11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/net/sunrpc/xprt.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * This is a generic RPC call interface supporting congestion avoidance, 51da177e4SLinus Torvalds * and asynchronous calls. 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * The interface works like this: 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * - When a process places a call, it allocates a request slot if 101da177e4SLinus Torvalds * one is available. Otherwise, it sleeps on the backlog queue 111da177e4SLinus Torvalds * (xprt_reserve). 121da177e4SLinus Torvalds * - Next, the caller puts together the RPC message, stuffs it into 1355aa4f58SChuck Lever * the request struct, and calls xprt_transmit(). 1455aa4f58SChuck Lever * - xprt_transmit sends the message and installs the caller on the 1555aa4f58SChuck Lever * transport's wait list. At the same time, it installs a timer that 161da177e4SLinus Torvalds * is run after the packet's timeout has expired. 171da177e4SLinus Torvalds * - When a packet arrives, the data_ready handler walks the list of 1855aa4f58SChuck Lever * pending requests for that transport. If a matching XID is found, the 191da177e4SLinus Torvalds * caller is woken up, and the timer removed. 201da177e4SLinus Torvalds * - When no reply arrives within the timeout interval, the timer is 211da177e4SLinus Torvalds * fired by the kernel and runs xprt_timer(). It either adjusts the 221da177e4SLinus Torvalds * timeout values (minor timeout) or wakes up the caller with a status 231da177e4SLinus Torvalds * of -ETIMEDOUT. 241da177e4SLinus Torvalds * - When the caller receives a notification from RPC that a reply arrived, 251da177e4SLinus Torvalds * it should release the RPC slot, and process the reply. 261da177e4SLinus Torvalds * If the call timed out, it may choose to retry the operation by 271da177e4SLinus Torvalds * adjusting the initial timeout value, and simply calling rpc_call 281da177e4SLinus Torvalds * again. 291da177e4SLinus Torvalds * 301da177e4SLinus Torvalds * Support for async RPC is done through a set of RPC-specific scheduling 311da177e4SLinus Torvalds * primitives that `transparently' work for processes as well as async 321da177e4SLinus Torvalds * tasks that rely on callbacks. 331da177e4SLinus Torvalds * 341da177e4SLinus Torvalds * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> 3555aa4f58SChuck Lever * 3655aa4f58SChuck Lever * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> 371da177e4SLinus Torvalds */ 381da177e4SLinus Torvalds 39a246b010SChuck Lever #include <linux/module.h> 40a246b010SChuck Lever 411da177e4SLinus Torvalds #include <linux/types.h> 42a246b010SChuck Lever #include <linux/interrupt.h> 431da177e4SLinus Torvalds #include <linux/workqueue.h> 441da177e4SLinus Torvalds #include <linux/random.h> 451da177e4SLinus Torvalds 46a246b010SChuck Lever #include <linux/sunrpc/clnt.h> 4711c556b3SChuck Lever #include <linux/sunrpc/metrics.h> 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds /* 501da177e4SLinus Torvalds * Local variables 511da177e4SLinus Torvalds */ 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds #ifdef RPC_DEBUG 541da177e4SLinus Torvalds # define RPCDBG_FACILITY RPCDBG_XPRT 551da177e4SLinus Torvalds #endif 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds /* 581da177e4SLinus Torvalds * Local functions 591da177e4SLinus Torvalds */ 601da177e4SLinus Torvalds static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); 611da177e4SLinus Torvalds static inline void do_xprt_reserve(struct rpc_task *); 621da177e4SLinus Torvalds static void xprt_connect_status(struct rpc_task *task); 631da177e4SLinus Torvalds static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); 641da177e4SLinus Torvalds 65555ee3afSChuck Lever /* 66555ee3afSChuck Lever * The transport code maintains an estimate on the maximum number of out- 67555ee3afSChuck Lever * standing RPC requests, using a smoothed version of the congestion 68555ee3afSChuck Lever * avoidance implemented in 44BSD. This is basically the Van Jacobson 69555ee3afSChuck Lever * congestion algorithm: If a retransmit occurs, the congestion window is 70555ee3afSChuck Lever * halved; otherwise, it is incremented by 1/cwnd when 71555ee3afSChuck Lever * 72555ee3afSChuck Lever * - a reply is received and 73555ee3afSChuck Lever * - a full number of requests are outstanding and 74555ee3afSChuck Lever * - the congestion window hasn't been updated recently. 75555ee3afSChuck Lever */ 76555ee3afSChuck Lever #define RPC_CWNDSHIFT (8U) 77555ee3afSChuck Lever #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT) 78555ee3afSChuck Lever #define RPC_INITCWND RPC_CWNDSCALE 79555ee3afSChuck Lever #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT) 80555ee3afSChuck Lever 81555ee3afSChuck Lever #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) 821da177e4SLinus Torvalds 8312a80469SChuck Lever /** 8412a80469SChuck Lever * xprt_reserve_xprt - serialize write access to transports 8512a80469SChuck Lever * @task: task that is requesting access to the transport 8612a80469SChuck Lever * 8712a80469SChuck Lever * This prevents mixing the payload of separate requests, and prevents 8812a80469SChuck Lever * transport connects from colliding with writes. No congestion control 8912a80469SChuck Lever * is provided. 