blob: 2d1d5a643b950c42b068b97f8f8db9cf5d14ce19 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/net/sunrpc/xprt.c
3 *
4 * This is a generic RPC call interface supporting congestion avoidance,
5 * and asynchronous calls.
6 *
7 * The interface works like this:
8 *
9 * - When a process places a call, it allocates a request slot if
10 * one is available. Otherwise, it sleeps on the backlog queue
11 * (xprt_reserve).
12 * - Next, the caller puts together the RPC message, stuffs it into
Chuck Lever55aa4f52005-08-11 16:25:47 -040013 * the request struct, and calls xprt_transmit().
14 * - xprt_transmit sends the message and installs the caller on the
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -040015 * transport's wait list. At the same time, if a reply is expected,
16 * it installs a timer that is run after the packet's timeout has
17 * expired.
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * - When a packet arrives, the data_ready handler walks the list of
Chuck Lever55aa4f52005-08-11 16:25:47 -040019 * pending requests for that transport. If a matching XID is found, the
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 * caller is woken up, and the timer removed.
21 * - When no reply arrives within the timeout interval, the timer is
22 * fired by the kernel and runs xprt_timer(). It either adjusts the
23 * timeout values (minor timeout) or wakes up the caller with a status
24 * of -ETIMEDOUT.
25 * - When the caller receives a notification from RPC that a reply arrived,
26 * it should release the RPC slot, and process the reply.
27 * If the call timed out, it may choose to retry the operation by
28 * adjusting the initial timeout value, and simply calling rpc_call
29 * again.
30 *
31 * Support for async RPC is done through a set of RPC-specific scheduling
32 * primitives that `transparently' work for processes as well as async
33 * tasks that rely on callbacks.
34 *
35 * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
Chuck Lever55aa4f52005-08-11 16:25:47 -040036 *
37 * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 */
39
Chuck Levera246b012005-08-11 16:25:23 -040040#include <linux/module.h>
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <linux/types.h>
Chuck Levera246b012005-08-11 16:25:23 -040043#include <linux/interrupt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/workqueue.h>
Chuck Leverbf3fcf82006-05-25 01:40:51 -040045#include <linux/net.h>
Chuck Leverff839972010-05-07 13:34:47 -040046#include <linux/ktime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Chuck Levera246b012005-08-11 16:25:23 -040048#include <linux/sunrpc/clnt.h>
Chuck Lever11c556b2006-03-20 13:44:22 -050049#include <linux/sunrpc/metrics.h>
Trond Myklebustc9acb422010-03-19 15:36:22 -040050#include <linux/sunrpc/bc_xprt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -040052#include "sunrpc.h"
53
Linus Torvalds1da177e2005-04-16 15:20:36 -070054/*
55 * Local variables
56 */
57
58#ifdef RPC_DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070059# define RPCDBG_FACILITY RPCDBG_XPRT
60#endif
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062/*
63 * Local functions
64 */
Trond Myklebust21de0a92011-07-17 16:57:32 -040065static void xprt_init(struct rpc_xprt *xprt, struct net *net);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067static void xprt_connect_status(struct rpc_task *task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
Trond Myklebust4e0038b2012-03-01 17:01:05 -050069static void xprt_destroy(struct rpc_xprt *xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Jiri Slaby5ba03e82007-11-22 19:40:22 +080071static DEFINE_SPINLOCK(xprt_list_lock);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040072static LIST_HEAD(xprt_list);
73
Chuck Lever12a80462005-08-25 16:25:51 -070074/**
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040075 * xprt_register_transport - register a transport implementation
76 * @transport: transport to register
77 *
78 * If a transport implementation is loaded as a kernel module, it can
79 * call this interface to make itself known to the RPC client.
80 *
81 * Returns:
82 * 0: transport successfully registered
83 * -EEXIST: transport already registered
84 * -EINVAL: transport module being unloaded
85 */
86int xprt_register_transport(struct xprt_class *transport)
87{
88 struct xprt_class *t;
89 int result;
90
91 result = -EEXIST;
92 spin_lock(&xprt_list_lock);
93 list_for_each_entry(t, &xprt_list, list) {
94 /* don't register the same transport class twice */
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -040095 if (t->ident == transport->ident)
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040096 goto out;
97 }
98
Denis V. Lunevc9f6cde2008-07-31 09:53:56 +040099 list_add_tail(&transport->list, &xprt_list);
100 printk(KERN_INFO "RPC: Registered %s transport module.\n",
101 transport->name);
102 result = 0;
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400103
104out:
105 spin_unlock(&xprt_list_lock);
106 return result;
107}
108EXPORT_SYMBOL_GPL(xprt_register_transport);
109
110/**
111 * xprt_unregister_transport - unregister a transport implementation
Randy Dunlap65b6e422008-02-13 15:03:23 -0800112 * @transport: transport to unregister
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400113 *
114 * Returns:
115 * 0: transport successfully unregistered
116 * -ENOENT: transport never registered
117 */
118int xprt_unregister_transport(struct xprt_class *transport)
119{
120 struct xprt_class *t;
121 int result;
122
123 result = 0;
124 spin_lock(&xprt_list_lock);
125 list_for_each_entry(t, &xprt_list, list) {
126 if (t == transport) {
127 printk(KERN_INFO
128 "RPC: Unregistered %s transport module.\n",
129 transport->name);
130 list_del_init(&transport->list);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400131 goto out;
132 }
133 }
134 result = -ENOENT;
135
136out:
137 spin_unlock(&xprt_list_lock);
138 return result;
139}
140EXPORT_SYMBOL_GPL(xprt_unregister_transport);
141
142/**
Tom Talpey441e3e22009-03-11 14:37:56 -0400143 * xprt_load_transport - load a transport implementation
144 * @transport_name: transport to load
145 *
146 * Returns:
147 * 0: transport successfully loaded
148 * -ENOENT: transport module not available
149 */
150int xprt_load_transport(const char *transport_name)
151{
152 struct xprt_class *t;
Tom Talpey441e3e22009-03-11 14:37:56 -0400153 int result;
154
155 result = 0;
156 spin_lock(&xprt_list_lock);
157 list_for_each_entry(t, &xprt_list, list) {
158 if (strcmp(t->name, transport_name) == 0) {
159 spin_unlock(&xprt_list_lock);
160 goto out;
161 }
162 }
163 spin_unlock(&xprt_list_lock);
Alex Riesenef7ffe82010-05-24 14:33:05 -0700164 result = request_module("xprt%s", transport_name);
Tom Talpey441e3e22009-03-11 14:37:56 -0400165out:
166 return result;
167}
168EXPORT_SYMBOL_GPL(xprt_load_transport);
169
170/**
Chuck Lever12a80462005-08-25 16:25:51 -0700171 * xprt_reserve_xprt - serialize write access to transports
172 * @task: task that is requesting access to the transport
Randy Dunlap177c27b2011-07-28 06:54:36 +0000173 * @xprt: pointer to the target transport
Chuck Lever12a80462005-08-25 16:25:51 -0700174 *
175 * This prevents mixing the payload of separate requests, and prevents
176 * transport connects from colliding with writes. No congestion control
177 * is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400179int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Chuck Lever12a80462005-08-25 16:25:51 -0700181 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400182 int priority;
Chuck Lever12a80462005-08-25 16:25:51 -0700183
184 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
185 if (task == xprt->snd_task)
186 return 1;
Chuck Lever12a80462005-08-25 16:25:51 -0700187 goto out_sleep;
188 }
189 xprt->snd_task = task;
Trond Myklebust92551942013-09-27 11:28:40 -0400190 if (req != NULL)
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400191 req->rq_ntrans++;
j223yang@asset.uwaterloo.ca4d4a76f2011-03-10 12:40:28 -0500192
Chuck Lever12a80462005-08-25 16:25:51 -0700193 return 1;
194
195out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500196 dprintk("RPC: %5u failed to lock transport %p\n",
