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1073927 commits

Author SHA1 Message Date
Dave Chinner
919edbadeb xfs: drop async cache flushes from CIL commits.
Jan Kara reported a performance regression in dbench that he
bisected down to commit bad77c375e ("xfs: CIL checkpoint
flushes caches unconditionally").

Whilst developing the journal flush/fua optimisations this cache was
part of, it appeared to made a significant difference to
performance. However, now that this patchset has settled and all the
correctness issues fixed, there does not appear to be any
significant performance benefit to asynchronous cache flushes.

In fact, the opposite is true on some storage types and workloads,
where additional cache flushes that can occur from fsync heavy
workloads have measurable and significant impact on overall
throughput.

Local dbench testing shows little difference on dbench runs with
sync vs async cache flushes on either fast or slow SSD storage, and
no difference in streaming concurrent async transaction workloads
like fs-mark.

Fast NVME storage.

From `dbench -t 30`, CIL scale:

clients		async			sync
		BW	Latency		BW	Latency
1		 935.18   0.855		 915.64   0.903
8		2404.51   6.873		2341.77   6.511
16		3003.42   6.460		2931.57   6.529
32		3697.23   7.939		3596.28   7.894
128		7237.43  15.495		7217.74  11.588
512		5079.24  90.587		5167.08  95.822

fsmark, 32 threads, create w/ 64 byte xattr w/32k logbsize

	create		chown		unlink
async   1m41s		1m16s		2m03s
sync	1m40s		1m19s		1m54s

Slower SATA SSD storage:

From `dbench -t 30`, CIL scale:

clients		async			sync
		BW	Latency		BW	Latency
1		  78.59  15.792		  83.78  10.729
8		 367.88  92.067		 404.63  59.943
16		 564.51  72.524		 602.71  76.089
32		 831.66 105.984		 870.26 110.482
128		1659.76 102.969		1624.73  91.356
512		2135.91 223.054		2603.07 161.160

fsmark, 16 threads, create w/32k logbsize

	create		unlink
async   5m06s		4m15s
sync	5m00s		4m22s

And on Jan's test machine:

                   5.18-rc8-vanilla       5.18-rc8-patched
Amean     1        71.22 (   0.00%)       64.94 *   8.81%*
Amean     2        93.03 (   0.00%)       84.80 *   8.85%*
Amean     4       150.54 (   0.00%)      137.51 *   8.66%*
Amean     8       252.53 (   0.00%)      242.24 *   4.08%*
Amean     16      454.13 (   0.00%)      439.08 *   3.31%*
Amean     32      835.24 (   0.00%)      829.74 *   0.66%*
Amean     64     1740.59 (   0.00%)     1686.73 *   3.09%*

Performance and cache flush behaviour is restored to pre-regression
levels.

As such, we can now consider the async cache flush mechanism an
unnecessary exercise in premature optimisation and hence we can
now remove it and the infrastructure it requires completely.

Fixes: bad77c375e ("xfs: CIL checkpoint flushes caches unconditionally")
Reported-and-tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:02 -07:00
Dave Chinner
5652ef3170 xfs: shutdown during log recovery needs to mark the log shutdown
When a checkpoint writeback is run by log recovery, corruption
propagated from the log can result in writeback verifiers failing
and calling xfs_force_shutdown() from
xfs_buf_delwri_submit_buffers().

This results in the mount being marked as shutdown, but the log does
not get marked as shut down because:

        /*
         * If this happens during log recovery then we aren't using the runtime
         * log mechanisms yet so there's nothing to shut down.
         */
        if (!log || xlog_in_recovery(log))
                return false;

If there are other buffers that then fail (say due to detecting the
mount shutdown), they will now hang in xfs_do_force_shutdown()
waiting for the log to shut down like this:

  __schedule+0x30d/0x9e0
  schedule+0x55/0xd0
  xfs_do_force_shutdown+0x1cd/0x200
  ? init_wait_var_entry+0x50/0x50
  xfs_buf_ioend+0x47e/0x530
  __xfs_buf_submit+0xb0/0x240
  xfs_buf_delwri_submit_buffers+0xfe/0x270
  xfs_buf_delwri_submit+0x3a/0xc0
  xlog_do_recovery_pass+0x474/0x7b0
  ? do_raw_spin_unlock+0x30/0xb0
  xlog_do_log_recovery+0x91/0x140
  xlog_do_recover+0x38/0x1e0
  xlog_recover+0xdd/0x170
  xfs_log_mount+0x17e/0x2e0
  xfs_mountfs+0x457/0x930
  xfs_fs_fill_super+0x476/0x830

xlog_force_shutdown() always needs to mark the log as shut down,
regardless of whether recovery is in progress or not, so that
multiple calls to xfs_force_shutdown() during recovery don't end
up waiting for the log to be shut down like this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:02 -07:00
Dave Chinner
3c4cb76bce xfs: xfs_trans_commit() path must check for log shutdown
If a shut races with xfs_trans_commit() and we have shut down the
filesystem but not the log, we will still cancel the transaction.
This can result in aborting dirty log items instead of committing and
pinning them whilst the log is still running. Hence we can end up
with dirty, unlogged metadata that isn't in the AIL in memory that
can be flushed to disk via writeback clustering.

This was discovered from a g/388 trace where an inode log item was
having IO completed on it and it wasn't in the AIL, hence tripping
asserts xfs_ail_check(). Inode cluster writeback started long after
the filesystem shutdown started, and long after the transaction
containing the dirty inode was aborted and the log item marked
XFS_LI_ABORTED. The inode was seen as dirty and unpinned, so it
was flushed. IO completion tried to remove the inode from the AIL,
at which point stuff went bad:

 XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/xfs/xfs_fsops.c:500).  Shutting down filesystem.
 XFS: Assertion failed: in_ail, file: fs/xfs/xfs_trans_ail.c, line: 67
 XFS (pmem1): Please unmount the filesystem and rectify the problem(s)
 Workqueue: xfs-buf/pmem1 xfs_buf_ioend_work
 RIP: 0010:assfail+0x27/0x2d
 Call Trace:
  <TASK>
  xfs_ail_check+0xa8/0x180
  xfs_ail_delete_one+0x3b/0xf0
  xfs_buf_inode_iodone+0x329/0x3f0
  xfs_buf_ioend+0x1f8/0x530
  xfs_buf_ioend_work+0x15/0x20
  process_one_work+0x1ac/0x390
  worker_thread+0x56/0x3c0
  kthread+0xf6/0x120
  ret_from_fork+0x1f/0x30
  </TASK>

xfs_trans_commit() needs to check log state for shutdown, not mount
state. It cannot abort dirty log items while the log is still
running as dirty items must remained pinned in memory until they are
either committed to the journal or the log has shut down and they
can be safely tossed away. Hence if the log has not shut down, the
xfs_trans_commit() path must allow completed transactions to commit
to the CIL and pin the dirty items even if a mount shutdown has
started.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:01 -07:00
Dave Chinner
41e6362183 xfs: xfs_do_force_shutdown needs to block racing shutdowns
When we call xfs_forced_shutdown(), the caller often expects the
filesystem to be completely shut down when it returns. However,
if we have racing xfs_forced_shutdown() calls, the first caller sets
the mount shutdown flag then goes to shutdown the log. The second
caller sees the mount shutdown flag and returns immediately - it
does not wait for the log to be shut down.

Unfortunately, xfs_forced_shutdown() is used in some places that
expect it to completely shut down the filesystem before it returns
(e.g. xfs_trans_log_inode()). As such, returning before the log has
been shut down leaves us in a place where the transaction failed to
complete correctly but we still call xfs_trans_commit(). This
situation arises because xfs_trans_log_inode() does not return an
error and instead calls xfs_force_shutdown() to ensure that the
transaction being committed is aborted.

Unfortunately, we have a race condition where xfs_trans_commit()
needs to check xlog_is_shutdown() because it can't abort log items
before the log is shut down, but it needs to use xfs_is_shutdown()
because xfs_forced_shutdown() does not block waiting for the log to
shut down.

