blob: 37edea6fa92d9685570ad3c1b37cb5fda5c0b9b3 [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
Jeff Layton3705ad62014-10-28 14:24:13 -040052#include <trace/events/sunrpc.h>
53
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -040054#include "sunrpc.h"
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056/*
57 * Local variables
58 */
59
Jeff Laytonf895b252014-11-17 16:58:04 -050060#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
Linus Torvalds1da177e2005-04-16 15:20:36 -070061# define RPCDBG_FACILITY RPCDBG_XPRT
62#endif
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064/*
65 * Local functions
66 */
Trond Myklebust21de0a92011-07-17 16:57:32 -040067static void xprt_init(struct rpc_xprt *xprt, struct net *net);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static void xprt_connect_status(struct rpc_task *task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
Neil Brown29807312015-06-15 15:55:30 +100071static void __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *);
Trond Myklebust4e0038b2012-03-01 17:01:05 -050072static void xprt_destroy(struct rpc_xprt *xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Jiri Slaby5ba03e82007-11-22 19:40:22 +080074static DEFINE_SPINLOCK(xprt_list_lock);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040075static LIST_HEAD(xprt_list);
76
Chuck Lever12a80462005-08-25 16:25:51 -070077/**
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040078 * xprt_register_transport - register a transport implementation
79 * @transport: transport to register
80 *
81 * If a transport implementation is loaded as a kernel module, it can
82 * call this interface to make itself known to the RPC client.
83 *
84 * Returns:
85 * 0: transport successfully registered
86 * -EEXIST: transport already registered
87 * -EINVAL: transport module being unloaded
88 */
89int xprt_register_transport(struct xprt_class *transport)
90{
91 struct xprt_class *t;
92 int result;
93
94 result = -EEXIST;
95 spin_lock(&xprt_list_lock);
96 list_for_each_entry(t, &xprt_list, list) {
97 /* don't register the same transport class twice */
\"Talpey, Thomas\4fa016e2007-09-10 13:47:57 -040098 if (t->ident == transport->ident)
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -040099 goto out;
100 }
101
Denis V. Lunevc9f6cde2008-07-31 09:53:56 +0400102 list_add_tail(&transport->list, &xprt_list);
103 printk(KERN_INFO "RPC: Registered %s transport module.\n",
104 transport->name);
105 result = 0;
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400106
107out:
108 spin_unlock(&xprt_list_lock);
109 return result;
110}
111EXPORT_SYMBOL_GPL(xprt_register_transport);
112
113/**
114 * xprt_unregister_transport - unregister a transport implementation
Randy Dunlap65b6e422008-02-13 15:03:23 -0800115 * @transport: transport to unregister
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400116 *
117 * Returns:
118 * 0: transport successfully unregistered
119 * -ENOENT: transport never registered
120 */
121int xprt_unregister_transport(struct xprt_class *transport)
122{
123 struct xprt_class *t;
124 int result;
125
126 result = 0;
127 spin_lock(&xprt_list_lock);
128 list_for_each_entry(t, &xprt_list, list) {
129 if (t == transport) {
130 printk(KERN_INFO
131 "RPC: Unregistered %s transport module.\n",
132 transport->name);
133 list_del_init(&transport->list);
\"Talpey, Thomas\81c098a2007-09-10 13:46:00 -0400134 goto out;
135 }
136 }
137 result = -ENOENT;
138
139out:
140 spin_unlock(&xprt_list_lock);
141 return result;
142}
143EXPORT_SYMBOL_GPL(xprt_unregister_transport);
144
145/**
Tom Talpey441e3e22009-03-11 14:37:56 -0400146 * xprt_load_transport - load a transport implementation
147 * @transport_name: transport to load
148 *
149 * Returns:
150 * 0: transport successfully loaded
151 * -ENOENT: transport module not available
152 */
153int xprt_load_transport(const char *transport_name)
154{
155 struct xprt_class *t;
Tom Talpey441e3e22009-03-11 14:37:56 -0400156 int result;
157
158 result = 0;
159 spin_lock(&xprt_list_lock);
160 list_for_each_entry(t, &xprt_list, list) {
161 if (strcmp(t->name, transport_name) == 0) {
162 spin_unlock(&xprt_list_lock);
163 goto out;
164 }
165 }
166 spin_unlock(&xprt_list_lock);
Alex Riesenef7ffe82010-05-24 14:33:05 -0700167 result = request_module("xprt%s", transport_name);
Tom Talpey441e3e22009-03-11 14:37:56 -0400168out:
169 return result;
170}
171EXPORT_SYMBOL_GPL(xprt_load_transport);
172
173/**
Chuck Lever12a80462005-08-25 16:25:51 -0700174 * xprt_reserve_xprt - serialize write access to transports
175 * @task: task that is requesting access to the transport
Randy Dunlap177c27b2011-07-28 06:54:36 +0000176 * @xprt: pointer to the target transport
Chuck Lever12a80462005-08-25 16:25:51 -0700177 *
178 * This prevents mixing the payload of separate requests, and prevents
179 * transport connects from colliding with writes. No congestion control
180 * is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400182int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
Chuck Lever12a80462005-08-25 16:25:51 -0700184 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400185 int priority;
Chuck Lever12a80462005-08-25 16:25:51 -0700186
187 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
188 if (task == xprt->snd_task)
189 return 1;
Chuck Lever12a80462005-08-25 16:25:51 -0700190 goto out_sleep;
191 }
192 xprt->snd_task = task;
Trond Myklebust92551942013-09-27 11:28:40 -0400193 if (req != NULL)
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400194 req->rq_ntrans++;
j223yang@asset.uwaterloo.ca4d4a76f2011-03-10 12:40:28 -0500195
Chuck Lever12a80462005-08-25 16:25:51 -0700196 return 1;
197
198out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500199 dprintk("RPC: %5u failed to lock transport %p\n",
Chuck Lever12a80462005-08-25 16:25:51 -0700200 task->tk_pid, xprt);
201 task->tk_timeout = 0;
202 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400203 if (req == NULL)
204 priority = RPC_PRIORITY_LOW;
205 else if (!req->rq_ntrans)
206 priority = RPC_PRIORITY_NORMAL;
Chuck Lever12a80462005-08-25 16:25:51 -0700207 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400208 priority = RPC_PRIORITY_HIGH;
209 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Chuck Lever12a80462005-08-25 16:25:51 -0700210 return 0;
211}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400212EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
Chuck Lever12a80462005-08-25 16:25:51 -0700213
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100214static void xprt_clear_locked(struct rpc_xprt *xprt)
215{
216 xprt->snd_task = NULL;
Trond Myklebustd19751e2012-09-11 17:21:25 -0400217 if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
Peter Zijlstra4e857c52014-03-17 18:06:10 +0100218 smp_mb__before_atomic();
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100219 clear_bit(XPRT_LOCKED, &xprt->state);
Peter Zijlstra4e857c52014-03-17 18:06:10 +0100220 smp_mb__after_atomic();
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100221 } else
Trond Myklebustc1384c92007-06-14 18:00:42 -0400222 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100223}
224
Chuck Lever12a80462005-08-25 16:25:51 -0700225/*
226 * xprt_reserve_xprt_cong - serialize write access to transports
227 * @task: task that is requesting access to the transport
228 *
229 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
230 * integrated into the decision of whether a request is allowed to be
231 * woken up and given access to the transport.
