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 1555ae1aabSRicardo Labiaga * transport's wait list. At the same time, if a reply is expected, 1655ae1aabSRicardo Labiaga * it installs a timer that is run after the packet's timeout has 1755ae1aabSRicardo Labiaga * expired. 181da177e4SLinus Torvalds * - When a packet arrives, the data_ready handler walks the list of 1955aa4f58SChuck Lever * pending requests for that transport. If a matching XID is found, the 201da177e4SLinus Torvalds * caller is woken up, and the timer removed. 211da177e4SLinus Torvalds * - When no reply arrives within the timeout interval, the timer is 221da177e4SLinus Torvalds * fired by the kernel and runs xprt_timer(). It either adjusts the 231da177e4SLinus Torvalds * timeout values (minor timeout) or wakes up the caller with a status 241da177e4SLinus Torvalds * of -ETIMEDOUT. 251da177e4SLinus Torvalds * - When the caller receives a notification from RPC that a reply arrived, 261da177e4SLinus Torvalds * it should release the RPC slot, and process the reply. 271da177e4SLinus Torvalds * If the call timed out, it may choose to retry the operation by 281da177e4SLinus Torvalds * adjusting the initial timeout value, and simply calling rpc_call 291da177e4SLinus Torvalds * again. 301da177e4SLinus Torvalds * 311da177e4SLinus Torvalds * Support for async RPC is done through a set of RPC-specific scheduling 321da177e4SLinus Torvalds * primitives that `transparently' work for processes as well as async 331da177e4SLinus Torvalds * tasks that rely on callbacks. 341da177e4SLinus Torvalds * 351da177e4SLinus Torvalds * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> 3655aa4f58SChuck Lever * 3755aa4f58SChuck Lever * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> 381da177e4SLinus Torvalds */ 391da177e4SLinus Torvalds 40a246b010SChuck Lever #include <linux/module.h> 41a246b010SChuck Lever 421da177e4SLinus Torvalds #include <linux/types.h> 43a246b010SChuck Lever #include <linux/interrupt.h> 441da177e4SLinus Torvalds #include <linux/workqueue.h> 45bf3fcf89SChuck Lever #include <linux/net.h> 46ff839970SChuck Lever #include <linux/ktime.h> 471da177e4SLinus Torvalds 48a246b010SChuck Lever #include <linux/sunrpc/clnt.h> 4911c556b3SChuck Lever #include <linux/sunrpc/metrics.h> 50c9acb42eSTrond Myklebust #include <linux/sunrpc/bc_xprt.h> 51fda1bfefSTrond Myklebust #include <linux/rcupdate.h> 521da177e4SLinus Torvalds 533705ad64SJeff Layton #include <trace/events/sunrpc.h> 543705ad64SJeff Layton 5555ae1aabSRicardo Labiaga #include "sunrpc.h" 5655ae1aabSRicardo Labiaga 571da177e4SLinus Torvalds /* 581da177e4SLinus Torvalds * Local variables 591da177e4SLinus Torvalds */ 601da177e4SLinus Torvalds 61f895b252SJeff Layton #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 621da177e4SLinus Torvalds # define RPCDBG_FACILITY RPCDBG_XPRT 631da177e4SLinus Torvalds #endif 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /* 661da177e4SLinus Torvalds * Local functions 671da177e4SLinus Torvalds */ 6821de0a95STrond Myklebust static void xprt_init(struct rpc_xprt *xprt, struct net *net); 691da177e4SLinus Torvalds static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); 701da177e4SLinus Torvalds static void xprt_connect_status(struct rpc_task *task); 711da177e4SLinus Torvalds static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); 7229807318SNeil Brown static void __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *); 734e0038b6STrond Myklebust static void xprt_destroy(struct rpc_xprt *xprt); 741da177e4SLinus Torvalds 755ba03e82SJiri Slaby static DEFINE_SPINLOCK(xprt_list_lock); 7681c098afS\"Talpey, Thomas\ static LIST_HEAD(xprt_list); 7781c098afS\"Talpey, Thomas\ 7812a80469SChuck Lever /** 7981c098afS\"Talpey, Thomas\ * xprt_register_transport - register a transport implementation 8081c098afS\"Talpey, Thomas\ * @transport: transport to register 8181c098afS\"Talpey, Thomas\ * 8281c098afS\"Talpey, Thomas\ * If a transport implementation is loaded as a kernel module, it can 8381c098afS\"Talpey, Thomas\ * call this interface to make itself known to the RPC client. 8481c098afS\"Talpey, Thomas\ * 8581c098afS\"Talpey, Thomas\ * Returns: 8681c098afS\"Talpey, Thomas\ * 0: transport successfully registered 8781c098afS\"Talpey, Thomas\ * -EEXIST: transport already registered 8881c098afS\"Talpey, Thomas\ * -EINVAL: transport module being unloaded 8981c098afS\"Talpey, Thomas\ */ 9081c098afS\"Talpey, Thomas\ int xprt_register_transport(struct xprt_class *transport) 9181c098afS\"Talpey, Thomas\ { 9281c098afS\"Talpey, Thomas\ struct xprt_class *t; 9381c098afS\"Talpey, Thomas\ int result; 9481c098afS\"Talpey, Thomas\ 9581c098afS\"Talpey, Thomas\ result = -EEXIST; 9681c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 9781c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 9881c098afS\"Talpey, Thomas\ /* don't register the same transport class twice */ 994fa016ebS\"Talpey, Thomas\ if (t->ident == transport->ident) 10081c098afS\"Talpey, Thomas\ goto out; 10181c098afS\"Talpey, Thomas\ } 10281c098afS\"Talpey, Thomas\ 10381c098afS\"Talpey, Thomas\ list_add_tail(&transport->list, &xprt_list); 10481c098afS\"Talpey, Thomas\ printk(KERN_INFO "RPC: Registered %s transport module.\n", 10581c098afS\"Talpey, Thomas\ transport->name); 10681c098afS\"Talpey, Thomas\ result = 0; 10781c098afS\"Talpey, Thomas\ 10881c098afS\"Talpey, Thomas\ out: 10981c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 11081c098afS\"Talpey, Thomas\ return result; 11181c098afS\"Talpey, Thomas\ } 11281c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_register_transport); 11381c098afS\"Talpey, Thomas\ 11481c098afS\"Talpey, Thomas\ /** 11581c098afS\"Talpey, Thomas\ * xprt_unregister_transport - unregister a transport implementation 11665b6e42cSRandy Dunlap * @transport: transport to unregister 11781c098afS\"Talpey, Thomas\ * 11881c098afS\"Talpey, Thomas\ * Returns: 11981c098afS\"Talpey, Thomas\ * 0: transport successfully unregistered 12081c098afS\"Talpey, Thomas\ * -ENOENT: transport never registered 12181c098afS\"Talpey, Thomas\ */ 12281c098afS\"Talpey, Thomas\ int xprt_unregister_transport(struct xprt_class *transport) 12381c098afS\"Talpey, Thomas\ { 12481c098afS\"Talpey, Thomas\ struct xprt_class *t; 12581c098afS\"Talpey, Thomas\ int result; 12681c098afS\"Talpey, Thomas\ 12781c098afS\"Talpey, Thomas\ result = 0; 12881c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 12981c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 13081c098afS\"Talpey, Thomas\ if (t == transport) { 13181c098afS\"Talpey, Thomas\ printk(KERN_INFO 13281c098afS\"Talpey, Thomas\ "RPC: Unregistered %s transport module.\n", 13381c098afS\"Talpey, Thomas\ transport->name); 13481c098afS\"Talpey, Thomas\ list_del_init(&transport->list); 13581c098afS\"Talpey, Thomas\ goto out; 13681c098afS\"Talpey, Thomas\ } 13781c098afS\"Talpey, Thomas\ } 13881c098afS\"Talpey, Thomas\ result = -ENOENT; 13981c098afS\"Talpey, Thomas\ 14081c098afS\"Talpey, Thomas\ out: 14181c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 14281c098afS\"Talpey, Thomas\ return result; 14381c098afS\"Talpey, Thomas\ } 14481c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_unregister_transport); 14581c098afS\"Talpey, Thomas\ 14681c098afS\"Talpey, Thomas\ /** 147441e3e24STom Talpey * xprt_load_transport - load a transport implementation 148441e3e24STom Talpey * @transport_name: transport to load 149441e3e24STom Talpey * 150441e3e24STom Talpey * Returns: 151441e3e24STom Talpey * 0: transport successfully loaded 152441e3e24STom Talpey * -ENOENT: transport module not available 153441e3e24STom Talpey */ 154441e3e24STom Talpey int xprt_load_transport(const char *transport_name) 155441e3e24STom Talpey { 156441e3e24STom Talpey struct xprt_class *t; 157441e3e24STom Talpey int result; 158441e3e24STom Talpey 159441e3e24STom Talpey result = 0; 160441e3e24STom Talpey spin_lock(&xprt_list_lock); 161441e3e24STom Talpey list_for_each_entry(t, &xprt_list, list) { 162441e3e24STom Talpey if (strcmp(t->name, transport_name) == 0) { 163441e3e24STom Talpey spin_unlock(&xprt_list_lock); 164441e3e24STom Talpey goto out; 165441e3e24STom Talpey } 166441e3e24STom Talpey } 167441e3e24STom Talpey spin_unlock(&xprt_list_lock); 168ef7ffe8fSAlex Riesen result = request_module("xprt%s", transport_name); 169441e3e24STom Talpey out: 170441e3e24STom Talpey return result; 171441e3e24STom Talpey } 172441e3e24STom Talpey EXPORT_SYMBOL_GPL(xprt_load_transport); 173441e3e24STom Talpey 174441e3e24STom Talpey /** 17512a80469SChuck Lever * xprt_reserve_xprt - serialize write access to transports 17612a80469SChuck Lever * @task: task that is requesting access to the transport 177177c27bfSRandy Dunlap * @xprt: pointer to the target transport 17812a80469SChuck Lever * 17912a80469SChuck Lever * This prevents mixing the payload of separate requests, and prevents 18012a80469SChuck Lever * transport connects from colliding with writes. No congestion control 18112a80469SChuck Lever * is provided. 