Chuck Lever12a80462005-08-25 16:25:51 -0700197 task->tk_pid, xprt);
198 task->tk_timeout = 0;
199 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400200 if (req == NULL)
201 priority = RPC_PRIORITY_LOW;
202 else if (!req->rq_ntrans)
203 priority = RPC_PRIORITY_NORMAL;
Chuck Lever12a80462005-08-25 16:25:51 -0700204 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400205 priority = RPC_PRIORITY_HIGH;
206 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Chuck Lever12a80462005-08-25 16:25:51 -0700207 return 0;
208}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400209EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
Chuck Lever12a80462005-08-25 16:25:51 -0700210
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100211static void xprt_clear_locked(struct rpc_xprt *xprt)
212{
213 xprt->snd_task = NULL;
Trond Myklebustd19751e2012-09-11 17:21:25 -0400214 if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100215 smp_mb__before_clear_bit();
216 clear_bit(XPRT_LOCKED, &xprt->state);
217 smp_mb__after_clear_bit();
218 } else
Trond Myklebustc1384c92007-06-14 18:00:42 -0400219 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100220}
221
Chuck Lever12a80462005-08-25 16:25:51 -0700222/*
223 * xprt_reserve_xprt_cong - serialize write access to transports
224 * @task: task that is requesting access to the transport
225 *
226 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
227 * integrated into the decision of whether a request is allowed to be
228 * woken up and given access to the transport.
229 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400230int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
Chuck Lever12a80462005-08-25 16:25:51 -0700231{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400233 int priority;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Chuck Lever2226feb2005-08-11 16:25:38 -0400235 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 if (task == xprt->snd_task)
237 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 goto out_sleep;
239 }
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400240 if (req == NULL) {
241 xprt->snd_task = task;
242 return 1;
243 }
Chuck Lever12a80462005-08-25 16:25:51 -0700244 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400246 req->rq_ntrans++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 return 1;
248 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100249 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500251 dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 task->tk_timeout = 0;
253 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400254 if (req == NULL)
255 priority = RPC_PRIORITY_LOW;
256 else if (!req->rq_ntrans)
257 priority = RPC_PRIORITY_NORMAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400259 priority = RPC_PRIORITY_HIGH;
260 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 return 0;
262}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400263EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Chuck Lever12a80462005-08-25 16:25:51 -0700265static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
267 int retval;
268
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400269 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400270 retval = xprt->ops->reserve_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400271 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 return retval;
273}
274
Trond Myklebust961a8282012-01-17 22:57:37 -0500275static bool __xprt_lock_write_func(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Trond Myklebust961a8282012-01-17 22:57:37 -0500277 struct rpc_xprt *xprt = data;
Chuck Lever49e9a892005-08-25 16:25:51 -0700278 struct rpc_rqst *req;
279
Chuck Lever49e9a892005-08-25 16:25:51 -0700280 req = task->tk_rqstp;
281 xprt->snd_task = task;
Trond Myklebust92551942013-09-27 11:28:40 -0400282 if (req)
Chuck Lever49e9a892005-08-25 16:25:51 -0700283 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500284 return true;
285}
Chuck Lever49e9a892005-08-25 16:25:51 -0700286
Trond Myklebust961a8282012-01-17 22:57:37 -0500287static void __xprt_lock_write_next(struct rpc_xprt *xprt)
288{
289 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
290 return;
291
292 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt))
293 return;
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100294 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700295}
296
Trond Myklebust961a8282012-01-17 22:57:37 -0500297static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data)
Chuck Lever49e9a892005-08-25 16:25:51 -0700298{
Trond Myklebust961a8282012-01-17 22:57:37 -0500299 struct rpc_xprt *xprt = data;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400300 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400302 req = task->tk_rqstp;
303 if (req == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 xprt->snd_task = task;
Trond Myklebust961a8282012-01-17 22:57:37 -0500305 return true;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400306 }
307 if (__xprt_get_cong(xprt, task)) {
308 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400309 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500310 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 }
Trond Myklebust961a8282012-01-17 22:57:37 -0500312 return false;
313}
314
315static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
316{
317 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
318 return;
319 if (RPCXPRT_CONGESTED(xprt))
320 goto out_unlock;
321 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt))
322 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100324 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325}
326
Chuck Lever49e9a892005-08-25 16:25:51 -0700327/**
328 * xprt_release_xprt - allow other requests to use a transport
329 * @xprt: transport with other tasks potentially waiting
330 * @task: task that is releasing access to the transport
331 *
332 * Note that "task" can be NULL. No congestion control is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 */
Chuck Lever49e9a892005-08-25 16:25:51 -0700334void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335{
336 if (xprt->snd_task == task) {
Trond Myklebustee071ef2013-09-27 11:09:53 -0400337 if (task != NULL) {
338 struct rpc_rqst *req = task->tk_rqstp;
339 if (req != NULL)
340 req->rq_bytes_sent = 0;
341 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100342 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 __xprt_lock_write_next(xprt);
344 }
345}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400346EXPORT_SYMBOL_GPL(xprt_release_xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Chuck Lever49e9a892005-08-25 16:25:51 -0700348/**
349 * xprt_release_xprt_cong - allow other requests to use a transport
350 * @xprt: transport with other tasks potentially waiting
351 * @task: task that is releasing access to the transport
352 *
353 * Note that "task" can be NULL. Another task is awoken to use the
354 * transport if the transport's congestion window allows it.
355 */
356void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
357{
358 if (xprt->snd_task == task) {
Trond Myklebustee071ef2013-09-27 11:09:53 -0400359 if (task != NULL) {
360 struct rpc_rqst *req = task->tk_rqstp;
361 if (req != NULL)
362 req->rq_bytes_sent = 0;
363 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100364 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700365 __xprt_lock_write_next_cong(xprt);
366 }
367}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400368EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
Chuck Lever49e9a892005-08-25 16:25:51 -0700369
370static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400372 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -0700373 xprt->ops->release_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400374 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375}
376
377/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 * Van Jacobson congestion avoidance. Check if the congestion window
379 * overflowed. Put the task to sleep if this is the case.
