5 files changed, 335 insertions, 246 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index bb53714813a..0102be35980 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -52,16 +52,12 @@
 enum dlm_mle_type {
 	DLM_MLE_BLOCK,
 	DLM_MLE_MASTER,
-	DLM_MLE_MIGRATION
-};
-
-struct dlm_lock_name {
-	u8 len;
-	u8 name[DLM_LOCKID_NAME_MAX];
+	DLM_MLE_MIGRATION,
+	DLM_MLE_NUM_TYPES
 };
 
 struct dlm_master_list_entry {
-	struct list_head list;
+	struct hlist_node master_hash_node;
 	struct list_head hb_events;
 	struct dlm_ctxt *dlm;
 	spinlock_t spinlock;
@@ -78,10 +74,10 @@ struct dlm_master_list_entry {
 	enum dlm_mle_type type;
 	struct o2hb_callback_func mle_hb_up;
 	struct o2hb_callback_func mle_hb_down;
-	union {
-		struct dlm_lock_resource *res;
-		struct dlm_lock_name name;
-	} u;
+	struct dlm_lock_resource *mleres;
+	unsigned char mname[DLM_LOCKID_NAME_MAX];
+	unsigned int mnamelen;
+	unsigned int mnamehash;
 };
 
 enum dlm_ast_type {
@@ -151,13 +147,14 @@ struct dlm_ctxt
 	unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
 	struct dlm_recovery_ctxt reco;
 	spinlock_t master_lock;
-	struct list_head master_list;
+	struct hlist_head **master_hash;
 	struct list_head mle_hb_events;
 
 	/* these give a really vague idea of the system load */
-	atomic_t local_resources;
-	atomic_t remote_resources;
-	atomic_t unknown_resources;
+	atomic_t mle_tot_count[DLM_MLE_NUM_TYPES];
+	atomic_t mle_cur_count[DLM_MLE_NUM_TYPES];
+	atomic_t res_tot_count;
+	atomic_t res_cur_count;
 
 	struct dlm_debug_ctxt *dlm_debug_ctxt;
 	struct dentry *dlm_debugfs_subroot;
@@ -195,6 +192,13 @@ static inline struct hlist_head *dlm_lockres_hash(struct dlm_ctxt *dlm, unsigned
 	return dlm->lockres_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] + (i % DLM_BUCKETS_PER_PAGE);
 }
 
+static inline struct hlist_head *dlm_master_hash(struct dlm_ctxt *dlm,
+						 unsigned i)
+{
+	return dlm->master_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES] +
+			(i % DLM_BUCKETS_PER_PAGE);
+}
+
 /* these keventd work queue items are for less-frequently
  * called functions that cannot be directly called from the
  * net message handlers for some reason, usually because
@@ -848,9 +852,7 @@ struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
 					      unsigned int len);
 
 int dlm_is_host_down(int errno);
-void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
-			      struct dlm_lock_resource *res,
-			      u8 owner);
+
 struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
 						 const char *lockid,
 						 int namelen,
@@ -1008,6 +1010,9 @@ static inline void __dlm_wait_on_lockres(struct dlm_lock_resource *res)
 					  DLM_LOCK_RES_MIGRATING));
 }
 
+void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle);
+void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle);
+
 /* create/destroy slab caches */
 int dlm_init_master_caches(void);
 void dlm_destroy_master_caches(void);
@@ -1110,6 +1115,23 @@ static inline int dlm_node_iter_next(struct dlm_node_iter *iter)
 	return bit;
 }
 
+static inline void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
+					 struct dlm_lock_resource *res,
+					 u8 owner)
+{
+	assert_spin_locked(&res->spinlock);
+
+	res->owner = owner;
+}
 
+static inline void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
+					    struct dlm_lock_resource *res,
+					    u8 owner)
+{
+	assert_spin_locked(&res->spinlock);
+
+	if (owner != res->owner)
+		dlm_set_lockres_owner(dlm, res, owner);
+}
 
