ocfs2: calculate lockid hash values outside of the spinlock

Fixes a performance bug - pointed out by Andrew.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

4 files changed, 30 insertions, 19 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 1c05d485e019..3b675368762e 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -39,6 +39,9 @@
 
 #define DLM_HASH_BUCKETS     (PAGE_SIZE / sizeof(struct hlist_head))
 
+/* Intended to make it easier for us to switch out hash functions */
+#define dlm_lockid_hash(_n, _l) full_name_hash(_n, _l)
+
 enum dlm_ast_type {
         DLM_AST = 0,
         DLM_BAST,
@@ -694,7 +697,8 @@ void __dlm_insert_lockres(struct dlm_ctxt *dlm,
                           struct dlm_lock_resource *res);
 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
                                                 const char *name,
-                                                unsigned int len);
+                                                unsigned int len,
+                                                unsigned int hash);
 struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
                                               const char *name,
                                               unsigned int len);
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 8f3a9e3106fd..a818fde24476 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -90,7 +90,6 @@ void __dlm_insert_lockres(struct dlm_ctxt *dlm,
         assert_spin_locked(&dlm->spinlock);
 
         q = &res->lockname;
-        q->hash = full_name_hash(q->name, q->len);
         bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]);
 
         /* get a reference for our hashtable */
@@ -100,10 +99,10 @@ void __dlm_insert_lockres(struct dlm_ctxt *dlm,
 }
 
 struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
-                                         const char *name,
-                                         unsigned int len)
+                                                const char *name,
+                                                unsigned int len,
+                                                unsigned int hash)
 {
-        unsigned int hash;
         struct hlist_node *iter;
         struct dlm_lock_resource *tmpres=NULL;
         struct hlist_head *bucket;
@@ -112,8 +111,6 @@ struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
 
         assert_spin_locked(&dlm->spinlock);
 
-        hash = full_name_hash(name, len);
-
         bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
 
         /* check for pre-existing lock */
@@ -135,9 +132,10 @@ struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
                                     unsigned int len)
 {
         struct dlm_lock_resource *res;
+        unsigned int hash = dlm_lockid_hash(name, len);
 
         spin_lock(&dlm->spinlock);
-        res = __dlm_lookup_lockres(dlm, name, len);
+        res = __dlm_lookup_lockres(dlm, name, len, hash);
         spin_unlock(&dlm->spinlock);
         return res;
 }
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 940be4c13b1f..953aa8421be4 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -603,7 +603,7 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
         memcpy(qname, name, namelen);
 
         res->lockname.len = namelen;
-        res->lockname.hash = full_name_hash(name, namelen);
+        res->lockname.hash = dlm_lockid_hash(name, namelen);
 
         init_waitqueue_head(&res->wq);
         spin_lock_init(&res->spinlock);
@@ -677,19 +677,20 @@ struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
         int blocked = 0;
         int ret, nodenum;
         struct dlm_node_iter iter;
-        unsigned int namelen;
+        unsigned int namelen, hash;
         int tries = 0;
         int bit, wait_on_recovery = 0;
 
         BUG_ON(!lockid);
 
         namelen = strlen(lockid);
+        hash = dlm_lockid_hash(lockid, namelen);
 
         mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
 
 lookup:
         spin_lock(&dlm->spinlock);
-        tmpres = __dlm_lookup_lockres(dlm, lockid, namelen);
+        tmpres = __dlm_lookup_lockres(dlm, lockid, namelen, hash);
         if (tmpres) {
                 spin_unlock(&dlm->spinlock);
                 mlog(0, "found in hash!\n");
@@ -1316,7 +1317,7 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
         struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
         struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
         char *name;
-        unsigned int namelen;
+        unsigned int namelen, hash;
         int found, ret;
         int set_maybe;
         int dispatch_assert = 0;
@@ -1331,6 +1332,7 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
         name = request->name;
         namelen = request->namelen;
+        hash = dlm_lockid_hash(name, namelen);
 
         if (namelen > DLM_LOCKID_NAME_MAX) {
                 response = DLM_IVBUFLEN;
@@ -1339,7 +1341,7 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
 way_up_top:
         spin_lock(&dlm->spinlock);
-        res = __dlm_lookup_lockres(dlm, name, namelen);
+        res = __dlm_lookup_lockres(dlm, name, namelen, hash);
         if (res) {
                 spin_unlock(&dlm->spinlock);
 
@@ -1612,7 +1614,7 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
         struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
         struct dlm_lock_resource *res = NULL;
         char *name;
-        unsigned int namelen;
+        unsigned int namelen, hash;
         u32 flags;
         int master_request = 0;
         int ret = 0;
@@ -1622,6 +1624,7 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
 
         name = assert->name;
         namelen = assert->namelen;
+        hash = dlm_lockid_hash(name, namelen);
         flags = be32_to_cpu(assert->flags);
 
         if (namelen > DLM_LOCKID_NAME_MAX) {
@@ -1670,7 +1673,7 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
 
         /* ok everything checks out with the MLE
          * now check to see if there is a lockres */
-        res = __dlm_lookup_lockres(dlm, name, namelen);
+        res = __dlm_lookup_lockres(dlm, name, namelen, hash);
         if (res) {
                 spin_lock(&res->spinlock);
                 if (res->state & DLM_LOCK_RES_RECOVERING)  {
@@ -2462,7 +2465,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
         struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
         struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
         const char *name;
-        unsigned int namelen;
+        unsigned int namelen, hash;
         int ret = 0;
 
         if (!dlm_grab(dlm))
@@ -2470,6 +2473,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
         name = migrate->name;
         namelen = migrate->namelen;
+        hash = dlm_lockid_hash(name, namelen);
 
         /* preallocate.. if this fails, abort */
         mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
@@ -2482,7 +2486,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
         /* check for pre-existing lock */
         spin_lock(&dlm->spinlock);
-        res = __dlm_lookup_lockres(dlm, name, namelen);
+        res = __dlm_lookup_lockres(dlm, name, namelen, hash);
         spin_lock(&dlm->master_lock);
 
         if (res) {
@@ -2601,6 +2605,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
         struct list_head *iter, *iter2;
         struct dlm_master_list_entry *mle;
         struct dlm_lock_resource *res;
+        unsigned int hash;
 
         mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
 top:
@@ -2684,8 +2689,9 @@ top:
                      mle->master, mle->new_master);
                 /* if there is a lockres associated with this
                  * mle, find it and set its owner to UNKNOWN */
+                hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
                 res = __dlm_lookup_lockres(dlm, mle->u.name.name,
-                                        mle->u.name.len);
+                                           mle->u.name.len, hash);
                 if (res) {
                         /* unfortunately if we hit this rare case, our
                          * lock ordering is messed.  we need to drop
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 9962190e7416..4f3d482a7299 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1404,6 +1404,7 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data)
         struct dlm_ctxt *dlm = data;
         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
         struct dlm_lock_resource *res = NULL;
+        unsigned int hash;
         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
         u32 flags = DLM_ASSERT_MASTER_REQUERY;
 
@@ -1413,8 +1414,10 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data)
                 return master;
         }
 
+        hash = dlm_lockid_hash(req->name, req->namelen);
+
         spin_lock(&dlm->spinlock);
-        res = __dlm_lookup_lockres(dlm, req->name, req->namelen);
+        res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
         if (res) {
                 spin_lock(&res->spinlock);
                 master = res->owner;