blob: 095363eee764b3ff496a745f56e4fa646f5f02c0 [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 Lever555ee3a2005-08-25 16:25:54 -070074/*
75 * The transport code maintains an estimate on the maximum number of out-
76 * standing RPC requests, using a smoothed version of the congestion
77 * avoidance implemented in 44BSD. This is basically the Van Jacobson
78 * congestion algorithm: If a retransmit occurs, the congestion window is
79 * halved; otherwise, it is incremented by 1/cwnd when
80 *
81 * - a reply is received and
82 * - a full number of requests are outstanding and
83 * - the congestion window hasn't been updated recently.
84 */
85#define RPC_CWNDSHIFT (8U)
86#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
87#define RPC_INITCWND RPC_CWNDSCALE
88#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
89
90#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Chuck Lever12a80462005-08-25 16:25:51 -070092/**
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040093 * xprt_register_transport - register a transport implementation
94 * @transport: transport to register
95 *
96 * If a transport implementation is loaded as a kernel module, it can
97 * call this interface to make itself known to the RPC client.
98 *
99 * Returns:
100 * 0: transport successfully registered
101 * -EEXIST: transport already registered
102 * -EINVAL: transport module being unloaded
103 */
104int xprt_register_transport(struct xprt_class *transport)
105{
106 struct xprt_class *t;
107 int result;
108
109 result = -EEXIST;
110 spin_lock(&xprt_list_lock);
111 list_for_each_entry(t, &xprt_list, list) {
112 /* don't register the same transport class twice */
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -0400113 if (t->ident == transport->ident)
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400114 goto out;
115 }
116
Denis V. Lunevc9f6cde2008-07-31 09:53:56 +0400117 list_add_tail(&transport->list, &xprt_list);
118 printk(KERN_INFO "RPC: Registered %s transport module.\n",
119 transport->name);
120 result = 0;
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400121
122out:
123 spin_unlock(&xprt_list_lock);
124 return result;
125}
126EXPORT_SYMBOL_GPL(xprt_register_transport);
127
128/**
129 * xprt_unregister_transport - unregister a transport implementation
Randy Dunlap65b6e422008-02-13 15:03:23 -0800130 * @transport: transport to unregister
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400131 *
132 * Returns:
133 * 0: transport successfully unregistered
134 * -ENOENT: transport never registered
135 */
136int xprt_unregister_transport(struct xprt_class *transport)
137{
138 struct xprt_class *t;
139 int result;
140
141 result = 0;
142 spin_lock(&xprt_list_lock);
143 list_for_each_entry(t, &xprt_list, list) {
144 if (t == transport) {
145 printk(KERN_INFO
146 "RPC: Unregistered %s transport module.\n",
147 transport->name);
148 list_del_init(&transport->list);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400149 goto out;
150 }
151 }
152 result = -ENOENT;
153
154out:
155 spin_unlock(&xprt_list_lock);
156 return result;
157}
158EXPORT_SYMBOL_GPL(xprt_unregister_transport);
159
160/**
Tom Talpey441e3e22009-03-11 14:37:56 -0400161 * xprt_load_transport - load a transport implementation
162 * @transport_name: transport to load
163 *
164 * Returns:
165 * 0: transport successfully loaded
166 * -ENOENT: transport module not available
167 */
168int xprt_load_transport(const char *transport_name)
169{
170 struct xprt_class *t;
Tom Talpey441e3e22009-03-11 14:37:56 -0400171 int result;
172
173 result = 0;
174 spin_lock(&xprt_list_lock);
175 list_for_each_entry(t, &xprt_list, list) {
176 if (strcmp(t->name, transport_name) == 0) {
177 spin_unlock(&xprt_list_lock);
178 goto out;
179 }
180 }
181 spin_unlock(&xprt_list_lock);
Alex Riesenef7ffe82010-05-24 14:33:05 -0700182 result = request_module("xprt%s", transport_name);
Tom Talpey441e3e22009-03-11 14:37:56 -0400183out:
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
Randy Dunlap177c27b2011-07-28 06:54:36 +0000191 * @xprt: pointer to the target transport
Chuck Lever12a80462005-08-25 16:25:51 -0700192 *
193 * This prevents mixing the payload of separate requests, and prevents
194 * transport connects from colliding with writes. No congestion control
195 * is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400197int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198{
Chuck Lever12a80462005-08-25 16:25:51 -0700199 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400200 int priority;
Chuck Lever12a80462005-08-25 16:25:51 -0700201
202 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
203 if (task == xprt->snd_task)
204 return 1;
Chuck Lever12a80462005-08-25 16:25:51 -0700205 goto out_sleep;
206 }
207 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400208 if (req != NULL) {
209 req->rq_bytes_sent = 0;
210 req->rq_ntrans++;
211 }
j223yang@asset.uwaterloo.ca4d4a76f2011-03-10 12:40:28 -0500212
Chuck Lever12a80462005-08-25 16:25:51 -0700213 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;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400220 if (req == NULL)
221 priority = RPC_PRIORITY_LOW;
222 else if (!req->rq_ntrans)
223 priority = RPC_PRIORITY_NORMAL;
Chuck Lever12a80462005-08-25 16:25:51 -0700224 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400225 priority = RPC_PRIORITY_HIGH;
226 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Chuck Lever12a80462005-08-25 16:25:51 -0700227 return 0;
228}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400229EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
Chuck Lever12a80462005-08-25 16:25:51 -0700230
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100231static void xprt_clear_locked(struct rpc_xprt *xprt)
232{
233 xprt->snd_task = NULL;
Trond Myklebustd19751e2012-09-11 17:21:25 -0400234 if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100235 smp_mb__before_clear_bit();
236 clear_bit(XPRT_LOCKED, &xprt->state);
237 smp_mb__after_clear_bit();
238 } else
Trond Myklebustc1384c92007-06-14 18:00:42 -0400239 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100240}
241
Chuck Lever12a80462005-08-25 16:25:51 -0700242/*
243 * xprt_reserve_xprt_cong - serialize write access to transports
244 * @task: task that is requesting access to the transport
245 *
246 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
247 * integrated into the decision of whether a request is allowed to be
248 * woken up and given access to the transport.