 #endif /* DLMCOMMON_H */
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index b32f60a5acf..df52f706f66 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -287,18 +287,8 @@ static int stringify_nodemap(unsigned long *nodemap, int maxnodes,
 static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
 {
 	int out = 0;
-	unsigned int namelen;
-	const char *name;
 	char *mle_type;
 
-	if (mle->type != DLM_MLE_MASTER) {
-		namelen = mle->u.name.len;
-		name = mle->u.name.name;
-	} else {
-		namelen = mle->u.res->lockname.len;
-		name = mle->u.res->lockname.name;
-	}
-
 	if (mle->type == DLM_MLE_BLOCK)
 		mle_type = "BLK";
 	else if (mle->type == DLM_MLE_MASTER)
@@ -306,7 +296,7 @@ static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
 	else
 		mle_type = "MIG";
 
-	out += stringify_lockname(name, namelen, buf + out, len - out);
+	out += stringify_lockname(mle->mname, mle->mnamelen, buf + out, len - out);
 	out += snprintf(buf + out, len - out,
 			"\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
 			mle_type, mle->master, mle->new_master,
@@ -501,23 +491,33 @@ static struct file_operations debug_purgelist_fops = {
 static int debug_mle_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
 {
 	struct dlm_master_list_entry *mle;
-	int out = 0;
-	unsigned long total = 0;
+	struct hlist_head *bucket;
+	struct hlist_node *list;
+	int i, out = 0;
+	unsigned long total = 0, longest = 0, bktcnt;
 
 	out += snprintf(db->buf + out, db->len - out,
 			"Dumping MLEs for Domain: %s\n", dlm->name);
 
 	spin_lock(&dlm->master_lock);
-	list_for_each_entry(mle, &dlm->master_list, list) {
-		++total;
-		if (db->len - out < 200)
-			continue;
-		out += dump_mle(mle, db->buf + out, db->len - out);
+	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);
+			++total;
+			++bktcnt;
+			if (db->len - out < 200)
+				continue;
+			out += dump_mle(mle, db->buf + out, db->len - out);
+		}
+		longest = max(longest, bktcnt);
+		bktcnt = 0;
 	}
 	spin_unlock(&dlm->master_lock);
 
 	out += snprintf(db->buf + out, db->len - out,
-			"Total on list: %ld\n", total);
+			"Total: %ld, Longest: %ld\n", total, longest);
 	return out;
 }
 
@@ -756,12 +756,8 @@ static int debug_state_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
 	int out = 0;
 	struct dlm_reco_node_data *node;
 	char *state;
-	int lres, rres, ures, tres;
-
-	lres = atomic_read(&dlm->local_resources);
-	rres = atomic_read(&dlm->remote_resources);
-	ures = atomic_read(&dlm->unknown_resources);
-	tres = lres + rres + ures;
+	int cur_mles = 0, tot_mles = 0;
+	int i;
 
 	spin_lock(&dlm->spinlock);
 
@@ -804,21 +800,48 @@ static int debug_state_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
 				 db->buf + out, db->len - out);
 	out += snprintf(db->buf + out, db->len - out, "\n");
 
