From fe5258a503a87e69be37c9ac48799e293809386e Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 6 Sep 2018 17:43:49 +0200 Subject: [PATCH] block-backend: Add .drained_poll callback A bdrv_drain operation must ensure that all parents are quiesced, this includes BlockBackends. Otherwise, callbacks called by requests that are completed on the BDS layer, but not quite yet on the BlockBackend layer could still create new requests. Signed-off-by: Kevin Wolf Reviewed-by: Fam Zheng Reviewed-by: Max Reitz --- block/block-backend.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index 14a1b7ac6a..4e7d08ac3a 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -121,6 +121,7 @@ static void blk_root_inherit_options(int *child_flags, QDict *child_options, abort(); } static void blk_root_drained_begin(BdrvChild *child); +static bool blk_root_drained_poll(BdrvChild *child); static void blk_root_drained_end(BdrvChild *child); static void blk_root_change_media(BdrvChild *child, bool load); @@ -294,6 +295,7 @@ static const BdrvChildRole child_root = { .get_parent_desc = blk_root_get_parent_desc, .drained_begin = blk_root_drained_begin, + .drained_poll = blk_root_drained_poll, .drained_end = blk_root_drained_end, .activate = blk_root_activate, @@ -2189,6 +2191,13 @@ static void blk_root_drained_begin(BdrvChild *child) } } +static bool blk_root_drained_poll(BdrvChild *child) +{ + BlockBackend *blk = child->opaque; + assert(blk->quiesce_counter); + return !!blk->in_flight; +} + static void blk_root_drained_end(BdrvChild *child) { BlockBackend *blk = child->opaque; -- GitLab