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\ list_add_tail(&transport->list, &xprt_list); 11281c098afS\"Talpey, Thomas\ printk(KERN_INFO "RPC: Registered %s transport module.\n", 11381c098afS\"Talpey, Thomas\ transport->name); 11481c098afS\"Talpey, Thomas\ result = 0; 11581c098afS\"Talpey, Thomas\ 11681c098afS\"Talpey, Thomas\ out: 11781c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 11881c098afS\"Talpey, Thomas\ return result; 11981c098afS\"Talpey, Thomas\ } 12081c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_register_transport); 12181c098afS\"Talpey, Thomas\ 12281c098afS\"Talpey, Thomas\ /** 12381c098afS\"Talpey, Thomas\ * xprt_unregister_transport - unregister a transport implementation 12465b6e42cSRandy Dunlap * @transport: transport to unregister 12581c098afS\"Talpey, Thomas\ * 12681c098afS\"Talpey, Thomas\ * Returns: 12781c098afS\"Talpey, Thomas\ * 0: transport successfully unregistered 12881c098afS\"Talpey, Thomas\ * -ENOENT: transport never registered 12981c098afS\"Talpey, Thomas\ */ 13081c098afS\"Talpey, Thomas\ int xprt_unregister_transport(struct xprt_class *transport) 13181c098afS\"Talpey, Thomas\ { 13281c098afS\"Talpey, Thomas\ struct xprt_class *t; 13381c098afS\"Talpey, Thomas\ int result; 13481c098afS\"Talpey, Thomas\ 13581c098afS\"Talpey, Thomas\ result = 0; 13681c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 13781c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 13881c098afS\"Talpey, Thomas\ if (t == transport) { 13981c098afS\"Talpey, Thomas\ printk(KERN_INFO 14081c098afS\"Talpey, Thomas\ "RPC: Unregistered %s transport module.\n", 14181c098afS\"Talpey, Thomas\ transport->name); 14281c098afS\"Talpey, Thomas\ list_del_init(&transport->list); 14381c098afS\"Talpey, Thomas\ goto out; 14481c098afS\"Talpey, Thomas\ } 14581c098afS\"Talpey, Thomas\ } 14681c098afS\"Talpey, Thomas\ result = -ENOENT; 14781c098afS\"Talpey, Thomas\ 14881c098afS\"Talpey, Thomas\ out: 14981c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 15081c098afS\"Talpey, Thomas\ return result; 15181c098afS\"Talpey, Thomas\ } 15281c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_unregister_transport); 15381c098afS\"Talpey, Thomas\ 15481c098afS\"Talpey, Thomas\ /** 15512a80469SChuck Lever * xprt_reserve_xprt - serialize write access to transports 15612a80469SChuck Lever * @task: task that is requesting access to the transport 15712a80469SChuck Lever * 15812a80469SChuck Lever * This prevents mixing the payload of separate requests, and prevents 15912a80469SChuck Lever * transport connects from colliding with writes. No congestion control 16012a80469SChuck Lever * is provided. 1611da177e4SLinus Torvalds */ 16212a80469SChuck Lever int xprt_reserve_xprt(struct rpc_task *task) 1631da177e4SLinus Torvalds { 16412a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 16512a80469SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 16612a80469SChuck Lever 16712a80469SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 16812a80469SChuck Lever if (task == xprt->snd_task) 16912a80469SChuck Lever return 1; 17012a80469SChuck Lever if (task == NULL) 17112a80469SChuck Lever return 0; 17212a80469SChuck Lever goto out_sleep; 17312a80469SChuck Lever } 17412a80469SChuck Lever xprt->snd_task = task; 17512a80469SChuck Lever if (req) { 17612a80469SChuck Lever req->rq_bytes_sent = 0; 17712a80469SChuck Lever req->rq_ntrans++; 17812a80469SChuck Lever } 17912a80469SChuck Lever return 1; 18012a80469SChuck Lever 18112a80469SChuck Lever out_sleep: 18246121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", 18312a80469SChuck Lever task->tk_pid, xprt); 18412a80469SChuck Lever task->tk_timeout = 0; 18512a80469SChuck Lever task->tk_status = -EAGAIN; 18612a80469SChuck Lever if (req && req->rq_ntrans) 1875d00837bSTrond Myklebust rpc_sleep_on(&xprt->resend, task, NULL); 18812a80469SChuck Lever else 1895d00837bSTrond Myklebust rpc_sleep_on(&xprt->sending, task, NULL); 19012a80469SChuck Lever return 0; 19112a80469SChuck Lever } 19212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt); 19312a80469SChuck Lever 194632e3bdcSTrond Myklebust static void xprt_clear_locked(struct rpc_xprt *xprt) 195632e3bdcSTrond Myklebust { 196632e3bdcSTrond Myklebust xprt->snd_task = NULL; 197632e3bdcSTrond Myklebust if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) { 198632e3bdcSTrond Myklebust smp_mb__before_clear_bit(); 199632e3bdcSTrond Myklebust clear_bit(XPRT_LOCKED, &xprt->state); 200632e3bdcSTrond Myklebust smp_mb__after_clear_bit(); 201632e3bdcSTrond Myklebust } else 202c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 203632e3bdcSTrond Myklebust } 204632e3bdcSTrond Myklebust 20512a80469SChuck Lever /* 20612a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 20712a80469SChuck Lever * @task: task that is requesting access to the transport 20812a80469SChuck Lever * 20912a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 21012a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 21112a80469SChuck Lever * woken up and given access to the transport. 21212a80469SChuck Lever */ 21312a80469SChuck Lever int xprt_reserve_xprt_cong(struct rpc_task *task) 21412a80469SChuck Lever { 21512a80469SChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 2161da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2171da177e4SLinus Torvalds 2182226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 2191da177e4SLinus Torvalds if (task == xprt->snd_task) 2201da177e4SLinus Torvalds return 1; 2211da177e4SLinus Torvalds goto out_sleep; 2221da177e4SLinus Torvalds } 22312a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 2241da177e4SLinus Torvalds xprt->snd_task = task; 2251da177e4SLinus Torvalds if (req) { 2261da177e4SLinus Torvalds req->rq_bytes_sent = 0; 2271da177e4SLinus Torvalds req->rq_ntrans++; 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds return 1; 2301da177e4SLinus Torvalds } 231632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2321da177e4SLinus Torvalds out_sleep: 23346121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); 