232 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400233int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
Chuck Lever12a80462005-08-25 16:25:51 -0700234{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400236 int priority;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
Chuck Lever2226feb2005-08-11 16:25:38 -0400238 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 if (task == xprt->snd_task)
240 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 goto out_sleep;
242 }
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400243 if (req == NULL) {
244 xprt->snd_task = task;
245 return 1;
246 }
Chuck Lever12a80462005-08-25 16:25:51 -0700247 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400249 req->rq_ntrans++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 return 1;
251 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100252 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253out_sleep:
Neil Brown29807312015-06-15 15:55:30 +1000254 if (req)
255 __xprt_put_cong(xprt, req);
Chuck Lever46121cf2007-01-31 12:14:08 -0500256 dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 task->tk_timeout = 0;
258 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400259 if (req == NULL)
260 priority = RPC_PRIORITY_LOW;
261 else if (!req->rq_ntrans)
262 priority = RPC_PRIORITY_NORMAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400264 priority = RPC_PRIORITY_HIGH;
265 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 return 0;
267}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400268EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Chuck Lever12a80462005-08-25 16:25:51 -0700270static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
272 int retval;
273
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400274 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400275 retval = xprt->ops->reserve_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400276 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 return retval;
278}
279
Trond Myklebust961a8282012-01-17 22:57:37 -0500280static bool __xprt_lock_write_func(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281{
Trond Myklebust961a8282012-01-17 22:57:37 -0500282 struct rpc_xprt *xprt = data;
Chuck Lever49e9a892005-08-25 16:25:51 -0700283 struct rpc_rqst *req;
284
Chuck Lever49e9a892005-08-25 16:25:51 -0700285 req = task->tk_rqstp;
286 xprt->snd_task = task;
Trond Myklebust92551942013-09-27 11:28:40 -0400287 if (req)
Chuck Lever49e9a892005-08-25 16:25:51 -0700288 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500289 return true;
290}
Chuck Lever49e9a892005-08-25 16:25:51 -0700291
Trond Myklebust961a8282012-01-17 22:57:37 -0500292static void __xprt_lock_write_next(struct rpc_xprt *xprt)
293{
294 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
295 return;
296
297 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt))
298 return;
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100299 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700300}
301
Trond Myklebust961a8282012-01-17 22:57:37 -0500302static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data)
Chuck Lever49e9a892005-08-25 16:25:51 -0700303{
Trond Myklebust961a8282012-01-17 22:57:37 -0500304 struct rpc_xprt *xprt = data;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400305 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400307 req = task->tk_rqstp;
308 if (req == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 xprt->snd_task = task;
Trond Myklebust961a8282012-01-17 22:57:37 -0500310 return true;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400311 }
312 if (__xprt_get_cong(xprt, task)) {
313 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400314 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500315 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 }
Trond Myklebust961a8282012-01-17 22:57:37 -0500317 return false;
318}
319
320static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
321{
322 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
323 return;
324 if (RPCXPRT_CONGESTED(xprt))
325 goto out_unlock;
326 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt))
327 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100329 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330}
331
Trond Myklebust06953142015-03-23 16:10:00 -0400332static void xprt_task_clear_bytes_sent(struct rpc_task *task)
333{
334 if (task != NULL) {
335 struct rpc_rqst *req = task->tk_rqstp;
336 if (req != NULL)
337 req->rq_bytes_sent = 0;
338 }
339}
340
Chuck Lever49e9a892005-08-25 16:25:51 -0700341/**
342 * xprt_release_xprt - allow other requests to use a transport
343 * @xprt: transport with other tasks potentially waiting
344 * @task: task that is releasing access to the transport
345 *
346 * Note that "task" can be NULL. No congestion control is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 */
Chuck Lever49e9a892005-08-25 16:25:51 -0700348void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349{
350 if (xprt->snd_task == task) {
Trond Myklebust06953142015-03-23 16:10:00 -0400351 xprt_task_clear_bytes_sent(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 Myklebust06953142015-03-23 16:10:00 -0400369 xprt_task_clear_bytes_sent(task);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100370 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700371 __xprt_lock_write_next_cong(xprt);
372 }
373}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400374EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
Chuck Lever49e9a892005-08-25 16:25:51 -0700375
376static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400378 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -0700379 xprt->ops->release_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400380 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381}
382
383/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 * Van Jacobson congestion avoidance. Check if the congestion window
385 * overflowed. Put the task to sleep if this is the case.
386 */
387static int
388__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
389{
390 struct rpc_rqst *req = task->tk_rqstp;
391
392 if (req->rq_cong)
393 return 1;
Chuck Lever46121cf2007-01-31 12:14:08 -0500394 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 task->tk_pid, xprt->cong, xprt->cwnd);
396 if (RPCXPRT_CONGESTED(xprt))
397 return 0;
398 req->rq_cong = 1;
399 xprt->cong += RPC_CWNDSCALE;
400 return 1;
401}
402
403/*
404 * Adjust the congestion window, and wake up the next task
405 * that has been sleeping due to congestion
406 */
407static void
408__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
409{
410 if (!req->rq_cong)
411 return;
412 req->rq_cong = 0;
413 xprt->cong -= RPC_CWNDSCALE;
Chuck Lever49e9a892005-08-25 16:25:51 -0700414 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
416
Chuck Lever46c0ee82005-08-25 16:25:52 -0700417/**
Chuck Levera58dd392005-08-25 16:25:53 -0700418 * xprt_release_rqst_cong - housekeeping when request is complete
419 * @task: RPC request that recently completed
420 *
421 * Useful for transports that require congestion control.
