1 files changed, 136 insertions, 12 deletions

diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c
index 99c2da632b51..cf8bb2a2f40b 100644
--- a/drivers/staging/lustre/lustre/obdclass/genops.c
+++ b/drivers/staging/lustre/lustre/obdclass/genops.c
@@ -133,7 +133,6 @@ void class_put_type(struct obd_type *type)
 	module_put(type->typ_dt_ops->owner);
 	spin_unlock(&type->obd_type_lock);
 }
-EXPORT_SYMBOL(class_put_type);
 
 #define CLASS_MAX_NAME 1024
 
@@ -166,10 +165,10 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
 	    !type->typ_name)
 		goto failed;
 
-	*(type->typ_dt_ops) = *dt_ops;
+	*type->typ_dt_ops = *dt_ops;
 	/* md_ops is optional */
 	if (md_ops)
-		*(type->typ_md_ops) = *md_ops;
+		*type->typ_md_ops = *md_ops;
 	strcpy(type->typ_name, name);
 	spin_lock_init(&type->obd_type_lock);
 
@@ -391,7 +390,6 @@ int class_name2dev(const char *name)
 
 	return -1;
 }
-EXPORT_SYMBOL(class_name2dev);
 
 struct obd_device *class_name2obd(const char *name)
 {
@@ -421,7 +419,6 @@ int class_uuid2dev(struct obd_uuid *uuid)
 
 	return -1;
 }
-EXPORT_SYMBOL(class_uuid2dev);
 
 /**
  * Get obd device from ::obd_devs[]
@@ -450,7 +447,6 @@ struct obd_device *class_num2obd(int num)
 
 	return obd;
 }
-EXPORT_SYMBOL(class_num2obd);
 
 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
  * specified, then only the client with that uuid is returned,
@@ -509,7 +505,7 @@ struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 			continue;
 		if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 			if (next)
-				*next = i+1;
+				*next = i + 1;
 			read_unlock(&obd_dev_lock);
 			return obd;
 		}
@@ -618,7 +614,7 @@ struct obd_export *class_conn2export(struct lustre_handle *conn)
 	}
 
 	CDEBUG(D_INFO, "looking for export cookie %#llx\n", conn->cookie);
-	export = class_handle2object(conn->cookie);
+	export = class_handle2object(conn->cookie, NULL);
 	return export;
 }
 EXPORT_SYMBOL(class_conn2export);
@@ -817,7 +813,6 @@ void class_unlink_export(struct obd_export *exp)
 	spin_unlock(&exp->exp_obd->obd_dev_lock);
 	class_export_put(exp);
 }
-EXPORT_SYMBOL(class_unlink_export);
 
 /* Import management functions */
 static void class_import_destroy(struct obd_import *imp)
@@ -973,7 +968,6 @@ void __class_export_add_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
 	       lock, exp, lock->l_exp_refs_nr);
 	spin_unlock(&exp->exp_locks_list_guard);
 }
-EXPORT_SYMBOL(__class_export_add_lock_ref);
 
 void __class_export_del_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
 {
@@ -991,7 +985,6 @@ void __class_export_del_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
 	       lock, exp, lock->l_exp_refs_nr);
 	spin_unlock(&exp->exp_locks_list_guard);
 }
-EXPORT_SYMBOL(__class_export_del_lock_ref);
 #endif
 
 /* A connection defines an export context in which preallocation can
@@ -1100,7 +1093,6 @@ EXPORT_SYMBOL(class_fail_export);
 
 #if LUSTRE_TRACKS_LOCK_EXP_REFS
 void (*class_export_dump_hook)(struct obd_export *) = NULL;
-EXPORT_SYMBOL(class_export_dump_hook);
 #endif
 
