iotests: Test blockdev-reopen with iothreads and throttling

The 'throttle' block driver implements .bdrv_co_drain_end, so
blockdev-reopen will have to wait for it to complete in the polling
loop at the end of qmp_blockdev_reopen(). This makes AIO_WAIT_WHILE()
release the AioContext lock, which causes a crash if the lock hasn't
correctly been taken.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220203140534.36522-3-kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2 files changed