380 */
381static int
382__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
383{
384 struct rpc_rqst *req = task->tk_rqstp;
385
386 if (req->rq_cong)
387 return 1;
Chuck Lever46121cf2007-01-31 12:14:08 -0500388 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 task->tk_pid, xprt->cong, xprt->cwnd);
390 if (RPCXPRT_CONGESTED(xprt))
391 return 0;
392 req->rq_cong = 1;
393 xprt->cong += RPC_CWNDSCALE;
394 return 1;
395}
396
397/*
398 * Adjust the congestion window, and wake up the next task
399 * that has been sleeping due to congestion
400 */
401static void
402__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
403{
404 if (!req->rq_cong)
405 return;
406 req->rq_cong = 0;
407 xprt->cong -= RPC_CWNDSCALE;
Chuck Lever49e9a892005-08-25 16:25:51 -0700408 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409}
410
Chuck Lever46c0ee82005-08-25 16:25:52 -0700411/**
Chuck Levera58dd392005-08-25 16:25:53 -0700412 * xprt_release_rqst_cong - housekeeping when request is complete
413 * @task: RPC request that recently completed
414 *
415 * Useful for transports that require congestion control.
416 */
417void xprt_release_rqst_cong(struct rpc_task *task)
418{
Trond Myklebusta4f08352013-01-08 09:10:21 -0500419 struct rpc_rqst *req = task->tk_rqstp;
420
421 __xprt_put_cong(req->rq_xprt, req);
Chuck Levera58dd392005-08-25 16:25:53 -0700422}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400423EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
Chuck Levera58dd392005-08-25 16:25:53 -0700424
425/**
Chuck Lever46c0ee82005-08-25 16:25:52 -0700426 * xprt_adjust_cwnd - adjust transport congestion window
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500427 * @xprt: pointer to xprt
Chuck Lever46c0ee82005-08-25 16:25:52 -0700428 * @task: recently completed RPC request used to adjust window
429 * @result: result code of completed RPC request
430 *
Chuck Lever4f4cf5a2014-05-28 10:34:49 -0400431 * The transport code maintains an estimate on the maximum number of out-
432 * standing RPC requests, using a smoothed version of the congestion
433 * avoidance implemented in 44BSD. This is basically the Van Jacobson
434 * congestion algorithm: If a retransmit occurs, the congestion window is
435 * halved; otherwise, it is incremented by 1/cwnd when
436 *
437 * - a reply is received and
438 * - a full number of requests are outstanding and
439 * - the congestion window hasn't been updated recently.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 */
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500441void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700443 struct rpc_rqst *req = task->tk_rqstp;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700444 unsigned long cwnd = xprt->cwnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 if (result >= 0 && cwnd <= xprt->cong) {
447 /* The (cwnd >> 1) term makes sure
448 * the result gets rounded properly. */
449 cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
450 if (cwnd > RPC_MAXCWND(xprt))
451 cwnd = RPC_MAXCWND(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700452 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 } else if (result == -ETIMEDOUT) {
454 cwnd >>= 1;
455 if (cwnd < RPC_CWNDSCALE)
456 cwnd = RPC_CWNDSCALE;
457 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500458 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 xprt->cong, xprt->cwnd, cwnd);
460 xprt->cwnd = cwnd;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700461 __xprt_put_cong(xprt, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400463EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
Chuck Lever44fbac22005-08-11 16:25:44 -0400465/**
466 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
467 * @xprt: transport with waiting tasks
468 * @status: result code to plant in each task before waking it
469 *
470 */
471void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
472{
473 if (status < 0)
474 rpc_wake_up_status(&xprt->pending, status);
475 else
476 rpc_wake_up(&xprt->pending);
477}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400478EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
Chuck Lever44fbac22005-08-11 16:25:44 -0400479
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400480/**
481 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
482 * @task: task to be put to sleep
Randy Dunlap0b80ae42008-04-26 22:59:02 -0700483 * @action: function pointer to be executed after wait
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500484 *
485 * Note that we only set the timer for the case of RPC_IS_SOFT(), since
486 * we don't in general want to force a socket disconnection due to
487 * an incomplete RPC call transmission.
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400488 */
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400489void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400490{
491 struct rpc_rqst *req = task->tk_rqstp;
492 struct rpc_xprt *xprt = req->rq_xprt;
493
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500494 task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0;
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400495 rpc_sleep_on(&xprt->pending, task, action);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400496}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400497EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400498
499/**
500 * xprt_write_space - wake the task waiting for transport output buffer space
501 * @xprt: transport with waiting tasks
502 *
503 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
504 */
505void xprt_write_space(struct rpc_xprt *xprt)
506{
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400507 spin_lock_bh(&xprt->transport_lock);
508 if (xprt->snd_task) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500509 dprintk("RPC: write space: waking waiting task on "
510 "xprt %p\n", xprt);
Trond Myklebustfda13932008-02-22 16:34:12 -0500511 rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400512 }
513 spin_unlock_bh(&xprt->transport_lock);
514}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400515EXPORT_SYMBOL_GPL(xprt_write_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400516
Chuck Leverfe3aca22005-08-25 16:25:50 -0700517/**
518 * xprt_set_retrans_timeout_def - set a request's retransmit timeout
519 * @task: task whose timeout is to be set
520 *
521 * Set a request's retransmit timeout based on the transport's
522 * default timeout parameters. Used by transports that don't adjust
523 * the retransmit timeout based on round-trip time estimation.
524 */
525void xprt_set_retrans_timeout_def(struct rpc_task *task)
526{
527 task->tk_timeout = task->tk_rqstp->rq_timeout;
528}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400529EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700530
Ben Hutchings2c530402012-07-10 10:55:09 +0000531/**
Chuck Leverfe3aca22005-08-25 16:25:50 -0700532 * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
533 * @task: task whose timeout is to be set
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800534 *
Chuck Leverfe3aca22005-08-25 16:25:50 -0700535 * Set a request's retransmit timeout using the RTT estimator.