2341da177e4SLinus Torvalds task->tk_timeout = 0; 2351da177e4SLinus Torvalds task->tk_status = -EAGAIN; 2361da177e4SLinus Torvalds if (req && req->rq_ntrans) 2375d00837bSTrond Myklebust rpc_sleep_on(&xprt->resend, task, NULL); 2381da177e4SLinus Torvalds else 2395d00837bSTrond Myklebust rpc_sleep_on(&xprt->sending, task, NULL); 2401da177e4SLinus Torvalds return 0; 2411da177e4SLinus Torvalds } 24212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); 2431da177e4SLinus Torvalds 24412a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 2451da177e4SLinus Torvalds { 2461da177e4SLinus Torvalds int retval; 2471da177e4SLinus Torvalds 2484a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 24912a80469SChuck Lever retval = xprt->ops->reserve_xprt(task); 2504a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2511da177e4SLinus Torvalds return retval; 2521da177e4SLinus Torvalds } 2531da177e4SLinus Torvalds 25412a80469SChuck Lever static void __xprt_lock_write_next(struct rpc_xprt *xprt) 2551da177e4SLinus Torvalds { 2561da177e4SLinus Torvalds struct rpc_task *task; 25749e9a890SChuck Lever struct rpc_rqst *req; 25849e9a890SChuck Lever 25949e9a890SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 26049e9a890SChuck Lever return; 26149e9a890SChuck Lever 26249e9a890SChuck Lever task = rpc_wake_up_next(&xprt->resend); 26349e9a890SChuck Lever if (!task) { 26449e9a890SChuck Lever task = rpc_wake_up_next(&xprt->sending); 26549e9a890SChuck Lever if (!task) 26649e9a890SChuck Lever goto out_unlock; 26749e9a890SChuck Lever } 26849e9a890SChuck Lever 26949e9a890SChuck Lever req = task->tk_rqstp; 27049e9a890SChuck Lever xprt->snd_task = task; 27149e9a890SChuck Lever if (req) { 27249e9a890SChuck Lever req->rq_bytes_sent = 0; 27349e9a890SChuck Lever req->rq_ntrans++; 27449e9a890SChuck Lever } 27549e9a890SChuck Lever return; 27649e9a890SChuck Lever 27749e9a890SChuck Lever out_unlock: 278632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 27949e9a890SChuck Lever } 28049e9a890SChuck Lever 28149e9a890SChuck Lever static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 28249e9a890SChuck Lever { 28349e9a890SChuck Lever struct rpc_task *task; 2841da177e4SLinus Torvalds 2852226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 2861da177e4SLinus Torvalds return; 28749e9a890SChuck Lever if (RPCXPRT_CONGESTED(xprt)) 2881da177e4SLinus Torvalds goto out_unlock; 2891da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->resend); 2901da177e4SLinus Torvalds if (!task) { 2911da177e4SLinus Torvalds task = rpc_wake_up_next(&xprt->sending); 2921da177e4SLinus Torvalds if (!task) 2931da177e4SLinus Torvalds goto out_unlock; 2941da177e4SLinus Torvalds } 29549e9a890SChuck Lever if (__xprt_get_cong(xprt, task)) { 2961da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 2971da177e4SLinus Torvalds xprt->snd_task = task; 2981da177e4SLinus Torvalds if (req) { 2991da177e4SLinus Torvalds req->rq_bytes_sent = 0; 3001da177e4SLinus Torvalds req->rq_ntrans++; 3011da177e4SLinus Torvalds } 3021da177e4SLinus Torvalds return; 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds out_unlock: 305632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3061da177e4SLinus Torvalds } 3071da177e4SLinus Torvalds 30849e9a890SChuck Lever /** 30949e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 31049e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 31149e9a890SChuck Lever * @task: task that is releasing access to the transport 31249e9a890SChuck Lever * 31349e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 3141da177e4SLinus Torvalds */ 31549e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 3161da177e4SLinus Torvalds { 3171da177e4SLinus Torvalds if (xprt->snd_task == task) { 318632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3191da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 3201da177e4SLinus Torvalds } 3211da177e4SLinus Torvalds } 32212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt); 3231da177e4SLinus Torvalds 32449e9a890SChuck Lever /** 32549e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 32649e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 32749e9a890SChuck Lever * @task: task that is releasing access to the transport 32849e9a890SChuck Lever * 32949e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 33049e9a890SChuck Lever * transport if the transport's congestion window allows it. 33149e9a890SChuck Lever */ 33249e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 33349e9a890SChuck Lever { 33449e9a890SChuck Lever if (xprt->snd_task == task) { 335632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 33649e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 33749e9a890SChuck Lever } 33849e9a890SChuck Lever } 33912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); 34049e9a890SChuck Lever 34149e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 3421da177e4SLinus Torvalds { 3434a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 34449e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 3454a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 3461da177e4SLinus Torvalds } 3471da177e4SLinus Torvalds 3481da177e4SLinus Torvalds /* 3491da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 3501da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 3511da177e4SLinus Torvalds */ 3521da177e4SLinus Torvalds static int 3531da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 3541da177e4SLinus Torvalds { 3551da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 3561da177e4SLinus Torvalds 3571da177e4SLinus Torvalds if (req->rq_cong) 3581da177e4SLinus Torvalds return 1; 35946121cf7SChuck Lever dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", 3601da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 3611da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 3621da177e4SLinus Torvalds return 0; 3631da177e4SLinus Torvalds req->rq_cong = 1; 3641da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 3651da177e4SLinus Torvalds return 1; 3661da177e4SLinus Torvalds } 3671da177e4SLinus Torvalds 3681da177e4SLinus Torvalds /* 3691da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 3701da177e4SLinus Torvalds * that has been sleeping due to congestion 3711da177e4SLinus Torvalds */ 3721da177e4SLinus Torvalds static void 3731da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 3741da177e4SLinus Torvalds { 3751da177e4SLinus Torvalds if (!req->rq_cong) 3761da177e4SLinus Torvalds return; 3771da177e4SLinus Torvalds req->rq_cong = 0; 3781da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 37949e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 3801da177e4SLinus Torvalds } 3811da177e4SLinus Torvalds 38246c0ee8bSChuck Lever /** 383a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 384a58dd398SChuck Lever * @task: RPC request that recently completed 385a58dd398SChuck Lever * 386a58dd398SChuck Lever * Useful for transports that require congestion control. 