 /* Total amount of zombies to be destroyed */
@@ -1312,3 +1304,135 @@ void obd_zombie_impexp_stop(void)
 	obd_zombie_impexp_notify();
 	wait_for_completion(&obd_zombie_stop);
 }
+
+struct obd_request_slot_waiter {
+	struct list_head	orsw_entry;
+	wait_queue_head_t	orsw_waitq;
+	bool			orsw_signaled;
+};
+
+static bool obd_request_slot_avail(struct client_obd *cli,
+				   struct obd_request_slot_waiter *orsw)
+{
+	bool avail;
+
+	spin_lock(&cli->cl_loi_list_lock);
+	avail = !!list_empty(&orsw->orsw_entry);
+	spin_unlock(&cli->cl_loi_list_lock);
+
+	return avail;
+};
+
+/*
+ * For network flow control, the RPC sponsor needs to acquire a credit
+ * before sending the RPC. The credits count for a connection is defined
+ * by the "cl_max_rpcs_in_flight". If all the credits are occpuied, then
+ * the subsequent RPC sponsors need to wait until others released their
+ * credits, or the administrator increased the "cl_max_rpcs_in_flight".
+ */
+int obd_get_request_slot(struct client_obd *cli)
+{
+	struct obd_request_slot_waiter orsw;
+	struct l_wait_info lwi;
+	int rc;
+
+	spin_lock(&cli->cl_loi_list_lock);
+	if (cli->cl_r_in_flight < cli->cl_max_rpcs_in_flight) {
+		cli->cl_r_in_flight++;
+		spin_unlock(&cli->cl_loi_list_lock);
+		return 0;
+	}
+
+	init_waitqueue_head(&orsw.orsw_waitq);
+	list_add_tail(&orsw.orsw_entry, &cli->cl_loi_read_list);
+	orsw.orsw_signaled = false;
+	spin_unlock(&cli->cl_loi_list_lock);
+
+	lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
+	rc = l_wait_event(orsw.orsw_waitq,
+			  obd_request_slot_avail(cli, &orsw) ||
+			  orsw.orsw_signaled,
+			  &lwi);
+
+	/*
+	 * Here, we must take the lock to avoid the on-stack 'orsw' to be
+	 * freed but other (such as obd_put_request_slot) is using it.
+	 */
+	spin_lock(&cli->cl_loi_list_lock);
+	if (rc) {
+		if (!orsw.orsw_signaled) {
+			if (list_empty(&orsw.orsw_entry))
+				cli->cl_r_in_flight--;
+			else
+				list_del(&orsw.orsw_entry);
+		}
+	}
+
+	if (orsw.orsw_signaled) {
+		LASSERT(list_empty(&orsw.orsw_entry));
+
+		rc = -EINTR;
+	}
+	spin_unlock(&cli->cl_loi_list_lock);
+
+	return rc;
+}
+EXPORT_SYMBOL(obd_get_request_slot);
+
+void obd_put_request_slot(struct client_obd *cli)
+{
+	struct obd_request_slot_waiter *orsw;
+
+	spin_lock(&cli->cl_loi_list_lock);
+	cli->cl_r_in_flight--;
+
+	/* If there is free slot, wakeup the first waiter. */
+	if (!list_empty(&cli->cl_loi_read_list) &&
+	    likely(cli->cl_r_in_flight < cli->cl_max_rpcs_in_flight)) {
+		orsw = list_entry(cli->cl_loi_read_list.next,
+				  struct obd_request_slot_waiter, orsw_entry);
+		list_del_init(&orsw->orsw_entry);
+		cli->cl_r_in_flight++;
+		wake_up(&orsw->orsw_waitq);
+	}
+	spin_unlock(&cli->cl_loi_list_lock);
+}
+EXPORT_SYMBOL(obd_put_request_slot);
+
+__u32 obd_get_max_rpcs_in_flight(struct client_obd *cli)
+{
+	return cli->cl_max_rpcs_in_flight;
+}
+EXPORT_SYMBOL(obd_get_max_rpcs_in_flight);
+
+int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
+{
+	struct obd_request_slot_waiter *orsw;
+	__u32 old;
+	int diff;
+	int i;
+
+	if (max > OBD_MAX_RIF_MAX || max < 1)
+		return -ERANGE;
+
+	spin_lock(&cli->cl_loi_list_lock);
+	old = cli->cl_max_rpcs_in_flight;
+	cli->cl_max_rpcs_in_flight = max;
+	diff = max - old;
+
+	/* We increase the max_rpcs_in_flight, then wakeup some waiters. */
+	for (i = 0; i < diff; i++) {
+		if (list_empty(&cli->cl_loi_read_list))
+			break;
+
+		orsw = list_entry(cli->cl_loi_read_list.next,
+				  struct obd_request_slot_waiter, orsw_entry);
+		list_del_init(&orsw->orsw_entry);
+		cli->cl_r_in_flight++;
+		wake_up(&orsw->orsw_waitq);
+	}
+	spin_unlock(&cli->cl_loi_list_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(obd_set_max_rpcs_in_flight);