536 */
537void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
538{
539 int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500540 struct rpc_clnt *clnt = task->tk_client;
541 struct rpc_rtt *rtt = clnt->cl_rtt;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700542 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500543 unsigned long max_timeout = clnt->cl_timeout->to_maxval;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700544
545 task->tk_timeout = rpc_calc_rto(rtt, timer);
546 task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
547 if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
548 task->tk_timeout = max_timeout;
549}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400550EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700551
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552static void xprt_reset_majortimeo(struct rpc_rqst *req)
553{
Trond Myklebustba7392b2007-12-20 16:03:55 -0500554 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
556 req->rq_majortimeo = req->rq_timeout;
557 if (to->to_exponential)
558 req->rq_majortimeo <<= to->to_retries;
559 else
560 req->rq_majortimeo += to->to_increment * to->to_retries;
561 if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
562 req->rq_majortimeo = to->to_maxval;
563 req->rq_majortimeo += jiffies;
564}
565
Chuck Lever9903cd12005-08-11 16:25:26 -0400566/**
567 * xprt_adjust_timeout - adjust timeout values for next retransmit
568 * @req: RPC request containing parameters to use for the adjustment
569 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 */
571int xprt_adjust_timeout(struct rpc_rqst *req)
572{
573 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500574 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 int status = 0;
576
577 if (time_before(jiffies, req->rq_majortimeo)) {
578 if (to->to_exponential)
579 req->rq_timeout <<= 1;
580 else
581 req->rq_timeout += to->to_increment;
582 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
583 req->rq_timeout = to->to_maxval;
584 req->rq_retries++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 } else {
586 req->rq_timeout = to->to_initval;
587 req->rq_retries = 0;
588 xprt_reset_majortimeo(req);
589 /* Reset the RTT counters == "slow start" */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400590 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400592 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 status = -ETIMEDOUT;
594 }
595
596 if (req->rq_timeout == 0) {
597 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
598 req->rq_timeout = 5 * HZ;
599 }
600 return status;
601}
602
David Howells65f27f32006-11-22 14:55:48 +0000603static void xprt_autoclose(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
David Howells65f27f32006-11-22 14:55:48 +0000605 struct rpc_xprt *xprt =
606 container_of(work, struct rpc_xprt, task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
Chuck Levera246b012005-08-11 16:25:23 -0400608 xprt->ops->close(xprt);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500609 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 xprt_release_write(xprt, NULL);
611}
612
Chuck Lever9903cd12005-08-11 16:25:26 -0400613/**
Trond Myklebust62da3b22007-11-06 18:44:20 -0500614 * xprt_disconnect_done - mark a transport as disconnected
Chuck Lever9903cd12005-08-11 16:25:26 -0400615 * @xprt: transport to flag for disconnect
616 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 */
Trond Myklebust62da3b22007-11-06 18:44:20 -0500618void xprt_disconnect_done(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619{
Chuck Lever46121cf2007-01-31 12:14:08 -0500620 dprintk("RPC: disconnected transport %p\n", xprt);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400621 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 xprt_clear_connected(xprt);
Trond Myklebust2a491992009-03-11 14:38:00 -0400623 xprt_wake_pending_tasks(xprt, -EAGAIN);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400624 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625}
Trond Myklebust62da3b22007-11-06 18:44:20 -0500626EXPORT_SYMBOL_GPL(xprt_disconnect_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Trond Myklebust66af1e52007-11-06 10:18:36 -0500628/**
629 * xprt_force_disconnect - force a transport to disconnect
630 * @xprt: transport to disconnect
631 *
632 */
633void xprt_force_disconnect(struct rpc_xprt *xprt)
634{
635 /* Don't race with the test_bit() in xprt_clear_locked() */
636 spin_lock_bh(&xprt->transport_lock);
637 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
638 /* Try to schedule an autoclose RPC call */
639 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
640 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400641 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500642 spin_unlock_bh(&xprt->transport_lock);
643}
Trond Myklebust66af1e52007-11-06 10:18:36 -0500644
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400645/**
646 * xprt_conditional_disconnect - force a transport to disconnect
647 * @xprt: transport to disconnect
648 * @cookie: 'connection cookie'
649 *
650 * This attempts to break the connection if and only if 'cookie' matches
651 * the current transport 'connection cookie'. It ensures that we don't
652 * try to break the connection more than once when we need to retransmit
653 * a batch of RPC requests.
654 *
655 */
656void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
657{
658 /* Don't race with the test_bit() in xprt_clear_locked() */
659 spin_lock_bh(&xprt->transport_lock);
660 if (cookie != xprt->connect_cookie)
661 goto out;
662 if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
663 goto out;
664 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
665 /* Try to schedule an autoclose RPC call */
666 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
667 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400668 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400669out:
670 spin_unlock_bh(&xprt->transport_lock);
671}
672
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673static void
674xprt_init_autodisconnect(unsigned long data)
675{
676 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
677
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400678 spin_lock(&xprt->transport_lock);
Trond Myklebustd19751e2012-09-11 17:21:25 -0400679 if (!list_empty(&xprt->recv))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 goto out_abort;
Chuck Lever2226feb2005-08-11 16:25:38 -0400681 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 goto out_abort;
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400683 spin_unlock(&xprt->transport_lock);
Trond Myklebustf75e6742009-04-21 17:18:20 -0400684 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
685 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 return;
687out_abort:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400688 spin_unlock(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689}
690
Chuck Lever9903cd12005-08-11 16:25:26 -0400691/**
692 * xprt_connect - schedule a transport connect operation
693 * @task: RPC task that is requesting the connect
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 *
695 */
696void xprt_connect(struct rpc_task *task)
697{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500698 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Chuck Lever46121cf2007-01-31 12:14:08 -0500700 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 xprt, (xprt_connected(xprt) ? "is" : "is not"));
702
Chuck Leverec739ef2006-08-22 20:06:15 -0400703 if (!xprt_bound(xprt)) {
Trond Myklebust01d37c42009-03-11 14:09:39 -0400704 task->tk_status = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 return;
706 }
707 if (!xprt_lock_write(xprt, task))
708 return;
Trond Myklebustfeb8ca32009-12-03 08:10:17 -0500709
710 if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
711 xprt->ops->close(xprt);
712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (xprt_connected(xprt))
Chuck Levera246b012005-08-11 16:25:23 -0400714 xprt_release_write(xprt, task);
715 else {
Dan Carpenter87e3c052012-02-01 10:46:20 +0300716 task->tk_rqstp->rq_bytes_sent = 0;
Trond Myklebusta8ce4a82010-04-16 16:42:12 -0400717 task->tk_timeout = task->tk_rqstp->rq_timeout;
Trond Myklebust5d008372008-02-22 16:34:17 -0500718 rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
Trond Myklebust0b9e7942010-04-16 16:41:57 -0400719
720 if (test_bit(XPRT_CLOSING, &xprt->state))
721 return;
722 if (xprt_test_and_set_connecting(xprt))
723 return;
Chuck Lever262ca072006-03-20 13:44:16 -0500724 xprt->stat.connect_start = jiffies;