422 */
423void xprt_release_rqst_cong(struct rpc_task *task)
424{
Trond Myklebusta4f08352013-01-08 09:10:21 -0500425 struct rpc_rqst *req = task->tk_rqstp;
426
427 __xprt_put_cong(req->rq_xprt, req);
Chuck Levera58dd392005-08-25 16:25:53 -0700428}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400429EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
Chuck Levera58dd392005-08-25 16:25:53 -0700430
431/**
Chuck Lever46c0ee82005-08-25 16:25:52 -0700432 * xprt_adjust_cwnd - adjust transport congestion window
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500433 * @xprt: pointer to xprt
Chuck Lever46c0ee82005-08-25 16:25:52 -0700434 * @task: recently completed RPC request used to adjust window
435 * @result: result code of completed RPC request
436 *
Chuck Lever4f4cf5a2014-05-28 10:34:49 -0400437 * The transport code maintains an estimate on the maximum number of out-
438 * standing RPC requests, using a smoothed version of the congestion
439 * avoidance implemented in 44BSD. This is basically the Van Jacobson
440 * congestion algorithm: If a retransmit occurs, the congestion window is
441 * halved; otherwise, it is incremented by 1/cwnd when
442 *
443 * - a reply is received and
444 * - a full number of requests are outstanding and
445 * - the congestion window hasn't been updated recently.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 */
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
Trond Myklebust66af1e52007-11-06 10:18:36 -0500614 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
Trond Myklebust4876cc72015-06-19 16:17:57 -0400615 xprt->ops->close(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 xprt_release_write(xprt, NULL);
Trond Myklebust79234c32015-09-18 15:53:24 -0400617 wake_up_bit(&xprt->state, XPRT_LOCKED);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618}
619
Chuck Lever9903cd12005-08-11 16:25:26 -0400620/**
Trond Myklebust62da3b22007-11-06 18:44:20 -0500621 * xprt_disconnect_done - mark a transport as disconnected
Chuck Lever9903cd12005-08-11 16:25:26 -0400622 * @xprt: transport to flag for disconnect
623 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 */
Trond Myklebust62da3b22007-11-06 18:44:20 -0500625void xprt_disconnect_done(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626{
Chuck Lever46121cf2007-01-31 12:14:08 -0500627 dprintk("RPC: disconnected transport %p\n", xprt);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400628 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 xprt_clear_connected(xprt);
Trond Myklebust2a491992009-03-11 14:38:00 -0400630 xprt_wake_pending_tasks(xprt, -EAGAIN);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400631 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632}
Trond Myklebust62da3b22007-11-06 18:44:20 -0500633EXPORT_SYMBOL_GPL(xprt_disconnect_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Trond Myklebust66af1e52007-11-06 10:18:36 -0500635/**
636 * xprt_force_disconnect - force a transport to disconnect
637 * @xprt: transport to disconnect
638 *
639 */
640void xprt_force_disconnect(struct rpc_xprt *xprt)
641{
642 /* Don't race with the test_bit() in xprt_clear_locked() */
643 spin_lock_bh(&xprt->transport_lock);
644 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
645 /* Try to schedule an autoclose RPC call */
646 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
647 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400648 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500649 spin_unlock_bh(&xprt->transport_lock);
650}
Trond Myklebust66af1e52007-11-06 10:18:36 -0500651
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400652/**
653 * xprt_conditional_disconnect - force a transport to disconnect
654 * @xprt: transport to disconnect
655 * @cookie: 'connection cookie'
656 *
657 * This attempts to break the connection if and only if 'cookie' matches
658 * the current transport 'connection cookie'. It ensures that we don't
659 * try to break the connection more than once when we need to retransmit
660 * a batch of RPC requests.
661 *
662 */
663void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
664{
665 /* Don't race with the test_bit() in xprt_clear_locked() */
666 spin_lock_bh(&xprt->transport_lock);
667 if (cookie != xprt->connect_cookie)
668 goto out;
669 if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
670 goto out;
671 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
672 /* Try to schedule an autoclose RPC call */
673 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
674 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400675 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400676out:
677 spin_unlock_bh(&xprt->transport_lock);
678}
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680static void
681xprt_init_autodisconnect(unsigned long data)
682{
683 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
684
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400685 spin_lock(&xprt->transport_lock);
Trond Myklebustd19751e2012-09-11 17:21:25 -0400686 if (!list_empty(&xprt->recv))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 goto out_abort;
Chuck Lever2226feb2005-08-11 16:25:38 -0400688 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 goto out_abort;
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400690 spin_unlock(&xprt->transport_lock);
Trond Myklebustf75e6742009-04-21 17:18:20 -0400691 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
Trond Myklebust718ba5b2015-02-08 18:19:25 -0500697bool xprt_lock_connect(struct rpc_xprt *xprt,
698 struct rpc_task *task,
699 void *cookie)
700{
701 bool ret = false;
702
703 spin_lock_bh(&xprt->transport_lock);
704 if (!test_bit(XPRT_LOCKED, &xprt->state))
705 goto out;
706 if (xprt->snd_task != task)
707 goto out;
Trond Myklebust06953142015-03-23 16:10:00 -0400708 xprt_task_clear_bytes_sent(task);
Trond Myklebust718ba5b2015-02-08 18:19:25 -0500709 xprt->snd_task = cookie;
710 ret = true;
711out:
712 spin_unlock_bh(&xprt->transport_lock);
713 return ret;
714}
715
716void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie)
717{
718 spin_lock_bh(&xprt->transport_lock);