387a58dd398SChuck Lever */ 388a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 389a58dd398SChuck Lever { 390a58dd398SChuck Lever __xprt_put_cong(task->tk_xprt, task->tk_rqstp); 391a58dd398SChuck Lever } 39212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); 393a58dd398SChuck Lever 394a58dd398SChuck Lever /** 39546c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 39646c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 39746c0ee8bSChuck Lever * @result: result code of completed RPC request 39846c0ee8bSChuck Lever * 3991da177e4SLinus Torvalds * We use a time-smoothed congestion estimator to avoid heavy oscillation. 4001da177e4SLinus Torvalds */ 40146c0ee8bSChuck Lever void xprt_adjust_cwnd(struct rpc_task *task, int result) 4021da177e4SLinus Torvalds { 40346c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 40446c0ee8bSChuck Lever struct rpc_xprt *xprt = task->tk_xprt; 40546c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 4081da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 4091da177e4SLinus Torvalds * the result gets rounded properly. */ 4101da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 4111da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 4121da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 41349e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4141da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 4151da177e4SLinus Torvalds cwnd >>= 1; 4161da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 4171da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 4181da177e4SLinus Torvalds } 4191da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 4201da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 4211da177e4SLinus Torvalds xprt->cwnd = cwnd; 42246c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 4231da177e4SLinus Torvalds } 42412444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); 4251da177e4SLinus Torvalds 42644fbac22SChuck Lever /** 42744fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 42844fbac22SChuck Lever * @xprt: transport with waiting tasks 42944fbac22SChuck Lever * @status: result code to plant in each task before waking it 43044fbac22SChuck Lever * 43144fbac22SChuck Lever */ 43244fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 43344fbac22SChuck Lever { 43444fbac22SChuck Lever if (status < 0) 43544fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 43644fbac22SChuck Lever else 43744fbac22SChuck Lever rpc_wake_up(&xprt->pending); 43844fbac22SChuck Lever } 43912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); 44044fbac22SChuck Lever 441c7b2cae8SChuck Lever /** 442c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 443c7b2cae8SChuck Lever * @task: task to be put to sleep 4440b80ae42SRandy Dunlap * @action: function pointer to be executed after wait 445c7b2cae8SChuck Lever */ 446b6ddf64fSTrond Myklebust void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) 447c7b2cae8SChuck Lever { 448c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 449c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 450c7b2cae8SChuck Lever 451c7b2cae8SChuck Lever task->tk_timeout = req->rq_timeout; 452b6ddf64fSTrond Myklebust rpc_sleep_on(&xprt->pending, task, action); 453c7b2cae8SChuck Lever } 45412444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); 455c7b2cae8SChuck Lever 456c7b2cae8SChuck Lever /** 457c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 458c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 459c7b2cae8SChuck Lever * 460c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 461c7b2cae8SChuck Lever */ 462c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 463c7b2cae8SChuck Lever { 464c7b2cae8SChuck Lever if (unlikely(xprt->shutdown)) 465c7b2cae8SChuck Lever return; 466c7b2cae8SChuck Lever 467c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 468c7b2cae8SChuck Lever if (xprt->snd_task) { 46946121cf7SChuck Lever dprintk("RPC: write space: waking waiting task on " 47046121cf7SChuck Lever "xprt %p\n", xprt); 471fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); 472c7b2cae8SChuck Lever } 473c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 474c7b2cae8SChuck Lever } 47512444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_write_space); 476c7b2cae8SChuck Lever 477fe3aca29SChuck Lever /** 478fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 479fe3aca29SChuck Lever * @task: task whose timeout is to be set 480fe3aca29SChuck Lever * 481fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 482fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 483fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 484fe3aca29SChuck Lever */ 485fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 486fe3aca29SChuck Lever { 487fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 488fe3aca29SChuck Lever } 48912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); 490fe3aca29SChuck Lever 491fe3aca29SChuck Lever /* 492fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 493fe3aca29SChuck Lever * @task: task whose timeout is to be set 494fe3aca29SChuck Lever * 495fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 