249 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400250int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
Chuck Lever12a80462005-08-25 16:25:51 -0700251{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400253 int priority;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Chuck Lever2226feb2005-08-11 16:25:38 -0400255 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 if (task == xprt->snd_task)
257 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 goto out_sleep;
259 }
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400260 if (req == NULL) {
261 xprt->snd_task = task;
262 return 1;
263 }
Chuck Lever12a80462005-08-25 16:25:51 -0700264 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400266 req->rq_bytes_sent = 0;
267 req->rq_ntrans++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 return 1;
269 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100270 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500272 dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 task->tk_timeout = 0;
274 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400275 if (req == NULL)
276 priority = RPC_PRIORITY_LOW;
277 else if (!req->rq_ntrans)
278 priority = RPC_PRIORITY_NORMAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400280 priority = RPC_PRIORITY_HIGH;
281 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 return 0;
283}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400284EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Chuck Lever12a80462005-08-25 16:25:51 -0700286static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
288 int retval;
289
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400290 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400291 retval = xprt->ops->reserve_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400292 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 return retval;
294}
295
Trond Myklebust961a8282012-01-17 22:57:37 -0500296static bool __xprt_lock_write_func(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297{
Trond Myklebust961a8282012-01-17 22:57:37 -0500298 struct rpc_xprt *xprt = data;
Chuck Lever49e9a892005-08-25 16:25:51 -0700299 struct rpc_rqst *req;
300
Chuck Lever49e9a892005-08-25 16:25:51 -0700301 req = task->tk_rqstp;
302 xprt->snd_task = task;
303 if (req) {
304 req->rq_bytes_sent = 0;
305 req->rq_ntrans++;
306 }
Trond Myklebust961a8282012-01-17 22:57:37 -0500307 return true;
308}
Chuck Lever49e9a892005-08-25 16:25:51 -0700309
Trond Myklebust961a8282012-01-17 22:57:37 -0500310static void __xprt_lock_write_next(struct rpc_xprt *xprt)
311{
312 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
313 return;
314
315 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt))
316 return;
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100317 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700318}
319
Trond Myklebust961a8282012-01-17 22:57:37 -0500320static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data)
Chuck Lever49e9a892005-08-25 16:25:51 -0700321{
Trond Myklebust961a8282012-01-17 22:57:37 -0500322 struct rpc_xprt *xprt = data;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400323 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400325 req = task->tk_rqstp;
326 if (req == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 xprt->snd_task = task;
Trond Myklebust961a8282012-01-17 22:57:37 -0500328 return true;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400329 }
330 if (__xprt_get_cong(xprt, task)) {
331 xprt->snd_task = task;
332 req->rq_bytes_sent = 0;
333 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500334 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 }
Trond Myklebust961a8282012-01-17 22:57:37 -0500336 return false;
337}
338
339static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
340{
341 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
342 return;
343 if (RPCXPRT_CONGESTED(xprt))
344 goto out_unlock;
345 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt))
346 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100348 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349}
350
Chuck Lever49e9a892005-08-25 16:25:51 -0700351/**
352 * xprt_release_xprt - allow other requests to use a transport
353 * @xprt: transport with other tasks potentially waiting
354 * @task: task that is releasing access to the transport
355 *
356 * Note that "task" can be NULL. No congestion control is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 */
Chuck Lever49e9a892005-08-25 16:25:51 -0700358void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
360 if (xprt->snd_task == task) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100361 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 __xprt_lock_write_next(xprt);
363 }
364}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400365EXPORT_SYMBOL_GPL(xprt_release_xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
Chuck Lever49e9a892005-08-25 16:25:51 -0700367/**
368 * xprt_release_xprt_cong - allow other requests to use a transport
369 * @xprt: transport with other tasks potentially waiting
370 * @task: task that is releasing access to the transport
371 *
372 * Note that "task" can be NULL. Another task is awoken to use the
373 * transport if the transport's congestion window allows it.
374 */
375void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
376{
377 if (xprt->snd_task == task) {
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100378 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700379 __xprt_lock_write_next_cong(xprt);
380 }
381}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400382EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
Chuck Lever49e9a892005-08-25 16:25:51 -0700383
384static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400386 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -0700387 xprt->ops->release_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400388 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389}
390
391/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 * Van Jacobson congestion avoidance. Check if the congestion window
393 * overflowed. Put the task to sleep if this is the case.
394 */
395static int
396__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
397{
398 struct rpc_rqst *req = task->tk_rqstp;
399
400 if (req->rq_cong)
401 return 1;
Chuck Lever46121cf2007-01-31 12:14:08 -0500402 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 task->tk_pid, xprt->cong, xprt->cwnd);
404 if (RPCXPRT_CONGESTED(xprt))
405 return 0;
406 req->rq_cong = 1;
407 xprt->cong += RPC_CWNDSCALE;
408 return 1;
409}
410
411/*
412 * Adjust the congestion window, and wake up the next task
413 * that has been sleeping due to congestion
414 */
415static void
416__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
417{
418 if (!req->rq_cong)
419 return;
420 req->rq_cong = 0;
421 xprt->cong -= RPC_CWNDSCALE;
Chuck Lever49e9a892005-08-25 16:25:51 -0700422 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423}
424
Chuck Lever46c0ee82005-08-25 16:25:52 -0700425/**
Chuck Levera58dd392005-08-25 16:25:53 -0700426 * xprt_release_rqst_cong - housekeeping when request is complete
427 * @task: RPC request that recently completed
428 *
429 * Useful for transports that require congestion control.
