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> 44bf3fcf89SChuck Lever #include <linux/net.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 655ba03e82SJiri Slaby static DEFINE_SPINLOCK(xprt_list_lock); 6681c098afS\"Talpey, Thomas\ static LIST_HEAD(xprt_list); 6781c098afS\"Talpey, Thomas\ 68555ee3afSChuck Lever /* 69555ee3afSChuck Lever * The transport code maintains an estimate on the maximum number of out- 70555ee3afSChuck Lever * standing RPC requests, using a smoothed version of the congestion 71555ee3afSChuck Lever * avoidance implemented in 44BSD. This is basically the Van Jacobson 72555ee3afSChuck Lever * congestion algorithm: If a retransmit occurs, the congestion window is 73555ee3afSChuck Lever * halved; otherwise, it is incremented by 1/cwnd when 74555ee3afSChuck Lever * 75555ee3afSChuck Lever * - a reply is received and 76555ee3afSChuck Lever * - a full number of requests are outstanding and 77555ee3afSChuck Lever * - the congestion window hasn't been updated recently. 78555ee3afSChuck Lever */ 79555ee3afSChuck Lever #define RPC_CWNDSHIFT (8U) 80555ee3afSChuck Lever #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT) 81555ee3afSChuck Lever #define RPC_INITCWND RPC_CWNDSCALE 82555ee3afSChuck Lever #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT) 83555ee3afSChuck Lever 84555ee3afSChuck Lever #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) 851da177e4SLinus Torvalds 8612a80469SChuck Lever /** 8781c098afS\"Talpey, Thomas\ * xprt_register_transport - register a transport implementation 8881c098afS\"Talpey, Thomas\ * @transport: transport to register 8981c098afS\"Talpey, Thomas\ * 9081c098afS\"Talpey, Thomas\ * If a transport implementation is loaded as a kernel module, it can 9181c098afS\"Talpey, Thomas\ * call this interface to make itself known to the RPC client. 9281c098afS\"Talpey, Thomas\ * 9381c098afS\"Talpey, Thomas\ * Returns: 9481c098afS\"Talpey, Thomas\ * 0: transport successfully registered 9581c098afS\"Talpey, Thomas\ * -EEXIST: transport already registered 9681c098afS\"Talpey, Thomas\ * -EINVAL: transport module being unloaded 9781c098afS\"Talpey, Thomas\ */ 9881c098afS\"Talpey, Thomas\ int xprt_register_transport(struct xprt_class *transport) 9981c098afS\"Talpey, Thomas\ { 10081c098afS\"Talpey, Thomas\ struct xprt_class *t; 10181c098afS\"Talpey, Thomas\ int result; 10281c098afS\"Talpey, Thomas\ 10381c098afS\"Talpey, Thomas\ result = -EEXIST; 10481c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 10581c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 10681c098afS\"Talpey, Thomas\ /* don't register the same transport class twice */ 1074fa016ebS\"Talpey, Thomas\ if (t->ident == transport->ident) 10881c098afS\"Talpey, Thomas\ goto out; 10981c098afS\"Talpey, Thomas\ } 11081c098afS\"Talpey, Thomas\ 11181c098afS\"Talpey, Thomas\ result = -EINVAL; 11281c098afS\"Talpey, Thomas\ if (try_module_get(THIS_MODULE)) { 11381c098afS\"Talpey, Thomas\ list_add_tail(&transport->list, &xprt_list); 11481c098afS\"Talpey, Thomas\ printk(KERN_INFO "RPC: Registered %s transport module.\n", 11581c098afS\"Talpey, Thomas\ transport->name); 11681c098afS\"Talpey, Thomas\ result = 0; 11781c098afS\"Talpey, Thomas\ } 11881c098afS\"Talpey, Thomas\ 11981c098afS\"Talpey, Thomas\ out: 12081c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 12181c098afS\"Talpey, Thomas\ return result; 12281c098afS\"Talpey, Thomas\ } 12381c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_register_transport); 12481c098afS\"Talpey, Thomas\ 12581c098afS\"Talpey, Thomas\ /** 12681c098afS\"Talpey, Thomas\ * xprt_unregister_transport - unregister a transport implementation 12781c098afS\"Talpey, Thomas\ * transport: transport to unregister 12881c098afS\"Talpey, Thomas\ * 12981c098afS\"Talpey, Thomas\ * Returns: 13081c098afS\"Talpey, Thomas\ * 0: transport successfully unregistered 13181c098afS\"Talpey, Thomas\ * -ENOENT: transport never registered 13281c098afS\"Talpey, Thomas\ */ 13381c098afS\"Talpey, Thomas\ int xprt_unregister_transport(struct xprt_class *transport) 13481c098afS\"Talpey, Thomas\ { 13581c098afS\"Talpey, Thomas\ struct xprt_class *t; 13681c098afS\"Talpey, Thomas\ int result; 13781c098afS\"Talpey, Thomas\ 13881c098afS\"Talpey, Thomas\ result = 0; 13981c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 14081c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 14181c098afS\"Talpey, Thomas\ if (t == transport) { 14281c098afS\"Talpey, Thomas\ printk(KERN_INFO 14381c098afS\"Talpey, Thomas\ "RPC: Unregistered %s transport module.\n", 14481c098afS\"Talpey, Thomas\ transport->name); 14581c098afS\"Talpey, Thomas\ list_del_init(&transport->list); 14681c098afS\"Talpey, Thomas\ module_put(THIS_MODULE); 14781c098afS\"Talpey, Thomas\ goto out; 14881c098afS\"Talpey, Thomas\ } 14981c098afS\"Talpey, Thomas\ } 15081c098afS\"Talpey, Thomas\ result = -ENOENT; 15181c098afS\"Talpey, Thomas\ 15281c098afS\"Talpey, Thomas\ out: 15381c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 15481c098afS\"Talpey, Thomas\ return result; 15581c098afS\"Talpey, Thomas\ } 15681c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_unregister_transport); 15781c098afS\"Talpey, Thomas\ 15881c098afS\"Talpey, Thomas\ /** 15912a80469SChuck Lever * xprt_reserve_xprt - serialize write access to transports 16012a80469SChuck Lever * @task: task that is requesting access to the transport 16112a80469SChuck Lever * 16212a80469SChuck Lever * This prevents mixing the payload of separate requests, and prevents 16312a80469SChuck Lever * transport connects from colliding with writes. No congestion control 16412a80469SChuck Lever * is provided. 