To fix this conundrum, first we make all calls to
xfs_forced_shutdown() block until the log is also shut down. This
means we can then safely use xfs_forced_shutdown() as a mechanism
that ensures the currently running transaction will be aborted by
xfs_trans_commit() regardless of the shutdown check it uses.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:01 -07:00
Dave Chinner
b5f17bec12 xfs: log shutdown triggers should only shut down the log
We've got a mess on our hands.

1. xfs_trans_commit() cannot cancel transactions because the mount is
shut down - that causes dirty, aborted, unlogged log items to sit
unpinned in memory and potentially get written to disk before the
log is shut down. Hence xfs_trans_commit() can only abort
transactions when xlog_is_shutdown() is true.

2. xfs_force_shutdown() is used in places to cause the current
modification to be aborted via xfs_trans_commit() because it may be
impractical or impossible to cancel the transaction directly, and
hence xfs_trans_commit() must cancel transactions when
xfs_is_shutdown() is true in this situation. But we can't do that
because of #1.

3. Log IO errors cause log shutdowns by calling xfs_force_shutdown()
to shut down the mount and then the log from log IO completion.

4. xfs_force_shutdown() can result in a log force being issued,
which has to wait for log IO completion before it will mark the log
as shut down. If #3 races with some other shutdown trigger that runs
a log force, we rely on xfs_force_shutdown() silently ignoring #3
and avoiding shutting down the log until the failed log force
completes.

5. To ensure #2 always works, we have to ensure that
xfs_force_shutdown() does not return until the the log is shut down.
But in the case of #4, this will result in a deadlock because the
log Io completion will block waiting for a log force to complete
which is blocked waiting for log IO to complete....

So the very first thing we have to do here to untangle this mess is
dissociate log shutdown triggers from mount shutdowns. We already
have xlog_forced_shutdown, which will atomically transistion to the
log a shutdown state. Due to internal asserts it cannot be called
multiple times, but was done simply because the only place that
could call it was xfs_do_force_shutdown() (i.e. the mount shutdown!)
and that could only call it once and once only.  So the first thing
we do is remove the asserts.

We then convert all the internal log shutdown triggers to call
xlog_force_shutdown() directly instead of xfs_force_shutdown(). This
allows the log shutdown triggers to shut down the log without
needing to care about mount based shutdown constraints. This means
we shut down the log independently of the mount and the mount may
not notice this until it's next attempt to read or modify metadata.
At that point (e.g. xfs_trans_commit()) it will see that the log is
shutdown, error out and shutdown the mount.

To ensure that all the unmount behaviours and asserts track
correctly as a result of a log shutdown, propagate the shutdown up
to the mount if it is not already set. This keeps the mount and log
state in sync, and saves a huge amount of hassle where code fails
because of a log shutdown but only checks for mount shutdowns and
hence ends up doing the wrong thing. Cleaning up that mess is
an exercise for another day.

This enables us to address the other problems noted above in
followup patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:01 -07:00
Dave Chinner
cd6f79d1fb xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks
Brian reported a null pointer dereference failure during unmount in
xfs/006. He tracked the problem down to the AIL being torn down
before a log shutdown had completed and removed all the items from
the AIL. The failure occurred in this path while unmount was
proceeding in another task:

 xfs_trans_ail_delete+0x102/0x130 [xfs]
 xfs_buf_item_done+0x22/0x30 [xfs]
 xfs_buf_ioend+0x73/0x4d0 [xfs]
 xfs_trans_committed_bulk+0x17e/0x2f0 [xfs]
 xlog_cil_committed+0x2a9/0x300 [xfs]
 xlog_cil_process_committed+0x69/0x80 [xfs]
 xlog_state_shutdown_callbacks+0xce/0xf0 [xfs]
 xlog_force_shutdown+0xdf/0x150 [xfs]
 xfs_do_force_shutdown+0x5f/0x150 [xfs]
 xlog_ioend_work+0x71/0x80 [xfs]
 process_one_work+0x1c5/0x390
 worker_thread+0x30/0x350
 kthread+0xd7/0x100
 ret_from_fork+0x1f/0x30

This is processing an EIO error to a log write, and it's
triggering a force shutdown. This causes the log to be shut down,
and then it is running attached iclog callbacks from the shutdown
context. That means the fs and log has already been marked as
xfs_is_shutdown/xlog_is_shutdown and so high level code will abort
(e.g. xfs_trans_commit(), xfs_log_force(), etc) with an error
because of shutdown.

The umount would have been blocked waiting for a log force
completion inside xfs_log_cover() -> xfs_sync_sb(). The first thing
for this situation to occur is for xfs_sync_sb() to exit without
waiting for the iclog buffer to be comitted to disk. The
above trace is the completion routine for the iclog buffer, and
it is shutting down the filesystem.

xlog_state_shutdown_callbacks() does this:

{
        struct xlog_in_core     *iclog;
        LIST_HEAD(cb_list);

        spin_lock(&log->l_icloglock);
        iclog = log->l_iclog;
        do {
                if (atomic_read(&iclog->ic_refcnt)) {
                        /* Reference holder will re-run iclog callbacks. */
                        continue;
                }
                list_splice_init(&iclog->ic_callbacks, &cb_list);
>>>>>>           wake_up_all(&iclog->ic_write_wait);
>>>>>>           wake_up_all(&iclog->ic_force_wait);
        } while ((iclog = iclog->ic_next) != log->l_iclog);

        wake_up_all(&log->l_flush_wait);
        spin_unlock(&log->l_icloglock);

>>>>>>  xlog_cil_process_committed(&cb_list);
}

This wakes any thread waiting on IO completion of the iclog (in this
case the umount log force) before shutdown processes all the pending
callbacks.  That means the xfs_sync_sb() waiting on a sync
transaction in xfs_log_force() on iclog->ic_force_wait will get
woken before the callbacks attached to that iclog are run. This
results in xfs_sync_sb() returning an error, and so unmount unblocks
and continues to run whilst the log shutdown is still in progress.

Normally this is just fine because the force waiter has nothing to
do with AIL operations. But in the case of this unmount path, the
log force waiter goes on to tear down the AIL because the log is now
shut down and so nothing ever blocks it again from the wait point in
xfs_log_cover().

Hence it's a race to see who gets to the AIL first - the unmount
code or xlog_cil_process_committed() killing the superblock buffer.

To fix this, we just have to change the order of processing in
xlog_state_shutdown_callbacks() to run the callbacks before it wakes
any task waiting on completion of the iclog.

Reported-by: Brian Foster <bfoster@redhat.com>
Fixes: aad7272a92 ("xfs: separate out log shutdown callback processing")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:00 -07:00
Dave Chinner
ab9c81ef32 xfs: shutdown in intent recovery has non-intent items in the AIL
generic/388 triggered a failure in RUI recovery due to a corrupted
btree record and the system then locked up hard due to a subsequent
assert failure while holding a spinlock cancelling intents:

 XFS (pmem1): Corruption of in-memory data (0x8) detected at xfs_do_force_shutdown+0x1a/0x20 (fs/xfs/xfs_trans.c:964).  Shutting down filesystem.
 XFS (pmem1): Please unmount the filesystem and rectify the problem(s)
 XFS: Assertion failed: !xlog_item_is_intent(lip), file: fs/xfs/xfs_log_recover.c, line: 2632
 Call Trace:
  <TASK>
  xlog_recover_cancel_intents.isra.0+0xd1/0x120
  xlog_recover_finish+0xb9/0x110
  xfs_log_mount_finish+0x15a/0x1e0
  xfs_mountfs+0x540/0x910
  xfs_fs_fill_super+0x476/0x830
  get_tree_bdev+0x171/0x270
  ? xfs_init_fs_context+0x1e0/0x1e0
  xfs_fs_get_tree+0x15/0x20
  vfs_get_tree+0x24/0xc0
  path_mount+0x304/0xba0
  ? putname+0x55/0x60
  __x64_sys_mount+0x108/0x140
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Essentially, there's dirty metadata in the AIL from intent recovery
transactions, so when we go to cancel the remaining intents we assume
that all objects after the first non-intent log item in the AIL are
not intents.

