[Qemu-devel] [PATCH V7 2/4] block: Add check infinite loop in bdrv_img_create()

[Xu Wang]

Backing file loop should be checked before qemu-img create command
execution. If loop is found, qemu-img create should be stopped and
an error printed.

Signed-off-by: Xu Wang <gesa...@linux.vnet.ibm.com>
---
 block.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 3c43179..c2ed6ef 100644
--- a/block.c
+++ b/block.c
@@ -4629,15 +4629,16 @@ void bdrv_img_create(const char *filename, const char 
*fmt,
     }
 
     backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
+    backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
     if (backing_file && backing_file->value.s) {
-        if (!strcmp(filename, backing_file->value.s)) {
-            error_setg(errp, "Error: Trying to create an image with the "
-                             "same filename as the backing file");
+        if (!bdrv_backing_chain_okay(backing_file->value.s,
+                                     backing_fmt->value.s, filename)) {
+            error_setg(errp, "bdrv_img_create: loop exists, "
+                             "image create failed");
             goto out;
         }
     }
 
-    backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
     if (backing_fmt && backing_fmt->value.s) {
         backing_drv = bdrv_find_format(backing_fmt->value.s);
         if (!backing_drv) {
-- 
1.8.1.4