blob: 89d051de6b3e8da4fb439e9e2380cba71d5c716e [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 Myklebust92551942013-09-27 11:28:40 -0400208 if (req != NULL)
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400209 req->rq_ntrans++;
j223yang@asset.uwaterloo.ca4d4a76f2011-03-10 12:40:28 -0500210
Chuck Lever12a80462005-08-25 16:25:51 -0700211 return 1;
212
213out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500214 dprintk("RPC: %5u failed to lock transport %p\n",
Chuck Lever12a80462005-08-25 16:25:51 -0700215 task->tk_pid, xprt);
216 task->tk_timeout = 0;
217 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400218 if (req == NULL)
219 priority = RPC_PRIORITY_LOW;
220 else if (!req->rq_ntrans)
221 priority = RPC_PRIORITY_NORMAL;
Chuck Lever12a80462005-08-25 16:25:51 -0700222 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400223 priority = RPC_PRIORITY_HIGH;
224 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Chuck Lever12a80462005-08-25 16:25:51 -0700225 return 0;
226}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400227EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
Chuck Lever12a80462005-08-25 16:25:51 -0700228
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100229static void xprt_clear_locked(struct rpc_xprt *xprt)
230{
231 xprt->snd_task = NULL;
Trond Myklebustd19751e2012-09-11 17:21:25 -0400232 if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
Peter Zijlstra4e857c52014-03-17 18:06:10 +0100233 smp_mb__before_atomic();
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100234 clear_bit(XPRT_LOCKED, &xprt->state);
Peter Zijlstra4e857c52014-03-17 18:06:10 +0100235 smp_mb__after_atomic();
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100236 } else
Trond Myklebustc1384c92007-06-14 18:00:42 -0400237 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100238}
239
Chuck Lever12a80462005-08-25 16:25:51 -0700240/*
241 * xprt_reserve_xprt_cong - serialize write access to transports
242 * @task: task that is requesting access to the transport
243 *
244 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
245 * integrated into the decision of whether a request is allowed to be
246 * woken up and given access to the transport.
247 */
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400248int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
Chuck Lever12a80462005-08-25 16:25:51 -0700249{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400251 int priority;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Chuck Lever2226feb2005-08-11 16:25:38 -0400253 if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 if (task == xprt->snd_task)
255 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 goto out_sleep;
257 }
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400258 if (req == NULL) {
259 xprt->snd_task = task;
260 return 1;
261 }
Chuck Lever12a80462005-08-25 16:25:51 -0700262 if (__xprt_get_cong(xprt, task)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400264 req->rq_ntrans++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return 1;
266 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100267 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268out_sleep:
Chuck Lever46121cf2007-01-31 12:14:08 -0500269 dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 task->tk_timeout = 0;
271 task->tk_status = -EAGAIN;
Trond Myklebust34006ce2011-07-17 18:11:34 -0400272 if (req == NULL)
273 priority = RPC_PRIORITY_LOW;
274 else if (!req->rq_ntrans)
275 priority = RPC_PRIORITY_NORMAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 else
Trond Myklebust34006ce2011-07-17 18:11:34 -0400277 priority = RPC_PRIORITY_HIGH;
278 rpc_sleep_on_priority(&xprt->sending, task, NULL, priority);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return 0;
280}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400281EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
Chuck Lever12a80462005-08-25 16:25:51 -0700283static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284{
285 int retval;
286
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400287 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400288 retval = xprt->ops->reserve_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400289 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 return retval;
291}
292
Trond Myklebust961a8282012-01-17 22:57:37 -0500293static bool __xprt_lock_write_func(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294{
Trond Myklebust961a8282012-01-17 22:57:37 -0500295 struct rpc_xprt *xprt = data;
Chuck Lever49e9a892005-08-25 16:25:51 -0700296 struct rpc_rqst *req;
297
Chuck Lever49e9a892005-08-25 16:25:51 -0700298 req = task->tk_rqstp;
299 xprt->snd_task = task;
Trond Myklebust92551942013-09-27 11:28:40 -0400300 if (req)
Chuck Lever49e9a892005-08-25 16:25:51 -0700301 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500302 return true;
303}
Chuck Lever49e9a892005-08-25 16:25:51 -0700304
Trond Myklebust961a8282012-01-17 22:57:37 -0500305static void __xprt_lock_write_next(struct rpc_xprt *xprt)
306{
307 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
308 return;
309
310 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt))
311 return;
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100312 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700313}
314
Trond Myklebust961a8282012-01-17 22:57:37 -0500315static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data)
Chuck Lever49e9a892005-08-25 16:25:51 -0700316{
Trond Myklebust961a8282012-01-17 22:57:37 -0500317 struct rpc_xprt *xprt = data;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400318 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400320 req = task->tk_rqstp;
321 if (req == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 xprt->snd_task = task;
Trond Myklebust961a8282012-01-17 22:57:37 -0500323 return true;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400324 }
325 if (__xprt_get_cong(xprt, task)) {
326 xprt->snd_task = task;
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -0400327 req->rq_ntrans++;
Trond Myklebust961a8282012-01-17 22:57:37 -0500328 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 }
Trond Myklebust961a8282012-01-17 22:57:37 -0500330 return false;
331}
332
333static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
334{
335 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
336 return;
337 if (RPCXPRT_CONGESTED(xprt))
338 goto out_unlock;
339 if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt))
340 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341out_unlock:
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100342 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343}
344
Chuck Lever49e9a892005-08-25 16:25:51 -0700345/**
346 * xprt_release_xprt - allow other requests to use a transport
347 * @xprt: transport with other tasks potentially waiting
348 * @task: task that is releasing access to the transport
349 *
350 * Note that "task" can be NULL. No congestion control is provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 */
Chuck Lever49e9a892005-08-25 16:25:51 -0700352void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
354 if (xprt->snd_task == task) {
Trond Myklebustee071ef2013-09-27 11:09:53 -0400355 if (task != NULL) {
356 struct rpc_rqst *req = task->tk_rqstp;
357 if (req != NULL)
358 req->rq_bytes_sent = 0;
359 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100360 xprt_clear_locked(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 __xprt_lock_write_next(xprt);
362 }
363}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400364EXPORT_SYMBOL_GPL(xprt_release_xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
Chuck Lever49e9a892005-08-25 16:25:51 -0700366/**
367 * xprt_release_xprt_cong - allow other requests to use a transport
368 * @xprt: transport with other tasks potentially waiting
369 * @task: task that is releasing access to the transport
370 *
371 * Note that "task" can be NULL. Another task is awoken to use the
372 * transport if the transport's congestion window allows it.
