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> 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds /* 491da177e4SLinus Torvalds * Local variables 501da177e4SLinus Torvalds */ 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds #ifdef RPC_DEBUG 531da177e4SLinus Torvalds # undef RPC_DEBUG_DATA 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 12212a80469SChuck Lever /* 12312a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 12412a80469SChuck Lever * @task: task that is requesting access to the transport 12512a80469SChuck Lever * 12612a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 12712a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 12812a80469SChuck Lever * woken up and given access to the transport. 12912a80469SChuck Lever */ 13012a80469SChuck Lever int xprt_reserve_xprt_cong(struct rpc_task *task) 13112a80469SChuck Lever { 13212a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 1331da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 1341da177e4SLinus Torvalds 1352226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 1361da177e4SLinus Torvalds if (task == xprt->snd_task) 1371da177e4SLinus Torvalds return 1; 1381da177e4SLinus Torvalds goto out_sleep; 1391da177e4SLinus Torvalds } 14012a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 1411da177e4SLinus Torvalds xprt->snd_task = task; 1421da177e4SLinus Torvalds if (req) { 1431da177e4SLinus Torvalds req->rq_bytes_sent = 0; 1441da177e4SLinus Torvalds req->rq_ntrans++; 1451da177e4SLinus Torvalds } 1461da177e4SLinus Torvalds return 1; 1471da177e4SLinus Torvalds } 1481da177e4SLinus Torvalds smp_mb__before_clear_bit(); 1492226feb6SChuck Lever clear_bit(XPRT_LOCKED, &xprt->state); 1501da177e4SLinus Torvalds smp_mb__after_clear_bit(); 1511da177e4SLinus Torvalds out_sleep: 15255aa4f58SChuck Lever dprintk("RPC: %4d failed to lock transport %p\n", task->tk_pid, xprt); 1531da177e4SLinus Torvalds task->tk_timeout = 0; 1541da177e4SLinus Torvalds task->tk_status = -EAGAIN; 1551da177e4SLinus Torvalds if (req && req->rq_ntrans) 1561da177e4SLinus Torvalds rpc_sleep_on(&xprt->resend, task, NULL, NULL); 1571da177e4SLinus Torvalds else 1581da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 1591da177e4SLinus Torvalds return 0; 1601da177e4SLinus Torvalds } 1611da177e4SLinus Torvalds 16212a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 1631da177e4SLinus Torvalds { 1641da177e4SLinus Torvalds int retval; 1651da177e4SLinus Torvalds 1664a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 16712a80469SChuck Lever retval = xprt->ops->reserve_xprt(task); 1684a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 1691da177e4SLinus Torvalds return retval; 1701da177e4SLinus Torvalds } 1711da177e4SLinus Torvalds 17212a80469SChuck Lever static void __xprt_lock_write_next(struct rpc_xprt *xprt) 1731da177e4SLinus Torvalds { 1741da177e4SLinus Torvalds struct rpc_task *task; 17549e9a890SChuck Lever struct rpc_rqst *req; 17649e9a890SChuck Lever 17749e9a890SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 17849e9a890SChuck Lever return; 17949e9a890SChuck Lever 18049e9a890SChuck Lever task = rpc_wake_up_next(&xprt->resend); 18149e9a890SChuck Lever if (!task) { 18249e9a890SChuck Lever task = rpc_wake_up_next(&xprt->sending); 18349e9a890SChuck Lever if (!task) 18449e9a890SChuck Lever goto out_unlock; 18549e9a890SChuck Lever } 18649e9a890SChuck Lever 18749e9a890SChuck Lever req = task->tk_rqstp; 18849e9a890SChuck Lever xprt->snd_task = task; 18949e9a890SChuck Lever if (req) { 19049e9a890SChuck Lever req->rq_bytes_sent = 0; 19149e9a890SChuck Lever req->rq_ntrans++; 19249e9a890SChuck Lever } 19349e9a890SChuck Lever return; 19449e9a890SChuck Lever 19549e9a890SChuck Lever out_unlock: 19649e9a890SChuck Lever smp_mb__before_clear_bit(); 19749e9a890SChuck Lever clear_bit(XPRT_LOCKED, &xprt->state); 19849e9a890SChuck Lever smp_mb__after_clear_bit(); 19949e9a890SChuck Lever } 20049e9a890SChuck Lever 20149e9a890SChuck Lever static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 20249e9a890SChuck Lever { 20349e9a890SChuck Lever struct rpc_task *task; 2041da177e4SLinus Torvalds 2052226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 2061da177e4SLinus Torvalds return; 20749e9a890SChuck Lever if (RPCXPRT_CONGESTED(xprt)) 2081da177e4SLinus Torvalds goto out_unlock; 2091da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->resend); 2101da177e4SLinus Torvalds if (!task) { 2111da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->sending); 2121da177e4SLinus Torvalds if (!task) 2131da177e4SLinus Torvalds goto out_unlock; 2141da177e4SLinus Torvalds } 21549e9a890SChuck Lever if (__xprt_get_cong(xprt, task)) { 2161da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2171da177e4SLinus Torvalds xprt->snd_task = task; 2181da177e4SLinus Torvalds if (req) { 2191da177e4SLinus Torvalds req->rq_bytes_sent = 0; 2201da177e4SLinus Torvalds req->rq_ntrans++; 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds return; 2231da177e4SLinus Torvalds } 2241da177e4SLinus Torvalds out_unlock: 2251da177e4SLinus Torvalds smp_mb__before_clear_bit(); 2262226feb6SChuck Lever clear_bit(XPRT_LOCKED, &xprt->state); 2271da177e4SLinus Torvalds