[PATCH v2 0/2] xfs: fix buffer delwri queue state race

[Brian Foster <bfoster@redhat.com>]

Hi all,

Here's a v2 of the patches to fix the buffer delwri queue state race
problem (documented in the patch 2 commit log). This takes a completely
different approach from v1, as suggested by Dave during review of v1.

Patch 1 refactors the buffer submission paths and patch 2 closes the
race by using synchronous buffer I/O for synchronous delwri queues. This
survives a full xfstests run as well as lowmem stress testing of
xfs/305 [1].

Thoughts, reviews, flames appreciated.

Brian

[1] If run long enough, I do eventually hit some presumably unrelated
issues that are not currently reproducible simply due to the fact that
the delwri queue issue is more prevalent.

v2:
- Implement sync buffer I/O for sync delwri queues instead of buffer
  wait list stealing.
v1: https://marc.info/?l=linux-xfs&m=152837528705511&w=2

Brian Foster (2):
  xfs: refactor buffer submission into a common helper
  xfs: use sync buffer I/O for sync delwri queue submission

 fs/xfs/xfs_buf.c | 164 +++++++++++++++++++++++------------------------
 1 file changed, 79 insertions(+), 85 deletions(-)

-- 
2.17.1