719 if (xprt->snd_task != cookie)
720 goto out;
721 if (!test_bit(XPRT_LOCKED, &xprt->state))
722 goto out;
723 xprt->snd_task =NULL;
724 xprt->ops->release_xprt(xprt, NULL);
725out:
726 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebust79234c32015-09-18 15:53:24 -0400727 wake_up_bit(&xprt->state, XPRT_LOCKED);
Trond Myklebust718ba5b2015-02-08 18:19:25 -0500728}
729
Chuck Lever9903cd12005-08-11 16:25:26 -0400730/**
731 * xprt_connect - schedule a transport connect operation
732 * @task: RPC task that is requesting the connect
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 *
734 */
735void xprt_connect(struct rpc_task *task)
736{
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 Lever46121cf2007-01-31 12:14:08 -0500739 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 xprt, (xprt_connected(xprt) ? "is" : "is not"));
741
Chuck Leverec739ef2006-08-22 20:06:15 -0400742 if (!xprt_bound(xprt)) {
Trond Myklebust01d37c42009-03-11 14:09:39 -0400743 task->tk_status = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 return;
745 }
746 if (!xprt_lock_write(xprt, task))
747 return;
Trond Myklebustfeb8ca32009-12-03 08:10:17 -0500748
749 if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
750 xprt->ops->close(xprt);
751
Trond Myklebust718ba5b2015-02-08 18:19:25 -0500752 if (!xprt_connected(xprt)) {
Dan Carpenter87e3c052012-02-01 10:46:20 +0300753 task->tk_rqstp->rq_bytes_sent = 0;
Trond Myklebusta8ce4a82010-04-16 16:42:12 -0400754 task->tk_timeout = task->tk_rqstp->rq_timeout;
Trond Myklebust5d008372008-02-22 16:34:17 -0500755 rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
Trond Myklebust0b9e7942010-04-16 16:41:57 -0400756
757 if (test_bit(XPRT_CLOSING, &xprt->state))
758 return;
759 if (xprt_test_and_set_connecting(xprt))
760 return;
Chuck Lever262ca072006-03-20 13:44:16 -0500761 xprt->stat.connect_start = jiffies;
Trond Myklebust1b092092013-01-08 09:26:49 -0500762 xprt->ops->connect(xprt, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 }
Trond Myklebust718ba5b2015-02-08 18:19:25 -0500764 xprt_release_write(xprt, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765}
766
Chuck Lever9903cd12005-08-11 16:25:26 -0400767static void xprt_connect_status(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500769 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770
Chuck Levercd983ef2008-06-11 17:56:13 -0400771 if (task->tk_status == 0) {
Chuck Lever262ca072006-03-20 13:44:16 -0500772 xprt->stat.connect_count++;
773 xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
Chuck Lever46121cf2007-01-31 12:14:08 -0500774 dprintk("RPC: %5u xprt_connect_status: connection established\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 task->tk_pid);
776 return;
777 }
778
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 switch (task->tk_status) {
Trond Myklebust0fe8d042013-12-31 13:13:30 -0500780 case -ECONNREFUSED:
781 case -ECONNRESET:
782 case -ECONNABORTED:
783 case -ENETUNREACH:
784 case -EHOSTUNREACH:
Trond Myklebust2fc193c2014-07-03 00:02:57 -0400785 case -EPIPE:
Trond Myklebust2a491992009-03-11 14:38:00 -0400786 case -EAGAIN:
787 dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
Chuck Lever23475d62005-08-11 16:25:08 -0400788 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 case -ETIMEDOUT:
Chuck Lever46121cf2007-01-31 12:14:08 -0500790 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
791 "out\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 break;
793 default:
Chuck Lever46121cf2007-01-31 12:14:08 -0500794 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
795 "server %s\n", task->tk_pid, -task->tk_status,
Trond Myklebust4e0038b2012-03-01 17:01:05 -0500796 xprt->servername);
Chuck Lever23475d62005-08-11 16:25:08 -0400797 task->tk_status = -EIO;
Chuck Lever23475d62005-08-11 16:25:08 -0400798 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799}
800
Chuck Lever9903cd12005-08-11 16:25:26 -0400801/**
802 * xprt_lookup_rqst - find an RPC request corresponding to an XID
803 * @xprt: transport on which the original request was transmitted
804 * @xid: RPC XID of incoming reply
805 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700807struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808{
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400809 struct rpc_rqst *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400811 list_for_each_entry(entry, &xprt->recv, rq_list)
Jeff Layton3705ad62014-10-28 14:24:13 -0400812 if (entry->rq_xid == xid) {
813 trace_xprt_lookup_rqst(xprt, xid, 0);
Chuck Lever262ca072006-03-20 13:44:16 -0500814 return entry;
Jeff Layton3705ad62014-10-28 14:24:13 -0400815 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500816
817 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
818 ntohl(xid));
Jeff Layton3705ad62014-10-28 14:24:13 -0400819 trace_xprt_lookup_rqst(xprt, xid, -ENOENT);
Chuck Lever262ca072006-03-20 13:44:16 -0500820 xprt->stat.bad_xids++;
821 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400823EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400825static void xprt_update_rtt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826{
Chuck Lever1570c1e2005-08-25 16:25:52 -0700827 struct rpc_rqst *req = task->tk_rqstp;
828 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
Eric Dumazet95c96172012-04-15 05:58:06 +0000829 unsigned int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400830 long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
Chuck Lever1570c1e2005-08-25 16:25:52 -0700832 if (timer) {
833 if (req->rq_ntrans == 1)
Chuck Leverff839972010-05-07 13:34:47 -0400834 rpc_update_rtt(rtt, timer, m);
Chuck Lever1570c1e2005-08-25 16:25:52 -0700835 rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 }
Chuck Lever1570c1e2005-08-25 16:25:52 -0700837}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838
Chuck Lever1570c1e2005-08-25 16:25:52 -0700839/**
840 * xprt_complete_rqst - called when reply processing is complete
841 * @task: RPC request that recently completed
842 * @copied: actual number of bytes received from the transport
843 *
844 * Caller holds transport lock.