373 */
374void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
375{
376 if (xprt->snd_task == task) {
Trond Myklebustee071ef2013-09-27 11:09:53 -0400377 if (task != NULL) {
378 struct rpc_rqst *req = task->tk_rqstp;
379 if (req != NULL)
380 req->rq_bytes_sent = 0;
381 }
Trond Myklebust632e3bd2006-01-03 09:55:55 +0100382 xprt_clear_locked(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700383 __xprt_lock_write_next_cong(xprt);
384 }
385}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400386EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
Chuck Lever49e9a892005-08-25 16:25:51 -0700387
388static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389{
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400390 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -0700391 xprt->ops->release_xprt(xprt, task);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400392 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393}
394
395/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 * Van Jacobson congestion avoidance. Check if the congestion window
397 * overflowed. Put the task to sleep if this is the case.
398 */
399static int
400__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
401{
402 struct rpc_rqst *req = task->tk_rqstp;
403
404 if (req->rq_cong)
405 return 1;
Chuck Lever46121cf2007-01-31 12:14:08 -0500406 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 task->tk_pid, xprt->cong, xprt->cwnd);
408 if (RPCXPRT_CONGESTED(xprt))
409 return 0;
410 req->rq_cong = 1;
411 xprt->cong += RPC_CWNDSCALE;
412 return 1;
413}
414
415/*
416 * Adjust the congestion window, and wake up the next task
417 * that has been sleeping due to congestion
418 */
419static void
420__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
421{
422 if (!req->rq_cong)
423 return;
424 req->rq_cong = 0;
425 xprt->cong -= RPC_CWNDSCALE;
Chuck Lever49e9a892005-08-25 16:25:51 -0700426 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427}
428
Chuck Lever46c0ee82005-08-25 16:25:52 -0700429/**
Chuck Levera58dd392005-08-25 16:25:53 -0700430 * xprt_release_rqst_cong - housekeeping when request is complete
431 * @task: RPC request that recently completed
432 *
433 * Useful for transports that require congestion control.
434 */
435void xprt_release_rqst_cong(struct rpc_task *task)
436{
Trond Myklebusta4f08352013-01-08 09:10:21 -0500437 struct rpc_rqst *req = task->tk_rqstp;
438
439 __xprt_put_cong(req->rq_xprt, req);
Chuck Levera58dd392005-08-25 16:25:53 -0700440}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400441EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
Chuck Levera58dd392005-08-25 16:25:53 -0700442
443/**
Chuck Lever46c0ee82005-08-25 16:25:52 -0700444 * xprt_adjust_cwnd - adjust transport congestion window
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500445 * @xprt: pointer to xprt
Chuck Lever46c0ee82005-08-25 16:25:52 -0700446 * @task: recently completed RPC request used to adjust window
447 * @result: result code of completed RPC request
448 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
450 */
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500451void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700453 struct rpc_rqst *req = task->tk_rqstp;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700454 unsigned long cwnd = xprt->cwnd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 if (result >= 0 && cwnd <= xprt->cong) {
457 /* The (cwnd >> 1) term makes sure
458 * the result gets rounded properly. */
459 cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
460 if (cwnd > RPC_MAXCWND(xprt))
461 cwnd = RPC_MAXCWND(xprt);
Chuck Lever49e9a892005-08-25 16:25:51 -0700462 __xprt_lock_write_next_cong(xprt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 } else if (result == -ETIMEDOUT) {
464 cwnd >>= 1;
465 if (cwnd < RPC_CWNDSCALE)
466 cwnd = RPC_CWNDSCALE;
467 }
Chuck Lever46121cf2007-01-31 12:14:08 -0500468 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 xprt->cong, xprt->cwnd, cwnd);
470 xprt->cwnd = cwnd;
Chuck Lever46c0ee82005-08-25 16:25:52 -0700471 __xprt_put_cong(xprt, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400473EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474
Chuck Lever44fbac22005-08-11 16:25:44 -0400475/**
476 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
477 * @xprt: transport with waiting tasks
478 * @status: result code to plant in each task before waking it
479 *
480 */
481void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
482{
483 if (status < 0)
484 rpc_wake_up_status(&xprt->pending, status);
485 else
486 rpc_wake_up(&xprt->pending);
487}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400488EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
Chuck Lever44fbac22005-08-11 16:25:44 -0400489
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400490/**
491 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
492 * @task: task to be put to sleep
Randy Dunlap0b80ae42008-04-26 22:59:02 -0700493 * @action: function pointer to be executed after wait
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500494 *
495 * Note that we only set the timer for the case of RPC_IS_SOFT(), since
496 * we don't in general want to force a socket disconnection due to
497 * an incomplete RPC call transmission.
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400498 */
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400499void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400500{
501 struct rpc_rqst *req = task->tk_rqstp;
502 struct rpc_xprt *xprt = req->rq_xprt;
503
Trond Myklebusta9a6b522013-02-22 14:57:57 -0500504 task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0;
Trond Myklebustb6ddf642008-04-17 18:52:19 -0400505 rpc_sleep_on(&xprt->pending, task, action);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400506}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400507EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400508
509/**
510 * xprt_write_space - wake the task waiting for transport output buffer space
511 * @xprt: transport with waiting tasks
512 *
513 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
514 */
515void xprt_write_space(struct rpc_xprt *xprt)
516{
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400517 spin_lock_bh(&xprt->transport_lock);
518 if (xprt->snd_task) {
Chuck Lever46121cf2007-01-31 12:14:08 -0500519 dprintk("RPC: write space: waking waiting task on "
520 "xprt %p\n", xprt);
Trond Myklebustfda13932008-02-22 16:34:12 -0500521 rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400522 }
523 spin_unlock_bh(&xprt->transport_lock);
524}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400525EXPORT_SYMBOL_GPL(xprt_write_space);
Chuck Leverc7b2cae2005-08-11 16:25:50 -0400526
Chuck Leverfe3aca22005-08-25 16:25:50 -0700527/**
528 * xprt_set_retrans_timeout_def - set a request's retransmit timeout
529 * @task: task whose timeout is to be set
530 *
531 * Set a request's retransmit timeout based on the transport's
532 * default timeout parameters. Used by transports that don't adjust
533 * the retransmit timeout based on round-trip time estimation.