-	/* Mastered Resources Total: xxx  Locally: xxx  Remotely: ... */
+	/* Lock Resources: xxx (xxx) */
+	out += snprintf(db->buf + out, db->len - out,
+			"Lock Resources: %d (%d)\n",
+			atomic_read(&dlm->res_cur_count),
+			atomic_read(&dlm->res_tot_count));
+
+	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
+		tot_mles += atomic_read(&dlm->mle_tot_count[i]);
+
+	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
+		cur_mles += atomic_read(&dlm->mle_cur_count[i]);
+
+	/* MLEs: xxx (xxx) */
+	out += snprintf(db->buf + out, db->len - out,
+			"MLEs: %d (%d)\n", cur_mles, tot_mles);
+
+	/*  Blocking: xxx (xxx) */
+	out += snprintf(db->buf + out, db->len - out,
+			"  Blocking: %d (%d)\n",
+			atomic_read(&dlm->mle_cur_count[DLM_MLE_BLOCK]),
+			atomic_read(&dlm->mle_tot_count[DLM_MLE_BLOCK]));
+
+	/*  Mastery: xxx (xxx) */
+	out += snprintf(db->buf + out, db->len - out,
+			"  Mastery: %d (%d)\n",
+			atomic_read(&dlm->mle_cur_count[DLM_MLE_MASTER]),
+			atomic_read(&dlm->mle_tot_count[DLM_MLE_MASTER]));
+
+	/*  Migration: xxx (xxx) */
 	out += snprintf(db->buf + out, db->len - out,
-			"Mastered Resources Total: %d  Locally: %d  "
-			"Remotely: %d  Unknown: %d\n",
-			tres, lres, rres, ures);
+			"  Migration: %d (%d)\n",
+			atomic_read(&dlm->mle_cur_count[DLM_MLE_MIGRATION]),
+			atomic_read(&dlm->mle_tot_count[DLM_MLE_MIGRATION]));
 
 	/* Lists: Dirty=Empty  Purge=InUse  PendingASTs=Empty  ... */
 	out += snprintf(db->buf + out, db->len - out,
 			"Lists: Dirty=%s  Purge=%s  PendingASTs=%s  "
-			"PendingBASTs=%s  Master=%s\n",
+			"PendingBASTs=%s\n",
 			(list_empty(&dlm->dirty_list) ? "Empty" : "InUse"),
 			(list_empty(&dlm->purge_list) ? "Empty" : "InUse"),
 			(list_empty(&dlm->pending_asts) ? "Empty" : "InUse"),
-			(list_empty(&dlm->pending_basts) ? "Empty" : "InUse"),
-			(list_empty(&dlm->master_list) ? "Empty" : "InUse"));
+			(list_empty(&dlm->pending_basts) ? "Empty" : "InUse"));
 
 	/* Purge Count: xxx  Refs: xxx */
 	out += snprintf(db->buf + out, db->len - out,
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index d8d578f4561..4d9e6b288dd 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -304,6 +304,9 @@ static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 	if (dlm->lockres_hash)
 		dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 
+	if (dlm->master_hash)
+		dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
+
 	if (dlm->name)
 		kfree(dlm->name);
 
@@ -1534,12 +1537,27 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 	for (i = 0; i < DLM_HASH_BUCKETS; i++)
 		INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
 
+	dlm->master_hash = (struct hlist_head **)
+				dlm_alloc_pagevec(DLM_HASH_PAGES);
+	if (!dlm->master_hash) {
+		mlog_errno(-ENOMEM);
+		dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
+		kfree(dlm->name);
+		kfree(dlm);
+		dlm = NULL;
+		goto leave;
+	}
+
+	for (i = 0; i < DLM_HASH_BUCKETS; i++)
+		INIT_HLIST_HEAD(dlm_master_hash(dlm, i));
+
 	strcpy(dlm->name, domain);
 	dlm->key = key;
 	dlm->node_num = o2nm_this_node();
 
 	ret = dlm_create_debugfs_subroot(dlm);
 	if (ret < 0) {
+		dlm_free_pagevec((void **)dlm->master_hash, DLM_HASH_PAGES);
 		dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 		kfree(dlm->name);
 		kfree(dlm);
@@ -1579,7 +1597,6 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 	init_waitqueue_head(&dlm->reco.event);
 	init_waitqueue_head(&dlm->ast_wq);
 	init_waitqueue_head(&dlm->migration_wq);
-	INIT_LIST_HEAD(&dlm->master_list);
 	INIT_LIST_HEAD(&dlm->mle_hb_events);
 