430 */
431void xprt_release_rqst_cong(struct rpc_task *task)
432{
Trond Myklebusta4f08352013-01-08 09:10:21 -0500433 struct rpc_rqst *req = task->tk_rqstp;
434
435 __xprt_put_cong(req->rq_xprt, req);
Chuck Levera58dd392005-08-25 16:25:53 -0700436}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400437EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
Chuck Levera58dd392005-08-25 16:25:53 -0700438
439/**
Chuck Lever46c0ee82005-08-25 16:25:52 -0700440 * xprt_adjust_cwnd - adjust transport congestion window
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500441 * @xprt: pointer to xprt
Chuck Lever46c0ee82005-08-25 16:25:52 -0700442 * @task: recently completed RPC request used to adjust window
443 * @result: result code of completed RPC request
444 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
446 */
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500447void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700449 struct rpc_rqst *req = task->tk_rqstp;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700450 unsigned long cwnd = xprt->cwnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 if (result >= 0 && cwnd <= xprt->cong) {
453 /* The (cwnd >> 1) term makes sure
454 * the result gets rounded properly. */
455 cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
456 if (cwnd > RPC_MAXCWND(xprt))
457 cwnd = RPC_MAXCWND(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700458 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 } else if (result == -ETIMEDOUT) {
460 cwnd >>= 1;
461 if (cwnd < RPC_CWNDSCALE)
462 cwnd = RPC_CWNDSCALE;
463 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500464 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 xprt->cong, xprt->cwnd, cwnd);
466 xprt->cwnd = cwnd;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700467 __xprt_put_cong(xprt, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400469EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
Chuck Lever44fbac22005-08-11 16:25:44 -0400471/**
472 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
473 * @xprt: transport with waiting tasks
474 * @status: result code to plant in each task before waking it
475 *
476 */
477void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
478{
479 if (status < 0)
480 rpc_wake_up_status(&xprt->pending, status);
481 else
482 rpc_wake_up(&xprt->pending);
483}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400484EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
Chuck Lever44fbac22005-08-11 16:25:44 -0400485
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400486/**
487 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
488 * @task: task to be put to sleep
Randy Dunlap0b80ae42008-04-26 22:59:02 -0700489 * @action: function pointer to be executed after wait
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500490 *
491 * Note that we only set the timer for the case of RPC_IS_SOFT(), since
492 * we don't in general want to force a socket disconnection due to
493 * an incomplete RPC call transmission.
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400494 */
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400495void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400496{
497 struct rpc_rqst *req = task->tk_rqstp;
498 struct rpc_xprt *xprt = req->rq_xprt;
499
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500500 task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0;
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400501 rpc_sleep_on(&xprt->pending, task, action);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400502}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400503EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400504
505/**
506 * xprt_write_space - wake the task waiting for transport output buffer space
507 * @xprt: transport with waiting tasks
508 *
509 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
510 */
511void xprt_write_space(struct rpc_xprt *xprt)
512{
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400513 spin_lock_bh(&xprt->transport_lock);
514 if (xprt->snd_task) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500515 dprintk("RPC: write space: waking waiting task on "
516 "xprt %p\n", xprt);
Trond Myklebustfda13932008-02-22 16:34:12 -0500517 rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400518 }
519 spin_unlock_bh(&xprt->transport_lock);
520}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400521EXPORT_SYMBOL_GPL(xprt_write_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400522
Chuck Leverfe3aca22005-08-25 16:25:50 -0700523/**
524 * xprt_set_retrans_timeout_def - set a request's retransmit timeout
525 * @task: task whose timeout is to be set
526 *
527 * Set a request's retransmit timeout based on the transport's
528 * default timeout parameters. Used by transports that don't adjust
529 * the retransmit timeout based on round-trip time estimation.
530 */
531void xprt_set_retrans_timeout_def(struct rpc_task *task)
532{
533 task->tk_timeout = task->tk_rqstp->rq_timeout;
534}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400535EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700536
Ben Hutchings2c530402012-07-10 10:55:09 +0000537/**
Chuck Leverfe3aca22005-08-25 16:25:50 -0700538 * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
539 * @task: task whose timeout is to be set
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800540 *
Chuck Leverfe3aca22005-08-25 16:25:50 -0700541 * Set a request's retransmit timeout using the RTT estimator.
542 */
543void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
544{
545 int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500546 struct rpc_clnt *clnt = task->tk_client;
547 struct rpc_rtt *rtt = clnt->cl_rtt;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700548 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500549 unsigned long max_timeout = clnt->cl_timeout->to_maxval;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700550
551 task->tk_timeout = rpc_calc_rto(rtt, timer);
552 task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
553 if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
554 task->tk_timeout = max_timeout;
555}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400556EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700557
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558static void xprt_reset_majortimeo(struct rpc_rqst *req)
559{
Trond Myklebustba7392b2007-12-20 16:03:55 -0500560 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
562 req->rq_majortimeo = req->rq_timeout;
563 if (to->to_exponential)
564 req->rq_majortimeo <<= to->to_retries;
565 else
566 req->rq_majortimeo += to->to_increment * to->to_retries;
567 if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
568 req->rq_majortimeo = to->to_maxval;
569 req->rq_majortimeo += jiffies;
570}
571
Chuck Lever9903cd12005-08-11 16:25:26 -0400572/**
573 * xprt_adjust_timeout - adjust timeout values for next retransmit
574 * @req: RPC request containing parameters to use for the adjustment
575 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 */
577int xprt_adjust_timeout(struct rpc_rqst *req)
578{
579 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500580 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 int status = 0;
582
583 if (time_before(jiffies, req->rq_majortimeo)) {
584 if (to->to_exponential)
585 req->rq_timeout <<= 1;
586 else
587 req->rq_timeout += to->to_increment;
588 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
589 req->rq_timeout = to->to_maxval;
590 req->rq_retries++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 } else {
592 req->rq_timeout = to->to_initval;
593 req->rq_retries = 0;
594 xprt_reset_majortimeo(req);
595 /* Reset the RTT counters == "slow start" */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400596 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400598 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 status = -ETIMEDOUT;
600 }
601
602 if (req->rq_timeout == 0) {
603 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
604 req->rq_timeout = 5 * HZ;
605 }
606 return status;
607}
608
David Howells65f27f32006-11-22 14:55:48 +0000609static void xprt_autoclose(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610{
David Howells65f27f32006-11-22 14:55:48 +0000611 struct rpc_xprt *xprt =
612 container_of(work, struct rpc_xprt, task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
Chuck Levera246b012005-08-11 16:25:23 -0400614 xprt->ops->close(xprt);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500615 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 xprt_release_write(xprt, NULL);
617}
618
Chuck Lever9903cd12005-08-11 16:25:26 -0400619/**
Trond Myklebust62da3b22007-11-06 18:44:20 -0500620 * xprt_disconnect_done - mark a transport as disconnected
Chuck Lever9903cd12005-08-11 16:25:26 -0400621 * @xprt: transport to flag for disconnect
622 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 */
Trond Myklebust62da3b22007-11-06 18:44:20 -0500624void xprt_disconnect_done(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625{
Chuck Lever46121cf2007-01-31 12:14:08 -0500626 dprintk("RPC: disconnected transport %p\n", xprt);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400627 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 xprt_clear_connected(xprt);
Trond Myklebust2a491992009-03-11 14:38:00 -0400629 xprt_wake_pending_tasks(xprt, -EAGAIN);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400630 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631}
Trond Myklebust62da3b22007-11-06 18:44:20 -0500632EXPORT_SYMBOL_GPL(xprt_disconnect_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Trond Myklebust66af1e52007-11-06 10:18:36 -0500634/**
635 * xprt_force_disconnect - force a transport to disconnect
636 * @xprt: transport to disconnect
637 *
638 */
639void xprt_force_disconnect(struct rpc_xprt *xprt)
640{
641 /* Don't race with the test_bit() in xprt_clear_locked() */
642 spin_lock_bh(&xprt->transport_lock);
643 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
644 /* Try to schedule an autoclose RPC call */
645 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
646 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400647 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500648 spin_unlock_bh(&xprt->transport_lock);
649}
Trond Myklebust66af1e52007-11-06 10:18:36 -0500650
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400651/**
652 * xprt_conditional_disconnect - force a transport to disconnect
653 * @xprt: transport to disconnect
654 * @cookie: 'connection cookie'
655 *
656 * This attempts to break the connection if and only if 'cookie' matches
657 * the current transport 'connection cookie'. It ensures that we don't
658 * try to break the connection more than once when we need to retransmit
659 * a batch of RPC requests.
