On Thu, Dec 05, 2013 at 08:02:50PM +0800, Wenchao Xia wrote:
+restore_refcount:
+ if (qcow2_update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1)
+ < 0 && errp) {
+ /* Nothing can be done now, need image check later */
+ error_setg(&err, "%s\nqcow2: Error in restoring refcount in snapshot",
+ error_get_pretty(*errp));
+ error_free(*errp);
+ *errp = NULL;
+ error_propagate(errp, err);
+ }
We get here if writing the new snapshot list failed. If
qcow2_update_snapshot_refcount(..., -1) also fails I think we should
skip qcow2_free_clusters() below. We don't know the exact state of the
disk image anymore - better to leak clusters than to have a dangling
reference.