 	dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
@@ -1587,9 +1604,13 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 
 	dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
 	dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
-	atomic_set(&dlm->local_resources, 0);
-	atomic_set(&dlm->remote_resources, 0);
-	atomic_set(&dlm->unknown_resources, 0);
+
+	atomic_set(&dlm->res_tot_count, 0);
+	atomic_set(&dlm->res_cur_count, 0);
+	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i) {
+		atomic_set(&dlm->mle_tot_count[i], 0);
+		atomic_set(&dlm->mle_cur_count[i], 0);
+	}
 
 	spin_lock_init(&dlm->work_lock);
 	INIT_LIST_HEAD(&dlm->work_list);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 0a281394785..f8b653fcd4d 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -73,22 +73,13 @@ static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
 				const char *name,
 				unsigned int namelen)
 {
-	struct dlm_lock_resource *res;
-
 	if (dlm != mle->dlm)
 		return 0;
 
-	if (mle->type == DLM_MLE_BLOCK ||
-	    mle->type == DLM_MLE_MIGRATION) {
-		if (namelen != mle->u.name.len ||
-    	    	    memcmp(name, mle->u.name.name, namelen)!=0)
-			return 0;
-	} else {
-		res = mle->u.res;
-		if (namelen != res->lockname.len ||
-		    memcmp(res->lockname.name, name, namelen) != 0)
-			return 0;
-	}
+	if (namelen != mle->mnamelen ||
+	    memcmp(name, mle->mname, namelen) != 0)
+		return 0;
+
 	return 1;
 }
 
@@ -283,7 +274,7 @@ 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);
@@ -295,19 +286,27 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle,
 	mle->new_master = O2NM_MAX_NODES;
 	mle->inuse = 0;
 
+	BUG_ON(mle->type != DLM_MLE_BLOCK &&
+	       mle->type != DLM_MLE_MASTER &&
+	       mle->type != DLM_MLE_MIGRATION);
+
 	if (mle->type == DLM_MLE_MASTER) {
 		BUG_ON(!res);
-		mle->u.res = res;
-	} else if (mle->type == DLM_MLE_BLOCK) {
-		BUG_ON(!name);
-		memcpy(mle->u.name.name, name, namelen);
-		mle->u.name.len = namelen;
-	} else /* DLM_MLE_MIGRATION */ {
+		mle->mleres = res;
+		memcpy(mle->mname, res->lockname.name, res->lockname.len);
+		mle->mnamelen = res->lockname.len;
+		mle->mnamehash = res->lockname.hash;
+	} else {
 		BUG_ON(!name);
-		memcpy(mle->u.name.name, name, namelen);
-		mle->u.name.len = namelen;
+		mle->mleres = NULL;
+		memcpy(mle->mname, name, namelen);
+		mle->mnamelen = namelen;
+		mle->mnamehash = dlm_lockid_hash(name, namelen);
 	}
 
+	atomic_inc(&dlm->mle_tot_count[mle->type]);
+	atomic_inc(&dlm->mle_cur_count[mle->type]);
+
 	/* copy off the node_map and register hb callbacks on our copy */
 	memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map));
 	memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map));
@@ -318,6 +317,24 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle,
 	__dlm_mle_attach_hb_events(dlm, mle);
 }
 
+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 (!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;
+
+	assert_spin_locked(&dlm->master_lock);
+
+	bucket = dlm_master_hash(dlm, mle->mnamehash);
+	hlist_add_head(&mle->master_hash_node, bucket);
+}
 
 /* returns 1 if found, 0 if not */
 static int dlm_find_mle(struct dlm_ctxt *dlm,
@@ -325,10 +342,17 @@ 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);
@@ -408,24 +432,20 @@ static void dlm_mle_release(struct kref *kref)
 	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.name.len, mle->u.name.name, mle->type);
-	} else {
-		mlog(0, "calling mle_release for %.*s, type %d\n",
-		     mle->u.res->lockname.len,
-		     mle->u.res->lockname.name, mle->type);
-	}
 	assert_spin_locked(&dlm->spinlock);
 	assert_spin_locked(&dlm->master_lock);
 
