blob: fd46d42afa89ed89e6fe2813822f7570e6683160 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Chuck Levera246b012005-08-11 16:25:23 -040047#include <linux/sunrpc/clnt.h>
Chuck Lever11c556b2006-03-20 13:44:22 -050048#include <linux/sunrpc/metrics.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -040050#include "sunrpc.h"
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052/*
53 * Local variables
54 */
55
56#ifdef RPC_DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070057# define RPCDBG_FACILITY RPCDBG_XPRT
58#endif
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060/*
61 * Local functions
62 */
63static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
64static inline void do_xprt_reserve(struct rpc_task *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065static void xprt_connect_status(struct rpc_task *task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
67
Jiri Slaby5ba03e82007-11-22 19:40:22 +080068static DEFINE_SPINLOCK(xprt_list_lock);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040069static LIST_HEAD(xprt_list);
70
Chuck Lever555ee3a2005-08-25 16:25:54 -070071/*
72 * The transport code maintains an estimate on the maximum number of out-
73 * standing RPC requests, using a smoothed version of the congestion
74 * avoidance implemented in 44BSD. This is basically the Van Jacobson
75 * congestion algorithm: If a retransmit occurs, the congestion window is
76 * halved; otherwise, it is incremented by 1/cwnd when
77 *
78 * - a reply is received and
79 * - a full number of requests are outstanding and
80 * - the congestion window hasn't been updated recently.
81 */
82#define RPC_CWNDSHIFT (8U)
83#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
84#define RPC_INITCWND RPC_CWNDSCALE
85#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
86
87#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Chuck Lever12a80462005-08-25 16:25:51 -070089/**
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040090 * xprt_register_transport - register a transport implementation
91 * @transport: transport to register
92 *
93 * If a transport implementation is loaded as a kernel module, it can
94 * call this interface to make itself known to the RPC client.
95 *
96 * Returns:
97 * 0: transport successfully registered
98 * -EEXIST: transport already registered
99 * -EINVAL: transport module being unloaded
100 */
101int xprt_register_transport(struct xprt_class *transport)
102{
103 struct xprt_class *t;
104 int result;
105
106 result = -EEXIST;
107 spin_lock(&xprt_list_lock);
108 list_for_each_entry(t, &xprt_list, list) {
109 /* don't register the same transport class twice */
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -0400110 if (t->ident == transport->ident)
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400111 goto out;
112 }
113
Denis V. Lunevc9f6cde2008-07-31 09:53:56 +0400114 list_add_tail(&transport->list, &xprt_list);
115 printk(KERN_INFO "RPC: Registered %s transport module.\n",
116 transport->name);
117 result = 0;
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400118
119out:
120 spin_unlock(&xprt_list_lock);
121 return result;
122}
123EXPORT_SYMBOL_GPL(xprt_register_transport);
124
125/**
126 * xprt_unregister_transport - unregister a transport implementation
Randy Dunlap65b6e422008-02-13 15:03:23 -0800127 * @transport: transport to unregister
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400128 *
129 * Returns:
130 * 0: transport successfully unregistered
131 * -ENOENT: transport never registered
132 */
133int xprt_unregister_transport(struct xprt_class *transport)
134{
135 struct xprt_class *t;
136 int result;
137
138 result = 0;
139 spin_lock(&xprt_list_lock);
140 list_for_each_entry(t, &xprt_list, list) {
141 if (t == transport) {
142 printk(KERN_INFO
143 "RPC: Unregistered %s transport module.\n",
144 transport->name);
145 list_del_init(&transport->list);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400146 goto out;
147 }
148 }
149 result = -ENOENT;
150
151out:
152 spin_unlock(&xprt_list_lock);
153 return result;
154}
155EXPORT_SYMBOL_GPL(xprt_unregister_transport);
156
157/**
Tom Talpey441e3e22009-03-11 14:37:56 -0400158 * xprt_load_transport - load a transport implementation
159 * @transport_name: transport to load
160 *
161 * Returns:
162 * 0: transport successfully loaded
163 * -ENOENT: transport module not available
164 */
165int xprt_load_transport(const char *transport_name)
166{
167 struct xprt_class *t;
168 char module_name[sizeof t->name + 5];
169 int result;
170
171 result = 0;
172 spin_lock(&xprt_list_lock);
173 list_for_each_entry(t, &xprt_list, list) {
174 if (strcmp(t->name, transport_name) == 0) {
175 spin_unlock(&xprt_list_lock);
176 goto out;
177 }
178 }
179 spin_unlock(&xprt_list_lock);
180 strcpy(module_name, "xprt");
181 strncat(module_name, transport_name, sizeof t->name);
182 result = request_module(module_name);
183out:
184 return result;
185}
186EXPORT_SYMBOL_GPL(xprt_load_transport);
187
188/**
Chuck Lever12a80462005-08-25 16:25:51 -0700189 * xprt_reserve_xprt - serialize write access to transports
190 * @task: task that is requesting access to the transport
191 *
192 * This prevents mixing the payload of separate requests, and prevents
193 * transport connects from colliding with writes. No congestion control
194 * is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 */
Chuck Lever12a80462005-08-25 16:25:51 -0700196int xprt_reserve_xprt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197{
Chuck Lever12a80462005-08-25 16:25:51 -0700198 struct rpc_rqst *req = task->tk_rqstp;
Rahul Iyer343952f2009-04-01 09:23:17 -0400199 struct rpc_xprt *xprt = req->rq_xprt;
Chuck Lever12a80462005-08-25 16:25:51 -0700200
201 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
202 if (task == xprt->snd_task)
203 return 1;
204 if (task == NULL)
205 return 0;
206 goto out_sleep;
207 }
208 xprt->snd_task = task;
209 if (req) {
210 req->rq_bytes_sent = 0;
211 req->rq_ntrans++;
212 }
213 return 1;
214