901da177e4SLinus Torvalds */ 9112a80469SChuck Lever int xprt_reserve_xprt(struct rpc_task *task) 921da177e4SLinus Torvalds { 9312a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 9412a80469SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 9512a80469SChuck Lever 9612a80469SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 9712a80469SChuck Lever if (task == xprt->snd_task) 9812a80469SChuck Lever return 1; 9912a80469SChuck Lever if (task == NULL) 10012a80469SChuck Lever return 0; 10112a80469SChuck Lever goto out_sleep; 10212a80469SChuck Lever } 10312a80469SChuck Lever xprt->snd_task = task; 10412a80469SChuck Lever if (req) { 10512a80469SChuck Lever req->rq_bytes_sent = 0; 10612a80469SChuck Lever req->rq_ntrans++; 10712a80469SChuck Lever } 10812a80469SChuck Lever return 1; 10912a80469SChuck Lever 11012a80469SChuck Lever out_sleep: 11112a80469SChuck Lever dprintk("RPC: %4d failed to lock transport %p\n", 11212a80469SChuck Lever task->tk_pid, xprt); 11312a80469SChuck Lever task->tk_timeout = 0; 11412a80469SChuck Lever task->tk_status = -EAGAIN; 11512a80469SChuck Lever if (req && req->rq_ntrans) 11612a80469SChuck Lever rpc_sleep_on(&xprt->resend, task, NULL, NULL); 11712a80469SChuck Lever else 11812a80469SChuck Lever rpc_sleep_on(&xprt->sending, task, NULL, NULL); 11912a80469SChuck Lever return 0; 12012a80469SChuck Lever } 12112a80469SChuck Lever 122632e3bdcSTrond Myklebust static void xprt_clear_locked(struct rpc_xprt *xprt) 123632e3bdcSTrond Myklebust { 124632e3bdcSTrond Myklebust xprt->snd_task = NULL; 125632e3bdcSTrond Myklebust if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) { 126632e3bdcSTrond Myklebust smp_mb__before_clear_bit(); 127632e3bdcSTrond Myklebust clear_bit(XPRT_LOCKED, &xprt->state); 128632e3bdcSTrond Myklebust smp_mb__after_clear_bit(); 129632e3bdcSTrond Myklebust } else 130632e3bdcSTrond Myklebust schedule_work(&xprt->task_cleanup); 131632e3bdcSTrond Myklebust } 132632e3bdcSTrond Myklebust 13312a80469SChuck Lever /* 13412a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 13512a80469SChuck Lever * @task: task that is requesting access to the transport 13612a80469SChuck Lever * 13712a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 13812a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 13912a80469SChuck Lever * woken up and given access to the transport. 14012a80469SChuck Lever */ 14112a80469SChuck Lever int xprt_reserve_xprt_cong(struct rpc_task *task) 14212a80469SChuck Lever { 14312a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 1441da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 1451da177e4SLinus Torvalds 1462226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 1471da177e4SLinus Torvalds if (task == xprt->snd_task) 1481da177e4SLinus Torvalds return 1; 1491da177e4SLinus Torvalds goto out_sleep; 1501da177e4SLinus Torvalds } 15112a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 1521da177e4SLinus Torvalds xprt->snd_task = task; 1531da177e4SLinus Torvalds if (req) { 1541da177e4SLinus Torvalds req->rq_bytes_sent = 0; 1551da177e4SLinus Torvalds req->rq_ntrans++; 1561da177e4SLinus Torvalds } 1571da177e4SLinus Torvalds return 1; 1581da177e4SLinus Torvalds } 159632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 1601da177e4SLinus Torvalds out_sleep: 16155aa4f58SChuck Lever dprintk("RPC: %4d failed to lock transport %p\n", task->tk_pid, xprt); 1621da177e4SLinus Torvalds task->tk_timeout = 0; 1631da177e4SLinus Torvalds task->tk_status = -EAGAIN; 1641da177e4SLinus Torvalds if (req && req->rq_ntrans) 1651da177e4SLinus Torvalds rpc_sleep_on(&xprt->resend, task, NULL, NULL); 1661da177e4SLinus Torvalds else 1671da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 1681da177e4SLinus Torvalds return 0; 1691da177e4SLinus Torvalds } 1701da177e4SLinus Torvalds 17112a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 1721da177e4SLinus Torvalds { 1731da177e4SLinus Torvalds int retval; 1741da177e4SLinus Torvalds 1754a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 17612a80469SChuck Lever retval = xprt->ops->reserve_xprt(task); 1774a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 1781da177e4SLinus Torvalds return retval; 1791da177e4SLinus Torvalds } 1801da177e4SLinus Torvalds 18112a80469SChuck Lever static void __xprt_lock_write_next(struct rpc_xprt *xprt) 1821da177e4SLinus Torvalds { 1831da177e4SLinus Torvalds struct rpc_task *task; 18449e9a890SChuck Lever struct rpc_rqst *req; 18549e9a890SChuck Lever 18649e9a890SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 18749e9a890SChuck Lever return; 18849e9a890SChuck Lever 18949e9a890SChuck Lever task = rpc_wake_up_next(&xprt->resend); 19049e9a890SChuck Lever if (!task) { 19149e9a890SChuck Lever task = rpc_wake_up_next(&xprt->sending); 19249e9a890SChuck Lever if (!task) 19349e9a890SChuck Lever goto out_unlock; 19449e9a890SChuck Lever } 19549e9a890SChuck Lever 19649e9a890SChuck Lever req = task->tk_rqstp; 19749e9a890SChuck Lever xprt->snd_task = task; 19849e9a890SChuck Lever if (req) { 19949e9a890SChuck Lever req->rq_bytes_sent = 0; 20049e9a890SChuck Lever req->rq_ntrans++; 20149e9a890SChuck Lever } 20249e9a890SChuck Lever return; 20349e9a890SChuck Lever 20449e9a890SChuck Lever out_unlock: 205632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 20649e9a890SChuck Lever } 20749e9a890SChuck Lever 20849e9a890SChuck Lever static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 20949e9a890SChuck Lever { 21049e9a890SChuck Lever struct rpc_task *task; 2111da177e4SLinus Torvalds 2122226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 2131da177e4SLinus Torvalds return; 21449e9a890SChuck Lever if (RPCXPRT_CONGESTED(xprt)) 2151da177e4SLinus Torvalds goto out_unlock; 2161da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->resend); 2171da177e4SLinus Torvalds if (!task) { 2181da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->sending); 2191da177e4SLinus Torvalds if (!task) 2201da177e4SLinus Torvalds goto out_unlock; 2211da177e4SLinus Torvalds } 22249e9a890SChuck Lever if (__xprt_get_cong(xprt, task)) { 2231da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2241da177e4SLinus Torvalds xprt->snd_task = task; 2251da177e4SLinus Torvalds if (req) { 2261da177e4SLinus Torvalds req->rq_bytes_sent = 0; 2271da177e4SLinus Torvalds req->rq_ntrans++; 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds return; 2301da177e4SLinus Torvalds } 2311da177e4SLinus Torvalds out_unlock: 232632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2331da177e4SLinus Torvalds } 2341da177e4SLinus Torvalds 23549e9a890SChuck Lever /** 23649e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 23749e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 