blockdev: fix missed target unref for drive-backup

If the bitmap can't be used for whatever reason, we skip putting down the reference. Fix that. In practice, this means that if you attempt to gracefully exit QEMU after a backup command being rejected, bdrv_close_all will fail and tell you some unpleasant things via assert(). Reported-by: aihua liang <[email protected]> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916 Signed-off-by: John Snow <[email protected]> Reviewed-by: Kevin Wolf <[email protected]> Signed-off-by: Kevin Wolf <[email protected]>
simpz · Jun 4, 2019 · 4da26f1 · 4da26f1
1 parent ac6fb43
commit 4da26f1
Showing 1 changed file with 6 additions and 7 deletions.
diff --git a/blockdev.c b/blockdev.c
@@ -3546,20 +3546,18 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
     if (set_backing_hd) {
         bdrv_set_backing_hd(target_bs, source, &local_err);
         if (local_err) {
-            bdrv_unref(target_bs);
-            goto out;
+            goto unref;
         }
     }
 
     if (backup->has_bitmap) {
         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
         if (!bmap) {
             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
-            bdrv_unref(target_bs);
-            goto out;
+            goto unref;
         }
         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_DEFAULT, errp)) {
-            goto out;
+            goto unref;
         }
     }
     if (!backup->auto_finalize) {
@@ -3573,12 +3571,13 @@ static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
                             backup->sync, bmap, backup->compress,
                             backup->on_source_error, backup->on_target_error,
                             job_flags, NULL, NULL, txn, &local_err);
-    bdrv_unref(target_bs);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-        goto out;
+        goto unref;
     }
 
+unref:
+    bdrv_unref(target_bs);
 out:
     aio_context_release(aio_context);
     return job;