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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | |
55aa4f58 CL |
13 | * the request struct, and calls xprt_transmit(). |
14 | * - xprt_transmit sends the message and installs the caller on the | |
55ae1aab RL |
15 | * 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. | |
1da177e4 | 18 | * - When a packet arrives, the data_ready handler walks the list of |
55aa4f58 | 19 | * pending requests for that transport. If a matching XID is found, the |
1da177e4 LT |
20 | * 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> | |
55aa4f58 CL |
36 | * |
37 | * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> | |
1da177e4 LT |
38 | */ |
39 | ||
a246b010 CL |
40 | #include <linux/module.h> |
41 | ||
1da177e4 | 42 | #include <linux/types.h> |
a246b010 | 43 | #include <linux/interrupt.h> |
1da177e4 | 44 | #include <linux/workqueue.h> |
bf3fcf89 | 45 | #include <linux/net.h> |
ff839970 | 46 | #include <linux/ktime.h> |
1da177e4 | 47 | |
a246b010 | 48 | #include <linux/sunrpc/clnt.h> |
11c556b3 | 49 | #include <linux/sunrpc/metrics.h> |
c9acb42e | 50 | #include <linux/sunrpc/bc_xprt.h> |
1da177e4 | 51 | |
55ae1aab RL |
52 | #include "sunrpc.h" |
53 | ||
1da177e4 LT |
54 | /* |
55 | * Local variables | |
56 | */ | |
57 | ||
58 | #ifdef RPC_DEBUG | |
1da177e4 LT |
59 | # define RPCDBG_FACILITY RPCDBG_XPRT |
60 | #endif | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * Local functions | |
64 | */ | |
21de0a95 | 65 | static void xprt_init(struct rpc_xprt *xprt, struct net *net); |
1da177e4 | 66 | static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); |
1da177e4 | 67 | static void xprt_connect_status(struct rpc_task *task); |
1da177e4 | 68 | static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); |
4e0038b6 | 69 | static void xprt_destroy(struct rpc_xprt *xprt); |
1da177e4 | 70 | |
5ba03e82 | 71 | static DEFINE_SPINLOCK(xprt_list_lock); |
81c098af TT |
72 | static LIST_HEAD(xprt_list); |
73 | ||
555ee3af CL |
74 | /* |
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) | |
1da177e4 | 91 | |
81c098af TT |
92 | /** |
93 | * 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 | */ | |
104 | int 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 */ | |
4fa016eb | 113 | if (t->ident == transport->ident) |
81c098af TT |
114 | goto out; |
115 | } | |
116 | ||
c9f6cde6 DL |
117 | list_add_tail(&transport->list, &xprt_list); |
118 | printk(KERN_INFO "RPC: Registered %s transport module.\n", | |
119 | transport->name); | |
120 | result = 0; | |
81c098af TT |
121 | |
122 | out: | |
123 | spin_unlock(&xprt_list_lock); | |
124 | return result; | |
125 | } | |
126 | EXPORT_SYMBOL_GPL(xprt_register_transport); | |
127 | ||
128 | /** | |
129 | * xprt_unregister_transport - unregister a transport implementation | |
65b6e42c | 130 | * @transport: transport to unregister |
81c098af TT |
131 | * |
132 | * Returns: | |
133 | * 0: transport successfully unregistered | |
134 | * -ENOENT: transport never registered | |
135 | */ | |
136 | int 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); | |
81c098af TT |
149 | goto out; |
150 | } | |
151 | } | |
152 | result = -ENOENT; | |
153 | ||
154 | out: | |
155 | spin_unlock(&xprt_list_lock); | |
156 | return result; | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(xprt_unregister_transport); | |
159 | ||
441e3e24 TT |
160 | /** |
161 | * 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 | */ | |
168 | int xprt_load_transport(const char *transport_name) | |
169 | { | |
170 | struct xprt_class *t; | |
441e3e24 TT |
171 | 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); | |
ef7ffe8f | 182 | result = request_module("xprt%s", transport_name); |
441e3e24 TT |
183 | out: |
184 | return result; | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(xprt_load_transport); | |
187 | ||
12a80469 CL |
188 | /** |
189 | * xprt_reserve_xprt - serialize write access to transports | |
190 | * @task: task that is requesting access to the transport | |
177c27bf | 191 | * @xprt: pointer to the target transport |
12a80469 CL |
192 | * |
193 | * This prevents mixing the payload of separate requests, and prevents | |
194 | * transport connects from colliding with writes. No congestion control | |
195 | * is provided. | |
196 | */ | |
43cedbf0 | 197 | int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
12a80469 | 198 | { |
12a80469 | 199 | struct rpc_rqst *req = task->tk_rqstp; |
34006cee | 200 | int priority; |
12a80469 CL |
201 | |
202 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { | |
203 | if (task == xprt->snd_task) | |
204 | return 1; | |
12a80469 CL |
205 | goto out_sleep; |
206 | } | |
207 | xprt->snd_task = task; | |
43cedbf0 TM |
208 | if (req != NULL) { |
209 | req->rq_bytes_sent = 0; | |
210 | req->rq_ntrans++; | |
211 | } | |
4d4a76f3 | 212 | |
12a80469 CL |
213 | return 1; |
214 | ||
215 | out_sleep: | |
46121cf7 | 216 | dprintk("RPC: %5u failed to lock transport %p\n", |
12a80469 CL |
217 | task->tk_pid, xprt); |
218 | task->tk_timeout = 0; | |
219 | task->tk_status = -EAGAIN; | |
34006cee TM |
220 | if (req == NULL) |
221 | priority = RPC_PRIORITY_LOW; | |
222 | else if (!req->rq_ntrans) | |
223 | priority = RPC_PRIORITY_NORMAL; | |
12a80469 | 224 | else |
34006cee TM |
225 | priority = RPC_PRIORITY_HIGH; |
226 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
12a80469 CL |
227 | return 0; |
228 | } | |
12444809 | 229 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
12a80469 | 230 | |
632e3bdc TM |
231 | static void xprt_clear_locked(struct rpc_xprt *xprt) |
232 | { | |
233 | xprt->snd_task = NULL; | |
234 | if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) { | |
235 | smp_mb__before_clear_bit(); | |
236 | clear_bit(XPRT_LOCKED, &xprt->state); | |
237 | smp_mb__after_clear_bit(); | |
238 | } else | |
c1384c9c | 239 | queue_work(rpciod_workqueue, &xprt->task_cleanup); |
632e3bdc TM |