23849e9a890SChuck Lever * @task: task that is releasing access to the transport 23949e9a890SChuck Lever * 24049e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 2411da177e4SLinus Torvalds */ 24249e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 2431da177e4SLinus Torvalds { 2441da177e4SLinus Torvalds if (xprt->snd_task == task) { 245632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2461da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 25049e9a890SChuck Lever /** 25149e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 25249e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 25349e9a890SChuck Lever * @task: task that is releasing access to the transport 25449e9a890SChuck Lever * 25549e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 25649e9a890SChuck Lever * transport if the transport's congestion window allows it. 25749e9a890SChuck Lever */ 25849e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 25949e9a890SChuck Lever { 26049e9a890SChuck Lever if (xprt->snd_task == task) { 261632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 26249e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 26349e9a890SChuck Lever } 26449e9a890SChuck Lever } 26549e9a890SChuck Lever 26649e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 2671da177e4SLinus Torvalds { 2684a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 26949e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 2704a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2711da177e4SLinus Torvalds } 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds /* 2741da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 2751da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 2761da177e4SLinus Torvalds */ 2771da177e4SLinus Torvalds static int 2781da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 2791da177e4SLinus Torvalds { 2801da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds if (req->rq_cong) 2831da177e4SLinus Torvalds return 1; 2841da177e4SLinus Torvalds dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n", 2851da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 2861da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 2871da177e4SLinus Torvalds return 0; 2881da177e4SLinus Torvalds req->rq_cong = 1; 2891da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 2901da177e4SLinus Torvalds return 1; 2911da177e4SLinus Torvalds } 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds /* 2941da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 2951da177e4SLinus Torvalds * that has been sleeping due to congestion 2961da177e4SLinus Torvalds */ 2971da177e4SLinus Torvalds static void 2981da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 2991da177e4SLinus Torvalds { 3001da177e4SLinus Torvalds if (!req->rq_cong) 3011da177e4SLinus Torvalds return; 3021da177e4SLinus Torvalds req->rq_cong = 0; 3031da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 30449e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3051da177e4SLinus Torvalds } 3061da177e4SLinus Torvalds 30746c0ee8bSChuck Lever /** 308a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 309a58dd398SChuck Lever * @task: RPC request that recently completed 310a58dd398SChuck Lever * 311a58dd398SChuck Lever * Useful for transports that require congestion control. 312a58dd398SChuck Lever */ 313a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 314a58dd398SChuck Lever { 315a58dd398SChuck Lever __xprt_put_cong(task->tk_xprt, task->tk_rqstp); 316a58dd398SChuck Lever } 317a58dd398SChuck Lever 318a58dd398SChuck Lever /** 31946c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 32046c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 32146c0ee8bSChuck Lever * @result: result code of completed RPC request 32246c0ee8bSChuck Lever * 3231da177e4SLinus Torvalds * We use a time-smoothed congestion estimator to avoid heavy oscillation. 3241da177e4SLinus Torvalds */ 32546c0ee8bSChuck Lever void xprt_adjust_cwnd(struct rpc_task *task, int result) 3261da177e4SLinus Torvalds { 32746c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 32846c0ee8bSChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 32946c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 3321da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 3331da177e4SLinus Torvalds * the result gets rounded properly. */ 3341da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 3351da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 3361da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 33749e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3381da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 3391da177e4SLinus Torvalds cwnd >>= 1; 3401da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 3411da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 3421da177e4SLinus Torvalds } 3431da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 3441da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 3451da177e4SLinus Torvalds xprt->cwnd = cwnd; 34646c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 3471da177e4SLinus Torvalds } 3481da177e4SLinus Torvalds 34944fbac22SChuck Lever /** 35044fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 35144fbac22SChuck Lever * @xprt: transport with waiting tasks 35244fbac22SChuck Lever * @status: result code to plant in each task before waking it 35344fbac22SChuck Lever * 35444fbac22SChuck Lever */ 35544fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 35644fbac22SChuck Lever { 35744fbac22SChuck Lever if (status < 0) 35844fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 35944fbac22SChuck Lever else 36044fbac22SChuck Lever rpc_wake_up(&xprt->pending); 36144fbac22SChuck Lever } 36244fbac22SChuck Lever 363c7b2cae8SChuck Lever /** 364c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 365c7b2cae8SChuck Lever * @task: task to be put to sleep 366c7b2cae8SChuck Lever * 367c7b2cae8SChuck Lever */ 368c7b2cae8SChuck Lever void xprt_wait_for_buffer_space(struct rpc_task *task) 