1821da177e4SLinus Torvalds */ 18343cedbf0STrond Myklebust int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 1841da177e4SLinus Torvalds { 18512a80469SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 18634006ceeSTrond Myklebust int priority; 18712a80469SChuck Lever 18812a80469SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 18912a80469SChuck Lever if (task == xprt->snd_task) 19012a80469SChuck Lever return 1; 19112a80469SChuck Lever goto out_sleep; 19212a80469SChuck Lever } 19312a80469SChuck Lever xprt->snd_task = task; 19492551948STrond Myklebust if (req != NULL) 19512a80469SChuck Lever req->rq_ntrans++; 1964d4a76f3Sj223yang@asset.uwaterloo.ca 19712a80469SChuck Lever return 1; 19812a80469SChuck Lever 19912a80469SChuck Lever out_sleep: 20046121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", 20112a80469SChuck Lever task->tk_pid, xprt); 20212a80469SChuck Lever task->tk_timeout = 0; 20312a80469SChuck Lever task->tk_status = -EAGAIN; 20434006ceeSTrond Myklebust if (req == NULL) 20534006ceeSTrond Myklebust priority = RPC_PRIORITY_LOW; 20634006ceeSTrond Myklebust else if (!req->rq_ntrans) 20734006ceeSTrond Myklebust priority = RPC_PRIORITY_NORMAL; 20812a80469SChuck Lever else 20934006ceeSTrond Myklebust priority = RPC_PRIORITY_HIGH; 21034006ceeSTrond Myklebust rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); 21112a80469SChuck Lever return 0; 21212a80469SChuck Lever } 21312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt); 21412a80469SChuck Lever 215632e3bdcSTrond Myklebust static void xprt_clear_locked(struct rpc_xprt *xprt) 216632e3bdcSTrond Myklebust { 217632e3bdcSTrond Myklebust xprt->snd_task = NULL; 218d19751e7STrond Myklebust if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { 2194e857c58SPeter Zijlstra smp_mb__before_atomic(); 220632e3bdcSTrond Myklebust clear_bit(XPRT_LOCKED, &xprt->state); 2214e857c58SPeter Zijlstra smp_mb__after_atomic(); 222632e3bdcSTrond Myklebust } else 223c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 224632e3bdcSTrond Myklebust } 225632e3bdcSTrond Myklebust 22612a80469SChuck Lever /* 22712a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 22812a80469SChuck Lever * @task: task that is requesting access to the transport 22912a80469SChuck Lever * 23012a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 23112a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 23212a80469SChuck Lever * woken up and given access to the transport. 23312a80469SChuck Lever */ 23443cedbf0STrond Myklebust int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 23512a80469SChuck Lever { 2361da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 23734006ceeSTrond Myklebust int priority; 2381da177e4SLinus Torvalds 2392226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 2401da177e4SLinus Torvalds if (task == xprt->snd_task) 2411da177e4SLinus Torvalds return 1; 2421da177e4SLinus Torvalds goto out_sleep; 2431da177e4SLinus Torvalds } 24443cedbf0STrond Myklebust if (req == NULL) { 24543cedbf0STrond Myklebust xprt->snd_task = task; 24643cedbf0STrond Myklebust return 1; 24743cedbf0STrond Myklebust } 24812a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 2491da177e4SLinus Torvalds xprt->snd_task = task; 2501da177e4SLinus Torvalds req->rq_ntrans++; 2511da177e4SLinus Torvalds return 1; 2521da177e4SLinus Torvalds } 253632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2541da177e4SLinus Torvalds out_sleep: 25529807318SNeil Brown if (req) 25629807318SNeil Brown __xprt_put_cong(xprt, req); 25746121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); 2581da177e4SLinus Torvalds task->tk_timeout = 0; 2591da177e4SLinus Torvalds task->tk_status = -EAGAIN; 26034006ceeSTrond Myklebust if (req == NULL) 26134006ceeSTrond Myklebust priority = RPC_PRIORITY_LOW; 26234006ceeSTrond Myklebust else if (!req->rq_ntrans) 26334006ceeSTrond Myklebust priority = RPC_PRIORITY_NORMAL; 2641da177e4SLinus Torvalds else 26534006ceeSTrond Myklebust priority = RPC_PRIORITY_HIGH; 26634006ceeSTrond Myklebust rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); 2671da177e4SLinus Torvalds return 0; 2681da177e4SLinus Torvalds } 26912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); 2701da177e4SLinus Torvalds 27112a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 2721da177e4SLinus Torvalds { 2731da177e4SLinus Torvalds int retval; 2741da177e4SLinus Torvalds 2754a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 27643cedbf0STrond Myklebust retval = xprt->ops->reserve_xprt(xprt, task); 2774a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2781da177e4SLinus Torvalds return retval; 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds 281961a828dSTrond Myklebust static bool __xprt_lock_write_func(struct rpc_task *task, void *data) 2821da177e4SLinus Torvalds { 283961a828dSTrond Myklebust struct rpc_xprt *xprt = data; 28449e9a890SChuck Lever struct rpc_rqst *req; 28549e9a890SChuck Lever 28649e9a890SChuck Lever req = task->tk_rqstp; 28749e9a890SChuck Lever xprt->snd_task = task; 28892551948STrond Myklebust if (req) 28949e9a890SChuck Lever req->rq_ntrans++; 290961a828dSTrond Myklebust return true; 291961a828dSTrond Myklebust } 292961a828dSTrond Myklebust 293961a828dSTrond Myklebust static void __xprt_lock_write_next(struct rpc_xprt *xprt) 294961a828dSTrond Myklebust { 295961a828dSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 29649e9a890SChuck Lever return; 29749e9a890SChuck Lever 298961a828dSTrond Myklebust if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt)) 299961a828dSTrond Myklebust return; 300632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 30149e9a890SChuck Lever } 30249e9a890SChuck Lever 303961a828dSTrond Myklebust static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data) 30449e9a890SChuck Lever { 305961a828dSTrond Myklebust struct rpc_xprt *xprt = data; 30643cedbf0STrond Myklebust struct rpc_rqst *req; 3071da177e4SLinus Torvalds 30843cedbf0STrond Myklebust req = task->tk_rqstp; 30943cedbf0STrond Myklebust if (req == NULL) { 3101da177e4SLinus Torvalds xprt->snd_task = task; 311961a828dSTrond Myklebust return true; 31243cedbf0STrond Myklebust } 31343cedbf0STrond Myklebust if (__xprt_get_cong(xprt, task)) { 31443cedbf0STrond Myklebust xprt->snd_task = task; 3151da177e4SLinus Torvalds req->rq_ntrans++; 316961a828dSTrond Myklebust return true; 3171da177e4SLinus Torvalds } 318961a828dSTrond Myklebust return false; 319961a828dSTrond Myklebust } 320961a828dSTrond Myklebust 321961a828dSTrond Myklebust static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 322961a828dSTrond Myklebust { 323961a828dSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 324961a828dSTrond Myklebust return; 325961a828dSTrond Myklebust if (RPCXPRT_CONGESTED(xprt)) 326961a828dSTrond Myklebust goto out_unlock; 327961a828dSTrond Myklebust if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt)) 328961a828dSTrond Myklebust return; 3291da177e4SLinus Torvalds out_unlock: 330632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3311da177e4SLinus Torvalds } 3321da177e4SLinus Torvalds 3330695314eSTrond Myklebust static void xprt_task_clear_bytes_sent(struct rpc_task *task) 3340695314eSTrond Myklebust { 3350695314eSTrond Myklebust if (task != NULL) { 3360695314eSTrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 3370695314eSTrond Myklebust if (req != NULL) 3380695314eSTrond Myklebust req->rq_bytes_sent = 0; 3390695314eSTrond Myklebust } 3400695314eSTrond Myklebust } 3410695314eSTrond Myklebust 34249e9a890SChuck Lever /** 34349e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 34449e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 34549e9a890SChuck Lever * @task: task that is releasing access to the transport 34649e9a890SChuck Lever * 34749e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 3481da177e4SLinus Torvalds */ 34949e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 3501da177e4SLinus Torvalds { 3511da177e4SLinus Torvalds if (xprt->snd_task == task) { 3520695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 353632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3541da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds } 35712444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt); 3581da177e4SLinus Torvalds 35949e9a890SChuck Lever /** 36049e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 36149e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 36249e9a890SChuck Lever * @task: task that is releasing access to the transport 36349e9a890SChuck Lever * 36449e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 36549e9a890SChuck Lever * transport if the transport's congestion window allows it. 36649e9a890SChuck Lever */ 36749e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 36849e9a890SChuck Lever { 36949e9a890SChuck Lever if (xprt->snd_task == task) { 3700695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 371632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 37249e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 37349e9a890SChuck Lever } 37449e9a890SChuck Lever } 37512444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); 37649e9a890SChuck