240 | } |
241 | ||
1da177e4 | 242 | /* |
12a80469 CL |
243 | * xprt_reserve_xprt_cong - serialize write access to transports |
244 | * @task: task that is requesting access to the transport | |
245 | * | |
246 | * Same as xprt_reserve_xprt, but Van Jacobson congestion control is | |
247 | * integrated into the decision of whether a request is allowed to be | |
248 | * woken up and given access to the transport. | |
1da177e4 | 249 | */ |
43cedbf0 | 250 | int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
251 | { |
252 | struct rpc_rqst *req = task->tk_rqstp; | |
34006cee | 253 | int priority; |
1da177e4 | 254 | |
2226feb6 | 255 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
1da177e4 LT |
256 | if (task == xprt->snd_task) |
257 | return 1; | |
1da177e4 LT |
258 | goto out_sleep; |
259 | } | |
43cedbf0 TM |
260 | if (req == NULL) { |
261 | xprt->snd_task = task; | |
262 | return 1; | |
263 | } | |
12a80469 | 264 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 265 | xprt->snd_task = task; |
43cedbf0 TM |
266 | req->rq_bytes_sent = 0; |
267 | req->rq_ntrans++; | |
1da177e4 LT |
268 | return 1; |
269 | } | |
632e3bdc | 270 | xprt_clear_locked(xprt); |
1da177e4 | 271 | out_sleep: |
46121cf7 | 272 | dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); |
1da177e4 LT |
273 | task->tk_timeout = 0; |
274 | task->tk_status = -EAGAIN; | |
34006cee TM |
275 | if (req == NULL) |
276 | priority = RPC_PRIORITY_LOW; | |
277 | else if (!req->rq_ntrans) | |
278 | priority = RPC_PRIORITY_NORMAL; | |
1da177e4 | 279 | else |
34006cee TM |
280 | priority = RPC_PRIORITY_HIGH; |
281 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
1da177e4 LT |
282 | return 0; |
283 | } | |
12444809 | 284 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
1da177e4 | 285 | |
12a80469 | 286 | static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
287 | { |
288 | int retval; | |
289 | ||
4a0f8c04 | 290 | spin_lock_bh(&xprt->transport_lock); |
43cedbf0 | 291 | retval = xprt->ops->reserve_xprt(xprt, task); |
4a0f8c04 | 292 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
293 | return retval; |
294 | } | |
295 | ||
961a828d | 296 | static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
49e9a890 | 297 | { |
961a828d | 298 | struct rpc_xprt *xprt = data; |
49e9a890 CL |
299 | struct rpc_rqst *req; |
300 | ||
49e9a890 CL |
301 | req = task->tk_rqstp; |
302 | xprt->snd_task = task; | |
303 | if (req) { | |
304 | req->rq_bytes_sent = 0; | |
305 | req->rq_ntrans++; | |
306 | } | |
961a828d TM |
307 | return true; |
308 | } | |
49e9a890 | 309 | |
961a828d TM |
310 | static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
311 | { | |
312 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
313 | return; | |
314 | ||
315 | if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt)) | |
316 | return; | |
632e3bdc | 317 | xprt_clear_locked(xprt); |
49e9a890 CL |
318 | } |
319 | ||
961a828d | 320 | static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data) |
1da177e4 | 321 | { |
961a828d | 322 | struct rpc_xprt *xprt = data; |
43cedbf0 | 323 | struct rpc_rqst *req; |
1da177e4 | 324 | |
43cedbf0 TM |
325 | req = task->tk_rqstp; |
326 | if (req == NULL) { | |
327 | xprt->snd_task = task; | |
961a828d | 328 | return true; |
43cedbf0 | 329 | } |
49e9a890 | 330 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 331 | xprt->snd_task = task; |
43cedbf0 TM |
332 | req->rq_bytes_sent = 0; |
333 | req->rq_ntrans++; | |
961a828d | 334 | return true; |
1da177e4 | 335 | } |
961a828d TM |
336 | return false; |
337 | } | |
338 | ||
339 | static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) | |
340 | { | |
341 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
342 | return; | |
343 | if (RPCXPRT_CONGESTED(xprt)) | |
344 | goto out_unlock; | |
345 | if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt)) | |
346 | return; | |
1da177e4 | 347 | out_unlock: |
632e3bdc | 348 | xprt_clear_locked(xprt); |
1da177e4 LT |
349 | } |
350 | ||
49e9a890 CL |
351 | /** |
352 | * xprt_release_xprt - allow other requests to use a transport | |
353 | * @xprt: transport with other tasks potentially waiting | |
354 | * @task: task that is releasing access to the transport | |
355 | * | |
356 | * Note that "task" can be NULL. No congestion control is provided. | |
1da177e4 | 357 | */ |
49e9a890 | 358 | void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
359 | { |
360 | if (xprt->snd_task == task) { | |
632e3bdc | 361 | xprt_clear_locked(xprt); |
1da177e4 LT |
362 | __xprt_lock_write_next(xprt); |
363 | } | |
364 | } | |
12444809 | 365 | EXPORT_SYMBOL_GPL(xprt_release_xprt); |
1da177e4 | 366 | |
49e9a890 CL |
367 | /** |
368 | * xprt_release_xprt_cong - allow other requests to use a transport | |
369 | * @xprt: transport with other tasks potentially waiting | |
370 | * @task: task that is releasing access to the transport | |
371 | * | |
372 | * Note that "task" can be NULL. Another task is awoken to use the | |
373 | * transport if the transport's congestion window allows it. | |
374 | */ | |
375 | void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
376 | { | |
377 | if (xprt->snd_task == task) { | |
632e3bdc | 378 | xprt_clear_locked(xprt); |
49e9a890 CL |
379 | __xprt_lock_write_next_cong(xprt); |
380 | } | |
381 | } | |
12444809 | 382 | EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
49e9a890 CL |
383 | |
384 | static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
1da177e4 | 385 | { |
4a0f8c04 | 386 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 387 | xprt->ops->release_xprt(xprt, task); |
4a0f8c04 | 388 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
389 | } |
390 | ||
1da177e4 LT |
391 | /* |
392 | * Van Jacobson congestion avoidance. Check if the congestion window | |
393 | * overflowed. Put the task to sleep if this is the case. | |
394 | */ | |
395 | static int | |
396 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