845 */
846void xprt_complete_rqst(struct rpc_task *task, int copied)
847{
848 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustfda13932008-02-22 16:34:12 -0500849 struct rpc_xprt *xprt = req->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
Chuck Lever1570c1e2005-08-25 16:25:52 -0700851 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
852 task->tk_pid, ntohl(req->rq_xid), copied);
Jeff Layton3705ad62014-10-28 14:24:13 -0400853 trace_xprt_complete_rqst(xprt, req->rq_xid, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
Trond Myklebustfda13932008-02-22 16:34:12 -0500855 xprt->stat.recvs++;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400856 req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime);
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400857 if (xprt->ops->timer != NULL)
858 xprt_update_rtt(task);
Chuck Leveref759a22006-03-20 13:44:17 -0500859
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 list_del_init(&req->rq_list);
Trond Myklebust1e799b62008-03-21 16:19:41 -0400861 req->rq_private_buf.len = copied;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400862 /* Ensure all writes are done before we update */
863 /* req->rq_reply_bytes_recvd */
Trond Myklebust43ac3f22006-03-20 13:44:51 -0500864 smp_wmb();
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400865 req->rq_reply_bytes_recvd = copied;
Trond Myklebustfda13932008-02-22 16:34:12 -0500866 rpc_wake_up_queued_task(&xprt->pending, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400868EXPORT_SYMBOL_GPL(xprt_complete_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
Chuck Lever46c0ee82005-08-25 16:25:52 -0700870static void xprt_timer(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700872 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 struct rpc_xprt *xprt = req->rq_xprt;
874
Trond Myklebust5d008372008-02-22 16:34:17 -0500875 if (task->tk_status != -ETIMEDOUT)
876 return;
Chuck Lever46121cf2007-01-31 12:14:08 -0500877 dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
Chuck Lever46c0ee82005-08-25 16:25:52 -0700878
Trond Myklebust5d008372008-02-22 16:34:17 -0500879 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400880 if (!req->rq_reply_bytes_recvd) {
Chuck Lever46c0ee82005-08-25 16:25:52 -0700881 if (xprt->ops->timer)
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500882 xprt->ops->timer(xprt, task);
Trond Myklebust5d008372008-02-22 16:34:17 -0500883 } else
884 task->tk_status = 0;
885 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886}
887
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300888static inline int xprt_has_timer(struct rpc_xprt *xprt)
889{
890 return xprt->idle_timeout != 0;
891}
892
Chuck Lever9903cd12005-08-11 16:25:26 -0400893/**
894 * xprt_prepare_transmit - reserve the transport before sending a request
895 * @task: RPC task about to send a request
896 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 */
Trond Myklebust90051ea2013-09-25 12:17:18 -0400898bool xprt_prepare_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899{
900 struct rpc_rqst *req = task->tk_rqstp;
901 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebust90051ea2013-09-25 12:17:18 -0400902 bool ret = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Chuck Lever46121cf2007-01-31 12:14:08 -0500904 dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400906 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust8a19a0b2013-09-24 12:00:27 -0400907 if (!req->rq_bytes_sent) {
908 if (req->rq_reply_bytes_recvd) {
909 task->tk_status = req->rq_reply_bytes_recvd;
910 goto out_unlock;
911 }
912 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
913 && xprt_connected(xprt)
914 && req->rq_connect_cookie == xprt->connect_cookie) {
915 xprt->ops->set_retrans_timeout(task);
916 rpc_sleep_on(&xprt->pending, task, xprt_timer);
917 goto out_unlock;
918 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 }
Trond Myklebust90051ea2013-09-25 12:17:18 -0400920 if (!xprt->ops->reserve_xprt(xprt, task)) {
921 task->tk_status = -EAGAIN;
922 goto out_unlock;
923 }
924 ret = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925out_unlock:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400926 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebust90051ea2013-09-25 12:17:18 -0400927 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928}
929
Trond Myklebuste0ab53d2006-07-27 17:22:50 -0400930void xprt_end_transmit(struct rpc_task *task)
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700931{
Rahul Iyer343952f2009-04-01 09:23:17 -0400932 xprt_release_write(task->tk_rqstp->rq_xprt, task);
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700933}
934
Chuck Lever9903cd12005-08-11 16:25:26 -0400935/**
936 * xprt_transmit - send an RPC request on a transport
937 * @task: controlling RPC task
938 *
939 * We have to copy the iovec because sendmsg fiddles with its contents.
940 */
941void xprt_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 struct rpc_rqst *req = task->tk_rqstp;
944 struct rpc_xprt *xprt = req->rq_xprt;
Andy Adamson15a45202012-02-14 16:19:18 -0500945 int status, numreqs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
Chuck Lever46121cf2007-01-31 12:14:08 -0500947 dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400949 if (!req->rq_reply_bytes_recvd) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400950 if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
951 /*
952 * Add to the list only if we're expecting a reply
953 */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400954 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 /* Update the softirq receive buffer */
956 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
957 sizeof(req->rq_private_buf));
958 /* Add request to the receive list */
959 list_add_tail(&req->rq_list, &xprt->recv);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400960 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 xprt_reset_majortimeo(req);
Trond Myklebust0f9dc2b2005-06-22 17:16:28 +0000962 /* Turn off autodisconnect */
963 del_singleshot_timer_sync(&xprt->timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 }
965 } else if (!req->rq_bytes_sent)
966 return;
967
Chuck Leverff839972010-05-07 13:34:47 -0400968 req->rq_xtime = ktime_get();
Chuck Levera246b012005-08-11 16:25:23 -0400969 status = xprt->ops->send_request(task);
Jeff Layton3705ad62014-10-28 14:24:13 -0400970 trace_xprt_transmit(xprt, req->rq_xid, status);
Trond Myklebustc8485e42009-03-11 14:37:59 -0400971 if (status != 0) {
972 task->tk_status = status;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700973 return;
974 }
Chuck Lever4a068252015-05-11 14:02:25 -0400975 xprt_inject_disconnect(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976
Trond Myklebustc8485e42009-03-11 14:37:59 -0400977 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
Bryan Schumaker468f8612011-04-18 15:57:32 -0400978 task->tk_flags |= RPC_TASK_SENT;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400979 spin_lock_bh(&xprt->transport_lock);
980
981 xprt->ops->set_retrans_timeout(task);
982
Andy Adamson15a45202012-02-14 16:19:18 -0500983 numreqs = atomic_read(&xprt->num_reqs);
984 if (numreqs > xprt->stat.max_slots)
985 xprt->stat.max_slots = numreqs;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400986 xprt->stat.sends++;
987 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
988 xprt->stat.bklog_u += xprt->backlog.qlen;
Andy Adamson15a45202012-02-14 16:19:18 -0500989 xprt->stat.sending_u += xprt->sending.qlen;
990 xprt->stat.pending_u += xprt->pending.qlen;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400991
992 /* Don't race with disconnect */
993 if (!xprt_connected(xprt))
994 task->tk_status = -ENOTCONN;
Trond Myklebust0a660522013-09-25 11:31:54 -0400995 else {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400996 /*
997 * Sleep on the pending queue since
998 * we're expecting a reply.