496fe3aca29SChuck Lever */ 497fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 498fe3aca29SChuck Lever { 499fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 500ba7392bbSTrond Myklebust struct rpc_clnt *clnt = task->tk_client; 501ba7392bbSTrond Myklebust struct rpc_rtt *rtt = clnt->cl_rtt; 502fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 503ba7392bbSTrond Myklebust unsigned long max_timeout = clnt->cl_timeout->to_maxval; 504fe3aca29SChuck Lever 505fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 506fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 507fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 508fe3aca29SChuck Lever task->tk_timeout = max_timeout; 509fe3aca29SChuck Lever } 51012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); 511fe3aca29SChuck Lever 5121da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 5131da177e4SLinus Torvalds { 514ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 5171da177e4SLinus Torvalds if (to->to_exponential) 5181da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 5191da177e4SLinus Torvalds else 5201da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 5211da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 5221da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 5231da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 5241da177e4SLinus Torvalds } 5251da177e4SLinus Torvalds 5269903cd1cSChuck Lever /** 5279903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 5289903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 5299903cd1cSChuck Lever * 5301da177e4SLinus Torvalds */ 5311da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 5321da177e4SLinus Torvalds { 5331da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 534ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5351da177e4SLinus Torvalds int status = 0; 5361da177e4SLinus Torvalds 5371da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 5381da177e4SLinus Torvalds if (to->to_exponential) 5391da177e4SLinus Torvalds req->rq_timeout <<= 1; 5401da177e4SLinus Torvalds else 5411da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 5421da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 5431da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 5441da177e4SLinus Torvalds req->rq_retries++; 5451da177e4SLinus Torvalds } else { 5461da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 5471da177e4SLinus Torvalds req->rq_retries = 0; 5481da177e4SLinus Torvalds xprt_reset_majortimeo(req); 5491da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 5504a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5511da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 5524a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5531da177e4SLinus Torvalds status = -ETIMEDOUT; 5541da177e4SLinus Torvalds } 5551da177e4SLinus Torvalds 5561da177e4SLinus Torvalds if (req->rq_timeout == 0) { 5571da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 5581da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 5591da177e4SLinus Torvalds } 5601da177e4SLinus Torvalds return status; 5611da177e4SLinus Torvalds } 5621da177e4SLinus Torvalds 56365f27f38SDavid Howells static void xprt_autoclose(struct work_struct *work) 5641da177e4SLinus Torvalds { 56565f27f38SDavid Howells struct rpc_xprt *xprt = 56665f27f38SDavid Howells container_of(work, struct rpc_xprt, task_cleanup); 5671da177e4SLinus Torvalds 568a246b010SChuck Lever xprt->ops->close(xprt); 56966af1e55STrond Myklebust clear_bit(XPRT_CLOSE_WAIT, &xprt->state); 5701da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds 5739903cd1cSChuck Lever /** 57462da3b24STrond Myklebust * xprt_disconnect_done - mark a transport as disconnected 5759903cd1cSChuck Lever * @xprt: transport to flag for disconnect 5769903cd1cSChuck Lever * 5771da177e4SLinus Torvalds */ 57862da3b24STrond Myklebust void xprt_disconnect_done(struct rpc_xprt *xprt) 5791da177e4SLinus Torvalds { 5801da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 5814a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5821da177e4SLinus Torvalds xprt_clear_connected(xprt); 58344fbac22SChuck Lever xprt_wake_pending_tasks(xprt, -ENOTCONN); 5844a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 5851da177e4SLinus Torvalds } 58662da3b24STrond Myklebust EXPORT_SYMBOL_GPL(xprt_disconnect_done); 5871da177e4SLinus Torvalds 58866af1e55STrond Myklebust /** 58966af1e55STrond Myklebust * xprt_force_disconnect - force a transport to disconnect 59066af1e55STrond Myklebust * @xprt: transport to disconnect 59166af1e55STrond Myklebust * 59266af1e55STrond Myklebust */ 59366af1e55STrond Myklebust void xprt_force_disconnect(struct rpc_xprt *xprt) 59466af1e55STrond Myklebust { 59566af1e55STrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 59666af1e55STrond Myklebust spin_lock_bh(&xprt->transport_lock); 59766af1e55STrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 59866af1e55STrond Myklebust /* Try to schedule an autoclose RPC call */ 59966af1e55STrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 60066af1e55STrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 601fda13939STrond Myklebust xprt_wake_pending_tasks(xprt, -ENOTCONN); 60266af1e55STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 60366af1e55STrond Myklebust } 60466af1e55STrond Myklebust 6057c1d71cfSTrond Myklebust /** 6067c1d71cfSTrond Myklebust * xprt_conditional_disconnect - force a transport to disconnect 6077c1d71cfSTrond Myklebust * @xprt: transport to disconnect 6087c1d71cfSTrond Myklebust * @cookie: 'connection cookie' 6097c1d71cfSTrond Myklebust * 6107c1d71cfSTrond Myklebust * This attempts to break the connection if and only if 'cookie' matches 6117c1d71cfSTrond Myklebust * the current transport 'connection cookie'. It ensures that we don't 6127c1d71cfSTrond Myklebust * try to break the connection more than once when we need to retransmit 6137c1d71cfSTrond Myklebust * a batch of RPC requests. 