While we cannot represent the latency-ns option in a filename, it is not
a strong option so not being able to should not stop us from generating
a filename nonetheless.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/null.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/null.c b/block/null.c
index 1c56a0ef01..a322929478 100644
--- a/block/null.c
+++ b/block/null.c
@@ -248,7 +248,8 @@ static void null_refresh_filename(BlockDriverState *bs)
     {
         /* These options can be ignored */
         if (strcmp(qdict_entry_key(e), "filename") &&
-            strcmp(qdict_entry_key(e), "driver"))
+            strcmp(qdict_entry_key(e), "driver") &&
+            strcmp(qdict_entry_key(e), NULL_OPT_LATENCY))
         {
             return;
         }
-- 
2.17.1