397 | { | |
398 | struct rpc_rqst *req = task->tk_rqstp; | |
399 | ||
400 | if (req->rq_cong) | |
401 | return 1; | |
46121cf7 | 402 | dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", |
1da177e4 LT |
403 | task->tk_pid, xprt->cong, xprt->cwnd); |
404 | if (RPCXPRT_CONGESTED(xprt)) | |
405 | return 0; | |
406 | req->rq_cong = 1; | |
407 | xprt->cong += RPC_CWNDSCALE; | |
408 | return 1; | |
409 | } | |
410 | ||
411 | /* | |
412 | * Adjust the congestion window, and wake up the next task | |
413 | * that has been sleeping due to congestion | |
414 | */ | |
415 | static void | |
416 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
417 | { | |
418 | if (!req->rq_cong) | |
419 | return; | |
420 | req->rq_cong = 0; | |
421 | xprt->cong -= RPC_CWNDSCALE; | |
49e9a890 | 422 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
423 | } |
424 | ||
a58dd398 CL |
425 | /** |
426 | * xprt_release_rqst_cong - housekeeping when request is complete | |
427 | * @task: RPC request that recently completed | |
428 | * | |
429 | * Useful for transports that require congestion control. | |
430 | */ | |
431 | void xprt_release_rqst_cong(struct rpc_task *task) | |
432 | { | |
433 | __xprt_put_cong(task->tk_xprt, task->tk_rqstp); | |
434 | } | |
12444809 | 435 | EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
a58dd398 | 436 | |
46c0ee8b CL |
437 | /** |
438 | * xprt_adjust_cwnd - adjust transport congestion window | |
439 | * @task: recently completed RPC request used to adjust window | |
440 | * @result: result code of completed RPC request | |
441 | * | |
1da177e4 LT |
442 | * We use a time-smoothed congestion estimator to avoid heavy oscillation. |
443 | */ | |
46c0ee8b | 444 | void xprt_adjust_cwnd(struct rpc_task *task, int result) |
1da177e4 | 445 | { |
46c0ee8b CL |
446 | struct rpc_rqst *req = task->tk_rqstp; |
447 | struct rpc_xprt *xprt = task->tk_xprt; | |
448 | unsigned long cwnd = xprt->cwnd; | |
1da177e4 | 449 | |
1da177e4 LT |
450 | if (result >= 0 && cwnd <= xprt->cong) { |
451 | /* The (cwnd >> 1) term makes sure | |
452 | * the result gets rounded properly. */ | |
453 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; | |
454 | if (cwnd > RPC_MAXCWND(xprt)) | |
455 | cwnd = RPC_MAXCWND(xprt); | |
49e9a890 | 456 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
457 | } else if (result == -ETIMEDOUT) { |
458 | cwnd >>= 1; | |
459 | if (cwnd < RPC_CWNDSCALE) | |
460 | cwnd = RPC_CWNDSCALE; | |
461 | } | |
46121cf7 | 462 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", |
1da177e4 LT |
463 | xprt->cong, xprt->cwnd, cwnd); |
464 | xprt->cwnd = cwnd; | |
46c0ee8b | 465 | __xprt_put_cong(xprt, req); |
1da177e4 | 466 | } |
12444809 | 467 | EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
1da177e4 | 468 | |
44fbac22 CL |
469 | /** |
470 | * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue | |
471 | * @xprt: transport with waiting tasks | |
472 | * @status: result code to plant in each task before waking it | |
473 | * | |
474 | */ | |
475 | void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) | |
476 | { | |
477 | if (status < 0) | |
478 | rpc_wake_up_status(&xprt->pending, status); | |
479 | else | |
480 | rpc_wake_up(&xprt->pending); | |
481 | } | |
12444809 | 482 | EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
44fbac22 | 483 | |
c7b2cae8 CL |
484 | /** |
485 | * xprt_wait_for_buffer_space - wait for transport output buffer to clear | |
486 | * @task: task to be put to sleep | |
0b80ae42 | 487 | * @action: function pointer to be executed after wait |
c7b2cae8 | 488 | */ |
b6ddf64f | 489 | void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) |
c7b2cae8 CL |
490 | { |
491 | struct rpc_rqst *req = task->tk_rqstp; | |
492 | struct rpc_xprt *xprt = req->rq_xprt; | |
493 | ||
494 | task->tk_timeout = req->rq_timeout; | |
b6ddf64f | 495 | rpc_sleep_on(&xprt->pending, task, action); |
c7b2cae8 | 496 | } |
12444809 | 497 | EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
c7b2cae8 CL |
498 | |
499 | /** | |
500 | * xprt_write_space - wake the task waiting for transport output buffer space | |
501 | * @xprt: transport with waiting tasks | |
502 | * | |
503 | * Can be called in a soft IRQ context, so xprt_write_space never sleeps. | |
504 | */ | |
505 | void xprt_write_space(struct rpc_xprt *xprt) | |
506 | { | |
507 | if (unlikely(xprt->shutdown)) | |
508 | return; | |
509 | ||
510 | spin_lock_bh(&xprt->transport_lock); | |
511 | if (xprt->snd_task) { | |
46121cf7 CL |
512 | dprintk("RPC: write space: waking waiting task on " |
513 | "xprt %p\n", xprt); | |
fda13939 | 514 | rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); |
c7b2cae8 CL |
515 | } |
516 | spin_unlock_bh(&xprt->transport_lock); | |
517 | } | |
12444809 | 518 | EXPORT_SYMBOL_GPL(xprt_write_space); |
c7b2cae8 | 519 | |
fe3aca29 CL |
520 | /** |
521 | * xprt_set_retrans_timeout_def - set a request's retransmit timeout | |
522 | * @task: task whose timeout is to be set | |
523 | * | |
524 | * Set a request's retransmit timeout based on the transport's | |
525 | * default timeout parameters. Used by transports that don't adjust | |
526 | * the retransmit timeout based on round-trip time estimation. | |
527 | */ | |
528 | void xprt_set_retrans_timeout_def(struct rpc_task *task) | |
529 | { | |
530 | task->tk_timeout = task->tk_rqstp->rq_timeout; | |
531 | } | |
12444809 | 532 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); |
fe3aca29 CL |
533 | |
534 | /* | |
535 | * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout | |
536 | * @task: task whose timeout is to be set | |
cca5172a | 537 | * |
fe3aca29 CL |
538 | * Set a request's retransmit timeout using the RTT estimator. |
539 | */ | |
540 | void xprt_set_retrans_timeout_rtt(struct rpc_task *task) | |
541 | { | |
542 | int timer = task->tk_msg.rpc_proc->p_timer; | |
ba7392bb TM |
543 | struct rpc_clnt *clnt = task->tk_client; |