This is not true. Intent recovery can log new intents to continue
the operations the original intent could not complete in a single
transaction. The new intents are committed before they are deferred,
which means if the CIL commits in the background they will get
inserted into the AIL at the head.

Hence if we shut down the filesystem while processing intent
recovery, the AIL may have new intents active at the current head.
Hence this check:

                /*
                 * We're done when we see something other than an intent.
                 * There should be no intents left in the AIL now.
                 */
                if (!xlog_item_is_intent(lip)) {
#ifdef DEBUG
                        for (; lip; lip = xfs_trans_ail_cursor_next(ailp, &cur))
                                ASSERT(!xlog_item_is_intent(lip));
#endif
                        break;
                }

in both xlog_recover_process_intents() and
log_recover_cancel_intents() is simply not valid. It was valid back
when we only had EFI/EFD intents and didn't chain intents, but it
hasn't been valid ever since intent recovery could create and commit
new intents.

Given that crashing the mount task like this pretty much prevents
diagnosing what went wrong that lead to the initial failure that
triggered intent cancellation, just remove the checks altogether.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:22:00 -07:00
Dave Chinner
d2d7c04735 xfs: aborting inodes on shutdown may need buffer lock
Most buffer io list operations are run with the bp->b_lock held, but
xfs_iflush_abort() can be called without the buffer lock being held
resulting in inodes being removed from the buffer list while other
list operations are occurring. This causes problems with corrupted
bp->b_io_list inode lists during filesystem shutdown, leading to
traversals that never end, double removals from the AIL, etc.

Fix this by passing the buffer to xfs_iflush_abort() if we have
it locked. If the inode is attached to the buffer, we're going to
have to remove it from the buffer list and we'd have to get the
buffer off the inode log item to do that anyway.

If we don't have a buffer passed in (e.g. from xfs_reclaim_inode())
then we can determine if the inode has a log item and if it is
attached to a buffer before we do anything else. If it does have an
attached buffer, we can lock it safely (because the inode has a
reference to it) and then perform the inode abort.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-29 18:21:59 -07:00
Darrick J. Wong
85bcfa26f9 xfs: don't report reserved bnobt space as available
On a modern filesystem, we don't allow userspace to allocate blocks for
data storage from the per-AG space reservations, the user-controlled
reservation pool that prevents ENOSPC in the middle of internal
operations, or the internal per-AG set-aside that prevents unwanted
filesystem shutdowns due to ENOSPC during a bmap btree split.

Since we now consider freespace btree blocks as unavailable for
allocation for data storage, we shouldn't report those blocks via statfs
either.  This makes the numbers that we return via the statfs f_bavail
and f_bfree fields a more conservative estimate of actual free space.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28 08:39:10 -07:00
Darrick J. Wong
82be38bcf8 xfs: fix overfilling of reserve pool
Due to cycling of m_sb_lock, it's possible for multiple callers of
xfs_reserve_blocks to race at changing the pool size, subtracting blocks
from fdblocks, and actually putting it in the pool.  The result of all
this is that we can overfill the reserve pool to hilarious levels.

xfs_mod_fdblocks, when called with a positive value, already knows how
to take freed blocks and either fill the reserve until it's full, or put
them in fdblocks.  Use that instead of setting m_resblks_avail directly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28 08:39:02 -07:00
Darrick J. Wong
0baa2657dc xfs: always succeed at setting the reserve pool size
Nowadays, xfs_mod_fdblocks will always choose to fill the reserve pool
with freed blocks before adding to fdblocks.  Therefore, we can change
the behavior of xfs_reserve_blocks slightly -- setting the target size
of the pool should always succeed, since a deficiency will eventually
be made up as blocks get freed.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28 08:38:56 -07:00
Darrick J. Wong
15f04fdc75 xfs: remove infinite loop when reserving free block pool
Infinite loops in kernel code are scary.  Calls to xfs_reserve_blocks
should be rare (people should just use the defaults!) so we really don't
need to try so hard.  Simplify the logic here by removing the infinite
loop.

Cc: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28 08:38:50 -07:00
Darrick J. Wong
c8c5682597 xfs: don't include bnobt blocks when reserving free block pool
xfs_reserve_blocks controls the size of the user-visible free space
reserve pool.  Given the difference between the current and requested
pool sizes, it will try to reserve free space from fdblocks.  However,
the amount requested from fdblocks is also constrained by the amount of
space that we think xfs_mod_fdblocks will give us.  If we forget to
subtract m_allocbt_blks before calling xfs_mod_fdblocks, it will will
return ENOSPC and we'll hang the kernel at mount due to the infinite
loop.

In commit fd43cf600c, we decided that xfs_mod_fdblocks should not hand
out the "free space" used by the free space btrees, because some portion
of the free space btrees hold in reserve space for future btree
expansion.  Unfortunately, xfs_reserve_blocks' estimation of the number
of blocks that it could request from xfs_mod_fdblocks was not updated to
include m_allocbt_blks, so if space is extremely low, the caller hangs.

Fix this by creating a function to estimate the number of blocks that
can be reserved from fdblocks, which needs to exclude the set-aside and
m_allocbt_blks.

Found by running xfs/306 (which formats a single-AG 20MB filesystem)
with an fstests configuration that specifies a 1k blocksize and a
specially crafted log size that will consume 7/8 of the space (17920
blocks, specifically) in that AG.

Cc: Brian Foster <bfoster@redhat.com>
Fixes: fd43cf600c ("xfs: set aside allocation btree blocks from block reservation")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-28 08:38:43 -07:00
Darrick J. Wong
93defd5a15 xfs: document the XFS_ALLOC_AGFL_RESERVE constant
Currently, we use this undocumented macro to encode the minimum number
of blocks needed to replenish a completely empty AGFL when an AG is
nearly full.  This has lead to confusion on the part of the maintainers,
so let's document what the value actually means, and move it to
xfs_alloc.c since it's not used outside of that module.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-21 13:57:45 -07:00
Dave Chinner
01728b44ef xfs: xfs_is_shutdown vs xlog_is_shutdown cage fight
I've been chasing a recent resurgence in generic/388 recovery
failure and/or corruption events. The events have largely been
uninitialised inode chunks being tripped over in log recovery
such as:

 XFS (pmem1): User initiated shutdown received.
 pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
 XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/xfs/xfs_fsops.c:500).  Shutting down filesystem.
 XFS (pmem1): Please unmount the filesystem and rectify the problem(s)
 XFS (pmem1): Unmounting Filesystem
 XFS (pmem1): Mounting V5 Filesystem
 XFS (pmem1): Starting recovery (logdev: internal)
 XFS (pmem1): bad inode magic/vsn daddr 8723584 #0 (magic=1818)
 XFS (pmem1): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x851c80 xfs_inode_buf_verify
 XFS (pmem1): Unmount and run xfs_repair
 XFS (pmem1): First 128 bytes of corrupted metadata buffer:
 00000000: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000010: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000020: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000030: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000040: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000050: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000060: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 00000070: 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18  ................
 XFS (pmem1): metadata I/O error in "xlog_recover_items_pass2+0x52/0xc0" at daddr 0x851c80 len 32 error 117
 XFS (pmem1): log mount/recovery failed: error -117
 XFS (pmem1): log mount failed

There have been isolated random other issues, too - xfs_repair fails
because it finds some corruption in symlink blocks, rmap
inconsistencies, etc - but they are nowhere near as common as the
uninitialised inode chunk failure.

The problem has clearly happened at runtime before recovery has run;
I can see the ICREATE log item in the log shortly before the
actively recovered range of the log. This means the ICREATE was
definitely created and written to the log, but for some reason the
tail of the log has been moved past the ordered buffer log item that
tracks INODE_ALLOC buffers and, supposedly, prevents the tail of the
log moving past the ICREATE log item before the inode chunk buffer
is written to disk.