6147c1d71cfSTrond Myklebust * 6157c1d71cfSTrond Myklebust */ 6167c1d71cfSTrond Myklebust void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) 6177c1d71cfSTrond Myklebust { 6187c1d71cfSTrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 6197c1d71cfSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 6207c1d71cfSTrond Myklebust if (cookie != xprt->connect_cookie) 6217c1d71cfSTrond Myklebust goto out; 6227c1d71cfSTrond Myklebust if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) 6237c1d71cfSTrond Myklebust goto out; 6247c1d71cfSTrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 6257c1d71cfSTrond Myklebust /* Try to schedule an autoclose RPC call */ 6267c1d71cfSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 6277c1d71cfSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6287c1d71cfSTrond Myklebust xprt_wake_pending_tasks(xprt, -ENOTCONN); 6297c1d71cfSTrond Myklebust out: 6307c1d71cfSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 6317c1d71cfSTrond Myklebust } 6327c1d71cfSTrond Myklebust 6331da177e4SLinus Torvalds static void 6341da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 6351da177e4SLinus Torvalds { 6361da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 6371da177e4SLinus Torvalds 6384a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 6391da177e4SLinus Torvalds if (!list_empty(&xprt->recv) || xprt->shutdown) 6401da177e4SLinus Torvalds goto out_abort; 6412226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 6421da177e4SLinus Torvalds goto out_abort; 6434a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6442226feb6SChuck Lever if (xprt_connecting(xprt)) 6451da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 6461da177e4SLinus Torvalds else 647c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6481da177e4SLinus Torvalds return; 6491da177e4SLinus Torvalds out_abort: 6504a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6511da177e4SLinus Torvalds } 6521da177e4SLinus Torvalds 6539903cd1cSChuck Lever /** 6549903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 6559903cd1cSChuck Lever * @task: RPC task that is requesting the connect 6561da177e4SLinus Torvalds * 6571da177e4SLinus Torvalds */ 6581da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 6591da177e4SLinus Torvalds { 6601da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 6611da177e4SLinus Torvalds 66246121cf7SChuck Lever dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, 6631da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 6641da177e4SLinus Torvalds 665ec739ef0SChuck Lever if (!xprt_bound(xprt)) { 66601d37c42STrond Myklebust task->tk_status = -EAGAIN; 6671da177e4SLinus Torvalds return; 6681da177e4SLinus Torvalds } 6691da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 6701da177e4SLinus Torvalds return; 6711da177e4SLinus Torvalds if (xprt_connected(xprt)) 672a246b010SChuck Lever xprt_release_write(xprt, task); 673a246b010SChuck Lever else { 6741da177e4SLinus Torvalds if (task->tk_rqstp) 6751da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 6761da177e4SLinus Torvalds 67703bf4b70SChuck Lever task->tk_timeout = xprt->connect_timeout; 6785d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_connect_status); 679262ca07dSChuck Lever xprt->stat.connect_start = jiffies; 680a246b010SChuck Lever xprt->ops->connect(task); 6811da177e4SLinus Torvalds } 6821da177e4SLinus Torvalds return; 6831da177e4SLinus Torvalds } 6841da177e4SLinus Torvalds 6859903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 6861da177e4SLinus Torvalds { 6871da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 6881da177e4SLinus Torvalds 689cd983ef8SChuck Lever if (task->tk_status == 0) { 690262ca07dSChuck Lever xprt->stat.connect_count++; 691262ca07dSChuck Lever xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; 69246121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection established\n", 6931da177e4SLinus Torvalds task->tk_pid); 6941da177e4SLinus Torvalds return; 6951da177e4SLinus Torvalds } 6961da177e4SLinus Torvalds 6971da177e4SLinus Torvalds switch (task->tk_status) { 6981da177e4SLinus Torvalds case -ENOTCONN: 69946121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection broken\n", 70023475d66SChuck Lever task->tk_pid); 70123475d66SChuck Lever break; 7021da177e4SLinus Torvalds case -ETIMEDOUT: 70346121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connect attempt timed " 70446121cf7SChuck Lever "out\n", task->tk_pid); 7051da177e4SLinus Torvalds break; 7061da177e4SLinus Torvalds default: 70746121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: error %d connecting to " 70846121cf7SChuck Lever "server %s\n", task->tk_pid, -task->tk_status, 70946121cf7SChuck Lever task->tk_client->cl_server); 7101da177e4SLinus Torvalds xprt_release_write(xprt, task); 71123475d66SChuck Lever task->tk_status = -EIO; 71223475d66SChuck Lever } 7131da177e4SLinus Torvalds } 7141da177e4SLinus Torvalds 7159903cd1cSChuck Lever /** 7169903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 7179903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 7189903cd1cSChuck Lever * @xid: RPC XID of incoming reply 7199903cd1cSChuck Lever * 7201da177e4SLinus Torvalds */ 721d8ed029dSAlexey Dobriyan struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) 7221da177e4SLinus Torvalds { 7231da177e4SLinus Torvalds struct list_head *pos; 7241da177e4SLinus Torvalds 7251da177e4SLinus Torvalds list_for_each(pos, &xprt->recv) { 7261da177e4SLinus Torvalds struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list); 727262ca07dSChuck Lever if (entry->rq_xid == xid) 728262ca07dSChuck Lever return entry; 7291da177e4SLinus Torvalds } 73046121cf7SChuck Lever 73146121cf7SChuck Lever dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", 73246121cf7SChuck Lever ntohl(xid)); 733262ca07dSChuck Lever xprt->stat.bad_xids++; 734262ca07dSChuck Lever return NULL; 7351da177e4SLinus Torvalds } 73612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_lookup_rqst); 7371da177e4SLinus Torvalds 7389903cd1cSChuck Lever /** 7391570c1e4SChuck Lever * xprt_update_rtt - update an RPC client's RTT state after