544 | struct rpc_rtt *rtt = clnt->cl_rtt; | |
fe3aca29 | 545 | struct rpc_rqst *req = task->tk_rqstp; |
ba7392bb | 546 | unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
fe3aca29 CL |
547 | |
548 | task->tk_timeout = rpc_calc_rto(rtt, timer); | |
549 | task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; | |
550 | if (task->tk_timeout > max_timeout || task->tk_timeout == 0) | |
551 | task->tk_timeout = max_timeout; | |
552 | } | |
12444809 | 553 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); |
fe3aca29 | 554 | |
1da177e4 LT |
555 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
556 | { | |
ba7392bb | 557 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
558 | |
559 | req->rq_majortimeo = req->rq_timeout; | |
560 | if (to->to_exponential) | |
561 | req->rq_majortimeo <<= to->to_retries; | |
562 | else | |
563 | req->rq_majortimeo += to->to_increment * to->to_retries; | |
564 | if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) | |
565 | req->rq_majortimeo = to->to_maxval; | |
566 | req->rq_majortimeo += jiffies; | |
567 | } | |
568 | ||
9903cd1c CL |
569 | /** |
570 | * xprt_adjust_timeout - adjust timeout values for next retransmit | |
571 | * @req: RPC request containing parameters to use for the adjustment | |
572 | * | |
1da177e4 LT |
573 | */ |
574 | int xprt_adjust_timeout(struct rpc_rqst *req) | |
575 | { | |
576 | struct rpc_xprt *xprt = req->rq_xprt; | |
ba7392bb | 577 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
578 | int status = 0; |
579 | ||
580 | if (time_before(jiffies, req->rq_majortimeo)) { | |
581 | if (to->to_exponential) | |
582 | req->rq_timeout <<= 1; | |
583 | else | |
584 | req->rq_timeout += to->to_increment; | |
585 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) | |
586 | req->rq_timeout = to->to_maxval; | |
587 | req->rq_retries++; | |
1da177e4 LT |
588 | } else { |
589 | req->rq_timeout = to->to_initval; | |
590 | req->rq_retries = 0; | |
591 | xprt_reset_majortimeo(req); | |
592 | /* Reset the RTT counters == "slow start" */ | |
4a0f8c04 | 593 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 594 | rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
4a0f8c04 | 595 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
596 | status = -ETIMEDOUT; |
597 | } | |
598 | ||
599 | if (req->rq_timeout == 0) { | |
600 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); | |
601 | req->rq_timeout = 5 * HZ; | |
602 | } | |
603 | return status; | |
604 | } | |
605 | ||
65f27f38 | 606 | static void xprt_autoclose(struct work_struct *work) |
1da177e4 | 607 | { |
65f27f38 DH |
608 | struct rpc_xprt *xprt = |
609 | container_of(work, struct rpc_xprt, task_cleanup); | |
1da177e4 | 610 | |
a246b010 | 611 | xprt->ops->close(xprt); |
66af1e55 | 612 | clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
1da177e4 LT |
613 | xprt_release_write(xprt, NULL); |
614 | } | |
615 | ||
9903cd1c | 616 | /** |
62da3b24 | 617 | * xprt_disconnect_done - mark a transport as disconnected |
9903cd1c CL |
618 | * @xprt: transport to flag for disconnect |
619 | * | |
1da177e4 | 620 | */ |
62da3b24 | 621 | void xprt_disconnect_done(struct rpc_xprt *xprt) |
1da177e4 | 622 | { |
46121cf7 | 623 | dprintk("RPC: disconnected transport %p\n", xprt); |
4a0f8c04 | 624 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 625 | xprt_clear_connected(xprt); |
2a491991 | 626 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
4a0f8c04 | 627 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 628 | } |
62da3b24 | 629 | EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
1da177e4 | 630 | |
66af1e55 TM |
631 | /** |
632 | * xprt_force_disconnect - force a transport to disconnect | |
633 | * @xprt: transport to disconnect | |
634 | * | |
635 | */ | |
636 | void xprt_force_disconnect(struct rpc_xprt *xprt) | |
637 | { | |
638 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
639 | spin_lock_bh(&xprt->transport_lock); | |
640 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
641 | /* Try to schedule an autoclose RPC call */ | |
642 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
643 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 644 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
66af1e55 TM |
645 | spin_unlock_bh(&xprt->transport_lock); |
646 | } | |
66af1e55 | 647 | |
7c1d71cf TM |
648 | /** |
649 | * xprt_conditional_disconnect - force a transport to disconnect | |
650 | * @xprt: transport to disconnect | |
651 | * @cookie: 'connection cookie' | |
652 | * | |
653 | * This attempts to break the connection if and only if 'cookie' matches | |
654 | * the current transport 'connection cookie'. It ensures that we don't | |
655 | * try to break the connection more than once when we need to retransmit | |
656 | * a batch of RPC requests. | |
657 | * | |
658 | */ | |
659 | void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) | |
660 | { | |
661 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
662 | spin_lock_bh(&xprt->transport_lock); | |
663 | if (cookie != xprt->connect_cookie) | |
664 | goto out; | |
665 | if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) | |
666 | goto out; | |
667 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
668 | /* Try to schedule an autoclose RPC call */ | |
669 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
670 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 671 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
7c1d71cf TM |
672 | out: |
673 | spin_unlock_bh(&xprt->transport_lock); | |
674 | } | |
675 | ||
1da177e4 LT |
676 | static void |
677 | xprt_init_autodisconnect(unsigned long data) | |
678 | { | |
679 | struct rpc_xprt *xprt = (struct rpc_xprt *)data; | |
680 | ||
4a0f8c04 | 681 | spin_lock(&xprt->transport_lock); |
1da177e4 LT |
682 | if (!list_empty(&xprt->recv) || xprt->shutdown) |
683 | goto out_abort; | |
2226feb6 | 684 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