999 */
Trond Myklebust0a660522013-09-25 11:31:54 -04001000 if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task))
1001 rpc_sleep_on(&xprt->pending, task, xprt_timer);
1002 req->rq_connect_cookie = xprt->connect_cookie;
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001003 }
Trond Myklebustc8485e42009-03-11 14:37:59 -04001004 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005}
1006
Trond Myklebustba60eb22013-04-14 10:49:37 -04001007static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
1008{
1009 set_bit(XPRT_CONGESTED, &xprt->state);
1010 rpc_sleep_on(&xprt->backlog, task, NULL);
1011}
1012
1013static void xprt_wake_up_backlog(struct rpc_xprt *xprt)
1014{
1015 if (rpc_wake_up_next(&xprt->backlog) == NULL)
1016 clear_bit(XPRT_CONGESTED, &xprt->state);
1017}
1018
1019static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
1020{
1021 bool ret = false;
1022
1023 if (!test_bit(XPRT_CONGESTED, &xprt->state))
1024 goto out;
1025 spin_lock(&xprt->reserve_lock);
1026 if (test_bit(XPRT_CONGESTED, &xprt->state)) {
1027 rpc_sleep_on(&xprt->backlog, task, NULL);
1028 ret = true;
1029 }
1030 spin_unlock(&xprt->reserve_lock);
1031out:
1032 return ret;
1033}
1034
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001035static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
1036{
1037 struct rpc_rqst *req = ERR_PTR(-EAGAIN);
1038
1039 if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))
1040 goto out;
1041 req = kzalloc(sizeof(struct rpc_rqst), gfp_flags);
1042 if (req != NULL)
1043 goto out;
1044 atomic_dec(&xprt->num_reqs);
1045 req = ERR_PTR(-ENOMEM);
1046out:
1047 return req;
1048}
1049
1050static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1051{
1052 if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {
1053 kfree(req);
1054 return true;
1055 }
1056 return false;
1057}
1058
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001059void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060{
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001061 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001063 spin_lock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 if (!list_empty(&xprt->free)) {
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001065 req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1066 list_del(&req->rq_list);
1067 goto out_init_req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 }
Jeff Layton6b343092012-05-16 13:30:35 -04001069 req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001070 if (!IS_ERR(req))
1071 goto out_init_req;
1072 switch (PTR_ERR(req)) {
1073 case -ENOMEM:
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001074 dprintk("RPC: dynamic allocation of request slot "
1075 "failed! Retrying\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001076 task->tk_status = -ENOMEM;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001077 break;
1078 case -EAGAIN:
Trond Myklebustba60eb22013-04-14 10:49:37 -04001079 xprt_add_backlog(xprt, task);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001080 dprintk("RPC: waiting for request slot\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001081 default:
1082 task->tk_status = -EAGAIN;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001083 }
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001084 spin_unlock(&xprt->reserve_lock);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001085 return;
1086out_init_req:
1087 task->tk_status = 0;
1088 task->tk_rqstp = req;
1089 xprt_request_init(task, xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001090 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091}
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001092EXPORT_SYMBOL_GPL(xprt_alloc_slot);
1093
1094void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
1095{
1096 /* Note: grabbing the xprt_lock_write() ensures that we throttle
1097 * new slot allocation if the transport is congested (i.e. when
1098 * reconnecting a stream transport or when out of socket write
1099 * buffer space).
1100 */
1101 if (xprt_lock_write(xprt, task)) {
1102 xprt_alloc_slot(xprt, task);
1103 xprt_release_write(xprt, task);
1104 }
1105}
1106EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001108static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1109{
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001110 spin_lock(&xprt->reserve_lock);
Trond Myklebustc25573b2011-12-01 14:16:17 -05001111 if (!xprt_dynamic_free_slot(xprt, req)) {
1112 memset(req, 0, sizeof(*req)); /* mark unused */
1113 list_add(&req->rq_list, &xprt->free);
1114 }
Trond Myklebustba60eb22013-04-14 10:49:37 -04001115 xprt_wake_up_backlog(xprt);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001116 spin_unlock(&xprt->reserve_lock);
1117}
1118
Trond Myklebust21de0a92011-07-17 16:57:32 -04001119static void xprt_free_all_slots(struct rpc_xprt *xprt)
1120{
1121 struct rpc_rqst *req;
1122 while (!list_empty(&xprt->free)) {
1123 req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list);
1124 list_del(&req->rq_list);
1125 kfree(req);
1126 }
1127}
1128
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001129struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
1130 unsigned int num_prealloc,
1131 unsigned int max_alloc)
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001132{
1133 struct rpc_xprt *xprt;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001134 struct rpc_rqst *req;
1135 int i;
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001136
1137 xprt = kzalloc(size, GFP_KERNEL);
1138 if (xprt == NULL)
1139 goto out;
1140
Trond Myklebust21de0a92011-07-17 16:57:32 -04001141 xprt_init(xprt, net);
1142
1143 for (i = 0; i < num_prealloc; i++) {
1144 req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
1145 if (!req)
wangweidong83131642013-10-15 11:44:30 +08001146 goto out_free;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001147 list_add(&req->rq_list, &xprt->free);
1148 }
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001149 if (max_alloc > num_prealloc)
1150 xprt->max_reqs = max_alloc;
1151 else
1152 xprt->max_reqs = num_prealloc;
1153 xprt->min_reqs = num_prealloc;
1154 atomic_set(&xprt->num_reqs, num_prealloc);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001155
1156 return xprt;
1157
1158out_free:
Trond Myklebust21de0a92011-07-17 16:57:32 -04001159 xprt_free(xprt);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001160out:
1161 return NULL;
1162}
1163EXPORT_SYMBOL_GPL(xprt_alloc);
1164
Pavel Emelyanove204e622010-09-29 16:03:13 +04001165void xprt_free(struct rpc_xprt *xprt)
1166{
Pavel Emelyanov37aa2132010-09-29 16:05:43 +04001167 put_net(xprt->xprt_net);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001168 xprt_free_all_slots(xprt);
Pavel Emelyanove204e622010-09-29 16:03:13 +04001169 kfree(xprt);
1170}
1171EXPORT_SYMBOL_GPL(xprt_free);
1172
Chuck Lever9903cd12005-08-11 16:25:26 -04001173/**
1174 * xprt_reserve - allocate an RPC request slot
1175 * @task: RPC task requesting a slot allocation
1176 *
Trond Myklebustba60eb22013-04-14 10:49:37 -04001177 * If the transport is marked as being congested, or if no more
1178 * slots are available, place the task on the transport's
Chuck Lever9903cd12005-08-11 16:25:26 -04001179 * backlog queue.
