1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/net/sunrpc/xprt.c |
4 | * |
5 | * This is a generic RPC call interface supporting congestion avoidance, |
6 | * and asynchronous calls. |
7 | * |
8 | * The interface works like this: |
9 | * |
10 | * - When a process places a call, it allocates a request slot if |
11 | * one is available. Otherwise, it sleeps on the backlog queue |
12 | * (xprt_reserve). |
13 | * - Next, the caller puts together the RPC message, stuffs it into |
14 | * the request struct, and calls xprt_transmit(). |
15 | * - xprt_transmit sends the message and installs the caller on the |
16 | * transport's wait list. At the same time, if a reply is expected, |
17 | * it installs a timer that is run after the packet's timeout has |
18 | * expired. |
19 | * - When a packet arrives, the data_ready handler walks the list of |
20 | * pending requests for that transport. If a matching XID is found, the |
21 | * caller is woken up, and the timer removed. |
22 | * - When no reply arrives within the timeout interval, the timer is |
23 | * fired by the kernel and runs xprt_timer(). It either adjusts the |
24 | * timeout values (minor timeout) or wakes up the caller with a status |
25 | * of -ETIMEDOUT. |
26 | * - When the caller receives a notification from RPC that a reply arrived, |
27 | * it should release the RPC slot, and process the reply. |
28 | * If the call timed out, it may choose to retry the operation by |
29 | * adjusting the initial timeout value, and simply calling rpc_call |
30 | * again. |
31 | * |
32 | * Support for async RPC is done through a set of RPC-specific scheduling |
33 | * primitives that `transparently' work for processes as well as async |
34 | * tasks that rely on callbacks. |
35 | * |
36 | * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> |
37 | * |
38 | * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> |
39 | */ |
40 | |
41 | #include <linux/module.h> |
42 | |
43 | #include <linux/types.h> |
44 | #include <linux/interrupt.h> |
45 | #include <linux/workqueue.h> |
46 | #include <linux/net.h> |
47 | #include <linux/ktime.h> |
48 | |
49 | #include <linux/sunrpc/clnt.h> |
50 | #include <linux/sunrpc/metrics.h> |
51 | #include <linux/sunrpc/bc_xprt.h> |
52 | #include <linux/rcupdate.h> |
53 | #include <linux/sched/mm.h> |
54 | |
55 | #include <trace/events/sunrpc.h> |
56 | |
57 | #include "sunrpc.h" |
58 | #include "sysfs.h" |
59 | #include "fail.h" |
60 | |
61 | /* |
62 | * Local variables |
63 | */ |
64 | |
65 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
66 | # define RPCDBG_FACILITY RPCDBG_XPRT |
67 | #endif |
68 | |
69 | /* |
70 | * Local functions |
71 | */ |
72 | static void xprt_init(struct rpc_xprt *xprt, struct net *net); |
73 | static __be32 xprt_alloc_xid(struct rpc_xprt *xprt); |
74 | static void xprt_destroy(struct rpc_xprt *xprt); |
75 | static void xprt_request_init(struct rpc_task *task); |
76 | static int xprt_request_prepare(struct rpc_rqst *req, struct xdr_buf *buf); |
77 | |
78 | static DEFINE_SPINLOCK(xprt_list_lock); |
79 | static LIST_HEAD(xprt_list); |
80 | |
81 | static unsigned long xprt_request_timeout(const struct rpc_rqst *req) |
82 | { |
83 | unsigned long timeout = jiffies + req->rq_timeout; |
84 | |
85 | if (time_before(timeout, req->rq_majortimeo)) |
86 | return timeout; |
87 | return req->rq_majortimeo; |
88 | } |
89 | |
90 | /** |
91 | * xprt_register_transport - register a transport implementation |
92 | * @transport: transport to register |