1da177e4 | 685 | goto out_abort; |
4a0f8c04 | 686 | spin_unlock(&xprt->transport_lock); |
f75e6745 TM |
687 | set_bit(XPRT_CONNECTION_CLOSE, &xprt->state); |
688 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
1da177e4 LT |
689 | return; |
690 | out_abort: | |
4a0f8c04 | 691 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
692 | } |
693 | ||
9903cd1c CL |
694 | /** |
695 | * xprt_connect - schedule a transport connect operation | |
696 | * @task: RPC task that is requesting the connect | |
1da177e4 LT |
697 | * |
698 | */ | |
699 | void xprt_connect(struct rpc_task *task) | |
700 | { | |
701 | struct rpc_xprt *xprt = task->tk_xprt; | |
702 | ||
46121cf7 | 703 | dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, |
1da177e4 LT |
704 | xprt, (xprt_connected(xprt) ? "is" : "is not")); |
705 | ||
ec739ef0 | 706 | if (!xprt_bound(xprt)) { |
01d37c42 | 707 | task->tk_status = -EAGAIN; |
1da177e4 LT |
708 | return; |
709 | } | |
710 | if (!xprt_lock_write(xprt, task)) | |
711 | return; | |
feb8ca37 TM |
712 | |
713 | if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) | |
714 | xprt->ops->close(xprt); | |
715 | ||
1da177e4 | 716 | if (xprt_connected(xprt)) |
a246b010 CL |
717 | xprt_release_write(xprt, task); |
718 | else { | |
87e3c055 | 719 | task->tk_rqstp->rq_bytes_sent = 0; |
a8ce4a8f | 720 | task->tk_timeout = task->tk_rqstp->rq_timeout; |
5d00837b | 721 | rpc_sleep_on(&xprt->pending, task, xprt_connect_status); |
0b9e7943 TM |
722 | |
723 | if (test_bit(XPRT_CLOSING, &xprt->state)) | |
724 | return; | |
725 | if (xprt_test_and_set_connecting(xprt)) | |
726 | return; | |
262ca07d | 727 | xprt->stat.connect_start = jiffies; |
a246b010 | 728 | xprt->ops->connect(task); |
1da177e4 | 729 | } |
1da177e4 LT |
730 | } |
731 | ||
9903cd1c | 732 | static void xprt_connect_status(struct rpc_task *task) |
1da177e4 LT |
733 | { |
734 | struct rpc_xprt *xprt = task->tk_xprt; | |
735 | ||
cd983ef8 | 736 | if (task->tk_status == 0) { |
262ca07d CL |
737 | xprt->stat.connect_count++; |
738 | xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; | |
46121cf7 | 739 | dprintk("RPC: %5u xprt_connect_status: connection established\n", |
1da177e4 LT |
740 | task->tk_pid); |
741 | return; | |
742 | } | |
743 | ||
1da177e4 | 744 | switch (task->tk_status) { |
2a491991 TM |
745 | case -EAGAIN: |
746 | dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); | |
23475d66 | 747 | break; |
1da177e4 | 748 | case -ETIMEDOUT: |
46121cf7 CL |
749 | dprintk("RPC: %5u xprt_connect_status: connect attempt timed " |
750 | "out\n", task->tk_pid); | |
1da177e4 LT |
751 | break; |
752 | default: | |
46121cf7 CL |
753 | dprintk("RPC: %5u xprt_connect_status: error %d connecting to " |
754 | "server %s\n", task->tk_pid, -task->tk_status, | |
4e0038b6 | 755 | xprt->servername); |
23475d66 CL |
756 | xprt_release_write(xprt, task); |
757 | task->tk_status = -EIO; | |
1da177e4 | 758 | } |
1da177e4 LT |
759 | } |
760 | ||
9903cd1c CL |
761 | /** |
762 | * xprt_lookup_rqst - find an RPC request corresponding to an XID | |
763 | * @xprt: transport on which the original request was transmitted | |
764 | * @xid: RPC XID of incoming reply | |
765 | * | |
1da177e4 | 766 | */ |
d8ed029d | 767 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
1da177e4 | 768 | { |
8f3a6de3 | 769 | struct rpc_rqst *entry; |
1da177e4 | 770 | |
8f3a6de3 | 771 | list_for_each_entry(entry, &xprt->recv, rq_list) |
262ca07d CL |
772 | if (entry->rq_xid == xid) |
773 | return entry; | |
46121cf7 CL |
774 | |
775 | dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", | |
776 | ntohl(xid)); | |
262ca07d CL |
777 | xprt->stat.bad_xids++; |
778 | return NULL; | |
1da177e4 | 779 | } |
12444809 | 780 | EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
1da177e4 | 781 | |
bbc72cea | 782 | static void xprt_update_rtt(struct rpc_task *task) |
1570c1e4 CL |
783 | { |
784 | struct rpc_rqst *req = task->tk_rqstp; | |
785 | struct rpc_rtt *rtt = task->tk_client->cl_rtt; | |
786 | unsigned timer = task->tk_msg.rpc_proc->p_timer; | |
d60dbb20 | 787 | long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); |
1570c1e4 CL |
788 | |
789 | if (timer) { | |
790 | if (req->rq_ntrans == 1) | |
ff839970 | 791 | rpc_update_rtt(rtt, timer, m); |
1570c1e4 CL |
792 | rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); |
793 | } | |
794 | } | |
795 | ||
9903cd1c CL |
796 | /** |
797 | * xprt_complete_rqst - called when reply processing is complete | |
1570c1e4 | 798 | * @task: RPC request that recently completed |
9903cd1c CL |
799 | * @copied: actual number of bytes received from the transport |
800 | * | |
1570c1e4 | 801 | * Caller holds transport lock. |
1da177e4 | 802 | */ |
1570c1e4 | 803 | void xprt_complete_rqst(struct rpc_task *task, int copied) |
1da177e4 | 804 | { |
1570c1e4 | 805 | struct rpc_rqst *req = task->tk_rqstp; |
fda13939 | 806 | struct rpc_xprt *xprt = req->rq_xprt; |
1da177e4 | 807 | |
1570c1e4 CL |
808 | dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", |
809 | task->tk_pid, ntohl(req->rq_xid), copied); | |
1da177e4 | 810 | |
fda13939 | 811 | xprt->stat.recvs++; |
d60dbb20 | 812 | req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); |
bbc72cea CL |
813 | if (xprt->ops->timer != NULL) |
814 | xprt_update_rtt(task); | |
ef759a2e | 815 | |
1da177e4 | 816 | list_del_init(&req->rq_list); |
1e799b67 | 817 | req->rq_private_buf.len = copied; |
dd2b63d0 RL |
818 | /* Ensure all writes are done before we update */ |
819 | /* req->rq_reply_bytes_recvd */ | |
43ac3f29 | 820 | smp_wmb(); |
dd2b63d0 | 821 | req->rq_reply_bytes_recvd = copied; |
fda13939 | 822 | rpc_wake_up_queued_task(&xprt->pending, task); |
1da177e4 | 823 | } |
12444809 | 824 | EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
1da177e4 | 825 | |
46c0ee8b | 826 | static void xprt_timer(struct rpc_task *task) |
1da177e4 | 827 | { |
46c0ee8b | 828 | struct rpc_rqst *req = task->tk_rqstp; |
1da177e4 LT |