smp_mb__after_clear_bit(); 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds 23049e9a890SChuck Lever /** 23149e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 23249e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 23349e9a890SChuck Lever * @task: task that is releasing access to the transport 23449e9a890SChuck Lever * 23549e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 2361da177e4SLinus Torvalds */ 23749e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 2381da177e4SLinus Torvalds { 2391da177e4SLinus Torvalds if (xprt->snd_task == task) { 2401da177e4SLinus Torvalds xprt->snd_task = NULL; 2411da177e4SLinus Torvalds smp_mb__before_clear_bit(); 2422226feb6SChuck Lever clear_bit(XPRT_LOCKED, &xprt->state); 2431da177e4SLinus Torvalds smp_mb__after_clear_bit(); 2441da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 2451da177e4SLinus Torvalds } 2461da177e4SLinus Torvalds } 2471da177e4SLinus Torvalds 24849e9a890SChuck Lever /** 24949e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 25049e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 25149e9a890SChuck Lever * @task: task that is releasing access to the transport 25249e9a890SChuck Lever * 25349e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 25449e9a890SChuck Lever * transport if the transport's congestion window allows it. 25549e9a890SChuck Lever */ 25649e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 25749e9a890SChuck Lever { 25849e9a890SChuck Lever if (xprt->snd_task == task) { 25949e9a890SChuck Lever xprt->snd_task = NULL; 26049e9a890SChuck Lever smp_mb__before_clear_bit(); 26149e9a890SChuck Lever clear_bit(XPRT_LOCKED, &xprt->state); 26249e9a890SChuck Lever smp_mb__after_clear_bit(); 26349e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 26449e9a890SChuck Lever } 26549e9a890SChuck Lever } 26649e9a890SChuck Lever 26749e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 2681da177e4SLinus Torvalds { 2694a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 27049e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 2714a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2721da177e4SLinus Torvalds } 2731da177e4SLinus Torvalds 2741da177e4SLinus Torvalds /* 2751da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 2761da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 2771da177e4SLinus Torvalds */ 2781da177e4SLinus Torvalds static int 2791da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 2801da177e4SLinus Torvalds { 2811da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2821da177e4SLinus Torvalds 2831da177e4SLinus Torvalds if (req->rq_cong) 2841da177e4SLinus Torvalds return 1; 2851da177e4SLinus Torvalds dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n", 2861da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 2871da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 2881da177e4SLinus Torvalds return 0; 2891da177e4SLinus Torvalds req->rq_cong = 1; 2901da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 2911da177e4SLinus Torvalds return 1; 2921da177e4SLinus Torvalds } 2931da177e4SLinus Torvalds 2941da177e4SLinus Torvalds /* 2951da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 2961da177e4SLinus Torvalds * that has been sleeping due to congestion 2971da177e4SLinus Torvalds */ 2981da177e4SLinus Torvalds static void 2991da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 3001da177e4SLinus Torvalds { 3011da177e4SLinus Torvalds if (!req->rq_cong) 3021da177e4SLinus Torvalds return; 3031da177e4SLinus Torvalds req->rq_cong = 0; 3041da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 30549e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3061da177e4SLinus Torvalds } 3071da177e4SLinus Torvalds 30846c0ee8bSChuck Lever /** 309a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 310a58dd398SChuck Lever * @task: RPC request that recently completed 311a58dd398SChuck Lever * 312a58dd398SChuck Lever * Useful for transports that require congestion control. 313a58dd398SChuck Lever */ 314a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 315a58dd398SChuck Lever { 316a58dd398SChuck Lever __xprt_put_cong(task->tk_xprt, task->tk_rqstp); 317a58dd398SChuck Lever } 318a58dd398SChuck Lever 319a58dd398SChuck Lever /** 32046c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 32146c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 32246c0ee8bSChuck Lever * @result: result code of completed RPC request 32346c0ee8bSChuck Lever * 3241da177e4SLinus Torvalds * We use a time-smoothed congestion estimator to avoid heavy oscillation. 