diff mbox

[V6,4/5] block: Add backing file loop check in change_backing_file()

Message ID 1383707361-19580-5-git-send-email-gesaint@linux.vnet.ibm.com
State New
Headers show

Commit Message

Xu Wang Nov. 6, 2013, 3:09 a.m. UTC 
Backing file loop should be checked before calling change_backing_
file(). If loop appeared, this calling should be stopped and an
error printed.

Signed-off-by: Xu Wang <gesaint@linux.vnet.ibm.com>
---
 block.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox

Patch

diff --git a/block.c b/block.c
index 8423e80..cb50bfd 100644
--- a/block.c
+++ b/block.c
@@ -2083,6 +2083,11 @@  int bdrv_change_backing_file(BlockDriverState *bs,
         return -EINVAL;
     }
 
+    /* Check if loop exists in backing files chain after change */
+    if (!bdrv_new_chain_okay(bs->filename, backing_file, backing_fmt)) {
+        return -EIO;
+    }
+
     if (drv->bdrv_change_backing_file != NULL) {
         ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
     } else {