Lever 37749e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 3781da177e4SLinus Torvalds { 3794a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 38049e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 3814a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 3821da177e4SLinus Torvalds } 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvalds /* 3851da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 3861da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 3871da177e4SLinus Torvalds */ 3881da177e4SLinus Torvalds static int 3891da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 3901da177e4SLinus Torvalds { 3911da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 3921da177e4SLinus Torvalds 3931da177e4SLinus Torvalds if (req->rq_cong) 3941da177e4SLinus Torvalds return 1; 39546121cf7SChuck Lever dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", 3961da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 3971da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 3981da177e4SLinus Torvalds return 0; 3991da177e4SLinus Torvalds req->rq_cong = 1; 4001da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 4011da177e4SLinus Torvalds return 1; 4021da177e4SLinus Torvalds } 4031da177e4SLinus Torvalds 4041da177e4SLinus Torvalds /* 4051da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 4061da177e4SLinus Torvalds * that has been sleeping due to congestion 4071da177e4SLinus Torvalds */ 4081da177e4SLinus Torvalds static void 4091da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 4101da177e4SLinus Torvalds { 4111da177e4SLinus Torvalds if (!req->rq_cong) 4121da177e4SLinus Torvalds return; 4131da177e4SLinus Torvalds req->rq_cong = 0; 4141da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 41549e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4161da177e4SLinus Torvalds } 4171da177e4SLinus Torvalds 41846c0ee8bSChuck Lever /** 419a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 420a58dd398SChuck Lever * @task: RPC request that recently completed 421a58dd398SChuck Lever * 422a58dd398SChuck Lever * Useful for transports that require congestion control. 423a58dd398SChuck Lever */ 424a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 425a58dd398SChuck Lever { 426a4f0835cSTrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 427a4f0835cSTrond Myklebust 428a4f0835cSTrond Myklebust __xprt_put_cong(req->rq_xprt, req); 429a58dd398SChuck Lever } 43012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); 431a58dd398SChuck Lever 432a58dd398SChuck Lever /** 43346c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 4346a24dfb6STrond Myklebust * @xprt: pointer to xprt 43546c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 43646c0ee8bSChuck Lever * @result: result code of completed RPC request 43746c0ee8bSChuck Lever * 4384f4cf5adSChuck Lever * The transport code maintains an estimate on the maximum number of out- 4394f4cf5adSChuck Lever * standing RPC requests, using a smoothed version of the congestion 4404f4cf5adSChuck Lever * avoidance implemented in 44BSD. This is basically the Van Jacobson 4414f4cf5adSChuck Lever * congestion algorithm: If a retransmit occurs, the congestion window is 4424f4cf5adSChuck Lever * halved; otherwise, it is incremented by 1/cwnd when 4434f4cf5adSChuck Lever * 4444f4cf5adSChuck Lever * - a reply is received and 4454f4cf5adSChuck Lever * - a full number of requests are outstanding and 4464f4cf5adSChuck Lever * - the congestion window hasn't been updated recently. 4471da177e4SLinus Torvalds */ 4486a24dfb6STrond Myklebust void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) 4491da177e4SLinus Torvalds { 45046c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 45146c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 4521da177e4SLinus Torvalds 4531da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 4541da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 4551da177e4SLinus Torvalds * the result gets rounded properly. */ 4561da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 4571da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 4581da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 45949e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4601da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 4611da177e4SLinus Torvalds cwnd >>= 1; 4621da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 4631da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 4641da177e4SLinus Torvalds } 4651da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 4661da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 4671da177e4SLinus Torvalds xprt->cwnd = cwnd; 46846c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 4691da177e4SLinus Torvalds } 47012444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); 4711da177e4SLinus Torvalds 47244fbac22SChuck Lever /** 47344fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 47444fbac22SChuck Lever * @xprt: transport with waiting tasks 47544fbac22SChuck Lever * @status: result code to plant in each task before waking it 47644fbac22SChuck Lever * 47744fbac22SChuck Lever */ 47844fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 47944fbac22SChuck Lever { 48044fbac22SChuck Lever if (status < 0) 48144fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 48244fbac22SChuck Lever else 48344fbac22SChuck Lever rpc_wake_up(&xprt->pending); 48444fbac22SChuck Lever } 48512444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); 48644fbac22SChuck Lever 487c7b2cae8SChuck Lever /** 488c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 489c7b2cae8SChuck Lever * @task: task to be put to sleep 4900b80ae42SRandy Dunlap * @action: function pointer to be executed after wait 491a9a6b52eSTrond Myklebust * 492a9a6b52eSTrond Myklebust * Note that we only set the timer for the case of RPC_IS_SOFT(), since 493a9a6b52eSTrond Myklebust * we don't in general want to force a socket disconnection due to 494a9a6b52eSTrond Myklebust * an incomplete RPC call transmission. 495c7b2cae8SChuck Lever */ 496b6ddf64fSTrond Myklebust void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) 497c7b2cae8SChuck Lever { 498c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 499c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 500c7b2cae8SChuck Lever 501a9a6b52eSTrond Myklebust task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0; 502b6ddf64fSTrond Myklebust rpc_sleep_on(&xprt->pending, task, action); 503c7b2cae8SChuck Lever } 50412444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); 505c7b2cae8SChuck Lever 506c7b2cae8SChuck Lever /** 507c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 508c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 509c7b2cae8SChuck Lever * 510c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 511c7b2cae8SChuck Lever */ 512c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 513c7b2cae8SChuck Lever { 514c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 515c7b2cae8SChuck Lever if (xprt->snd_task) { 51646121cf7SChuck Lever dprintk("RPC: write space: waking waiting task on " 51746121cf7SChuck Lever "xprt %p\n", xprt); 518fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); 519c7b2cae8SChuck Lever } 520c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 521c7b2cae8SChuck Lever } 52212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_write_space); 523c7b2cae8SChuck Lever 524fe3aca29SChuck Lever /** 525fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 526fe3aca29SChuck Lever * @task: task whose timeout is to be set 527fe3aca29SChuck Lever * 528fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 529fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 530fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 531fe3aca29SChuck Lever */ 532fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 533fe3aca29SChuck Lever { 534fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 535fe3aca29SChuck Lever } 53612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); 537fe3aca29SChuck Lever 5382c53040fSBen Hutchings /** 539fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 540fe3aca29SChuck Lever * @task: task whose timeout is to be set 541fe3aca29SChuck Lever * 542fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 543fe3aca29SChuck Lever */ 544fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 545fe3aca29SChuck Lever { 546fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 547ba7392bbSTrond Myklebust struct rpc_clnt *clnt = task->tk_client; 548ba7392bbSTrond Myklebust struct rpc_rtt *rtt = clnt->cl_rtt; 549fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 550ba7392bbSTrond Myklebust unsigned long max_timeout = clnt->cl_timeout->to_maxval; 551fe3aca29SChuck Lever 552fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 553fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 554fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 555fe3aca29SChuck Lever task->tk_timeout = max_timeout; 556fe3aca29SChuck Lever } 55712444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); 558fe3aca29SChuck Lever 