215out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500216 dprintk("RPC: %5u failed to lock transport %p\n",
Chuck Lever12a80462005-08-25 16:25:51 -0700217 task->tk_pid, xprt);
218 task->tk_timeout = 0;
219 task->tk_status = -EAGAIN;
220 if (req && req->rq_ntrans)
Trond Myklebust5d008372008-02-22 16:34:17 -0500221 rpc_sleep_on(&xprt->resend, task, NULL);
Chuck Lever12a80462005-08-25 16:25:51 -0700222 else
Trond Myklebust5d008372008-02-22 16:34:17 -0500223 rpc_sleep_on(&xprt->sending, task, NULL);
Chuck Lever12a80462005-08-25 16:25:51 -0700224 return 0;
225}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400226EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
Chuck Lever12a80462005-08-25 16:25:51 -0700227
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100228static void xprt_clear_locked(struct rpc_xprt *xprt)
229{
230 xprt->snd_task = NULL;
231 if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) {
232 smp_mb__before_clear_bit();
233 clear_bit(XPRT_LOCKED, &xprt->state);
234 smp_mb__after_clear_bit();
235 } else
Trond Myklebustc1384c92007-06-14 18:00:42 -0400236 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100237}
238
Chuck Lever12a80462005-08-25 16:25:51 -0700239/*
240 * xprt_reserve_xprt_cong - serialize write access to transports
241 * @task: task that is requesting access to the transport
242 *
243 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
244 * integrated into the decision of whether a request is allowed to be
245 * woken up and given access to the transport.
246 */
247int xprt_reserve_xprt_cong(struct rpc_task *task)
248{
249 struct rpc_xprt *xprt = task->tk_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 struct rpc_rqst *req = task->tk_rqstp;
251
Chuck Lever2226feb2005-08-11 16:25:38 -0400252 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 if (task == xprt->snd_task)
254 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 goto out_sleep;
256 }
Chuck Lever12a80462005-08-25 16:25:51 -0700257 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 xprt->snd_task = task;
259 if (req) {
260 req->rq_bytes_sent = 0;
261 req->rq_ntrans++;
262 }
263 return 1;
264 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100265 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500267 dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 task->tk_timeout = 0;
269 task->tk_status = -EAGAIN;
270 if (req && req->rq_ntrans)
Trond Myklebust5d008372008-02-22 16:34:17 -0500271 rpc_sleep_on(&xprt->resend, task, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 else
Trond Myklebust5d008372008-02-22 16:34:17 -0500273 rpc_sleep_on(&xprt->sending, task, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return 0;
275}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400276EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
Chuck Lever12a80462005-08-25 16:25:51 -0700278static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279{
280 int retval;
281
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400282 spin_lock_bh(&xprt->transport_lock);
Chuck Lever12a80462005-08-25 16:25:51 -0700283 retval = xprt->ops->reserve_xprt(task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400284 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return retval;
286}
287
Chuck Lever12a80462005-08-25 16:25:51 -0700288static void __xprt_lock_write_next(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
290 struct rpc_task *task;
Chuck Lever49e9a892005-08-25 16:25:51 -0700291 struct rpc_rqst *req;
292
293 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
294 return;
295
296 task = rpc_wake_up_next(&xprt->resend);
297 if (!task) {
298 task = rpc_wake_up_next(&xprt->sending);
299 if (!task)
300 goto out_unlock;
301 }
302
303 req = task->tk_rqstp;
304 xprt->snd_task = task;
305 if (req) {
306 req->rq_bytes_sent = 0;
307 req->rq_ntrans++;
308 }
309 return;
310
311out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100312 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700313}
314
315static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
316{
317 struct rpc_task *task;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Chuck Lever2226feb2005-08-11 16:25:38 -0400319 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 return;
Chuck Lever49e9a892005-08-25 16:25:51 -0700321 if (RPCXPRT_CONGESTED(xprt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 goto out_unlock;
323 task = rpc_wake_up_next(&xprt->resend);
324 if (!task) {
325 task = rpc_wake_up_next(&xprt->sending);
326 if (!task)
327 goto out_unlock;
328 }
Chuck Lever49e9a892005-08-25 16:25:51 -0700329 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 struct rpc_rqst *req = task->tk_rqstp;
331 xprt->snd_task = task;
332 if (req) {
333 req->rq_bytes_sent = 0;
334 req->rq_ntrans++;
335 }
336 return;
337 }
338out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100339 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340}
341
Chuck Lever49e9a892005-08-25 16:25:51 -0700342/**
343 * xprt_release_xprt - allow other requests to use a transport
344 * @xprt: transport with other tasks potentially waiting
345 * @task: task that is releasing access to the transport
346 *
347 * Note that "task" can be NULL. No congestion control is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 */
Chuck Lever49e9a892005-08-25 16:25:51 -0700349void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350{
351 if (xprt->snd_task == task) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100352 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 __xprt_lock_write_next(xprt);
354 }
355}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400356EXPORT_SYMBOL_GPL(xprt_release_xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
Chuck Lever49e9a892005-08-25 16:25:51 -0700358/**
359 * xprt_release_xprt_cong - allow other requests to use a transport
360 * @xprt: transport with other tasks potentially waiting
361 * @task: task that is releasing access to the transport
362 *
363 * Note that "task" can be NULL. Another task is awoken to use the
364 * transport if the transport's congestion window allows it.