3251da177e4SLinus Torvalds */ 32646c0ee8bSChuck Lever void xprt_adjust_cwnd(struct rpc_task *task, int result) 3271da177e4SLinus Torvalds { 32846c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 32946c0ee8bSChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 33046c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 3311da177e4SLinus Torvalds 3321da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 3331da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 3341da177e4SLinus Torvalds * the result gets rounded properly. */ 3351da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 3361da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 3371da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 33849e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3391da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 3401da177e4SLinus Torvalds cwnd >>= 1; 3411da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 3421da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 3431da177e4SLinus Torvalds } 3441da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 3451da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 3461da177e4SLinus Torvalds xprt->cwnd = cwnd; 34746c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 3481da177e4SLinus Torvalds } 3491da177e4SLinus Torvalds 35044fbac22SChuck Lever /** 35144fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 35244fbac22SChuck Lever * @xprt: transport with waiting tasks 35344fbac22SChuck Lever * @status: result code to plant in each task before waking it 35444fbac22SChuck Lever * 35544fbac22SChuck Lever */ 35644fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 35744fbac22SChuck Lever { 35844fbac22SChuck Lever if (status < 0) 35944fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 36044fbac22SChuck Lever else 36144fbac22SChuck Lever rpc_wake_up(&xprt->pending); 36244fbac22SChuck Lever } 36344fbac22SChuck Lever 364c7b2cae8SChuck Lever /** 365c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 366c7b2cae8SChuck Lever * @task: task to be put to sleep 367c7b2cae8SChuck Lever * 368c7b2cae8SChuck Lever */ 369c7b2cae8SChuck Lever void xprt_wait_for_buffer_space(struct rpc_task *task) 370c7b2cae8SChuck Lever { 371c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 372c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 373c7b2cae8SChuck Lever 374c7b2cae8SChuck Lever task->tk_timeout = req->rq_timeout; 375c7b2cae8SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, NULL); 376c7b2cae8SChuck Lever } 377c7b2cae8SChuck Lever 378c7b2cae8SChuck Lever /** 379c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 380c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 381c7b2cae8SChuck Lever * 382c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 383c7b2cae8SChuck Lever */ 384c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 385c7b2cae8SChuck Lever { 386c7b2cae8SChuck Lever if (unlikely(xprt->shutdown)) 387c7b2cae8SChuck Lever return; 388c7b2cae8SChuck Lever 389c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 390c7b2cae8SChuck Lever if (xprt->snd_task) { 391c7b2cae8SChuck Lever dprintk("RPC: write space: waking waiting task on xprt %p\n", 392c7b2cae8SChuck Lever xprt); 393c7b2cae8SChuck Lever rpc_wake_up_task(xprt->snd_task); 394c7b2cae8SChuck Lever } 395c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 396c7b2cae8SChuck Lever } 397c7b2cae8SChuck Lever 398fe3aca29SChuck Lever /** 399fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 400fe3aca29SChuck Lever * @task: task whose timeout is to be set 401fe3aca29SChuck Lever * 402fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 403fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 404fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 405fe3aca29SChuck Lever */ 406fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 407fe3aca29SChuck Lever { 408fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 409fe3aca29SChuck Lever } 410fe3aca29SChuck Lever 411fe3aca29SChuck Lever /* 412fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 413fe3aca29SChuck Lever * @task: task whose timeout is to be set 414fe3aca29SChuck Lever * 415fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 416fe3aca29SChuck Lever */ 417fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 418fe3aca29SChuck Lever { 419fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 420fe3aca29SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 421fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 422fe3aca29SChuck Lever unsigned long max_timeout = req->rq_xprt->timeout.to_maxval; 423fe3aca29SChuck Lever 424fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 425fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 426fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 427fe3aca29SChuck Lever task->tk_timeout = max_timeout; 428fe3aca29SChuck Lever } 429fe3aca29SChuck Lever 4301da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 4311da177e4SLinus Torvalds { 4321da177e4SLinus Torvalds struct rpc_timeout *to = &req->rq_xprt->timeout; 4331da177e4SLinus Torvalds 4341da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 4351da177e4SLinus Torvalds if (to->to_exponential) 4361da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 4371da177e4SLinus Torvalds else 4381da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 4391da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 4401da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 4411da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 4421da177e4SLinus Torvalds } 4431da177e4SLinus Torvalds 4449903cd1cSChuck Lever /** 4459903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 4469903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 4479903cd1cSChuck Lever * 4481da177e4SLinus Torvalds */ 4491da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 