[Qemu-devel] [PULL 62/62] block: Catch !bs->drv in bdrv_check()

[Kevin Wolf]

From: Max Reitz <address@hidden>

qemu-img check calls bdrv_check() twice if the first run repaired some
inconsistencies. If the first run however again triggered corruption
prevention (on qcow2) due to very bad inconsistencies, bs->drv may be
NULL afterwards. Thus, bdrv_check() should check whether bs->drv is set.

Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
 block.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block.c b/block.c
index b3a06b8..5609313 100644
--- a/block.c
+++ b/block.c
@@ -2216,6 +2216,9 @@ bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
  */
 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
 {
+    if (bs->drv == NULL) {
+        return -ENOMEDIUM;
+    }
     if (bs->drv->bdrv_check == NULL) {
         return -ENOTSUP;
     }
-- 
1.8.3.1