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  1. 27 3月, 2020 5 次提交
  3. 26 3月, 2020 1 次提交
    • B
      xfs: shutdown on failure to add page to log bio · 842a42d1
      由 Brian Foster 提交于 
      If the bio_add_page() call fails, we proceed to write out a
partially constructed log buffer. This corrupts the physical log
such that log recovery is not possible. Worse, persistent
occurrences of this error eventually lead to a BUG_ON() failure in
bio_split() as iclogs wrap the end of the physical log, which
triggers log recovery on subsequent mount.

Rather than warn about writing out a corrupted log buffer, shutdown
the fs as is done for any log I/O related error. This preserves the
consistency of the physical log such that log recovery succeeds on a
subsequent mount. Note that this was observed on a 64k page debug
kernel without upstream commit 59bb4798 ("mm, sl[aou]b:
guarantee natural alignment for kmalloc(power-of-two)"), which
demonstrated frequent iclog bio overflows due to unaligned (slab
allocated) iclog data buffers.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      842a42d1
  5. 23 3月, 2020 7 次提交
  7. 14 3月, 2020 3 次提交
  9. 03 3月, 2020 1 次提交
    • B
      xfs: fix iclog release error check race with shutdown · 6b789c33
      由 Brian Foster 提交于 
      Prior to commit df732b29 ("xfs: call xlog_state_release_iclog with
l_icloglock held"), xlog_state_release_iclog() always performed a
locked check of the iclog error state before proceeding into the
sync state processing code. As of this commit, part of
xlog_state_release_iclog() was open-coded into
xfs_log_release_iclog() and as a result the locked error state check
was lost.

The lockless check still exists, but this doesn't account for the
possibility of a race with a shutdown being performed by another
task causing the iclog state to change while the original task waits
on ->l_icloglock. This has reproduced very rarely via generic/475
and manifests as an assert failure in __xlog_state_release_iclog()
due to an unexpected iclog state.

Restore the locked error state check in xlog_state_release_iclog()
to ensure that an iclog state update via shutdown doesn't race with
the iclog release state processing code.

Fixes: df732b29 ("xfs: call xlog_state_release_iclog with l_icloglock held")
Reported-by: NZorro Lang <zlang@redhat.com>
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      6b789c33
  11. 04 12月, 2019 1 次提交
    • B
      xfs: fix mount failure crash on invalid iclog memory access · 798a9cad
      由 Brian Foster 提交于 
      syzbot (via KASAN) reports a use-after-free in the error path of
xlog_alloc_log(). Specifically, the iclog freeing loop doesn't
handle the case of a fully initialized ->l_iclog linked list.
Instead, it assumes that the list is partially constructed and NULL
terminated.

This bug manifested because there was no possible error scenario
after iclog list setup when the original code was added.  Subsequent
code and associated error conditions were added some time later,
while the original error handling code was never updated. Fix up the
error loop to terminate either on a NULL iclog or reaching the end
of the list.

Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      798a9cad
  13. 19 11月, 2019 1 次提交
  15. 11 11月, 2019 1 次提交
  17. 06 11月, 2019 1 次提交
  19. 22 10月, 2019 7 次提交
  21. 07 10月, 2019 1 次提交
  23. 06 9月, 2019 7 次提交
    • D
      xfs: push the grant head when the log head moves forward · 14e15f1b
      由 Dave Chinner 提交于 
      When the log fills up, we can get into the state where the
outstanding items in the CIL being committed and aggregated are
larger than the range that the reservation grant head tail pushing
will attempt to clean. This can result in the tail pushing range
being trimmed back to the the log head (l_last_sync_lsn) and so
may not actually move the push target at all.

When the iclogs associated with the CIL commit finally land, the
log head moves forward, and this removes the restriction on the AIL
push target. However, if we already have transactions sleeping on
the grant head, and there's nothing in the AIL still to flush from
the current push target, then nothing will move the tail of the log
and trigger a log reservation wakeup.

Hence the there is nothing that will trigger xlog_grant_push_ail()
to recalculate the AIL push target and start pushing on the AIL
again to write back the metadata objects that pin the tail of the
log and hence free up space and allow the transaction reservations
to be woken and make progress.