534 */
535void xprt_set_retrans_timeout_def(struct rpc_task *task)
536{
537 task->tk_timeout = task->tk_rqstp->rq_timeout;
538}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400539EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700540
Ben Hutchings2c530402012-07-10 10:55:09 +0000541/**
Chuck Leverfe3aca22005-08-25 16:25:50 -0700542 * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
543 * @task: task whose timeout is to be set
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800544 *
Chuck Leverfe3aca22005-08-25 16:25:50 -0700545 * Set a request's retransmit timeout using the RTT estimator.
546 */
547void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
548{
549 int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500550 struct rpc_clnt *clnt = task->tk_client;
551 struct rpc_rtt *rtt = clnt->cl_rtt;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700552 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500553 unsigned long max_timeout = clnt->cl_timeout->to_maxval;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700554
555 task->tk_timeout = rpc_calc_rto(rtt, timer);
556 task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
557 if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
558 task->tk_timeout = max_timeout;
559}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400560EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
Chuck Leverfe3aca22005-08-25 16:25:50 -0700561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562static void xprt_reset_majortimeo(struct rpc_rqst *req)
563{
Trond Myklebustba7392b2007-12-20 16:03:55 -0500564 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566 req->rq_majortimeo = req->rq_timeout;
567 if (to->to_exponential)
568 req->rq_majortimeo <<= to->to_retries;
569 else
570 req->rq_majortimeo += to->to_increment * to->to_retries;
571 if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
572 req->rq_majortimeo = to->to_maxval;
573 req->rq_majortimeo += jiffies;
574}
575
Chuck Lever9903cd12005-08-11 16:25:26 -0400576/**
577 * xprt_adjust_timeout - adjust timeout values for next retransmit
578 * @req: RPC request containing parameters to use for the adjustment
579 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 */
581int xprt_adjust_timeout(struct rpc_rqst *req)
582{
583 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebustba7392b2007-12-20 16:03:55 -0500584 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 int status = 0;
586
587 if (time_before(jiffies, req->rq_majortimeo)) {
588 if (to->to_exponential)
589 req->rq_timeout <<= 1;
590 else
591 req->rq_timeout += to->to_increment;
592 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
593 req->rq_timeout = to->to_maxval;
594 req->rq_retries++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 } else {
596 req->rq_timeout = to->to_initval;
597 req->rq_retries = 0;
598 xprt_reset_majortimeo(req);
599 /* Reset the RTT counters == "slow start" */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400600 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400602 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 status = -ETIMEDOUT;
604 }
605
606 if (req->rq_timeout == 0) {
607 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
608 req->rq_timeout = 5 * HZ;
609 }
610 return status;
611}
612
David Howells65f27f32006-11-22 14:55:48 +0000613static void xprt_autoclose(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614{
David Howells65f27f32006-11-22 14:55:48 +0000615 struct rpc_xprt *xprt =
616 container_of(work, struct rpc_xprt, task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
Chuck Levera246b012005-08-11 16:25:23 -0400618 xprt->ops->close(xprt);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500619 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 xprt_release_write(xprt, NULL);
621}
622
Chuck Lever9903cd12005-08-11 16:25:26 -0400623/**
Trond Myklebust62da3b22007-11-06 18:44:20 -0500624 * xprt_disconnect_done - mark a transport as disconnected
Chuck Lever9903cd12005-08-11 16:25:26 -0400625 * @xprt: transport to flag for disconnect
626 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 */
Trond Myklebust62da3b22007-11-06 18:44:20 -0500628void xprt_disconnect_done(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629{
Chuck Lever46121cf2007-01-31 12:14:08 -0500630 dprintk("RPC: disconnected transport %p\n", xprt);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400631 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 xprt_clear_connected(xprt);
Trond Myklebust2a491992009-03-11 14:38:00 -0400633 xprt_wake_pending_tasks(xprt, -EAGAIN);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400634 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635}
Trond Myklebust62da3b22007-11-06 18:44:20 -0500636EXPORT_SYMBOL_GPL(xprt_disconnect_done);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637
Trond Myklebust66af1e52007-11-06 10:18:36 -0500638/**
639 * xprt_force_disconnect - force a transport to disconnect
640 * @xprt: transport to disconnect
641 *
642 */
643void xprt_force_disconnect(struct rpc_xprt *xprt)
644{
645 /* Don't race with the test_bit() in xprt_clear_locked() */
646 spin_lock_bh(&xprt->transport_lock);
647 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
648 /* Try to schedule an autoclose RPC call */
649 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
650 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400651 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust66af1e52007-11-06 10:18:36 -0500652 spin_unlock_bh(&xprt->transport_lock);
653}
Trond Myklebust66af1e52007-11-06 10:18:36 -0500654
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400655/**
656 * xprt_conditional_disconnect - force a transport to disconnect
657 * @xprt: transport to disconnect
658 * @cookie: 'connection cookie'
659 *
660 * This attempts to break the connection if and only if 'cookie' matches
661 * the current transport 'connection cookie'. It ensures that we don't
662 * try to break the connection more than once when we need to retransmit
663 * a batch of RPC requests.