receiving a reply 7401570c1e4SChuck Lever * @task: RPC request that recently completed 7419903cd1cSChuck Lever * 7421da177e4SLinus Torvalds */ 7431570c1e4SChuck Lever void xprt_update_rtt(struct rpc_task *task) 7441da177e4SLinus Torvalds { 7451570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 7461570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 7471da177e4SLinus Torvalds unsigned timer = task->tk_msg.rpc_proc->p_timer; 7481570c1e4SChuck Lever 7491da177e4SLinus Torvalds if (timer) { 7501da177e4SLinus Torvalds if (req->rq_ntrans == 1) 7511570c1e4SChuck Lever rpc_update_rtt(rtt, timer, 7521da177e4SLinus Torvalds (long)jiffies - req->rq_xtime); 7531570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 7541da177e4SLinus Torvalds } 7551da177e4SLinus Torvalds } 75612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_update_rtt); 7571da177e4SLinus Torvalds 7581570c1e4SChuck Lever /** 7591570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 7601570c1e4SChuck Lever * @task: RPC request that recently completed 7611570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 7621570c1e4SChuck Lever * 7631570c1e4SChuck Lever * Caller holds transport lock. 7641570c1e4SChuck Lever */ 7651570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 7661570c1e4SChuck Lever { 7671570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 768fda13939STrond Myklebust struct rpc_xprt *xprt = req->rq_xprt; 7691da177e4SLinus Torvalds 7701570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 7711570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 7721da177e4SLinus Torvalds 773fda13939STrond Myklebust xprt->stat.recvs++; 774ef759a2eSChuck Lever task->tk_rtt = (long)jiffies - req->rq_xtime; 775ef759a2eSChuck Lever 7761da177e4SLinus Torvalds list_del_init(&req->rq_list); 7771e799b67STrond Myklebust req->rq_private_buf.len = copied; 77843ac3f29STrond Myklebust /* Ensure all writes are done before we update req->rq_received */ 77943ac3f29STrond Myklebust smp_wmb(); 7801e799b67STrond Myklebust req->rq_received = copied; 781fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, task); 7821da177e4SLinus Torvalds } 78312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_complete_rqst); 7841da177e4SLinus Torvalds 78546c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 7861da177e4SLinus Torvalds { 7871da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 7881da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 7891da177e4SLinus Torvalds 7905d00837bSTrond Myklebust if (task->tk_status != -ETIMEDOUT) 7915d00837bSTrond Myklebust return; 79246121cf7SChuck Lever dprintk("RPC: %5u xprt_timer\n", task->tk_pid); 79346c0ee8bSChuck Lever 7945d00837bSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 79546c0ee8bSChuck Lever if (!req->rq_received) { 79646c0ee8bSChuck Lever if (xprt->ops->timer) 79746c0ee8bSChuck Lever xprt->ops->timer(task); 7985d00837bSTrond Myklebust } else 7995d00837bSTrond Myklebust task->tk_status = 0; 8005d00837bSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 8011da177e4SLinus Torvalds } 8021da177e4SLinus Torvalds 8039903cd1cSChuck Lever /** 8049903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 8059903cd1cSChuck Lever * @task: RPC task about to send a request 8069903cd1cSChuck Lever * 8071da177e4SLinus Torvalds */ 8089903cd1cSChuck Lever int xprt_prepare_transmit(struct rpc_task *task) 8091da177e4SLinus Torvalds { 8101da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8111da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 8121da177e4SLinus Torvalds int err = 0; 8131da177e4SLinus Torvalds 81446121cf7SChuck Lever dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); 8151da177e4SLinus Torvalds 8164a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 8171da177e4SLinus Torvalds if (req->rq_received && !req->rq_bytes_sent) { 8181da177e4SLinus Torvalds err = req->rq_received; 8191da177e4SLinus Torvalds goto out_unlock; 8201da177e4SLinus Torvalds } 82112a80469SChuck Lever if (!xprt->ops->reserve_xprt(task)) { 8221da177e4SLinus Torvalds err = -EAGAIN; 8231da177e4SLinus Torvalds goto out_unlock; 8241da177e4SLinus Torvalds } 8251da177e4SLinus Torvalds 8261da177e4SLinus Torvalds if (!xprt_connected(xprt)) { 8271da177e4SLinus Torvalds err = -ENOTCONN; 8281da177e4SLinus Torvalds goto out_unlock; 8291da177e4SLinus Torvalds } 8301da177e4SLinus Torvalds out_unlock: 8314a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 8321da177e4SLinus Torvalds return err; 8331da177e4SLinus Torvalds } 8341da177e4SLinus Torvalds 835e0ab53deSTrond Myklebust void xprt_end_transmit(struct rpc_task *task) 8365e5ce5beSTrond Myklebust { 837e0ab53deSTrond Myklebust xprt_release_write(task->tk_xprt, task); 8385e5ce5beSTrond Myklebust } 8395e5ce5beSTrond Myklebust 8409903cd1cSChuck Lever /** 8419903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 8429903cd1cSChuck Lever * @task: controlling RPC task 8439903cd1cSChuck Lever * 8449903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 8459903cd1cSChuck Lever */ 8469903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 8471da177e4SLinus Torvalds { 8481da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8491da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 850a246b010SChuck Lever int status; 8511da177e4SLinus Torvalds 85246121cf7SChuck Lever dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 8531da177e4SLinus Torvalds 8541da177e4SLinus Torvalds if (!req->rq_received) { 8551da177e4SLinus Torvalds if (list_empty(&req->rq_list)) { 8564a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 8571da177e4SLinus Torvalds /* Update the softirq receive buffer */ 8581da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 8591da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 8601da177e4SLinus Torvalds /* Add request to the receive list */ 8611da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 8624a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 8631da177e4SLinus Torvalds xprt_reset_majortimeo(req); 8640f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 