vpc: Return 0 from vpc_co_create() on success

blockdev_create_run() directly uses .bdrv_co_create()'s return value as
the job's return value.  Jobs must return 0 on success, not just any
nonnegative value.  Therefore, using blockdev-create for VPC images may
currently fail as the vpc driver may return a positive integer.

Because there is no point in returning a positive integer anywhere in
the block layer (all non-negative integers are generally treated as
complete success), we probably do not want to add more such cases.
Therefore, fix this problem by making the vpc driver always return 0 in
case of success.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 1a37e3124407b5a145d44478d3ecbdb89c63789f)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/block/vpc.c b/block/vpc.c
index d4776ee8a5229ff43e8fb4fb6e0f38c4ec348770..3a88e28e2be18553ff50a9b5c0704c514e5456e4 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -885,6 +885,7 @@ static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
         goto fail;
     }
 
+    ret = 0;
  fail:
     return ret;
 }
@@ -908,7 +909,7 @@ static int create_fixed_disk(BlockBackend *blk, uint8_t *buf,
         return ret;
     }
 
-    return ret;
+    return 0;
 }
 
 static int calculate_rounded_image_size(BlockdevCreateOptionsVpc *vpc_opts,