2 files changed, 94 insertions, 11 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 3f554711efe..2f4f5d4edb0 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -180,6 +180,11 @@ struct dlm_assert_master_priv
 	unsigned ignore_higher:1;
 };
 
+struct dlm_deref_lockres_priv
+{
+	struct dlm_lock_resource *deref_res;
+	u8 deref_node;
+};
 
 struct dlm_work_item
 {
@@ -191,6 +196,7 @@ struct dlm_work_item
 		struct dlm_request_all_locks_priv ral;
 		struct dlm_mig_lockres_priv ml;
 		struct dlm_assert_master_priv am;
+		struct dlm_deref_lockres_priv dl;
 	} u;
 };
 
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 84f36db8ada..77e4e6169a0 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -102,6 +102,7 @@ static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
 				struct dlm_lock_resource *res,
 				void *nodemap, u32 flags);
+static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
 
 static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
 				struct dlm_master_list_entry *mle,
@@ -1717,6 +1718,11 @@ int dlm_do_assert_master(struct dlm_ctxt *dlm,
 	unsigned int namelen = res->lockname.len;
 
 	BUG_ON(namelen > O2NM_MAX_NAME_LEN);
+
+	spin_lock(&res->spinlock);
+	res->state |= DLM_LOCK_RES_SETREF_INPROG;
+	spin_unlock(&res->spinlock);
+
 again:
 	reassert = 0;
 
@@ -1789,6 +1795,11 @@ again:
 	if (reassert)
 		goto again;
 
+	spin_lock(&res->spinlock);
+	res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
+	spin_unlock(&res->spinlock);
+	wake_up(&res->wq);
+
 	return ret;
 }
 
@@ -2296,6 +2307,9 @@ int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
 	int ret = -EINVAL;
 	u8 node;
 	unsigned int hash;
+	struct dlm_work_item *item;
+	int cleared = 0;
+	int dispatch = 0;
 
 	if (!dlm_grab(dlm))
 		return 0;
@@ -2326,27 +2340,90 @@ int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
 	spin_unlock(&dlm->spinlock);
 
 	spin_lock(&res->spinlock);
-	BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
-	if (test_bit(node, res->refmap)) {
-		ret = 0;
-		dlm_lockres_clear_refmap_bit(node, res);
-	} else {
-		mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
-		     "but it is already dropped!\n", dlm->name, namelen,
-		     name, node);
-		__dlm_print_one_lock_resource(res);
+	if (res->state & DLM_LOCK_RES_SETREF_INPROG)
+		dispatch = 1;
+	else {
+		BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
+		if (test_bit(node, res->refmap)) {
+			dlm_lockres_clear_refmap_bit(node, res);
+			cleared = 1;
+		}
 	}
 	spin_unlock(&res->spinlock);
 
-	if (!ret)
-		dlm_lockres_calc_usage(dlm, res);
+	if (!dispatch) {
+		if (cleared)
+			dlm_lockres_calc_usage(dlm, res);
+		else {
+			mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
+		     	"but it is already dropped!\n", dlm->name,
+		     	res->lockname.len, res->lockname.name, node);
+			__dlm_print_one_lock_resource(res);
+		}
+		ret = 0;
+		goto done;
+	}
+
+	item = kzalloc(sizeof(*item), GFP_NOFS);
+	if (!item) {
+		ret = -ENOMEM;
+		mlog_errno(ret);
+		goto done;
+	}
+
+	dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
+	item->u.dl.deref_res = res;
+	item->u.dl.deref_node = node;
+
+	spin_lock(&dlm->work_lock);
+	list_add_tail(&item->list, &dlm->work_list);
+	spin_unlock(&dlm->work_lock);
+
+	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
+	return 0;
+
 done:
 	if (res)
 		dlm_lockres_put(res);
 	dlm_put(dlm);
+
 	return ret;
 }
 
+static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
+{
+	struct dlm_ctxt *dlm;
+	struct dlm_lock_resource *res;
+	u8 node;
+	u8 cleared = 0;
+
+	dlm = item->dlm;
+	res = item->u.dl.deref_res;
+	node = item->u.dl.deref_node;
+
+	spin_lock(&res->spinlock);
+	BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
+	if (test_bit(node, res->refmap)) {
+		__dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
+		dlm_lockres_clear_refmap_bit(node, res);
+		cleared = 1;
+	}
+	spin_unlock(&res->spinlock);
+
+	if (cleared) {
+		mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
+		     dlm->name, res->lockname.len, res->lockname.name, node);
+		dlm_lockres_calc_usage(dlm, res);
+	} else {
+		mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
+		     "but it is already dropped!\n", dlm->name,
+		     res->lockname.len, res->lockname.name, node);
+		__dlm_print_one_lock_resource(res);
+	}
+
+	dlm_lockres_put(res);
+}
+
 
 /*
  * DLM_MIGRATE_LOCKRES