1651da177e4SLinus Torvalds */ 16612a80469SChuck Lever int xprt_reserve_xprt(struct rpc_task *task) 1671da177e4SLinus Torvalds { 16812a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 16912a80469SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 17012a80469SChuck Lever 17112a80469SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 17212a80469SChuck Lever if (task == xprt->snd_task) 17312a80469SChuck Lever return 1; 17412a80469SChuck Lever if (task == NULL) 17512a80469SChuck Lever return 0; 17612a80469SChuck Lever goto out_sleep; 17712a80469SChuck Lever } 17812a80469SChuck Lever xprt->snd_task = task; 17912a80469SChuck Lever if (req) { 18012a80469SChuck Lever req->rq_bytes_sent = 0; 18112a80469SChuck Lever req->rq_ntrans++; 18212a80469SChuck Lever } 18312a80469SChuck Lever return 1; 18412a80469SChuck Lever 18512a80469SChuck Lever out_sleep: 18646121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", 18712a80469SChuck Lever task->tk_pid, xprt); 18812a80469SChuck Lever task->tk_timeout = 0; 18912a80469SChuck Lever task->tk_status = -EAGAIN; 19012a80469SChuck Lever if (req && req->rq_ntrans) 19112a80469SChuck Lever rpc_sleep_on(&xprt->resend, task, NULL, NULL); 19212a80469SChuck Lever else 19312a80469SChuck Lever rpc_sleep_on(&xprt->sending, task, NULL, NULL); 19412a80469SChuck Lever return 0; 19512a80469SChuck Lever } 19612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt); 19712a80469SChuck Lever 198632e3bdcSTrond Myklebust static void xprt_clear_locked(struct rpc_xprt *xprt) 199632e3bdcSTrond Myklebust { 200632e3bdcSTrond Myklebust xprt->snd_task = NULL; 201632e3bdcSTrond Myklebust if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) { 202632e3bdcSTrond Myklebust smp_mb__before_clear_bit(); 203632e3bdcSTrond Myklebust clear_bit(XPRT_LOCKED, &xprt->state); 204632e3bdcSTrond Myklebust smp_mb__after_clear_bit(); 205632e3bdcSTrond Myklebust } else 206c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 207632e3bdcSTrond Myklebust } 208632e3bdcSTrond Myklebust 20912a80469SChuck Lever /* 21012a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 21112a80469SChuck Lever * @task: task that is requesting access to the transport 21212a80469SChuck Lever * 21312a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 21412a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 21512a80469SChuck Lever * woken up and given access to the transport. 21612a80469SChuck Lever */ 21712a80469SChuck Lever int xprt_reserve_xprt_cong(struct rpc_task *task) 21812a80469SChuck Lever { 21912a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 2201da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2211da177e4SLinus Torvalds 2222226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 2231da177e4SLinus Torvalds if (task == xprt->snd_task) 2241da177e4SLinus Torvalds return 1; 2251da177e4SLinus Torvalds goto out_sleep; 2261da177e4SLinus Torvalds } 22712a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 2281da177e4SLinus Torvalds xprt->snd_task = task; 2291da177e4SLinus Torvalds if (req) { 2301da177e4SLinus Torvalds req->rq_bytes_sent = 0; 2311da177e4SLinus Torvalds req->rq_ntrans++; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds return 1; 2341da177e4SLinus Torvalds } 235632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2361da177e4SLinus Torvalds out_sleep: 23746121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); 2381da177e4SLinus Torvalds task->tk_timeout = 0; 2391da177e4SLinus Torvalds task->tk_status = -EAGAIN; 2401da177e4SLinus Torvalds if (req && req->rq_ntrans) 2411da177e4SLinus Torvalds rpc_sleep_on(&xprt->resend, task, NULL, NULL); 2421da177e4SLinus Torvalds else 2431da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 2441da177e4SLinus Torvalds return 0; 2451da177e4SLinus Torvalds } 24612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); 2471da177e4SLinus Torvalds 24812a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 2491da177e4SLinus Torvalds { 2501da177e4SLinus Torvalds int retval; 2511da177e4SLinus Torvalds 2524a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 25312a80469SChuck Lever retval = xprt->ops->reserve_xprt(task); 2544a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2551da177e4SLinus Torvalds return retval; 2561da177e4SLinus Torvalds } 2571da177e4SLinus Torvalds 25812a80469SChuck Lever static void __xprt_lock_write_next(struct rpc_xprt *xprt) 2591da177e4SLinus Torvalds { 2601da177e4SLinus Torvalds struct rpc_task *task; 26149e9a890SChuck Lever struct rpc_rqst *req; 26249e9a890SChuck Lever 26349e9a890SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 26449e9a890SChuck Lever return; 26549e9a890SChuck Lever 26649e9a890SChuck Lever task = rpc_wake_up_next(&xprt->resend); 26749e9a890SChuck Lever if (!task) { 26849e9a890SChuck Lever task = rpc_wake_up_next(&xprt->sending); 26949e9a890SChuck Lever if (!task) 27049e9a890SChuck Lever goto out_unlock; 27149e9a890SChuck Lever } 27249e9a890SChuck Lever 27349e9a890SChuck Lever req = task->tk_rqstp; 27449e9a890SChuck Lever xprt->snd_task = task; 27549e9a890SChuck Lever if (req) { 27649e9a890SChuck Lever req->rq_bytes_sent = 0; 27749e9a890SChuck Lever req->rq_ntrans++; 27849e9a890SChuck Lever } 27949e9a890SChuck Lever return; 28049e9a890SChuck Lever 28149e9a890SChuck Lever out_unlock: 282632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 28349e9a890SChuck Lever } 28449e9a890SChuck Lever 28549e9a890SChuck Lever static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 28649e9a890SChuck Lever { 28749e9a890SChuck Lever struct rpc_task *task; 2881da177e4SLinus Torvalds 2892226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 2901da177e4SLinus Torvalds return; 29149e9a890SChuck Lever if (RPCXPRT_CONGESTED(xprt)) 2921da177e4SLinus Torvalds goto out_unlock; 2931da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->resend); 2941da177e4SLinus Torvalds if (!task) { 2951da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->sending); 2961da177e4SLinus Torvalds if (!task) 2971da177e4SLinus Torvalds goto out_unlock; 2981da177e4SLinus Torvalds } 29949e9a890SChuck Lever if (__xprt_get_cong(xprt, task)) { 3001da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 3011da177e4SLinus Torvalds xprt->snd_task = task; 3021da177e4SLinus Torvalds if (req) { 3031da177e4SLinus Torvalds req->rq_bytes_sent = 0; 3041da177e4SLinus Torvalds req->rq_ntrans++; 3051da177e4SLinus Torvalds } 3061da177e4SLinus Torvalds return; 3071da177e4SLinus Torvalds } 3081da177e4SLinus Torvalds out_unlock: 309632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3101da177e4SLinus Torvalds } 3111da177e4SLinus Torvalds 31249e9a890SChuck Lever /** 31349e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 31449e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 31549e9a890SChuck Lever * @task: task that is releasing access to the transport 31649e9a890SChuck Lever * 31749e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 