Tracing the fsstress processes that are running when the filesystem
shut down immediately pin-pointed the problem:

user shutdown marks xfs_mount as shutdown

         godown-213341 [008]  6398.022871: console:              [ 6397.915392] XFS (pmem1): User initiated shutdown received.
.....

aild tries to push ordered inode cluster buffer

  xfsaild/pmem1-213314 [001]  6398.022974: xfs_buf_trylock:      dev 259:1 daddr 0x851c80 bbcount 0x20 hold 16 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_inode_item_push+0x8e
  xfsaild/pmem1-213314 [001]  6398.022976: xfs_ilock_nowait:     dev 259:1 ino 0x851c80 flags ILOCK_SHARED caller xfs_iflush_cluster+0xae

xfs_iflush_cluster() checks xfs_is_shutdown(), returns true,
calls xfs_iflush_abort() to kill writeback of the inode.
Inode is removed from AIL, drops cluster buffer reference.

  xfsaild/pmem1-213314 [001]  6398.022977: xfs_ail_delete:       dev 259:1 lip 0xffff88880247ed80 old lsn 7/20344 new lsn 7/21000 type XFS_LI_INODE flags IN_AIL
  xfsaild/pmem1-213314 [001]  6398.022978: xfs_buf_rele:         dev 259:1 daddr 0x851c80 bbcount 0x20 hold 17 pincount 0 lock 0 flags DONE|INODES|PAGES caller xfs_iflush_abort+0xd7

.....

All inodes on cluster buffer are aborted, then the cluster buffer
itself is aborted and removed from the AIL *without writeback*:

xfsaild/pmem1-213314 [001]  6398.023011: xfs_buf_error_relse:  dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_ioend_fail+0x33
   xfsaild/pmem1-213314 [001]  6398.023012: xfs_ail_delete:       dev 259:1 lip 0xffff8888053efde8 old lsn 7/20344 new lsn 7/20344 type XFS_LI_BUF flags IN_AIL

The inode buffer was at 7/20344 when it was removed from the AIL.

   xfsaild/pmem1-213314 [001]  6398.023012: xfs_buf_item_relse:   dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_done+0x31
   xfsaild/pmem1-213314 [001]  6398.023012: xfs_buf_rele:         dev 259:1 daddr 0x851c80 bbcount 0x20 hold 2 pincount 0 lock 0 flags ASYNC|DONE|STALE|INODES|PAGES caller xfs_buf_item_relse+0x39

.....

Userspace is still running, doing stuff. an fsstress process runs
syncfs() or sync() and we end up in sync_fs_one_sb() which issues
a log force. This pushes on the CIL:

        fsstress-213322 [001]  6398.024430: xfs_fs_sync_fs:       dev 259:1 m_features 0x20000000019ff6e9 opstate (clean|shutdown|inodegc|blockgc) s_flags 0x70810000 caller sync_fs_one_sb+0x26
        fsstress-213322 [001]  6398.024430: xfs_log_force:        dev 259:1 lsn 0x0 caller xfs_fs_sync_fs+0x82
        fsstress-213322 [001]  6398.024430: xfs_log_force:        dev 259:1 lsn 0x5f caller xfs_log_force+0x7c
           <...>-194402 [001]  6398.024467: kmem_alloc:           size 176 flags 0x14 caller xlog_cil_push_work+0x9f

And the CIL fills up iclogs with pending changes. This picks up
the current tail from the AIL:

           <...>-194402 [001]  6398.024497: xlog_iclog_get_space: dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x0 flags  caller xlog_write+0x149
           <...>-194402 [001]  6398.024498: xlog_iclog_switch:    dev 259:1 state XLOG_STATE_ACTIVE refcnt 1 offset 0 lsn 0x700005408 flags  caller xlog_state_get_iclog_space+0x37e
           <...>-194402 [001]  6398.024521: xlog_iclog_release:   dev 259:1 state XLOG_STATE_WANT_SYNC refcnt 1 offset 32256 lsn 0x700005408 flags  caller xlog_write+0x5f9
           <...>-194402 [001]  6398.024522: xfs_log_assign_tail_lsn: dev 259:1 new tail lsn 7/21000, old lsn 7/20344, last sync 7/21448

And it moves the tail of the log to 7/21000 from 7/20344. This
*moves the tail of the log beyond the ICREATE transaction* that was
at 7/20344 and pinned by the inode cluster buffer that was cancelled
above.

....

         godown-213341 [008]  6398.027005: xfs_force_shutdown:   dev 259:1 tag logerror flags log_io|force_umount file fs/xfs/xfs_fsops.c line_num 500
          godown-213341 [008]  6398.027022: console:              [ 6397.915406] pmem1: writeback error on inode 12621949, offset 1019904, sector 12968096
          godown-213341 [008]  6398.030551: console:              [ 6397.919546] XFS (pmem1): Log I/O Error (0x6) detected at xfs_fs_goingdown+0xa3/0xf0 (fs/

And finally the log itself is now shutdown, stopping all further
writes to the log. But this is too late to prevent the corruption
that moving the tail of the log forwards after we start cancelling
writeback causes.

The fundamental problem here is that we are using the wrong shutdown
checks for log items. We've long conflated mount shutdown with log
shutdown state, and I started separating that recently with the
atomic shutdown state changes in commit b36d4651e1 ("xfs: make
forced shutdown processing atomic"). The changes in that commit
series are directly responsible for being able to diagnose this
issue because it clearly separated mount shutdown from log shutdown.

Essentially, once we start cancelling writeback of log items and
removing them from the AIL because the filesystem is shut down, we
*cannot* update the journal because we may have cancelled the items
that pin the tail of the log. That moves the tail of the log
forwards without having written the metadata back, hence we have
corrupt in memory state and writing to the journal propagates that
to the on-disk state.

What commit b36d4651e1 makes clear is that log item state needs to
change relative to log shutdown, not mount shutdown. IOWs, anything
that aborts metadata writeback needs to check log shutdown state
because log items directly affect log consistency. Having them check
mount shutdown state introduces the above race condition where we
cancel metadata writeback before the log shuts down.

To fix this, this patch works through all log items and converts
shutdown checks to use xlog_is_shutdown() rather than
xfs_is_shutdown(), so that we don't start aborting metadata
writeback before we shut off journal writes.

AFAICT, this race condition is a zero day IO error handling bug in
XFS that dates back to the introduction of XLOG_IO_ERROR,
XLOG_STATE_IOERROR and XFS_FORCED_SHUTDOWN back in January 1997.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:50 -07:00
Dave Chinner
8eda872110 xfs: AIL should be log centric
The AIL operates purely on log items, so it is a log centric
subsystem. Divorce it from the xfs_mount and instead have it pass
around xlog pointers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Dave Chinner
d86142dd7c xfs: log items should have a xlog pointer, not a mount
Log items belong to the log, not the xfs_mount. Convert the mount
pointer in the log item to a xlog pointer in preparation for
upcoming log centric changes to the log items.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Dave Chinner
70447e0ad9 xfs: async CIL flushes need pending pushes to be made stable
When the AIL tries to flush the CIL, it relies on the CIL push
ending up on stable storage without having to wait for and
manipulate iclog state directly. However, if there is already a
pending CIL push when the AIL tries to flush the CIL, it won't set
the cil->xc_push_commit_stable flag and so the CIL push will not
actively flush the commit record iclog.

generic/530 when run on a single CPU test VM can trigger this fairly
reliably. This test exercises unlinked inode recovery, and can
result in inodes being pinned in memory by ongoing modifications to
the inode cluster buffer to record unlinked list modifications. As a
result, the first inode unlinked in a buffer can pin the tail of the
log whilst the inode cluster buffer is pinned by the current
checkpoint that has been pushed but isn't on stable storage because
because the cil->xc_push_commit_stable was not set. This results in
the log/AIL effectively deadlocking until something triggers the
commit record iclog to be pushed to stable storage (i.e. the
periodic log worker calling xfs_log_force()).