93 | * |
94 | * If a transport implementation is loaded as a kernel module, it can |
95 | * call this interface to make itself known to the RPC client. |
96 | * |
97 | * Returns: |
98 | * 0: transport successfully registered |
99 | * -EEXIST: transport already registered |
100 | * -EINVAL: transport module being unloaded |
101 | */ |
102 | int xprt_register_transport(struct xprt_class *transport) |
103 | { |
104 | struct xprt_class *t; |
105 | int result; |
106 | |
107 | result = -EEXIST; |
108 | spin_lock(lock: &xprt_list_lock); |
109 | list_for_each_entry(t, &xprt_list, list) { |
110 | /* don't register the same transport class twice */ |
111 | if (t->ident == transport->ident) |
112 | goto out; |
113 | } |
114 | |
115 | list_add_tail(new: &transport->list, head: &xprt_list); |
116 | printk(KERN_INFO "RPC: Registered %s transport module.\n" , |
117 | transport->name); |
118 | result = 0; |
119 | |
120 | out: |
121 | spin_unlock(lock: &xprt_list_lock); |
122 | return result; |
123 | } |
124 | EXPORT_SYMBOL_GPL(xprt_register_transport); |
125 | |
126 | /** |
127 | * xprt_unregister_transport - unregister a transport implementation |
128 | * @transport: transport to unregister |
129 | * |
130 | * Returns: |
131 | * 0: transport successfully unregistered |
132 | * -ENOENT: transport never registered |
133 | */ |
134 | int xprt_unregister_transport(struct xprt_class *transport) |
135 | { |
136 | struct xprt_class *t; |
137 | int result; |
138 | |
139 | result = 0; |
140 | spin_lock(lock: &xprt_list_lock); |
141 | list_for_each_entry(t, &xprt_list, list) { |
142 | if (t == transport) { |
143 | printk(KERN_INFO |
144 | "RPC: Unregistered %s transport module.\n" , |
145 | transport->name); |
146 | list_del_init(entry: &transport->list); |
147 | goto out; |
148 | } |
149 | } |
150 | result = -ENOENT; |
151 | |
152 | out: |
153 | spin_unlock(lock: &xprt_list_lock); |
154 | return result; |
155 | } |
156 | EXPORT_SYMBOL_GPL(xprt_unregister_transport); |
157 | |
158 | static void |
159 | xprt_class_release(const struct xprt_class *t) |
160 | { |
161 | module_put(module: t->owner); |
162 | } |
163 | |
164 | static const struct xprt_class * |
165 | xprt_class_find_by_ident_locked(int ident) |
166 | { |
167 | const struct xprt_class *t; |
168 | |
169 | list_for_each_entry(t, &xprt_list, list) { |
170 | if (t->ident != ident) |
171 | continue; |
172 | if (!try_module_get(module: t->owner)) |
173 | continue; |
174 | return t; |
175 | } |
176 | return NULL; |
177 | } |
178 | |
179 | static const struct xprt_class * |
180 | xprt_class_find_by_ident(int ident) |
181 | { |
182 | const struct xprt_class *t; |
183 | |
184 | spin_lock(lock: &xprt_list_lock); |
185 | t = xprt_class_find_by_ident_locked(ident); |
186 | spin_unlock(lock: &xprt_list_lock); |
187 | return t; |
188 | } |
189 | |
190 | static const struct xprt_class * |
191 | xprt_class_find_by_netid_locked(const char *netid) |
192 | { |
193 | const struct xprt_class *t; |
194 | unsigned int i; |
195 | |
196 | list_for_each_entry(t, &xprt_list, list) { |
197 | for (i = 0; t->netid[i][0] != '\0'; i++) { |
198 | if (strcmp(t->netid[i], netid) != 0) |
199 | continue; |
200 | if (!try_module_get(module: t->owner)) |
201 | continue; |
202 | return t; |
203 | } |
204 | } |
205 | return NULL; |
206 | } |
207 | |
208 | static const struct xprt_class * |
209 | xprt_class_find_by_netid(const char *netid) |
210 | { |
211 | const struct xprt_class *t; |
212 | |
213 | spin_lock(lock: &xprt_list_lock); |