664 *
665 */
666void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
667{
668 /* Don't race with the test_bit() in xprt_clear_locked() */
669 spin_lock_bh(&xprt->transport_lock);
670 if (cookie != xprt->connect_cookie)
671 goto out;
672 if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
673 goto out;
674 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
675 /* Try to schedule an autoclose RPC call */
676 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
677 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Trond Myklebust2a491992009-03-11 14:38:00 -0400678 xprt_wake_pending_tasks(xprt, -EAGAIN);
Trond Myklebust7c1d71c2008-04-17 16:52:57 -0400679out:
680 spin_unlock_bh(&xprt->transport_lock);
681}
682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683static void
684xprt_init_autodisconnect(unsigned long data)
685{
686 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
687
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400688 spin_lock(&xprt->transport_lock);
Trond Myklebustd19751e2012-09-11 17:21:25 -0400689 if (!list_empty(&xprt->recv))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 goto out_abort;
Chuck Lever2226feb2005-08-11 16:25:38 -0400691 if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 goto out_abort;
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400693 spin_unlock(&xprt->transport_lock);
Trond Myklebustf75e6742009-04-21 17:18:20 -0400694 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
695 queue_work(rpciod_workqueue, &xprt->task_cleanup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 return;
697out_abort:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400698 spin_unlock(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699}
700
Chuck Lever9903cd12005-08-11 16:25:26 -0400701/**
702 * xprt_connect - schedule a transport connect operation
703 * @task: RPC task that is requesting the connect
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 *
705 */
706void xprt_connect(struct rpc_task *task)
707{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500708 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Chuck Lever46121cf2007-01-31 12:14:08 -0500710 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 xprt, (xprt_connected(xprt) ? "is" : "is not"));
712
Chuck Leverec739ef2006-08-22 20:06:15 -0400713 if (!xprt_bound(xprt)) {
Trond Myklebust01d37c42009-03-11 14:09:39 -0400714 task->tk_status = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 return;
716 }
717 if (!xprt_lock_write(xprt, task))
718 return;
Trond Myklebustfeb8ca32009-12-03 08:10:17 -0500719
720 if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
721 xprt->ops->close(xprt);
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 if (xprt_connected(xprt))
Chuck Levera246b012005-08-11 16:25:23 -0400724 xprt_release_write(xprt, task);
725 else {
Dan Carpenter87e3c052012-02-01 10:46:20 +0300726 task->tk_rqstp->rq_bytes_sent = 0;
Trond Myklebusta8ce4a82010-04-16 16:42:12 -0400727 task->tk_timeout = task->tk_rqstp->rq_timeout;
Trond Myklebust5d008372008-02-22 16:34:17 -0500728 rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
Trond Myklebust0b9e7942010-04-16 16:41:57 -0400729
730 if (test_bit(XPRT_CLOSING, &xprt->state))
731 return;
732 if (xprt_test_and_set_connecting(xprt))
733 return;
Chuck Lever262ca072006-03-20 13:44:16 -0500734 xprt->stat.connect_start = jiffies;
Trond Myklebust1b092092013-01-08 09:26:49 -0500735 xprt->ops->connect(xprt, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737}
738
Chuck Lever9903cd12005-08-11 16:25:26 -0400739static void xprt_connect_status(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740{
Trond Myklebustad2368d2013-01-08 10:08:33 -0500741 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
Chuck Levercd983ef2008-06-11 17:56:13 -0400743 if (task->tk_status == 0) {
Chuck Lever262ca072006-03-20 13:44:16 -0500744 xprt->stat.connect_count++;
745 xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
Chuck Lever46121cf2007-01-31 12:14:08 -0500746 dprintk("RPC: %5u xprt_connect_status: connection established\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 task->tk_pid);
748 return;
749 }
750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 switch (task->tk_status) {
Trond Myklebust0fe8d042013-12-31 13:13:30 -0500752 case -ECONNREFUSED:
753 case -ECONNRESET:
754 case -ECONNABORTED:
755 case -ENETUNREACH:
756 case -EHOSTUNREACH:
Trond Myklebust2a491992009-03-11 14:38:00 -0400757 case -EAGAIN:
758 dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
Chuck Lever23475d62005-08-11 16:25:08 -0400759 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 case -ETIMEDOUT:
Chuck Lever46121cf2007-01-31 12:14:08 -0500761 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
762 "out\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 break;
764 default:
Chuck Lever46121cf2007-01-31 12:14:08 -0500765 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
766 "server %s\n", task->tk_pid, -task->tk_status,
Trond Myklebust4e0038b2012-03-01 17:01:05 -0500767 xprt->servername);
Chuck Lever23475d62005-08-11 16:25:08 -0400768 xprt_release_write(xprt, task);
769 task->tk_status = -EIO;
Chuck Lever23475d62005-08-11 16:25:08 -0400770 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771}
772
Chuck Lever9903cd12005-08-11 16:25:26 -0400773/**
774 * xprt_lookup_rqst - find an RPC request corresponding to an XID
775 * @xprt: transport on which the original request was transmitted
776 * @xid: RPC XID of incoming reply
777 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700779struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780{
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400781 struct rpc_rqst *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400783 list_for_each_entry(entry, &xprt->recv, rq_list)
Chuck Lever262ca072006-03-20 13:44:16 -0500784 if (entry->rq_xid == xid)
785 return entry;
Chuck Lever46121cf2007-01-31 12:14:08 -0500786
787 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
788 ntohl(xid));
Chuck Lever262ca072006-03-20 13:44:16 -0500789 xprt->stat.bad_xids++;
790 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400792EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400794static void xprt_update_rtt(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795{
Chuck Lever1570c1e2005-08-25 16:25:52 -0700796 struct rpc_rqst *req = task->tk_rqstp;
797 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
Eric Dumazet95c96172012-04-15 05:58:06 +0000798 unsigned int timer = task->tk_msg.rpc_proc->p_timer;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400799 long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
Chuck Lever1570c1e2005-08-25 16:25:52 -0700801 if (timer) {
802 if (req->rq_ntrans == 1)
Chuck Leverff839972010-05-07 13:34:47 -0400803 rpc_update_rtt(rtt, timer, m);
Chuck Lever1570c1e2005-08-25 16:25:52 -0700804 rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 }
Chuck Lever1570c1e2005-08-25 16:25:52 -0700806}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807
Chuck Lever1570c1e2005-08-25 16:25:52 -0700808/**
809 * xprt_complete_rqst - called when reply processing is complete
810 * @task: RPC request that recently completed
811 * @copied: actual number of bytes received from the transport
812 *
813 * Caller holds transport lock.