369c7b2cae8SChuck Lever { 370c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 371c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 372c7b2cae8SChuck Lever 373c7b2cae8SChuck Lever task->tk_timeout = req->rq_timeout; 374c7b2cae8SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, NULL); 375c7b2cae8SChuck Lever } 376c7b2cae8SChuck Lever 377c7b2cae8SChuck Lever /** 378c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 379c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 380c7b2cae8SChuck Lever * 381c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 382c7b2cae8SChuck Lever */ 383c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 384c7b2cae8SChuck Lever { 385c7b2cae8SChuck Lever if (unlikely(xprt->shutdown)) 386c7b2cae8SChuck Lever return; 387c7b2cae8SChuck Lever 388c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 389c7b2cae8SChuck Lever if (xprt->snd_task) { 390c7b2cae8SChuck Lever dprintk("RPC: write space: waking waiting task on xprt %p\n", 391c7b2cae8SChuck Lever xprt); 392c7b2cae8SChuck Lever rpc_wake_up_task(xprt->snd_task); 393c7b2cae8SChuck Lever } 394c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 395c7b2cae8SChuck Lever } 396c7b2cae8SChuck Lever 397fe3aca29SChuck Lever /** 398fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 399fe3aca29SChuck Lever * @task: task whose timeout is to be set 400fe3aca29SChuck Lever * 401fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 402fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 403fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 404fe3aca29SChuck Lever */ 405fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 406fe3aca29SChuck Lever { 407fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 408fe3aca29SChuck Lever } 409fe3aca29SChuck Lever 410fe3aca29SChuck Lever /* 411fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 412fe3aca29SChuck Lever * @task: task whose timeout is to be set 413fe3aca29SChuck Lever * 414fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 415fe3aca29SChuck Lever */ 416fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 417fe3aca29SChuck Lever { 418fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 419fe3aca29SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 420fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 421fe3aca29SChuck Lever unsigned long max_timeout = req->rq_xprt->timeout.to_maxval; 422fe3aca29SChuck Lever 423fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 424fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 425fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 426fe3aca29SChuck Lever task->tk_timeout = max_timeout; 427fe3aca29SChuck Lever } 428fe3aca29SChuck Lever 4291da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 4301da177e4SLinus Torvalds { 4311da177e4SLinus Torvalds struct rpc_timeout *to = &req->rq_xprt->timeout; 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 4341da177e4SLinus Torvalds if (to->to_exponential) 4351da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 4361da177e4SLinus Torvalds else 4371da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 4381da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 4391da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 4401da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 4411da177e4SLinus Torvalds } 4421da177e4SLinus Torvalds 4439903cd1cSChuck Lever /** 4449903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 4459903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 4469903cd1cSChuck Lever * 4471da177e4SLinus Torvalds */ 4481da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 4491da177e4SLinus Torvalds { 4501da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 4511da177e4SLinus Torvalds struct rpc_timeout *to = &xprt->timeout; 4521da177e4SLinus Torvalds int status = 0; 4531da177e4SLinus Torvalds 4541da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 4551da177e4SLinus Torvalds if (to->to_exponential) 4561da177e4SLinus Torvalds req->rq_timeout <<= 1; 4571da177e4SLinus Torvalds else 4581da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 4591da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 4601da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 4611da177e4SLinus Torvalds req->rq_retries++; 4621da177e4SLinus Torvalds pprintk("RPC: %lu retrans\n", jiffies); 4631da177e4SLinus Torvalds } else { 4641da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 4651da177e4SLinus Torvalds req->rq_retries = 0; 4661da177e4SLinus Torvalds xprt_reset_majortimeo(req); 4671da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 4684a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 4691da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 4704a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 4711da177e4SLinus Torvalds pprintk("RPC: %lu timeout\n", jiffies); 4721da177e4SLinus Torvalds status = -ETIMEDOUT; 4731da177e4SLinus Torvalds } 4741da177e4SLinus Torvalds 4751da177e4SLinus Torvalds if (req->rq_timeout == 0) { 4761da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 4771da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 4781da177e4SLinus Torvalds } 4791da177e4SLinus Torvalds return status; 4801da177e4SLinus Torvalds } 4811da177e4SLinus Torvalds 48255aa4f58SChuck Lever static void xprt_autoclose(void *args) 4831da177e4SLinus Torvalds { 4841da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)args; 4851da177e4SLinus Torvalds 4861da177e4SLinus Torvalds xprt_disconnect(xprt); 487a246b010SChuck Lever xprt->ops->close(xprt); 4881da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 4891da177e4SLinus Torvalds } 4901da177e4SLinus Torvalds 4919903cd1cSChuck Lever /** 4929903cd1cSChuck Lever * xprt_disconnect - mark a transport as disconnected 4939903cd1cSChuck Lever * @xprt: transport to flag for disconnect 4949903cd1cSChuck Lever * 4951da177e4SLinus Torvalds */ 496a246b010SChuck Lever void xprt_disconnect(struct rpc_xprt *xprt) 4971da177e4SLinus Torvalds { 4981da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 