When invoking drive-mirror in absolute-paths mode, the target's backing
BDS is assigned to it in mirror_complete(). The current logic only does
so if the target does not have that backing BDS already; but it actually
cannot have a backing BDS at all (the BDS is opened with O_NO_BACKING in
qmp_drive_mirror()), so just assert that and assign the new backing BDS
unconditionally.
Signed-off-by: Max Reitz
---
block/mirror.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 301ba92..4ece624 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -888,9 +888,9 @@ static void mirror_complete(BlockJob *job, Error **errp)
if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
BlockDriverState *backing = s->is_none_mode ? src : s->base;
-if (backing_bs(target) != backing) {
-bdrv_set_backing_hd(target, backing);
-}
+
+assert(!target->backing);
+bdrv_set_backing_hd(target, backing);
}
s->should_complete = true;
--
2.10.2