814 */
815void xprt_complete_rqst(struct rpc_task *task, int copied)
816{
817 struct rpc_rqst *req = task->tk_rqstp;
Trond Myklebustfda13932008-02-22 16:34:12 -0500818 struct rpc_xprt *xprt = req->rq_xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819
Chuck Lever1570c1e2005-08-25 16:25:52 -0700820 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
821 task->tk_pid, ntohl(req->rq_xid), copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
Trond Myklebustfda13932008-02-22 16:34:12 -0500823 xprt->stat.recvs++;
Trond Myklebustd60dbb22010-05-13 12:51:49 -0400824 req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime);
Chuck Leverbbc72ce2010-05-07 13:34:27 -0400825 if (xprt->ops->timer != NULL)
826 xprt_update_rtt(task);
Chuck Leveref759a22006-03-20 13:44:17 -0500827
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 list_del_init(&req->rq_list);
Trond Myklebust1e799b62008-03-21 16:19:41 -0400829 req->rq_private_buf.len = copied;
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400830 /* Ensure all writes are done before we update */
831 /* req->rq_reply_bytes_recvd */
Trond Myklebust43ac3f22006-03-20 13:44:51 -0500832 smp_wmb();
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400833 req->rq_reply_bytes_recvd = copied;
Trond Myklebustfda13932008-02-22 16:34:12 -0500834 rpc_wake_up_queued_task(&xprt->pending, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835}
\"Talpey, Thomas\12444802007-09-10 13:45:36 -0400836EXPORT_SYMBOL_GPL(xprt_complete_rqst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
Chuck Lever46c0ee82005-08-25 16:25:52 -0700838static void xprt_timer(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839{
Chuck Lever46c0ee82005-08-25 16:25:52 -0700840 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 struct rpc_xprt *xprt = req->rq_xprt;
842
Trond Myklebust5d008372008-02-22 16:34:17 -0500843 if (task->tk_status != -ETIMEDOUT)
844 return;
Chuck Lever46121cf2007-01-31 12:14:08 -0500845 dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
Chuck Lever46c0ee82005-08-25 16:25:52 -0700846
Trond Myklebust5d008372008-02-22 16:34:17 -0500847 spin_lock_bh(&xprt->transport_lock);
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400848 if (!req->rq_reply_bytes_recvd) {
Chuck Lever46c0ee82005-08-25 16:25:52 -0700849 if (xprt->ops->timer)
Trond Myklebust6a24dfb2013-01-08 09:48:15 -0500850 xprt->ops->timer(xprt, task);
Trond Myklebust5d008372008-02-22 16:34:17 -0500851 } else
852 task->tk_status = 0;
853 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854}
855
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300856static inline int xprt_has_timer(struct rpc_xprt *xprt)
857{
858 return xprt->idle_timeout != 0;
859}
860
Chuck Lever9903cd12005-08-11 16:25:26 -0400861/**
862 * xprt_prepare_transmit - reserve the transport before sending a request
863 * @task: RPC task about to send a request
864 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 */
Trond Myklebust90051ea2013-09-25 12:17:18 -0400866bool xprt_prepare_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867{
868 struct rpc_rqst *req = task->tk_rqstp;
869 struct rpc_xprt *xprt = req->rq_xprt;
Trond Myklebust90051ea2013-09-25 12:17:18 -0400870 bool ret = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871
Chuck Lever46121cf2007-01-31 12:14:08 -0500872 dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400874 spin_lock_bh(&xprt->transport_lock);
Trond Myklebust8a19a0b2013-09-24 12:00:27 -0400875 if (!req->rq_bytes_sent) {
876 if (req->rq_reply_bytes_recvd) {
877 task->tk_status = req->rq_reply_bytes_recvd;
878 goto out_unlock;
879 }
880 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
881 && xprt_connected(xprt)
882 && req->rq_connect_cookie == xprt->connect_cookie) {
883 xprt->ops->set_retrans_timeout(task);
884 rpc_sleep_on(&xprt->pending, task, xprt_timer);
885 goto out_unlock;
886 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 }
Trond Myklebust90051ea2013-09-25 12:17:18 -0400888 if (!xprt->ops->reserve_xprt(xprt, task)) {
889 task->tk_status = -EAGAIN;
890 goto out_unlock;
891 }
892 ret = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893out_unlock:
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400894 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebust90051ea2013-09-25 12:17:18 -0400895 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896}
897
Trond Myklebuste0ab53d2006-07-27 17:22:50 -0400898void xprt_end_transmit(struct rpc_task *task)
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700899{
Rahul Iyer343952f2009-04-01 09:23:17 -0400900 xprt_release_write(task->tk_rqstp->rq_xprt, task);
Trond Myklebust5e5ce5b2005-10-18 14:20:11 -0700901}
902
Chuck Lever9903cd12005-08-11 16:25:26 -0400903/**
904 * xprt_transmit - send an RPC request on a transport
905 * @task: controlling RPC task
906 *
907 * We have to copy the iovec because sendmsg fiddles with its contents.
908 */
909void xprt_transmit(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 struct rpc_rqst *req = task->tk_rqstp;
912 struct rpc_xprt *xprt = req->rq_xprt;
Andy Adamson15a45202012-02-14 16:19:18 -0500913 int status, numreqs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914
Chuck Lever46121cf2007-01-31 12:14:08 -0500915 dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916
Ricardo Labiagadd2b63d2009-04-01 09:23:28 -0400917 if (!req->rq_reply_bytes_recvd) {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400918 if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
919 /*
920 * Add to the list only if we're expecting a reply
921 */
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400922 spin_lock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 /* Update the softirq receive buffer */
924 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
925 sizeof(req->rq_private_buf));
926 /* Add request to the receive list */
927 list_add_tail(&req->rq_list, &xprt->recv);
Chuck Lever4a0f8c02005-08-11 16:25:32 -0400928 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 xprt_reset_majortimeo(req);
Trond Myklebust0f9dc2b2005-06-22 17:16:28 +0000930 /* Turn off autodisconnect */
931 del_singleshot_timer_sync(&xprt->timer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 }
933 } else if (!req->rq_bytes_sent)
934 return;
935
Chuck Leverff839972010-05-07 13:34:47 -0400936 req->rq_xtime = ktime_get();
Chuck Levera246b012005-08-11 16:25:23 -0400937 status = xprt->ops->send_request(task);
Trond Myklebustc8485e42009-03-11 14:37:59 -0400938 if (status != 0) {
939 task->tk_status = status;
Chuck Leverfe3aca22005-08-25 16:25:50 -0700940 return;
941 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942
Trond Myklebustc8485e42009-03-11 14:37:59 -0400943 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
Bryan Schumaker468f8612011-04-18 15:57:32 -0400944 task->tk_flags |= RPC_TASK_SENT;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400945 spin_lock_bh(&xprt->transport_lock);
946
947 xprt->ops->set_retrans_timeout(task);
948
Andy Adamson15a45202012-02-14 16:19:18 -0500949 numreqs = atomic_read(&xprt->num_reqs);
950 if (numreqs > xprt->stat.max_slots)
951 xprt->stat.max_slots = numreqs;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400952 xprt->stat.sends++;
953 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
954 xprt->stat.bklog_u += xprt->backlog.qlen;
Andy Adamson15a45202012-02-14 16:19:18 -0500955 xprt->stat.sending_u += xprt->sending.qlen;
956 xprt->stat.pending_u += xprt->pending.qlen;
Trond Myklebustc8485e42009-03-11 14:37:59 -0400957
958 /* Don't race with disconnect */
959 if (!xprt_connected(xprt))
960 task->tk_status = -ENOTCONN;
Trond Myklebust0a660522013-09-25 11:31:54 -0400961 else {
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400962 /*
963 * Sleep on the pending queue since
964 * we're expecting a reply.
