haraldwolff/qemu-patch-raspberry4
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block: Expect graph changes in bdrv_parent_drained_begin/end

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The .drained_begin/end callbacks can (directly or indirectly via
aio_poll()) cause block nodes to be removed or the current BdrvChild to
point to a different child node.

Use QLIST_FOREACH_SAFE() to make sure we don't access invalid
BlockDriverStates or accidentally continue iterating the parents of the
new child node instead of the node we actually came from.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2017-11-29 11:25:10 +01:00
parent 0a3e155f3f
commit 02d213009d
1 changed files with 4 additions and 4 deletions
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8
block/io.c
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@ -42,9 +42,9 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
void bdrv_parent_drained_begin(BlockDriverState *bs)
{
BdrvChild *c;
BdrvChild *c, *next;
QLIST_FOREACH(c, &bs->parents, next_parent) {
QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
if (c->role->drained_begin) {
c->role->drained_begin(c);
}
@ -53,9 +53,9 @@ void bdrv_parent_drained_begin(BlockDriverState *bs)
void bdrv_parent_drained_end(BlockDriverState *bs)
{
BdrvChild *c;
BdrvChild *c, *next;
QLIST_FOREACH(c, &bs->parents, next_parent) {
QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
if (c->role->drained_end) {
c->role->drained_end(c);
}