1180 */
1181void xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182{
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001183 struct rpc_xprt *xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001185 task->tk_status = 0;
1186 if (task->tk_rqstp != NULL)
1187 return;
1188
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001189 task->tk_timeout = 0;
1190 task->tk_status = -EAGAIN;
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001191 rcu_read_lock();
1192 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustba60eb22013-04-14 10:49:37 -04001193 if (!xprt_throttle_congested(xprt, task))
1194 xprt->ops->alloc_slot(xprt, task);
1195 rcu_read_unlock();
1196}
1197
1198/**
1199 * xprt_retry_reserve - allocate an RPC request slot
1200 * @task: RPC task requesting a slot allocation
1201 *
1202 * If no more slots are available, place the task on the transport's
1203 * backlog queue.
1204 * Note that the only difference with xprt_reserve is that we now
1205 * ignore the value of the XPRT_CONGESTED flag.
1206 */
1207void xprt_retry_reserve(struct rpc_task *task)
1208{
1209 struct rpc_xprt *xprt;
1210
1211 task->tk_status = 0;
1212 if (task->tk_rqstp != NULL)
1213 return;
1214
1215 task->tk_timeout = 0;
1216 task->tk_status = -EAGAIN;
1217 rcu_read_lock();
1218 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001219 xprt->ops->alloc_slot(xprt, task);
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001220 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221}
1222
Alexey Dobriyand8ed0292006-09-26 22:29:38 -07001223static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224{
Eric Dumazet0eae88f2010-04-20 19:06:52 -07001225 return (__force __be32)xprt->xid++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226}
1227
1228static inline void xprt_init_xid(struct rpc_xprt *xprt)
1229{
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -05001230 xprt->xid = prandom_u32();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231}
1232
Chuck Lever9903cd12005-08-11 16:25:26 -04001233static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234{
1235 struct rpc_rqst *req = task->tk_rqstp;
1236
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001237 INIT_LIST_HEAD(&req->rq_list);
Trond Myklebustba7392b2007-12-20 16:03:55 -05001238 req->rq_timeout = task->tk_client->cl_timeout->to_initval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 req->rq_task = task;
1240 req->rq_xprt = xprt;
Chuck Lever02107142006-01-03 09:55:49 +01001241 req->rq_buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 req->rq_xid = xprt_alloc_xid(xprt);
Trond Myklebust0a660522013-09-25 11:31:54 -04001243 req->rq_connect_cookie = xprt->connect_cookie - 1;
Trond Myklebust92551942013-09-27 11:28:40 -04001244 req->rq_bytes_sent = 0;
1245 req->rq_snd_buf.len = 0;
1246 req->rq_snd_buf.buflen = 0;
1247 req->rq_rcv_buf.len = 0;
1248 req->rq_rcv_buf.buflen = 0;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001249 req->rq_release_snd_buf = NULL;
Trond Myklebustda458282006-08-31 15:44:52 -04001250 xprt_reset_majortimeo(req);
Chuck Lever46121cf2007-01-31 12:14:08 -05001251 dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 req, ntohl(req->rq_xid));
1253}
1254
Chuck Lever9903cd12005-08-11 16:25:26 -04001255/**
1256 * xprt_release - release an RPC request slot
1257 * @task: task which is finished with the slot
1258 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 */
Chuck Lever9903cd12005-08-11 16:25:26 -04001260void xprt_release(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261{
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001262 struct rpc_xprt *xprt;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001263 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264
Trond Myklebust87ed5002013-01-07 14:30:46 -05001265 if (req == NULL) {
1266 if (task->tk_client) {
1267 rcu_read_lock();
1268 xprt = rcu_dereference(task->tk_client->cl_xprt);
1269 if (xprt->snd_task == task)
1270 xprt_release_write(xprt, task);
1271 rcu_read_unlock();
1272 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273 return;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001274 }
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001275
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001276 xprt = req->rq_xprt;
Weston Andros Adamson0a702192012-02-17 13:15:24 -05001277 if (task->tk_ops->rpc_count_stats != NULL)
1278 task->tk_ops->rpc_count_stats(task, task->tk_calldata);
1279 else if (task->tk_client)
1280 rpc_count_iostats(task, task->tk_client->cl_metrics);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001281 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -07001282 xprt->ops->release_xprt(xprt, task);
Chuck Levera58dd392005-08-25 16:25:53 -07001283 if (xprt->ops->release_request)
1284 xprt->ops->release_request(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 if (!list_empty(&req->rq_list))
1286 list_del(&req->rq_list);
1287 xprt->last_used = jiffies;
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001288 if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
Chuck Levera246b012005-08-11 16:25:23 -04001289 mod_timer(&xprt->timer,
Chuck Lever03bf4b72005-08-25 16:25:55 -07001290 xprt->last_used + xprt->idle_timeout);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001291 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001292 if (req->rq_buffer)
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001293 xprt->ops->buf_free(req->rq_buffer);
Chuck Lever4a068252015-05-11 14:02:25 -04001294 xprt_inject_disconnect(xprt);
Trond Myklebusta17c2152010-07-31 14:29:08 -04001295 if (req->rq_cred != NULL)
1296 put_rpccred(req->rq_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 task->tk_rqstp = NULL;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001298 if (req->rq_release_snd_buf)
1299 req->rq_release_snd_buf(req);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001300
Chuck Lever46121cf2007-01-31 12:14:08 -05001301 dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001302 if (likely(!bc_prealloc(req)))
