diff mbox

[v8,1/5] block: check for existing device IDs in external_snapshot_prepare()

Message ID 7d4082df3a290000a9d17b1337c32ab936335e20.1445861886.git.berto@igalia.com
State New
Headers show

Commit Message

Alberto Garcia Oct. 26, 2015, 12:27 p.m. UTC 
The 'snapshot-node-name' parameter of blockdev-snapshot-sync allows
setting the node name of the image that is going to be created.

Before creating the image, external_snapshot_prepare() checks that the
name is not already being used. The check is however incomplete since
it only considers existing node names, but node names must not clash
with device IDs either because they share the same namespace.

If the user attempts to create a snapshot using the name of an
existing device for the 'snapshot-node-name' parameter the operation
will eventually fail, but only after the new image has been created.

This patch replaces bdrv_find_node() with bdrv_lookup_bs() to extend
the check to existing device IDs, and thus detect possible name
clashes before the new image is created.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
---
 blockdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/blockdev.c b/blockdev.c
index 18712d2..8084b0d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1568,8 +1568,9 @@  static void external_snapshot_prepare(BlkTransactionState *common,
         return;
     }
 
-    if (has_snapshot_node_name && bdrv_find_node(snapshot_node_name)) {
-        error_setg(errp, "New snapshot node name already existing");
+    if (has_snapshot_node_name &&
+        bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
+        error_setg(errp, "New snapshot node name already in use");
         return;
     }