[PATCH v6 0/8] blockdev: Fix AioContext handling for various blockdev actions

[Sergio Lopez <slp@redhat.com>]

This patch series includes fixes for various issues related to
AioContext mismanagement for various blockdev-initiated actions.

It also adds tests for those actions when executed on drives running
on an IOThread AioContext.

---
Changelog:

v6:
 - Rename the patch series.
 - Add "block/backup-top: Don't acquire context while dropping top"
 - Add "blockdev: Acquire AioContext on dirty bitmap functions"
 - Add "blockdev: Return bs to the proper context on snapshot abort"
 - Add "iotests: Test handling of AioContexts with some blockdev
   actions" (thanks Kevin Wolf)
 - Fix context release on error. (thanks Kevin Wolf)

v5:
 - Include fix for iotest 141 in patch 2. (thanks Max Reitz)
 - Also fix iotest 185 and 219 in patch 2. (thanks Max Reitz)
 - Move error block after context acquisition/release, to we can use
   goto to bail out and release resources. (thanks Max Reitz)
 - Properly release old_context in qmp_blockdev_mirror. (thanks Max
   Reitz)

v4:
 - Unify patches 1-4 and 5-7 to avoid producing broken interim
   states. (thanks Max Reitz)
 - Include a fix for iotest 141. (thanks Kevin Wolf)

v3:
 - Rework the whole patch series to fix the issue by consolidating all
   operations in the transaction model. (thanks Kevin Wolf)

v2:
 - Honor bdrv_try_set_aio_context() context acquisition requirements
   (thanks Max Reitz).
 - Release the context at drive_backup_prepare() instead of avoiding
   re-acquiring it at do_drive_baclup(). (thanks Max Reitz)
 - Convert a single patch into a two-patch series.
---

Sergio Lopez (8):
  blockdev: fix coding style issues in drive_backup_prepare
  blockdev: unify qmp_drive_backup and drive-backup transaction paths
  blockdev: unify qmp_blockdev_backup and blockdev-backup transaction
    paths
  blockdev: honor bdrv_try_set_aio_context() context requirements
  block/backup-top: Don't acquire context while dropping top
  blockdev: Acquire AioContext on dirty bitmap functions
  blockdev: Return bs to the proper context on snapshot abort
  iotests: Test handling of AioContexts with some blockdev actions

 block/backup-top.c         |   5 -
 block/backup.c             |   3 +
 blockdev.c                 | 391 ++++++++++++++++++++-----------------
 tests/qemu-iotests/141.out |   2 +
 tests/qemu-iotests/185.out |   2 +
 tests/qemu-iotests/219     |   7 +-
 tests/qemu-iotests/219.out |   8 +
 tests/qemu-iotests/281     | 247 +++++++++++++++++++++++
 tests/qemu-iotests/281.out |   5 +
 tests/qemu-iotests/group   |   1 +
 10 files changed, 484 insertions(+), 187 deletions(-)
 create mode 100755 tests/qemu-iotests/281
 create mode 100644 tests/qemu-iotests/281.out

-- 
2.23.0