The fix is two-fold - first we should always set the
cil->xc_push_commit_stable when xlog_cil_flush() is called,
regardless of whether there is already a pending push or not.

Second, if the CIL is empty, we should trigger an iclog flush to
ensure that the iclogs of the last checkpoint have actually been
submitted to disk as that checkpoint may not have been run under
stable completion constraints.

Reported-and-tested-by: Matthew Wilcox <willy@infradead.org>
Fixes: 0020a190cf ("xfs: AIL needs asynchronous CIL forcing")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Dave Chinner
941fbdfd6d xfs: xfs_ail_push_all_sync() stalls when racing with updates
xfs_ail_push_all_sync() has a loop like this:

while max_ail_lsn {
	prepare_to_wait(ail_empty)
	target = max_ail_lsn
	wake_up(ail_task);
	schedule()
}

Which is designed to sleep until the AIL is emptied. When
xfs_ail_update_finish() moves the tail of the log, it does:

	if (list_empty(&ailp->ail_head))
		wake_up_all(&ailp->ail_empty);

So it will only wake up the sync push waiter when the AIL goes
empty. If, by the time the push waiter has woken, the AIL has more
in it, it will reset the target, wake the push task and go back to
sleep.

The problem here is that if the AIL is having items added to it
when xfs_ail_push_all_sync() is called, then they may get inserted
into the AIL at a LSN higher than the target LSN. At this point,
xfsaild_push() will see that the target is X, the item LSNs are
(X+N) and skip over them, hence never pushing the out.

The result of this the AIL will not get emptied by the AIL push
thread, hence xfs_ail_finish_update() will never see the AIL being
empty even if it moves the tail. Hence xfs_ail_push_all_sync() never
gets woken and hence cannot update the push target to capture the
items beyond the current target on the LSN.

This is a TOCTOU type of issue so the way to avoid it is to not
use the push target at all for sync pushes. We know that a sync push
is being requested by the fact the ail_empty wait queue is active,
hence the xfsaild can just set the target to max_ail_lsn on every
push that we see the wait queue active. Hence we no longer will
leave items on the AIL that are beyond the LSN sampled at the start
of a sync push.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Dave Chinner
dbd0f52993 xfs: check buffer pin state after locking in delwri_submit
AIL flushing can get stuck here:

[316649.005769] INFO: task xfsaild/pmem1:324525 blocked for more than 123 seconds.
[316649.007807]       Not tainted 5.17.0-rc6-dgc+ #975
[316649.009186] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[316649.011720] task:xfsaild/pmem1   state:D stack:14544 pid:324525 ppid:     2 flags:0x00004000
[316649.014112] Call Trace:
[316649.014841]  <TASK>
[316649.015492]  __schedule+0x30d/0x9e0
[316649.017745]  schedule+0x55/0xd0
[316649.018681]  io_schedule+0x4b/0x80
[316649.019683]  xfs_buf_wait_unpin+0x9e/0xf0
[316649.021850]  __xfs_buf_submit+0x14a/0x230
[316649.023033]  xfs_buf_delwri_submit_buffers+0x107/0x280
[316649.024511]  xfs_buf_delwri_submit_nowait+0x10/0x20
[316649.025931]  xfsaild+0x27e/0x9d0
[316649.028283]  kthread+0xf6/0x120
[316649.030602]  ret_from_fork+0x1f/0x30

in the situation where flushing gets preempted between the unpin
check and the buffer trylock under nowait conditions:

	blk_start_plug(&plug);
	list_for_each_entry_safe(bp, n, buffer_list, b_list) {
		if (!wait_list) {
			if (xfs_buf_ispinned(bp)) {
				pinned++;
				continue;
			}
Here >>>>>>
			if (!xfs_buf_trylock(bp))
				continue;

This means submission is stuck until something else triggers a log
force to unpin the buffer.

To get onto the delwri list to begin with, the buffer pin state has
already been checked, and hence it's relatively rare we get a race
between flushing and encountering a pinned buffer in delwri
submission to begin with. Further, to increase the pin count the
buffer has to be locked, so the only way we can hit this race
without failing the trylock is to be preempted between the pincount
check seeing zero and the trylock being run.

Hence to avoid this problem, just invert the order of trylock vs
pin check. We shouldn't hit that many pinned buffers here, so
optimising away the trylock for pinned buffers should not matter for
performance at all.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Dave Chinner
a9a4bc8c76 xfs: log worker needs to start before intent/unlink recovery
After 963 iterations of generic/530, it deadlocked during recovery
on a pinned inode cluster buffer like so:

XFS (pmem1): Starting recovery (logdev: internal)
INFO: task kworker/8:0:306037 blocked for more than 122 seconds.
      Not tainted 5.17.0-rc6-dgc+ #975
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/8:0     state:D stack:13024 pid:306037 ppid:     2 flags:0x00004000
Workqueue: xfs-inodegc/pmem1 xfs_inodegc_worker
Call Trace:
 <TASK>
 __schedule+0x30d/0x9e0
 schedule+0x55/0xd0
 schedule_timeout+0x114/0x160
 __down+0x99/0xf0
 down+0x5e/0x70
 xfs_buf_lock+0x36/0xf0
 xfs_buf_find+0x418/0x850
 xfs_buf_get_map+0x47/0x380
 xfs_buf_read_map+0x54/0x240
 xfs_trans_read_buf_map+0x1bd/0x490
 xfs_imap_to_bp+0x4f/0x70
 xfs_iunlink_map_ino+0x66/0xd0
 xfs_iunlink_map_prev.constprop.0+0x148/0x2f0
 xfs_iunlink_remove_inode+0xf2/0x1d0
 xfs_inactive_ifree+0x1a3/0x900
 xfs_inode_unlink+0xcc/0x210
 xfs_inodegc_worker+0x1ac/0x2f0
 process_one_work+0x1ac/0x390
 worker_thread+0x56/0x3c0
 kthread+0xf6/0x120
 ret_from_fork+0x1f/0x30
 </TASK>
task:mount           state:D stack:13248 pid:324509 ppid:324233 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x30d/0x9e0
 schedule+0x55/0xd0
 schedule_timeout+0x114/0x160
 __down+0x99/0xf0
 down+0x5e/0x70
 xfs_buf_lock+0x36/0xf0
 xfs_buf_find+0x418/0x850
 xfs_buf_get_map+0x47/0x380
 xfs_buf_read_map+0x54/0x240
 xfs_trans_read_buf_map+0x1bd/0x490
 xfs_imap_to_bp+0x4f/0x70
 xfs_iget+0x300/0xb40
 xlog_recover_process_one_iunlink+0x4c/0x170
 xlog_recover_process_iunlinks.isra.0+0xee/0x130
 xlog_recover_finish+0x57/0x110
 xfs_log_mount_finish+0xfc/0x1e0
 xfs_mountfs+0x540/0x910
 xfs_fs_fill_super+0x495/0x850
 get_tree_bdev+0x171/0x270
 xfs_fs_get_tree+0x15/0x20
 vfs_get_tree+0x24/0xc0
 path_mount+0x304/0xba0
 __x64_sys_mount+0x108/0x140
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
 </TASK>
task:xfsaild/pmem1   state:D stack:14544 pid:324525 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x30d/0x9e0
 schedule+0x55/0xd0
 io_schedule+0x4b/0x80
 xfs_buf_wait_unpin+0x9e/0xf0
 __xfs_buf_submit+0x14a/0x230
 xfs_buf_delwri_submit_buffers+0x107/0x280
 xfs_buf_delwri_submit_nowait+0x10/0x20
 xfsaild+0x27e/0x9d0
 kthread+0xf6/0x120
 ret_from_fork+0x1f/0x30

We have the mount process waiting on an inode cluster buffer read,
inodegc doing unlink waiting on the same inode cluster buffer, and
the AIL push thread blocked in writeback waiting for the inode
cluster buffer to become unpinned.

