diff --git a/drivers/staging/lustre/lustre/include/lustre_dlm.h b/drivers/staging/lustre/lustre/include/lustre_dlm.h
index b7e61d082e55..1e86fb53388a 100644
--- a/drivers/staging/lustre/lustre/include/lustre_dlm.h
+++ b/drivers/staging/lustre/lustre/include/lustre_dlm.h
@@ -812,13 +812,6 @@ struct ldlm_lock {
 	/** referenced export object */
 	struct obd_export	*l_exp_refs_target;
 #endif
-	/**
-	 * export blocking dlm lock list, protected by
-	 * l_export->exp_bl_list_lock.
-	 * Lock order of waiting_lists_spinlock, exp_bl_list_lock and res lock
-	 * is: res lock -> exp_bl_list_lock -> wanting_lists_spinlock.
-	 */
-	struct list_head		l_exp_list;
 };
 
 /**
@@ -1192,6 +1185,10 @@ ldlm_namespace_new(struct obd_device *obd, char *name,
 		   enum ldlm_side client, enum ldlm_appetite apt,
 		   enum ldlm_ns_type ns_type);
 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, __u64 flags);
+void ldlm_namespace_free_prior(struct ldlm_namespace *ns,
+			       struct obd_import *imp,
+			       int force);
+void ldlm_namespace_free_post(struct ldlm_namespace *ns);
 void ldlm_namespace_get(struct ldlm_namespace *ns);
 void ldlm_namespace_put(struct ldlm_namespace *ns);
 int ldlm_debugfs_setup(void);
diff --git a/drivers/staging/lustre/lustre/include/obd_support.h b/drivers/staging/lustre/lustre/include/obd_support.h
index dace6591a0a4..33304041bb63 100644
--- a/drivers/staging/lustre/lustre/include/obd_support.h
+++ b/drivers/staging/lustre/lustre/include/obd_support.h
@@ -318,6 +318,7 @@ extern char obd_jobid_var[];
 #define OBD_FAIL_LDLM_AGL_NOLOCK	 0x31b
 #define OBD_FAIL_LDLM_OST_LVB		 0x31c
 #define OBD_FAIL_LDLM_ENQUEUE_HANG	 0x31d
+#define OBD_FAIL_LDLM_PAUSE_CANCEL2	 0x31f
 #define OBD_FAIL_LDLM_CP_CB_WAIT2	 0x320
 #define OBD_FAIL_LDLM_CP_CB_WAIT3	 0x321
 #define OBD_FAIL_LDLM_CP_CB_WAIT4	 0x322
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
index 5c02501d0560..5d24b4825796 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
@@ -108,9 +108,7 @@ extern unsigned int ldlm_cancel_unused_locks_before_replay;
 
 /* ldlm_resource.c */
 int ldlm_resource_putref_locked(struct ldlm_resource *res);
-void ldlm_namespace_free_prior(struct ldlm_namespace *ns,
-			       struct obd_import *imp, int force);
-void ldlm_namespace_free_post(struct ldlm_namespace *ns);
+
 /* ldlm_lock.c */
 
 struct ldlm_cb_set_arg {
@@ -156,6 +154,7 @@ int ldlm_bl_to_thread_list(struct ldlm_namespace *ns,
 			   struct ldlm_lock_desc *ld,
 			   struct list_head *cancels, int count,
 			   enum ldlm_cancel_flags cancel_flags);
+int ldlm_bl_thread_wakeup(void);
 
 void ldlm_handle_bl_callback(struct ldlm_namespace *ns,
 			     struct ldlm_lock_desc *ld, struct ldlm_lock *lock);
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c b/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c
index 16c2a8b001bc..ddb46428093f 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c
@@ -435,7 +435,6 @@ static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
 	lock->l_exp_refs_nr = 0;
 	lock->l_exp_refs_target = NULL;
 #endif
-	INIT_LIST_HEAD(&lock->l_exp_list);
 
 	return lock;
 }
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c b/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
index 12647af5a336..4c21b9bf7f9d 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c
@@ -454,6 +454,12 @@ int ldlm_bl_to_thread_list(struct ldlm_namespace *ns, struct ldlm_lock_desc *ld,
 	return ldlm_bl_to_thread(ns, ld, NULL, cancels, count, cancel_flags);
 }
 
