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  1. 16 11月, 2019 1 次提交
  3. 14 11月, 2019 2 次提交
  5. 11 11月, 2019 1 次提交
  7. 08 11月, 2019 1 次提交
  9. 05 11月, 2019 1 次提交
  11. 07 10月, 2019 1 次提交
  13. 06 9月, 2019 1 次提交
    • D
      xfs: prevent CIL push holdoff in log recovery · 8ab39f11
      由 Dave Chinner 提交于 
      generic/530 on a machine with enough ram and a non-preemptible
kernel can run the AGI processing phase of log recovery enitrely out
of cache. This means it never blocks on locks, never waits for IO
and runs entirely through the unlinked lists until it either
completes or blocks and hangs because it has run out of log space.

It runs out of log space because the background CIL push is
scheduled but never runs. queue_work() queues the CIL work on the
current CPU that is busy, and the workqueue code will not run it on
any other CPU. Hence if the unlinked list processing never yields
the CPU voluntarily, the push work is delayed indefinitely. This
results in the CIL aggregating changes until all the log space is
consumed.

When the log recoveyr processing evenutally blocks, the CIL flushes
but because the last iclog isn't submitted for IO because it isn't
full, the CIL flush never completes and nothing ever moves the log
head forwards, or indeed inserts anything into the tail of the log,
and hence nothing is able to get the log moving again and recovery
hangs.

There are several problems here, but the two obvious ones from
the trace are that:
	a) log recovery does not yield the CPU for over 4 seconds,
	b) binding CIL pushes to a single CPU is a really bad idea.

This patch addresses just these two aspects of the problem, and are
suitable for backporting to work around any issues in older kernels.
The more fundamental problem of preventing the CIL from consuming
more than 50% of the log without committing will take more invasive
and complex work, so will be done as followup work.
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>
      8ab39f11
  15. 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
  17. 03 7月, 2019 1 次提交
  19. 29 6月, 2019 8 次提交
  21. 12 6月, 2019 3 次提交
  23. 02 5月, 2019 1 次提交
  25. 19 2月, 2019 1 次提交
  27. 12 2月, 2019 3 次提交
  29. 13 12月, 2018 1 次提交
  31. 29 9月, 2018 1 次提交
    • B
      xfs: remove invalid log recovery first/last cycle check · ec2ed0b5
      由 Brian Foster 提交于 
      One of the first steps of log recovery is to check for the special
case of a zeroed log. If the first cycle in the log is zero or the
tail portion of the log is zeroed, the head is set to the first
instance of cycle 0. xlog_find_zeroed() includes a sanity check that
enforces that the first cycle in the log must be 1 if the last cycle
is 0. While this is true in most cases, the check is not totally
valid because it doesn't consider the case where the filesystem
crashed after a partial/out of order log buffer completion that
wraps around the end of the physical log.

For example, consider a filesystem that has completed most of the
first cycle of the log, reaches the end of the physical log and
splits the next single log buffer write into two in order to wrap
around the end of the log. If these I/Os are reordered, the second
(wrapped) I/O completes and the first happens to fail, the log is
left in a state where the last cycle of the log is 0 and the first
cycle is 2. This causes the xlog_find_zeroed() sanity check to fail
and prevents the filesystem from mounting. This situation has been
reproduced on particular systems via repeated runs of generic/475.

This is an expected state that log recovery already knows how to
deal with, however. Since the log is still partially zeroed, the
head is detected correctly and points to a valid tail. The
subsequent stale block detection clears blocks beyond the head up to
the tail (within a maximum range), with the express purpose of
clearing such out of order writes. As expected, this removes the out
of order cycle 2 blocks at the physical start of the log.

In other words, the only thing that prevents a clean mount and
recovery of the filesystem in this scenario is the specific (last ==
0 && first != 1) sanity check in xlog_find_zeroed(). Since the log
head/tail are now independently validated via cycle, log record and
CRC checks, this highly specific first cycle check is of dubious
value. Remove it and rely on the higher level validation to
determine whether log content is sane and recoverable.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>
      ec2ed0b5
  33. 03 8月, 2018 2 次提交
  35. 27 7月, 2018 5 次提交
  37. 12 7月, 2018 3 次提交
  39. 09 6月, 2018 1 次提交