[Qemu-devel] [PATCH v2 00/22] block: Rework bdrv_close_all()

[Max Reitz <mreitz@redhat.com>]

Currently, bdrv_close_all() force-closes all BDSs with a BlockBackend,
which can lead to data corruption (see the iotest added in the final
patch of this series) and is most certainly very ugly.

This series reworks bdrv_close_all() to notify all owners of a
BlockBackend that they should release their reference (and additionally
the monitor releases all its references to BB-less BDSs). This way,
force-closing becomes unnecessary.

Also, blk_hide_on_behalf_of_do_drive_del() is removed. Yay!


This series depends on v2 of my series
"blockdev: BlockBackend and media" (or any later version), and on my
series "nbd: Drop BDS backpointer" (on the patch
"iotests: Add 'wait' functionality to _cleanup_qemu").


v2:
- Dropped old patches 1 (squashed into
  "blockdev: BlockBackend and media") and 20 (put into
  "nbd: Drop BDS backpointer")
- Patch 1: Added (required for patch 3)
- Patch 2: Added (required for patch 3); if someone has a better
  solution, I'd be very grateful
- Patch 3: Added a test which ensures that if the BDS an NBD server is
  attached to through a BB is ejected, that NBD server is stopped
- Patch 5: Replaces the old patch 5 (which removed the BDS close
  notifiers completely); as pointed out by Paolo, we do need the
  notifiers as eject notifiers for NBD, so this patch replaces the
  per-BDS close notifiers by an eject notifier for the BB which is
  called whenever blk_remove_bs() is called and removes a BDS tree from
  the BB
- Patch 7: Fixed up to fit onto patch 5
- Patch 11: s/namespaces/namespace/ [Eric]
- Patch 14: Rebase conflict due to the new bdrv_add_key() function


git-backport-diff against v1:

Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/22:[down] 'iotests: Move _filter_nbd into common.filter'
002/22:[down] 'iotests: Do not redirect qemu's stderr'
003/22:[down] 'iotests: Add test for eject under NBD server'
004/22:[----] [-C] 'quorum: Fix close path'
005/22:[down] 'block: Move BDS close notifiers into BB'
006/22:[----] [--] 'block: Add bdrv_close_all() notifiers'
007/22:[0075] [FC] 'block: Add bdrv_close_all() handlers'
008/22:[----] [-C] 'block: Use blk_remove_bs() in blk_delete()'
009/22:[----] [--] 'blockdev: Use blk_remove_bs() in do_drive_del()'
010/22:[----] [--] 'block: Make bdrv_close() static'
011/22:[0002] [FC] 'block: Add blk_name_taken()'
012/22:[----] [--] 'block: Add blk_next_inserted()'
013/22:[----] [--] 'block: Add blk_commit_all() and blk_invalidate_cache_all()'
014/22:[0009] [FC] 'block: Use BlockBackend more'
015/22:[----] [--] 'blockdev: Add list of monitor-owned BlockBackends'
016/22:[----] [--] 'blockdev: Remove blk_hide_on_behalf_of_do_drive_del()'
017/22:[----] [--] 'block: Make bdrv_drain_one() public'
018/22:[----] [-C] 'block: Move some bdrv_*_all() functions to BB'
019/22:[----] [--] 'block: Remove bdrv_states'
020/22:[----] [--] 'blockdev: Keep track of monitor-owned BDS'
021/22:[----] [--] 'block: Strip down bdrv_close_all()'
022/22:[----] [--] 'iotests: Add test for multiple BB on BDS tree'


Max Reitz (22):
  iotests: Move _filter_nbd into common.filter
  iotests: Do not redirect qemu's stderr
  iotests: Add test for eject under NBD server
  quorum: Fix close path
  block: Move BDS close notifiers into BB
  block: Add bdrv_close_all() notifiers
  block: Add bdrv_close_all() handlers
  block: Use blk_remove_bs() in blk_delete()
  blockdev: Use blk_remove_bs() in do_drive_del()
  block: Make bdrv_close() static
  block: Add blk_name_taken()
  block: Add blk_next_inserted()
  block: Add blk_commit_all() and blk_invalidate_cache_all()
  block: Use BlockBackend more
  blockdev: Add list of monitor-owned BlockBackends
  blockdev: Remove blk_hide_on_behalf_of_do_drive_del()
  block: Make bdrv_drain_one() public
  block: Move some bdrv_*_all() functions to BB
  block: Remove bdrv_states
  blockdev: Keep track of monitor-owned BDS
  block: Strip down bdrv_close_all()
  iotests: Add test for multiple BB on BDS tree

 block.c                          | 168 ++++------------------
 block/block-backend.c            | 301 +++++++++++++++++++++++++++++++--------
 block/qapi.c                     |  13 +-
 block/quorum.c                   |   3 +-
 block/snapshot.c                 |   3 +-
 blockdev-nbd.c                   |  36 +----
 blockdev.c                       | 121 +++++++++++++---
 cpus.c                           |   7 +-
 device-hotplug.c                 |   2 +-
 hw/block/xen_disk.c              |  16 ++-
 hw/ide/piix.c                    |   1 -
 include/block/block.h            |   9 +-
 include/block/block_int.h        |   8 +-
 include/sysemu/block-backend.h   |  24 ++--
 include/sysemu/blockdev.h        |   3 +
 migration/block.c                |  10 +-
 migration/migration.c            |   4 +-
 monitor.c                        |  13 +-
 nbd.c                            |  59 +++++++-
 qemu-char.c                      |   3 +-
 qemu-img.c                       |  39 ++---
 qemu-io.c                        |   8 +-
 qemu-nbd.c                       |   6 +-
 qmp.c                            |   9 +-
 savevm.c                         |  66 +++++----
 stubs/Makefile.objs              |   2 +-
 stubs/bdrv-commit-all.c          |   7 -
 stubs/blk-commit-all.c           |   7 +
 tests/qemu-iotests/083           |  13 +-
 tests/qemu-iotests/083.out       |  10 --
 tests/qemu-iotests/091           |   3 +-
 tests/qemu-iotests/096           |  89 ++++++++++++
 tests/qemu-iotests/096.out       |  16 +++
 tests/qemu-iotests/117           |  86 +++++++++++
 tests/qemu-iotests/117.out       |  14 ++
 tests/qemu-iotests/common.filter |  12 ++
 tests/qemu-iotests/common.qemu   |   1 -
 tests/qemu-iotests/group         |   2 +
 xen-mapcache.c                   |   3 +-
 39 files changed, 807 insertions(+), 390 deletions(-)
 delete mode 100644 stubs/bdrv-commit-all.c
 create mode 100644 stubs/blk-commit-all.c
 create mode 100755 tests/qemu-iotests/096
 create mode 100644 tests/qemu-iotests/096.out
 create mode 100755 tests/qemu-iotests/117
 create mode 100644 tests/qemu-iotests/117.out

-- 
2.1.0