block: Avoid printing NULL string in error messages

Even for nodes that have a BlockBackend attached, bdrv_get_parent_name()
can return NULL if the BB is anonymous (e.g. it belongs to a block job
or a device that was created with a drive=<node-name> option).

Remove the information from the error message. The user probably knows
already why the node is still in use.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

diff --git a/blockdev.c b/blockdev.c
index 405145ae95fcac08f7b6b418b927a32bae306bc6..17c2671c5e2419f9b15fe8a0679570920aa9757e 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -1803,8 +1803,7 @@ static void external_snapshot_prepare(BlkActionState *common,
     }
 
     if (bdrv_has_blk(state->new_bs)) {
-        error_setg(errp, "The snapshot is already in use by %s",
-                   bdrv_get_parent_name(state->new_bs));
+        error_setg(errp, "The snapshot is already in use");
         return;
     }
 
@@ -2532,8 +2531,7 @@ void qmp_x_blockdev_insert_medium(bool has_device, const char *device,
     }
 
     if (bdrv_has_blk(bs)) {
-        error_setg(errp, "Node '%s' is already in use by '%s'", node_name,
-                   bdrv_get_parent_name(bs));
+        error_setg(errp, "Node '%s' is already in use", node_name);
         return;
     }
 
@@ -3941,8 +3939,7 @@ void qmp_x_blockdev_del(bool has_id, const char *id,
             return;
         }
         if (bdrv_has_blk(bs)) {
-            error_setg(errp, "Node %s is in use by %s",
-                       node_name, bdrv_get_parent_name(bs));
+            error_setg(errp, "Node %s is in use", node_name);
             return;
         }
         aio_context = bdrv_get_aio_context(bs);

diff --git a/tests/qemu-iotests/085.out b/tests/qemu-iotests/085.out
index 01c78d68946cd500ac697f9f8e83daaccdb9abfc..08e4bb72187df00b3c22d37c9650d7db9ab4a63e 100644 (file)
--- a/tests/qemu-iotests/085.out
+++ b/tests/qemu-iotests/085.out
@@ -68,9 +68,9 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/
 
 === Invalid command - snapshot node used as active layer ===
 
-{"error": {"class": "GenericError", "desc": "The snapshot is already in use by virtio0"}}
-{"error": {"class": "GenericError", "desc": "The snapshot is already in use by virtio0"}}
-{"error": {"class": "GenericError", "desc": "The snapshot is already in use by virtio1"}}
+{"error": {"class": "GenericError", "desc": "The snapshot is already in use"}}
+{"error": {"class": "GenericError", "desc": "The snapshot is already in use"}}
+{"error": {"class": "GenericError", "desc": "The snapshot is already in use"}}
 
 === Invalid command - snapshot node used as backing hd ===