[Devel] [PATCH VZ9 0/3] improve pio submission suspension

[Andrey Zhadchenko]

Recently we encountered EBUSY errors while trying to resize ploop
devices under load. This mostly happens because we are not waiting
in-progess IO correctly:
 - initial pio is removed from inflight even if its split pios are
still running
 - there are no wait for metadata writeback

This patchset fixes that by moving inflight decrease later and
introducing new counter for inflight metadata writeback.

Note that for dm-qcow2 patches are not needed: it does not have
delayed metadata writeback and inflight countera are decreased
correctly at the time of endio_cb

https://virtuozzo.atlassian.net/browse/VSTOR-108540
Andrey Zhadchenko (3):
  drivers/md/ploop: drop excessive wb delay disable during resize
  drivers/md/ploop: add inflight metadata writeback counter
  drivers/md/ploop: decrease inflight number after pio endio

 drivers/md/dm-ploop-cmd.c    | 12 +++++++++---
 drivers/md/dm-ploop-map.c    | 11 ++++++++++-
 drivers/md/dm-ploop-target.c |  2 ++
 drivers/md/dm-ploop.h        |  3 +++
 4 files changed, 24 insertions(+), 4 deletions(-)

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2.43.5