965 */
Trond Myklebust0a660522013-09-25 11:31:54 -0400966 if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task))
967 rpc_sleep_on(&xprt->pending, task, xprt_timer);
968 req->rq_connect_cookie = xprt->connect_cookie;
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -0400969 }
Trond Myklebustc8485e42009-03-11 14:37:59 -0400970 spin_unlock_bh(&xprt->transport_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971}
972
Trond Myklebustba60eb22013-04-14 10:49:37 -0400973static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
974{
975 set_bit(XPRT_CONGESTED, &xprt->state);
976 rpc_sleep_on(&xprt->backlog, task, NULL);
977}
978
979static void xprt_wake_up_backlog(struct rpc_xprt *xprt)
980{
981 if (rpc_wake_up_next(&xprt->backlog) == NULL)
982 clear_bit(XPRT_CONGESTED, &xprt->state);
983}
984
985static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
986{
987 bool ret = false;
988
989 if (!test_bit(XPRT_CONGESTED, &xprt->state))
990 goto out;
991 spin_lock(&xprt->reserve_lock);
992 if (test_bit(XPRT_CONGESTED, &xprt->state)) {
993 rpc_sleep_on(&xprt->backlog, task, NULL);
994 ret = true;
995 }
996 spin_unlock(&xprt->reserve_lock);
997out:
998 return ret;
999}
1000
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001001static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
1002{
1003 struct rpc_rqst *req = ERR_PTR(-EAGAIN);
1004
1005 if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))
1006 goto out;
1007 req = kzalloc(sizeof(struct rpc_rqst), gfp_flags);
1008 if (req != NULL)
1009 goto out;
1010 atomic_dec(&xprt->num_reqs);
1011 req = ERR_PTR(-ENOMEM);
1012out:
1013 return req;
1014}
1015
1016static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1017{
1018 if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {
1019 kfree(req);
1020 return true;
1021 }
1022 return false;
1023}
1024
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001025void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026{
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001027 struct rpc_rqst *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001029 spin_lock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 if (!list_empty(&xprt->free)) {
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001031 req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1032 list_del(&req->rq_list);
1033 goto out_init_req;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 }
Jeff Layton6b343092012-05-16 13:30:35 -04001035 req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001036 if (!IS_ERR(req))
1037 goto out_init_req;
1038 switch (PTR_ERR(req)) {
1039 case -ENOMEM:
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001040 dprintk("RPC: dynamic allocation of request slot "
1041 "failed! Retrying\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001042 task->tk_status = -ENOMEM;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001043 break;
1044 case -EAGAIN:
Trond Myklebustba60eb22013-04-14 10:49:37 -04001045 xprt_add_backlog(xprt, task);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001046 dprintk("RPC: waiting for request slot\n");
Trond Myklebust1afeaf52012-05-19 12:12:53 -04001047 default:
1048 task->tk_status = -EAGAIN;
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001049 }
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001050 spin_unlock(&xprt->reserve_lock);
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001051 return;
1052out_init_req:
1053 task->tk_status = 0;
1054 task->tk_rqstp = req;
1055 xprt_request_init(task, xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001056 spin_unlock(&xprt->reserve_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057}
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001058EXPORT_SYMBOL_GPL(xprt_alloc_slot);
1059
1060void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
1061{
1062 /* Note: grabbing the xprt_lock_write() ensures that we throttle
1063 * new slot allocation if the transport is congested (i.e. when
1064 * reconnecting a stream transport or when out of socket write
1065 * buffer space).
1066 */
1067 if (xprt_lock_write(xprt, task)) {
1068 xprt_alloc_slot(xprt, task);
1069 xprt_release_write(xprt, task);
1070 }
1071}
1072EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001074static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1075{
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001076 spin_lock(&xprt->reserve_lock);
Trond Myklebustc25573b2011-12-01 14:16:17 -05001077 if (!xprt_dynamic_free_slot(xprt, req)) {
1078 memset(req, 0, sizeof(*req)); /* mark unused */
1079 list_add(&req->rq_list, &xprt->free);
1080 }
Trond Myklebustba60eb22013-04-14 10:49:37 -04001081 xprt_wake_up_backlog(xprt);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001082 spin_unlock(&xprt->reserve_lock);
1083}
1084
Trond Myklebust21de0a92011-07-17 16:57:32 -04001085static void xprt_free_all_slots(struct rpc_xprt *xprt)
1086{
1087 struct rpc_rqst *req;
1088 while (!list_empty(&xprt->free)) {
1089 req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list);
1090 list_del(&req->rq_list);
1091 kfree(req);
1092 }
1093}
1094
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001095struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
1096 unsigned int num_prealloc,
1097 unsigned int max_alloc)
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001098{
1099 struct rpc_xprt *xprt;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001100 struct rpc_rqst *req;
1101 int i;
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001102
1103 xprt = kzalloc(size, GFP_KERNEL);
1104 if (xprt == NULL)
1105 goto out;
1106
Trond Myklebust21de0a92011-07-17 16:57:32 -04001107 xprt_init(xprt, net);
1108
1109 for (i = 0; i < num_prealloc; i++) {
1110 req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
1111 if (!req)
wangweidong83131642013-10-15 11:44:30 +08001112 goto out_free;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001113 list_add(&req->rq_list, &xprt->free);
1114 }
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001115 if (max_alloc > num_prealloc)
1116 xprt->max_reqs = max_alloc;
1117 else
1118 xprt->max_reqs = num_prealloc;
1119 xprt->min_reqs = num_prealloc;
1120 atomic_set(&xprt->num_reqs, num_prealloc);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001121
1122 return xprt;
1123
1124out_free:
Trond Myklebust21de0a92011-07-17 16:57:32 -04001125 xprt_free(xprt);
Pavel Emelyanovbd1722d2010-09-29 16:02:43 +04001126out:
1127 return NULL;
1128}
1129EXPORT_SYMBOL_GPL(xprt_alloc);
1130
Pavel Emelyanove204e622010-09-29 16:03:13 +04001131void xprt_free(struct rpc_xprt *xprt)
1132{
Pavel Emelyanov37aa2132010-09-29 16:05:43 +04001133 put_net(xprt->xprt_net);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001134 xprt_free_all_slots(xprt);
Pavel Emelyanove204e622010-09-29 16:03:13 +04001135 kfree(xprt);
1136}
1137EXPORT_SYMBOL_GPL(xprt_free);
1138
Chuck Lever9903cd12005-08-11 16:25:26 -04001139/**
1140 * xprt_reserve - allocate an RPC request slot
1141 * @task: RPC task requesting a slot allocation
1142 *
Trond Myklebustba60eb22013-04-14 10:49:37 -04001143 * If the transport is marked as being congested, or if no more
1144 * slots are available, place the task on the transport's
Chuck Lever9903cd12005-08-11 16:25:26 -04001145 * backlog queue.
