Allow block backends to poll their devices/users to check if they have
been quiesced when entering a drained section.
This will be used in the next patch to wait for the NBD server to be
completely quiesced.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Sergio Lopez <slp@redhat.com>
Message-Id: <
20210602060552.17433-2-slp@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
static bool blk_root_drained_poll(BdrvChild *child)
{
BlockBackend *blk = child->opaque;
+ bool busy = false;
assert(blk->quiesce_counter);
- return !!blk->in_flight;
+
+ if (blk->dev_ops && blk->dev_ops->drained_poll) {
+ busy = blk->dev_ops->drained_poll(blk->dev_opaque);
+ }
+ return busy || !!blk->in_flight;
}
static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter)
* Runs when the backend's last drain request ends.
*/
void (*drained_end)(void *opaque);
+ /*
+ * Is the device still busy?
+ */
+ bool (*drained_poll)(void *opaque);
} BlockDevOps;
/* This struct is embedded in (the private) BlockBackend struct and contains