[Qemu-devel] [PATCH V5 6/6] block: Add infinite loop check in drive_init()

[Xu Wang <gesaint@linux.vnet.ibm.com>]

From: Xu Wang <cngesaint@gmail.com>

Backing file should be checked if there is a loop in it during image
boot. Becase if there is loop qemu would no response for a long time
and segment fault occured. So this patch would check backing file
chain if there is loop in it before open image.

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

diff --git a/blockdev.c b/blockdev.c
index b3a57e0..590193f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -695,6 +695,13 @@ DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type)
         error_report("warning: disabling copy_on_read on readonly drive");
     }
 
+    /* Add backing file loop check */
+    if (bdrv_backing_file_loop_check(file, drv ? drv->format_name : NULL,
+                                     NULL, NULL)) {
+        error_report("drive_init: backing file loop check failed!");
+        goto err;
+    }
+
     ret = bdrv_open(dinfo->bdrv, file, bs_opts, bdrv_flags, drv);
     bs_opts = NULL;
 
-- 
1.8.1.4