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[Qemu-devel] [PATCH 08/14] block-backend: Add .drained_poll callback
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 08/14] block-backend: Add .drained_poll callback |
Date: |
Fri, 7 Sep 2018 18:15:14 +0200 |
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 <address@hidden>
---
block/block-backend.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/block/block-backend.c b/block/block-backend.c
index fa120630be..efa8d8011c 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,
@@ -2191,6 +2193,13 @@ 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;
--
2.13.6
- [Qemu-devel] [PATCH 05/14] test-bdrv-drain: Test AIO_WAIT_WHILE() in completion callback, (continued)
[Qemu-devel] [PATCH 11/14] mirror: Fix potential use-after-free in active commit, Kevin Wolf, 2018/09/07
[Qemu-devel] [PATCH 08/14] block-backend: Add .drained_poll callback,
Kevin Wolf <=
[Qemu-devel] [PATCH 10/14] block-backend: Decrease in_flight only after callback, Kevin Wolf, 2018/09/07
[Qemu-devel] [PATCH 13/14] block: Remove aio_poll() in bdrv_drain_poll variants, Kevin Wolf, 2018/09/07
[Qemu-devel] [PATCH 09/14] block-backend: Fix potential double blk_delete(), Kevin Wolf, 2018/09/07
[Qemu-devel] [PATCH 12/14] blockjob: Lie better in child_job_drained_poll(), Kevin Wolf, 2018/09/07
[Qemu-devel] [PATCH 14/14] test-bdrv-drain: Test nested poll in bdrv_drain_poll_top_level(), Kevin Wolf, 2018/09/07