+	mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname,
+	     mle->type);
+
 	/* remove from list if not already */
-	if (!list_empty(&mle->list))
-		list_del_init(&mle->list);
+	__dlm_unlink_mle(dlm, mle);
 
 	/* detach the mle from the domain node up/down events */
 	__dlm_mle_detach_hb_events(dlm, mle);
 
+	atomic_dec(&dlm->mle_cur_count[mle->type]);
+
 	/* NOTE: kfree under spinlock here.
 	 * if this is bad, we can move this to a freelist. */
 	kmem_cache_free(dlm_mle_cache, mle);
@@ -465,43 +485,6 @@ void dlm_destroy_master_caches(void)
 		kmem_cache_destroy(dlm_lockres_cache);
 }
 
-static void dlm_set_lockres_owner(struct dlm_ctxt *dlm,
-				  struct dlm_lock_resource *res,
-				  u8 owner)
-{
-	assert_spin_locked(&res->spinlock);
-
-	mlog_entry("%.*s, %u\n", res->lockname.len, res->lockname.name, owner);
-
-	if (owner == dlm->node_num)
-		atomic_inc(&dlm->local_resources);
-	else if (owner == DLM_LOCK_RES_OWNER_UNKNOWN)
-		atomic_inc(&dlm->unknown_resources);
-	else
-		atomic_inc(&dlm->remote_resources);
-
-	res->owner = owner;
-}
-
-void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
-			      struct dlm_lock_resource *res, u8 owner)
-{
-	assert_spin_locked(&res->spinlock);
-
-	if (owner == res->owner)
-		return;
-
-	if (res->owner == dlm->node_num)
-		atomic_dec(&dlm->local_resources);
-	else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN)
-		atomic_dec(&dlm->unknown_resources);
-	else
-		atomic_dec(&dlm->remote_resources);
-
-	dlm_set_lockres_owner(dlm, res, owner);
-}
-
-
 static void dlm_lockres_release(struct kref *kref)
 {
 	struct dlm_lock_resource *res;
@@ -527,6 +510,8 @@ static void dlm_lockres_release(struct kref *kref)
 	}
 	spin_unlock(&dlm->track_lock);
 
+	atomic_dec(&dlm->res_cur_count);
+
 	dlm_put(dlm);
 
 	if (!hlist_unhashed(&res->hash_node) ||
@@ -607,6 +592,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
 
 	kref_init(&res->refs);
 
+	atomic_inc(&dlm->res_tot_count);
+	atomic_inc(&dlm->res_cur_count);
+
 	/* just for consistency */
 	spin_lock(&res->spinlock);
 	dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
@@ -843,7 +831,7 @@ lookup:
 		alloc_mle = NULL;
 		dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
 		set_bit(dlm->node_num, mle->maybe_map);
-		list_add(&mle->list, &dlm->master_list);
+		__dlm_insert_mle(dlm, mle);
 
 		/* still holding the dlm spinlock, check the recovery map
 		 * to see if there are any nodes that still need to be 
@@ -1270,7 +1258,7 @@ static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
 						     res->lockname.len,
 						     res->lockname.name);
 						mle->type = DLM_MLE_MASTER;
-						mle->u.res = res;
+						mle->mleres = res;
 					}
 				}
 			}
@@ -1315,14 +1303,8 @@ static int dlm_do_master_request(struct dlm_lock_resource *res,
 
 	BUG_ON(mle->type == DLM_MLE_MIGRATION);
 
-	if (mle->type != DLM_MLE_MASTER) {
-		request.namelen = mle->u.name.len;
-		memcpy(request.name, mle->u.name.name, request.namelen);
-	} else {
-		request.namelen = mle->u.res->lockname.len;
-		memcpy(request.name, mle->u.res->lockname.name,
-			request.namelen);
-	}
+	request.namelen = (u8)mle->mnamelen;
+	memcpy(request.name, mle->mname, request.namelen);
 