3181da177e4SLinus Torvalds */ 31949e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 3201da177e4SLinus Torvalds { 3211da177e4SLinus Torvalds if (xprt->snd_task == task) { 322632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3231da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 3241da177e4SLinus Torvalds } 3251da177e4SLinus Torvalds } 32612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt); 3271da177e4SLinus Torvalds 32849e9a890SChuck Lever /** 32949e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 33049e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 33149e9a890SChuck Lever * @task: task that is releasing access to the transport 33249e9a890SChuck Lever * 33349e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 33449e9a890SChuck Lever * transport if the transport's congestion window allows it. 33549e9a890SChuck Lever */ 33649e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 33749e9a890SChuck Lever { 33849e9a890SChuck Lever if (xprt->snd_task == task) { 339632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 34049e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 34149e9a890SChuck Lever } 34249e9a890SChuck Lever } 34312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); 34449e9a890SChuck Lever 34549e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 3461da177e4SLinus Torvalds { 3474a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 34849e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 3494a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 3501da177e4SLinus Torvalds } 3511da177e4SLinus Torvalds 3521da177e4SLinus Torvalds /* 3531da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 3541da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 3551da177e4SLinus Torvalds */ 3561da177e4SLinus Torvalds static int 3571da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 3581da177e4SLinus Torvalds { 3591da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds if (req->rq_cong) 3621da177e4SLinus Torvalds return 1; 36346121cf7SChuck Lever dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", 3641da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 3651da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 3661da177e4SLinus Torvalds return 0; 3671da177e4SLinus Torvalds req->rq_cong = 1; 3681da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 3691da177e4SLinus Torvalds return 1; 3701da177e4SLinus Torvalds } 3711da177e4SLinus Torvalds 3721da177e4SLinus Torvalds /* 3731da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 3741da177e4SLinus Torvalds * that has been sleeping due to congestion 3751da177e4SLinus Torvalds */ 3761da177e4SLinus Torvalds static void 3771da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 3781da177e4SLinus Torvalds { 3791da177e4SLinus Torvalds if (!req->rq_cong) 3801da177e4SLinus Torvalds return; 3811da177e4SLinus Torvalds req->rq_cong = 0; 3821da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 38349e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3841da177e4SLinus Torvalds } 3851da177e4SLinus Torvalds 38646c0ee8bSChuck Lever /** 387a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 388a58dd398SChuck Lever * @task: RPC request that recently completed 389a58dd398SChuck Lever * 390a58dd398SChuck Lever * Useful for transports that require congestion control. 391a58dd398SChuck Lever */ 392a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 393a58dd398SChuck Lever { 394a58dd398SChuck Lever __xprt_put_cong(task->tk_xprt, task->tk_rqstp); 395a58dd398SChuck Lever } 39612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); 397a58dd398SChuck Lever 398a58dd398SChuck Lever /** 39946c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 40046c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 40146c0ee8bSChuck Lever * @result: result code of completed RPC request 40246c0ee8bSChuck Lever * 4031da177e4SLinus Torvalds * We use a time-smoothed congestion estimator to avoid heavy oscillation. 4041da177e4SLinus Torvalds */ 40546c0ee8bSChuck Lever void xprt_adjust_cwnd(struct rpc_task *task, int result) 4061da177e4SLinus Torvalds { 40746c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 40846c0ee8bSChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 40946c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 4121da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 4131da177e4SLinus Torvalds * the result gets rounded properly. */ 4141da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 4151da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 4161da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 41749e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4181da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 4191da177e4SLinus Torvalds cwnd >>= 1; 4201da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 4211da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 4221da177e4SLinus Torvalds } 4231da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 4241da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 4251da177e4SLinus Torvalds xprt->cwnd = cwnd; 42646c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 4271da177e4SLinus Torvalds } 42812444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); 4291da177e4SLinus Torvalds 43044fbac22SChuck Lever /** 43144fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 43244fbac22SChuck Lever * @xprt: transport with waiting tasks 43344fbac22SChuck Lever * @status: result code to plant in each task before waking it 43444fbac22SChuck Lever * 43544fbac22SChuck Lever */ 43644fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 43744fbac22SChuck Lever { 43844fbac22SChuck Lever if (status < 0) 43944fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 44044fbac22SChuck Lever else 44144fbac22SChuck Lever rpc_wake_up(&xprt->pending); 44244fbac22SChuck Lever } 44312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); 44444fbac22SChuck Lever 445c7b2cae8SChuck Lever /** 446c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 447c7b2cae8SChuck Lever * @task: task to be put to sleep 448c7b2cae8SChuck Lever * 449c7b2cae8SChuck Lever */ 450c7b2cae8SChuck Lever void xprt_wait_for_buffer_space(struct rpc_task *task) 451c7b2cae8SChuck Lever { 452c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 