[Qemu-devel] [PATCH V6 2/5] qemu-img: Add infinite loop checking in bdrv_new_open()

[Xu Wang]

Every image should be checked if there is infinite loop in backing
file chain before open it. So infinite loop check was added into
bdrv_new_open(). If @filename is opened without the flag
BDRV_O_NO_BACKING, the infinite loop check should be called.

Signed-off-by: Xu Wang <address@hidden>
---
 qemu-img.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/qemu-img.c b/qemu-img.c
index d5ec45b..3af7996 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -281,6 +281,14 @@ static BlockDriverState *bdrv_new_open(const char 
*filename,
         drv = NULL;
     }
 
+    /* check backing file loop if the whole chain need to be opened */
+    if (!(flags & BDRV_O_NO_BACKING) &&
+        !bdrv_backing_chain_okay(filename, fmt)) {
+        error_report("bdrv_new_open: Open %s failed. There is loop exists "
+                     "in the backing chain", filename);
+        goto fail;
+    }
+
     ret = bdrv_open(bs, filename, NULL, flags, drv, &local_err);
     if (ret < 0) {
         error_report("Could not open '%s': %s", filename,
-- 
1.8.1.4