+int ldlm_bl_thread_wakeup(void)
+{
+	wake_up(&ldlm_state->ldlm_bl_pool->blp_waitq);
+	return 0;
+}
+
 /* Setinfo coming from Server (eg MDT) to Client (eg MDC)! */
 static int ldlm_handle_setinfo(struct ptlrpc_request *req)
 {
@@ -675,8 +681,11 @@ static int ldlm_callback_handler(struct ptlrpc_request *req)
 	return 0;
 }
 
-static struct ldlm_bl_work_item *ldlm_bl_get_work(struct ldlm_bl_pool *blp)
+static int ldlm_bl_get_work(struct ldlm_bl_pool *blp,
+			    struct ldlm_bl_work_item **p_blwi,
+			    struct obd_export **p_exp)
 {
+	int num_th = atomic_read(&blp->blp_num_threads);
 	struct ldlm_bl_work_item *blwi = NULL;
 	static unsigned int num_bl;
 
@@ -693,13 +702,14 @@ static struct ldlm_bl_work_item *ldlm_bl_get_work(struct ldlm_bl_pool *blp)
 					  blwi_entry);
 
 	if (blwi) {
-		if (++num_bl >= atomic_read(&blp->blp_num_threads))
+		if (++num_bl >= num_th)
 			num_bl = 0;
 		list_del(&blwi->blwi_entry);
 	}
 	spin_unlock(&blp->blp_lock);
+	*p_blwi = blwi;
 
-	return blwi;
+	return (*p_blwi || *p_exp) ? 1 : 0;
 }
 
 /* This only contains temporary data until the thread starts */
@@ -732,6 +742,65 @@ static int ldlm_bl_thread_start(struct ldlm_bl_pool *blp)
 	return 0;
 }
 
+/* Not fatal if racy and have a few too many threads */
+static int ldlm_bl_thread_need_create(struct ldlm_bl_pool *blp,
+				      struct ldlm_bl_work_item *blwi)
+{
+	int busy = atomic_read(&blp->blp_busy_threads);
+
+	if (busy >= blp->blp_max_threads)
+		return 0;
+
+	if (busy < atomic_read(&blp->blp_num_threads))
+		return 0;
+
+	if (blwi && (!blwi->blwi_ns || blwi->blwi_mem_pressure))
+		return 0;
+
+	return 1;
+}
+
+static int ldlm_bl_thread_blwi(struct ldlm_bl_pool *blp,
+			       struct ldlm_bl_work_item *blwi)
+{
+	if (!blwi->blwi_ns)
+		/* added by ldlm_cleanup() */
+		return LDLM_ITER_STOP;
+
+	if (blwi->blwi_mem_pressure)
+		memory_pressure_set();
+
+	OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_PAUSE_CANCEL2, 4);
+
+	if (blwi->blwi_count) {
+		int count;
+
+		/*
+		 * The special case when we cancel locks in lru
+		 * asynchronously, we pass the list of locks here.
+		 * Thus locks are marked LDLM_FL_CANCELING, but NOT
+		 * canceled locally yet.
+		 */
+		count = ldlm_cli_cancel_list_local(&blwi->blwi_head,
+						   blwi->blwi_count,
+						   LCF_BL_AST);
+		ldlm_cli_cancel_list(&blwi->blwi_head, count, NULL,
+				     blwi->blwi_flags);
+	} else {
+		ldlm_handle_bl_callback(blwi->blwi_ns, &blwi->blwi_ld,
+					blwi->blwi_lock);
+	}
+	if (blwi->blwi_mem_pressure)
+		memory_pressure_clr();
+
+	if (blwi->blwi_flags & LCF_ASYNC)
+		kfree(blwi);
+	else
+		complete(&blwi->blwi_comp);
+
+	return 0;
+}
+
 /**
  * Main blocking requests processing thread.
  *
@@ -742,73 +811,41 @@ static int ldlm_bl_thread_start(struct ldlm_bl_pool *blp)
 static int ldlm_bl_thread_main(void *arg)
 {
 	struct ldlm_bl_pool *blp;
+	struct ldlm_bl_thread_data *bltd = arg;
 