4501da177e4SLinus Torvalds { 4511da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 4521da177e4SLinus Torvalds struct rpc_timeout *to = &xprt->timeout; 4531da177e4SLinus Torvalds int status = 0; 4541da177e4SLinus Torvalds 4551da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 4561da177e4SLinus Torvalds if (to->to_exponential) 4571da177e4SLinus Torvalds req->rq_timeout <<= 1; 4581da177e4SLinus Torvalds else 4591da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 4601da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 4611da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 4621da177e4SLinus Torvalds req->rq_retries++; 4631da177e4SLinus Torvalds pprintk("RPC: %lu retrans\n", jiffies); 4641da177e4SLinus Torvalds } else { 4651da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 4661da177e4SLinus Torvalds req->rq_retries = 0; 4671da177e4SLinus Torvalds xprt_reset_majortimeo(req); 4681da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 4694a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 4701da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 4714a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 4721da177e4SLinus Torvalds pprintk("RPC: %lu timeout\n", jiffies); 4731da177e4SLinus Torvalds status = -ETIMEDOUT; 4741da177e4SLinus Torvalds } 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds if (req->rq_timeout == 0) { 4771da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 4781da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 4791da177e4SLinus Torvalds } 4801da177e4SLinus Torvalds return status; 4811da177e4SLinus Torvalds } 4821da177e4SLinus Torvalds 48355aa4f58SChuck Lever static void xprt_autoclose(void *args) 4841da177e4SLinus Torvalds { 4851da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)args; 4861da177e4SLinus Torvalds 4871da177e4SLinus Torvalds xprt_disconnect(xprt); 488a246b010SChuck Lever xprt->ops->close(xprt); 4891da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 4901da177e4SLinus Torvalds } 4911da177e4SLinus Torvalds 4929903cd1cSChuck Lever /** 4939903cd1cSChuck Lever * xprt_disconnect - mark a transport as disconnected 4949903cd1cSChuck Lever * @xprt: transport to flag for disconnect 4959903cd1cSChuck Lever * 4961da177e4SLinus Torvalds */ 497a246b010SChuck Lever void xprt_disconnect(struct rpc_xprt *xprt) 4981da177e4SLinus Torvalds { 4991da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 5004a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5011da177e4SLinus Torvalds xprt_clear_connected(xprt); 50244fbac22SChuck Lever xprt_wake_pending_tasks(xprt, -ENOTCONN); 5034a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5041da177e4SLinus Torvalds } 5051da177e4SLinus Torvalds 5061da177e4SLinus Torvalds static void 5071da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 5081da177e4SLinus Torvalds { 5091da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 5101da177e4SLinus Torvalds 5114a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 5121da177e4SLinus Torvalds if (!list_empty(&xprt->recv) || xprt->shutdown) 5131da177e4SLinus Torvalds goto out_abort; 5142226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 5151da177e4SLinus Torvalds goto out_abort; 5164a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 5172226feb6SChuck Lever if (xprt_connecting(xprt)) 5181da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 5191da177e4SLinus Torvalds else 5201da177e4SLinus Torvalds schedule_work(&xprt->task_cleanup); 5211da177e4SLinus Torvalds return; 5221da177e4SLinus Torvalds out_abort: 5234a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 5241da177e4SLinus Torvalds } 5251da177e4SLinus Torvalds 5269903cd1cSChuck Lever /** 5279903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 5289903cd1cSChuck Lever * @task: RPC task that is requesting the connect 5291da177e4SLinus Torvalds * 5301da177e4SLinus Torvalds */ 5311da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 5321da177e4SLinus Torvalds { 5331da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid, 5361da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvalds if (xprt->shutdown) { 5391da177e4SLinus Torvalds task->tk_status = -EIO; 5401da177e4SLinus Torvalds return; 5411da177e4SLinus Torvalds } 5421da177e4SLinus Torvalds if (!xprt->addr.sin_port) { 5431da177e4SLinus Torvalds task->tk_status = -EIO; 5441da177e4SLinus Torvalds return; 5451da177e4SLinus Torvalds } 5461da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 5471da177e4SLinus Torvalds return; 5481da177e4SLinus Torvalds if (xprt_connected(xprt)) 549a246b010SChuck Lever xprt_release_write(xprt, task); 550a246b010SChuck Lever else { 5511da177e4SLinus Torvalds if (task->tk_rqstp) 5521da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 5531da177e4SLinus Torvalds 55403bf4b70SChuck Lever task->tk_timeout = xprt->connect_timeout; 5551da177e4SLinus Torvalds rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL); 556a246b010SChuck Lever xprt->ops->connect(task); 5571da177e4SLinus Torvalds } 5581da177e4SLinus Torvalds return; 5591da177e4SLinus Torvalds } 5601da177e4SLinus Torvalds 5619903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 5621da177e4SLinus