365 */
366void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
367{
368 if (xprt->snd_task == task) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100369 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700370 __xprt_lock_write_next_cong(xprt);
371 }
372}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400373EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
Chuck Lever49e9a892005-08-25 16:25:51 -0700374
375static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376{
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400377 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -0700378 xprt->ops->release_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400379 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380}
381
382/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 * Van Jacobson congestion avoidance. Check if the congestion window
384 * overflowed. Put the task to sleep if this is the case.
385 */
386static int
387__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
388{
389 struct rpc_rqst *req = task->tk_rqstp;
390
391 if (req->rq_cong)
392 return 1;
Chuck Lever46121cf2007-01-31 12:14:08 -0500393 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 task->tk_pid, xprt->cong, xprt->cwnd);
395 if (RPCXPRT_CONGESTED(xprt))
396 return 0;
397 req->rq_cong = 1;
398 xprt->cong += RPC_CWNDSCALE;
399 return 1;
400}
401
402/*
403 * Adjust the congestion window, and wake up the next task
404 * that has been sleeping due to congestion
405 */
406static void
407__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
408{
409 if (!req->rq_cong)
410 return;
411 req->rq_cong = 0;
412 xprt->cong -= RPC_CWNDSCALE;
Chuck Lever49e9a892005-08-25 16:25:51 -0700413 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414}
415
Chuck Lever46c0ee82005-08-25 16:25:52 -0700416/**
Chuck Levera58dd392005-08-25 16:25:53 -0700417 * xprt_release_rqst_cong - housekeeping when request is complete
418 * @task: RPC request that recently completed
419 *
420 * Useful for transports that require congestion control.
421 */
422void xprt_release_rqst_cong(struct rpc_task *task)
423{
424 __xprt_put_cong(task->tk_xprt, task->tk_rqstp);
425}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400426EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
Chuck Levera58dd392005-08-25 16:25:53 -0700427
428/**
Chuck Lever46c0ee82005-08-25 16:25:52 -0700429 * xprt_adjust_cwnd - adjust transport congestion window
430 * @task: recently completed RPC request used to adjust window
431 * @result: result code of completed RPC request
432 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
434 */
Chuck Lever46c0ee82005-08-25 16:25:52 -0700435void xprt_adjust_cwnd(struct rpc_task *task, int result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700437 struct rpc_rqst *req = task->tk_rqstp;
438 struct rpc_xprt *xprt = task->tk_xprt;
439 unsigned long cwnd = xprt->cwnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 if (result >= 0 && cwnd <= xprt->cong) {
442 /* The (cwnd >> 1) term makes sure
443 * the result gets rounded properly. */
444 cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
445 if (cwnd > RPC_MAXCWND(xprt))
446 cwnd = RPC_MAXCWND(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700447 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 } else if (result == -ETIMEDOUT) {
449 cwnd >>= 1;
450 if (cwnd < RPC_CWNDSCALE)
451 cwnd = RPC_CWNDSCALE;
452 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500453 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 xprt->cong, xprt->cwnd, cwnd);
455 xprt->cwnd = cwnd;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700456 __xprt_put_cong(xprt, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400458EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
Chuck Lever44fbac22005-08-11 16:25:44 -0400460/**
461 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
462 * @xprt: transport with waiting tasks
463 * @status: result code to plant in each task before waking it
464 *
465 */
466void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
467{
468 if (status < 0)
469 rpc_wake_up_status(&xprt->pending, status);
470 else
471 rpc_wake_up(&xprt->pending);
472}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400473EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
Chuck Lever44fbac22005-08-11 16:25:44 -0400474
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400475/**
476 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
477 * @task: task to be put to sleep
Randy Dunlap0b80ae42008-04-26 22:59:02 -0700478 * @action: function pointer to be executed after wait
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400479 */
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400480void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400481{
482 struct rpc_rqst *req = task->tk_rqstp;
483 struct rpc_xprt *xprt = req->rq_xprt;
484
485 task->tk_timeout = req->rq_timeout;
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400486 rpc_sleep_on(&xprt->pending, task, action);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400487}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400488EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400489
490/**
491 * xprt_write_space - wake the task waiting for transport output buffer space
492 * @xprt: transport with waiting tasks
493 *
494 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
495 */
496void xprt_write_space(struct rpc_xprt *xprt)
497{
498 if (unlikely(xprt->shutdown))
499 return;
500
501 spin_lock_bh(&xprt->transport_lock);
502 if (xprt->snd_task) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500503 dprintk("RPC: write space: waking waiting task on "
504 "xprt %p\n", xprt);
Trond Myklebustfda13932008-02-22 16:34:12 -0500505 rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400506 }
507 spin_unlock_bh(&xprt->transport_lock);
508}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400509EXPORT_SYMBOL_GPL(xprt_write_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400510
Chuck Leverfe3aca22005-08-25 16:25:50 -0700511/**
512 * xprt_set_retrans_timeout_def - set a request's retransmit timeout
513 * @task: task whose timeout is to be set
514 *
515 * Set a request's retransmit timeout based on the transport's
516 * default timeout parameters. Used by transports that don't adjust
517 * the retransmit timeout based on round-trip time estimation.
