[Qemu-devel] [PATCH 3/3] block: Catch !bs->drv in bdrv_check()

[Max Reitz <mreitz@redhat.com>]

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 <mreitz@redhat.com>
---
 block.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block.c b/block.c
index 8cf519b..2b470d8 100644
--- a/block.c
+++ b/block.c
@@ -2203,6 +2203,9 @@ 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;
     }
-- 
2.0.3