5591da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 5601da177e4SLinus Torvalds { 561ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5621da177e4SLinus Torvalds 5631da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 5641da177e4SLinus Torvalds if (to->to_exponential) 5651da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 5661da177e4SLinus Torvalds else 5671da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 5681da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 5691da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 5701da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds 5739903cd1cSChuck Lever /** 5749903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 5759903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 5769903cd1cSChuck Lever * 5771da177e4SLinus Torvalds */ 5781da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 5791da177e4SLinus Torvalds { 5801da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 581ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5821da177e4SLinus Torvalds int status = 0; 5831da177e4SLinus Torvalds 5841da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 5851da177e4SLinus Torvalds if (to->to_exponential) 5861da177e4SLinus Torvalds req->rq_timeout <<= 1; 5871da177e4SLinus Torvalds else 5881da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 5891da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 5901da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 5911da177e4SLinus Torvalds req->rq_retries++; 5921da177e4SLinus Torvalds } else { 5931da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 5941da177e4SLinus Torvalds req->rq_retries = 0; 5951da177e4SLinus Torvalds xprt_reset_majortimeo(req); 5961da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 5974a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 5981da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 5994a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 6001da177e4SLinus Torvalds status = -ETIMEDOUT; 6011da177e4SLinus Torvalds } 6021da177e4SLinus Torvalds 6031da177e4SLinus Torvalds if (req->rq_timeout == 0) { 6041da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 6051da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 6061da177e4SLinus Torvalds } 6071da177e4SLinus Torvalds return status; 6081da177e4SLinus Torvalds } 6091da177e4SLinus Torvalds 61065f27f38SDavid Howells static void xprt_autoclose(struct work_struct *work) 6111da177e4SLinus Torvalds { 61265f27f38SDavid Howells struct rpc_xprt *xprt = 61365f27f38SDavid Howells container_of(work, struct rpc_xprt, task_cleanup); 6141da177e4SLinus Torvalds 61566af1e55STrond Myklebust clear_bit(XPRT_CLOSE_WAIT, &xprt->state); 6164876cc77STrond Myklebust xprt->ops->close(xprt); 6171da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 61879234c3dSTrond Myklebust wake_up_bit(&xprt->state, XPRT_LOCKED); 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds 6219903cd1cSChuck Lever /** 62262da3b24STrond Myklebust * xprt_disconnect_done - mark a transport as disconnected 6239903cd1cSChuck Lever * @xprt: transport to flag for disconnect 6249903cd1cSChuck Lever * 6251da177e4SLinus Torvalds */ 62662da3b24STrond Myklebust void xprt_disconnect_done(struct rpc_xprt *xprt) 6271da177e4SLinus Torvalds { 6281da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 6294a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 6301da177e4SLinus Torvalds xprt_clear_connected(xprt); 6312a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 6324a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 6331da177e4SLinus Torvalds } 63462da3b24STrond Myklebust EXPORT_SYMBOL_GPL(xprt_disconnect_done); 6351da177e4SLinus Torvalds 63666af1e55STrond Myklebust /** 63766af1e55STrond Myklebust * xprt_force_disconnect - force a transport to disconnect 63866af1e55STrond Myklebust * @xprt: transport to disconnect 63966af1e55STrond Myklebust * 64066af1e55STrond Myklebust */ 64166af1e55STrond Myklebust void xprt_force_disconnect(struct rpc_xprt *xprt) 64266af1e55STrond Myklebust { 64366af1e55STrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 64466af1e55STrond Myklebust spin_lock_bh(&xprt->transport_lock); 64566af1e55STrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 64666af1e55STrond Myklebust /* Try to schedule an autoclose RPC call */ 64766af1e55STrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 64866af1e55STrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6492a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 65066af1e55STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 65166af1e55STrond Myklebust } 65266af1e55STrond Myklebust 6537c1d71cfSTrond Myklebust /** 6547c1d71cfSTrond Myklebust * xprt_conditional_disconnect - force a transport to disconnect 6557c1d71cfSTrond Myklebust * @xprt: transport to disconnect 6567c1d71cfSTrond Myklebust * @cookie: 'connection cookie' 6577c1d71cfSTrond Myklebust * 6587c1d71cfSTrond Myklebust * This attempts to break the connection if and only if 'cookie' matches 6597c1d71cfSTrond Myklebust * the current transport 'connection cookie'. It ensures that we don't 6607c1d71cfSTrond Myklebust * try to break the connection more than once when we need to retransmit 6617c1d71cfSTrond Myklebust * a batch of RPC requests. 6627c1d71cfSTrond Myklebust * 6637c1d71cfSTrond Myklebust */ 6647c1d71cfSTrond Myklebust void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) 6657c1d71cfSTrond Myklebust { 6667c1d71cfSTrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 6677c1d71cfSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 6687c1d71cfSTrond Myklebust if (cookie != xprt->connect_cookie) 6697c1d71cfSTrond Myklebust goto out; 6707c1d71cfSTrond Myklebust if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) 6717c1d71cfSTrond Myklebust goto out; 6727c1d71cfSTrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 6737c1d71cfSTrond Myklebust /* Try to schedule an autoclose RPC call */ 6747c1d71cfSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 6757c1d71cfSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6762a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 6777c1d71cfSTrond Myklebust out: 6787c1d71cfSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 6797c1d71cfSTrond Myklebust } 6807c1d71cfSTrond Myklebust 6811da177e4SLinus Torvalds static void 6821da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 6831da177e4SLinus Torvalds { 6841da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 6851da177e4SLinus Torvalds 6864a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 687d19751e7STrond Myklebust if (!list_empty(&xprt->recv)) 6881da177e4SLinus Torvalds goto out_abort; 6892226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 6901da177e4SLinus Torvalds goto out_abort; 6914a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 692c1384c9cSTrond Myklebust queue_work(rpciod_workqueue, &xprt->task_cleanup); 6931da177e4SLinus Torvalds return; 6941da177e4SLinus Torvalds out_abort: 6954a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 6961da177e4SLinus Torvalds } 6971da177e4SLinus Torvalds 698718ba5b8STrond Myklebust bool xprt_lock_connect(struct rpc_xprt *xprt, 699718ba5b8STrond Myklebust struct rpc_task *task, 700718ba5b8STrond Myklebust void *cookie) 701718ba5b8STrond Myklebust { 702718ba5b8STrond Myklebust bool ret = false; 703718ba5b8STrond Myklebust 704718ba5b8STrond Myklebust spin_lock_bh(&xprt->transport_lock); 705718ba5b8STrond Myklebust if (!test_bit(XPRT_LOCKED, &xprt->state)) 706718ba5b8STrond Myklebust goto out; 707718ba5b8STrond Myklebust if (xprt->snd_task != task) 708718ba5b8STrond Myklebust goto out; 7090695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 710718ba5b8STrond Myklebust xprt->snd_task = cookie; 711718ba5b8STrond Myklebust ret = true; 712718ba5b8STrond Myklebust out: 713718ba5b8STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 714718ba5b8STrond Myklebust return ret; 715718ba5b8STrond Myklebust } 716718ba5b8STrond Myklebust 717718ba5b8STrond Myklebust void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) 718718ba5b8STrond Myklebust { 719718ba5b8STrond Myklebust spin_lock_bh(&xprt->transport_lock); 720718ba5b8STrond Myklebust if (xprt->snd_task != cookie) 721718ba5b8STrond Myklebust goto out; 722718ba5b8STrond Myklebust if (!test_bit(XPRT_LOCKED, &xprt->state)) 723718ba5b8STrond Myklebust goto out; 724718ba5b8STrond Myklebust xprt->snd_task =NULL; 725718ba5b8STrond Myklebust xprt->ops->release_xprt(xprt, NULL); 726718ba5b8STrond Myklebust out: 727718ba5b8STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 72879234c3dSTrond Myklebust wake_up_bit(&xprt->state, XPRT_LOCKED); 729718ba5b8STrond Myklebust } 730718ba5b8STrond Myklebust 7319903cd1cSChuck Lever /** 7329903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 7339903cd1cSChuck Lever * @task: RPC task that is requesting the connect 7341da177e4SLinus Torvalds * 7351da177e4SLinus Torvalds */ 7361da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 7371da177e4SLinus Torvalds { 738ad2368d6STrond Myklebust struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 7391da177e4SLinus Torvalds 74046121cf7SChuck Lever dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, 7411da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 7421da177e4SLinus Torvalds 743ec739ef0SChuck Lever if (!xprt_bound(xprt)) { 74401d37c42STrond Myklebust task->tk_status = -EAGAIN; 7451da177e4SLinus Torvalds return; 7461da177e4SLinus Torvalds } 7471da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 7481da177e4SLinus Torvalds return; 749feb8ca37STrond Myklebust 750feb8ca37STrond Myklebust if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) 751feb8ca37STrond Myklebust xprt->ops->close(xprt); 752feb8ca37STrond Myklebust 753718ba5b8STrond Myklebust if (!xprt_connected(xprt)) { 7541da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 755a8ce4a8fSTrond Myklebust task->tk_timeout = task->tk_rqstp->rq_timeout; 7565d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_connect_status); 7570b9e7943STrond Myklebust 7580b9e7943STrond Myklebust if (test_bit(XPRT_CLOSING, &xprt->state)) 7590b9e7943STrond Myklebust return; 7600b9e7943STrond Myklebust if (xprt_test_and_set_connecting(xprt)) 7610b9e7943STrond Myklebust return; 762262ca07dSChuck Lever xprt->stat.connect_start = jiffies; 7631b092092STrond Myklebust xprt->ops->connect(xprt, task); 7641da177e4SLinus Torvalds } 765718ba5b8STrond Myklebust xprt_release_write(xprt, task); 7661da177e4SLinus Torvalds } 7671da177e4SLinus Torvalds 7689903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 7691da177e4SLinus Torvalds { 770ad2368d6STrond Myklebust struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 7711da177e4SLinus Torvalds 772cd983ef8SChuck Lever if (task->tk_status == 0) { 773262ca07dSChuck Lever xprt->stat.connect_count++; 774262ca07dSChuck Lever xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; 77546121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection established\n", 7761da177e4SLinus Torvalds task->tk_pid); 7771da177e4SLinus Torvalds return; 7781da177e4SLinus Torvalds } 7791da177e4SLinus Torvalds 7801da177e4SLinus Torvalds switch (task->tk_status) { 7810fe8d04eSTrond Myklebust case -ECONNREFUSED: 7820fe8d04eSTrond Myklebust case -ECONNRESET: 7830fe8d04eSTrond Myklebust case -ECONNABORTED: 7840fe8d04eSTrond Myklebust case -ENETUNREACH: 7850fe8d04eSTrond Myklebust case -EHOSTUNREACH: 7862fc193cfSTrond Myklebust case -EPIPE: 7872a491991STrond Myklebust case -EAGAIN: 7882a491991STrond Myklebust dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); 78923475d66SChuck Lever break; 7901da177e4SLinus Torvalds case -ETIMEDOUT: 79146121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connect attempt timed " 79246121cf7SChuck Lever "out\n", task->tk_pid); 7931da177e4SLinus Torvalds break; 7941da177e4SLinus Torvalds default: 79546121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: error %d connecting to " 79646121cf7SChuck Lever "server %s\n", task->tk_pid, -task->tk_status, 7974e0038b6STrond Myklebust xprt->servername); 79823475d66SChuck Lever task->tk_status = -EIO; 79923475d66SChuck Lever } 8001da177e4SLinus Torvalds } 8011da177e4SLinus Torvalds 8029903cd1cSChuck Lever /** 8039903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 8049903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 8059903cd1cSChuck Lever * @xid: RPC XID of incoming reply 8069903cd1cSChuck Lever * 8071da177e4SLinus Torvalds */ 808d8ed029dSAlexey Dobriyan struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) 8091da177e4SLinus Torvalds { 8108f3a6de3SPavel Emelyanov struct rpc_rqst *entry; 8111da177e4SLinus Torvalds 8128f3a6de3SPavel Emelyanov list_for_each_entry(entry, &xprt->recv, rq_list) 8133705ad64SJeff Layton if (entry->rq_xid == xid) { 8143705ad64SJeff Layton trace_xprt_lookup_rqst(xprt, xid, 0); 815262ca07dSChuck Lever return entry; 8163705ad64SJeff Layton } 81746121cf7SChuck Lever 81846121cf7SChuck Lever dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", 81946121cf7SChuck Lever ntohl(xid)); 8203705ad64SJeff Layton trace_xprt_lookup_rqst(xprt, xid, -ENOENT); 821262ca07dSChuck Lever xprt->stat.bad_xids++; 822262ca07dSChuck Lever return NULL; 8231da177e4SLinus Torvalds } 82412444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_lookup_rqst); 8251da177e4SLinus Torvalds 826bbc72ceaSChuck Lever static void xprt_update_rtt(struct rpc_task *task) 8271da177e4SLinus Torvalds { 8281570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 8291570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 83095c96174SEric Dumazet unsigned int timer = task->tk_msg.rpc_proc->p_timer; 831d60dbb20STrond Myklebust long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); 8321570c1e4SChuck Lever 8331da177e4SLinus Torvalds if (timer) { 8341da177e4SLinus Torvalds if (req->rq_ntrans == 1) 835ff839970SChuck Lever rpc_update_rtt(rtt, timer, m); 8361570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 8371da177e4SLinus Torvalds } 8381da177e4SLinus Torvalds } 8391da177e4SLinus Torvalds 8401570c1e4SChuck Lever /** 8411570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 8421570c1e4SChuck Lever * @task: RPC request that recently completed 8431570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 8441570c1e4SChuck Lever * 8451570c1e4SChuck Lever * Caller holds transport lock. 8461570c1e4SChuck Lever */ 8471570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 8481570c1e4SChuck Lever { 8491570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 850fda13939STrond Myklebust struct rpc_xprt *xprt = req->rq_xprt; 8511da177e4SLinus Torvalds 8521570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 8531570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 8543705ad64SJeff Layton trace_xprt_complete_rqst(xprt, req->rq_xid, copied); 8551da177e4SLinus Torvalds 856fda13939STrond Myklebust xprt->stat.recvs++; 857d60dbb20STrond Myklebust req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); 858bbc72ceaSChuck Lever if (xprt->ops->timer != NULL) 859bbc72ceaSChuck Lever xprt_update_rtt(task); 860ef759a2eSChuck Lever 8611da177e4SLinus Torvalds list_del_init(&req->rq_list); 8621e799b67STrond Myklebust req->rq_private_buf.len = copied; 863dd2b63d0SRicardo Labiaga /* Ensure all writes are done before we update */ 864dd2b63d0SRicardo Labiaga /* req->rq_reply_bytes_recvd */ 86543ac3f29STrond Myklebust smp_wmb(); 866dd2b63d0SRicardo Labiaga req->rq_reply_bytes_recvd = copied; 867fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, task); 8681da177e4SLinus Torvalds } 86912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_complete_rqst); 8701da177e4SLinus Torvalds 87146c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 8721da177e4SLinus Torvalds { 8731da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8741da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 8751da177e4SLinus Torvalds 8765d00837bSTrond Myklebust if (task->tk_status != -ETIMEDOUT) 8775d00837bSTrond Myklebust return; 87846121cf7SChuck Lever dprintk("RPC: %5u xprt_timer\n", task->tk_pid); 87946c0ee8bSChuck Lever 8805d00837bSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 881dd2b63d0SRicardo Labiaga if (!req->rq_reply_bytes_recvd) { 88246c0ee8bSChuck Lever if (xprt->ops->timer) 8836a24dfb6STrond Myklebust xprt->ops->timer(xprt, task); 8845d00837bSTrond Myklebust } else 8855d00837bSTrond Myklebust task->tk_status = 0; 8865d00837bSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 8871da177e4SLinus Torvalds } 8881da177e4SLinus Torvalds 8894cfc7e60SRahul Iyer static inline int xprt_has_timer(struct rpc_xprt *xprt) 8904cfc7e60SRahul Iyer { 8914cfc7e60SRahul Iyer return xprt->idle_timeout != 0; 8924cfc7e60SRahul Iyer } 8934cfc7e60SRahul Iyer 8949903cd1cSChuck Lever /** 8959903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 8969903cd1cSChuck Lever * @task: RPC task about to send a request 8979903cd1cSChuck Lever * 8981da177e4SLinus Torvalds */ 89990051ea7STrond Myklebust bool xprt_prepare_transmit(struct rpc_task *task) 9001da177e4SLinus Torvalds { 9011da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9021da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 90390051ea7STrond Myklebust bool ret = false; 9041da177e4SLinus Torvalds 90546121cf7SChuck Lever dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); 9061da177e4SLinus Torvalds 9074a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 9088a19a0b6STrond Myklebust if (!req->rq_bytes_sent) { 9098a19a0b6STrond Myklebust if (req->rq_reply_bytes_recvd) { 91090051ea7STrond Myklebust task->tk_status = req->rq_reply_bytes_recvd; 9111da177e4SLinus Torvalds goto out_unlock; 9121da177e4SLinus Torvalds } 9138a19a0b6STrond Myklebust if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) 9148a19a0b6STrond Myklebust && xprt_connected(xprt) 9158a19a0b6STrond Myklebust && req->rq_connect_cookie == xprt->connect_cookie) { 9168a19a0b6STrond Myklebust xprt->ops->set_retrans_timeout(task); 9178a19a0b6STrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_timer); 9188a19a0b6STrond Myklebust goto out_unlock; 9198a19a0b6STrond Myklebust } 9208a19a0b6STrond