-	{
-		struct ldlm_bl_thread_data *bltd = arg;
+	blp = bltd->bltd_blp;
 
-		blp = bltd->bltd_blp;
+	atomic_inc(&blp->blp_num_threads);
+	atomic_inc(&blp->blp_busy_threads);
 
-		atomic_inc(&blp->blp_num_threads);
-		atomic_inc(&blp->blp_busy_threads);
-
-		complete(&bltd->bltd_comp);
-		/* cannot use bltd after this, it is only on caller's stack */
-	}
+	complete(&bltd->bltd_comp);
+	/* cannot use bltd after this, it is only on caller's stack */
 
 	while (1) {
 		struct l_wait_info lwi = { 0 };
 		struct ldlm_bl_work_item *blwi = NULL;
-		int busy;
+		struct obd_export *exp = NULL;
+		int rc;
 
-		blwi = ldlm_bl_get_work(blp);
-
-		if (!blwi) {
+		rc = ldlm_bl_get_work(blp, &blwi, &exp);
+		if (!rc) {
 			atomic_dec(&blp->blp_busy_threads);
 			l_wait_event_exclusive(blp->blp_waitq,
-					       (blwi = ldlm_bl_get_work(blp)),
+					       ldlm_bl_get_work(blp, &blwi,
+								&exp),
 					       &lwi);
-			busy = atomic_inc_return(&blp->blp_busy_threads);
-		} else {
-			busy = atomic_read(&blp->blp_busy_threads);
+			atomic_inc(&blp->blp_busy_threads);
 		}
 
-		if (!blwi->blwi_ns)
-			/* added by ldlm_cleanup() */
-			break;
-
-		/* Not fatal if racy and have a few too many threads */
-		if (unlikely(busy < blp->blp_max_threads &&
-			     busy >= atomic_read(&blp->blp_num_threads) &&
-			     !blwi->blwi_mem_pressure))
+		if (ldlm_bl_thread_need_create(blp, blwi))
 			/* discard the return value, we tried */
 			ldlm_bl_thread_start(blp);
 
-		if (blwi->blwi_mem_pressure)
-			memory_pressure_set();
+		if (blwi)
+			rc = ldlm_bl_thread_blwi(blp, blwi);
 
-		if (blwi->blwi_count) {
-			int count;
-			/* The special case when we cancel locks in LRU
-			 * asynchronously, we pass the list of locks here.
-			 * Thus locks are marked LDLM_FL_CANCELING, but NOT
-			 * canceled locally yet.
-			 */
-			count = ldlm_cli_cancel_list_local(&blwi->blwi_head,
-							   blwi->blwi_count,
-							   LCF_BL_AST);
-			ldlm_cli_cancel_list(&blwi->blwi_head, count, NULL,
-					     blwi->blwi_flags);
-		} else {
-			ldlm_handle_bl_callback(blwi->blwi_ns, &blwi->blwi_ld,
-						blwi->blwi_lock);
-		}
-		if (blwi->blwi_mem_pressure)
-			memory_pressure_clr();
-
-		if (blwi->blwi_flags & LCF_ASYNC)
-			kfree(blwi);
-		else
-			complete(&blwi->blwi_comp);
+		if (rc == LDLM_ITER_STOP)
+			break;
 	}
 
 	atomic_dec(&blp->blp_busy_threads);
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
index 13fbbedf4945..cf3fc5793377 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
@@ -975,6 +975,10 @@ static int ldlm_pools_recalc(enum ldlm_side client)
 			ldlm_namespace_put(ns);
 		}
 	}
+
+	/* Wake up the blocking threads from time to time. */
+	ldlm_bl_thread_wakeup();
+
 	return time;
 }