518 */
519void xprt_set_retrans_timeout_def(struct rpc_task *task)
520{
521 task->tk_timeout = task->tk_rqstp->rq_timeout;
522}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400523EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700524
525/*
526 * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
527 * @task: task whose timeout is to be set
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800528 *
Chuck Leverfe3aca22005-08-25 16:25:50 -0700529 * Set a request's retransmit timeout using the RTT estimator.
530 */
531void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
532{
533 int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500534 struct rpc_clnt *clnt = task->tk_client;
535 struct rpc_rtt *rtt = clnt->cl_rtt;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700536 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500537 unsigned long max_timeout = clnt->cl_timeout->to_maxval;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700538
539 task->tk_timeout = rpc_calc_rto(rtt, timer);
540 task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
541 if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
542 task->tk_timeout = max_timeout;
543}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400544EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546static void xprt_reset_majortimeo(struct rpc_rqst *req)
547{
Trond Myklebustba7392b2007-12-20 16:03:55 -0500548 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 req->rq_majortimeo = req->rq_timeout;
551 if (to->to_exponential)
552 req->rq_majortimeo <<= to->to_retries;
553 else
554 req->rq_majortimeo += to->to_increment * to->to_retries;
555 if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
556 req->rq_majortimeo = to->to_maxval;
557 req->rq_majortimeo += jiffies;
558}
559
Chuck Lever9903cd12005-08-11 16:25:26 -0400560/**
561 * xprt_adjust_timeout - adjust timeout values for next retransmit
562 * @req: RPC request containing parameters to use for the adjustment
563 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 */
565int xprt_adjust_timeout(struct rpc_rqst *req)
566{
567 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500568 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 int status = 0;
570
571 if (time_before(jiffies, req->rq_majortimeo)) {
572 if (to->to_exponential)
573 req->rq_timeout <<= 1;
574 else
575 req->rq_timeout += to->to_increment;
576 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
577 req->rq_timeout = to->to_maxval;
578 req->rq_retries++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 } else {
580 req->rq_timeout = to->to_initval;
581 req->rq_retries = 0;
582 xprt_reset_majortimeo(req);
583 /* Reset the RTT counters == "slow start" */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400584 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400586 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 status = -ETIMEDOUT;
588 }
589
590 if (req->rq_timeout == 0) {
591 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
592 req->rq_timeout = 5 * HZ;
593 }
594 return status;
595}
596
David Howells65f27f32006-11-22 14:55:48 +0000597static void xprt_autoclose(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598{
David Howells65f27f32006-11-22 14:55:48 +0000599 struct rpc_xprt *xprt =
600 container_of(work, struct rpc_xprt, task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
Chuck Levera246b012005-08-11 16:25:23 -0400602 xprt->ops->close(xprt);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500603 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 xprt_release_write(xprt, NULL);
605}
606
Chuck Lever9903cd12005-08-11 16:25:26 -0400607/**
Trond Myklebust62da3b22007-11-06 18:44:20 -0500608 * xprt_disconnect_done - mark a transport as disconnected
Chuck Lever9903cd12005-08-11 16:25:26 -0400609 * @xprt: transport to flag for disconnect
610 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 */
Trond Myklebust62da3b22007-11-06 18:44:20 -0500612void xprt_disconnect_done(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
Chuck Lever46121cf2007-01-31 12:14:08 -0500614 dprintk("RPC: disconnected transport %p\n", xprt);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400615 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 xprt_clear_connected(xprt);
Trond Myklebust2a491992009-03-11 14:38:00 -0400617 xprt_wake_pending_tasks(xprt, -EAGAIN);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400618 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619}
Trond Myklebust62da3b22007-11-06 18:44:20 -0500620EXPORT_SYMBOL_GPL(xprt_disconnect_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
Trond Myklebust66af1e52007-11-06 10:18:36 -0500622/**
623 * xprt_force_disconnect - force a transport to disconnect
624 * @xprt: transport to disconnect
625 *
626 */
627void xprt_force_disconnect(struct rpc_xprt *xprt)
628{
629 /* Don't race with the test_bit() in xprt_clear_locked() */
630 spin_lock_bh(&xprt->transport_lock);
631 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
632 /* Try to schedule an autoclose RPC call */
633 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
634 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400635 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500636 spin_unlock_bh(&xprt->transport_lock);
637}
Trond Myklebust66af1e52007-11-06 10:18:36 -0500638
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400639/**
640 * xprt_conditional_disconnect - force a transport to disconnect
641 * @xprt: transport to disconnect
642 * @cookie: 'connection cookie'
643 *
644 * This attempts to break the connection if and only if 'cookie' matches
645 * the current transport 'connection cookie'. It ensures that we don't
646 * try to break the connection more than once when we need to retransmit
647 * a batch of RPC requests.
