[PATCH] Clean up ocfs2 hash probe and make it faster

Signed-Off-By: Daniel Phillips <phillips@google.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index a818fde244763aef7f0db52a135822435883f2b1..595b1c7cbd1fdef69f47e33ee1c645c0c85d8dff 100644 (file)
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -103,28 +103,27 @@ struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
                                                unsigned int len,
                                                unsigned int hash)
 {
-       struct hlist_node *iter;
-       struct dlm_lock_resource *tmpres=NULL;
        struct hlist_head *bucket;
+       struct hlist_node *list;
 
        mlog_entry("%.*s\n", len, name);
 
        assert_spin_locked(&dlm->spinlock);
 
-       bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
-
-       /* check for pre-existing lock */
-       hlist_for_each(iter, bucket) {
-               tmpres = hlist_entry(iter, struct dlm_lock_resource, hash_node);
-               if (tmpres->lockname.len == len &&
-                   memcmp(tmpres->lockname.name, name, len) == 0) {
-                       dlm_lockres_get(tmpres);
-                       break;
-               }
-
-               tmpres = NULL;
+       bucket = dlm->lockres_hash + full_name_hash(name, len) % DLM_HASH_BUCKETS;
+       hlist_for_each(list, bucket) {
+               struct dlm_lock_resource *res = hlist_entry(list,
+                       struct dlm_lock_resource, hash_node);
+               if (res->lockname.name[0] != name[0])
+                       continue;
+               if (unlikely(res->lockname.len != len))
+                       continue;
+               if (memcmp(res->lockname.name + 1, name + 1, len - 1))
+                       continue;
+               dlm_lockres_get(res);
+               return res;
        }
-       return tmpres;
+       return NULL;
 }
 
 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,