4994a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5001da177e4SLinus Torvalds xprt_clear_connected(xprt); 50144fbac22SChuck Lever xprt_wake_pending_tasks(xprt, -ENOTCONN); 5024a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5031da177e4SLinus Torvalds } 5041da177e4SLinus Torvalds 5051da177e4SLinus Torvalds static void 5061da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 5071da177e4SLinus Torvalds { 5081da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 5091da177e4SLinus Torvalds 5104a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 5111da177e4SLinus Torvalds if (!list_empty(&xprt->recv) || xprt->shutdown) 5121da177e4SLinus Torvalds goto out_abort; 5132226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 5141da177e4SLinus Torvalds goto out_abort; 5154a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 5162226feb6SChuck Lever if (xprt_connecting(xprt)) 5171da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 5181da177e4SLinus Torvalds else 5191da177e4SLinus Torvalds schedule_work(&xprt->task_cleanup); 5201da177e4SLinus Torvalds return; 5211da177e4SLinus Torvalds out_abort: 5224a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 5231da177e4SLinus Torvalds } 5241da177e4SLinus Torvalds 5259903cd1cSChuck Lever /** 5269903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 5279903cd1cSChuck Lever * @task: RPC task that is requesting the connect 5281da177e4SLinus Torvalds * 5291da177e4SLinus Torvalds */ 5301da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 5311da177e4SLinus Torvalds { 5321da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 5331da177e4SLinus Torvalds 5341da177e4SLinus Torvalds dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid, 5351da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 5361da177e4SLinus Torvalds 5371da177e4SLinus Torvalds if (!xprt->addr.sin_port) { 5381da177e4SLinus Torvalds task->tk_status = -EIO; 5391da177e4SLinus Torvalds return; 5401da177e4SLinus Torvalds } 5411da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 5421da177e4SLinus Torvalds return; 5431da177e4SLinus Torvalds if (xprt_connected(xprt)) 544a246b010SChuck Lever xprt_release_write(xprt, task); 545a246b010SChuck Lever else { 5461da177e4SLinus Torvalds if (task->tk_rqstp) 5471da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 5481da177e4SLinus Torvalds 54903bf4b70SChuck Lever task->tk_timeout = xprt->connect_timeout; 5501da177e4SLinus Torvalds rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL); 551262ca07dSChuck Lever xprt->stat.connect_start = jiffies; 552a246b010SChuck Lever xprt->ops->connect(task); 5531da177e4SLinus Torvalds } 5541da177e4SLinus Torvalds return; 5551da177e4SLinus Torvalds } 5561da177e4SLinus Torvalds 5579903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 5581da177e4SLinus Torvalds { 5591da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 5601da177e4SLinus Torvalds 5611da177e4SLinus Torvalds if (task->tk_status >= 0) { 562262ca07dSChuck Lever xprt->stat.connect_count++; 563262ca07dSChuck Lever xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; 5641da177e4SLinus Torvalds dprintk("RPC: %4d xprt_connect_status: connection established\n", 5651da177e4SLinus Torvalds task->tk_pid); 5661da177e4SLinus Torvalds return; 5671da177e4SLinus Torvalds } 5681da177e4SLinus Torvalds 5691da177e4SLinus Torvalds switch (task->tk_status) { 5701da177e4SLinus Torvalds case -ECONNREFUSED: 5711da177e4SLinus Torvalds case -ECONNRESET: 57223475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: server %s refused connection\n", 57323475d66SChuck Lever task->tk_pid, task->tk_client->cl_server); 57423475d66SChuck Lever break; 5751da177e4SLinus Torvalds case -ENOTCONN: 57623475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: connection broken\n", 57723475d66SChuck Lever task->tk_pid); 57823475d66SChuck Lever break; 5791da177e4SLinus Torvalds case -ETIMEDOUT: 58023475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: connect attempt timed out\n", 5811da177e4SLinus Torvalds task->tk_pid); 5821da177e4SLinus Torvalds break; 5831da177e4SLinus Torvalds default: 58423475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: error %d connecting to server %s\n", 58523475d66SChuck Lever task->tk_pid, -task->tk_status, task->tk_client->cl_server); 5861da177e4SLinus Torvalds xprt_release_write(xprt, task); 58723475d66SChuck Lever task->tk_status = -EIO; 58823475d66SChuck Lever return; 58923475d66SChuck Lever } 59023475d66SChuck Lever 59123475d66SChuck Lever /* if soft mounted, just cause this RPC to fail */ 59223475d66SChuck Lever if (RPC_IS_SOFT(task)) { 59323475d66SChuck Lever xprt_release_write(xprt, task); 59423475d66SChuck Lever task->tk_status = -EIO; 59523475d66SChuck Lever } 5961da177e4SLinus Torvalds } 5971da177e4SLinus Torvalds 5989903cd1cSChuck Lever /** 5999903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 6009903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 6019903cd1cSChuck Lever * @xid: RPC XID of incoming reply 6029903cd1cSChuck Lever * 6031da177e4SLinus Torvalds */ 604a246b010SChuck Lever struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid) 6051da177e4SLinus Torvalds { 6061da177e4SLinus Torvalds struct list_head *pos; 6071da177e4SLinus Torvalds 6081da177e4SLinus Torvalds list_for_each(pos, &xprt->recv) { 6091da177e4SLinus Torvalds struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list); 610262ca07dSChuck Lever if (entry->rq_xid == xid) 611262ca07dSChuck Lever return entry; 6121da177e4SLinus Torvalds } 613262ca07dSChuck Lever xprt->stat.bad_xids++; 614262ca07dSChuck Lever return NULL; 6151da177e4SLinus Torvalds } 6161da177e4SLinus Torvalds 6179903cd1cSChuck Lever /** 6181570c1e4SChuck Lever * xprt_update_rtt - update an RPC client's RTT state after receiving a reply 6191570c1e4SChuck Lever * @task: RPC request that recently completed 6209903cd1cSChuck Lever * 6211da177e4SLinus Torvalds */ 6221570c1e4SChuck Lever void xprt_update_rtt(struct rpc_task *task) 6231da177e4SLinus Torvalds { 6241570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 6251570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 6261da177e4SLinus Torvalds unsigned timer = task->tk_msg.rpc_proc->p_timer; 6271570c1e4SChuck Lever 6281da177e4SLinus Torvalds if (timer) { 6291da177e4SLinus Torvalds if (req->rq_ntrans == 1) 6301570c1e4SChuck Lever rpc_update_rtt(rtt, timer, 6311da177e4SLinus Torvalds (long)jiffies - req->rq_xtime); 6321570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 6331da177e4SLinus Torvalds } 6341da177e4SLinus Torvalds } 6351da177e4SLinus Torvalds 6361570c1e4SChuck Lever /** 6371570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 6381570c1e4SChuck Lever * @task: RPC request that recently completed 6391570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 6401570c1e4SChuck Lever * 6411570c1e4SChuck Lever * Caller holds transport lock. 6421570c1e4SChuck Lever */ 6431570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 6441570c1e4SChuck Lever { 6451570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 6461da177e4SLinus Torvalds 6471570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 6481570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 6491da177e4SLinus Torvalds 650262ca07dSChuck Lever task->tk_xprt->stat.recvs++; 651ef759a2eSChuck Lever task->tk_rtt = (long)jiffies - req->rq_xtime; 652ef759a2eSChuck Lever 6531da177e4SLinus Torvalds list_del_init(&req->rq_list); 65443ac3f29STrond Myklebust /* Ensure all writes are done before we update req->rq_received */ 65543ac3f29STrond Myklebust smp_wmb(); 6561da177e4SLinus Torvalds req->rq_received = req->rq_private_buf.len = copied; 6571da177e4SLinus Torvalds rpc_wake_up_task(task); 6581da177e4SLinus Torvalds } 6591da177e4SLinus Torvalds 66046c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 6611da177e4SLinus Torvalds { 6621da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 6631da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 6641da177e4SLinus Torvalds 66546c0ee8bSChuck Lever dprintk("RPC: %4d xprt_timer\n", task->tk_pid); 66646c0ee8bSChuck Lever 6674a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 66846c0ee8bSChuck Lever if (!req->rq_received) { 66946c0ee8bSChuck Lever if (xprt->ops->timer) 67046c0ee8bSChuck Lever xprt->ops->timer(task); 6711da177e4SLinus Torvalds task->tk_status = -ETIMEDOUT; 67246c0ee8bSChuck Lever } 6731da177e4SLinus Torvalds task->tk_timeout = 0; 6741da177e4SLinus Torvalds rpc_wake_up_task(task); 6754a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6761da177e4SLinus Torvalds } 6771da177e4SLinus Torvalds 6789903cd1cSChuck Lever /** 6799903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 6809903cd1cSChuck Lever * @task: RPC task about to send a request 6819903cd1cSChuck Lever * 6821da177e4SLinus Torvalds */ 6839903cd1cSChuck Lever int xprt_prepare_transmit(struct rpc_task *task) 6841da177e4SLinus Torvalds { 6851da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 6861da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 6871da177e4SLinus Torvalds int err = 0; 6881da177e4SLinus Torvalds 6891da177e4SLinus Torvalds dprintk("RPC: %4d xprt_prepare_transmit\n", task->tk_pid); 6901da177e4SLinus Torvalds 6914a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 6921da177e4SLinus Torvalds if (req->rq_received && !req->rq_bytes_sent) { 6931da177e4SLinus Torvalds err = req->rq_received; 6941da177e4SLinus Torvalds goto out_unlock; 6951da177e4SLinus Torvalds } 69612a80469SChuck Lever if (!xprt->ops->reserve_xprt(task)) { 6971da177e4SLinus Torvalds err = -EAGAIN; 6981da177e4SLinus Torvalds goto out_unlock; 6991da177e4SLinus Torvalds } 7001da177e4SLinus Torvalds 7011da177e4SLinus Torvalds if (!xprt_connected(xprt)) { 7021da177e4SLinus Torvalds err = -ENOTCONN; 7031da177e4SLinus Torvalds goto out_unlock; 7041da177e4SLinus Torvalds } 7051da177e4SLinus Torvalds out_unlock: 7064a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 7071da177e4SLinus Torvalds return err; 7081da177e4SLinus Torvalds } 7091da177e4SLinus Torvalds 7105e5ce5beSTrond Myklebust void 7115e5ce5beSTrond Myklebust xprt_abort_transmit(struct rpc_task *task) 7125e5ce5beSTrond Myklebust { 7135e5ce5beSTrond Myklebust struct rpc_xprt *xprt = task->tk_xprt; 7145e5ce5beSTrond Myklebust 7155e5ce5beSTrond Myklebust xprt_release_write(xprt, task); 7165e5ce5beSTrond Myklebust } 7175e5ce5beSTrond Myklebust 7189903cd1cSChuck Lever /** 7199903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 7209903cd1cSChuck Lever * @task: controlling RPC task 7219903cd1cSChuck Lever * 7229903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 7239903cd1cSChuck Lever */ 7249903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 7251da177e4SLinus Torvalds { 7261da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 7271da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 728a246b010SChuck Lever int status; 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 7311da177e4SLinus Torvalds 7321da177e4SLinus Torvalds if (!req->rq_received) { 7331da177e4SLinus Torvalds if (list_empty(&req->rq_list)) { 7344a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 7351da177e4SLinus Torvalds /* Update the softirq receive buffer */ 7361da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 7371da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 7381da177e4SLinus Torvalds /* Add request to the receive list */ 7391da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 7404a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 7411da177e4SLinus Torvalds xprt_reset_majortimeo(req); 7420f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 7430f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 7441da177e4SLinus Torvalds } 7451da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 7461da177e4SLinus Torvalds return; 7471da177e4SLinus Torvalds 748a246b010SChuck Lever status = xprt->ops->send_request(task); 749fe3aca29SChuck Lever if (status == 0) { 750fe3aca29SChuck Lever dprintk("RPC: %4d