660 *
661 */
662void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
663{
664 /* Don't race with the test_bit() in xprt_clear_locked() */
665 spin_lock_bh(&xprt->transport_lock);
666 if (cookie != xprt->connect_cookie)
667 goto out;
668 if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
669 goto out;
670 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
671 /* Try to schedule an autoclose RPC call */
672 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
673 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400674 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400675out:
676 spin_unlock_bh(&xprt->transport_lock);
677}
678
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679static void
680xprt_init_autodisconnect(unsigned long data)
681{
682 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
683
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400684 spin_lock(&xprt->transport_lock);
Trond Myklebustd19751e2012-09-11 17:21:25 -0400685 if (!list_empty(&xprt->recv))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 goto out_abort;
Chuck Lever2226feb2005-08-11 16:25:38 -0400687 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 goto out_abort;
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400689 spin_unlock(&xprt->transport_lock);
Trond Myklebustf75e6742009-04-21 17:18:20 -0400690 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
691 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 return;
693out_abort:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400694 spin_unlock(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695}
696
Chuck Lever9903cd12005-08-11 16:25:26 -0400697/**
698 * xprt_connect - schedule a transport connect operation
699 * @task: RPC task that is requesting the connect
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 *
701 */
702void xprt_connect(struct rpc_task *task)
703{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500704 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
Chuck Lever46121cf2007-01-31 12:14:08 -0500706 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 xprt, (xprt_connected(xprt) ? "is" : "is not"));
708
Chuck Leverec739ef2006-08-22 20:06:15 -0400709 if (!xprt_bound(xprt)) {
Trond Myklebust01d37c42009-03-11 14:09:39 -0400710 task->tk_status = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 return;
712 }
713 if (!xprt_lock_write(xprt, task))
714 return;
Trond Myklebustfeb8ca32009-12-03 08:10:17 -0500715
716 if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
717 xprt->ops->close(xprt);
718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 if (xprt_connected(xprt))
Chuck Levera246b012005-08-11 16:25:23 -0400720 xprt_release_write(xprt, task);
721 else {
Dan Carpenter87e3c052012-02-01 10:46:20 +0300722 task->tk_rqstp->rq_bytes_sent = 0;
Trond Myklebusta8ce4a82010-04-16 16:42:12 -0400723 task->tk_timeout = task->tk_rqstp->rq_timeout;
Trond Myklebust5d008372008-02-22 16:34:17 -0500724 rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
Trond Myklebust0b9e7942010-04-16 16:41:57 -0400725
726 if (test_bit(XPRT_CLOSING, &xprt->state))
727 return;
728 if (xprt_test_and_set_connecting(xprt))
729 return;
Chuck Lever262ca072006-03-20 13:44:16 -0500730 xprt->stat.connect_start = jiffies;
Trond Myklebust1b092092013-01-08 09:26:49 -0500731 xprt->ops->connect(xprt, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733}
734
Chuck Lever9903cd12005-08-11 16:25:26 -0400735static void xprt_connect_status(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500737 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
Chuck Levercd983ef2008-06-11 17:56:13 -0400739 if (task->tk_status == 0) {
Chuck Lever262ca072006-03-20 13:44:16 -0500740 xprt->stat.connect_count++;
741 xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
Chuck Lever46121cf2007-01-31 12:14:08 -0500742 dprintk("RPC: %5u xprt_connect_status: connection established\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 task->tk_pid);
744 return;
745 }
746
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 switch (task->tk_status) {
Trond Myklebust2a491992009-03-11 14:38:00 -0400748 case -EAGAIN:
749 dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
Chuck Lever23475d62005-08-11 16:25:08 -0400750 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 case -ETIMEDOUT:
Chuck Lever46121cf2007-01-31 12:14:08 -0500752 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
753 "out\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 break;
755 default:
Chuck Lever46121cf2007-01-31 12:14:08 -0500756 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
757 "server %s\n", task->tk_pid, -task->tk_status,
Trond Myklebust4e0038b2012-03-01 17:01:05 -0500758 xprt->servername);
Chuck Lever23475d62005-08-11 16:25:08 -0400759 xprt_release_write(xprt, task);
760 task->tk_status = -EIO;
Chuck Lever23475d62005-08-11 16:25:08 -0400761 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
Chuck Lever9903cd12005-08-11 16:25:26 -0400764/**
765 * xprt_lookup_rqst - find an RPC request corresponding to an XID
766 * @xprt: transport on which the original request was transmitted
767 * @xid: RPC XID of incoming reply
768 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700770struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771{
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400772 struct rpc_rqst *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400774 list_for_each_entry(entry, &xprt->recv, rq_list)
Chuck Lever262ca072006-03-20 13:44:16 -0500775 if (entry->rq_xid == xid)
776 return entry;
Chuck Lever46121cf2007-01-31 12:14:08 -0500777
778 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
779 ntohl(xid));
Chuck Lever262ca072006-03-20 13:44:16 -0500780 xprt->stat.bad_xids++;
781 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400783EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400785static void xprt_update_rtt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786{
Chuck Lever1570c1e2005-08-25 16:25:52 -0700787 struct rpc_rqst *req = task->tk_rqstp;
788 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
Eric Dumazet95c96172012-04-15 05:58:06 +0000789 unsigned int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400790 long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791
Chuck Lever1570c1e2005-08-25 16:25:52 -0700792 if (timer) {
793 if (req->rq_ntrans == 1)
Chuck Leverff839972010-05-07 13:34:47 -0400794 rpc_update_rtt(rtt, timer, m);
Chuck Lever1570c1e2005-08-25 16:25:52 -0700795 rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
Chuck Lever1570c1e2005-08-25 16:25:52 -0700797}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
Chuck Lever1570c1e2005-08-25 16:25:52 -0700799/**
800 * xprt_complete_rqst - called when reply processing is complete
801 * @task: RPC request that recently completed
802 * @copied: actual number of bytes received from the transport
803 *
804 * Caller holds transport lock.
