dm writecache: report invalid return from writecache_map helpers

If some "writecache_map_*" function returns invalid state, it is a bug.
So, we should report it and not fail silently.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 64d7a798244ab6c5e5e1a0afb8c1e6ef1d81f8b9..e89868cf7d984e2f640d7f4222056908f39a8fc9 100644 (file)
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -1545,10 +1545,13 @@ done:
                return DM_MAPIO_SUBMITTED;
 
        case WC_MAP_ERROR:
-       default:
                wc_unlock(wc);
                bio_io_error(bio);
                return DM_MAPIO_SUBMITTED;
+
+       default:
+               BUG();
+               return -1;
        }
 }