1146 */
1147void xprt_reserve(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148{
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001149 struct rpc_xprt *xprt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001151 task->tk_status = 0;
1152 if (task->tk_rqstp != NULL)
1153 return;
1154
Trond Myklebust43cedbf0e2011-07-17 16:01:03 -04001155 task->tk_timeout = 0;
1156 task->tk_status = -EAGAIN;
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001157 rcu_read_lock();
1158 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustba60eb22013-04-14 10:49:37 -04001159 if (!xprt_throttle_congested(xprt, task))
1160 xprt->ops->alloc_slot(xprt, task);
1161 rcu_read_unlock();
1162}
1163
1164/**
1165 * xprt_retry_reserve - allocate an RPC request slot
1166 * @task: RPC task requesting a slot allocation
1167 *
1168 * If no more slots are available, place the task on the transport's
1169 * backlog queue.
1170 * Note that the only difference with xprt_reserve is that we now
1171 * ignore the value of the XPRT_CONGESTED flag.
1172 */
1173void xprt_retry_reserve(struct rpc_task *task)
1174{
1175 struct rpc_xprt *xprt;
1176
1177 task->tk_status = 0;
1178 if (task->tk_rqstp != NULL)
1179 return;
1180
1181 task->tk_timeout = 0;
1182 task->tk_status = -EAGAIN;
1183 rcu_read_lock();
1184 xprt = rcu_dereference(task->tk_client->cl_xprt);
Trond Myklebustf39c1bf2012-09-07 11:08:50 -04001185 xprt->ops->alloc_slot(xprt, task);
Trond Myklebust45bc0dc2013-01-08 10:03:22 -05001186 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187}
1188
Alexey Dobriyand8ed0292006-09-26 22:29:38 -07001189static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190{
Eric Dumazet0eae88f2010-04-20 19:06:52 -07001191 return (__force __be32)xprt->xid++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192}
1193
1194static inline void xprt_init_xid(struct rpc_xprt *xprt)
1195{
Aruna-Hewapathirane63862b52014-01-11 07:15:59 -05001196 xprt->xid = prandom_u32();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197}
1198
Chuck Lever9903cd12005-08-11 16:25:26 -04001199static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200{
1201 struct rpc_rqst *req = task->tk_rqstp;
1202
Trond Myklebustd9ba1312011-07-17 18:11:30 -04001203 INIT_LIST_HEAD(&req->rq_list);
Trond Myklebustba7392b2007-12-20 16:03:55 -05001204 req->rq_timeout = task->tk_client->cl_timeout->to_initval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 req->rq_task = task;
1206 req->rq_xprt = xprt;
Chuck Lever02107142006-01-03 09:55:49 +01001207 req->rq_buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 req->rq_xid = xprt_alloc_xid(xprt);
Trond Myklebust0a660522013-09-25 11:31:54 -04001209 req->rq_connect_cookie = xprt->connect_cookie - 1;
Trond Myklebust92551942013-09-27 11:28:40 -04001210 req->rq_bytes_sent = 0;
1211 req->rq_snd_buf.len = 0;
1212 req->rq_snd_buf.buflen = 0;
1213 req->rq_rcv_buf.len = 0;
1214 req->rq_rcv_buf.buflen = 0;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001215 req->rq_release_snd_buf = NULL;
Trond Myklebustda458282006-08-31 15:44:52 -04001216 xprt_reset_majortimeo(req);
Chuck Lever46121cf2007-01-31 12:14:08 -05001217 dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 req, ntohl(req->rq_xid));
1219}
1220
Chuck Lever9903cd12005-08-11 16:25:26 -04001221/**
1222 * xprt_release - release an RPC request slot
1223 * @task: task which is finished with the slot
1224 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 */
Chuck Lever9903cd12005-08-11 16:25:26 -04001226void xprt_release(struct rpc_task *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227{
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001228 struct rpc_xprt *xprt;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001229 struct rpc_rqst *req = task->tk_rqstp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
Trond Myklebust87ed5002013-01-07 14:30:46 -05001231 if (req == NULL) {
1232 if (task->tk_client) {
1233 rcu_read_lock();
1234 xprt = rcu_dereference(task->tk_client->cl_xprt);
1235 if (xprt->snd_task == task)
1236 xprt_release_write(xprt, task);
1237 rcu_read_unlock();
1238 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 return;
Trond Myklebust87ed5002013-01-07 14:30:46 -05001240 }
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001241
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001242 xprt = req->rq_xprt;
Weston Andros Adamson0a702192012-02-17 13:15:24 -05001243 if (task->tk_ops->rpc_count_stats != NULL)
1244 task->tk_ops->rpc_count_stats(task, task->tk_calldata);
1245 else if (task->tk_client)
1246 rpc_count_iostats(task, task->tk_client->cl_metrics);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001247 spin_lock_bh(&xprt->transport_lock);
Chuck Lever49e9a892005-08-25 16:25:51 -07001248 xprt->ops->release_xprt(xprt, task);
Chuck Levera58dd392005-08-25 16:25:53 -07001249 if (xprt->ops->release_request)
1250 xprt->ops->release_request(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 if (!list_empty(&req->rq_list))
1252 list_del(&req->rq_list);
1253 xprt->last_used = jiffies;
Rahul Iyer4cfc7e62009-09-10 17:32:28 +03001254 if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
Chuck Levera246b012005-08-11 16:25:23 -04001255 mod_timer(&xprt->timer,
Chuck Lever03bf4b72005-08-25 16:25:55 -07001256 xprt->last_used + xprt->idle_timeout);
Chuck Lever4a0f8c02005-08-11 16:25:32 -04001257 spin_unlock_bh(&xprt->transport_lock);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001258 if (req->rq_buffer)
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001259 xprt->ops->buf_free(req->rq_buffer);
Trond Myklebusta17c2152010-07-31 14:29:08 -04001260 if (req->rq_cred != NULL)
1261 put_rpccred(req->rq_cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 task->tk_rqstp = NULL;