453c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 454c7b2cae8SChuck Lever 455c7b2cae8SChuck Lever task->tk_timeout = req->rq_timeout; 456c7b2cae8SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, NULL); 457c7b2cae8SChuck Lever } 45812444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); 459c7b2cae8SChuck Lever 460c7b2cae8SChuck Lever /** 461c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 462c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 463c7b2cae8SChuck Lever * 464c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 465c7b2cae8SChuck Lever */ 466c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 467c7b2cae8SChuck Lever { 468c7b2cae8SChuck Lever if (unlikely(xprt->shutdown)) 469c7b2cae8SChuck Lever return; 470c7b2cae8SChuck Lever 471c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 472c7b2cae8SChuck Lever if (xprt->snd_task) { 47346121cf7SChuck Lever dprintk("RPC: write space: waking waiting task on " 47446121cf7SChuck Lever "xprt %p\n", xprt); 475c7b2cae8SChuck Lever rpc_wake_up_task(xprt->snd_task); 476c7b2cae8SChuck Lever } 477c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 478c7b2cae8SChuck Lever } 47912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_write_space); 480c7b2cae8SChuck Lever 481fe3aca29SChuck Lever /** 482fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 483fe3aca29SChuck Lever * @task: task whose timeout is to be set 484fe3aca29SChuck Lever * 485fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 486fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 487fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 488fe3aca29SChuck Lever */ 489fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 490fe3aca29SChuck Lever { 491fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 492fe3aca29SChuck Lever } 49312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); 494fe3aca29SChuck Lever 495fe3aca29SChuck Lever /* 496fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 497fe3aca29SChuck Lever * @task: task whose timeout is to be set 498fe3aca29SChuck Lever * 499fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 500fe3aca29SChuck Lever */ 501fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 502fe3aca29SChuck Lever { 503fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 504fe3aca29SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 505fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 506fe3aca29SChuck Lever unsigned long max_timeout = req->rq_xprt->timeout.to_maxval; 507fe3aca29SChuck Lever 508fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 509fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 510fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 511fe3aca29SChuck Lever task->tk_timeout = max_timeout; 512fe3aca29SChuck Lever } 51312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); 514fe3aca29SChuck Lever 5151da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 5161da177e4SLinus Torvalds { 5171da177e4SLinus Torvalds struct rpc_timeout *to = &req->rq_xprt->timeout; 5181da177e4SLinus Torvalds 5191da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 5201da177e4SLinus Torvalds if (to->to_exponential) 5211da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 5221da177e4SLinus Torvalds else 5231da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 5241da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 5251da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 5261da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 5271da177e4SLinus Torvalds } 5281da177e4SLinus Torvalds 5299903cd1cSChuck Lever /** 5309903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 5319903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 5329903cd1cSChuck Lever * 5331da177e4SLinus Torvalds */ 5341da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 5351da177e4SLinus Torvalds { 5361da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 5371da177e4SLinus Torvalds struct rpc_timeout *to = &xprt->timeout; 5381da177e4SLinus Torvalds int status = 0; 5391da177e4SLinus Torvalds 5401da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 5411da177e4SLinus Torvalds if (to->to_exponential) 5421da177e4SLinus Torvalds req->rq_timeout <<= 1; 5431da177e4SLinus Torvalds else 5441da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 5451da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 5461da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 5471da177e4SLinus Torvalds req->rq_retries++; 5481da177e4SLinus Torvalds } else { 5491da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 5501da177e4SLinus Torvalds req->rq_retries = 0; 5511da177e4SLinus Torvalds xprt_reset_majortimeo(req); 5521da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 5534a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5541da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 5554a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5561da177e4SLinus Torvalds status = -ETIMEDOUT; 5571da177e4SLinus Torvalds } 5581da177e4SLinus Torvalds 5591da177e4SLinus Torvalds if (req->rq_timeout == 0) { 5601da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 5611da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 5621da177e4SLinus Torvalds } 5631da177e4SLinus Torvalds return status; 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 56665f27f38SDavid Howells static void xprt_autoclose(struct work_struct *work) 5671da177e4SLinus Torvalds { 56865f27f38SDavid Howells struct rpc_xprt *xprt = 56965f27f38SDavid Howells container_of(work, struct rpc_xprt, task_cleanup); 5701da177e4SLinus Torvalds 5711da177e4SLinus Torvalds xprt_disconnect(xprt); 572a246b010SChuck Lever xprt->ops->close(xprt); 57366af1e55STrond Myklebust clear_bit(XPRT_CLOSE_WAIT, &xprt->state); 5741da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 5751da177e4SLinus Torvalds } 5761da177e4SLinus Torvalds 5779903cd1cSChuck Lever /** 5789903cd1cSChuck Lever * xprt_disconnect - mark a transport as disconnected 5799903cd1cSChuck Lever * @xprt: transport to flag for disconnect 5809903cd1cSChuck Lever * 5811da177e4SLinus Torvalds */ 582a246b010SChuck Lever void xprt_disconnect(struct rpc_xprt *xprt) 5831da177e4SLinus Torvalds { 5841da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 