Merge tag 'v3.10-rc1' into stable/for-linus-3.10

Linux 3.10-rc1

* tag 'v3.10-rc1': (12273 commits)
  Linux 3.10-rc1
  [SCSI] qla2xxx: Update firmware link in Kconfig file.
  [SCSI] iscsi class, qla4xxx: fix sess/conn refcounting when find fns are used
  [SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type
  [SCSI] pm80xx: thermal, sas controller config and error handling update
  [SCSI] pm80xx: NCQ error handling changes
  [SCSI] pm80xx: WWN Modification for PM8081/88/89 controllers
  [SCSI] pm80xx: Changed module name and debug messages update
  [SCSI] pm80xx: Firmware flash memory free fix, with addition of new memory region for it
  [SCSI] pm80xx: SPC new firmware changes for device id 0x8081 alone
  [SCSI] pm80xx: Added SPCv/ve specific hardware functionalities and relevant changes in common files
  [SCSI] pm80xx: MSI-X implementation for using 64 interrupts
  [SCSI] pm80xx: Updated common functions common for SPC and SPCv/ve
  [SCSI] pm80xx: Multiple inbound/outbound queue configuration
  [SCSI] pm80xx: Added SPCv/ve specific ids, variables and modify for SPC
  [SCSI] lpfc: fix up Kconfig dependencies
  [SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd
  dm cache: set config value
  dm cache: move config fns
  dm thin: generate event when metadata threshold passed
  ...

1 files changed, 60 insertions, 3 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index b7478d5e7ff..095363eee76 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -948,6 +948,34 @@ void xprt_transmit(struct rpc_task *task)
 	spin_unlock_bh(&xprt->transport_lock);
 }
 
+static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+	set_bit(XPRT_CONGESTED, &xprt->state);
+	rpc_sleep_on(&xprt->backlog, task, NULL);
+}
+
+static void xprt_wake_up_backlog(struct rpc_xprt *xprt)
+{
+	if (rpc_wake_up_next(&xprt->backlog) == NULL)
+		clear_bit(XPRT_CONGESTED, &xprt->state);
+}
+
+static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+	bool ret = false;
+
+	if (!test_bit(XPRT_CONGESTED, &xprt->state))
+		goto out;
+	spin_lock(&xprt->reserve_lock);
+	if (test_bit(XPRT_CONGESTED, &xprt->state)) {
+		rpc_sleep_on(&xprt->backlog, task, NULL);
+		ret = true;
+	}
+	spin_unlock(&xprt->reserve_lock);
+out:
+	return ret;
+}
+
 static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
 {
 	struct rpc_rqst *req = ERR_PTR(-EAGAIN);
@@ -992,7 +1020,7 @@ void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 		task->tk_status = -ENOMEM;
 		break;
 	case -EAGAIN:
-		rpc_sleep_on(&xprt->backlog, task, NULL);
+		xprt_add_backlog(xprt, task);
 		dprintk("RPC:       waiting for request slot\n");
 	default:
 		task->tk_status = -EAGAIN;
@@ -1028,7 +1056,7 @@ static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
 		memset(req, 0, sizeof(*req));	/* mark unused */
 		list_add(&req->rq_list, &xprt->free);
 	}
-	rpc_wake_up_next(&xprt->backlog);
+	xprt_wake_up_backlog(xprt);
 	spin_unlock(&xprt->reserve_lock);
 }
 
@@ -1092,7 +1120,8 @@ EXPORT_SYMBOL_GPL(xprt_free);
  * xprt_reserve - allocate an RPC request slot
  * @task: RPC task requesting a slot allocation
  *
- * If no more slots are available, place the task on the transport's
+ * If the transport is marked as being congested, or if no more
+ * slots are available, place the task on the transport's
  * backlog queue.
  */
 void xprt_reserve(struct rpc_task *task)
@@ -1107,6 +1136,32 @@ void xprt_reserve(struct rpc_task *task)
 	task->tk_status = -EAGAIN;
 	rcu_read_lock();
 	xprt = rcu_dereference(task->tk_client->cl_xprt);
+	if (!xprt_throttle_congested(xprt, task))
+		xprt->ops->alloc_slot(xprt, task);
+	rcu_read_unlock();
+}
+
+/**
+ * xprt_retry_reserve - allocate an RPC request slot
+ * @task: RPC task requesting a slot allocation
+ *
+ * If no more slots are available, place the task on the transport's
+ * backlog queue.
+ * Note that the only difference with xprt_reserve is that we now
+ * ignore the value of the XPRT_CONGESTED flag.
+ */
+void xprt_retry_reserve(struct rpc_task *task)
+{
+	struct rpc_xprt	*xprt;
+
+	task->tk_status = 0;
+	if (task->tk_rqstp != NULL)
+		return;
+
+	task->tk_timeout = 0;
+	task->tk_status = -EAGAIN;
+	rcu_read_lock();
+	xprt = rcu_dereference(task->tk_client->cl_xprt);
 	xprt->ops->alloc_slot(xprt, task);
 	rcu_read_unlock();
 }
@@ -1245,6 +1300,8 @@ found:
 				-PTR_ERR(xprt));
 		goto out;
 	}
+	if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
+		xprt->idle_timeout = 0;
 	INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
 	if (xprt_has_timer(xprt))
 		setup_timer(&xprt->timer, xprt_init_autodisconnect,