dm cache: return -EINVAL if the user specifies unknown cache policy

Return -EINVAL when the specified cache policy is unknown rather than
returning -ENOMEM.

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

2 files changed, 9 insertions, 8 deletions

diff --git a/drivers/md/dm-cache-policy.c b/drivers/md/dm-cache-policy.c
index 21c03c570c06..d80057968407 100644
--- a/drivers/md/dm-cache-policy.c
+++ b/drivers/md/dm-cache-policy.c
@@ -119,13 +119,13 @@ struct dm_cache_policy *dm_cache_policy_create(const char *name,
         type = get_policy(name);
         if (!type) {
                 DMWARN("unknown policy type");
-                return NULL;
+                return ERR_PTR(-EINVAL);
         }
 
         p = type->create(cache_size, origin_size, cache_block_size);
         if (!p) {
                 put_policy(type);
-                return NULL;
+                return ERR_PTR(-ENOMEM);
         }
         p->private = type;
 
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 50afdf72285b..81fe85757585 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1879,14 +1879,15 @@ static int set_config_values(struct cache *cache, int argc, const char **argv)
 static int create_cache_policy(struct cache *cache, struct cache_args *ca,
                                char **error)
 {
-        cache->policy = dm_cache_policy_create(ca->policy_name,
-                                               cache->cache_size,
-                                               cache->origin_sectors,
-                                               cache->sectors_per_block);
-        if (!cache->policy) {
+        struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name,
+                                                           cache->cache_size,
+                                                           cache->origin_sectors,
+                                                           cache->sectors_per_block);
+        if (IS_ERR(p)) {
                 *error = "Error creating cache's policy";
-                return -ENOMEM;
+                return PTR_ERR(p);
         }
+        cache->policy = p;
 
         return 0;
 }