5854a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5861da177e4SLinus Torvalds xprt_clear_connected(xprt); 58744fbac22SChuck Lever xprt_wake_pending_tasks(xprt, -ENOTCONN); 5884a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5891da177e4SLinus Torvalds } 59012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_disconnect); 5911da177e4SLinus Torvalds 59266af1e55STrond Myklebust /** 59366af1e55STrond Myklebust * xprt_force_disconnect - force a transport to disconnect 59466af1e55STrond Myklebust * @xprt: transport to disconnect 59566af1e55STrond Myklebust * 59666af1e55STrond Myklebust */ 59766af1e55STrond Myklebust void xprt_force_disconnect(struct rpc_xprt *xprt) 59866af1e55STrond Myklebust { 59966af1e55STrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 60066af1e55STrond Myklebust spin_lock_bh(&xprt->transport_lock); 60166af1e55STrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 60266af1e55STrond Myklebust /* Try to schedule an autoclose RPC call */ 60366af1e55STrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 60466af1e55STrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 60566af1e55STrond Myklebust else if (xprt->snd_task != NULL) 60666af1e55STrond Myklebust rpc_wake_up_task(xprt->snd_task); 60766af1e55STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 60866af1e55STrond Myklebust } 60966af1e55STrond Myklebust EXPORT_SYMBOL_GPL(xprt_force_disconnect); 61066af1e55STrond Myklebust 6111da177e4SLinus Torvalds static void 6121da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 6131da177e4SLinus Torvalds { 6141da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 6151da177e4SLinus Torvalds 6164a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 6171da177e4SLinus Torvalds if (!list_empty(&xprt->recv) || xprt->shutdown) 6181da177e4SLinus Torvalds goto out_abort; 6192226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 6201da177e4SLinus Torvalds goto out_abort; 6214a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6222226feb6SChuck Lever if (xprt_connecting(xprt)) 6231da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 6241da177e4SLinus Torvalds else 625c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6261da177e4SLinus Torvalds return; 6271da177e4SLinus Torvalds out_abort: 6284a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6291da177e4SLinus Torvalds } 6301da177e4SLinus Torvalds 6319903cd1cSChuck Lever /** 6329903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 6339903cd1cSChuck Lever * @task: RPC task that is requesting the connect 6341da177e4SLinus Torvalds * 6351da177e4SLinus Torvalds */ 6361da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 6371da177e4SLinus Torvalds { 6381da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 6391da177e4SLinus Torvalds 64046121cf7SChuck Lever dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, 6411da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 6421da177e4SLinus Torvalds 643ec739ef0SChuck Lever if (!xprt_bound(xprt)) { 6441da177e4SLinus Torvalds task->tk_status = -EIO; 6451da177e4SLinus Torvalds return; 6461da177e4SLinus Torvalds } 6471da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 6481da177e4SLinus Torvalds return; 6491da177e4SLinus Torvalds if (xprt_connected(xprt)) 650a246b010SChuck Lever xprt_release_write(xprt, task); 651a246b010SChuck Lever else { 6521da177e4SLinus Torvalds if (task->tk_rqstp) 6531da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 6541da177e4SLinus Torvalds 65503bf4b70SChuck Lever task->tk_timeout = xprt->connect_timeout; 6561da177e4SLinus Torvalds rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL); 657262ca07dSChuck Lever xprt->stat.connect_start = jiffies; 658a246b010SChuck Lever xprt->ops->connect(task); 6591da177e4SLinus Torvalds } 6601da177e4SLinus Torvalds return; 6611da177e4SLinus Torvalds } 6621da177e4SLinus Torvalds 6639903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 6641da177e4SLinus Torvalds { 6651da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds if (task->tk_status >= 0) { 668262ca07dSChuck Lever xprt->stat.connect_count++; 669262ca07dSChuck Lever xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; 67046121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection established\n", 6711da177e4SLinus Torvalds task->tk_pid); 6721da177e4SLinus Torvalds return; 6731da177e4SLinus Torvalds } 6741da177e4SLinus Torvalds 6751da177e4SLinus Torvalds switch (task->tk_status) { 6761da177e4SLinus Torvalds case -ECONNREFUSED: 6771da177e4SLinus Torvalds case -ECONNRESET: 67846121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: server %s refused " 67946121cf7SChuck Lever "connection\n", task->tk_pid, 68046121cf7SChuck Lever task->tk_client->cl_server); 68123475d66SChuck Lever break; 6821da177e4SLinus Torvalds case -ENOTCONN: 68346121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection broken\n", 68423475d66SChuck Lever task->tk_pid); 68523475d66SChuck Lever break; 6861da177e4SLinus Torvalds case -ETIMEDOUT: 68746121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connect attempt timed " 68846121cf7SChuck Lever "out\n", task->tk_pid); 6891da177e4SLinus Torvalds break; 6901da177e4SLinus Torvalds default: 69146121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: error %d connecting to " 69246121cf7SChuck Lever "server %s\n", task->tk_pid, -task->tk_status, 69346121cf7SChuck Lever task->tk_client->cl_server); 6941da177e4SLinus Torvalds xprt_release_write(xprt, task); 69523475d66SChuck Lever task->tk_status = -EIO; 69623475d66SChuck Lever } 6971da177e4SLinus Torvalds } 6981da177e4SLinus Torvalds 6999903cd1cSChuck Lever /** 7009903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 7019903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 7029903cd1cSChuck Lever * @xid: RPC XID of incoming reply 7039903cd1cSChuck Lever * 7041da177e4SLinus Torvalds */ 705d8ed029dSAlexey Dobriyan struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) 7061da177e4SLinus Torvalds { 7071da177e4SLinus Torvalds struct list_head *pos; 7081da177e4SLinus Torvalds 7091da177e4SLinus Torvalds list_for_each(pos, &xprt->recv) { 7101da177e4SLinus Torvalds struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list); 711262ca07dSChuck Lever if (entry->rq_xid == xid) 712262ca07dSChuck Lever