[Qemu-devel] [PATCH 00/20] block: Implement writethrough in BlockBackend

[Kevin Wolf]

I already sent (and merged) patches that are meant to prevent users from
setting the writethrough option on non-root nodes, where we won't be able to
support the feature in the long term because we discovered that writethrough
mode only makes sense as a BlockBackend feature. The intention was to allow
moving the feature where it belongs in the following release.

However, moving the feature involves another few changes in behaviour in some
corner cases (most of which became only possible with patches after 2.5), so it
seems to be actually preferable to do the full thing now instead of having
behaviour changes in two consecutive releases.

This series removes (or is supposed to remove, at least) all traces of
writethrough handling from the BlockDriverState layer and implements it in
BlockBackend instead.

Kevin Wolf (20):
  block: Add bdrv_parse_cache_mode()
  qemu-nbd: Call blk_set_enable_write_cache() explicitly
  qemu-io: Call blk_set_enable_write_cache() explicitly
  qemu-img: Expand all BDRV_O_FLAGS uses
  qemu-img: Call blk_set_enable_write_cache() explicitly
  xen_disk: Call blk_set_enable_write_cache() explicitly
  block: blockdev_init(): Call blk_set_enable_write_cache() explicitly
  block: Always set writeback mode in blk_new_open()
  block: Handle flush error in bdrv_pwrite_sync()
  block: Move enable_write_cache to BB level
  block/qapi: Use blk_enable_write_cache()
  block: Introduce bdrv_co_writev_flags()
  iscsi: Support BDRV_REQ_FUA
  nbd: Support BDRV_REQ_FUA
  raw: Support BDRV_REQ_FUA
  block: Use bdrv_parse_cache_mode() in drive_init()
  qemu-io: Use bdrv_parse_cache_mode() in reopen_f()
  block: Remove bdrv_parse_cache_flags()
  block: Remove BDRV_O_CACHE_WB
  block: Remove bdrv_(set_)enable_write_cache()

 block.c                       |  78 +++++---------------------------
 block/backup.c                |   1 -
 block/block-backend.c         |  45 ++++++++++--------
 block/io.c                    |  15 ++++--
 block/iscsi.c                 |  24 +++-------
 block/mirror.c                |   1 -
 block/nbd-client.c            |  13 +++---
 block/nbd-client.h            |   2 +-
 block/nbd.c                   |  26 +++++++++--
 block/parallels.c             |   3 +-
 block/qapi.c                  |   7 +--
 block/qcow.c                  |   3 +-
 block/qcow2.c                 |   9 ++--
 block/qed.c                   |   3 +-
 block/raw_bsd.c               |  11 +++--
 block/sheepdog.c              |   5 +-
 block/vdi.c                   |   3 +-
 block/vhdx.c                  |   3 +-
 block/vmdk.c                  |   8 ++--
 block/vpc.c                   |   3 +-
 block/vvfat.c                 |   3 +-
 blockdev.c                    |  35 ++++++--------
 hw/block/xen_disk.c           |   5 +-
 include/block/block.h         |   8 ++--
 include/block/block_int.h     |   8 ++--
 include/block/qapi.h          |   3 +-
 qemu-img.c                    |  84 ++++++++++++++++++++--------------
 qemu-io-cmds.c                |  13 +++++-
 qemu-io.c                     |  21 +++++----
 qemu-nbd.c                    |   5 +-
 tests/qemu-iotests/051        |   2 +-
 tests/qemu-iotests/051.pc.out |  10 ++--
 tests/qemu-iotests/142        |  19 +++++---
 tests/qemu-iotests/142.out    | 103 ++++++++++++++++++++++++++++--------------
 34 files changed, 304 insertions(+), 278 deletions(-)

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1.8.3.1