Torvalds { 5631da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 5641da177e4SLinus Torvalds 5651da177e4SLinus Torvalds if (task->tk_status >= 0) { 5661da177e4SLinus Torvalds dprintk("RPC: %4d xprt_connect_status: connection established\n", 5671da177e4SLinus Torvalds task->tk_pid); 5681da177e4SLinus Torvalds return; 5691da177e4SLinus Torvalds } 5701da177e4SLinus Torvalds 5711da177e4SLinus Torvalds switch (task->tk_status) { 5721da177e4SLinus Torvalds case -ECONNREFUSED: 5731da177e4SLinus Torvalds case -ECONNRESET: 57423475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: server %s refused connection\n", 57523475d66SChuck Lever task->tk_pid, task->tk_client->cl_server); 57623475d66SChuck Lever break; 5771da177e4SLinus Torvalds case -ENOTCONN: 57823475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: connection broken\n", 57923475d66SChuck Lever task->tk_pid); 58023475d66SChuck Lever break; 5811da177e4SLinus Torvalds case -ETIMEDOUT: 58223475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: connect attempt timed out\n", 5831da177e4SLinus Torvalds task->tk_pid); 5841da177e4SLinus Torvalds break; 5851da177e4SLinus Torvalds default: 58623475d66SChuck Lever dprintk("RPC: %4d xprt_connect_status: error %d connecting to server %s\n", 58723475d66SChuck Lever task->tk_pid, -task->tk_status, task->tk_client->cl_server); 5881da177e4SLinus Torvalds xprt_release_write(xprt, task); 58923475d66SChuck Lever task->tk_status = -EIO; 59023475d66SChuck Lever return; 59123475d66SChuck Lever } 59223475d66SChuck Lever 59323475d66SChuck Lever /* if soft mounted, just cause this RPC to fail */ 59423475d66SChuck Lever if (RPC_IS_SOFT(task)) { 59523475d66SChuck Lever xprt_release_write(xprt, task); 59623475d66SChuck Lever task->tk_status = -EIO; 59723475d66SChuck Lever } 5981da177e4SLinus Torvalds } 5991da177e4SLinus Torvalds 6009903cd1cSChuck Lever /** 6019903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 6029903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 6039903cd1cSChuck Lever * @xid: RPC XID of incoming reply 6049903cd1cSChuck Lever * 6051da177e4SLinus Torvalds */ 606a246b010SChuck Lever struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid) 6071da177e4SLinus Torvalds { 6081da177e4SLinus Torvalds struct list_head *pos; 6091da177e4SLinus Torvalds struct rpc_rqst *req = NULL; 6101da177e4SLinus Torvalds 6111da177e4SLinus Torvalds list_for_each(pos, &xprt->recv) { 6121da177e4SLinus Torvalds struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list); 6131da177e4SLinus Torvalds if (entry->rq_xid == xid) { 6141da177e4SLinus Torvalds req = entry; 6151da177e4SLinus Torvalds break; 6161da177e4SLinus Torvalds } 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds return req; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds 6219903cd1cSChuck Lever /** 6221570c1e4SChuck Lever * xprt_update_rtt - update an RPC client's RTT state after receiving a reply 6231570c1e4SChuck Lever * @task: RPC request that recently completed 6249903cd1cSChuck Lever * 6251da177e4SLinus Torvalds */ 6261570c1e4SChuck Lever void xprt_update_rtt(struct rpc_task *task) 6271da177e4SLinus Torvalds { 6281570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 6291570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 6301da177e4SLinus Torvalds unsigned timer = task->tk_msg.rpc_proc->p_timer; 6311570c1e4SChuck Lever 6321da177e4SLinus Torvalds if (timer) { 6331da177e4SLinus Torvalds if (req->rq_ntrans == 1) 6341570c1e4SChuck Lever rpc_update_rtt(rtt, timer, 6351da177e4SLinus Torvalds (long)jiffies - req->rq_xtime); 6361570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds } 6391da177e4SLinus Torvalds 6401570c1e4SChuck Lever /** 6411570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 6421570c1e4SChuck Lever * @task: RPC request that recently completed 6431570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 6441570c1e4SChuck Lever * 6451570c1e4SChuck Lever * Caller holds transport lock. 6461570c1e4SChuck Lever */ 6471570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 6481570c1e4SChuck Lever { 6491570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 6501da177e4SLinus Torvalds 6511570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 6521570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds list_del_init(&req->rq_list); 6551da177e4SLinus Torvalds req->rq_received = req->rq_private_buf.len = copied; 6561da177e4SLinus Torvalds rpc_wake_up_task(task); 6571da177e4SLinus Torvalds } 6581da177e4SLinus Torvalds 65946c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 6601da177e4SLinus Torvalds { 6611da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 6621da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 6631da177e4SLinus Torvalds 66446c0ee8bSChuck Lever dprintk("RPC: %4d xprt_timer\n", task->tk_pid); 66546c0ee8bSChuck Lever 6664a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 66746c0ee8bSChuck Lever if (!req->rq_received) { 66846c0ee8bSChuck Lever if (xprt->ops->timer) 66946c0ee8bSChuck Lever xprt->ops->timer(task); 6701da177e4SLinus Torvalds task->tk_status = -ETIMEDOUT; 67146c0ee8bSChuck Lever } 6721da177e4SLinus Torvalds task->tk_timeout = 0; 6731da177e4SLinus