return entry; 7131da177e4SLinus Torvalds } 71446121cf7SChuck Lever 71546121cf7SChuck Lever dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", 71646121cf7SChuck Lever ntohl(xid)); 717262ca07dSChuck Lever xprt->stat.bad_xids++; 718262ca07dSChuck Lever return NULL; 7191da177e4SLinus Torvalds } 72012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_lookup_rqst); 7211da177e4SLinus Torvalds 7229903cd1cSChuck Lever /** 7231570c1e4SChuck Lever * xprt_update_rtt - update an RPC client's RTT state after receiving a reply 7241570c1e4SChuck Lever * @task: RPC request that recently completed 7259903cd1cSChuck Lever * 7261da177e4SLinus Torvalds */ 7271570c1e4SChuck Lever void xprt_update_rtt(struct rpc_task *task) 7281da177e4SLinus Torvalds { 7291570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 7301570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 7311da177e4SLinus Torvalds unsigned timer = task->tk_msg.rpc_proc->p_timer; 7321570c1e4SChuck Lever 7331da177e4SLinus Torvalds if (timer) { 7341da177e4SLinus Torvalds if (req->rq_ntrans == 1) 7351570c1e4SChuck Lever rpc_update_rtt(rtt, timer, 7361da177e4SLinus Torvalds (long)jiffies - req->rq_xtime); 7371570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 7381da177e4SLinus Torvalds } 7391da177e4SLinus Torvalds } 74012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_update_rtt); 7411da177e4SLinus Torvalds 7421570c1e4SChuck Lever /** 7431570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 7441570c1e4SChuck Lever * @task: RPC request that recently completed 7451570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 7461570c1e4SChuck Lever * 7471570c1e4SChuck Lever * Caller holds transport lock. 7481570c1e4SChuck Lever */ 7491570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 7501570c1e4SChuck Lever { 7511570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 7521da177e4SLinus Torvalds 7531570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 7541570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 7551da177e4SLinus Torvalds 756262ca07dSChuck Lever task->tk_xprt->stat.recvs++; 757ef759a2eSChuck Lever task->tk_rtt = (long)jiffies - req->rq_xtime; 758ef759a2eSChuck Lever 7591da177e4SLinus Torvalds list_del_init(&req->rq_list); 76043ac3f29STrond Myklebust /* Ensure all writes are done before we update req->rq_received */ 76143ac3f29STrond Myklebust smp_wmb(); 7621da177e4SLinus Torvalds req->rq_received = req->rq_private_buf.len = copied; 7631da177e4SLinus Torvalds rpc_wake_up_task(task); 7641da177e4SLinus Torvalds } 76512444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_complete_rqst); 7661da177e4SLinus Torvalds 76746c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 7681da177e4SLinus Torvalds { 7691da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 7701da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 7711da177e4SLinus Torvalds 77246121cf7SChuck Lever dprintk("RPC: %5u xprt_timer\n", task->tk_pid); 77346c0ee8bSChuck Lever 7744a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 77546c0ee8bSChuck Lever if (!req->rq_received) { 77646c0ee8bSChuck Lever if (xprt->ops->timer) 77746c0ee8bSChuck Lever xprt->ops->timer(task); 7781da177e4SLinus Torvalds task->tk_status = -ETIMEDOUT; 77946c0ee8bSChuck Lever } 7801da177e4SLinus Torvalds task->tk_timeout = 0; 7811da177e4SLinus Torvalds rpc_wake_up_task(task); 7824a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 7831da177e4SLinus Torvalds } 7841da177e4SLinus Torvalds 7859903cd1cSChuck Lever /** 7869903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 7879903cd1cSChuck Lever * @task: RPC task about to send a request 7889903cd1cSChuck Lever * 7891da177e4SLinus Torvalds */ 7909903cd1cSChuck Lever int xprt_prepare_transmit(struct rpc_task *task) 7911da177e4SLinus Torvalds { 7921da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 7931da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 7941da177e4SLinus Torvalds int err = 0; 7951da177e4SLinus Torvalds 79646121cf7SChuck Lever dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); 7971da177e4SLinus Torvalds 7984a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 7991da177e4SLinus Torvalds if (req->rq_received && !req->rq_bytes_sent) { 8001da177e4SLinus Torvalds err = req->rq_received; 8011da177e4SLinus Torvalds goto out_unlock; 8021da177e4SLinus Torvalds } 80312a80469SChuck Lever if (!xprt->ops->reserve_xprt(task)) { 8041da177e4SLinus Torvalds err = -EAGAIN; 8051da177e4SLinus Torvalds goto out_unlock; 8061da177e4SLinus Torvalds } 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds if (!xprt_connected(xprt)) { 8091da177e4SLinus Torvalds err = -ENOTCONN; 8101da177e4SLinus Torvalds goto out_unlock; 8111da177e4SLinus Torvalds } 8121da177e4SLinus Torvalds out_unlock: 8134a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 8141da177e4SLinus Torvalds return err; 8151da177e4SLinus Torvalds } 8161da177e4SLinus Torvalds 817e0ab53deSTrond Myklebust void xprt_end_transmit(struct rpc_task *task) 8185e5ce5beSTrond Myklebust { 819e0ab53deSTrond Myklebust xprt_release_write(task->tk_xprt, task); 8205e5ce5beSTrond Myklebust } 8215e5ce5beSTrond Myklebust 8229903cd1cSChuck Lever /** 8239903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 8249903cd1cSChuck Lever * @task: controlling RPC task 8259903cd1cSChuck Lever * 8269903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 8279903cd1cSChuck Lever */ 8289903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 8291da177e4SLinus Torvalds { 8301da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8311da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 832a246b010SChuck Lever int status; 8331da177e4SLinus Torvalds 83446121cf7SChuck Lever dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 8351da177e4SLinus Torvalds 8361da177e4SLinus Torvalds if (!req->rq_received) { 8371da177e4SLinus Torvalds if (list_empty(&req->rq_list)) { 8384a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 8391da177e4SLinus Torvalds /* Update the softirq receive buffer */ 8401da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 8411da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 8421da177e4SLinus Torvalds /* Add request to the receive list */ 8431da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 