805 */
806void xprt_complete_rqst(struct rpc_task *task, int copied)
807{
808 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustfda13932008-02-22 16:34:12 -0500809 struct rpc_xprt *xprt = req->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810
Chuck Lever1570c1e2005-08-25 16:25:52 -0700811 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
812 task->tk_pid, ntohl(req->rq_xid), copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813
Trond Myklebustfda13932008-02-22 16:34:12 -0500814 xprt->stat.recvs++;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400815 req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime);
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400816 if (xprt->ops->timer != NULL)
817 xprt_update_rtt(task);
Chuck Leveref759a22006-03-20 13:44:17 -0500818
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 list_del_init(&req->rq_list);
Trond Myklebust1e799b62008-03-21 16:19:41 -0400820 req->rq_private_buf.len = copied;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400821 /* Ensure all writes are done before we update */
822 /* req->rq_reply_bytes_recvd */
Trond Myklebust43ac3f22006-03-20 13:44:51 -0500823 smp_wmb();
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400824 req->rq_reply_bytes_recvd = copied;
Trond Myklebustfda13932008-02-22 16:34:12 -0500825 rpc_wake_up_queued_task(&xprt->pending, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400827EXPORT_SYMBOL_GPL(xprt_complete_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828
Chuck Lever46c0ee82005-08-25 16:25:52 -0700829static void xprt_timer(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700831 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 struct rpc_xprt *xprt = req->rq_xprt;
833
Trond Myklebust5d008372008-02-22 16:34:17 -0500834 if (task->tk_status != -ETIMEDOUT)
835 return;
Chuck Lever46121cf2007-01-31 12:14:08 -0500836 dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
Chuck Lever46c0ee82005-08-25 16:25:52 -0700837
Trond Myklebust5d008372008-02-22 16:34:17 -0500838 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400839 if (!req->rq_reply_bytes_recvd) {
Chuck Lever46c0ee82005-08-25 16:25:52 -0700840 if (xprt->ops->timer)
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500841 xprt->ops->timer(xprt, task);
Trond Myklebust5d008372008-02-22 16:34:17 -0500842 } else
843 task->tk_status = 0;
844 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845}
846
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300847static inline int xprt_has_timer(struct rpc_xprt *xprt)
848{
849 return xprt->idle_timeout != 0;
850}
851
Chuck Lever9903cd12005-08-11 16:25:26 -0400852/**
853 * xprt_prepare_transmit - reserve the transport before sending a request
854 * @task: RPC task about to send a request
855 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 */
Chuck Lever9903cd12005-08-11 16:25:26 -0400857int xprt_prepare_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858{
859 struct rpc_rqst *req = task->tk_rqstp;
860 struct rpc_xprt *xprt = req->rq_xprt;
861 int err = 0;
862
Chuck Lever46121cf2007-01-31 12:14:08 -0500863 dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400865 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400866 if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) {
867 err = req->rq_reply_bytes_recvd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 goto out_unlock;
869 }
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400870 if (!xprt->ops->reserve_xprt(xprt, task))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 err = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872out_unlock:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400873 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 return err;
875}
876
Trond Myklebuste0ab53d2006-07-27 17:22:50 -0400877void xprt_end_transmit(struct rpc_task *task)
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700878{
Rahul Iyer343952f2009-04-01 09:23:17 -0400879 xprt_release_write(task->tk_rqstp->rq_xprt, task);
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700880}
881
Chuck Lever9903cd12005-08-11 16:25:26 -0400882/**
883 * xprt_transmit - send an RPC request on a transport
884 * @task: controlling RPC task
885 *
886 * We have to copy the iovec because sendmsg fiddles with its contents.
887 */
888void xprt_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 struct rpc_rqst *req = task->tk_rqstp;
891 struct rpc_xprt *xprt = req->rq_xprt;
Andy Adamson15a45202012-02-14 16:19:18 -0500892 int status, numreqs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
Chuck Lever46121cf2007-01-31 12:14:08 -0500894 dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400896 if (!req->rq_reply_bytes_recvd) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400897 if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
898 /*
899 * Add to the list only if we're expecting a reply
900 */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400901 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 /* Update the softirq receive buffer */
903 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
904 sizeof(req->rq_private_buf));
905 /* Add request to the receive list */
906 list_add_tail(&req->rq_list, &xprt->recv);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400907 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 xprt_reset_majortimeo(req);
Trond Myklebust0f9dc2b2005-06-22 17:16:28 +0000909 /* Turn off autodisconnect */
910 del_singleshot_timer_sync(&xprt->timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 }
912 } else if (!req->rq_bytes_sent)
913 return;
914
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400915 req->rq_connect_cookie = xprt->connect_cookie;
Chuck Leverff839972010-05-07 13:34:47 -0400916 req->rq_xtime = ktime_get();
Chuck Levera246b012005-08-11 16:25:23 -0400917 status = xprt->ops->send_request(task);
Trond Myklebustc8485e42009-03-11 14:37:59 -0400918 if (status != 0) {
919 task->tk_status = status;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700920 return;
921 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922
Trond Myklebustc8485e42009-03-11 14:37:59 -0400923 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
Bryan Schumaker468f8612011-04-18 15:57:32 -0400924 task->tk_flags |= RPC_TASK_SENT;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400925 spin_lock_bh(&xprt->transport_lock);
926
927 xprt->ops->set_retrans_timeout(task);
928
Andy Adamson15a45202012-02-14 16:19:18 -0500929 numreqs = atomic_read(&xprt->num_reqs);
930 if (numreqs > xprt->stat.max_slots)
931 xprt->stat.max_slots = numreqs;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400932 xprt->stat.sends++;
933 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
934 xprt->stat.bklog_u += xprt->backlog.qlen;
Andy Adamson15a45202012-02-14 16:19:18 -0500935 xprt->stat.sending_u += xprt->sending.qlen;
936 xprt->stat.pending_u += xprt->pending.qlen;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400937
938 /* Don't race with disconnect */
939 if (!xprt_connected(xprt))
940 task->tk_status = -ENOTCONN;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400941 else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400942 /*
943 * Sleep on the pending queue since
944 * we're expecting a reply.
