block: Move node without parents to main AioContext

A node should only be in a non-default AioContext if a user is attached
to it that requires this. When the last parent of a node is gone, it can
move back to the main AioContext.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/block.c b/block.c
index 7d9ed1a724..6830f2d940 100644
--- a/block.c
+++ b/block.c
@@ -2235,6 +2235,10 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
         bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
         bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort);
         bdrv_set_perm(old_bs, perm, shared_perm);
+
+        /* When the parent requiring a non-default AioContext is removed, the
+         * node moves back to the main AioContext */
+        bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL);
     }
 
     if (new_bs) {