Torvalds rpc_wake_up_task(task); 6744a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6751da177e4SLinus Torvalds } 6761da177e4SLinus Torvalds 6779903cd1cSChuck Lever /** 6789903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 6799903cd1cSChuck Lever * @task: RPC task about to send a request 6809903cd1cSChuck Lever * 6811da177e4SLinus Torvalds */ 6829903cd1cSChuck Lever int xprt_prepare_transmit(struct rpc_task *task) 6831da177e4SLinus Torvalds { 6841da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 6851da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 6861da177e4SLinus Torvalds int err = 0; 6871da177e4SLinus Torvalds 6881da177e4SLinus Torvalds dprintk("RPC: %4d xprt_prepare_transmit\n", task->tk_pid); 6891da177e4SLinus Torvalds 6901da177e4SLinus Torvalds if (xprt->shutdown) 6911da177e4SLinus Torvalds return -EIO; 6921da177e4SLinus Torvalds 6934a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 6941da177e4SLinus Torvalds if (req->rq_received && !req->rq_bytes_sent) { 6951da177e4SLinus Torvalds err = req->rq_received; 6961da177e4SLinus Torvalds goto out_unlock; 6971da177e4SLinus Torvalds } 69812a80469SChuck Lever if (!xprt->ops->reserve_xprt(task)) { 6991da177e4SLinus Torvalds err = -EAGAIN; 7001da177e4SLinus Torvalds goto out_unlock; 7011da177e4SLinus Torvalds } 7021da177e4SLinus Torvalds 7031da177e4SLinus Torvalds if (!xprt_connected(xprt)) { 7041da177e4SLinus Torvalds err = -ENOTCONN; 7051da177e4SLinus Torvalds goto out_unlock; 7061da177e4SLinus Torvalds } 7071da177e4SLinus Torvalds out_unlock: 7084a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 7091da177e4SLinus Torvalds return err; 7101da177e4SLinus Torvalds } 7111da177e4SLinus Torvalds 7125e5ce5beSTrond Myklebust void 7135e5ce5beSTrond Myklebust xprt_abort_transmit(struct rpc_task *task) 7145e5ce5beSTrond Myklebust { 7155e5ce5beSTrond Myklebust struct rpc_xprt *xprt = task->tk_xprt; 7165e5ce5beSTrond Myklebust 7175e5ce5beSTrond Myklebust xprt_release_write(xprt, task); 7185e5ce5beSTrond Myklebust } 7195e5ce5beSTrond Myklebust 7209903cd1cSChuck Lever /** 7219903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 7229903cd1cSChuck Lever * @task: controlling RPC task 7239903cd1cSChuck Lever * 7249903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 7259903cd1cSChuck Lever */ 7269903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 7271da177e4SLinus Torvalds { 7281da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 7291da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 730a246b010SChuck Lever int status; 7311da177e4SLinus Torvalds 7321da177e4SLinus Torvalds dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 7331da177e4SLinus Torvalds 7341da177e4SLinus Torvalds smp_rmb(); 7351da177e4SLinus Torvalds if (!req->rq_received) { 7361da177e4SLinus Torvalds if (list_empty(&req->rq_list)) { 7374a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 7381da177e4SLinus Torvalds /* Update the softirq receive buffer */ 7391da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 7401da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 7411da177e4SLinus Torvalds /* Add request to the receive list */ 7421da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 7434a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 7441da177e4SLinus Torvalds xprt_reset_majortimeo(req); 7450f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 7460f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 7471da177e4SLinus Torvalds } 7481da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 7491da177e4SLinus Torvalds return; 7501da177e4SLinus Torvalds 751a246b010SChuck Lever status = xprt->ops->send_request(task); 752fe3aca29SChuck Lever if (status == 0) { 753fe3aca29SChuck Lever dprintk("RPC: %4d xmit complete\n", task->tk_pid); 754fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 755fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 756fe3aca29SChuck Lever /* Don't race with disconnect */ 757fe3aca29SChuck Lever if (!xprt_connected(xprt)) 758fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 759fe3aca29SChuck Lever else if (!req->rq_received) 760fe3aca29SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer); 76149e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 762fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 763fe3aca29SChuck Lever return; 764fe3aca29SChuck Lever } 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds /* Note: at this point, task->tk_sleeping has not yet been set, 7671da177e4SLinus Torvalds * hence there is no danger of the waking up task being put on 7681da177e4SLinus Torvalds * schedq, and being picked up by a parallel run of rpciod(). 