945 */
Trond Myklebustc8485e42009-03-11 14:37:59 -0400946 rpc_sleep_on(&xprt->pending, task, xprt_timer);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400947 }
Trond Myklebustc8485e42009-03-11 14:37:59 -0400948 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949}
950
Trond Myklebustba60eb22013-04-14 10:49:37 -0400951static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
952{
953 set_bit(XPRT_CONGESTED, &xprt->state);
954 rpc_sleep_on(&xprt->backlog, task, NULL);
955}
956
957static void xprt_wake_up_backlog(struct rpc_xprt *xprt)
958{
959 if (rpc_wake_up_next(&xprt->backlog) == NULL)
960 clear_bit(XPRT_CONGESTED, &xprt->state);
961}
962
963static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
964{
965 bool ret = false;
966
967 if (!test_bit(XPRT_CONGESTED, &xprt->state))
968 goto out;
969 spin_lock(&xprt->reserve_lock);
970 if (test_bit(XPRT_CONGESTED, &xprt->state)) {
971 rpc_sleep_on(&xprt->backlog, task, NULL);
972 ret = true;
973 }
974 spin_unlock(&xprt->reserve_lock);
975out:
976 return ret;
977}
978
Trond Myklebustd9ba1312011-07-17 18:11:30 -0400979static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
980{
981 struct rpc_rqst *req = ERR_PTR(-EAGAIN);
982
983 if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))
984 goto out;
985 req = kzalloc(sizeof(struct rpc_rqst), gfp_flags);
986 if (req != NULL)
987 goto out;
988 atomic_dec(&xprt->num_reqs);
989 req = ERR_PTR(-ENOMEM);
990out:
991 return req;
992}
993
994static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
995{
996 if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {
997 kfree(req);
998 return true;
999 }
1000 return false;
1001}
1002
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001003void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004{
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001005 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001007 spin_lock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 if (!list_empty(&xprt->free)) {
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001009 req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1010 list_del(&req->rq_list);
1011 goto out_init_req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 }
Jeff Layton6b343092012-05-16 13:30:35 -04001013 req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001014 if (!IS_ERR(req))
1015 goto out_init_req;
1016 switch (PTR_ERR(req)) {
1017 case -ENOMEM:
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001018 dprintk("RPC: dynamic allocation of request slot "
1019 "failed! Retrying\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001020 task->tk_status = -ENOMEM;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001021 break;
1022 case -EAGAIN:
Trond Myklebustba60eb22013-04-14 10:49:37 -04001023 xprt_add_backlog(xprt, task);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001024 dprintk("RPC: waiting for request slot\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001025 default:
1026 task->tk_status = -EAGAIN;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001027 }
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001028 spin_unlock(&xprt->reserve_lock);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001029 return;
1030out_init_req:
1031 task->tk_status = 0;
1032 task->tk_rqstp = req;
1033 xprt_request_init(task, xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001034 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035}
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001036EXPORT_SYMBOL_GPL(xprt_alloc_slot);
1037
1038void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
1039{
1040 /* Note: grabbing the xprt_lock_write() ensures that we throttle
1041 * new slot allocation if the transport is congested (i.e. when
1042 * reconnecting a stream transport or when out of socket write
1043 * buffer space).
1044 */
1045 if (xprt_lock_write(xprt, task)) {
1046 xprt_alloc_slot(xprt, task);
1047 xprt_release_write(xprt, task);
1048 }
1049}
1050EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001052static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1053{
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001054 spin_lock(&xprt->reserve_lock);
Trond Myklebustc25573b2011-12-01 14:16:17 -05001055 if (!xprt_dynamic_free_slot(xprt, req)) {
1056 memset(req, 0, sizeof(*req)); /* mark unused */
1057 list_add(&req->rq_list, &xprt->free);
1058 }
Trond Myklebustba60eb22013-04-14 10:49:37 -04001059 xprt_wake_up_backlog(xprt);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001060 spin_unlock(&xprt->reserve_lock);
1061}
1062
Trond Myklebust21de0a92011-07-17 16:57:32 -04001063static void xprt_free_all_slots(struct rpc_xprt *xprt)
1064{
1065 struct rpc_rqst *req;
1066 while (!list_empty(&xprt->free)) {
1067 req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list);
1068 list_del(&req->rq_list);
1069 kfree(req);
1070 }
1071}
1072
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001073struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
1074 unsigned int num_prealloc,
1075 unsigned int max_alloc)
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001076{
1077 struct rpc_xprt *xprt;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001078 struct rpc_rqst *req;
1079 int i;
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001080
1081 xprt = kzalloc(size, GFP_KERNEL);
1082 if (xprt == NULL)
1083 goto out;
1084
Trond Myklebust21de0a92011-07-17 16:57:32 -04001085 xprt_init(xprt, net);
1086
1087 for (i = 0; i < num_prealloc; i++) {
1088 req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
1089 if (!req)
1090 break;
1091 list_add(&req->rq_list, &xprt->free);
1092 }
1093 if (i < num_prealloc)
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001094 goto out_free;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001095 if (max_alloc > num_prealloc)
1096 xprt->max_reqs = max_alloc;
1097 else
1098 xprt->max_reqs = num_prealloc;
1099 xprt->min_reqs = num_prealloc;
1100 atomic_set(&xprt->num_reqs, num_prealloc);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001101
1102 return xprt;
1103
1104out_free:
Trond Myklebust21de0a92011-07-17 16:57:32 -04001105 xprt_free(xprt);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001106out:
1107 return NULL;
1108}
1109EXPORT_SYMBOL_GPL(xprt_alloc);
1110
Pavel Emelyanove204e622010-09-29 16:03:13 +04001111void xprt_free(struct rpc_xprt *xprt)
1112{
Pavel Emelyanov37aa2132010-09-29 16:05:43 +04001113 put_net(xprt->xprt_net);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001114 xprt_free_all_slots(xprt);
Pavel Emelyanove204e622010-09-29 16:03:13 +04001115 kfree(xprt);
1116}
1117EXPORT_SYMBOL_GPL(xprt_free);
1118
Chuck Lever9903cd12005-08-11 16:25:26 -04001119/**
1120 * xprt_reserve - allocate an RPC request slot
1121 * @task: RPC task requesting a slot allocation
1122 *
Trond Myklebustba60eb22013-04-14 10:49:37 -04001123 * If the transport is marked as being congested, or if no more
1124 * slots are available, place the task on the transport's
Chuck Lever9903cd12005-08-11 16:25:26 -04001125 * backlog queue.