What has happened here is that the AIL push thread has raced with
the inodegc process modifying, committing and pinning the inode
cluster buffer here in xfs_buf_delwri_submit_buffers() here:

	blk_start_plug(&plug);
	list_for_each_entry_safe(bp, n, buffer_list, b_list) {
		if (!wait_list) {
			if (xfs_buf_ispinned(bp)) {
				pinned++;
				continue;
			}
Here >>>>>>
			if (!xfs_buf_trylock(bp))
				continue;

Basically, the AIL has found the buffer wasn't pinned and got the
lock without blocking, but then the buffer was pinned. This implies
the processing here was pre-empted between the pin check and the
lock, because the pin count can only be increased while holding the
buffer locked. Hence when it has gone to submit the IO, it has
blocked waiting for the buffer to be unpinned.

With all executing threads now waiting on the buffer to be unpinned,
we normally get out of situations like this via the background log
worker issuing a log force which will unpinned stuck buffers like
this. But at this point in recovery, we haven't started the log
worker. In fact, the first thing we do after processing intents and
unlinked inodes is *start the log worker*. IOWs, we start it too
late to have it break deadlocks like this.

Avoid this and any other similar deadlock vectors in intent and
unlinked inode recovery by starting the log worker before we recover
intents and unlinked inodes. This part of recovery runs as though
the filesystem is fully active, so we really should have the same
infrastructure running as we normally do at runtime.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Darrick J. Wong
744e6c8ada xfs: constify xfs_name_dotdot
The symbol xfs_name_dotdot is a global variable that the xfs codebase
uses here and there to look up directory dotdot entries.  Currently it's
a non-const variable, which means that it's a mutable global variable.
So far nobody's abused this to cause problems, but let's use the
compiler to enforce that.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-14 10:23:17 -07:00
Darrick J. Wong
996b2329b2 xfs: constify the name argument to various directory functions
Various directory functions do not modify their @name parameter,
so mark it const to make that clear.  This will enable us to mark
the global xfs_name_dotdot variable as const to prevent mischief.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-14 10:23:17 -07:00
Darrick J. Wong
41667260bc xfs: reserve quota for target dir expansion when renaming files
XFS does not reserve quota for directory expansion when renaming
children into a directory.  This means that we don't reject the
expansion with EDQUOT when we're at or near a hard limit, which means
that unprivileged userspace can use rename() to exceed quota.

Rename operations don't always expand the target directory, and we allow
a rename to proceed with no space reservation if we don't need to add a
block to the target directory to handle the addition.  Moreover, the
unlink operation on the source directory generally does not expand the
directory (you'd have to free a block and then cause a btree split) and
it's probably of little consequence to leave the corner case that
renaming a file out of a directory can increase its size.

As with link and unlink, there is a further bug in that we do not
trigger the blockgc workers to try to clear space when we're out of
quota.

Because rename is its own special tricky animal, we'll patch xfs_rename
directly to reserve quota to the rename transaction.  We'll leave
cleaning up the rest of xfs_rename for the metadata directory tree
patchset.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-14 10:23:17 -07:00
Darrick J. Wong
871b9316e7 xfs: reserve quota for dir expansion when linking/unlinking files
XFS does not reserve quota for directory expansion when linking or
unlinking children from a directory.  This means that we don't reject
the expansion with EDQUOT when we're at or near a hard limit, which
means that unprivileged userspace can use link()/unlink() to exceed
quota.

The fix for this is nuanced -- link operations don't always expand the
directory, and we allow a link to proceed with no space reservation if
we don't need to add a block to the directory to handle the addition.
Unlink operations generally do not expand the directory (you'd have to
free a block and then cause a btree split) and we can defer the
directory block freeing if there is no space reservation.

Moreover, there is a further bug in that we do not trigger the blockgc
workers to try to clear space when we're out of quota.

To fix both cases, create a new xfs_trans_alloc_dir function that
allocates the transaction, locks and joins the inodes, and reserves
quota for the directory.  If there isn't sufficient space or quota,
we'll switch the caller to reservationless mode.  This should prevent
quota usage overruns with the least restriction in functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-14 10:23:17 -07:00
Darrick J. Wong
dd3b015dd8 xfs: refactor user/group quota chown in xfs_setattr_nonsize
Combine if tests to reduce the indentation levels of the quota chown
calls in xfs_setattr_nonsize.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
2022-03-14 10:23:17 -07:00
Darrick J. Wong
e014f37db1 xfs: use setattr_copy to set vfs inode attributes
Filipe Manana pointed out that XFS' behavior w.r.t. setuid/setgid
revocation isn't consistent with btrfs[1] or ext4.  Those two
filesystems use the VFS function setattr_copy to convey certain
attributes from struct iattr into the VFS inode structure.

Andrey Zhadchenko reported[2] that XFS uses the wrong user namespace to
decide if it should clear setgid and setuid on a file attribute update.
This is a second symptom of the problem that Filipe noticed.

XFS, on the other hand, open-codes setattr_copy in xfs_setattr_mode,
xfs_setattr_nonsize, and xfs_setattr_time.  Regrettably, setattr_copy is
/not/ a simple copy function; it contains additional logic to clear the
setgid bit when setting the mode, and XFS' version no longer matches.

The VFS implements its own setuid/setgid stripping logic, which
establishes consistent behavior.  It's a tad unfortunate that it's
scattered across notify_change, should_remove_suid, and setattr_copy but
XFS should really follow the Linux VFS.  Adapt XFS to use the VFS
functions and get rid of the old functions.

[1] https://lore.kernel.org/fstests/CAL3q7H47iNQ=Wmk83WcGB-KBJVOEtR9+qGczzCeXJ9Y2KCV25Q@mail.gmail.com/
[2] https://lore.kernel.org/linux-xfs/20220221182218.748084-1-andrey.zhadchenko@virtuozzo.com/

Fixes: 7fa294c899 ("userns: Allow chown and setgid preservation")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
2022-03-14 10:23:16 -07:00
Darrick J. Wong
eba0549bc7 xfs: don't generate selinux audit messages for capability testing
There are a few places where we test the current process' capability set
to decide if we're going to be more or less generous with resource
acquisition for a system call.  If the process doesn't have the
capability, we can continue the call, albeit in a degraded mode.

These are /not/ the actual security decisions, so it's not proper to use
capable(), which (in certain selinux setups) causes audit messages to
get logged.  Switch them to has_capability_noaudit.

Fixes: 7317a03df7 ("xfs: refactor inode ownership change transaction/inode/quota allocation idiom")
Fixes: ea9a46e1c4 ("xfs: only return detailed fsmap info if the caller has CAP_SYS_ADMIN")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2022-03-09 10:32:06 -08:00
Gao Xiang
1a39ae415c xfs: add missing cmap->br_state = XFS_EXT_NORM update
COW extents are already converted into written real extents after
xfs_reflink_convert_cow_locked(), therefore cmap->br_state should
reflect it.

Otherwise, there is another necessary unwritten convertion
triggered in xfs_dio_write_end_io() for direct I/O cases.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-09 10:32:06 -08:00
Linus Torvalds
7e57714cd0 Linux 5.17-rc6 2022-02-27 14:36:33 -08:00
Linus Torvalds
52a0255467 A single fix for a regression caused by the recent PCI/MSI rework which
resulted in a recursive locking problem in the VMD driver. The cure is to
 cache the relevant information upfront instead of retrieving it at runtime.
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Merge tag 'irq-urgent-2022-02-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fix from Thomas Gleixner:
 "A single fix for a regression caused by the recent PCI/MSI rework
  which resulted in a recursive locking problem in the VMD driver.

  The cure is to cache the relevant information upfront instead of
  retrieving it at runtime"

* tag 'irq-urgent-2022-02-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI: vmd: Prevent recursive locking on interrupt allocation
2022-02-27 13:07:40 -08:00
Linus Torvalds
98f3e84f8d dma-mapping fix for Linux 5.17
- fix a swiotlb info leak (Halil Pasic)
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Merge tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fix from Christoph Hellwig:

 - fix a swiotlb info leak (Halil Pasic)

* tag 'dma-mapping-5.17-1' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: fix info leak with DMA_FROM_DEVICE
2022-02-27 12:42:37 -08:00
Linus Torvalds
6676ba2a6d Pin control fixes for the v5.17 series:
- Fix some drive strength and pull-up code in the K210 driver.
 