Trond Myklebust1b092092013-01-08 09:26:49 -0500725 xprt->ops->connect(xprt, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727}
728
Chuck Lever9903cd12005-08-11 16:25:26 -0400729static void xprt_connect_status(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500731 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
Chuck Levercd983ef2008-06-11 17:56:13 -0400733 if (task->tk_status == 0) {
Chuck Lever262ca072006-03-20 13:44:16 -0500734 xprt->stat.connect_count++;
735 xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
Chuck Lever46121cf2007-01-31 12:14:08 -0500736 dprintk("RPC: %5u xprt_connect_status: connection established\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 task->tk_pid);
738 return;
739 }
740
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 switch (task->tk_status) {
Trond Myklebust0fe8d042013-12-31 13:13:30 -0500742 case -ECONNREFUSED:
743 case -ECONNRESET:
744 case -ECONNABORTED:
745 case -ENETUNREACH:
746 case -EHOSTUNREACH:
Trond Myklebust2a491992009-03-11 14:38:00 -0400747 case -EAGAIN:
748 dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
Chuck Lever23475d62005-08-11 16:25:08 -0400749 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 case -ETIMEDOUT:
Chuck Lever46121cf2007-01-31 12:14:08 -0500751 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
752 "out\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 break;
754 default:
Chuck Lever46121cf2007-01-31 12:14:08 -0500755 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
756 "server %s\n", task->tk_pid, -task->tk_status,
Trond Myklebust4e0038b2012-03-01 17:01:05 -0500757 xprt->servername);
Chuck Lever23475d62005-08-11 16:25:08 -0400758 xprt_release_write(xprt, task);
759 task->tk_status = -EIO;
Chuck Lever23475d62005-08-11 16:25:08 -0400760 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761}
762
Chuck Lever9903cd12005-08-11 16:25:26 -0400763/**
764 * xprt_lookup_rqst - find an RPC request corresponding to an XID
765 * @xprt: transport on which the original request was transmitted
766 * @xid: RPC XID of incoming reply
767 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700769struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770{
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400771 struct rpc_rqst *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400773 list_for_each_entry(entry, &xprt->recv, rq_list)
Chuck Lever262ca072006-03-20 13:44:16 -0500774 if (entry->rq_xid == xid)
775 return entry;
Chuck Lever46121cf2007-01-31 12:14:08 -0500776
777 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
778 ntohl(xid));
Chuck Lever262ca072006-03-20 13:44:16 -0500779 xprt->stat.bad_xids++;
780 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400782EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400784static void xprt_update_rtt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785{
Chuck Lever1570c1e2005-08-25 16:25:52 -0700786 struct rpc_rqst *req = task->tk_rqstp;
787 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
Eric Dumazet95c96172012-04-15 05:58:06 +0000788 unsigned int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400789 long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Chuck Lever1570c1e2005-08-25 16:25:52 -0700791 if (timer) {
792 if (req->rq_ntrans == 1)
Chuck Leverff839972010-05-07 13:34:47 -0400793 rpc_update_rtt(rtt, timer, m);
Chuck Lever1570c1e2005-08-25 16:25:52 -0700794 rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 }
Chuck Lever1570c1e2005-08-25 16:25:52 -0700796}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
Chuck Lever1570c1e2005-08-25 16:25:52 -0700798/**
799 * xprt_complete_rqst - called when reply processing is complete
800 * @task: RPC request that recently completed
801 * @copied: actual number of bytes received from the transport
802 *
803 * Caller holds transport lock.
804 */
805void xprt_complete_rqst(struct rpc_task *task, int copied)
806{
807 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustfda13932008-02-22 16:34:12 -0500808 struct rpc_xprt *xprt = req->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809
Chuck Lever1570c1e2005-08-25 16:25:52 -0700810 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
811 task->tk_pid, ntohl(req->rq_xid), copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
Trond Myklebustfda13932008-02-22 16:34:12 -0500813 xprt->stat.recvs++;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400814 req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime);
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400815 if (xprt->ops->timer != NULL)
816 xprt_update_rtt(task);
Chuck Leveref759a22006-03-20 13:44:17 -0500817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 list_del_init(&req->rq_list);
Trond Myklebust1e799b62008-03-21 16:19:41 -0400819 req->rq_private_buf.len = copied;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400820 /* Ensure all writes are done before we update */
821 /* req->rq_reply_bytes_recvd */
Trond Myklebust43ac3f22006-03-20 13:44:51 -0500822 smp_wmb();
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400823 req->rq_reply_bytes_recvd = copied;
Trond Myklebustfda13932008-02-22 16:34:12 -0500824 rpc_wake_up_queued_task(&xprt->pending, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400826EXPORT_SYMBOL_GPL(xprt_complete_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827
Chuck Lever46c0ee82005-08-25 16:25:52 -0700828static void xprt_timer(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700830 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 struct rpc_xprt *xprt = req->rq_xprt;
832
Trond Myklebust5d008372008-02-22 16:34:17 -0500833 if (task->tk_status != -ETIMEDOUT)
834 return;
Chuck Lever46121cf2007-01-31 12:14:08 -0500835 dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
Chuck Lever46c0ee82005-08-25 16:25:52 -0700836
Trond Myklebust5d008372008-02-22 16:34:17 -0500837 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400838 if (!req->rq_reply_bytes_recvd) {
Chuck Lever46c0ee82005-08-25 16:25:52 -0700839 if (xprt->ops->timer)
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500840 xprt->ops->timer(xprt, task);
Trond Myklebust5d008372008-02-22 16:34:17 -0500841 } else
842 task->tk_status = 0;
843 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844}
845
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300846static inline int xprt_has_timer(struct rpc_xprt *xprt)
847{
848 return xprt->idle_timeout != 0;
849}
850
Chuck Lever9903cd12005-08-11 16:25:26 -0400851/**
852 * xprt_prepare_transmit - reserve the transport before sending a request
853 * @task: RPC task about to send a request
854 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 */
Trond Myklebust90051ea2013-09-25 12:17:18 -0400856bool xprt_prepare_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857{
858 struct rpc_rqst *req = task->tk_rqstp;
859 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebust90051ea2013-09-25 12:17:18 -0400860 bool ret = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
Chuck Lever46121cf2007-01-31 12:14:08 -0500862 dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400864 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust8a19a0b2013-09-24 12:00:27 -0400865 if (!req->rq_bytes_sent) {
866 if (req->rq_reply_bytes_recvd) {
867 task->tk_status = req->rq_reply_bytes_recvd;
868 goto out_unlock;
869 }
870 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
871 && xprt_connected(xprt)
872 && req->rq_connect_cookie == xprt->connect_cookie) {
873 xprt->ops->set_retrans_timeout(task);
874 rpc_sleep_on(&xprt->pending, task, xprt_timer);
875 goto out_unlock;
876 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 }
Trond Myklebust90051ea2013-09-25 12:17:18 -0400878 if (!xprt->ops->reserve_xprt(xprt, task)) {
879 task->tk_status = -EAGAIN;
880 goto out_unlock;
881 }
882 ret = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883out_unlock:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400884 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebust90051ea2013-09-25 12:17:18 -0400885 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886}
887
Trond Myklebuste0ab53d2006-07-27 17:22:50 -0400888void xprt_end_transmit(struct rpc_task *task)
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700889{
Rahul Iyer343952f2009-04-01 09:23:17 -0400890 xprt_release_write(task->tk_rqstp->rq_xprt, task);
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700891}
892
Chuck Lever9903cd12005-08-11 16:25:26 -0400893/**
894 * xprt_transmit - send an RPC request on a transport
895 * @task: controlling RPC task
896 *
897 * We have to copy the iovec because sendmsg fiddles with its contents.