648 *
649 */
650void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
651{
652 /* Don't race with the test_bit() in xprt_clear_locked() */
653 spin_lock_bh(&xprt->transport_lock);
654 if (cookie != xprt->connect_cookie)
655 goto out;
656 if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
657 goto out;
658 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
659 /* Try to schedule an autoclose RPC call */
660 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
661 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400662 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400663out:
664 spin_unlock_bh(&xprt->transport_lock);
665}
666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667static void
668xprt_init_autodisconnect(unsigned long data)
669{
670 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
671
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400672 spin_lock(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 if (!list_empty(&xprt->recv) || xprt->shutdown)
674 goto out_abort;
Chuck Lever2226feb2005-08-11 16:25:38 -0400675 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 goto out_abort;
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400677 spin_unlock(&xprt->transport_lock);
Trond Myklebustf75e6742009-04-21 17:18:20 -0400678 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
679 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 return;
681out_abort:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400682 spin_unlock(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683}
684
Chuck Lever9903cd12005-08-11 16:25:26 -0400685/**
686 * xprt_connect - schedule a transport connect operation
687 * @task: RPC task that is requesting the connect
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 *
689 */
690void xprt_connect(struct rpc_task *task)
691{
692 struct rpc_xprt *xprt = task->tk_xprt;
693
Chuck Lever46121cf2007-01-31 12:14:08 -0500694 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 xprt, (xprt_connected(xprt) ? "is" : "is not"));
696
Chuck Leverec739ef2006-08-22 20:06:15 -0400697 if (!xprt_bound(xprt)) {
Trond Myklebust01d37c42009-03-11 14:09:39 -0400698 task->tk_status = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 return;
700 }
701 if (!xprt_lock_write(xprt, task))
702 return;
703 if (xprt_connected(xprt))
Chuck Levera246b012005-08-11 16:25:23 -0400704 xprt_release_write(xprt, task);
705 else {
706 if (task->tk_rqstp)
707 task->tk_rqstp->rq_bytes_sent = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Chuck Lever03bf4b72005-08-25 16:25:55 -0700709 task->tk_timeout = xprt->connect_timeout;
Trond Myklebust5d008372008-02-22 16:34:17 -0500710 rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
Chuck Lever262ca072006-03-20 13:44:16 -0500711 xprt->stat.connect_start = jiffies;
Chuck Levera246b012005-08-11 16:25:23 -0400712 xprt->ops->connect(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715}
716
Chuck Lever9903cd12005-08-11 16:25:26 -0400717static void xprt_connect_status(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718{
719 struct rpc_xprt *xprt = task->tk_xprt;
720
Chuck Levercd983ef2008-06-11 17:56:13 -0400721 if (task->tk_status == 0) {
Chuck Lever262ca072006-03-20 13:44:16 -0500722 xprt->stat.connect_count++;
723 xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
Chuck Lever46121cf2007-01-31 12:14:08 -0500724 dprintk("RPC: %5u xprt_connect_status: connection established\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 task->tk_pid);
726 return;
727 }
728
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 switch (task->tk_status) {
Trond Myklebust2a491992009-03-11 14:38:00 -0400730 case -EAGAIN:
731 dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
Chuck Lever23475d62005-08-11 16:25:08 -0400732 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 case -ETIMEDOUT:
Chuck Lever46121cf2007-01-31 12:14:08 -0500734 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
735 "out\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 break;
737 default:
Chuck Lever46121cf2007-01-31 12:14:08 -0500738 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
739 "server %s\n", task->tk_pid, -task->tk_status,
740 task->tk_client->cl_server);
Chuck Lever23475d62005-08-11 16:25:08 -0400741 xprt_release_write(xprt, task);
742 task->tk_status = -EIO;
Chuck Lever23475d62005-08-11 16:25:08 -0400743 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744}
745
Chuck Lever9903cd12005-08-11 16:25:26 -0400746/**
747 * xprt_lookup_rqst - find an RPC request corresponding to an XID
748 * @xprt: transport on which the original request was transmitted
749 * @xid: RPC XID of incoming reply
750 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700752struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
754 struct list_head *pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756 list_for_each(pos, &xprt->recv) {
757 struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list);
Chuck Lever262ca072006-03-20 13:44:16 -0500758 if (entry->rq_xid == xid)
759 return entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500761
762 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
763 ntohl(xid));
Chuck Lever262ca072006-03-20 13:44:16 -0500764 xprt->stat.bad_xids++;
765 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400767EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
Chuck Lever9903cd12005-08-11 16:25:26 -0400769/**
Chuck Lever1570c1e2005-08-25 16:25:52 -0700770 * xprt_update_rtt - update an RPC client's RTT state after receiving a reply
771 * @task: RPC request that recently completed
Chuck Lever9903cd12005-08-11 16:25:26 -0400772 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 */
Chuck Lever1570c1e2005-08-25 16:25:52 -0700774void xprt_update_rtt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775{
Chuck Lever1570c1e2005-08-25 16:25:52 -0700776 struct rpc_rqst *req = task->tk_rqstp;
777 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
778 unsigned timer = task->tk_msg.rpc_proc->p_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
Chuck Lever1570c1e2005-08-25 16:25:52 -0700780 if (timer) {
781 if (req->rq_ntrans == 1)
782 rpc_update_rtt(rtt, timer,
783 (long)jiffies - req->rq_xtime);
784 rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 }
Chuck Lever1570c1e2005-08-25 16:25:52 -0700786}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400787EXPORT_SYMBOL_GPL(xprt_update_rtt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788
Chuck Lever1570c1e2005-08-25 16:25:52 -0700789/**
790 * xprt_complete_rqst - called when reply processing is complete
791 * @task: RPC request that recently completed
792 * @copied: actual number of bytes received from the transport
793 *
794 * Caller holds transport lock.