829 | struct rpc_xprt *xprt = req->rq_xprt; |
830 | ||
5d00837b TM |
831 | if (task->tk_status != -ETIMEDOUT) |
832 | return; | |
46121cf7 | 833 | dprintk("RPC: %5u xprt_timer\n", task->tk_pid); |
1da177e4 | 834 | |
5d00837b | 835 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 | 836 | if (!req->rq_reply_bytes_recvd) { |
46c0ee8b CL |
837 | if (xprt->ops->timer) |
838 | xprt->ops->timer(task); | |
5d00837b TM |
839 | } else |
840 | task->tk_status = 0; | |
841 | spin_unlock_bh(&xprt->transport_lock); | |
1da177e4 LT |
842 | } |
843 | ||
4cfc7e60 RI |
844 | static inline int xprt_has_timer(struct rpc_xprt *xprt) |
845 | { | |
846 | return xprt->idle_timeout != 0; | |
847 | } | |
848 | ||
9903cd1c CL |
849 | /** |
850 | * xprt_prepare_transmit - reserve the transport before sending a request | |
851 | * @task: RPC task about to send a request | |
852 | * | |
1da177e4 | 853 | */ |
9903cd1c | 854 | int xprt_prepare_transmit(struct rpc_task *task) |
1da177e4 LT |
855 | { |
856 | struct rpc_rqst *req = task->tk_rqstp; | |
857 | struct rpc_xprt *xprt = req->rq_xprt; | |
858 | int err = 0; | |
859 | ||
46121cf7 | 860 | dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); |
1da177e4 | 861 | |
4a0f8c04 | 862 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 RL |
863 | if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) { |
864 | err = req->rq_reply_bytes_recvd; | |
1da177e4 LT |
865 | goto out_unlock; |
866 | } | |
43cedbf0 | 867 | if (!xprt->ops->reserve_xprt(xprt, task)) |
1da177e4 | 868 | err = -EAGAIN; |
1da177e4 | 869 | out_unlock: |
4a0f8c04 | 870 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
871 | return err; |
872 | } | |
873 | ||
e0ab53de | 874 | void xprt_end_transmit(struct rpc_task *task) |
5e5ce5be | 875 | { |
343952fa | 876 | xprt_release_write(task->tk_rqstp->rq_xprt, task); |
5e5ce5be TM |
877 | } |
878 | ||
9903cd1c CL |
879 | /** |
880 | * xprt_transmit - send an RPC request on a transport | |
881 | * @task: controlling RPC task | |
882 | * | |
883 | * We have to copy the iovec because sendmsg fiddles with its contents. | |
884 | */ | |
885 | void xprt_transmit(struct rpc_task *task) | |
1da177e4 | 886 | { |
1da177e4 LT |
887 | struct rpc_rqst *req = task->tk_rqstp; |
888 | struct rpc_xprt *xprt = req->rq_xprt; | |
15a45206 | 889 | int status, numreqs; |
1da177e4 | 890 | |
46121cf7 | 891 | dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); |
1da177e4 | 892 | |
dd2b63d0 | 893 | if (!req->rq_reply_bytes_recvd) { |
55ae1aab RL |
894 | if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { |
895 | /* | |
896 | * Add to the list only if we're expecting a reply | |
897 | */ | |
4a0f8c04 | 898 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
899 | /* Update the softirq receive buffer */ |
900 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, | |
901 | sizeof(req->rq_private_buf)); | |
902 | /* Add request to the receive list */ | |
903 | list_add_tail(&req->rq_list, &xprt->recv); | |
4a0f8c04 | 904 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 905 | xprt_reset_majortimeo(req); |
0f9dc2b1 TM |
906 | /* Turn off autodisconnect */ |
907 | del_singleshot_timer_sync(&xprt->timer); | |
1da177e4 LT |
908 | } |
909 | } else if (!req->rq_bytes_sent) | |
910 | return; | |
911 | ||
7c1d71cf | 912 | req->rq_connect_cookie = xprt->connect_cookie; |
ff839970 | 913 | req->rq_xtime = ktime_get(); |
a246b010 | 914 | status = xprt->ops->send_request(task); |
c8485e4d TM |
915 | if (status != 0) { |
916 | task->tk_status = status; | |
917 | return; | |
918 | } | |
262ca07d | 919 | |
c8485e4d | 920 | dprintk("RPC: %5u xmit complete\n", task->tk_pid); |
468f8613 | 921 | task->tk_flags |= RPC_TASK_SENT; |
c8485e4d | 922 | spin_lock_bh(&xprt->transport_lock); |
262ca07d | 923 | |
c8485e4d | 924 | xprt->ops->set_retrans_timeout(task); |
262ca07d | 925 | |
15a45206 AA |
926 | numreqs = atomic_read(&xprt->num_reqs); |
927 | if (numreqs > xprt->stat.max_slots) | |
928 | xprt->stat.max_slots = numreqs; | |
c8485e4d TM |
929 | xprt->stat.sends++; |
930 | xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; | |
931 | xprt->stat.bklog_u += xprt->backlog.qlen; | |
15a45206 AA |
932 | xprt->stat.sending_u += xprt->sending.qlen; |
933 | xprt->stat.pending_u += xprt->pending.qlen; | |
1da177e4 | 934 | |
c8485e4d TM |
935 | /* Don't race with disconnect */ |
936 | if (!xprt_connected(xprt)) | |
937 | task->tk_status = -ENOTCONN; | |
dd2b63d0 | 938 | else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) { |
55ae1aab RL |
939 | /* |
940 | * Sleep on the pending queue since | |
941 | * we're expecting a reply. | |
942 | */ | |
c8485e4d | 943 | rpc_sleep_on(&xprt->pending, task, xprt_timer); |
55ae1aab | 944 | } |
c8485e4d | 945 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
946 | } |
947 | ||
d9ba131d TM |
948 | static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) |
949 | { | |
950 | struct rpc_rqst *req = ERR_PTR(-EAGAIN); | |
951 | ||
952 | if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) | |
953 | goto out; | |
954 | req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); | |
955 | if (req != NULL) | |
956 | goto out; | |
957 | atomic_dec(&xprt->num_reqs); | |
958 | req = ERR_PTR(-ENOMEM); | |
959 | out: | |
960 | return req; | |
961 | } | |
962 | ||
963 | static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
964 | { | |
965 | if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { | |
966 | kfree(req); | |
967 | return true; | |
968 | } | |
969 | return false; | |
970 | } | |
971 | ||
ee5ebe85 | 972 | static void xprt_alloc_slot(struct rpc_task *task) |
1da177e4 LT |
973 | { |
974 | struct rpc_xprt *xprt = task->tk_xprt; | |
d9ba131d | 975 | struct rpc_rqst *req; |
1da177e4 | 976 | |
1da177e4 | 977 | if (!list_empty(&xprt->free)) { |
d9ba131d TM |
978 | req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
979 | list_del(&req->rq_list); | |