898 */
899void xprt_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 struct rpc_rqst *req = task->tk_rqstp;
902 struct rpc_xprt *xprt = req->rq_xprt;
Andy Adamson15a45202012-02-14 16:19:18 -0500903 int status, numreqs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
Chuck Lever46121cf2007-01-31 12:14:08 -0500905 dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400907 if (!req->rq_reply_bytes_recvd) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400908 if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
909 /*
910 * Add to the list only if we're expecting a reply
911 */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400912 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 /* Update the softirq receive buffer */
914 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
915 sizeof(req->rq_private_buf));
916 /* Add request to the receive list */
917 list_add_tail(&req->rq_list, &xprt->recv);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400918 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 xprt_reset_majortimeo(req);
Trond Myklebust0f9dc2b2005-06-22 17:16:28 +0000920 /* Turn off autodisconnect */
921 del_singleshot_timer_sync(&xprt->timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 }
923 } else if (!req->rq_bytes_sent)
924 return;
925
Chuck Leverff839972010-05-07 13:34:47 -0400926 req->rq_xtime = ktime_get();
Chuck Levera246b012005-08-11 16:25:23 -0400927 status = xprt->ops->send_request(task);
Trond Myklebustc8485e42009-03-11 14:37:59 -0400928 if (status != 0) {
929 task->tk_status = status;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700930 return;
931 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932
Trond Myklebustc8485e42009-03-11 14:37:59 -0400933 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
Bryan Schumaker468f8612011-04-18 15:57:32 -0400934 task->tk_flags |= RPC_TASK_SENT;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400935 spin_lock_bh(&xprt->transport_lock);
936
937 xprt->ops->set_retrans_timeout(task);
938
Andy Adamson15a45202012-02-14 16:19:18 -0500939 numreqs = atomic_read(&xprt->num_reqs);
940 if (numreqs > xprt->stat.max_slots)
941 xprt->stat.max_slots = numreqs;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400942 xprt->stat.sends++;
943 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
944 xprt->stat.bklog_u += xprt->backlog.qlen;
Andy Adamson15a45202012-02-14 16:19:18 -0500945 xprt->stat.sending_u += xprt->sending.qlen;
946 xprt->stat.pending_u += xprt->pending.qlen;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400947
948 /* Don't race with disconnect */
949 if (!xprt_connected(xprt))
950 task->tk_status = -ENOTCONN;
Trond Myklebust0a660522013-09-25 11:31:54 -0400951 else {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400952 /*
953 * Sleep on the pending queue since
954 * we're expecting a reply.
955 */
Trond Myklebust0a660522013-09-25 11:31:54 -0400956 if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task))
957 rpc_sleep_on(&xprt->pending, task, xprt_timer);
958 req->rq_connect_cookie = xprt->connect_cookie;
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400959 }
Trond Myklebustc8485e42009-03-11 14:37:59 -0400960 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961}
962
Trond Myklebustba60eb22013-04-14 10:49:37 -0400963static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
964{
965 set_bit(XPRT_CONGESTED, &xprt->state);
966 rpc_sleep_on(&xprt->backlog, task, NULL);
967}
968
969static void xprt_wake_up_backlog(struct rpc_xprt *xprt)
970{
971 if (rpc_wake_up_next(&xprt->backlog) == NULL)
972 clear_bit(XPRT_CONGESTED, &xprt->state);
973}
974
975static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
976{
977 bool ret = false;
978
979 if (!test_bit(XPRT_CONGESTED, &xprt->state))
980 goto out;
981 spin_lock(&xprt->reserve_lock);
982 if (test_bit(XPRT_CONGESTED, &xprt->state)) {
983 rpc_sleep_on(&xprt->backlog, task, NULL);
984 ret = true;
985 }
986 spin_unlock(&xprt->reserve_lock);
987out:
988 return ret;
989}
990
Trond Myklebustd9ba1312011-07-17 18:11:30 -0400991static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
992{
993 struct rpc_rqst *req = ERR_PTR(-EAGAIN);
994
995 if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))
996 goto out;
997 req = kzalloc(sizeof(struct rpc_rqst), gfp_flags);
998 if (req != NULL)
999 goto out;
1000 atomic_dec(&xprt->num_reqs);
1001 req = ERR_PTR(-ENOMEM);
1002out:
1003 return req;
1004}
1005
1006static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1007{
1008 if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {
1009 kfree(req);
1010 return true;
1011 }
1012 return false;
1013}
1014
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001015void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016{
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001017 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001019 spin_lock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 if (!list_empty(&xprt->free)) {
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001021 req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1022 list_del(&req->rq_list);
1023 goto out_init_req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 }
Jeff Layton6b343092012-05-16 13:30:35 -04001025 req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001026 if (!IS_ERR(req))
1027 goto out_init_req;
1028 switch (PTR_ERR(req)) {
1029 case -ENOMEM:
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001030 dprintk("RPC: dynamic allocation of request slot "
1031 "failed! Retrying\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001032 task->tk_status = -ENOMEM;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001033 break;
1034 case -EAGAIN:
Trond Myklebustba60eb22013-04-14 10:49:37 -04001035 xprt_add_backlog(xprt, task);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001036 dprintk("RPC: waiting for request slot\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001037 default:
1038 task->tk_status = -EAGAIN;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001039 }
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001040 spin_unlock(&xprt->reserve_lock);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001041 return;
1042out_init_req:
1043 task->tk_status = 0;
1044 task->tk_rqstp = req;
1045 xprt_request_init(task, xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001046 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047}
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001048EXPORT_SYMBOL_GPL(xprt_alloc_slot);
1049
1050void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
1051{
1052 /* Note: grabbing the xprt_lock_write() ensures that we throttle
1053 * new slot allocation if the transport is congested (i.e. when
1054 * reconnecting a stream transport or when out of socket write
1055 * buffer space).