795 */
796void xprt_complete_rqst(struct rpc_task *task, int copied)
797{
798 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustfda13932008-02-22 16:34:12 -0500799 struct rpc_xprt *xprt = req->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
Chuck Lever1570c1e2005-08-25 16:25:52 -0700801 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
802 task->tk_pid, ntohl(req->rq_xid), copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
Trond Myklebustfda13932008-02-22 16:34:12 -0500804 xprt->stat.recvs++;
Chuck Leveref759a22006-03-20 13:44:17 -0500805 task->tk_rtt = (long)jiffies - req->rq_xtime;
806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 list_del_init(&req->rq_list);
Trond Myklebust1e799b62008-03-21 16:19:41 -0400808 req->rq_private_buf.len = copied;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400809 /* Ensure all writes are done before we update */
810 /* req->rq_reply_bytes_recvd */
Trond Myklebust43ac3f22006-03-20 13:44:51 -0500811 smp_wmb();
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400812 req->rq_reply_bytes_recvd = copied;
Trond Myklebustfda13932008-02-22 16:34:12 -0500813 rpc_wake_up_queued_task(&xprt->pending, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400815EXPORT_SYMBOL_GPL(xprt_complete_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816
Chuck Lever46c0ee82005-08-25 16:25:52 -0700817static void xprt_timer(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700819 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 struct rpc_xprt *xprt = req->rq_xprt;
821
Trond Myklebust5d008372008-02-22 16:34:17 -0500822 if (task->tk_status != -ETIMEDOUT)
823 return;
Chuck Lever46121cf2007-01-31 12:14:08 -0500824 dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
Chuck Lever46c0ee82005-08-25 16:25:52 -0700825
Trond Myklebust5d008372008-02-22 16:34:17 -0500826 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400827 if (!req->rq_reply_bytes_recvd) {
Chuck Lever46c0ee82005-08-25 16:25:52 -0700828 if (xprt->ops->timer)
829 xprt->ops->timer(task);
Trond Myklebust5d008372008-02-22 16:34:17 -0500830 } else
831 task->tk_status = 0;
832 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833}
834
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300835static inline int xprt_has_timer(struct rpc_xprt *xprt)
836{
837 return xprt->idle_timeout != 0;
838}
839
Chuck Lever9903cd12005-08-11 16:25:26 -0400840/**
841 * xprt_prepare_transmit - reserve the transport before sending a request
842 * @task: RPC task about to send a request
843 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 */
Chuck Lever9903cd12005-08-11 16:25:26 -0400845int xprt_prepare_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846{
847 struct rpc_rqst *req = task->tk_rqstp;
848 struct rpc_xprt *xprt = req->rq_xprt;
849 int err = 0;
850
Chuck Lever46121cf2007-01-31 12:14:08 -0500851 dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400853 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400854 if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) {
855 err = req->rq_reply_bytes_recvd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 goto out_unlock;
857 }
Trond Myklebust2a491992009-03-11 14:38:00 -0400858 if (!xprt->ops->reserve_xprt(task))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 err = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860out_unlock:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400861 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 return err;
863}
864
Trond Myklebuste0ab53d2006-07-27 17:22:50 -0400865void xprt_end_transmit(struct rpc_task *task)
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700866{
Rahul Iyer343952f2009-04-01 09:23:17 -0400867 xprt_release_write(task->tk_rqstp->rq_xprt, task);
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700868}
869
Chuck Lever9903cd12005-08-11 16:25:26 -0400870/**
871 * xprt_transmit - send an RPC request on a transport
872 * @task: controlling RPC task
873 *
874 * We have to copy the iovec because sendmsg fiddles with its contents.
875 */
876void xprt_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 struct rpc_rqst *req = task->tk_rqstp;
879 struct rpc_xprt *xprt = req->rq_xprt;
Chuck Levera246b012005-08-11 16:25:23 -0400880 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
Chuck Lever46121cf2007-01-31 12:14:08 -0500882 dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400884 if (!req->rq_reply_bytes_recvd) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400885 if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
886 /*
887 * Add to the list only if we're expecting a reply
888 */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400889 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 /* Update the softirq receive buffer */
891 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
892 sizeof(req->rq_private_buf));
893 /* Add request to the receive list */
894 list_add_tail(&req->rq_list, &xprt->recv);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400895 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 xprt_reset_majortimeo(req);
Trond Myklebust0f9dc2b2005-06-22 17:16:28 +0000897 /* Turn off autodisconnect */
898 del_singleshot_timer_sync(&xprt->timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 }
900 } else if (!req->rq_bytes_sent)
901 return;
902
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400903 req->rq_connect_cookie = xprt->connect_cookie;
Chuck Leverb22602a2008-06-06 13:22:25 -0400904 req->rq_xtime = jiffies;
Chuck Levera246b012005-08-11 16:25:23 -0400905 status = xprt->ops->send_request(task);
Trond Myklebustc8485e42009-03-11 14:37:59 -0400906 if (status != 0) {
907 task->tk_status = status;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700908 return;
909 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
Trond Myklebustc8485e42009-03-11 14:37:59 -0400911 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
912 spin_lock_bh(&xprt->transport_lock);
913
914 xprt->ops->set_retrans_timeout(task);
915
916 xprt->stat.sends++;
917 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
918 xprt->stat.bklog_u += xprt->backlog.qlen;
919
920 /* Don't race with disconnect */
921 if (!xprt_connected(xprt))
922 task->tk_status = -ENOTCONN;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400923 else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400924 /*
925 * Sleep on the pending queue since
926 * we're expecting a reply.