8444a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 8451da177e4SLinus Torvalds xprt_reset_majortimeo(req); 8460f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 8470f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 8481da177e4SLinus Torvalds } 8491da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 8501da177e4SLinus Torvalds return; 8511da177e4SLinus Torvalds 852a246b010SChuck Lever status = xprt->ops->send_request(task); 853fe3aca29SChuck Lever if (status == 0) { 85446121cf7SChuck Lever dprintk("RPC: %5u xmit complete\n", task->tk_pid); 855fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 856262ca07dSChuck Lever 857fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 858262ca07dSChuck Lever 859262ca07dSChuck Lever xprt->stat.sends++; 860262ca07dSChuck Lever xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; 861262ca07dSChuck Lever xprt->stat.bklog_u += xprt->backlog.qlen; 862262ca07dSChuck Lever 863fe3aca29SChuck Lever /* Don't race with disconnect */ 864fe3aca29SChuck Lever if (!xprt_connected(xprt)) 865fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 866fe3aca29SChuck Lever else if (!req->rq_received) 867fe3aca29SChuck Lever rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer); 868fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 869fe3aca29SChuck Lever return; 870fe3aca29SChuck Lever } 8711da177e4SLinus Torvalds 8721da177e4SLinus Torvalds /* Note: at this point, task->tk_sleeping has not yet been set, 8731da177e4SLinus Torvalds * hence there is no danger of the waking up task being put on 8741da177e4SLinus Torvalds * schedq, and being picked up by a parallel run of rpciod(). 8751da177e4SLinus Torvalds */ 8761da177e4SLinus Torvalds task->tk_status = status; 877e0ab53deSTrond Myklebust if (status == -ECONNREFUSED) 8781da177e4SLinus Torvalds rpc_sleep_on(&xprt->sending, task, NULL, NULL); 8791da177e4SLinus Torvalds } 8801da177e4SLinus Torvalds 8819903cd1cSChuck Lever static inline void do_xprt_reserve(struct rpc_task *task) 8821da177e4SLinus Torvalds { 8831da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 8841da177e4SLinus Torvalds 8851da177e4SLinus Torvalds task->tk_status = 0; 8861da177e4SLinus Torvalds if (task->tk_rqstp) 8871da177e4SLinus Torvalds return; 8881da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 8891da177e4SLinus Torvalds struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 8901da177e4SLinus Torvalds list_del_init(&req->rq_list); 8911da177e4SLinus Torvalds task->tk_rqstp = req; 8921da177e4SLinus Torvalds xprt_request_init(task, xprt); 8931da177e4SLinus Torvalds return; 8941da177e4SLinus Torvalds } 8951da177e4SLinus Torvalds dprintk("RPC: waiting for request slot\n"); 8961da177e4SLinus Torvalds task->tk_status = -EAGAIN; 8971da177e4SLinus Torvalds task->tk_timeout = 0; 8981da177e4SLinus Torvalds rpc_sleep_on(&xprt->backlog, task, NULL, NULL); 8991da177e4SLinus Torvalds } 9001da177e4SLinus Torvalds 9019903cd1cSChuck Lever /** 9029903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 9039903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 9049903cd1cSChuck Lever * 9059903cd1cSChuck Lever * If no more slots are available, place the task on the transport's 9069903cd1cSChuck Lever * backlog queue. 9079903cd1cSChuck Lever */ 9089903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 9091da177e4SLinus Torvalds { 9101da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 9111da177e4SLinus Torvalds 9121da177e4SLinus Torvalds task->tk_status = -EIO; 9135dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 9141da177e4SLinus Torvalds do_xprt_reserve(task); 9155dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 9161da177e4SLinus Torvalds } 9171da177e4SLinus Torvalds 918d8ed029dSAlexey Dobriyan static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) 9191da177e4SLinus Torvalds { 9201da177e4SLinus Torvalds return xprt->xid++; 9211da177e4SLinus Torvalds } 9221da177e4SLinus Torvalds 9231da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 9241da177e4SLinus Torvalds { 925bf3fcf89SChuck Lever xprt->xid = net_random(); 9261da177e4SLinus Torvalds } 9271da177e4SLinus Torvalds 9289903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 9291da177e4SLinus Torvalds { 9301da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvalds req->rq_timeout = xprt->timeout.to_initval; 9331da177e4SLinus Torvalds req->rq_task = task; 9341da177e4SLinus Torvalds req->rq_xprt = xprt; 93502107148SChuck Lever req->rq_buffer = NULL; 9361da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 937ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf = NULL; 938da45828eSTrond Myklebust xprt_reset_majortimeo(req); 93946121cf7SChuck Lever dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, 9401da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 9411da177e4SLinus Torvalds } 9421da177e4SLinus Torvalds 9439903cd1cSChuck Lever /** 9449903cd1cSChuck Lever * xprt_release - release an RPC request slot 9459903cd1cSChuck Lever * @task: task which is finished with the slot 9469903cd1cSChuck Lever * 9471da177e4SLinus Torvalds */ 9489903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 9491da177e4SLinus Torvalds { 9501da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 9511da177e4SLinus Torvalds struct rpc_rqst *req; 9521da177e4SLinus Torvalds 9531da177e4SLinus Torvalds if (!(req = task->tk_rqstp)) 9541da177e4SLinus Torvalds return; 95511c556b3SChuck Lever rpc_count_iostats(task); 9564a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 95749e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 958a58dd398SChuck Lever if (xprt->ops->release_request) 959a58dd398SChuck Lever xprt->ops->release_request(task); 9601da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 9611da177e4SLinus Torvalds list_del(&req->rq_list); 9621da177e4SLinus Torvalds xprt->last_used = jiffies; 9630065db32STrond Myklebust if (list_empty(&xprt->recv)) 964a246b010SChuck Lever mod_timer(&xprt->timer, 96503bf4b70SChuck Lever xprt->last_used + xprt->idle_timeout); 9664a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 967c5a4dd8bSChuck Lever xprt->ops->buf_free(req->rq_buffer); 9681da177e4SLinus Torvalds task->tk_rqstp = NULL; 969ead5e1c2SJ. Bruce Fields if (req->rq_release_snd_buf) 970ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf(req); 