214 | t = xprt_class_find_by_netid_locked(netid); |
215 | if (!t) { |
216 | spin_unlock(lock: &xprt_list_lock); |
217 | request_module("rpc%s" , netid); |
218 | spin_lock(lock: &xprt_list_lock); |
219 | t = xprt_class_find_by_netid_locked(netid); |
220 | } |
221 | spin_unlock(lock: &xprt_list_lock); |
222 | return t; |
223 | } |
224 | |
225 | /** |
226 | * xprt_find_transport_ident - convert a netid into a transport identifier |
227 | * @netid: transport to load |
228 | * |
229 | * Returns: |
230 | * > 0: transport identifier |
231 | * -ENOENT: transport module not available |
232 | */ |
233 | int xprt_find_transport_ident(const char *netid) |
234 | { |
235 | const struct xprt_class *t; |
236 | int ret; |
237 | |
238 | t = xprt_class_find_by_netid(netid); |
239 | if (!t) |
240 | return -ENOENT; |
241 | ret = t->ident; |
242 | xprt_class_release(t); |
243 | return ret; |
244 | } |
245 | EXPORT_SYMBOL_GPL(xprt_find_transport_ident); |
246 | |
247 | static void xprt_clear_locked(struct rpc_xprt *xprt) |
248 | { |
249 | xprt->snd_task = NULL; |
250 | if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) |
251 | clear_bit_unlock(XPRT_LOCKED, addr: &xprt->state); |
252 | else |
253 | queue_work(wq: xprtiod_workqueue, work: &xprt->task_cleanup); |
254 | } |
255 | |
256 | /** |
257 | * xprt_reserve_xprt - serialize write access to transports |
258 | * @task: task that is requesting access to the transport |
259 | * @xprt: pointer to the target transport |
260 | * |
261 | * This prevents mixing the payload of separate requests, and prevents |
262 | * transport connects from colliding with writes. No congestion control |
263 | * is provided. |
264 | */ |
265 | int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
266 | { |
267 | struct rpc_rqst *req = task->tk_rqstp; |
268 | |
269 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state)) { |
270 | if (task == xprt->snd_task) |
271 | goto out_locked; |
272 | goto out_sleep; |
273 | } |
274 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
275 | goto out_unlock; |
276 | xprt->snd_task = task; |
277 | |
278 | out_locked: |
279 | trace_xprt_reserve_xprt(xprt, task); |
280 | return 1; |
281 | |
282 | out_unlock: |
283 | xprt_clear_locked(xprt); |
284 | out_sleep: |
285 | task->tk_status = -EAGAIN; |
286 | if (RPC_IS_SOFT(task) || RPC_IS_SOFTCONN(task)) |
287 | rpc_sleep_on_timeout(queue: &xprt->sending, task, NULL, |
288 | timeout: xprt_request_timeout(req)); |
289 | else |
290 | rpc_sleep_on(&xprt->sending, task, NULL); |
291 | return 0; |
292 | } |
293 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
294 | |
295 | static bool |
296 | xprt_need_congestion_window_wait(struct rpc_xprt *xprt) |
297 | { |
298 | return test_bit(XPRT_CWND_WAIT, &xprt->state); |
299 | } |
300 | |
301 | static void |
302 | xprt_set_congestion_window_wait(struct rpc_xprt *xprt) |
303 | { |
304 | if (!list_empty(head: &xprt->xmit_queue)) { |
305 | /* Peek at head of queue to see if it can make progress */ |
306 | if (list_first_entry(&xprt->xmit_queue, struct rpc_rqst, |
307 | rq_xmit)->rq_cong) |
308 | return; |
309 | } |
310 | set_bit(XPRT_CWND_WAIT, addr: &xprt->state); |
311 | } |
312 | |
313 | static void |
314 | xprt_test_and_clear_congestion_window_wait(struct rpc_xprt *xprt) |
315 | { |
316 | if (!RPCXPRT_CONGESTED(xprt)) |
317 | clear_bit(XPRT_CWND_WAIT, addr: &xprt->state); |
318 | } |
319 | |
320 | /* |
321 | * xprt_reserve_xprt_cong - serialize write access to transports |