1056 */
1057 if (xprt_lock_write(xprt, task)) {
1058 xprt_alloc_slot(xprt, task);
1059 xprt_release_write(xprt, task);
1060 }
1061}
1062EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001064static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1065{
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001066 spin_lock(&xprt->reserve_lock);
Trond Myklebustc25573b2011-12-01 14:16:17 -05001067 if (!xprt_dynamic_free_slot(xprt, req)) {
1068 memset(req, 0, sizeof(*req)); /* mark unused */
1069 list_add(&req->rq_list, &xprt->free);
1070 }
Trond Myklebustba60eb22013-04-14 10:49:37 -04001071 xprt_wake_up_backlog(xprt);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001072 spin_unlock(&xprt->reserve_lock);
1073}
1074
Trond Myklebust21de0a92011-07-17 16:57:32 -04001075static void xprt_free_all_slots(struct rpc_xprt *xprt)
1076{
1077 struct rpc_rqst *req;
1078 while (!list_empty(&xprt->free)) {
1079 req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list);
1080 list_del(&req->rq_list);
1081 kfree(req);
1082 }
1083}
1084
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001085struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
1086 unsigned int num_prealloc,
1087 unsigned int max_alloc)
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001088{
1089 struct rpc_xprt *xprt;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001090 struct rpc_rqst *req;
1091 int i;
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001092
1093 xprt = kzalloc(size, GFP_KERNEL);
1094 if (xprt == NULL)
1095 goto out;
1096
Trond Myklebust21de0a92011-07-17 16:57:32 -04001097 xprt_init(xprt, net);
1098
1099 for (i = 0; i < num_prealloc; i++) {
1100 req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
1101 if (!req)
wangweidong83131642013-10-15 11:44:30 +08001102 goto out_free;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001103 list_add(&req->rq_list, &xprt->free);
1104 }
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001105 if (max_alloc > num_prealloc)
1106 xprt->max_reqs = max_alloc;
1107 else
1108 xprt->max_reqs = num_prealloc;
1109 xprt->min_reqs = num_prealloc;
1110 atomic_set(&xprt->num_reqs, num_prealloc);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001111
1112 return xprt;
1113
1114out_free:
Trond Myklebust21de0a92011-07-17 16:57:32 -04001115 xprt_free(xprt);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001116out:
1117 return NULL;
1118}
1119EXPORT_SYMBOL_GPL(xprt_alloc);
1120
Pavel Emelyanove204e622010-09-29 16:03:13 +04001121void xprt_free(struct rpc_xprt *xprt)
1122{
Pavel Emelyanov37aa2132010-09-29 16:05:43 +04001123 put_net(xprt->xprt_net);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001124 xprt_free_all_slots(xprt);
Pavel Emelyanove204e622010-09-29 16:03:13 +04001125 kfree(xprt);
1126}
1127EXPORT_SYMBOL_GPL(xprt_free);
1128
Chuck Lever9903cd12005-08-11 16:25:26 -04001129/**
1130 * xprt_reserve - allocate an RPC request slot
1131 * @task: RPC task requesting a slot allocation
1132 *
Trond Myklebustba60eb22013-04-14 10:49:37 -04001133 * If the transport is marked as being congested, or if no more
1134 * slots are available, place the task on the transport's
Chuck Lever9903cd12005-08-11 16:25:26 -04001135 * backlog queue.
1136 */
1137void xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138{
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001139 struct rpc_xprt *xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001141 task->tk_status = 0;
1142 if (task->tk_rqstp != NULL)
1143 return;
1144
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001145 task->tk_timeout = 0;
1146 task->tk_status = -EAGAIN;
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001147 rcu_read_lock();
1148 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustba60eb22013-04-14 10:49:37 -04001149 if (!xprt_throttle_congested(xprt, task))
1150 xprt->ops->alloc_slot(xprt, task);
1151 rcu_read_unlock();
1152}
1153
1154/**
1155 * xprt_retry_reserve - allocate an RPC request slot
1156 * @task: RPC task requesting a slot allocation
1157 *
1158 * If no more slots are available, place the task on the transport's
1159 * backlog queue.
1160 * Note that the only difference with xprt_reserve is that we now
1161 * ignore the value of the XPRT_CONGESTED flag.
1162 */
1163void xprt_retry_reserve(struct rpc_task *task)
1164{
1165 struct rpc_xprt *xprt;
1166
1167 task->tk_status = 0;
1168 if (task->tk_rqstp != NULL)
1169 return;
1170
1171 task->tk_timeout = 0;
1172 task->tk_status = -EAGAIN;
1173 rcu_read_lock();
1174 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001175 xprt->ops->alloc_slot(xprt, task);
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001176 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177}
1178
Alexey Dobriyand8ed0292006-09-26 22:29:38 -07001179static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180{
Eric Dumazet0eae88f2010-04-20 19:06:52 -07001181 return (__force __be32)xprt->xid++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182}
1183
1184static inline void xprt_init_xid(struct rpc_xprt *xprt)
1185{
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -05001186 xprt->xid = prandom_u32();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187}
1188
Chuck Lever9903cd12005-08-11 16:25:26 -04001189static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190{
1191 struct rpc_rqst *req = task->tk_rqstp;
1192
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001193 INIT_LIST_HEAD(&req->rq_list);
Trond Myklebustba7392b2007-12-20 16:03:55 -05001194 req->rq_timeout = task->tk_client->cl_timeout->to_initval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 req->rq_task = task;
1196 req->rq_xprt = xprt;
Chuck Lever02107142006-01-03 09:55:49 +01001197 req->rq_buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 req->rq_xid = xprt_alloc_xid(xprt);
Trond Myklebust0a660522013-09-25 11:31:54 -04001199 req->rq_connect_cookie = xprt->connect_cookie - 1;
Trond Myklebust92551942013-09-27 11:28:40 -04001200 req->rq_bytes_sent = 0;
1201 req->rq_snd_buf.len = 0;
1202 req->rq_snd_buf.buflen = 0;
1203 req->rq_rcv_buf.len = 0;
1204 req->rq_rcv_buf.buflen = 0;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001205 req->rq_release_snd_buf = NULL;
Trond Myklebustda458282006-08-31 15:44:52 -04001206 xprt_reset_majortimeo(req);
Chuck Lever46121cf2007-01-31 12:14:08 -05001207 dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 req, ntohl(req->rq_xid));
1209}
1210
Chuck Lever9903cd12005-08-11 16:25:26 -04001211/**
1212 * xprt_release - release an RPC request slot
1213 * @task: task which is finished with the slot
1214 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 */
Chuck Lever9903cd12005-08-11 16:25:26 -04001216void xprt_release(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217{
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001218 struct rpc_xprt *xprt;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001219 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220
Trond Myklebust87ed5002013-01-07 14:30:46 -05001221 if (req == NULL) {
1222 if (task->tk_client) {
1223 rcu_read_lock();
1224 xprt = rcu_dereference(task->tk_client->cl_xprt);
1225 if (xprt->snd_task == task)
1226 xprt_release_write(xprt, task);
1227 rcu_read_unlock();
1228 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 return;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001230 }
