ocfs2/dlm: Activate dlm->master_hash for master list entries

With this patch, the mles are stored in a hash and not a simple list.
This should improve the mle lookup time when the number of outstanding
masteries is large.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 43 insertions, 18 deletions

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index ec6da3c37dc8..804558174a77 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -69,7 +69,8 @@ static int dlm_do_assert_master(struct dlm_ctxt *dlm,
 static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
 
 static inline void __dlm_mle_name(struct dlm_master_list_entry *mle,
-                                  unsigned char **name, unsigned int *namelen)
+                                  unsigned char **name, unsigned int *namelen,
+                                  unsigned int *namehash)
 {
         BUG_ON(mle->type != DLM_MLE_BLOCK &&
                mle->type != DLM_MLE_MASTER &&
@@ -78,9 +79,13 @@ static inline void __dlm_mle_name(struct dlm_master_list_entry *mle,
         if (mle->type != DLM_MLE_MASTER) {
                 *name = mle->u.mlename.name;
                 *namelen = mle->u.mlename.len;
+                if (namehash)
+                        *namehash = mle->u.mlename.hash;
         } else {
                 *name  = (unsigned char *)mle->u.mleres->lockname.name;
                 *namelen = mle->u.mleres->lockname.len;
+                if (namehash)
+                        *namehash = mle->u.mleres->lockname.hash;
         }
 }
 
@@ -95,7 +100,7 @@ static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
         if (dlm != mle->dlm)
                 return 0;
 
-        __dlm_mle_name(mle, &mlename, &mlelen);
+        __dlm_mle_name(mle, &mlename, &mlelen, NULL);
 
         if (namelen != mlelen || memcmp(name, mlename, namelen) != 0)
                 return 0;
@@ -294,7 +299,7 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle,
 
         mle->dlm = dlm;
         mle->type = type;
-        INIT_LIST_HEAD(&mle->list);
+        INIT_HLIST_NODE(&mle->master_hash_node);
         INIT_LIST_HEAD(&mle->hb_events);
         memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
         spin_lock_init(&mle->spinlock);
@@ -317,6 +322,7 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle,
                 BUG_ON(!name);
                 memcpy(mle->u.mlename.name, name, namelen);
                 mle->u.mlename.len = namelen;
+                mle->u.mlename.hash = dlm_lockid_hash(name, namelen);
         }
 
         /* copy off the node_map and register hb callbacks on our copy */
@@ -334,15 +340,21 @@ void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
         assert_spin_locked(&dlm->spinlock);
         assert_spin_locked(&dlm->master_lock);
 
-        if (!list_empty(&mle->list))
-                list_del_init(&mle->list);
+        if (!hlist_unhashed(&mle->master_hash_node))
+                hlist_del_init(&mle->master_hash_node);
 }
 
 void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle)
 {
+        struct hlist_head *bucket;
+        unsigned char *mname;
+        unsigned int mlen, hash;
+
         assert_spin_locked(&dlm->master_lock);
 
-        list_add(&mle->list, &dlm->master_list);
+        __dlm_mle_name(mle, &mname, &mlen, &hash);
+        bucket = dlm_master_hash(dlm, hash);
+        hlist_add_head(&mle->master_hash_node, bucket);
 }
 
 /* returns 1 if found, 0 if not */
@@ -351,10 +363,17 @@ static int dlm_find_mle(struct dlm_ctxt *dlm,
                         char *name, unsigned int namelen)
 {
         struct dlm_master_list_entry *tmpmle;
+        struct hlist_head *bucket;
+        struct hlist_node *list;
+        unsigned int hash;
 
         assert_spin_locked(&dlm->master_lock);
 
-        list_for_each_entry(tmpmle, &dlm->master_list, list) {
+        hash = dlm_lockid_hash(name, namelen);
+        bucket = dlm_master_hash(dlm, hash);
+        hlist_for_each(list, bucket) {
+                tmpmle = hlist_entry(list, struct dlm_master_list_entry,
+                                     master_hash_node);
                 if (!dlm_mle_equal(dlm, tmpmle, name, namelen))
                         continue;
                 dlm_get_mle(tmpmle);
@@ -428,23 +447,20 @@ static void dlm_mle_release(struct kref *kref)
 {
         struct dlm_master_list_entry *mle;
         struct dlm_ctxt *dlm;
+        unsigned char *mname;
+        unsigned int mlen;
 
         mlog_entry_void();
 
         mle = container_of(kref, struct dlm_master_list_entry, mle_refs);
         dlm = mle->dlm;
 
-        if (mle->type != DLM_MLE_MASTER) {
-                mlog(0, "calling mle_release for %.*s, type %d\n",
-                     mle->u.mlename.len, mle->u.mlename.name, mle->type);
-        } else {
-                mlog(0, "calling mle_release for %.*s, type %d\n",
-                     mle->u.mleres->lockname.len,
-                     mle->u.mleres->lockname.name, mle->type);
-        }
         assert_spin_locked(&dlm->spinlock);
         assert_spin_locked(&dlm->master_lock);
 
+        __dlm_mle_name(mle, &mname, &mlen, NULL);
+        mlog(0, "Releasing mle for %.*s, type %d\n", mlen, mname, mle->type);
+
         /* remove from list if not already */
         __dlm_unlink_mle(dlm, mle);
 
@@ -1342,7 +1358,7 @@ static int dlm_do_master_request(struct dlm_lock_resource *res,
 
         BUG_ON(mle->type == DLM_MLE_MIGRATION);
 
-        __dlm_mle_name(mle, &mlename, &mlenamelen);
+        __dlm_mle_name(mle, &mlename, &mlenamelen, NULL);
 
         request.namelen = (u8)mlenamelen;
         memcpy(request.name, mlename, request.namelen);
@@ -3286,8 +3302,11 @@ static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
 
 void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
 {
-        struct dlm_master_list_entry *mle, *next;
+        struct dlm_master_list_entry *mle;
         struct dlm_lock_resource *res;
+        struct hlist_head *bucket;
+        struct hlist_node *list;
+        unsigned int i;
 
         mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
 top:
@@ -3295,7 +3314,12 @@ top:
 
         /* clean the master list */
         spin_lock(&dlm->master_lock);
-        list_for_each_entry_safe(mle, next, &dlm->master_list, list) {
+        for (i = 0; i < DLM_HASH_BUCKETS; i++) {
+                bucket = dlm_master_hash(dlm, i);
+                hlist_for_each(list, bucket) {
+                        mle = hlist_entry(list, struct dlm_master_list_entry,
+                                          master_hash_node);
+
                 BUG_ON(mle->type != DLM_MLE_BLOCK &&
                        mle->type != DLM_MLE_MASTER &&
                        mle->type != DLM_MLE_MIGRATION);
@@ -3351,6 +3375,7 @@ top:
                 /* this may be the last reference */
                 __dlm_put_mle(mle);
         }
+        }
         spin_unlock(&dlm->master_lock);
 }