 again:
 	ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request,
@@ -1575,7 +1557,7 @@ way_up_top:
 		// "add the block.\n");
 		dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
 		set_bit(request->node_idx, mle->maybe_map);
-		list_add(&mle->list, &dlm->master_list);
+		__dlm_insert_mle(dlm, mle);
 		response = DLM_MASTER_RESP_NO;
 	} else {
 		// mlog(0, "mle was found\n");
@@ -1967,7 +1949,7 @@ ok:
 			     assert->node_idx, rr, extra_ref, mle->inuse);
 			dlm_print_one_mle(mle);
 		}
-		list_del_init(&mle->list);
+		__dlm_unlink_mle(dlm, mle);
 		__dlm_mle_detach_hb_events(dlm, mle);
 		__dlm_put_mle(mle);
 		if (extra_ref) {
@@ -3159,10 +3141,8 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
 			tmp->master = master;
 			atomic_set(&tmp->woken, 1);
 			wake_up(&tmp->wq);
-			/* remove it from the list so that only one
-			 * mle will be found */
-			list_del_init(&tmp->list);
-			/* this was obviously WRONG.  mle is uninited here.  should be tmp. */
+			/* remove it so that only one mle will be found */
+			__dlm_unlink_mle(dlm, tmp);
 			__dlm_mle_detach_hb_events(dlm, tmp);
 			ret = DLM_MIGRATE_RESPONSE_MASTERY_REF;
 			mlog(0, "%s:%.*s: master=%u, newmaster=%u, "
@@ -3181,137 +3161,164 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
 	mle->master = master;
 	/* do this for consistency with other mle types */
 	set_bit(new_master, mle->maybe_map);
-	list_add(&mle->list, &dlm->master_list);
+	__dlm_insert_mle(dlm, mle);
 
 	return ret;
 }
 
-
-void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
+/*
+ * Sets the owner of the lockres, associated to the mle, to UNKNOWN
+ */
+static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm,
+					struct dlm_master_list_entry *mle)
 {
-	struct dlm_master_list_entry *mle, *next;
 	struct dlm_lock_resource *res;
-	unsigned int hash;
 
-	mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
-top:
-	assert_spin_locked(&dlm->spinlock);
+	/* Find the lockres associated to the mle and set its owner to UNK */
+	res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen,
+				   mle->mnamehash);
+	if (res) {
+		spin_unlock(&dlm->master_lock);
 
-	/* clean the master list */
-	spin_lock(&dlm->master_lock);
-	list_for_each_entry_safe(mle, next, &dlm->master_list, list) {
-		BUG_ON(mle->type != DLM_MLE_BLOCK &&
-		       mle->type != DLM_MLE_MASTER &&
-		       mle->type != DLM_MLE_MIGRATION);
-
-		/* MASTER mles are initiated locally.  the waiting
-		 * process will notice the node map change
-		 * shortly.  let that happen as normal. */
-		if (mle->type == DLM_MLE_MASTER)
-			continue;
+		/* move lockres onto recovery list */
+		spin_lock(&res->spinlock);
+		dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN);
+		dlm_move_lockres_to_recovery_list(dlm, res);
+		spin_unlock(&res->spinlock);
+		dlm_lockres_put(res);
 
+		/* about to get rid of mle, detach from heartbeat */
+		__dlm_mle_detach_hb_events(dlm, mle);
 
-		/* BLOCK mles are initiated by other nodes.
-		 * need to clean up if the dead node would have
-		 * been the master. */
-		if (mle->type == DLM_MLE_BLOCK) {
-			int bit;
+		/* dump the mle */
+		spin_lock(&dlm->master_lock);
+		__dlm_put_mle(mle);
+		spin_unlock(&dlm->master_lock);
+	}
 