Myklebust } 92190051ea7STrond Myklebust if (!xprt->ops->reserve_xprt(xprt, task)) { 92290051ea7STrond Myklebust task->tk_status = -EAGAIN; 92390051ea7STrond Myklebust goto out_unlock; 92490051ea7STrond Myklebust } 92590051ea7STrond Myklebust ret = true; 9261da177e4SLinus Torvalds out_unlock: 9274a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 92890051ea7STrond Myklebust return ret; 9291da177e4SLinus Torvalds } 9301da177e4SLinus Torvalds 931e0ab53deSTrond Myklebust void xprt_end_transmit(struct rpc_task *task) 9325e5ce5beSTrond Myklebust { 933343952faSRahul Iyer xprt_release_write(task->tk_rqstp->rq_xprt, task); 9345e5ce5beSTrond Myklebust } 9355e5ce5beSTrond Myklebust 9369903cd1cSChuck Lever /** 9379903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 9389903cd1cSChuck Lever * @task: controlling RPC task 9399903cd1cSChuck Lever * 9409903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 9419903cd1cSChuck Lever */ 9429903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 9431da177e4SLinus Torvalds { 9441da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9451da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 94615a45206SAndy Adamson int status, numreqs; 9471da177e4SLinus Torvalds 94846121cf7SChuck Lever dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 9491da177e4SLinus Torvalds 950dd2b63d0SRicardo Labiaga if (!req->rq_reply_bytes_recvd) { 95155ae1aabSRicardo Labiaga if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { 95255ae1aabSRicardo Labiaga /* 95355ae1aabSRicardo Labiaga * Add to the list only if we're expecting a reply 95455ae1aabSRicardo Labiaga */ 9554a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 9561da177e4SLinus Torvalds /* Update the softirq receive buffer */ 9571da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 9581da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 9591da177e4SLinus Torvalds /* Add request to the receive list */ 9601da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 9614a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 9621da177e4SLinus Torvalds xprt_reset_majortimeo(req); 9630f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 9640f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 9651da177e4SLinus Torvalds } 9661da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 9671da177e4SLinus Torvalds return; 9681da177e4SLinus Torvalds 969ff839970SChuck Lever req->rq_xtime = ktime_get(); 970a246b010SChuck Lever status = xprt->ops->send_request(task); 9713705ad64SJeff Layton trace_xprt_transmit(xprt, req->rq_xid, status); 972c8485e4dSTrond Myklebust if (status != 0) { 973c8485e4dSTrond Myklebust task->tk_status = status; 974c8485e4dSTrond Myklebust return; 975c8485e4dSTrond Myklebust } 9764a068258SChuck Lever xprt_inject_disconnect(xprt); 977c8485e4dSTrond Myklebust 97846121cf7SChuck Lever dprintk("RPC: %5u xmit complete\n", task->tk_pid); 979468f8613SBryan Schumaker task->tk_flags |= RPC_TASK_SENT; 980fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 981262ca07dSChuck Lever 982fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 983262ca07dSChuck Lever 98415a45206SAndy Adamson numreqs = atomic_read(&xprt->num_reqs); 98515a45206SAndy Adamson if (numreqs > xprt->stat.max_slots) 98615a45206SAndy Adamson xprt->stat.max_slots = numreqs; 987262ca07dSChuck Lever xprt->stat.sends++; 988262ca07dSChuck Lever xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; 989262ca07dSChuck Lever xprt->stat.bklog_u += xprt->backlog.qlen; 99015a45206SAndy Adamson xprt->stat.sending_u += xprt->sending.qlen; 99115a45206SAndy Adamson xprt->stat.pending_u += xprt->pending.qlen; 992262ca07dSChuck Lever 993fe3aca29SChuck Lever /* Don't race with disconnect */ 994fe3aca29SChuck Lever if (!xprt_connected(xprt)) 995fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 9960a660521STrond Myklebust else { 99755ae1aabSRicardo Labiaga /* 99855ae1aabSRicardo Labiaga * Sleep on the pending queue since 99955ae1aabSRicardo Labiaga * we're expecting a reply. 100055ae1aabSRicardo Labiaga */ 10010a660521STrond Myklebust if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) 10025d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_timer); 10030a660521STrond Myklebust req->rq_connect_cookie = xprt->connect_cookie; 100455ae1aabSRicardo Labiaga } 1005fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 10061da177e4SLinus Torvalds } 10071da177e4SLinus Torvalds 1008ba60eb25STrond Myklebust static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) 1009ba60eb25STrond Myklebust { 1010ba60eb25STrond Myklebust set_bit(XPRT_CONGESTED, &xprt->state); 1011ba60eb25STrond Myklebust rpc_sleep_on(&xprt->backlog, task, NULL); 1012ba60eb25STrond Myklebust } 1013ba60eb25STrond Myklebust 1014ba60eb25STrond Myklebust static void xprt_wake_up_backlog(struct rpc_xprt *xprt) 1015ba60eb25STrond Myklebust { 1016ba60eb25STrond Myklebust if (rpc_wake_up_next(&xprt->backlog) == NULL) 1017ba60eb25STrond Myklebust clear_bit(XPRT_CONGESTED, &xprt->state); 1018ba60eb25STrond Myklebust } 1019ba60eb25STrond Myklebust 1020ba60eb25STrond Myklebust static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) 1021ba60eb25STrond Myklebust { 1022ba60eb25STrond Myklebust bool ret = false; 1023ba60eb25STrond Myklebust 1024ba60eb25STrond Myklebust if (!test_bit(XPRT_CONGESTED, &xprt->state)) 1025ba60eb25STrond Myklebust goto out; 1026ba60eb25STrond Myklebust spin_lock(&xprt->reserve_lock); 1027ba60eb25STrond Myklebust if (test_bit(XPRT_CONGESTED, &xprt->state)) { 1028ba60eb25STrond Myklebust rpc_sleep_on(&xprt->backlog, task, NULL); 1029ba60eb25STrond Myklebust ret = true; 1030ba60eb25STrond Myklebust } 1031ba60eb25STrond Myklebust spin_unlock(&xprt->reserve_lock); 1032ba60eb25STrond Myklebust out: 1033ba60eb25STrond Myklebust return ret; 1034ba60eb25STrond Myklebust } 1035ba60eb25STrond Myklebust 1036d9ba131dSTrond Myklebust static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) 1037d9ba131dSTrond Myklebust { 1038d9ba131dSTrond Myklebust struct rpc_rqst *req = ERR_PTR(-EAGAIN); 1039d9ba131dSTrond Myklebust 1040d9ba131dSTrond Myklebust if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) 1041d9ba131dSTrond Myklebust goto out; 1042d9ba131dSTrond Myklebust req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); 1043d9ba131dSTrond Myklebust if (req != NULL) 1044d9ba131dSTrond Myklebust goto out; 1045d9ba131dSTrond Myklebust atomic_dec(&xprt->num_reqs); 1046d9ba131dSTrond Myklebust req = ERR_PTR(-ENOMEM); 1047d9ba131dSTrond Myklebust out: 1048d9ba131dSTrond Myklebust return req; 1049d9ba131dSTrond Myklebust } 1050d9ba131dSTrond Myklebust 1051d9ba131dSTrond Myklebust static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) 1052d9ba131dSTrond Myklebust { 1053d9ba131dSTrond Myklebust if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { 1054d9ba131dSTrond Myklebust kfree(req); 1055d9ba131dSTrond Myklebust return true; 1056d9ba131dSTrond Myklebust } 1057d9ba131dSTrond Myklebust return false; 1058d9ba131dSTrond Myklebust } 1059d9ba131dSTrond Myklebust 1060f39c1bfbSTrond Myklebust void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) 10611da177e4SLinus Torvalds { 1062d9ba131dSTrond Myklebust struct rpc_rqst *req; 10631da177e4SLinus Torvalds 1064f39c1bfbSTrond Myklebust spin_lock(&xprt->reserve_lock); 10651da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 1066d9ba131dSTrond Myklebust req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 1067d9ba131dSTrond Myklebust list_del(&req->rq_list); 1068d9ba131dSTrond Myklebust goto out_init_req; 1069d9ba131dSTrond Myklebust } 10706b343099SJeff Layton req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN); 1071d9ba131dSTrond Myklebust if (!IS_ERR(req)) 1072d9ba131dSTrond Myklebust goto out_init_req; 1073d9ba131dSTrond Myklebust switch (PTR_ERR(req)) { 1074d9ba131dSTrond Myklebust case -ENOMEM: 1075d9ba131dSTrond Myklebust dprintk("RPC: dynamic allocation of request slot " 1076d9ba131dSTrond Myklebust "failed! Retrying\n"); 10771afeaf5cSTrond Myklebust task->tk_status = -ENOMEM; 1078d9ba131dSTrond Myklebust break; 1079d9ba131dSTrond Myklebust case -EAGAIN: 1080ba60eb25STrond Myklebust xprt_add_backlog(xprt, task); 1081d9ba131dSTrond Myklebust dprintk("RPC: waiting for request slot\n"); 10821afeaf5cSTrond Myklebust default: 1083d9ba131dSTrond Myklebust task->tk_status = -EAGAIN; 10841afeaf5cSTrond Myklebust } 1085f39c1bfbSTrond Myklebust spin_unlock(&xprt->reserve_lock); 1086d9ba131dSTrond Myklebust return; 1087d9ba131dSTrond Myklebust out_init_req: 1088d9ba131dSTrond Myklebust task->tk_status = 0; 10891da177e4SLinus Torvalds task->tk_rqstp = req; 10901da177e4SLinus Torvalds xprt_request_init(task, xprt); 1091f39c1bfbSTrond Myklebust spin_unlock(&xprt->reserve_lock); 10921da177e4SLinus Torvalds } 1093f39c1bfbSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_alloc_slot); 1094f39c1bfbSTrond Myklebust 1095f39c1bfbSTrond Myklebust void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) 1096f39c1bfbSTrond Myklebust { 1097f39c1bfbSTrond Myklebust /* Note: grabbing the xprt_lock_write() ensures that we throttle 1098f39c1bfbSTrond Myklebust * new slot allocation if the transport is congested (i.e. when 1099f39c1bfbSTrond Myklebust * reconnecting a stream transport or when out of socket write 1100f39c1bfbSTrond Myklebust * buffer space). 