1303 xprt_free_slot(xprt, req);
1304 else
Trond Myklebustc9acb422010-03-19 15:36:22 -04001305 xprt_free_bc_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306}
1307
Trond Myklebust21de0a92011-07-17 16:57:32 -04001308static void xprt_init(struct rpc_xprt *xprt, struct net *net)
Chuck Leverc2866762006-08-22 20:06:20 -04001309{
Trond Myklebust21de0a92011-07-17 16:57:32 -04001310 atomic_set(&xprt->count, 1);
Chuck Leverc2866762006-08-22 20:06:20 -04001311
1312 spin_lock_init(&xprt->transport_lock);
1313 spin_lock_init(&xprt->reserve_lock);
1314
1315 INIT_LIST_HEAD(&xprt->free);
1316 INIT_LIST_HEAD(&xprt->recv);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001317#if defined(CONFIG_SUNRPC_BACKCHANNEL)
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001318 spin_lock_init(&xprt->bc_pa_lock);
1319 INIT_LIST_HEAD(&xprt->bc_pa_list);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001320#endif /* CONFIG_SUNRPC_BACKCHANNEL */
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001321
Chuck Leverc2866762006-08-22 20:06:20 -04001322 xprt->last_used = jiffies;
1323 xprt->cwnd = RPC_INITCWND;
Chuck Levera5090502007-03-29 16:48:04 -04001324 xprt->bind_index = 0;
Chuck Leverc2866762006-08-22 20:06:20 -04001325
1326 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
1327 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
Trond Myklebust34006ce2011-07-17 18:11:34 -04001328 rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending");
Chuck Leverc2866762006-08-22 20:06:20 -04001329 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1330
Chuck Leverc2866762006-08-22 20:06:20 -04001331 xprt_init_xid(xprt);
1332
Trond Myklebust21de0a92011-07-17 16:57:32 -04001333 xprt->xprt_net = get_net(net);
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001334}
1335
1336/**
1337 * xprt_create_transport - create an RPC transport
1338 * @args: rpc transport creation arguments
1339 *
1340 */
1341struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
1342{
1343 struct rpc_xprt *xprt;
1344 struct xprt_class *t;
1345
1346 spin_lock(&xprt_list_lock);
1347 list_for_each_entry(t, &xprt_list, list) {
1348 if (t->ident == args->ident) {
1349 spin_unlock(&xprt_list_lock);
1350 goto found;
1351 }
1352 }
1353 spin_unlock(&xprt_list_lock);
Chuck Lever3c45ddf2014-07-16 15:38:32 -04001354 dprintk("RPC: transport (%d) not supported\n", args->ident);
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001355 return ERR_PTR(-EIO);
1356
1357found:
1358 xprt = t->setup(args);
1359 if (IS_ERR(xprt)) {
1360 dprintk("RPC: xprt_create_transport: failed, %ld\n",
1361 -PTR_ERR(xprt));
Trond Myklebust21de0a92011-07-17 16:57:32 -04001362 goto out;
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001363 }
J. Bruce Fields33d90ac2013-04-11 15:06:36 -04001364 if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
1365 xprt->idle_timeout = 0;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001366 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
1367 if (xprt_has_timer(xprt))
1368 setup_timer(&xprt->timer, xprt_init_autodisconnect,
1369 (unsigned long)xprt);
1370 else
1371 init_timer(&xprt->timer);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001372
1373 if (strlen(args->servername) > RPC_MAXNETNAMELEN) {
1374 xprt_destroy(xprt);
1375 return ERR_PTR(-EINVAL);
1376 }
1377 xprt->servername = kstrdup(args->servername, GFP_KERNEL);
1378 if (xprt->servername == NULL) {
1379 xprt_destroy(xprt);
1380 return ERR_PTR(-ENOMEM);
1381 }
1382
Jeff Layton3f940092015-03-31 12:03:28 -04001383 rpc_xprt_debugfs_register(xprt);
Jeff Layton388f0c72014-11-26 14:44:44 -05001384
Chuck Lever46121cf2007-01-31 12:14:08 -05001385 dprintk("RPC: created transport %p with %u slots\n", xprt,
Chuck Leverc2866762006-08-22 20:06:20 -04001386 xprt->max_reqs);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001387out:
Chuck Leverc2866762006-08-22 20:06:20 -04001388 return xprt;
1389}
1390
Chuck Lever9903cd12005-08-11 16:25:26 -04001391/**
1392 * xprt_destroy - destroy an RPC transport, killing off all requests.
Trond Myklebusta8de2402011-03-15 19:56:30 -04001393 * @xprt: transport to destroy
Chuck Lever9903cd12005-08-11 16:25:26 -04001394 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 */
Trond Myklebusta8de2402011-03-15 19:56:30 -04001396static void xprt_destroy(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397{
Chuck Lever46121cf2007-01-31 12:14:08 -05001398 dprintk("RPC: destroying transport %p\n", xprt);
Trond Myklebust79234c32015-09-18 15:53:24 -04001399
1400 /* Exclude transport connect/disconnect handlers */
1401 wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE);
1402
Trond Myklebust0065db32006-01-03 09:55:56 +01001403 del_timer_sync(&xprt->timer);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001404
Jeff Layton388f0c72014-11-26 14:44:44 -05001405 rpc_xprt_debugfs_unregister(xprt);
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001406 rpc_destroy_wait_queue(&xprt->binding);
1407 rpc_destroy_wait_queue(&xprt->pending);
1408 rpc_destroy_wait_queue(&xprt->sending);
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001409 rpc_destroy_wait_queue(&xprt->backlog);
J. Bruce Fieldsc3ae62ae2010-08-03 17:22:20 -04001410 cancel_work_sync(&xprt->task_cleanup);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001411 kfree(xprt->servername);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001412 /*
1413 * Tear down transport state and free the rpc_xprt
1414 */
Chuck Levera246b012005-08-11 16:25:23 -04001415 xprt->ops->destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001416}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001418/**
1419 * xprt_put - release a reference to an RPC transport.
1420 * @xprt: pointer to the transport
1421 *
1422 */
1423void xprt_put(struct rpc_xprt *xprt)
1424{
Trond Myklebusta8de2402011-03-15 19:56:30 -04001425 if (atomic_dec_and_test(&xprt->count))
1426 xprt_destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001427}
Chuck Lever5d252f92016-01-07 14:50:10 -05001428EXPORT_SYMBOL_GPL(xprt_put);