Am 08.03.2019 um 16:48 hat Sergio Lopez geschrieben: > While child_job_drained_begin() calls to job_pause(), the job doesn't > actually transition between states until it runs again and reaches a > pause point. This means bdrv_drained_begin() may return with some jobs > using the node still having 'busy == true'. > > As a consequence, block_job_detach_aio_context() may get into a > deadlock, waiting for the job to be actually paused, while the coroutine > servicing the job is yielding and doesn't get the opportunity to get > scheduled again. This situation can be reproduced by issuing a > 'block-commit' immediately followed by a 'device_del'. > > To ensure bdrv_drained_begin() only returns when the jobs have been > paused, we change mirror_drained_poll() to only confirm it's quiesced > when job->paused == true and there aren't any in-flight requests, except > if we reached that point by a drained section initiated by the > mirror/commit job itself. > > The other block jobs shouldn't need any changes, as the default > drained_poll() behavior is to only confirm it's quiesced if the job is > not busy or completed. > > Signed-off-by: Sergio Lopez <s...@redhat.com>
Thanks, applied to the block branch. Kevin