xmit complete\n", task->tk_pid); 751fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 752262ca07dSChuck Lever 753fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 754262ca07dSChuck Lever 755262ca07dSChuck Lever xprt->stat.sends++; 756262ca07dSChuck Lever xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; 757262ca07dSChuck Lever xprt->stat.bklog_u += xprt->backlog.qlen; 758262ca07dSChuck Lever 759fe3aca29SChuck Lever /* Don't race with disconnect */ 760fe3aca29SChuck Lever if (!xprt_connected(xprt)) 761fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 762fe3aca29SChuck Lever else if (!req->rq_received) 763fe3aca29SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer); 764262ca07dSChuck Lever 76549e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 766fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 767fe3aca29SChuck Lever return; 768fe3aca29SChuck Lever } 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds /* Note: at this point, task->tk_sleeping has not yet been set, 7711da177e4SLinus Torvalds * hence there is no danger of the waking up task being put on 7721da177e4SLinus Torvalds * schedq, and being picked up by a parallel run of rpciod(). 7731da177e4SLinus Torvalds */ 7741da177e4SLinus Torvalds task->tk_status = status; 7751da177e4SLinus Torvalds 7761da177e4SLinus Torvalds switch (status) { 7771da177e4SLinus Torvalds case -ECONNREFUSED: 7781da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 779a246b010SChuck Lever case -EAGAIN: 7801da177e4SLinus Torvalds case -ENOTCONN: 7811da177e4SLinus Torvalds return; 7821da177e4SLinus Torvalds default: 78343118c29SChuck Lever break; 7841da177e4SLinus Torvalds } 7851da177e4SLinus Torvalds xprt_release_write(xprt, task); 7861da177e4SLinus Torvalds return; 7871da177e4SLinus Torvalds } 7881da177e4SLinus Torvalds 7899903cd1cSChuck Lever static inline void do_xprt_reserve(struct rpc_task *task) 7901da177e4SLinus Torvalds { 7911da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 7921da177e4SLinus Torvalds 7931da177e4SLinus Torvalds task->tk_status = 0; 7941da177e4SLinus Torvalds if (task->tk_rqstp) 7951da177e4SLinus Torvalds return; 7961da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 7971da177e4SLinus Torvalds struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 7981da177e4SLinus Torvalds list_del_init(&req->rq_list); 7991da177e4SLinus Torvalds task->tk_rqstp = req; 8001da177e4SLinus Torvalds xprt_request_init(task, xprt); 8011da177e4SLinus Torvalds return; 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds dprintk("RPC: waiting for request slot\n"); 8041da177e4SLinus Torvalds task->tk_status = -EAGAIN; 8051da177e4SLinus Torvalds task->tk_timeout = 0; 8061da177e4SLinus Torvalds rpc_sleep_on(&xprt->backlog, task, NULL, NULL); 8071da177e4SLinus Torvalds } 8081da177e4SLinus Torvalds 8099903cd1cSChuck Lever /** 8109903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 8119903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 8129903cd1cSChuck Lever * 8139903cd1cSChuck Lever * If no more slots are available, place the task on the transport's 8149903cd1cSChuck Lever * backlog queue. 8159903cd1cSChuck Lever */ 8169903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 8171da177e4SLinus Torvalds { 8181da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 8191da177e4SLinus Torvalds 8201da177e4SLinus Torvalds task->tk_status = -EIO; 8215dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 8221da177e4SLinus Torvalds do_xprt_reserve(task); 8235dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 8241da177e4SLinus Torvalds } 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt) 8271da177e4SLinus Torvalds { 8281da177e4SLinus Torvalds return xprt->xid++; 8291da177e4SLinus Torvalds } 8301da177e4SLinus Torvalds 8311da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 8321da177e4SLinus Torvalds { 8331da177e4SLinus Torvalds get_random_bytes(&xprt->xid, sizeof(xprt->xid)); 8341da177e4SLinus Torvalds } 8351da177e4SLinus Torvalds 8369903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 8371da177e4SLinus Torvalds { 8381da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8391da177e4SLinus Torvalds 8401da177e4SLinus Torvalds req->rq_timeout = xprt->timeout.to_initval; 8411da177e4SLinus Torvalds req->rq_task = task; 8421da177e4SLinus Torvalds req->rq_xprt = xprt; 84302107148SChuck Lever req->rq_buffer = NULL; 84402107148SChuck Lever req->rq_bufsize = 0; 8451da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 846ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf = NULL; 8471da177e4SLinus Torvalds dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid, 8481da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 8491da177e4SLinus Torvalds } 8501da177e4SLinus Torvalds 8519903cd1cSChuck Lever /** 8529903cd1cSChuck Lever * xprt_release - release an RPC request slot 8539903cd1cSChuck Lever * @task: task which is finished with the slot 8549903cd1cSChuck Lever * 8551da177e4SLinus Torvalds */ 8569903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 8571da177e4SLinus Torvalds { 8581da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 8591da177e4SLinus Torvalds struct rpc_rqst *req; 8601da177e4SLinus Torvalds 8611da177e4SLinus Torvalds if (!