9711da177e4SLinus Torvalds memset(req, 0, sizeof(*req)); /* mark unused */ 9721da177e4SLinus Torvalds 97346121cf7SChuck Lever dprintk("RPC: %5u release request %p\n", task->tk_pid, req); 9741da177e4SLinus Torvalds 9755dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 9761da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 977555ee3afSChuck Lever rpc_wake_up_next(&xprt->backlog); 9785dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 9791da177e4SLinus Torvalds } 9801da177e4SLinus Torvalds 9819903cd1cSChuck Lever /** 9829903cd1cSChuck Lever * xprt_set_timeout - set constant RPC timeout 9839903cd1cSChuck Lever * @to: RPC timeout parameters to set up 9849903cd1cSChuck Lever * @retr: number of retries 9859903cd1cSChuck Lever * @incr: amount of increase after each retry 9869903cd1cSChuck Lever * 9871da177e4SLinus Torvalds */ 9889903cd1cSChuck Lever void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr) 9891da177e4SLinus Torvalds { 9901da177e4SLinus Torvalds to->to_initval = 9911da177e4SLinus Torvalds to->to_increment = incr; 992eab5c084SChuck Lever to->to_maxval = to->to_initval + (incr * retr); 9931da177e4SLinus Torvalds to->to_retries = retr; 9941da177e4SLinus Torvalds to->to_exponential = 0; 9951da177e4SLinus Torvalds } 9961da177e4SLinus Torvalds 997c2866763SChuck Lever /** 998c2866763SChuck Lever * xprt_create_transport - create an RPC transport 99996802a09SFrank van Maarseveen * @args: rpc transport creation arguments 1000c2866763SChuck Lever * 1001c2866763SChuck Lever */ 10023c341b0bS\"Talpey, Thomas\ struct rpc_xprt *xprt_create_transport(struct xprt_create *args) 1003c2866763SChuck Lever { 1004c2866763SChuck Lever struct rpc_xprt *xprt; 1005c2866763SChuck Lever struct rpc_rqst *req; 1006bc25571eS\"Talpey, Thomas\ struct xprt_class *t; 1007c2866763SChuck Lever 1008bc25571eS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 1009bc25571eS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 10104fa016ebS\"Talpey, Thomas\ if (t->ident == args->ident) { 1011bc25571eS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 1012bc25571eS\"Talpey, Thomas\ goto found; 1013c2866763SChuck Lever } 1014bc25571eS\"Talpey, Thomas\ } 1015bc25571eS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 10164fa016ebS\"Talpey, Thomas\ printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); 1017bc25571eS\"Talpey, Thomas\ return ERR_PTR(-EIO); 1018bc25571eS\"Talpey, Thomas\ 1019bc25571eS\"Talpey, Thomas\ found: 1020bc25571eS\"Talpey, Thomas\ xprt = t->setup(args); 1021c8541ecdSChuck Lever if (IS_ERR(xprt)) { 1022c8541ecdSChuck Lever dprintk("RPC: xprt_create_transport: failed, %ld\n", 1023c8541ecdSChuck Lever -PTR_ERR(xprt)); 1024c8541ecdSChuck Lever return xprt; 1025c2866763SChuck Lever } 1026c2866763SChuck Lever 10276b6ca86bSTrond Myklebust kref_init(&xprt->kref); 1028c2866763SChuck Lever spin_lock_init(&xprt->transport_lock); 1029c2866763SChuck Lever spin_lock_init(&xprt->reserve_lock); 1030c2866763SChuck Lever 1031c2866763SChuck Lever INIT_LIST_HEAD(&xprt->free); 1032c2866763SChuck Lever INIT_LIST_HEAD(&xprt->recv); 103365f27f38SDavid Howells INIT_WORK(&xprt->task_cleanup, xprt_autoclose); 1034b24b8a24SPavel Emelyanov setup_timer(&xprt->timer, xprt_init_autodisconnect, 1035b24b8a24SPavel Emelyanov (unsigned long)xprt); 1036c2866763SChuck Lever xprt->last_used = jiffies; 1037c2866763SChuck Lever xprt->cwnd = RPC_INITCWND; 1038a509050bSChuck Lever xprt->bind_index = 0; 1039c2866763SChuck Lever 1040c2866763SChuck Lever rpc_init_wait_queue(&xprt->binding, "xprt_binding"); 1041c2866763SChuck Lever rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 1042c2866763SChuck Lever rpc_init_wait_queue(&xprt->sending, "xprt_sending"); 1043c2866763SChuck Lever rpc_init_wait_queue(&xprt->resend, "xprt_resend"); 1044c2866763SChuck Lever rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 1045c2866763SChuck Lever 1046c2866763SChuck Lever /* initialize free list */ 1047c2866763SChuck Lever for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--) 1048c2866763SChuck Lever list_add(&req->rq_list, &xprt->free); 1049c2866763SChuck Lever 1050c2866763SChuck Lever xprt_init_xid(xprt); 1051c2866763SChuck Lever 1052c2866763SChuck Lever dprintk("RPC: created transport %p with %u slots\n", xprt, 1053c2866763SChuck Lever xprt->max_reqs); 1054c2866763SChuck Lever 1055c2866763SChuck Lever return xprt; 1056c2866763SChuck Lever } 1057c2866763SChuck Lever 10589903cd1cSChuck Lever /** 10599903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 10606b6ca86bSTrond Myklebust * @kref: kref for the transport to destroy 10619903cd1cSChuck Lever * 10621da177e4SLinus Torvalds */ 10636b6ca86bSTrond Myklebust static void xprt_destroy(struct kref *kref) 10641da177e4SLinus Torvalds { 10656b6ca86bSTrond Myklebust struct rpc_xprt *xprt = container_of(kref, struct rpc_xprt, kref); 10666b6ca86bSTrond Myklebust 10671da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 10680065db32STrond Myklebust xprt->shutdown = 1; 10690065db32STrond Myklebust del_timer_sync(&xprt->timer); 1070c8541ecdSChuck Lever 1071c8541ecdSChuck Lever /* 1072c8541ecdSChuck Lever * Tear down transport state and free the rpc_xprt 1073c8541ecdSChuck Lever */ 1074a246b010SChuck Lever xprt->ops->destroy(xprt); 10756b6ca86bSTrond Myklebust } 10761da177e4SLinus Torvalds 10776b6ca86bSTrond Myklebust /** 10786b6ca86bSTrond Myklebust * xprt_put - release a reference to an RPC transport. 10796b6ca86bSTrond Myklebust * @xprt: pointer to the transport 10806b6ca86bSTrond Myklebust * 10816b6ca86bSTrond Myklebust */ 10826b6ca86bSTrond Myklebust void xprt_put(struct rpc_xprt *xprt) 10836b6ca86bSTrond Myklebust { 10846b6ca86bSTrond Myklebust kref_put(&xprt->kref, xprt_destroy); 10856b6ca86bSTrond Myklebust } 10866b6ca86bSTrond Myklebust 10876b6ca86bSTrond Myklebust /** 10886b6ca86bSTrond Myklebust * xprt_get - return a reference to an RPC transport. 10896b6ca86bSTrond Myklebust * @xprt: pointer to the transport 10906b6ca86bSTrond Myklebust * 10916b6ca86bSTrond Myklebust */ 10926b6ca86bSTrond Myklebust struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) 10936b6ca86bSTrond Myklebust { 10946b6ca86bSTrond Myklebust kref_get(&xprt->kref); 10956b6ca86bSTrond Myklebust return xprt; 10961da177e4SLinus Torvalds } 1097