927 */
Trond Myklebustc8485e42009-03-11 14:37:59 -0400928 rpc_sleep_on(&xprt->pending, task, xprt_timer);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400929 }
Trond Myklebustc8485e42009-03-11 14:37:59 -0400930 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931}
932
Chuck Lever9903cd12005-08-11 16:25:26 -0400933static inline void do_xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934{
935 struct rpc_xprt *xprt = task->tk_xprt;
936
937 task->tk_status = 0;
938 if (task->tk_rqstp)
939 return;
940 if (!list_empty(&xprt->free)) {
941 struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
942 list_del_init(&req->rq_list);
943 task->tk_rqstp = req;
944 xprt_request_init(task, xprt);
945 return;
946 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500947 dprintk("RPC: waiting for request slot\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 task->tk_status = -EAGAIN;
949 task->tk_timeout = 0;
Trond Myklebust5d008372008-02-22 16:34:17 -0500950 rpc_sleep_on(&xprt->backlog, task, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951}
952
Chuck Lever9903cd12005-08-11 16:25:26 -0400953/**
954 * xprt_reserve - allocate an RPC request slot
955 * @task: RPC task requesting a slot allocation
956 *
957 * If no more slots are available, place the task on the transport's
958 * backlog queue.
959 */
960void xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961{
962 struct rpc_xprt *xprt = task->tk_xprt;
963
964 task->tk_status = -EIO;
Trond Myklebust0065db32006-01-03 09:55:56 +0100965 spin_lock(&xprt->reserve_lock);
966 do_xprt_reserve(task);
967 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968}
969
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700970static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971{
972 return xprt->xid++;
973}
974
975static inline void xprt_init_xid(struct rpc_xprt *xprt)
976{
Chuck Leverbf3fcf82006-05-25 01:40:51 -0400977 xprt->xid = net_random();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978}
979
Chuck Lever9903cd12005-08-11 16:25:26 -0400980static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981{
982 struct rpc_rqst *req = task->tk_rqstp;
983
Trond Myklebustba7392b2007-12-20 16:03:55 -0500984 req->rq_timeout = task->tk_client->cl_timeout->to_initval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 req->rq_task = task;
986 req->rq_xprt = xprt;
Chuck Lever02107142006-01-03 09:55:49 +0100987 req->rq_buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 req->rq_xid = xprt_alloc_xid(xprt);
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -0400989 req->rq_release_snd_buf = NULL;
Trond Myklebustda458282006-08-31 15:44:52 -0400990 xprt_reset_majortimeo(req);
Chuck Lever46121cf2007-01-31 12:14:08 -0500991 dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 req, ntohl(req->rq_xid));
993}
994
Chuck Lever9903cd12005-08-11 16:25:26 -0400995/**
996 * xprt_release - release an RPC request slot
997 * @task: task which is finished with the slot
998 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 */
Chuck Lever9903cd12005-08-11 16:25:26 -04001000void xprt_release(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001{
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001002 struct rpc_xprt *xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 struct rpc_rqst *req;
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001004 int is_bc_request;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005
1006 if (!(req = task->tk_rqstp))
1007 return;
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001008
1009 /* Preallocated backchannel request? */
1010 is_bc_request = bc_prealloc(req);
1011
1012 xprt = req->rq_xprt;
Chuck Lever11c556b2006-03-20 13:44:22 -05001013 rpc_count_iostats(task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001014 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -07001015 xprt->ops->release_xprt(xprt, task);
Chuck Levera58dd392005-08-25 16:25:53 -07001016 if (xprt->ops->release_request)
1017 xprt->ops->release_request(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 if (!list_empty(&req->rq_list))
1019 list_del(&req->rq_list);
1020 xprt->last_used = jiffies;
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001021 if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
Chuck Levera246b012005-08-11 16:25:23 -04001022 mod_timer(&xprt->timer,
Chuck Lever03bf4b72005-08-25 16:25:55 -07001023 xprt->last_used + xprt->idle_timeout);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001024 spin_unlock_bh(&xprt->transport_lock);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001025 if (!bc_prealloc(req))
1026 xprt->ops->buf_free(req->rq_buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 task->tk_rqstp = NULL;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001028 if (req->rq_release_snd_buf)
1029 req->rq_release_snd_buf(req);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001030
1031 /*
1032 * Early exit if this is a backchannel preallocated request.
1033 * There is no need to have it added to the RPC slot list.
