_recovery_process_trans+0xbe/0x130 [xfs]
xlog_recover_process_data+0x103/0x2a0 [xfs]
xlog_do_recovery_pass+0x548/0xc60 [xfs]
xlog_do_log_recovery+0x62/0xc0 [xfs]
xlog_do_recover+0x73/0x480 [xfs]
xlog_recover+0x229/0x460 [xfs]
xfs_log_mount+0x284/0x640 [xfs]
xfs_mountfs+0xf8b/0x1d10 [xfs]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 5680:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x30
____kasan_slab_free+0x144/0x1b0
slab_free_freelist_hook+0xab/0x180
kmem_cache_free+0x1f1/0x410
xfs_rud_item_release+0x33/0x80 [xfs]
xfs_trans_free_items+0xc3/0x220 [xfs]
xfs_trans_cancel+0x1fa/0x590 [xfs]
xfs_rui_item_recover+0x913/0xd60 [xfs]
xlog_recover_process_intents+0x24e/0xae0 [xfs]
xlog_recover_finish+0x7d/0x970 [xfs]
xfs_log_mount_finish+0x2d7/0x5d0 [xfs]
xfs_mountfs+0x11d4/0x1d10 [xfs]
xfs_fs_fill_super+0x13d5/0x1a80 [xfs]
get_tree_bdev+0x3da/0x6e0
vfs_get_tree+0x7d/0x240
path_mount+0xdd3/0x17d0
__x64_sys_mount+0x1fa/0x270
do_syscall_64+0x2b/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The buggy address belongs to the object at ffff88804391b300
which belongs to the cache xfs_rui_item of size 688
The buggy address is located 96 bytes inside of
688-byte region [ffff88804391b300, ffff88804391b5b0)
The buggy address belongs to the physical page:
page:ffffea00010e4600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888043919320 pfn:0x43918
head:ffffea00010e4600 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4fff80000010200(slab|head|node=1|zone=1|lastcpupid=0xfff)
raw: 04fff80000010200 0000000000000000 dead000000000122 ffff88807f0eadc0
raw: ffff888043919320 0000000080140010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88804391b200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804391b280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804391b300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88804391b380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804391b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
The test fuzzes an rmap btree block and starts writer threads to induce
a filesystem shutdown on the corrupt block. When the filesystem is
remounted, recovery will try to replay the committed rmap intent item,
but the corruption problem causes the recovery transaction to fail.
Cancelling the transaction frees the RUD, which frees the RUI that we
recovered.
When we return to xlog_recover_process_intents, @lip is now a dangling
pointer, and we cannot use it to find the iop_recover method for the
tracepoint. Hence we must store the item ops before calling
->iop_recover if we want to give it to the tracepoint so that the trace
data will tell us exactly which intent item failed.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
|
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Let me count the ways in which I'd screwed up:
* when emitting a page, handling of gaps in coredump should happen
before fetching the current file position.
* fix for a problem that occurs on rather uncommon setups (and hadn't
been observed in the wild) had been sent very late in the cycle.
* ... with badly insufficient testing, introducing an easily
reproducible breakage. Without giving it time to soak in -next.
Fucked-up-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: "J. R. Okajima" <hooanon05g@gmail.com>
Tested-by: "J. R. Okajima" <hooanon05g@gmail.com>
Fixes: 06bbaa6dc53c "[coredump] don't use __kernel_write() on kmap_local_page()"
Cc: stable@kernel.org # v6.0-only
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Add a new tracepoint so we can see what mapping the filesystem returns
to writeback a dirty page.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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