[Qemu-devel] [PATCH v4 0/9] block: Fixes for bdrv_drain

[Fam Zheng]

v4: Don't miss children's children. [Paolo]

v3: Don't reuse coroutine in bdrv_aio_ioctl. [Stefan]
    Recursely call .bdrv_drain callback only. [Stefan, Paolo]
    Added Kevin's reviewed-by in other patches.

v2: Add Kevin's reviewed-by in patches 1, 2, 5-7, 9.
    Address Kevin's reviewing comments which are:
    - Explicit "ret = 0" before out label in patch 3.
    - Add missing qemu_aio_unref() in patch 4.
    - Recurse into all children in bdrv_drain in patch 8.

Previously bdrv_drain and bdrv_drain_all don't handle ioctl, flush and discard
requests (which are fundamentally the same as read and write requests that
change disk state).  Forgetting such requests leaves us in risk of violating
the invariant that bdrv_drain() callers rely on - all asynchronous requests
must have completed after bdrv_drain returns.

Enrich the tracked request types, and add tracked_request_begin/end pairs to
all three code paths. As a prerequisite, ioctl code is moved into coroutine
too.

The last two patches take care of QED's "need check" timer, so that after
bdrv_drain returns, the driver is in a consistent state.

Fam


Fam Zheng (9):
  block: Add more types for tracked request
  block: Track flush requests
  block: Track discard requests
  iscsi: Emulate commands in iscsi_aio_ioctl as iscsi_ioctl
  block: Add ioctl parameter fields to BlockRequest
  block: Emulate bdrv_ioctl with bdrv_aio_ioctl and track both
  block: Drop BlockDriver.bdrv_ioctl
  block: Introduce BlockDriver.bdrv_drain callback
  qed: Implement .bdrv_drain

 block/io.c                | 150 +++++++++++++++++++++++++++++++++++++++-------
 block/iscsi.c             |  73 +++++++++++-----------
 block/qed.c               |  13 ++++
 block/raw-posix.c         |   8 ---
 block/raw_bsd.c           |   6 --
 include/block/block.h     |  16 +++--
 include/block/block_int.h |  17 +++++-
 7 files changed, 208 insertions(+), 75 deletions(-)

-- 
2.4.3