Hence we need to push on the grant head when we move the log head
forward, as this may be the only trigger we have that can move the
AIL push target forwards in this situation.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      14e15f1b
    • D
      xfs: push iclog state cleaning into xlog_state_clean_log · 0383f543
      由 Dave Chinner 提交于 
      xlog_state_clean_log() is only called from one place, and it occurs
when an iclog is transitioning back to ACTIVE. Prior to calling
xlog_state_clean_log, the iclog we are processing has a hard coded
state check to DIRTY so that xlog_state_clean_log() processes it
correctly. We also have a hard coded wakeup after
xlog_state_clean_log() to enfore log force waiters on that iclog
are woken correctly.

Both of these things are operations required to finish processing an
iclog and return it to the ACTIVE state again, so they make little
sense to be separated from the rest of the clean state transition
code.

Hence push these things inside xlog_state_clean_log(), document the
behaviour and rename it xlog_state_clean_iclog() to indicate that
it's being driven by an iclog state change and does the iclog state
change work itself.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      0383f543
    • D
      xfs: factor iclog state processing out of xlog_state_do_callback() · 5e96fa8d
      由 Dave Chinner 提交于 
      The iclog IO completion state processing is somewhat complex, and
because it's inside two nested loops it is highly indented and very
hard to read. Factor it out, flatten the logic flow and clean up the
comments so that it much easier to see what the code is doing both
in processing the individual iclogs and in the over
xlog_state_do_callback() operation.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      5e96fa8d
    • D
      xfs: factor callbacks out of xlog_state_do_callback() · 6546818c
      由 Dave Chinner 提交于 
      Simplify the code flow by lifting the iclog callback work out of
the main iclog iteration loop. This isolates the log juggling and
callbacks from the iclog state change logic in the loop.

Note that the loopdidcallbacks variable is not actually tracking
whether callbacks are actually run - it is tracking whether the
icloglock was dropped during the loop and so determines if we
completed the entire iclog scan loop atomically. Hence we know for
certain there are either no more ordered completions to run or
that the next completion will run the remaining ordered iclog
completions. Hence rename that variable appropriately for it's
function.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      6546818c
    • D
      xfs: factor debug code out of xlog_state_do_callback() · 6769aa2a
      由 Dave Chinner 提交于 
      Start making this function readable by lifting the debug code into
a conditional function.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      6769aa2a
    • R
      xfs: fix missed wakeup on l_flush_wait · cdea5459
      由 Rik van Riel 提交于 
      The code in xlog_wait uses the spinlock to make adding the task to
the wait queue, and setting the task state to UNINTERRUPTIBLE atomic
with respect to the waker.

Doing the wakeup after releasing the spinlock opens up the following
race condition:

Task 1					task 2
add task to wait queue
					wake up task
set task state to UNINTERRUPTIBLE

This issue was found through code inspection as a result of kworkers
being observed stuck in UNINTERRUPTIBLE state with an empty
wait queue. It is rare and largely unreproducable.

Simply moving the spin_unlock to after the wake_up_all results
in the waker not being able to see a task on the waitqueue before
it has set its state to UNINTERRUPTIBLE.

This bug dates back to the conversion of this code to generic
waitqueue infrastructure from a counting semaphore back in 2008
which didn't place the wakeups consistently w.r.t. to the relevant
spin locks.

[dchinner: Also fix a similar issue in the shutdown path on
xc_commit_wait. Update commit log with more details of the issue.]

Fixes: d748c623 ("[XFS] Convert l_flushsema to a sv_t")
Reported-by: NChris Mason <clm@fb.com>
Signed-off-by: NRik van Riel <riel@surriel.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      cdea5459
    • D
      xfs: push the AIL in xlog_grant_head_wake · 7c107afb
      由 Dave Chinner 提交于 
      In the situation where the log is full and the CIL has not recently
flushed, the AIL push threshold is throttled back to the where the
last write of the head of the log was completed. This is stored in
log->l_last_sync_lsn. Hence if the CIL holds > 25% of the log space
pinned by flushes and/or aggregation in progress, we can get the
situation where the head of the log lags a long way behind the
reservation grant head.

When this happens, the AIL push target is trimmed back from where
the reservation grant head wants to push the log tail to, back to
where the head of the log currently is. This means the push target
doesn't reach far enough into the log to actually move the tail
before the transaction reservation goes to sleep.

When the CIL push completes, it moves the log head forward such that
the AIL push target can now be moved, but that has no mechanism for
puhsing the log tail. Further, if the next tail movement of the log
is not large enough wake the waiter (i.e. still not enough space for
it to have a reservation granted), we don't wake anything up, and
hence we do not update the AIL push target to take into account the
head of the log moving and allowing the push target to be moved
forwards.

