1 files changed, 1 insertions, 1 deletions
diff --git a/block/backup.c b/block/backup.c
index 7978ae2e50..d0b02255ce 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -307,7 +307,7 @@ static void coroutine_fn backup_run(void *opaque)
                                 BACKUP_SECTORS_PER_CLUSTER - i, &n);
                     i += n;
 
-                    if (alloced == 1) {
+                    if (alloced == 1 || n == 0) {
                         break;
                     }
                 }