1101f39c1bfbSTrond Myklebust */ 1102f39c1bfbSTrond Myklebust if (xprt_lock_write(xprt, task)) { 1103f39c1bfbSTrond Myklebust xprt_alloc_slot(xprt, task); 1104f39c1bfbSTrond Myklebust xprt_release_write(xprt, task); 1105f39c1bfbSTrond Myklebust } 1106f39c1bfbSTrond Myklebust } 1107f39c1bfbSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot); 11081da177e4SLinus Torvalds 1109ee5ebe85STrond Myklebust static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) 1110ee5ebe85STrond Myklebust { 1111ee5ebe85STrond Myklebust spin_lock(&xprt->reserve_lock); 1112c25573b5STrond Myklebust if (!xprt_dynamic_free_slot(xprt, req)) { 1113c25573b5STrond Myklebust memset(req, 0, sizeof(*req)); /* mark unused */ 1114ee5ebe85STrond Myklebust list_add(&req->rq_list, &xprt->free); 1115c25573b5STrond Myklebust } 1116ba60eb25STrond Myklebust xprt_wake_up_backlog(xprt); 1117ee5ebe85STrond Myklebust spin_unlock(&xprt->reserve_lock); 1118ee5ebe85STrond Myklebust } 1119ee5ebe85STrond Myklebust 112021de0a95STrond Myklebust static void xprt_free_all_slots(struct rpc_xprt *xprt) 112121de0a95STrond Myklebust { 112221de0a95STrond Myklebust struct rpc_rqst *req; 112321de0a95STrond Myklebust while (!list_empty(&xprt->free)) { 112421de0a95STrond Myklebust req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); 112521de0a95STrond Myklebust list_del(&req->rq_list); 112621de0a95STrond Myklebust kfree(req); 112721de0a95STrond Myklebust } 112821de0a95STrond Myklebust } 112921de0a95STrond Myklebust 1130d9ba131dSTrond Myklebust struct rpc_xprt *xprt_alloc(struct net *net, size_t size, 1131d9ba131dSTrond Myklebust unsigned int num_prealloc, 1132d9ba131dSTrond Myklebust unsigned int max_alloc) 1133bd1722d4SPavel Emelyanov { 1134bd1722d4SPavel Emelyanov struct rpc_xprt *xprt; 113521de0a95STrond Myklebust struct rpc_rqst *req; 113621de0a95STrond Myklebust int i; 1137bd1722d4SPavel Emelyanov 1138bd1722d4SPavel Emelyanov xprt = kzalloc(size, GFP_KERNEL); 1139bd1722d4SPavel Emelyanov if (xprt == NULL) 1140bd1722d4SPavel Emelyanov goto out; 1141bd1722d4SPavel Emelyanov 114221de0a95STrond Myklebust xprt_init(xprt, net); 114321de0a95STrond Myklebust 114421de0a95STrond Myklebust for (i = 0; i < num_prealloc; i++) { 114521de0a95STrond Myklebust req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); 114621de0a95STrond Myklebust if (!req) 11478313164cSwangweidong goto out_free; 114821de0a95STrond Myklebust list_add(&req->rq_list, &xprt->free); 114921de0a95STrond Myklebust } 1150d9ba131dSTrond Myklebust if (max_alloc > num_prealloc) 1151d9ba131dSTrond Myklebust xprt->max_reqs = max_alloc; 1152d9ba131dSTrond Myklebust else 115321de0a95STrond Myklebust xprt->max_reqs = num_prealloc; 1154d9ba131dSTrond Myklebust xprt->min_reqs = num_prealloc; 1155d9ba131dSTrond Myklebust atomic_set(&xprt->num_reqs, num_prealloc); 1156bd1722d4SPavel Emelyanov 1157bd1722d4SPavel Emelyanov return xprt; 1158bd1722d4SPavel Emelyanov 1159bd1722d4SPavel Emelyanov out_free: 116021de0a95STrond Myklebust xprt_free(xprt); 1161bd1722d4SPavel Emelyanov out: 1162bd1722d4SPavel Emelyanov return NULL; 1163bd1722d4SPavel Emelyanov } 1164bd1722d4SPavel Emelyanov EXPORT_SYMBOL_GPL(xprt_alloc); 1165bd1722d4SPavel Emelyanov 1166e204e621SPavel Emelyanov void xprt_free(struct rpc_xprt *xprt) 1167e204e621SPavel Emelyanov { 116837aa2133SPavel Emelyanov put_net(xprt->xprt_net); 116921de0a95STrond Myklebust xprt_free_all_slots(xprt); 1170fda1bfefSTrond Myklebust kfree_rcu(xprt, rcu); 1171e204e621SPavel Emelyanov } 1172e204e621SPavel Emelyanov EXPORT_SYMBOL_GPL(xprt_free); 1173e204e621SPavel Emelyanov 11749903cd1cSChuck Lever /** 11759903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 11769903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 11779903cd1cSChuck Lever * 1178ba60eb25STrond Myklebust * If the transport is marked as being congested, or if no more 1179ba60eb25STrond Myklebust * slots are available, place the task on the transport's 11809903cd1cSChuck Lever * backlog queue. 11819903cd1cSChuck Lever */ 11829903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 11831da177e4SLinus Torvalds { 118445bc0dceSTrond Myklebust struct rpc_xprt *xprt; 11851da177e4SLinus Torvalds 118643cedbf0STrond Myklebust task->tk_status = 0; 118743cedbf0STrond Myklebust if (task->tk_rqstp != NULL) 118843cedbf0STrond Myklebust return; 118943cedbf0STrond Myklebust 119043cedbf0STrond Myklebust task->tk_timeout = 0; 119143cedbf0STrond Myklebust task->tk_status = -EAGAIN; 119245bc0dceSTrond Myklebust rcu_read_lock(); 119345bc0dceSTrond Myklebust xprt = rcu_dereference(task->tk_client->cl_xprt); 1194ba60eb25STrond Myklebust if (!xprt_throttle_congested(xprt, task)) 1195ba60eb25STrond Myklebust xprt->ops->alloc_slot(xprt, task); 1196ba60eb25STrond Myklebust rcu_read_unlock(); 1197ba60eb25STrond Myklebust } 1198ba60eb25STrond Myklebust 1199ba60eb25STrond Myklebust /** 1200ba60eb25STrond Myklebust * xprt_retry_reserve - allocate an RPC request slot 1201ba60eb25STrond Myklebust * @task: RPC task requesting a slot allocation 1202ba60eb25STrond Myklebust * 1203ba60eb25STrond Myklebust * If no more slots are available, place the task on the transport's 1204ba60eb25STrond Myklebust * backlog queue. 1205ba60eb25STrond Myklebust * Note that the only difference with xprt_reserve is that we now 1206ba60eb25STrond Myklebust * ignore the value of the XPRT_CONGESTED flag. 1207ba60eb25STrond Myklebust */ 1208ba60eb25STrond Myklebust void xprt_retry_reserve(struct rpc_task *task) 1209ba60eb25STrond Myklebust { 1210ba60eb25STrond Myklebust struct rpc_xprt *xprt; 1211ba60eb25STrond Myklebust 1212ba60eb25STrond Myklebust task->tk_status = 0; 1213ba60eb25STrond Myklebust if (task->tk_rqstp != NULL) 1214ba60eb25STrond Myklebust return; 1215ba60eb25STrond Myklebust 1216ba60eb25STrond Myklebust task->tk_timeout = 0; 1217ba60eb25STrond Myklebust task->tk_status = -EAGAIN; 1218ba60eb25STrond Myklebust rcu_read_lock(); 1219ba60eb25STrond Myklebust xprt = rcu_dereference(task->tk_client->cl_xprt); 1220f39c1bfbSTrond Myklebust xprt->ops->alloc_slot(xprt, task); 122145bc0dceSTrond Myklebust rcu_read_unlock(); 12221da177e4SLinus Torvalds } 12231da177e4SLinus Torvalds 1224d8ed029dSAlexey Dobriyan static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) 12251da177e4SLinus Torvalds { 12260eae88f3SEric Dumazet return (__force __be32)xprt->xid++; 12271da177e4SLinus Torvalds } 12281da177e4SLinus Torvalds 12291da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 12301da177e4SLinus Torvalds { 123163862b5bSAruna-Hewapathirane xprt->xid = prandom_u32(); 12321da177e4SLinus Torvalds } 12331da177e4SLinus Torvalds 12349903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 12351da177e4SLinus Torvalds { 12361da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 12371da177e4SLinus Torvalds 1238d9ba131dSTrond Myklebust INIT_LIST_HEAD(&req->rq_list); 1239ba7392bbSTrond Myklebust req->rq_timeout = task->tk_client->cl_timeout->to_initval; 12401da177e4SLinus Torvalds req->rq_task = task; 12411da177e4SLinus Torvalds req->rq_xprt = xprt; 124202107148SChuck Lever req->rq_buffer = NULL; 12431da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 12440a660521STrond Myklebust req->rq_connect_cookie = xprt->connect_cookie - 1; 124592551948STrond Myklebust req->rq_bytes_sent = 0; 124692551948STrond Myklebust req->rq_snd_buf.len = 0; 124792551948STrond Myklebust req->rq_snd_buf.buflen = 0; 124892551948STrond Myklebust req->rq_rcv_buf.len = 0; 124992551948STrond Myklebust req->rq_rcv_buf.buflen = 0; 1250ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf = NULL; 1251da45828eSTrond Myklebust xprt_reset_majortimeo(req); 125246121cf7SChuck Lever dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, 12531da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 12541da177e4SLinus Torvalds } 12551da177e4SLinus Torvalds 12569903cd1cSChuck Lever /** 12579903cd1cSChuck Lever * xprt_release - release an RPC request slot 12589903cd1cSChuck Lever * @task: task which is finished with the slot 12599903cd1cSChuck Lever * 12601da177e4SLinus Torvalds */ 12619903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 12621da177e4SLinus Torvalds { 126355ae1aabSRicardo Labiaga struct rpc_xprt *xprt; 126487ed5003STrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 12651da177e4SLinus Torvalds 126687ed5003STrond Myklebust if (req == NULL) { 126787ed5003STrond Myklebust if (task->tk_client) { 126887ed5003STrond Myklebust rcu_read_lock(); 126987ed5003STrond Myklebust xprt = rcu_dereference(task->tk_client->cl_xprt); 127087ed5003STrond Myklebust if (xprt->snd_task == task) 127187ed5003STrond Myklebust xprt_release_write(xprt, task); 127287ed5003STrond Myklebust rcu_read_unlock(); 127387ed5003STrond Myklebust } 12741da177e4SLinus Torvalds return; 127587ed5003STrond Myklebust } 127655ae1aabSRicardo Labiaga 