block: allow bdrv_unref() to be passed NULL pointers
commit9a4d5ca60772e09d0cbac01f1b4778aa68e00eaa
authorJeff Cody <jcody@redhat.com>
Wed, 23 Jul 2014 21:22:57 +0000 (23 17:22 -0400)
committerKevin Wolf <kwolf@redhat.com>
Fri, 15 Aug 2014 13:07:14 +0000 (15 15:07 +0200)
tree2d42ce46e2fcc8a311d8ddc519494130b587b28e
parent58803ce74f986785badfb2ef0f630e1cd97f52e5
block: allow bdrv_unref() to be passed NULL pointers

If bdrv_unref() is passed a NULL BDS pointer, it is safe to
exit with no operation.  This will allow cleanup code to blindly
call bdrv_unref() on a BDS that has been initialized to NULL.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block.c