1126 */
1127void xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128{
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001129 struct rpc_xprt *xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001131 task->tk_status = 0;
1132 if (task->tk_rqstp != NULL)
1133 return;
1134
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001135 task->tk_timeout = 0;
1136 task->tk_status = -EAGAIN;
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001137 rcu_read_lock();
1138 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustba60eb22013-04-14 10:49:37 -04001139 if (!xprt_throttle_congested(xprt, task))
1140 xprt->ops->alloc_slot(xprt, task);
1141 rcu_read_unlock();
1142}
1143
1144/**
1145 * xprt_retry_reserve - allocate an RPC request slot
1146 * @task: RPC task requesting a slot allocation
1147 *
1148 * If no more slots are available, place the task on the transport's
1149 * backlog queue.
1150 * Note that the only difference with xprt_reserve is that we now
1151 * ignore the value of the XPRT_CONGESTED flag.
1152 */
1153void xprt_retry_reserve(struct rpc_task *task)
1154{
1155 struct rpc_xprt *xprt;
1156
1157 task->tk_status = 0;
1158 if (task->tk_rqstp != NULL)
1159 return;
1160
1161 task->tk_timeout = 0;
1162 task->tk_status = -EAGAIN;
1163 rcu_read_lock();
1164 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001165 xprt->ops->alloc_slot(xprt, task);
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001166 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167}
1168
Alexey Dobriyand8ed0292006-09-26 22:29:38 -07001169static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170{
Eric Dumazet0eae88f2010-04-20 19:06:52 -07001171 return (__force __be32)xprt->xid++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172}
1173
1174static inline void xprt_init_xid(struct rpc_xprt *xprt)
1175{
Chuck Leverbf3fcf82006-05-25 01:40:51 -04001176 xprt->xid = net_random();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177}
1178
Chuck Lever9903cd12005-08-11 16:25:26 -04001179static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180{
1181 struct rpc_rqst *req = task->tk_rqstp;
1182
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001183 INIT_LIST_HEAD(&req->rq_list);
Trond Myklebustba7392b2007-12-20 16:03:55 -05001184 req->rq_timeout = task->tk_client->cl_timeout->to_initval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 req->rq_task = task;
1186 req->rq_xprt = xprt;
Chuck Lever02107142006-01-03 09:55:49 +01001187 req->rq_buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 req->rq_xid = xprt_alloc_xid(xprt);
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001189 req->rq_release_snd_buf = NULL;
Trond Myklebustda458282006-08-31 15:44:52 -04001190 xprt_reset_majortimeo(req);
Chuck Lever46121cf2007-01-31 12:14:08 -05001191 dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 req, ntohl(req->rq_xid));
1193}
1194
Chuck Lever9903cd12005-08-11 16:25:26 -04001195/**
1196 * xprt_release - release an RPC request slot
1197 * @task: task which is finished with the slot
1198 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 */
Chuck Lever9903cd12005-08-11 16:25:26 -04001200void xprt_release(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201{
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001202 struct rpc_xprt *xprt;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001203 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204
Trond Myklebust87ed5002013-01-07 14:30:46 -05001205 if (req == NULL) {
1206 if (task->tk_client) {
1207 rcu_read_lock();
1208 xprt = rcu_dereference(task->tk_client->cl_xprt);
1209 if (xprt->snd_task == task)
1210 xprt_release_write(xprt, task);
1211 rcu_read_unlock();
1212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 return;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001214 }
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001215
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001216 xprt = req->rq_xprt;
Weston Andros Adamson0a702192012-02-17 13:15:24 -05001217 if (task->tk_ops->rpc_count_stats != NULL)
1218 task->tk_ops->rpc_count_stats(task, task->tk_calldata);
1219 else if (task->tk_client)
1220 rpc_count_iostats(task, task->tk_client->cl_metrics);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001221 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -07001222 xprt->ops->release_xprt(xprt, task);
Chuck Levera58dd392005-08-25 16:25:53 -07001223 if (xprt->ops->release_request)
1224 xprt->ops->release_request(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 if (!list_empty(&req->rq_list))
1226 list_del(&req->rq_list);
1227 xprt->last_used = jiffies;
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001228 if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
Chuck Levera246b012005-08-11 16:25:23 -04001229 mod_timer(&xprt->timer,
Chuck Lever03bf4b72005-08-25 16:25:55 -07001230 xprt->last_used + xprt->idle_timeout);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001231 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001232 if (req->rq_buffer)
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001233 xprt->ops->buf_free(req->rq_buffer);
Trond Myklebusta17c2152010-07-31 14:29:08 -04001234 if (req->rq_cred != NULL)
1235 put_rpccred(req->rq_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 task->tk_rqstp = NULL;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001237 if (req->rq_release_snd_buf)
1238 req->rq_release_snd_buf(req);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001239
Chuck Lever46121cf2007-01-31 12:14:08 -05001240 dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001241 if (likely(!bc_prealloc(req)))
1242 xprt_free_slot(xprt, req);
1243 else