8650f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 8661da177e4SLinus Torvalds } 8671da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 8681da177e4SLinus Torvalds return; 8691da177e4SLinus Torvalds 8707c1d71cfSTrond Myklebust req->rq_connect_cookie = xprt->connect_cookie; 871b22602a6SChuck Lever req->rq_xtime = jiffies; 872a246b010SChuck Lever status = xprt->ops->send_request(task); 873fe3aca29SChuck Lever if (status == 0) { 87446121cf7SChuck Lever dprintk("RPC: %5u xmit complete\n", task->tk_pid); 875fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 876262ca07dSChuck Lever 877fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 878262ca07dSChuck Lever 879262ca07dSChuck Lever xprt->stat.sends++; 880262ca07dSChuck Lever xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; 881262ca07dSChuck Lever xprt->stat.bklog_u += xprt->backlog.qlen; 882262ca07dSChuck Lever 883fe3aca29SChuck Lever /* Don't race with disconnect */ 884fe3aca29SChuck Lever if (!xprt_connected(xprt)) 885fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 886fe3aca29SChuck Lever else if (!req->rq_received) 8875d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_timer); 888fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 889fe3aca29SChuck Lever return; 890fe3aca29SChuck Lever } 8911da177e4SLinus Torvalds 8921da177e4SLinus Torvalds /* Note: at this point, task->tk_sleeping has not yet been set, 8931da177e4SLinus Torvalds * hence there is no danger of the waking up task being put on 8941da177e4SLinus Torvalds * schedq, and being picked up by a parallel run of rpciod(). 8951da177e4SLinus Torvalds */ 8961da177e4SLinus Torvalds task->tk_status = status; 897e0ab53deSTrond Myklebust if (status == -ECONNREFUSED) 8985d00837bSTrond Myklebust rpc_sleep_on(&xprt->sending, task, NULL); 8991da177e4SLinus Torvalds } 9001da177e4SLinus Torvalds 9019903cd1cSChuck Lever static inline void do_xprt_reserve(struct rpc_task *task) 9021da177e4SLinus Torvalds { 9031da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 9041da177e4SLinus Torvalds 9051da177e4SLinus Torvalds task->tk_status = 0; 9061da177e4SLinus Torvalds if (task->tk_rqstp) 9071da177e4SLinus Torvalds return; 9081da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 9091da177e4SLinus Torvalds struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 9101da177e4SLinus Torvalds list_del_init(&req->rq_list); 9111da177e4SLinus Torvalds task->tk_rqstp = req; 9121da177e4SLinus Torvalds xprt_request_init(task, xprt); 9131da177e4SLinus Torvalds return; 9141da177e4SLinus Torvalds } 9151da177e4SLinus Torvalds dprintk("RPC: waiting for request slot\n"); 9161da177e4SLinus Torvalds task->tk_status = -EAGAIN; 9171da177e4SLinus Torvalds task->tk_timeout = 0; 9185d00837bSTrond Myklebust rpc_sleep_on(&xprt->backlog, task, NULL); 9191da177e4SLinus Torvalds } 9201da177e4SLinus Torvalds 9219903cd1cSChuck Lever /** 9229903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 9239903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 9249903cd1cSChuck Lever * 9259903cd1cSChuck Lever * If no more slots are available, place the task on the transport's 9269903cd1cSChuck Lever * backlog queue. 9279903cd1cSChuck Lever */ 9289903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 9291da177e4SLinus Torvalds { 9301da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvalds task->tk_status = -EIO; 9335dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 9341da177e4SLinus Torvalds do_xprt_reserve(task); 9355dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 9361da177e4SLinus Torvalds } 9371da177e4SLinus Torvalds 938d8ed029dSAlexey Dobriyan static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) 9391da177e4SLinus Torvalds { 9401da177e4SLinus Torvalds return xprt->xid++; 9411da177e4SLinus Torvalds } 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 9441da177e4SLinus Torvalds { 945bf3fcf89SChuck Lever xprt->xid = net_random(); 9461da177e4SLinus Torvalds } 9471da177e4SLinus Torvalds 9489903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 9491da177e4SLinus Torvalds { 9501da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9511da177e4SLinus Torvalds 952ba7392bbSTrond Myklebust req->rq_timeout = task->tk_client->cl_timeout->to_initval; 9531da177e4SLinus Torvalds req->rq_task = task; 9541da177e4SLinus Torvalds req->rq_xprt = xprt; 95502107148SChuck Lever req->rq_buffer = NULL; 9561da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 957ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf = NULL; 958da45828eSTrond Myklebust xprt_reset_majortimeo(req); 95946121cf7SChuck Lever dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, 9601da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 9611da177e4SLinus Torvalds } 9621da177e4SLinus Torvalds 9639903cd1cSChuck Lever /** 9649903cd1cSChuck Lever * xprt_release - release an RPC request slot 9659903cd1cSChuck Lever * @task: task which is finished with the slot 9669903cd1cSChuck Lever * 9671da177e4SLinus Torvalds */ 9689903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 9691da177e4SLinus Torvalds { 9701da177e4SLinus Torvalds struct rpc_xprt *xprt = task->tk_xprt; 9711da177e4SLinus Torvalds struct rpc_rqst *req; 9721da177e4SLinus Torvalds 9731da177e4SLinus Torvalds if (!