980 | goto out_init_req; | |
981 | } | |
982 | req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT); | |
983 | if (!IS_ERR(req)) | |
984 | goto out_init_req; | |
985 | switch (PTR_ERR(req)) { | |
986 | case -ENOMEM: | |
987 | rpc_delay(task, HZ >> 2); | |
988 | dprintk("RPC: dynamic allocation of request slot " | |
989 | "failed! Retrying\n"); | |
990 | break; | |
991 | case -EAGAIN: | |
992 | rpc_sleep_on(&xprt->backlog, task, NULL); | |
993 | dprintk("RPC: waiting for request slot\n"); | |
1da177e4 | 994 | } |
1da177e4 | 995 | task->tk_status = -EAGAIN; |
d9ba131d TM |
996 | return; |
997 | out_init_req: | |
998 | task->tk_status = 0; | |
999 | task->tk_rqstp = req; | |
1000 | xprt_request_init(task, xprt); | |
1da177e4 LT |
1001 | } |
1002 | ||
ee5ebe85 TM |
1003 | static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1004 | { | |
ee5ebe85 | 1005 | spin_lock(&xprt->reserve_lock); |
c25573b5 TM |
1006 | if (!xprt_dynamic_free_slot(xprt, req)) { |
1007 | memset(req, 0, sizeof(*req)); /* mark unused */ | |
1008 | list_add(&req->rq_list, &xprt->free); | |
1009 | } | |
ee5ebe85 TM |
1010 | rpc_wake_up_next(&xprt->backlog); |
1011 | spin_unlock(&xprt->reserve_lock); | |
1012 | } | |
1013 | ||
21de0a95 TM |
1014 | static void xprt_free_all_slots(struct rpc_xprt *xprt) |
1015 | { | |
1016 | struct rpc_rqst *req; | |
1017 | while (!list_empty(&xprt->free)) { | |
1018 | req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); | |
1019 | list_del(&req->rq_list); | |
1020 | kfree(req); | |
1021 | } | |
1022 | } | |
1023 | ||
d9ba131d TM |
1024 | struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
1025 | unsigned int num_prealloc, | |
1026 | unsigned int max_alloc) | |
bd1722d4 PE |
1027 | { |
1028 | struct rpc_xprt *xprt; | |
21de0a95 TM |
1029 | struct rpc_rqst *req; |
1030 | int i; | |
bd1722d4 PE |
1031 | |
1032 | xprt = kzalloc(size, GFP_KERNEL); | |
1033 | if (xprt == NULL) | |
1034 | goto out; | |
1035 | ||
21de0a95 TM |
1036 | xprt_init(xprt, net); |
1037 | ||
1038 | for (i = 0; i < num_prealloc; i++) { | |
1039 | req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); | |
1040 | if (!req) | |
1041 | break; | |
1042 | list_add(&req->rq_list, &xprt->free); | |
1043 | } | |
1044 | if (i < num_prealloc) | |
bd1722d4 | 1045 | goto out_free; |
d9ba131d TM |
1046 | if (max_alloc > num_prealloc) |
1047 | xprt->max_reqs = max_alloc; | |
1048 | else | |
1049 | xprt->max_reqs = num_prealloc; | |
1050 | xprt->min_reqs = num_prealloc; | |
1051 | atomic_set(&xprt->num_reqs, num_prealloc); | |
bd1722d4 PE |
1052 | |
1053 | return xprt; | |
1054 | ||
1055 | out_free: | |
21de0a95 | 1056 | xprt_free(xprt); |
bd1722d4 PE |
1057 | out: |
1058 | return NULL; | |
1059 | } | |
1060 | EXPORT_SYMBOL_GPL(xprt_alloc); | |
1061 | ||
e204e621 PE |
1062 | void xprt_free(struct rpc_xprt *xprt) |
1063 | { | |
37aa2133 | 1064 | put_net(xprt->xprt_net); |
21de0a95 | 1065 | xprt_free_all_slots(xprt); |
e204e621 PE |
1066 | kfree(xprt); |
1067 | } | |
1068 | EXPORT_SYMBOL_GPL(xprt_free); | |
1069 | ||
9903cd1c CL |
1070 | /** |
1071 | * xprt_reserve - allocate an RPC request slot | |
1072 | * @task: RPC task requesting a slot allocation | |
1073 | * | |
1074 | * If no more slots are available, place the task on the transport's | |
1075 | * backlog queue. | |
1076 | */ | |
1077 | void xprt_reserve(struct rpc_task *task) | |
1da177e4 LT |
1078 | { |
1079 | struct rpc_xprt *xprt = task->tk_xprt; | |
1080 | ||
43cedbf0 TM |
1081 | task->tk_status = 0; |
1082 | if (task->tk_rqstp != NULL) | |
1083 | return; | |
1084 | ||
1085 | /* Note: grabbing the xprt_lock_write() here is not strictly needed, | |
1086 | * but ensures that we throttle new slot allocation if the transport | |
1087 | * is congested (e.g. if reconnecting or if we're out of socket | |
1088 | * write buffer space). | |
1089 | */ | |
1090 | task->tk_timeout = 0; | |
1091 | task->tk_status = -EAGAIN; | |
1092 | if (!xprt_lock_write(xprt, task)) | |
1093 | return; | |
1094 | ||
0065db32 | 1095 | spin_lock(&xprt->reserve_lock); |
ee5ebe85 | 1096 | xprt_alloc_slot(task); |
0065db32 | 1097 | spin_unlock(&xprt->reserve_lock); |
43cedbf0 | 1098 | xprt_release_write(xprt, task); |
1da177e4 LT |
1099 | } |
1100 | ||
d8ed029d | 1101 | static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) |
1da177e4 | 1102 | { |
0eae88f3 | 1103 | return (__force __be32)xprt->xid++; |
1da177e4 LT |
1104 | } |
1105 | ||
1106 | static inline void xprt_init_xid(struct rpc_xprt *xprt) | |
1107 | { | |
bf3fcf89 | 1108 | xprt->xid = net_random(); |
1da177e4 LT |
1109 | } |
1110 | ||
9903cd1c | 1111 | static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) |
1da177e4 LT |
1112 | { |
1113 | struct rpc_rqst *req = task->tk_rqstp; | |
1114 | ||
d9ba131d | 1115 | INIT_LIST_HEAD(&req->rq_list); |
ba7392bb | 1116 | req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
1da177e4 LT |
1117 | req->rq_task = task; |
1118 | req->rq_xprt = xprt; | |
02107148 | 1119 | req->rq_buffer = NULL; |
1da177e4 | 1120 | req->rq_xid = xprt_alloc_xid(xprt); |
ead5e1c2 | 1121 | req->rq_release_snd_buf = NULL; |
da45828e | 1122 | xprt_reset_majortimeo(req); |
46121cf7 | 1123 | dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, |
1da177e4 LT |
1124 | req, ntohl(req->rq_xid)); |
1125 | } | |
1126 | ||
9903cd1c CL |
1127 | /** |
1128 | * xprt_release - release an RPC request slot | |
1129 | * @task: task which is finished with the slot | |
1130 | * | |
1da177e4 | 1131 | */ |
9903cd1c | 1132 | void xprt_release(struct rpc_task *task) |
1da177e4 | 1133 | { |
55ae1aab | 1134 | struct rpc_xprt *xprt; |
1da177e4 LT |
1135 | struct rpc_rqst *req; |
1136 | ||
1137 | if (!(req = task->tk_rqstp)) | |
1138 | return; | |
55ae1aab | 1139 | |
55ae1aab | 1140 | xprt = req->rq_xprt; |
0a702195 WAA |
1141 | if (task->tk_ops->rpc_count_stats != NULL) |
1142 | task->tk_ops->rpc_count_stats(task, task->tk_calldata); | |
1143 | else if (task->tk_client) | |