(req = task->tk_rqstp)) 8621da177e4SLinus Torvalds return; 86311c556b3SChuck Lever rpc_count_iostats(task); 8644a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 86549e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 866a58dd398SChuck Lever if (xprt->ops->release_request) 867a58dd398SChuck Lever xprt->ops->release_request(task); 8681da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 8691da177e4SLinus Torvalds list_del(&req->rq_list); 8701da177e4SLinus Torvalds xprt->last_used = jiffies; 8710065db32STrond Myklebust if (list_empty(&xprt->recv)) 872a246b010SChuck Lever mod_timer(&xprt->timer, 87303bf4b70SChuck Lever xprt->last_used + xprt->idle_timeout); 8744a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 87502107148SChuck Lever xprt->ops->buf_free(task); 8761da177e4SLinus Torvalds task->tk_rqstp = NULL; 877ead5e1c2SJ. Bruce Fields if (req->rq_release_snd_buf) 878ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf(req); 8791da177e4SLinus Torvalds memset(req, 0, sizeof(*req)); /* mark unused */ 8801da177e4SLinus Torvalds 8811da177e4SLinus Torvalds dprintk("RPC: %4d release request %p\n", task->tk_pid, req); 8821da177e4SLinus Torvalds 8835dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 8841da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 885555ee3afSChuck Lever rpc_wake_up_next(&xprt->backlog); 8865dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 8871da177e4SLinus Torvalds } 8881da177e4SLinus Torvalds 8899903cd1cSChuck Lever /** 8909903cd1cSChuck Lever * xprt_set_timeout - set constant RPC timeout 8919903cd1cSChuck Lever * @to: RPC timeout parameters to set up 8929903cd1cSChuck Lever * @retr: number of retries 8939903cd1cSChuck Lever * @incr: amount of increase after each retry 8949903cd1cSChuck Lever * 8951da177e4SLinus Torvalds */ 8969903cd1cSChuck Lever void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr) 8971da177e4SLinus Torvalds { 8981da177e4SLinus Torvalds to->to_initval = 8991da177e4SLinus Torvalds to->to_increment = incr; 900eab5c084SChuck Lever to->to_maxval = to->to_initval + (incr * retr); 9011da177e4SLinus Torvalds to->to_retries = retr; 9021da177e4SLinus Torvalds to->to_exponential = 0; 9031da177e4SLinus Torvalds } 9041da177e4SLinus Torvalds 9059903cd1cSChuck Lever static struct rpc_xprt *xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to) 9061da177e4SLinus Torvalds { 907a246b010SChuck Lever int result; 9081da177e4SLinus Torvalds struct rpc_xprt *xprt; 9091da177e4SLinus Torvalds struct rpc_rqst *req; 9101da177e4SLinus Torvalds 9111da177e4SLinus Torvalds if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL) 9121da177e4SLinus Torvalds return ERR_PTR(-ENOMEM); 9131da177e4SLinus Torvalds memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */ 9141da177e4SLinus Torvalds 9151da177e4SLinus Torvalds xprt->addr = *ap; 916a246b010SChuck Lever 917a246b010SChuck Lever switch (proto) { 918a246b010SChuck Lever case IPPROTO_UDP: 919a246b010SChuck Lever result = xs_setup_udp(xprt, to); 920a246b010SChuck Lever break; 921a246b010SChuck Lever case IPPROTO_TCP: 922a246b010SChuck Lever result = xs_setup_tcp(xprt, to); 923a246b010SChuck Lever break; 924a246b010SChuck Lever default: 925a246b010SChuck Lever printk(KERN_ERR "RPC: unrecognized transport protocol: %d\n", 926a246b010SChuck Lever proto); 927a246b010SChuck Lever result = -EIO; 928a246b010SChuck Lever break; 9291da177e4SLinus Torvalds } 930a246b010SChuck Lever if (result) { 931a246b010SChuck Lever kfree(xprt); 932a246b010SChuck Lever return ERR_PTR(result); 933a246b010SChuck Lever } 934a246b010SChuck Lever 9354a0f8c04SChuck Lever spin_lock_init(&xprt->transport_lock); 9365dc07727SChuck Lever spin_lock_init(&xprt->reserve_lock); 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds INIT_LIST_HEAD(&xprt->free); 9391da177e4SLinus Torvalds INIT_LIST_HEAD(&xprt->recv); 94055aa4f58SChuck Lever INIT_WORK(&xprt->task_cleanup, xprt_autoclose, xprt); 9411da177e4SLinus Torvalds init_timer(&xprt->timer); 9421da177e4SLinus Torvalds xprt->timer.function = xprt_init_autodisconnect; 9431da177e4SLinus Torvalds xprt->timer.data = (unsigned long) xprt; 9441da177e4SLinus Torvalds xprt->last_used = jiffies; 945555ee3afSChuck Lever xprt->cwnd = RPC_INITCWND; 9461da177e4SLinus Torvalds 9471da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 9481da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->sending, "xprt_sending"); 9491da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->resend, "xprt_resend"); 9501da177e4SLinus Torvalds rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 9511da177e4SLinus Torvalds 9521da177e4SLinus Torvalds /* initialize free list */ 953a246b010SChuck Lever for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--) 9541da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 9551da177e4SLinus Torvalds 9561da177e4SLinus Torvalds xprt_init_xid(xprt); 9571da177e4SLinus Torvalds 9581da177e4SLinus Torvalds dprintk("RPC: created transport %p with %u slots\n", xprt, 9591da177e4SLinus Torvalds xprt->max_reqs); 9601da177e4SLinus Torvalds 9611da177e4SLinus Torvalds return xprt; 9621da177e4SLinus Torvalds } 9631da177e4SLinus Torvalds 9649903cd1cSChuck Lever /** 9659903cd1cSChuck Lever * xprt_create_proto - create an RPC client transport 9669903cd1cSChuck Lever * @proto: requested transport protocol 9679903cd1cSChuck Lever * @sap: remote peer's address 9689903cd1cSChuck Lever * @to: timeout parameters for new transport 9699903cd1cSChuck Lever * 9701da177e4SLinus Torvalds */ 9719903cd1cSChuck Lever struct rpc_xprt *xprt_create_proto(int proto, struct sockaddr_in *sap, struct rpc_timeout *to) 9721da177e4SLinus Torvalds { 9731da177e4SLinus Torvalds struct rpc_xprt *xprt; 9741da177e4SLinus Torvalds 9751da177e4SLinus Torvalds xprt = xprt_setup(proto, sap, to); 9761da177e4SLinus Torvalds if (IS_ERR(xprt)) 9771da177e4SLinus Torvalds dprintk("RPC: xprt_create_proto failed\n"); 9781da177e4SLinus Torvalds else 9791da177e4SLinus Torvalds dprintk("RPC: xprt_create_proto created xprt %p\n", xprt); 9801da177e4SLinus Torvalds return xprt; 9811da177e4SLinus Torvalds } 9821da177e4SLinus Torvalds 9839903cd1cSChuck Lever /** 9849903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 9859903cd1cSChuck Lever * @xprt: transport to destroy 9869903cd1cSChuck Lever * 9871da177e4SLinus Torvalds */ 9889903cd1cSChuck Lever int xprt_destroy(struct rpc_xprt *xprt) 9891da177e4SLinus Torvalds { 9901da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 9910065db32STrond Myklebust xprt->shutdown = 1; 9920065db32STrond Myklebust del_timer_sync(&xprt->timer); 993a246b010SChuck Lever xprt->ops->destroy(xprt); 9941da177e4SLinus Torvalds kfree(xprt); 9951da177e4SLinus Torvalds 9961da177e4SLinus Torvalds return 0; 9971da177e4SLinus Torvalds } 998