(req = task->tk_rqstp)) 9741da177e4SLinus Torvalds return; 97511c556b3SChuck Lever rpc_count_iostats(task); 9764a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 97749e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 978a58dd398SChuck Lever if (xprt->ops->release_request) 979a58dd398SChuck Lever xprt->ops->release_request(task); 9801da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 9811da177e4SLinus Torvalds list_del(&req->rq_list); 9821da177e4SLinus Torvalds xprt->last_used = jiffies; 9830065db32STrond Myklebust if (list_empty(&xprt->recv)) 984a246b010SChuck Lever mod_timer(&xprt->timer, 98503bf4b70SChuck Lever xprt->last_used + xprt->idle_timeout); 9864a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 987c5a4dd8bSChuck Lever xprt->ops->buf_free(req->rq_buffer); 9881da177e4SLinus Torvalds task->tk_rqstp = NULL; 989ead5e1c2SJ. Bruce Fields if (req->rq_release_snd_buf) 990ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf(req); 9911da177e4SLinus Torvalds memset(req, 0, sizeof(*req)); /* mark unused */ 9921da177e4SLinus Torvalds 99346121cf7SChuck Lever dprintk("RPC: %5u release request %p\n", task->tk_pid, req); 9941da177e4SLinus Torvalds 9955dc07727SChuck Lever spin_lock(&xprt->reserve_lock); 9961da177e4SLinus Torvalds list_add(&req->rq_list, &xprt->free); 997555ee3afSChuck Lever rpc_wake_up_next(&xprt->backlog); 9985dc07727SChuck Lever spin_unlock(&xprt->reserve_lock); 9991da177e4SLinus Torvalds } 10001da177e4SLinus Torvalds 10019903cd1cSChuck Lever /** 1002c2866763SChuck Lever * xprt_create_transport - create an RPC transport 100396802a09SFrank van Maarseveen * @args: rpc transport creation arguments 1004c2866763SChuck Lever * 1005c2866763SChuck Lever */ 10063c341b0bS\"Talpey, Thomas\ struct rpc_xprt *xprt_create_transport(struct xprt_create *args) 1007c2866763SChuck Lever { 1008c2866763SChuck Lever struct rpc_xprt *xprt; 1009c2866763SChuck Lever struct rpc_rqst *req; 1010bc25571eS\"Talpey, Thomas\ struct xprt_class *t; 1011c2866763SChuck Lever 1012bc25571eS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 1013bc25571eS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 10144fa016ebS\"Talpey, Thomas\ if (t->ident == args->ident) { 1015bc25571eS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 1016bc25571eS\"Talpey, Thomas\ goto found; 1017c2866763SChuck Lever } 1018bc25571eS\"Talpey, Thomas\ } 1019bc25571eS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 10204fa016ebS\"Talpey, Thomas\ printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); 1021bc25571eS\"Talpey, Thomas\ return ERR_PTR(-EIO); 1022bc25571eS\"Talpey, Thomas\ 1023bc25571eS\"Talpey, Thomas\ found: 1024bc25571eS\"Talpey, Thomas\ xprt = t->setup(args); 1025c8541ecdSChuck Lever if (IS_ERR(xprt)) { 1026c8541ecdSChuck Lever dprintk("RPC: xprt_create_transport: failed, %ld\n", 1027c8541ecdSChuck Lever -PTR_ERR(xprt)); 1028c8541ecdSChuck Lever return xprt; 1029c2866763SChuck Lever } 1030c2866763SChuck Lever 10316b6ca86bSTrond Myklebust kref_init(&xprt->kref); 1032c2866763SChuck Lever spin_lock_init(&xprt->transport_lock); 1033c2866763SChuck Lever spin_lock_init(&xprt->reserve_lock); 1034c2866763SChuck Lever 1035c2866763SChuck Lever INIT_LIST_HEAD(&xprt->free); 1036c2866763SChuck Lever INIT_LIST_HEAD(&xprt->recv); 103765f27f38SDavid Howells INIT_WORK(&xprt->task_cleanup, xprt_autoclose); 1038b24b8a24SPavel Emelyanov setup_timer(&xprt->timer, xprt_init_autodisconnect, 1039b24b8a24SPavel Emelyanov (unsigned long)xprt); 1040c2866763SChuck Lever xprt->last_used = jiffies; 1041c2866763SChuck Lever xprt->cwnd = RPC_INITCWND; 1042a509050bSChuck Lever xprt->bind_index = 0; 1043c2866763SChuck Lever 1044c2866763SChuck Lever rpc_init_wait_queue(&xprt->binding, "xprt_binding"); 1045c2866763SChuck Lever rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 1046c2866763SChuck Lever rpc_init_wait_queue(&xprt->sending, "xprt_sending"); 1047c2866763SChuck Lever rpc_init_wait_queue(&xprt->resend, "xprt_resend"); 1048c2866763SChuck Lever rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 1049c2866763SChuck Lever 1050c2866763SChuck Lever /* initialize free list */ 1051c2866763SChuck Lever for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--) 1052c2866763SChuck Lever list_add(&req->rq_list, &xprt->free); 1053c2866763SChuck Lever 1054c2866763SChuck Lever xprt_init_xid(xprt); 1055c2866763SChuck Lever 1056c2866763SChuck Lever dprintk("RPC: created transport %p with %u slots\n", xprt, 1057c2866763SChuck Lever xprt->max_reqs); 1058c2866763SChuck Lever 1059c2866763SChuck Lever return xprt; 1060c2866763SChuck Lever } 1061c2866763SChuck Lever 10629903cd1cSChuck Lever /** 10639903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 10646b6ca86bSTrond Myklebust * @kref: kref for the transport to destroy 10659903cd1cSChuck Lever * 10661da177e4SLinus Torvalds */ 10676b6ca86bSTrond Myklebust static void xprt_destroy(struct kref *kref) 10681da177e4SLinus Torvalds { 10696b6ca86bSTrond Myklebust struct rpc_xprt *xprt = container_of(kref, struct rpc_xprt, kref); 10706b6ca86bSTrond Myklebust 10711da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 10720065db32STrond Myklebust xprt->shutdown = 1; 10730065db32STrond Myklebust del_timer_sync(&xprt->timer); 1074c8541ecdSChuck Lever 1075f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->binding); 1076f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->pending); 1077f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->sending); 1078f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->resend); 1079f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->backlog); 1080c8541ecdSChuck Lever /* 1081c8541ecdSChuck Lever * Tear down transport state and free the rpc_xprt 1082c8541ecdSChuck Lever */ 1083a246b010SChuck Lever xprt->ops->destroy(xprt); 10846b6ca86bSTrond Myklebust } 10851da177e4SLinus Torvalds 10866b6ca86bSTrond Myklebust /** 10876b6ca86bSTrond Myklebust * xprt_put - release a reference to an RPC transport. 10886b6ca86bSTrond Myklebust * @xprt: pointer to the transport 10896b6ca86bSTrond Myklebust * 10906b6ca86bSTrond Myklebust */ 10916b6ca86bSTrond Myklebust void xprt_put(struct rpc_xprt *xprt) 10926b6ca86bSTrond Myklebust { 10936b6ca86bSTrond Myklebust kref_put(&xprt->kref, xprt_destroy); 10946b6ca86bSTrond Myklebust } 10956b6ca86bSTrond Myklebust 10966b6ca86bSTrond Myklebust /** 10976b6ca86bSTrond Myklebust * xprt_get - return a reference to an RPC transport. 10986b6ca86bSTrond Myklebust * @xprt: pointer to the transport 10996b6ca86bSTrond Myklebust * 11006b6ca86bSTrond Myklebust */ 11016b6ca86bSTrond Myklebust struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) 11026b6ca86bSTrond Myklebust { 11036b6ca86bSTrond Myklebust kref_get(&xprt->kref); 11046b6ca86bSTrond Myklebust return xprt; 11051da177e4SLinus Torvalds } 1106