 - Add the Alder Lake-M ACPI ID so it starts to work properly.
 
 - Use a static name for the StarFive GPIO irq_chip, forestalling
   an upcoming fixes series from Marc Zyngier.
 
 - Fix an ages old bug in the Tegra 186 driver where we were
   indexing at random into struct and being lucky getting the
   right member.
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Merge tag 'pinctrl-v5-17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

Pull pin control fixes from Linus Walleij:

 - Fix some drive strength and pull-up code in the K210 driver.

 - Add the Alder Lake-M ACPI ID so it starts to work properly.

 - Use a static name for the StarFive GPIO irq_chip, forestalling an
   upcoming fixes series from Marc Zyngier.

 - Fix an ages old bug in the Tegra 186 driver where we were indexing at
   random into struct and being lucky getting the right member.

* tag 'pinctrl-v5-17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  gpio: tegra186: Fix chip_data type confusion
  pinctrl: starfive: Use a static name for the GPIO irq_chip
  pinctrl: tigerlake: Revert "Add Alder Lake-M ACPI ID"
  pinctrl: k210: Fix bias-pull-up
  pinctrl: fix loop in k210_pinconf_get_drive()
2022-02-27 12:30:54 -08:00
Linus Torvalds
2293be58d6 Tracing fixes for 5.17:
- rtla (Real-Time Linux Analysis tool): fix typo in man page
 
  - rtla: Update API -e to -E before it is released
 
  - rlla: Error message fix and memory leak fix
 
  - Partially uninline trace event soft disable to shrink text
 
  - Fix function graph start up test
 
  - Have triggers affect the trace instance they are in and not top level
 
  - Have osnoise sleep in the units it says it uses
 
  - Remove unused ftrace stub function
 
  - Remove event probe redundant info from event in the buffer
 
  - Fix group ownership setting in tracefs
 
  - Ensure trace buffer is minimum size to prevent crashes
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Merge tag 'trace-v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - rtla (Real-Time Linux Analysis tool):
    - fix typo in man page
    - Update API -e to -E before it is released
    - Error message fix and memory leak fix

 - Partially uninline trace event soft disable to shrink text

 - Fix function graph start up test

 - Have triggers affect the trace instance they are in and not top level

 - Have osnoise sleep in the units it says it uses

 - Remove unused ftrace stub function

 - Remove event probe redundant info from event in the buffer

 - Fix group ownership setting in tracefs

 - Ensure trace buffer is minimum size to prevent crashes

* tag 'trace-v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  rtla/osnoise: Fix error message when failing to enable trace instance
  rtla/osnoise: Free params at the exit
  rtla/hist: Make -E the short version of --entries
  tracing: Fix selftest config check for function graph start up test
  tracefs: Set the group ownership in apply_options() not parse_options()
  tracing/osnoise: Make osnoise_main to sleep for microseconds
  ftrace: Remove unused ftrace_startup_enable() stub
  tracing: Ensure trace buffer is at least 4096 bytes large
  tracing: Uninline trace_trigger_soft_disabled() partly
  eprobes: Remove redundant event type information
  tracing: Have traceon and traceoff trigger honor the instance
  tracing: Dump stacktrace trigger to the corresponding instance
  rtla: Fix systme -> system typo on man page
2022-02-26 12:10:17 -08:00
Linus Torvalds
e41898d2ba memblock: use kfree() to release kmalloced memblock regions
memblock.{reserved,memory}.regions may be allocated using kmalloc() in
 memblock_double_array(). Use kfree() to release these kmalloced regions.
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Merge tag 'fixes-2022-02-26' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fix from Mike Rapoport:
 "Use kfree() to release kmalloced memblock regions

  memblock.{reserved,memory}.regions may be allocated using kmalloc()
  in memblock_double_array(). Use kfree() to release these kmalloced
  regions"

* tag 'fixes-2022-02-26' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock: use kfree() to release kmalloced memblock regions
2022-02-26 12:00:44 -08:00
Linus Torvalds
086ee11b03 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "12 patches.

  Subsystems affected by this patch series: MAINTAINERS, mailmap, memfd,
  and mm (hugetlb, kasan, hugetlbfs, pagemap, selftests, memcg, and
  slab)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  selftests/memfd: clean up mapping in mfd_fail_write
  mailmap: update Roman Gushchin's email
  MAINTAINERS, SLAB: add Roman as reviewer, git tree
  MAINTAINERS: add Shakeel as a memcg co-maintainer
  MAINTAINERS: remove Vladimir from memcg maintainers
  MAINTAINERS: add Roman as a memcg co-maintainer
  selftest/vm: fix map_fixed_noreplace test failure
  mm: fix use-after-free bug when mm->mmap is reused after being freed
  hugetlbfs: fix a truncation issue in hugepages parameter
  kasan: test: prevent cache merging in kmem_cache_double_destroy
  mm/hugetlb: fix kernel crash with hugetlb mremap
  MAINTAINERS: add sysctl-next git tree
2022-02-26 11:52:14 -08:00
Linus Torvalds
2c8c230eda RISC-V Fixes for 5.17-rc6
* A fix for the K210 sdcard defconfig, to avoid using a fixed delay for
   the root FS.
 * A fix to make sure there's a proper call frame for
   trace_hardirqs_{on,off}().
 
 ---
 
 There are a handful of additional fixes in flight, but not for this
 week.
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Merge tag 'riscv-for-linus-5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for the K210 sdcard defconfig, to avoid using a
   fixed delay for the root FS

 - A fix to make sure there's a proper call frame for
   trace_hardirqs_{on,off}().

* tag 'riscv-for-linus-5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix oops caused by irqsoff latency tracer
  riscv: fix nommu_k210_sdcard_defconfig
2022-02-26 10:26:24 -08:00
Linus Torvalds
3bd9dd8138 Bug fixes for 5.17-rc4:
- Only call sync_filesystem when we're remounting the filesystem
    readonly readonly, and actually check its return value.
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Merge tag 'xfs-5.17-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "Nothing exciting, just more fixes for not returning sync_filesystem
  error values (and eliding it when it's not necessary).

  Summary:

   - Only call sync_filesystem when we're remounting the filesystem
     readonly readonly, and actually check its return value"

* tag 'xfs-5.17-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: only bother with sync_filesystem during readonly remount
2022-02-26 09:53:19 -08:00
Mike Kravetz
fda153c89a selftests/memfd: clean up mapping in mfd_fail_write
Running the memfd script ./run_hugetlbfs_test.sh will often end in error
as follows:

    memfd-hugetlb: CREATE
    memfd-hugetlb: BASIC
    memfd-hugetlb: SEAL-WRITE
    memfd-hugetlb: SEAL-FUTURE-WRITE
    memfd-hugetlb: SEAL-SHRINK
    fallocate(ALLOC) failed: No space left on device
    ./run_hugetlbfs_test.sh: line 60: 166855 Aborted                 (core dumped) ./memfd_test hugetlbfs
    opening: ./mnt/memfd
    fuse: DONE

If no hugetlb pages have been preallocated, run_hugetlbfs_test.sh will
allocate 'just enough' pages to run the test.  In the SEAL-FUTURE-WRITE
test the mfd_fail_write routine maps the file, but does not unmap.  As a
result, two hugetlb pages remain reserved for the mapping.  When the
fallocate call in the SEAL-SHRINK test attempts allocate all hugetlb
pages, it is short by the two reserved pages.

Fix by making sure to unmap in mfd_fail_write.

Link: https://lkml.kernel.org/r/20220219004340.56478-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Roman Gushchin
9502bdbf34 mailmap: update Roman Gushchin's email
I'm moving to a @linux.dev account. Map my old addresses.