Trond Myklebustc9acb422010-03-19 15:36:22 -04001244 xprt_free_bc_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245}
1246
Trond Myklebust21de0a92011-07-17 16:57:32 -04001247static void xprt_init(struct rpc_xprt *xprt, struct net *net)
Chuck Leverc2866762006-08-22 20:06:20 -04001248{
Trond Myklebust21de0a92011-07-17 16:57:32 -04001249 atomic_set(&xprt->count, 1);
Chuck Leverc2866762006-08-22 20:06:20 -04001250
1251 spin_lock_init(&xprt->transport_lock);
1252 spin_lock_init(&xprt->reserve_lock);
1253
1254 INIT_LIST_HEAD(&xprt->free);
1255 INIT_LIST_HEAD(&xprt->recv);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001256#if defined(CONFIG_SUNRPC_BACKCHANNEL)
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001257 spin_lock_init(&xprt->bc_pa_lock);
1258 INIT_LIST_HEAD(&xprt->bc_pa_list);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001259#endif /* CONFIG_SUNRPC_BACKCHANNEL */
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001260
Chuck Leverc2866762006-08-22 20:06:20 -04001261 xprt->last_used = jiffies;
1262 xprt->cwnd = RPC_INITCWND;
Chuck Levera5090502007-03-29 16:48:04 -04001263 xprt->bind_index = 0;
Chuck Leverc2866762006-08-22 20:06:20 -04001264
1265 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
1266 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
Trond Myklebust34006ce2011-07-17 18:11:34 -04001267 rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending");
Chuck Leverc2866762006-08-22 20:06:20 -04001268 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1269
Chuck Leverc2866762006-08-22 20:06:20 -04001270 xprt_init_xid(xprt);
1271
Trond Myklebust21de0a92011-07-17 16:57:32 -04001272 xprt->xprt_net = get_net(net);
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001273}
1274
1275/**
1276 * xprt_create_transport - create an RPC transport
1277 * @args: rpc transport creation arguments
1278 *
1279 */
1280struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
1281{
1282 struct rpc_xprt *xprt;
1283 struct xprt_class *t;
1284
1285 spin_lock(&xprt_list_lock);
1286 list_for_each_entry(t, &xprt_list, list) {
1287 if (t->ident == args->ident) {
1288 spin_unlock(&xprt_list_lock);
1289 goto found;
1290 }
1291 }
1292 spin_unlock(&xprt_list_lock);
1293 printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
1294 return ERR_PTR(-EIO);
1295
1296found:
1297 xprt = t->setup(args);
1298 if (IS_ERR(xprt)) {
1299 dprintk("RPC: xprt_create_transport: failed, %ld\n",
1300 -PTR_ERR(xprt));
Trond Myklebust21de0a92011-07-17 16:57:32 -04001301 goto out;
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001302 }
J. Bruce Fields33d90ac2013-04-11 15:06:36 -04001303 if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
1304 xprt->idle_timeout = 0;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001305 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
1306 if (xprt_has_timer(xprt))
1307 setup_timer(&xprt->timer, xprt_init_autodisconnect,
1308 (unsigned long)xprt);
1309 else
1310 init_timer(&xprt->timer);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001311
1312 if (strlen(args->servername) > RPC_MAXNETNAMELEN) {
1313 xprt_destroy(xprt);
1314 return ERR_PTR(-EINVAL);
1315 }
1316 xprt->servername = kstrdup(args->servername, GFP_KERNEL);
1317 if (xprt->servername == NULL) {
1318 xprt_destroy(xprt);
1319 return ERR_PTR(-ENOMEM);
1320 }
1321
Chuck Lever46121cf2007-01-31 12:14:08 -05001322 dprintk("RPC: created transport %p with %u slots\n", xprt,
Chuck Leverc2866762006-08-22 20:06:20 -04001323 xprt->max_reqs);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001324out:
Chuck Leverc2866762006-08-22 20:06:20 -04001325 return xprt;
1326}
1327
Chuck Lever9903cd12005-08-11 16:25:26 -04001328/**
1329 * xprt_destroy - destroy an RPC transport, killing off all requests.
Trond Myklebusta8de2402011-03-15 19:56:30 -04001330 * @xprt: transport to destroy
Chuck Lever9903cd12005-08-11 16:25:26 -04001331 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 */
Trond Myklebusta8de2402011-03-15 19:56:30 -04001333static void xprt_destroy(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334{
Chuck Lever46121cf2007-01-31 12:14:08 -05001335 dprintk("RPC: destroying transport %p\n", xprt);
Trond Myklebust0065db32006-01-03 09:55:56 +01001336 del_timer_sync(&xprt->timer);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001337
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001338 rpc_destroy_wait_queue(&xprt->binding);
1339 rpc_destroy_wait_queue(&xprt->pending);
1340 rpc_destroy_wait_queue(&xprt->sending);
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001341 rpc_destroy_wait_queue(&xprt->backlog);
J. Bruce Fieldsc3ae62ae2010-08-03 17:22:20 -04001342 cancel_work_sync(&xprt->task_cleanup);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001343 kfree(xprt->servername);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001344 /*
1345 * Tear down transport state and free the rpc_xprt
1346 */
Chuck Levera246b012005-08-11 16:25:23 -04001347 xprt->ops->destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001348}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001350/**
1351 * xprt_put - release a reference to an RPC transport.
1352 * @xprt: pointer to the transport
1353 *
1354 */
1355void xprt_put(struct rpc_xprt *xprt)
1356{
Trond Myklebusta8de2402011-03-15 19:56:30 -04001357 if (atomic_dec_and_test(&xprt->count))
1358 xprt_destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001359}
1360
1361/**
1362 * xprt_get - return a reference to an RPC transport.
1363 * @xprt: pointer to the transport
1364 *
1365 */
1366struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
1367{
Trond Myklebusta8de2402011-03-15 19:56:30 -04001368 if (atomic_inc_not_zero(&xprt->count))
1369 return xprt;
1370 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371}