1034 */
1035 if (is_bc_request)
1036 return;
1037
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 memset(req, 0, sizeof(*req)); /* mark unused */
1039
Chuck Lever46121cf2007-01-31 12:14:08 -05001040 dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
Chuck Lever5dc07722005-08-11 16:25:35 -04001042 spin_lock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 list_add(&req->rq_list, &xprt->free);
Chuck Lever555ee3a2005-08-25 16:25:54 -07001044 rpc_wake_up_next(&xprt->backlog);
Chuck Lever5dc07722005-08-11 16:25:35 -04001045 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046}
1047
Chuck Lever9903cd12005-08-11 16:25:26 -04001048/**
Chuck Leverc2866762006-08-22 20:06:20 -04001049 * xprt_create_transport - create an RPC transport
Frank van Maarseveen96802a02007-07-08 13:08:54 +02001050 * @args: rpc transport creation arguments
Chuck Leverc2866762006-08-22 20:06:20 -04001051 *
1052 */
\"Talpey, Thomas\3c341b0b2007-09-10 13:47:07 -04001053struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
Chuck Leverc2866762006-08-22 20:06:20 -04001054{
Chuck Leverc2866762006-08-22 20:06:20 -04001055 struct rpc_xprt *xprt;
1056 struct rpc_rqst *req;
\"Talpey, Thomas\bc255712007-09-10 13:46:39 -04001057 struct xprt_class *t;
Chuck Leverc2866762006-08-22 20:06:20 -04001058
\"Talpey, Thomas\bc255712007-09-10 13:46:39 -04001059 spin_lock(&xprt_list_lock);
1060 list_for_each_entry(t, &xprt_list, list) {
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -04001061 if (t->ident == args->ident) {
\"Talpey, Thomas\bc255712007-09-10 13:46:39 -04001062 spin_unlock(&xprt_list_lock);
1063 goto found;
1064 }
Chuck Leverc2866762006-08-22 20:06:20 -04001065 }
\"Talpey, Thomas\bc255712007-09-10 13:46:39 -04001066 spin_unlock(&xprt_list_lock);
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -04001067 printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
\"Talpey, Thomas\bc255712007-09-10 13:46:39 -04001068 return ERR_PTR(-EIO);
1069
1070found:
1071 xprt = t->setup(args);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001072 if (IS_ERR(xprt)) {
Chuck Lever46121cf2007-01-31 12:14:08 -05001073 dprintk("RPC: xprt_create_transport: failed, %ld\n",
Chuck Leverc8541ec2006-10-17 14:44:27 -04001074 -PTR_ERR(xprt));
1075 return xprt;
Chuck Leverc2866762006-08-22 20:06:20 -04001076 }
1077
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001078 kref_init(&xprt->kref);
Chuck Leverc2866762006-08-22 20:06:20 -04001079 spin_lock_init(&xprt->transport_lock);
1080 spin_lock_init(&xprt->reserve_lock);
1081
1082 INIT_LIST_HEAD(&xprt->free);
1083 INIT_LIST_HEAD(&xprt->recv);
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001084#if defined(CONFIG_NFS_V4_1)
1085 spin_lock_init(&xprt->bc_pa_lock);
1086 INIT_LIST_HEAD(&xprt->bc_pa_list);
1087#endif /* CONFIG_NFS_V4_1 */
1088
David Howells65f27f32006-11-22 14:55:48 +00001089 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001090 if (xprt_has_timer(xprt))
1091 setup_timer(&xprt->timer, xprt_init_autodisconnect,
1092 (unsigned long)xprt);
1093 else
1094 init_timer(&xprt->timer);
Chuck Leverc2866762006-08-22 20:06:20 -04001095 xprt->last_used = jiffies;
1096 xprt->cwnd = RPC_INITCWND;
Chuck Levera5090502007-03-29 16:48:04 -04001097 xprt->bind_index = 0;
Chuck Leverc2866762006-08-22 20:06:20 -04001098
1099 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
1100 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
1101 rpc_init_wait_queue(&xprt->sending, "xprt_sending");
1102 rpc_init_wait_queue(&xprt->resend, "xprt_resend");
1103 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1104
1105 /* initialize free list */
1106 for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--)
1107 list_add(&req->rq_list, &xprt->free);
1108
1109 xprt_init_xid(xprt);
1110
Chuck Lever46121cf2007-01-31 12:14:08 -05001111 dprintk("RPC: created transport %p with %u slots\n", xprt,
Chuck Leverc2866762006-08-22 20:06:20 -04001112 xprt->max_reqs);
Chuck Leverc2866762006-08-22 20:06:20 -04001113 return xprt;
1114}
1115
Chuck Lever9903cd12005-08-11 16:25:26 -04001116/**
1117 * xprt_destroy - destroy an RPC transport, killing off all requests.
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001118 * @kref: kref for the transport to destroy
Chuck Lever9903cd12005-08-11 16:25:26 -04001119 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 */
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001121static void xprt_destroy(struct kref *kref)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122{
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001123 struct rpc_xprt *xprt = container_of(kref, struct rpc_xprt, kref);
1124
Chuck Lever46121cf2007-01-31 12:14:08 -05001125 dprintk("RPC: destroying transport %p\n", xprt);
Trond Myklebust0065db32006-01-03 09:55:56 +01001126 xprt->shutdown = 1;
1127 del_timer_sync(&xprt->timer);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001128
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001129 rpc_destroy_wait_queue(&xprt->binding);
1130 rpc_destroy_wait_queue(&xprt->pending);
1131 rpc_destroy_wait_queue(&xprt->sending);
1132 rpc_destroy_wait_queue(&xprt->resend);
1133 rpc_destroy_wait_queue(&xprt->backlog);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001134 /*
1135 * Tear down transport state and free the rpc_xprt
1136 */
Chuck Levera246b012005-08-11 16:25:23 -04001137 xprt->ops->destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001138}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001140/**
1141 * xprt_put - release a reference to an RPC transport.
1142 * @xprt: pointer to the transport
1143 *
1144 */
1145void xprt_put(struct rpc_xprt *xprt)
1146{
1147 kref_put(&xprt->kref, xprt_destroy);
1148}
1149
1150/**
1151 * xprt_get - return a reference to an RPC transport.
1152 * @xprt: pointer to the transport
1153 *
1154 */
1155struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
1156{
1157 kref_get(&xprt->kref);
1158 return xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159}