ubifs: Implement UBIFS_FLG_DOUBLE_HASH
This feature flag indicates that all directory entry nodes have a 32bit
cookie set and therefore UBIFS is allowed to perform lookups by hash.
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 1bba4c8..74ae2de 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -1930,6 +1930,9 @@ int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,
int err;
const struct ubifs_dent_node *dent = node;
+ if (!c->double_hash)
+ return -EOPNOTSUPP;
+
/*
* We assume that in most of the cases there are no name collisions and
* 'ubifs_tnc_lookup()' returns us the right direntry.
