block: Make bdrv_root_attach_child() unref child_bs on failure
A consequence of the previous patch is that bdrv_attach_child()
transfers the reference to child_bs from the caller to parent_bs,
which will drop it on bdrv_close() or when someone calls
bdrv_unref_child().
But this only happens when bdrv_attach_child() succeeds. If it fails
then the caller is responsible for dropping the reference to child_bs.
This patch makes bdrv_attach_child() take the reference also when
there is an error, freeing the caller for having to do it.
A similar situation happens with bdrv_root_attach_child(), so the
changes on this patch affect both functions.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20dfb3d9ccec559cdd1a9690146abad5d204a186.1557754872.git.berto@igalia.com
[mreitz: Removed now superfluous BdrvChild * variable in
bdrv_open_child()]
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/blockjob.c b/blockjob.c
index 9ca942b..cc5f18e 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -204,6 +204,7 @@
{
BdrvChild *c;
+ bdrv_ref(bs);
c = bdrv_root_attach_child(bs, name, &child_job, perm, shared_perm,
job, errp);
if (c == NULL) {
@@ -211,7 +212,6 @@
}
job->nodes = g_slist_prepend(job->nodes, c);
- bdrv_ref(bs);
bdrv_op_block_all(bs, job->blocker);
return 0;
