From 92a9a816dd93a361ad2e0751e503c5e12accf38b Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 10 Oct 2018 20:22:03 +0100 Subject: [PATCH 37/49] block-backend: Add .drained_poll callback RH-Author: Kevin Wolf Message-id: <20181010202213.7372-25-kwolf@redhat.com> Patchwork-id: 82614 O-Subject: [RHEL-8 qemu-kvm PATCH 34/44] block-backend: Add .drained_poll callback Bugzilla: 1637976 RH-Acked-by: Max Reitz RH-Acked-by: John Snow RH-Acked-by: Thomas Huth 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 (cherry picked from commit fe5258a503a87e69be37c9ac48799e293809386e) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/block-backend.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index 3554b7e..dffc6f0 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, @@ -2198,6 +2200,13 @@ 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; -- 1.8.3.1