Link: https://lkml.kernel.org/r/20220221200006.416377-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Vlastimil Babka
7b0112f343 MAINTAINERS, SLAB: add Roman as reviewer, git tree
The slab code has an overlap with kmem accounting, where Roman has done
a lot of work recently and it would be useful to make sure he's CC'd on
patches that potentially affect it.  Thus add him as a reviewer for the
SLAB subsystem.

Also while at it, add the link to slab git tree.

Link: https://lkml.kernel.org/r/20220222103104.13241-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Shakeel Butt
bb9d545499 MAINTAINERS: add Shakeel as a memcg co-maintainer
I have been contributing and reviewing to the memcg codebase for last
couple of years.  So, making it official.

Link: https://lkml.kernel.org/r/20220224060148.4092228-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Vladimir Davydov
0a972e72e2 MAINTAINERS: remove Vladimir from memcg maintainers
Link: https://lkml.kernel.org/r/4ad1f8da49d7b71c84a0c15bd5347f5ce704e730.1645608825.git.vdavydov.dev@gmail.com
Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Roman Gushchin
7d547dcf97 MAINTAINERS: add Roman as a memcg co-maintainer
Add myself as a memcg co-maintainer.  My primary focus over last few
years was the kernel memory accounting stack, but I do work on some
other parts of the memory controller as well.

Link: https://lkml.kernel.org/r/20220221233951.659048-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Aneesh Kumar K.V
f39c58008d selftest/vm: fix map_fixed_noreplace test failure
On the latest RHEL the test fails due to executable mapped at 256MB
address

     # ./map_fixed_noreplace
    mmap() @ 0x10000000-0x10050000 p=0xffffffffffffffff result=File exists
    10000000-10010000 r-xp 00000000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10010000-10020000 r--p 00000000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10020000-10030000 rw-p 00010000 fd:04 34905657                           /root/rpmbuild/BUILD/kernel-5.14.0-56.el9/linux-5.14.0-56.el9.ppc64le/tools/testing/selftests/vm/map_fixed_noreplace
    10029b90000-10029bc0000 rw-p 00000000 00:00 0                            [heap]
    7fffbb510000-7fffbb750000 r-xp 00000000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb750000-7fffbb760000 r--p 00230000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb760000-7fffbb770000 rw-p 00240000 fd:04 24534                      /usr/lib64/libc.so.6
    7fffbb780000-7fffbb7a0000 r--p 00000000 00:00 0                          [vvar]
    7fffbb7a0000-7fffbb7b0000 r-xp 00000000 00:00 0                          [vdso]
    7fffbb7b0000-7fffbb800000 r-xp 00000000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffbb800000-7fffbb810000 r--p 00040000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffbb810000-7fffbb820000 rw-p 00050000 fd:04 24514                      /usr/lib64/ld64.so.2
    7fffd93f0000-7fffd9420000 rw-p 00000000 00:00 0                          [stack]
    Error: couldn't map the space we need for the test

Fix this by finding a free address using mmap instead of hardcoding
BASE_ADDRESS.

Link: https://lkml.kernel.org/r/20220217083417.373823-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Suren Baghdasaryan
f798a1d4f9 mm: fix use-after-free bug when mm->mmap is reused after being freed
oom reaping (__oom_reap_task_mm) relies on a 2 way synchronization with
exit_mmap.  First it relies on the mmap_lock to exclude from unlock
path[1], page tables tear down (free_pgtables) and vma destruction.
This alone is not sufficient because mm->mmap is never reset.

For historical reasons[2] the lock is taken there is also MMF_OOM_SKIP
set for oom victims before.

The oom reaper only ever looks at oom victims so the whole scheme works
properly but process_mrelease can opearate on any task (with fatal
signals pending) which doesn't really imply oom victims.  That means
that the MMF_OOM_SKIP part of the synchronization doesn't work and it
can see a task after the whole address space has been demolished and
traverse an already released mm->mmap list.  This leads to use after
free as properly caught up by KASAN report.

Fix the issue by reseting mm->mmap so that MMF_OOM_SKIP synchronization
is not needed anymore.  The MMF_OOM_SKIP is not removed from exit_mmap
yet but it acts mostly as an optimization now.

[1] 27ae357fa8 ("mm, oom: fix concurrent munlock and oom reaper unmap, v3")
[2] 2129258024 ("mm: oom: let oom_reap_task and exit_mmap run concurrently")

[mhocko@suse.com: changelog rewrite]

Link: https://lore.kernel.org/all/00000000000072ef2c05d7f81950@google.com/
Link: https://lkml.kernel.org/r/20220215201922.1908156-1-surenb@google.com
Fixes: 64591e8605 ("mm: protect free_pgtables with mmap_lock write lock in exit_mmap")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: syzbot+2ccf63a4bd07cf39cab0@syzkaller.appspotmail.com
Suggested-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Liu Yuntao
e79ce98323 hugetlbfs: fix a truncation issue in hugepages parameter
When we specify a large number for node in hugepages parameter, it may
be parsed to another number due to truncation in this statement:

	node = tmp;

For example, add following parameter in command line:

	hugepagesz=1G hugepages=4294967297:5

and kernel will allocate 5 hugepages for node 1 instead of ignoring it.

I move the validation check earlier to fix this issue, and slightly
simplifies the condition here.

Link: https://lkml.kernel.org/r/20220209134018.8242-1-liuyuntao10@huawei.com
Fixes: b5389086ad ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
Signed-off-by: Liu Yuntao <liuyuntao10@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Andrey Konovalov
70effdc375 kasan: test: prevent cache merging in kmem_cache_double_destroy
With HW_TAGS KASAN and kasan.stacktrace=off, the cache created in the
kmem_cache_double_destroy() test might get merged with an existing one.
Thus, the first kmem_cache_destroy() call won't actually destroy it but
will only decrease the refcount.  This causes the test to fail.

Provide an empty constructor for the created cache to prevent the cache
from getting merged.

Link: https://lkml.kernel.org/r/b597bd434c49591d8af00ee3993a42c609dc9a59.1644346040.git.andreyknvl@google.com
Fixes: f98f966cd7 ("kasan: test: add test case for double-kmem_cache_destroy()")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Aneesh Kumar K.V
db110a99d3 mm/hugetlb: fix kernel crash with hugetlb mremap
This fixes the below crash:

  kernel BUG at include/linux/mm.h:2373!
  cpu 0x5d: Vector: 700 (Program Check) at [c00000003c6e76e0]
      pc: c000000000581a54: pmd_to_page+0x54/0x80
      lr: c00000000058d184: move_hugetlb_page_tables+0x4e4/0x5b0
      sp: c00000003c6e7980
     msr: 9000000000029033
    current = 0xc00000003bd8d980
    paca    = 0xc000200fff610100   irqmask: 0x03   irq_happened: 0x01
      pid   = 9349, comm = hugepage-mremap
  kernel BUG at include/linux/mm.h:2373!
    move_hugetlb_page_tables+0x4e4/0x5b0 (link register)
    move_hugetlb_page_tables+0x22c/0x5b0 (unreliable)
    move_page_tables+0xdbc/0x1010
    move_vma+0x254/0x5f0
    sys_mremap+0x7c0/0x900
    system_call_exception+0x160/0x2c0

the kernel can't use huge_pte_offset before it set the pte entry because
a page table lookup check for huge PTE bit in the page table to
differentiate between a huge pte entry and a pointer to pte page.  A
huge_pte_alloc won't mark the page table entry huge and hence kernel
should not use huge_pte_offset after a huge_pte_alloc.

Link: https://lkml.kernel.org/r/20220211063221.99293-1-aneesh.kumar@linux.ibm.com
Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00
Luis Chamberlain
bbcf7b0e2e MAINTAINERS: add sysctl-next git tree
Add a git tree for sysctls as there's been quite a bit of work lately to
remove all the syctls out of kernel/sysctl.c and move to their respective
places, so coordination has been needed to avoid conflicts.  This tree
will also help soak these changes on linux-next prior to getting to Linus.

Link: https://lkml.kernel.org/r/20220218182736.3694508-1-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-26 09:51:17 -08:00