To avoid this particular condition, if we fail to wake the first
waiter on the grant head because we don't have enough space,
push on the AIL again. This will pick up any movement of the log
head and allow the push target to move forward due to completion of
CIL pushing.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      7c107afb
  25. 27 8月, 2019 2 次提交
    • D
      xfs: add kmem_alloc_io() · f8f9ee47
      由 Dave Chinner 提交于 
      Memory we use to submit for IO needs strict alignment to the
underlying driver contraints. Worst case, this is 512 bytes. Given
that all allocations for IO are always a power of 2 multiple of 512
bytes, the kernel heap provides natural alignment for objects of
these sizes and that suffices.

Until, of course, memory debugging of some kind is turned on (e.g.
red zones, poisoning, KASAN) and then the alignment of the heap
objects is thrown out the window. Then we get weird IO errors and
data corruption problems because drivers don't validate alignment
and do the wrong thing when passed unaligned memory buffers in bios.

TO fix this, introduce kmem_alloc_io(), which will guaranteeat least
512 byte alignment of buffers for IO, even if memory debugging
options are turned on. It is assumed that the minimum allocation
size will be 512 bytes, and that sizes will be power of 2 mulitples
of 512 bytes.

Use this everywhere we allocate buffers for IO.

This no longer fails with log recovery errors when KASAN is enabled
due to the brd driver not handling unaligned memory buffers:

# mkfs.xfs -f /dev/ram0 ; mount /dev/ram0 /mnt/test
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      f8f9ee47
    • T
      fs: xfs: Remove KM_NOSLEEP and KM_SLEEP. · 707e0dda
      由 Tetsuo Handa 提交于 
      Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP,
we can remove KM_NOSLEEP and replace KM_SLEEP with 0.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      707e0dda
  27. 04 8月, 2019 1 次提交
    • T
      fs: xfs: xfs_log: Don't use KM_MAYFAIL at xfs_log_reserve(). · 294fc7a4
      由 Tetsuo Handa 提交于 
      When the system is close-to-OOM, fsync() may fail due to -ENOMEM because
xfs_log_reserve() is using KM_MAYFAIL. It is a bad thing to fail writeback
operation due to user-triggerable OOM condition. Since we are not using
KM_MAYFAIL at xfs_trans_alloc() before calling xfs_log_reserve(), let's
use the same flags at xfs_log_reserve().

  oom-torture: page allocation failure: order:0, mode:0x46c40(GFP_NOFS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), nodemask=(null)
  CPU: 7 PID: 1662 Comm: oom-torture Kdump: loaded Not tainted 5.3.0-rc2+ #925
  Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00
  Call Trace:
   dump_stack+0x67/0x95
   warn_alloc+0xa9/0x140
   __alloc_pages_slowpath+0x9a8/0xbce
   __alloc_pages_nodemask+0x372/0x3b0
   alloc_slab_page+0x3a/0x8d0
   new_slab+0x330/0x420
   ___slab_alloc.constprop.94+0x879/0xb00
   __slab_alloc.isra.89.constprop.93+0x43/0x6f
   kmem_cache_alloc+0x331/0x390
   kmem_zone_alloc+0x9f/0x110 [xfs]
   kmem_zone_alloc+0x9f/0x110 [xfs]
   xlog_ticket_alloc+0x33/0xd0 [xfs]
   xfs_log_reserve+0xb4/0x410 [xfs]
   xfs_trans_reserve+0x1d1/0x2b0 [xfs]
   xfs_trans_alloc+0xc9/0x250 [xfs]
   xfs_setfilesize_trans_alloc.isra.27+0x44/0xc0 [xfs]
   xfs_submit_ioend.isra.28+0xa5/0x180 [xfs]
   xfs_vm_writepages+0x76/0xa0 [xfs]
   do_writepages+0x17/0x80
   __filemap_fdatawrite_range+0xc1/0xf0
   file_write_and_wait_range+0x53/0xa0
   xfs_file_fsync+0x87/0x290 [xfs]
   vfs_fsync_range+0x37/0x80
   do_fsync+0x38/0x60
   __x64_sys_fsync+0xf/0x20
   do_syscall_64+0x4a/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: eb01c9cd ("[XFS] Remove the xlog_ticket allocator")
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      294fc7a4
  29. 03 7月, 2019 1 次提交