127755ae1aabSRicardo Labiaga xprt = req->rq_xprt; 12780a702195SWeston Andros Adamson if (task->tk_ops->rpc_count_stats != NULL) 12790a702195SWeston Andros Adamson task->tk_ops->rpc_count_stats(task, task->tk_calldata); 12800a702195SWeston Andros Adamson else if (task->tk_client) 12810a702195SWeston Andros Adamson rpc_count_iostats(task, task->tk_client->cl_metrics); 12824a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 128349e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 1284a58dd398SChuck Lever if (xprt->ops->release_request) 1285a58dd398SChuck Lever xprt->ops->release_request(task); 12861da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 12871da177e4SLinus Torvalds list_del(&req->rq_list); 12881da177e4SLinus Torvalds xprt->last_used = jiffies; 12894cfc7e60SRahul Iyer if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) 1290a246b010SChuck Lever mod_timer(&xprt->timer, 129103bf4b70SChuck Lever xprt->last_used + xprt->idle_timeout); 12924a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 1293ee5ebe85STrond Myklebust if (req->rq_buffer) 1294c5a4dd8bSChuck Lever xprt->ops->buf_free(req->rq_buffer); 12954a068258SChuck Lever xprt_inject_disconnect(xprt); 1296a17c2153STrond Myklebust if (req->rq_cred != NULL) 1297a17c2153STrond Myklebust put_rpccred(req->rq_cred); 12981da177e4SLinus Torvalds task->tk_rqstp = NULL; 1299ead5e1c2SJ. Bruce Fields if (req->rq_release_snd_buf) 1300ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf(req); 130155ae1aabSRicardo Labiaga 130246121cf7SChuck Lever dprintk("RPC: %5u release request %p\n", task->tk_pid, req); 1303ee5ebe85STrond Myklebust if (likely(!bc_prealloc(req))) 1304ee5ebe85STrond Myklebust xprt_free_slot(xprt, req); 1305ee5ebe85STrond Myklebust else 1306c9acb42eSTrond Myklebust xprt_free_bc_request(req); 13071da177e4SLinus Torvalds } 13081da177e4SLinus Torvalds 130921de0a95STrond Myklebust static void xprt_init(struct rpc_xprt *xprt, struct net *net) 1310c2866763SChuck Lever { 131130c5116bSTrond Myklebust kref_init(&xprt->kref); 1312c2866763SChuck Lever 1313c2866763SChuck Lever spin_lock_init(&xprt->transport_lock); 1314c2866763SChuck Lever spin_lock_init(&xprt->reserve_lock); 1315c2866763SChuck Lever 1316c2866763SChuck Lever INIT_LIST_HEAD(&xprt->free); 1317c2866763SChuck Lever INIT_LIST_HEAD(&xprt->recv); 13189e00abc3STrond Myklebust #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1319f9acac1aSRicardo Labiaga spin_lock_init(&xprt->bc_pa_lock); 1320f9acac1aSRicardo Labiaga INIT_LIST_HEAD(&xprt->bc_pa_list); 13219e00abc3STrond Myklebust #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 132280b14d5eSTrond Myklebust INIT_LIST_HEAD(&xprt->xprt_switch); 1323f9acac1aSRicardo Labiaga 1324c2866763SChuck Lever xprt->last_used = jiffies; 1325c2866763SChuck Lever xprt->cwnd = RPC_INITCWND; 1326a509050bSChuck Lever xprt->bind_index = 0; 1327c2866763SChuck Lever 1328c2866763SChuck Lever rpc_init_wait_queue(&xprt->binding, "xprt_binding"); 1329c2866763SChuck Lever rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 133034006ceeSTrond Myklebust rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); 1331c2866763SChuck Lever rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 1332c2866763SChuck Lever 1333c2866763SChuck Lever xprt_init_xid(xprt); 1334c2866763SChuck Lever 133521de0a95STrond Myklebust xprt->xprt_net = get_net(net); 13368d9266ffSTrond Myklebust } 13378d9266ffSTrond Myklebust 13388d9266ffSTrond Myklebust /** 13398d9266ffSTrond Myklebust * xprt_create_transport - create an RPC transport 13408d9266ffSTrond Myklebust * @args: rpc transport creation arguments 13418d9266ffSTrond Myklebust * 13428d9266ffSTrond Myklebust */ 13438d9266ffSTrond Myklebust struct rpc_xprt *xprt_create_transport(struct xprt_create *args) 13448d9266ffSTrond Myklebust { 13458d9266ffSTrond Myklebust struct rpc_xprt *xprt; 13468d9266ffSTrond Myklebust struct xprt_class *t; 13478d9266ffSTrond Myklebust 13488d9266ffSTrond Myklebust spin_lock(&xprt_list_lock); 13498d9266ffSTrond Myklebust list_for_each_entry(t, &xprt_list, list) { 13508d9266ffSTrond Myklebust if (t->ident == args->ident) { 13518d9266ffSTrond Myklebust spin_unlock(&xprt_list_lock); 13528d9266ffSTrond Myklebust goto found; 13538d9266ffSTrond Myklebust } 13548d9266ffSTrond Myklebust } 13558d9266ffSTrond Myklebust spin_unlock(&xprt_list_lock); 13563c45ddf8SChuck Lever dprintk("RPC: transport (%d) not supported\n", args->ident); 13578d9266ffSTrond Myklebust return ERR_PTR(-EIO); 13588d9266ffSTrond Myklebust 13598d9266ffSTrond Myklebust found: 13608d9266ffSTrond Myklebust xprt = t->setup(args); 13618d9266ffSTrond Myklebust if (IS_ERR(xprt)) { 13628d9266ffSTrond Myklebust dprintk("RPC: xprt_create_transport: failed, %ld\n", 13638d9266ffSTrond Myklebust -PTR_ERR(xprt)); 136421de0a95STrond Myklebust goto out; 13658d9266ffSTrond Myklebust } 136633d90ac0SJ. Bruce Fields if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT) 136733d90ac0SJ. Bruce Fields xprt->idle_timeout = 0; 136821de0a95STrond Myklebust INIT_WORK(&xprt->task_cleanup, xprt_autoclose); 136921de0a95STrond Myklebust if (xprt_has_timer(xprt)) 137021de0a95STrond Myklebust setup_timer(&xprt->timer, xprt_init_autodisconnect, 137121de0a95STrond Myklebust (unsigned long)xprt); 137221de0a95STrond Myklebust else 137321de0a95STrond Myklebust init_timer(&xprt->timer); 13744e0038b6STrond Myklebust 13754e0038b6STrond Myklebust if (strlen(args->servername) > RPC_MAXNETNAMELEN) { 13764e0038b6STrond Myklebust xprt_destroy(xprt); 13774e0038b6STrond Myklebust return ERR_PTR(-EINVAL); 13784e0038b6STrond Myklebust } 13794e0038b6STrond Myklebust xprt->servername = kstrdup(args->servername, GFP_KERNEL); 13804e0038b6STrond Myklebust if (xprt->servername == NULL) { 13814e0038b6STrond Myklebust xprt_destroy(xprt); 13824e0038b6STrond Myklebust return ERR_PTR(-ENOMEM); 13834e0038b6STrond Myklebust } 13844e0038b6STrond Myklebust 13853f940098SJeff Layton rpc_xprt_debugfs_register(xprt); 1386388f0c77SJeff Layton 1387c2866763SChuck Lever dprintk("RPC: created transport %p with %u slots\n", xprt, 1388c2866763SChuck Lever xprt->max_reqs); 138921de0a95STrond Myklebust out: 1390c2866763SChuck Lever return xprt; 1391c2866763SChuck Lever } 1392c2866763SChuck Lever 13939903cd1cSChuck Lever /** 13949903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 1395a8de240aSTrond Myklebust * @xprt: transport to destroy 13969903cd1cSChuck Lever * 13971da177e4SLinus Torvalds */ 1398a8de240aSTrond Myklebust static void xprt_destroy(struct rpc_xprt *xprt) 13991da177e4SLinus Torvalds { 14001da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 140179234c3dSTrond Myklebust 140279234c3dSTrond Myklebust /* Exclude transport connect/disconnect handlers */ 140379234c3dSTrond Myklebust wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); 140479234c3dSTrond Myklebust 14050065db32STrond Myklebust del_timer_sync(&xprt->timer); 1406c8541ecdSChuck Lever 1407388f0c77SJeff Layton rpc_xprt_debugfs_unregister(xprt); 1408f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->binding); 1409f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->pending); 1410f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->sending); 1411f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->backlog); 1412c3ae62aeSJ. Bruce Fields cancel_work_sync(&xprt->task_cleanup); 14134e0038b6STrond Myklebust kfree(xprt->servername); 1414c8541ecdSChuck Lever /* 1415c8541ecdSChuck Lever * Tear down transport state and free the rpc_xprt 1416c8541ecdSChuck Lever */ 1417a246b010SChuck Lever xprt->ops->destroy(xprt); 14186b6ca86bSTrond Myklebust } 14191da177e4SLinus Torvalds 142030c5116bSTrond Myklebust static void xprt_destroy_kref(struct kref *kref) 142130c5116bSTrond Myklebust { 142230c5116bSTrond Myklebust xprt_destroy(container_of(kref, struct rpc_xprt, kref)); 142330c5116bSTrond Myklebust } 142430c5116bSTrond Myklebust 142530c5116bSTrond Myklebust /** 142630c5116bSTrond Myklebust * xprt_get - return a reference to an RPC transport. 142730c5116bSTrond Myklebust * @xprt: pointer to the transport 142830c5116bSTrond Myklebust * 142930c5116bSTrond Myklebust */ 143030c5116bSTrond Myklebust struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) 143130c5116bSTrond Myklebust { 143230c5116bSTrond Myklebust if (xprt != NULL && kref_get_unless_zero(&xprt->kref)) 143330c5116bSTrond Myklebust return xprt; 143430c5116bSTrond Myklebust return NULL; 143530c5116bSTrond Myklebust } 143630c5116bSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_get); 143730c5116bSTrond Myklebust 14386b6ca86bSTrond Myklebust /** 14396b6ca86bSTrond Myklebust * xprt_put - release a reference to an RPC transport. 14406b6ca86bSTrond Myklebust * @xprt: pointer to the transport 14416b6ca86bSTrond Myklebust * 14426b6ca86bSTrond Myklebust */ 14436b6ca86bSTrond Myklebust void xprt_put(struct rpc_xprt *xprt) 14446b6ca86bSTrond Myklebust { 144530c5116bSTrond Myklebust if (xprt != NULL) 144630c5116bSTrond Myklebust kref_put(&xprt->kref, xprt_destroy_kref); 14476b6ca86bSTrond Myklebust } 14485d252f90SChuck Lever EXPORT_SYMBOL_GPL(xprt_put); 1449