On 08.11.22 13:37, Kevin Wolf wrote:
Polling during bdrv_drained_end() can be problematic (and in the future,
we may get cases for bdrv_drained_begin() where polling is forbidden,
and we don't care about already in-flight requests, but just want to
prevent new requests from arriving).

The .bdrv_drained_begin/end callbacks running in a coroutine is the only
reason why we have to do this polling, so make them non-coroutine
callbacks again. None of the callers actually yield any more.

This means that bdrv_drained_end() effectively doesn't poll any more,
even if AIO_WAIT_WHILE() loops are still there (their condition is false
from the beginning). This is generally not a problem, but in
test-bdrv-drain, some additional explicit aio_poll() calls need to be
added because the test case wants to verify the final state after BHs
have executed.

Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
  include/block/block_int-common.h | 10 ++++---
  block.c                          |  4 +--
  block/io.c                       | 49 +++++---------------------------
  block/qed.c                      |  4 +--
  block/throttle.c                 |  6 ++--
  tests/unit/test-bdrv-drain.c     | 18 ++++++------
  6 files changed, 30 insertions(+), 61 deletions(-)

As the others have already suggested, I’d too drop the _co_ in qed and throttle, and the coroutine_fn in throttle.  With that done:

Reviewed-by: Hanna Reitz <hre...@redhat.com>


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