From: Sergio Lopez Date: Wed, 2 Jun 2021 06:05:51 +0000 (+0200) Subject: block-backend: add drained_poll X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=095cc4d0f62513d75e9bc1da37f08d9e97f267c4;p=qmiga%2Fqemu.git block-backend: add drained_poll 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 Reviewed-by: Kevin Wolf Reviewed-by: Eric Blake Signed-off-by: Sergio Lopez Message-Id: <20210602060552.17433-2-slp@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Kevin Wolf --- diff --git a/block/block-backend.c b/block/block-backend.c index 5be32c0c42..15f1ea4288 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2386,8 +2386,13 @@ static void blk_root_drained_begin(BdrvChild *child) 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) diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 880e903293..5423e3d9c6 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -66,6 +66,10 @@ typedef struct BlockDevOps { * 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