J. Bruce Fieldsead5e1c2005-10-13 16:54:43 -04001263 if (req->rq_release_snd_buf)
1264 req->rq_release_snd_buf(req);
Ricardo Labiaga55ae1aa2009-04-01 09:23:03 -04001265
Chuck Lever46121cf2007-01-31 12:14:08 -05001266 dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
Trond Myklebustee5ebe82010-04-16 16:37:01 -04001267 if (likely(!bc_prealloc(req)))
1268 xprt_free_slot(xprt, req);
1269 else
Trond Myklebustc9acb422010-03-19 15:36:22 -04001270 xprt_free_bc_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271}
1272
Trond Myklebust21de0a92011-07-17 16:57:32 -04001273static void xprt_init(struct rpc_xprt *xprt, struct net *net)
Chuck Leverc2866762006-08-22 20:06:20 -04001274{
Trond Myklebust21de0a92011-07-17 16:57:32 -04001275 atomic_set(&xprt->count, 1);
Chuck Leverc2866762006-08-22 20:06:20 -04001276
1277 spin_lock_init(&xprt->transport_lock);
1278 spin_lock_init(&xprt->reserve_lock);
1279
1280 INIT_LIST_HEAD(&xprt->free);
1281 INIT_LIST_HEAD(&xprt->recv);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001282#if defined(CONFIG_SUNRPC_BACKCHANNEL)
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001283 spin_lock_init(&xprt->bc_pa_lock);
1284 INIT_LIST_HEAD(&xprt->bc_pa_list);
Trond Myklebust9e00abc2011-07-13 19:20:49 -04001285#endif /* CONFIG_SUNRPC_BACKCHANNEL */
Ricardo Labiagaf9acac12009-04-01 09:22:59 -04001286
Chuck Leverc2866762006-08-22 20:06:20 -04001287 xprt->last_used = jiffies;
1288 xprt->cwnd = RPC_INITCWND;
Chuck Levera5090502007-03-29 16:48:04 -04001289 xprt->bind_index = 0;
Chuck Leverc2866762006-08-22 20:06:20 -04001290
1291 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
1292 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
Trond Myklebust34006ce2011-07-17 18:11:34 -04001293 rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending");
Chuck Leverc2866762006-08-22 20:06:20 -04001294 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1295
Chuck Leverc2866762006-08-22 20:06:20 -04001296 xprt_init_xid(xprt);
1297
Trond Myklebust21de0a92011-07-17 16:57:32 -04001298 xprt->xprt_net = get_net(net);
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001299}
1300
1301/**
1302 * xprt_create_transport - create an RPC transport
1303 * @args: rpc transport creation arguments
1304 *
1305 */
1306struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
1307{
1308 struct rpc_xprt *xprt;
1309 struct xprt_class *t;
1310
1311 spin_lock(&xprt_list_lock);
1312 list_for_each_entry(t, &xprt_list, list) {
1313 if (t->ident == args->ident) {
1314 spin_unlock(&xprt_list_lock);
1315 goto found;
1316 }
1317 }
1318 spin_unlock(&xprt_list_lock);
1319 printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
1320 return ERR_PTR(-EIO);
1321
1322found:
1323 xprt = t->setup(args);
1324 if (IS_ERR(xprt)) {
1325 dprintk("RPC: xprt_create_transport: failed, %ld\n",
1326 -PTR_ERR(xprt));
Trond Myklebust21de0a92011-07-17 16:57:32 -04001327 goto out;
Trond Myklebust8d9266f2011-07-17 16:01:09 -04001328 }
J. Bruce Fields33d90ac2013-04-11 15:06:36 -04001329 if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
1330 xprt->idle_timeout = 0;
Trond Myklebust21de0a92011-07-17 16:57:32 -04001331 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
1332 if (xprt_has_timer(xprt))
1333 setup_timer(&xprt->timer, xprt_init_autodisconnect,
1334 (unsigned long)xprt);
1335 else
1336 init_timer(&xprt->timer);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001337
1338 if (strlen(args->servername) > RPC_MAXNETNAMELEN) {
1339 xprt_destroy(xprt);
1340 return ERR_PTR(-EINVAL);
1341 }
1342 xprt->servername = kstrdup(args->servername, GFP_KERNEL);
1343 if (xprt->servername == NULL) {
1344 xprt_destroy(xprt);
1345 return ERR_PTR(-ENOMEM);
1346 }
1347
Chuck Lever46121cf2007-01-31 12:14:08 -05001348 dprintk("RPC: created transport %p with %u slots\n", xprt,
Chuck Leverc2866762006-08-22 20:06:20 -04001349 xprt->max_reqs);
Trond Myklebust21de0a92011-07-17 16:57:32 -04001350out:
Chuck Leverc2866762006-08-22 20:06:20 -04001351 return xprt;
1352}
1353
Chuck Lever9903cd12005-08-11 16:25:26 -04001354/**
1355 * xprt_destroy - destroy an RPC transport, killing off all requests.
Trond Myklebusta8de2402011-03-15 19:56:30 -04001356 * @xprt: transport to destroy
Chuck Lever9903cd12005-08-11 16:25:26 -04001357 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358 */
Trond Myklebusta8de2402011-03-15 19:56:30 -04001359static void xprt_destroy(struct rpc_xprt *xprt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360{
Chuck Lever46121cf2007-01-31 12:14:08 -05001361 dprintk("RPC: destroying transport %p\n", xprt);
Trond Myklebust0065db32006-01-03 09:55:56 +01001362 del_timer_sync(&xprt->timer);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001363
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001364 rpc_destroy_wait_queue(&xprt->binding);
1365 rpc_destroy_wait_queue(&xprt->pending);
1366 rpc_destroy_wait_queue(&xprt->sending);
Trond Myklebustf6a1cc82008-02-22 17:06:55 -05001367 rpc_destroy_wait_queue(&xprt->backlog);
J. Bruce Fieldsc3ae62ae2010-08-03 17:22:20 -04001368 cancel_work_sync(&xprt->task_cleanup);
Trond Myklebust4e0038b2012-03-01 17:01:05 -05001369 kfree(xprt->servername);
Chuck Leverc8541ec2006-10-17 14:44:27 -04001370 /*
1371 * Tear down transport state and free the rpc_xprt
1372 */
Chuck Levera246b012005-08-11 16:25:23 -04001373 xprt->ops->destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001374}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001376/**
1377 * xprt_put - release a reference to an RPC transport.
1378 * @xprt: pointer to the transport
1379 *
1380 */
1381void xprt_put(struct rpc_xprt *xprt)
1382{
Trond Myklebusta8de2402011-03-15 19:56:30 -04001383 if (atomic_dec_and_test(&xprt->count))
1384 xprt_destroy(xprt);
Trond Myklebust6b6ca862006-09-05 12:55:57 -04001385}