[Qemu-devel] [PATCH V3 7/7] block: Add backing file loop check in qed_change_backing_file()

[Xu Wang <cngesaint@gmail.com>]

Add backing file loop check before execute change backing file for
qed format.

Signed-off-by: Xu Wang <cngesaint@gmail.com>
---
 block/qed.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/block/qed.c b/block/qed.c
index f767b05..79c2875 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1468,6 +1468,13 @@ static int bdrv_qed_change_backing_file(BlockDriverState *bs,
         return -ENOTSUP;
     }
 
+    /* Check if loop exists in backing files chain after changed */
+    if (bdrv_backing_file_loop_check(bs->filename,
+                                     bs->drv ? bs->drv->format_name : NULL,
+                                     backing_file, backing_fmt)) {
+        return -EIO;
+    }
+
     memcpy(&new_header, &s->header, sizeof(new_header));
 
     new_header.features &= ~(QED_F_BACKING_FILE |
-- 
1.8.1.4