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001231
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001232 xprt = req->rq_xprt;
Weston Andros Adamson0a702192012-02-17 13:15:24 -05001233 if (task->tk_ops->rpc_count_stats != NULL)
1234 task->tk_ops->rpc_count_stats(task, task->tk_calldata);
1235 else if (task->tk_client)
1236 rpc_count_iostats(task, task->tk_client->cl_metrics);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001237 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -07001238 xprt->ops->release_xprt(xprt, task);
Chuck Levera58dd392005-08-25 16:25:53 -07001239 if (xprt->ops->release_request)
1240 xprt->ops->release_request(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 if (!list_empty(&req->rq_list))
1242 list_del(&req->rq_list);
1243 xprt->last_used = jiffies;
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001244 if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
Chuck Levera246b012005-08-11 16:25:23 -04001245 mod_timer(&xprt->timer,
Chuck Lever03bf4b72005-08-25 16:25:55 -07001246 xprt->last_used + xprt->idle_timeout);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001247 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001248 if (req->rq_buffer)
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001249 xprt->ops->buf_free(req->rq_buffer);
Trond Myklebusta17c2152010-07-31 14:29:08 -04001250 if (req->rq_cred != NULL)
1251 put_rpccred(req->rq_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 task->tk_rqstp = NULL;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001253 if (req->rq_release_snd_buf)
1254 req->rq_release_snd_buf(req);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001255
Chuck Lever46121cf2007-01-31 12:14:08 -05001256 dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001257 if (likely(!bc_prealloc(req)))
1258 xprt_free_slot(xprt, req);
1259 else
Trond Myklebustc9acb422010-03-19 15:36:22 -04001260 xprt_free_bc_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261}
1262
Trond Myklebust21de0a92011-07-17 16:57:32 -04001263static void xprt_init(struct rpc_xprt *xprt, struct net *net)
Chuck Leverc2866762006-08-22 20:06:20 -04001264{
Trond Myklebust21de0a92011-07-17 16:57:32 -04001265 atomic_set(&xprt->count, 1);
Chuck Leverc2866762006-08-22 20:06:20 -04001266
1267 spin_lock_init(&xprt->transport_lock);
1268 spin_lock_init(&xprt->reserve_lock);
1269
1270 INIT_LIST_HEAD(&xprt->free);
1271 INIT_LIST_HEAD(&xprt->recv);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001272#if defined(CONFIG_SUNRPC_BACKCHANNEL)
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001273 spin_lock_init(&xprt->bc_pa_lock);
1274 INIT_LIST_HEAD(&xprt->bc_pa_list);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001275#endif /* CONFIG_SUNRPC_BACKCHANNEL */
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001276
Chuck Leverc2866762006-08-22 20:06:20 -04001277 xprt->last_used = jiffies;
1278 xprt->cwnd = RPC_INITCWND;
Chuck Levera5090502007-03-29 16:48:04 -04001279 xprt->bind_index = 0;
Chuck Leverc2866762006-08-22 20:06:20 -04001280
1281 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
1282 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
Trond Myklebust34006ce2011-07-17 18:11:34 -04001283 rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending");
Chuck Leverc2866762006-08-22 20:06:20 -04001284 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1285
Chuck Leverc2866762006-08-22 20:06:20 -04001286 xprt_init_xid(xprt);
1287
Trond Myklebust21de0a92011-07-17 16:57:32 -04001288 xprt->xprt_net = get_net(net);
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001289}
1290
1291/**
1292 * xprt_create_transport - create an RPC transport
1293 * @args: rpc transport creation arguments
1294 *
1295 */
1296struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
1297{
1298 struct rpc_xprt *xprt;
1299 struct xprt_class *t;
1300
1301 spin_lock(&xprt_list_lock);
1302 list_for_each_entry(t, &xprt_list, list) {
1303 if (t->ident == args->ident) {
1304 spin_unlock(&xprt_list_lock);
1305 goto found;
1306 }
1307 }
1308 spin_unlock(&xprt_list_lock);
1309 printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
1310 return ERR_PTR(-EIO);
1311
1312found:
1313 xprt = t->setup(args);
1314 if (IS_ERR(xprt)) {
1315 dprintk("RPC: xprt_create_transport: failed, %ld\n",
1316 -PTR_ERR(xprt));
Trond Myklebust21de0a92011-07-17 16:57:32 -04001317 goto out;
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001318 }
J. Bruce Fields33d90ac2013-04-11 15:06:36 -04001319 if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
1320 xprt->idle_timeout = 0;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001321 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
1322 if (xprt_has_timer(xprt))
1323 setup_timer(&xprt->timer, xprt_init_autodisconnect,
1324 (unsigned long)xprt);
1325 else
1326 init_timer(&xprt->timer);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001327
1328 if (strlen(args->servername) > RPC_MAXNETNAMELEN) {
1329 xprt_destroy(xprt);
1330 return ERR_PTR(-EINVAL);
1331 }
1332 xprt->servername = kstrdup(args->servername, GFP_KERNEL);
1333 if (xprt->servername == NULL) {
1334 xprt_destroy(xprt);
1335 return ERR_PTR(-ENOMEM);
1336 }
1337
Chuck Lever46121cf2007-01-31 12:14:08 -05001338 dprintk("RPC: created transport %p with %u slots\n", xprt,
Chuck Leverc2866762006-08-22 20:06:20 -04001339 xprt->max_reqs);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001340out:
Chuck Leverc2866762006-08-22 20:06:20 -04001341 return xprt;
1342}
1343
Chuck Lever9903cd12005-08-11 16:25:26 -04001344/**
1345 * xprt_destroy - destroy an RPC transport, killing off all requests.
Trond Myklebusta8de2402011-03-15 19:56:30 -04001346 * @xprt: transport to destroy
Chuck Lever9903cd12005-08-11 16:25:26 -04001347 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 */
Trond Myklebusta8de2402011-03-15 19:56:30 -04001349static void xprt_destroy(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350{
Chuck Lever46121cf2007-01-31 12:14:08 -05001351 dprintk("RPC: destroying transport %p\n", xprt);
Trond Myklebust0065db32006-01-03 09:55:56 +01001352 del_timer_sync(&xprt->timer);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001353
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001354 rpc_destroy_wait_queue(&xprt->binding);
1355 rpc_destroy_wait_queue(&xprt->pending);
1356 rpc_destroy_wait_queue(&xprt->sending);
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001357 rpc_destroy_wait_queue(&xprt->backlog);
J. Bruce Fieldsc3ae62ae2010-08-03 17:22:20 -04001358 cancel_work_sync(&xprt->task_cleanup);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001359 kfree(xprt->servername);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001360 /*
1361 * Tear down transport state and free the rpc_xprt
1362 */
Chuck Levera246b012005-08-11 16:25:23 -04001363 xprt->ops->destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001364}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001366/**
1367 * xprt_put - release a reference to an RPC transport.
1368 * @xprt: pointer to the transport
1369 *
1370 */
1371void xprt_put(struct rpc_xprt *xprt)
1372{
Trond Myklebusta8de2402011-03-15 19:56:30 -04001373 if (atomic_dec_and_test(&xprt->count))
1374 xprt_destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001375}