1144 | rpc_count_iostats(task, task->tk_client->cl_metrics); | |
4a0f8c04 | 1145 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 1146 | xprt->ops->release_xprt(xprt, task); |
a58dd398 CL |
1147 | if (xprt->ops->release_request) |
1148 | xprt->ops->release_request(task); | |
1da177e4 LT |
1149 | if (!list_empty(&req->rq_list)) |
1150 | list_del(&req->rq_list); | |
1151 | xprt->last_used = jiffies; | |
4cfc7e60 | 1152 | if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) |
a246b010 | 1153 | mod_timer(&xprt->timer, |
03bf4b70 | 1154 | xprt->last_used + xprt->idle_timeout); |
4a0f8c04 | 1155 | spin_unlock_bh(&xprt->transport_lock); |
ee5ebe85 | 1156 | if (req->rq_buffer) |
55ae1aab | 1157 | xprt->ops->buf_free(req->rq_buffer); |
a17c2153 TM |
1158 | if (req->rq_cred != NULL) |
1159 | put_rpccred(req->rq_cred); | |
1da177e4 | 1160 | task->tk_rqstp = NULL; |
ead5e1c2 BF |
1161 | if (req->rq_release_snd_buf) |
1162 | req->rq_release_snd_buf(req); | |
55ae1aab | 1163 | |
46121cf7 | 1164 | dprintk("RPC: %5u release request %p\n", task->tk_pid, req); |
ee5ebe85 TM |
1165 | if (likely(!bc_prealloc(req))) |
1166 | xprt_free_slot(xprt, req); | |
1167 | else | |
c9acb42e | 1168 | xprt_free_bc_request(req); |
1da177e4 LT |
1169 | } |
1170 | ||
21de0a95 | 1171 | static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
c2866763 | 1172 | { |
21de0a95 | 1173 | atomic_set(&xprt->count, 1); |
c2866763 CL |
1174 | |
1175 | spin_lock_init(&xprt->transport_lock); | |
1176 | spin_lock_init(&xprt->reserve_lock); | |
1177 | ||
1178 | INIT_LIST_HEAD(&xprt->free); | |
1179 | INIT_LIST_HEAD(&xprt->recv); | |
9e00abc3 | 1180 | #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
f9acac1a RL |
1181 | spin_lock_init(&xprt->bc_pa_lock); |
1182 | INIT_LIST_HEAD(&xprt->bc_pa_list); | |
9e00abc3 | 1183 | #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
f9acac1a | 1184 | |
c2866763 CL |
1185 | xprt->last_used = jiffies; |
1186 | xprt->cwnd = RPC_INITCWND; | |
a509050b | 1187 | xprt->bind_index = 0; |
c2866763 CL |
1188 | |
1189 | rpc_init_wait_queue(&xprt->binding, "xprt_binding"); | |
1190 | rpc_init_wait_queue(&xprt->pending, "xprt_pending"); | |
34006cee | 1191 | rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); |
c2866763 CL |
1192 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
1193 | ||
c2866763 CL |
1194 | xprt_init_xid(xprt); |
1195 | ||
21de0a95 | 1196 | xprt->xprt_net = get_net(net); |
8d9266ff TM |
1197 | } |
1198 | ||
1199 | /** | |
1200 | * xprt_create_transport - create an RPC transport | |
1201 | * @args: rpc transport creation arguments | |
1202 | * | |
1203 | */ | |
1204 | struct rpc_xprt *xprt_create_transport(struct xprt_create *args) | |
1205 | { | |
1206 | struct rpc_xprt *xprt; | |
1207 | struct xprt_class *t; | |
1208 | ||
1209 | spin_lock(&xprt_list_lock); | |
1210 | list_for_each_entry(t, &xprt_list, list) { | |
1211 | if (t->ident == args->ident) { | |
1212 | spin_unlock(&xprt_list_lock); | |
1213 | goto found; | |
1214 | } | |
1215 | } | |
1216 | spin_unlock(&xprt_list_lock); | |
1217 | printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); | |
1218 | return ERR_PTR(-EIO); | |
1219 | ||
1220 | found: | |
1221 | xprt = t->setup(args); | |
1222 | if (IS_ERR(xprt)) { | |
1223 | dprintk("RPC: xprt_create_transport: failed, %ld\n", | |
1224 | -PTR_ERR(xprt)); | |
21de0a95 | 1225 | goto out; |
8d9266ff | 1226 | } |
21de0a95 TM |
1227 | INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
1228 | if (xprt_has_timer(xprt)) | |
1229 | setup_timer(&xprt->timer, xprt_init_autodisconnect, | |
1230 | (unsigned long)xprt); | |
1231 | else | |
1232 | init_timer(&xprt->timer); | |
4e0038b6 TM |
1233 | |
1234 | if (strlen(args->servername) > RPC_MAXNETNAMELEN) { | |
1235 | xprt_destroy(xprt); | |
1236 | return ERR_PTR(-EINVAL); | |
1237 | } | |
1238 | xprt->servername = kstrdup(args->servername, GFP_KERNEL); | |
1239 | if (xprt->servername == NULL) { | |
1240 | xprt_destroy(xprt); | |
1241 | return ERR_PTR(-ENOMEM); | |
1242 | } | |
1243 | ||
46121cf7 | 1244 | dprintk("RPC: created transport %p with %u slots\n", xprt, |
c2866763 | 1245 | xprt->max_reqs); |
21de0a95 | 1246 | out: |
c2866763 CL |
1247 | return xprt; |
1248 | } | |
1249 | ||
9903cd1c CL |
1250 | /** |
1251 | * xprt_destroy - destroy an RPC transport, killing off all requests. | |
a8de240a | 1252 | * @xprt: transport to destroy |
9903cd1c | 1253 | * |
1da177e4 | 1254 | */ |
a8de240a | 1255 | static void xprt_destroy(struct rpc_xprt *xprt) |
1da177e4 | 1256 | { |
46121cf7 | 1257 | dprintk("RPC: destroying transport %p\n", xprt); |
0065db32 TM |
1258 | xprt->shutdown = 1; |
1259 | del_timer_sync(&xprt->timer); | |
c8541ecd | 1260 | |
f6a1cc89 TM |
1261 | rpc_destroy_wait_queue(&xprt->binding); |
1262 | rpc_destroy_wait_queue(&xprt->pending); | |
1263 | rpc_destroy_wait_queue(&xprt->sending); | |
f6a1cc89 | 1264 | rpc_destroy_wait_queue(&xprt->backlog); |
c3ae62ae | 1265 | cancel_work_sync(&xprt->task_cleanup); |
4e0038b6 | 1266 | kfree(xprt->servername); |
c8541ecd CL |
1267 | /* |
1268 | * Tear down transport state and free the rpc_xprt | |
1269 | */ | |
a246b010 | 1270 | xprt->ops->destroy(xprt); |
6b6ca86b | 1271 | } |
1da177e4 | 1272 | |
6b6ca86b TM |
1273 | /** |
1274 | * xprt_put - release a reference to an RPC transport. | |
1275 | * @xprt: pointer to the transport | |
1276 | * | |
1277 | */ | |
1278 | void xprt_put(struct rpc_xprt *xprt) | |
1279 | { | |
a8de240a TM |
1280 | if (atomic_dec_and_test(&xprt->count)) |
1281 | xprt_destroy(xprt); | |
6b6ca86b TM |
1282 | } |
1283 | ||
1284 | /** | |
1285 | * xprt_get - return a reference to an RPC transport. | |
1286 | * @xprt: pointer to the transport | |
1287 | * | |
1288 | */ | |
1289 | struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) | |
1290 | { | |
a8de240a TM |
1291 | if (atomic_inc_not_zero(&xprt->count)) |
1292 | return xprt; | |
1293 | return NULL; | |
1da177e4 | 1294 | } |