7691da177e4SLinus Torvalds */ 7701da177e4SLinus Torvalds task->tk_status = status; 7711da177e4SLinus Torvalds 7721da177e4SLinus Torvalds switch (status) { 7731da177e4SLinus Torvalds case -ECONNREFUSED: 7741da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 775a246b010SChuck Lever case -EAGAIN: 7761da177e4SLinus Torvalds case -ENOTCONN: 7771da177e4SLinus Torvalds return; 7781da177e4SLinus Torvalds default: 77943118c29SChuck Lever break; 7801da177e4SLinus Torvalds } 7811da177e4SLinus Torvalds xprt_release_write(xprt, task); 7821da177e4SLinus Torvalds return; 7831da177e4SLinus Torvalds } 7841da177e4SLinus Torvalds 7859903cd1cSChuck Lever static inline void do_xprt_reserve(struct rpc_task *task) 7861da177e4SLinus Torvalds { 7871da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 7881da177e4SLinus Torvalds 7891da177e4SLinus Torvalds task->tk_status = 0; 7901da177e4SLinus Torvalds if (task->tk_rqstp) 7911da177e4SLinus Torvalds return; 7921da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 7931da177e4SLinus Torvalds struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 7941da177e4SLinus Torvalds list_del_init(&req->rq_list); 7951da177e4SLinus Torvalds task->tk_rqstp = req; 7961da177e4SLinus Torvalds xprt_request_init(task, xprt); 7971da177e4SLinus Torvalds return; 7981da177e4SLinus Torvalds } 7991da177e4SLinus Torvalds dprintk("RPC: waiting for request slot\n"); 8001da177e4SLinus Torvalds task->tk_status = -EAGAIN; 8011da177e4SLinus Torvalds task->tk_timeout = 0; 8021da177e4SLinus Torvalds rpc_sleep_on(&xprt->backlog, task, NULL, NULL); 8031da177e4SLinus Torvalds } 8041da177e4SLinus Torvalds 8059903cd1cSChuck Lever /** 8069903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 8079903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 8089903cd1cSChuck Lever * 8099903cd1cSChuck Lever * If no more slots are available, place the task on the transport's 8109903cd1cSChuck Lever * backlog queue. 8119903cd1cSChuck Lever */ 8129903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 8131da177e4SLinus Torvalds { 8141da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 8151da177e4SLinus Torvalds 8161da177e4SLinus Torvalds task->tk_status = -EIO; 8171da177e4SLinus Torvalds if (!xprt->shutdown) { 8185dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 8191da177e4SLinus Torvalds do_xprt_reserve(task); 8205dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 8211da177e4SLinus Torvalds } 8221da177e4SLinus Torvalds } 8231da177e4SLinus Torvalds 8241da177e4SLinus Torvalds static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt) 8251da177e4SLinus Torvalds { 8261da177e4SLinus Torvalds return xprt->xid++; 8271da177e4SLinus Torvalds } 8281da177e4SLinus Torvalds 8291da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 8301da177e4SLinus Torvalds { 8311da177e4SLinus Torvalds get_random_bytes(&xprt->xid, sizeof(xprt->xid)); 8321da177e4SLinus Torvalds } 8331da177e4SLinus Torvalds 8349903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 8351da177e4SLinus Torvalds { 8361da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8371da177e4SLinus Torvalds 8381da177e4SLinus Torvalds req->rq_timeout = xprt->timeout.to_initval; 8391da177e4SLinus Torvalds req->rq_task = task; 8401da177e4SLinus Torvalds req->rq_xprt = xprt; 8411da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 8421da177e4SLinus Torvalds dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid, 8431da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 8441da177e4SLinus Torvalds } 8451da177e4SLinus Torvalds 8469903cd1cSChuck Lever /** 8479903cd1cSChuck Lever * xprt_release - release an RPC request slot 8489903cd1cSChuck Lever * @task: task which is finished with the slot 8499903cd1cSChuck Lever * 8501da177e4SLinus Torvalds */ 8519903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 8521da177e4SLinus Torvalds { 8531da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 8541da177e4SLinus Torvalds struct rpc_rqst *req; 8551da177e4SLinus Torvalds 8561da177e4SLinus Torvalds if (!(req = task->tk_rqstp)) 8571da177e4SLinus Torvalds return; 8584a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 85949e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 860a58dd398SChuck Lever if (xprt->ops->release_request) 861a58dd398SChuck Lever xprt->ops->release_request(task); 8621da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 8631da177e4SLinus Torvalds list_del(&req->rq_list); 8641da177e4SLinus Torvalds xprt->last_used = jiffies; 8651da177e4SLinus Torvalds if (list_empty(&xprt->recv) && !xprt->shutdown) 866a246b010SChuck Lever mod_timer(&xprt->timer, 86703bf4b70SChuck Lever xprt->last_used + xprt->idle_timeout); 8684a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 8691da177e4SLinus Torvalds task->tk_rqstp = NULL; 8701da177e4SLinus Torvalds memset(req, 0, sizeof(*req)); /* mark unused */ 8711da177e4SLinus Torvalds 8721da177e4SLinus Torvalds dprintk("RPC: %4d release request %p\n", task->tk_pid, req); 8731da177e4SLinus Torvalds 8745dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 8751da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 876555ee3afSChuck Lever rpc_wake_up_next(&xprt->backlog); 8775dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 8781da177e4SLinus Torvalds } 8791da177e4SLinus Torvalds 8809903cd1cSChuck Lever /** 8819903cd1cSChuck Lever * xprt_set_timeout - set constant RPC timeout 8829903cd1cSChuck Lever * @to: RPC timeout parameters to set up 8839903cd1cSChuck Lever * @retr: number of retries 8849903cd1cSChuck Lever * @incr: amount of increase after each retry 8859903cd1cSChuck Lever * 8861da177e4SLinus Torvalds */ 8879903cd1cSChuck Lever void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr) 8881da177e4SLinus