-			spin_lock(&mle->spinlock);
-			bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
-			if (bit != dead_node) {
-				mlog(0, "mle found, but dead node %u would "
-				     "not have been master\n", dead_node);
-				spin_unlock(&mle->spinlock);
-			} else {
-				/* must drop the refcount by one since the
-				 * assert_master will never arrive.  this
-				 * may result in the mle being unlinked and
-				 * freed, but there may still be a process
-				 * waiting in the dlmlock path which is fine. */
-				mlog(0, "node %u was expected master\n",
-				     dead_node);
-				atomic_set(&mle->woken, 1);
-				spin_unlock(&mle->spinlock);
-				wake_up(&mle->wq);
-				/* do not need events any longer, so detach 
-				 * from heartbeat */
-				__dlm_mle_detach_hb_events(dlm, mle);
-				__dlm_put_mle(mle);
-			}
-			continue;
-		}
+	return res;
+}
 
-		/* everything else is a MIGRATION mle */
-
-		/* the rule for MIGRATION mles is that the master
-		 * becomes UNKNOWN if *either* the original or
-		 * the new master dies.  all UNKNOWN lockreses
-		 * are sent to whichever node becomes the recovery
-		 * master.  the new master is responsible for
-		 * determining if there is still a master for
-		 * this lockres, or if he needs to take over
-		 * mastery.  either way, this node should expect
-		 * another message to resolve this. */
-		if (mle->master != dead_node &&
-		    mle->new_master != dead_node)
-			continue;
+static void dlm_clean_migration_mle(struct dlm_ctxt *dlm,
+				    struct dlm_master_list_entry *mle)
+{
+	__dlm_mle_detach_hb_events(dlm, mle);
 
-		/* if we have reached this point, this mle needs to
-		 * be removed from the list and freed. */
+	spin_lock(&mle->spinlock);
+	__dlm_unlink_mle(dlm, mle);
+	atomic_set(&mle->woken, 1);
+	spin_unlock(&mle->spinlock);
 
-		/* remove from the list early.  NOTE: unlinking
-		 * list_head while in list_for_each_safe */
-		__dlm_mle_detach_hb_events(dlm, mle);
-		spin_lock(&mle->spinlock);
-		list_del_init(&mle->list);
+	wake_up(&mle->wq);
+}
+
+static void dlm_clean_block_mle(struct dlm_ctxt *dlm,
+				struct dlm_master_list_entry *mle, u8 dead_node)
+{
+	int bit;
+
+	BUG_ON(mle->type != DLM_MLE_BLOCK);
+
+	spin_lock(&mle->spinlock);
+	bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0);
+	if (bit != dead_node) {
+		mlog(0, "mle found, but dead node %u would not have been "
+		     "master\n", dead_node);
+		spin_unlock(&mle->spinlock);
+	} else {
+		/* Must drop the refcount by one since the assert_master will
+		 * never arrive. This may result in the mle being unlinked and
+		 * freed, but there may still be a process waiting in the
+		 * dlmlock path which is fine. */
+		mlog(0, "node %u was expected master\n", dead_node);
 		atomic_set(&mle->woken, 1);
 		spin_unlock(&mle->spinlock);
 		wake_up(&mle->wq);
 
-		mlog(0, "%s: node %u died during migration from "
-		     "%u to %u!\n", dlm->name, dead_node,
-		     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, hash);
-		if (res) {
-			/* unfortunately if we hit this rare case, our
-		 	 * lock ordering is messed.  we need to drop
-		 	 * the master lock so that we can take the
-		  	 * lockres lock, meaning that we will have to
-			 * restart from the head of list. */
-			spin_unlock(&dlm->master_lock);
+		/* Do not need events any longer, so detach from heartbeat */
+		__dlm_mle_detach_hb_events(dlm, mle);
+		__dlm_put_mle(mle);
+	}
+}
 
-			/* move lockres onto recovery list */
-			spin_lock(&res->spinlock);
-			dlm_set_lockres_owner(dlm, res,
-				      	DLM_LOCK_RES_OWNER_UNKNOWN);
-			dlm_move_lockres_to_recovery_list(dlm, res);
-			spin_unlock(&res->spinlock);
-			dlm_lockres_put(res);
+void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
+{
+	struct dlm_master_list_entry *mle;
+	struct dlm_lock_resource *res;
+	struct hlist_head *bucket;
+	struct hlist_node *list;
+	unsigned int i;
 
