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  1. 23 1月, 2021 5 次提交
    • B
      xfs: separate log cleaning from log quiesce · 9e54ee0f
      由 Brian Foster 提交于 
      Log quiesce is currently associated with cleaning the log, which is
accomplished by writing an unmount record as the last step of the
quiesce sequence. The quiesce codepath is a bit convoluted in this
regard due to how it is reused from various contexts. In preparation
to create separate log cleaning and log covering interfaces, lift
the write of the unmount record into a new cleaning helper and call
that wherever xfs_log_quiesce() is currently invoked. No functional
changes.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
      9e54ee0f
    • B
      xfs: lift writable fs check up into log worker task · 37444fc4
      由 Brian Foster 提交于 
      The log covering helper checks whether the filesystem is writable to
determine whether to cover the log. The helper is currently only
called from the background log worker. In preparation to reuse the
helper from freezing contexts, lift the check into xfs_log_worker().
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
      37444fc4
    • B
      xfs: sync lazy sb accounting on quiesce of read-only mounts · 50d25484
      由 Brian Foster 提交于 
      xfs_log_sbcount() syncs the superblock specifically to accumulate
the in-core percpu superblock counters and commit them to disk. This
is required to maintain filesystem consistency across quiesce
(freeze, read-only mount/remount) or unmount when lazy superblock
accounting is enabled because individual transactions do not update
the superblock directly.

This mechanism works as expected for writable mounts, but
xfs_log_sbcount() skips the update for read-only mounts. Read-only
mounts otherwise still allow log recovery and write out an unmount
record during log quiesce. If a read-only mount performs log
recovery, it can modify the in-core superblock counters and write an
unmount record when the filesystem unmounts without ever syncing the
in-core counters. This leaves the filesystem with a clean log but in
an inconsistent state with regard to lazy sb counters.

Update xfs_log_sbcount() to use the same logic
xfs_log_unmount_write() uses to determine when to write an unmount
record. This ensures that lazy accounting is always synced before
the log is cleaned. Refactor this logic into a new helper to
distinguish between a writable filesystem and a writable log.
Specifically, the log is writable unless the filesystem is mounted
with the norecovery mount option, the underlying log device is
read-only, or the filesystem is shutdown. Drop the freeze state
check because the update is already allowed during the freezing
process and no context calls this function on an already frozen fs.
Also, retain the shutdown check in xfs_log_unmount_write() to catch
the case where the preceding log force might have triggered a
shutdown.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NGao Xiang <hsiangkao@redhat.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
      50d25484
    • B
      xfs: don't drain buffer lru on freeze and read-only remount · 8321ddb2
      由 Brian Foster 提交于 
      xfs_buftarg_drain() is called from xfs_log_quiesce() to ensure the
buffer cache is reclaimed during unmount. xfs_log_quiesce() is also
called from xfs_quiesce_attr(), however, which means that cache
state is completely drained for filesystem freeze and read-only
remount. While technically harmless, this is unnecessarily
heavyweight. Both freeze and read-only mounts allow reads and thus
allow population of the buffer cache. Therefore, the transitional
sequence in either case really only needs to quiesce outstanding
writes to return the filesystem in a generally read-only state.

Additionally, some users have reported that attempts to freeze a
filesystem concurrent with a read-heavy workload causes the freeze
process to stall for a significant amount of time. This occurs
because, as mentioned above, the read workload repopulates the
buffer LRU while the freeze task attempts to drain it.

To improve this situation, replace the drain in xfs_log_quiesce()
with a buffer I/O quiesce and lift the drain into the unmount path.
This removes buffer LRU reclaim from freeze and read-only [re]mount,
but ensures the LRU is still drained before the filesystem unmounts.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
      8321ddb2
    • B
      xfs: rename xfs_wait_buftarg() to xfs_buftarg_drain() · 10fb9ac1
      由 Brian Foster 提交于 
      xfs_wait_buftarg() is vaguely named and somewhat overloaded. Its
primary purpose is to reclaim all buffers from the provided buffer
target LRU. In preparation to refactor xfs_wait_buftarg() into
serialization and LRU draining components, rename the function and
associated helpers to something more descriptive. This patch has no
functional changes with the minor exception of renaming a
tracepoint.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
      10fb9ac1
  3. 07 10月, 2020 1 次提交
  5. 24 9月, 2020 1 次提交
  7. 29 7月, 2020 1 次提交
  9. 27 3月, 2020 10 次提交
  11. 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
  13. 23 3月, 2020 7 次提交
  15. 14 3月, 2020 3 次提交
  17. 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
  19. 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
  21. 19 11月, 2019 1 次提交
  23. 11 11月, 2019 1 次提交
  25. 06 11月, 2019 1 次提交
  27. 22 10月, 2019 6 次提交