Torvalds { 8891da177e4SLinus Torvalds to->to_initval = 8901da177e4SLinus Torvalds to->to_increment = incr; 891eab5c084SChuck Lever to->to_maxval = to->to_initval + (incr * retr); 8921da177e4SLinus Torvalds to->to_retries = retr; 8931da177e4SLinus Torvalds to->to_exponential = 0; 8941da177e4SLinus Torvalds } 8951da177e4SLinus Torvalds 8969903cd1cSChuck Lever static struct rpc_xprt *xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to) 8971da177e4SLinus Torvalds { 898a246b010SChuck Lever int result; 8991da177e4SLinus Torvalds struct rpc_xprt *xprt; 9001da177e4SLinus Torvalds struct rpc_rqst *req; 9011da177e4SLinus Torvalds 9021da177e4SLinus Torvalds if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL) 9031da177e4SLinus Torvalds return ERR_PTR(-ENOMEM); 9041da177e4SLinus Torvalds memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */ 9051da177e4SLinus Torvalds 9061da177e4SLinus Torvalds xprt->addr = *ap; 907a246b010SChuck Lever 908a246b010SChuck Lever switch (proto) { 909a246b010SChuck Lever case IPPROTO_UDP: 910a246b010SChuck Lever result = xs_setup_udp(xprt, to); 911a246b010SChuck Lever break; 912a246b010SChuck Lever case IPPROTO_TCP: 913a246b010SChuck Lever result = xs_setup_tcp(xprt, to); 914a246b010SChuck Lever break; 915a246b010SChuck Lever default: 916a246b010SChuck Lever printk(KERN_ERR "RPC: unrecognized transport protocol: %d\n", 917a246b010SChuck Lever proto); 918a246b010SChuck Lever result = -EIO; 919a246b010SChuck Lever break; 9201da177e4SLinus Torvalds } 921a246b010SChuck Lever if (result) { 922a246b010SChuck Lever kfree(xprt); 923a246b010SChuck Lever return ERR_PTR(result); 924a246b010SChuck Lever } 925a246b010SChuck Lever 9264a0f8c04SChuck Lever spin_lock_init(&xprt->transport_lock); 9275dc07727SChuck Lever spin_lock_init(&xprt->reserve_lock); 9281da177e4SLinus Torvalds 9291da177e4SLinus Torvalds INIT_LIST_HEAD(&xprt->free); 9301da177e4SLinus Torvalds INIT_LIST_HEAD(&xprt->recv); 93155aa4f58SChuck Lever INIT_WORK(&xprt->task_cleanup, xprt_autoclose, xprt); 9321da177e4SLinus Torvalds init_timer(&xprt->timer); 9331da177e4SLinus Torvalds xprt->timer.function = xprt_init_autodisconnect; 9341da177e4SLinus Torvalds xprt->timer.data = (unsigned long) xprt; 9351da177e4SLinus Torvalds xprt->last_used = jiffies; 936555ee3afSChuck Lever xprt->cwnd = RPC_INITCWND; 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 9391da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->sending, "xprt_sending"); 9401da177e4SLinus Torvalds rpc_init_wait_queue(&xprt->resend, "xprt_resend"); 9411da177e4SLinus Torvalds rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds /* initialize free list */ 944a246b010SChuck Lever for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--) 9451da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 9461da177e4SLinus Torvalds 9471da177e4SLinus Torvalds xprt_init_xid(xprt); 9481da177e4SLinus Torvalds 9491da177e4SLinus Torvalds dprintk("RPC: created transport %p with %u slots\n", xprt, 9501da177e4SLinus Torvalds xprt->max_reqs); 9511da177e4SLinus Torvalds 9521da177e4SLinus Torvalds return xprt; 9531da177e4SLinus Torvalds } 9541da177e4SLinus Torvalds 9559903cd1cSChuck Lever /** 9569903cd1cSChuck Lever * xprt_create_proto - create an RPC client transport 9579903cd1cSChuck Lever * @proto: requested transport protocol 9589903cd1cSChuck Lever * @sap: remote peer's address 9599903cd1cSChuck Lever * @to: timeout parameters for new transport 9609903cd1cSChuck Lever * 9611da177e4SLinus Torvalds */ 9629903cd1cSChuck Lever struct rpc_xprt *xprt_create_proto(int proto, struct sockaddr_in *sap, struct rpc_timeout *to) 9631da177e4SLinus Torvalds { 9641da177e4SLinus Torvalds struct rpc_xprt *xprt; 9651da177e4SLinus Torvalds 9661da177e4SLinus Torvalds xprt = xprt_setup(proto, sap, to); 9671da177e4SLinus Torvalds if (IS_ERR(xprt)) 9681da177e4SLinus Torvalds dprintk("RPC: xprt_create_proto failed\n"); 9691da177e4SLinus Torvalds else 9701da177e4SLinus Torvalds dprintk("RPC: xprt_create_proto created xprt %p\n", xprt); 9711da177e4SLinus Torvalds return xprt; 9721da177e4SLinus Torvalds } 9731da177e4SLinus Torvalds 9749903cd1cSChuck Lever static void xprt_shutdown(struct rpc_xprt *xprt) 9751da177e4SLinus Torvalds { 9761da177e4SLinus Torvalds xprt->shutdown = 1; 9771da177e4SLinus Torvalds rpc_wake_up(&xprt->sending); 9781da177e4SLinus Torvalds rpc_wake_up(&xprt->resend); 97944fbac22SChuck Lever xprt_wake_pending_tasks(xprt, -EIO); 9801da177e4SLinus Torvalds rpc_wake_up(&xprt->backlog); 9811da177e4SLinus Torvalds del_timer_sync(&xprt->timer); 9821da177e4SLinus Torvalds } 9831da177e4SLinus Torvalds 9849903cd1cSChuck Lever /** 9859903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 9869903cd1cSChuck Lever * @xprt: transport to destroy 9879903cd1cSChuck Lever * 9881da177e4SLinus Torvalds */ 9899903cd1cSChuck Lever int xprt_destroy(struct rpc_xprt *xprt) 9901da177e4SLinus Torvalds { 9911da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 9921da177e4SLinus Torvalds xprt_shutdown(xprt); 993a246b010SChuck Lever xprt->ops->destroy(xprt); 9941da177e4SLinus Torvalds kfree(xprt); 9951da177e4SLinus Torvalds 9961da177e4SLinus Torvalds return 0; 9971da177e4SLinus Torvalds } 998