-			/* about to get rid of mle, detach from heartbeat */
-			__dlm_mle_detach_hb_events(dlm, mle);
+	mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
+top:
+	assert_spin_locked(&dlm->spinlock);
 
-			/* dump the mle */
-			spin_lock(&dlm->master_lock);
-			__dlm_put_mle(mle);
-			spin_unlock(&dlm->master_lock);
+	/* clean the master list */
+	spin_lock(&dlm->master_lock);
+	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);
+
+			/* MASTER mles are initiated locally. The waiting
+			 * process will notice the node map change shortly.
+			 * Let that happen as normal. */
+			if (mle->type == DLM_MLE_MASTER)
+				continue;
+
+			/* BLOCK mles are initiated by other nodes. Need to
+			 * clean up if the dead node would have been the
+			 * master. */
+			if (mle->type == DLM_MLE_BLOCK) {
+				dlm_clean_block_mle(dlm, mle, dead_node);
+				continue;
+			}
 
-			/* restart */
-			goto top;
-		}
+			/* Everything else is a MIGRATION mle */
+
+			/* The rule for MIGRATION mles is that the master
+			 * becomes UNKNOWN if *either* the original or the new
+			 * master dies. All UNKNOWN lockres' are sent to
+			 * whichever node becomes the recovery master. The new
+			 * master is responsible for determining if there is
+			 * still a master for this lockres, or if he needs to
+			 * take over mastery. Either way, this node should
+			 * expect another message to resolve this. */
+
+			if (mle->master != dead_node &&
+			    mle->new_master != dead_node)
+				continue;
+
+			/* If we have reached this point, this mle needs to be
+			 * removed from the list and freed. */
+			dlm_clean_migration_mle(dlm, mle);
+
+			mlog(0, "%s: node %u died during migration from "
+			     "%u to %u!\n", dlm->name, dead_node, mle->master,
+			     mle->new_master);
+
+			/* If we find a lockres associated with the mle, we've
+			 * hit this rare case that messes up our lock ordering.
+			 * If so, we need to drop the master lock so that we can
+			 * take the lockres lock, meaning that we will have to
+			 * restart from the head of list. */
+			res = dlm_reset_mleres_owner(dlm, mle);
+			if (res)
+				/* restart */
+				goto top;
 
-		/* this may be the last reference */
-		__dlm_put_mle(mle);
+			/* This may be the last reference */
+			__dlm_put_mle(mle);
+		}
 	}
 	spin_unlock(&dlm->master_lock);
 }
 
-
 int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 			 u8 old_master)
 {
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 4060bb328bc..d490b66ad9d 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -162,12 +162,28 @@ static int dlm_purge_lockres(struct dlm_ctxt *dlm,
 
 	spin_lock(&res->spinlock);
 	if (!__dlm_lockres_unused(res)) {
-		spin_unlock(&res->spinlock);
 		mlog(0, "%s:%.*s: tried to purge but not unused\n",
 		     dlm->name, res->lockname.len, res->lockname.name);
-		return -ENOTEMPTY;
+		__dlm_print_one_lock_resource(res);
+		spin_unlock(&res->spinlock);
+		BUG();
 	}
+
+	if (res->state & DLM_LOCK_RES_MIGRATING) {
+		mlog(0, "%s:%.*s: Delay dropref as this lockres is "
+		     "being remastered\n", dlm->name, res->lockname.len,
+		     res->lockname.name);
+		/* Re-add the lockres to the end of the purge list */
+		if (!list_empty(&res->purge)) {
+			list_del_init(&res->purge);
+			list_add_tail(&res->purge, &dlm->purge_list);
+		}
+		spin_unlock(&res->spinlock);
+		return 0;
+	}
+
 	master = (res->owner == dlm->node_num);
+
 	if (!master)
 		res->state |= DLM_LOCK_RES_DROPPING_REF;
 	spin_unlock(&res->spinlock);