322 | * @task: task that is requesting access to the transport |
323 | * |
324 | * Same as xprt_reserve_xprt, but Van Jacobson congestion control is |
325 | * integrated into the decision of whether a request is allowed to be |
326 | * woken up and given access to the transport. |
327 | * Note that the lock is only granted if we know there are free slots. |
328 | */ |
329 | int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
330 | { |
331 | struct rpc_rqst *req = task->tk_rqstp; |
332 | |
333 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state)) { |
334 | if (task == xprt->snd_task) |
335 | goto out_locked; |
336 | goto out_sleep; |
337 | } |
338 | if (req == NULL) { |
339 | xprt->snd_task = task; |
340 | goto out_locked; |
341 | } |
342 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
343 | goto out_unlock; |
344 | if (!xprt_need_congestion_window_wait(xprt)) { |
345 | xprt->snd_task = task; |
346 | goto out_locked; |
347 | } |
348 | out_unlock: |
349 | xprt_clear_locked(xprt); |
350 | out_sleep: |
351 | task->tk_status = -EAGAIN; |
352 | if (RPC_IS_SOFT(task) || RPC_IS_SOFTCONN(task)) |
353 | rpc_sleep_on_timeout(queue: &xprt->sending, task, NULL, |
354 | timeout: xprt_request_timeout(req)); |
355 | else |
356 | rpc_sleep_on(&xprt->sending, task, NULL); |
357 | return 0; |
358 | out_locked: |
359 | trace_xprt_reserve_cong(xprt, task); |
360 | return 1; |
361 | } |
362 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
363 | |
364 | static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
365 | { |
366 | int retval; |
367 | |
368 | if (test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == task) |
369 | return 1; |
370 | spin_lock(lock: &xprt->transport_lock); |
371 | retval = xprt->ops->reserve_xprt(xprt, task); |
372 | spin_unlock(lock: &xprt->transport_lock); |
373 | return retval; |
374 | } |
375 | |
376 | static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
377 | { |
378 | struct rpc_xprt *xprt = data; |
379 | |
380 | xprt->snd_task = task; |
381 | return true; |
382 | } |
383 | |
384 | static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
385 | { |
386 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state)) |
387 | return; |
388 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
389 | goto out_unlock; |
390 | if (rpc_wake_up_first_on_wq(wq: xprtiod_workqueue, &xprt->sending, |
391 | __xprt_lock_write_func, xprt)) |
392 | return; |
393 | out_unlock: |
394 | xprt_clear_locked(xprt); |
395 | } |
396 | |
397 | static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) |
398 | { |
399 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state)) |
400 | return; |
401 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
402 | goto out_unlock; |
403 | if (xprt_need_congestion_window_wait(xprt)) |
404 | goto out_unlock; |
405 | if (rpc_wake_up_first_on_wq(wq: xprtiod_workqueue, &xprt->sending, |
406 | __xprt_lock_write_func, xprt)) |
407 | return; |
408 | out_unlock: |
409 | xprt_clear_locked(xprt); |
410 | } |
411 | |
412 | /** |
413 | * xprt_release_xprt - allow other requests to use a transport |
414 | * @xprt: transport with other tasks potentially waiting |
415 | * @task: task that is releasing access to the transport |
416 | * |
417 | * Note that "task" can be NULL. No congestion control is provided. |
418 | */ |
419 | void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
420 | { |
421 | if (xprt->snd_task == task) { |
422 | xprt_clear_locked(xprt); |
423 | __xprt_lock_write_next(xprt); |
424 | } |
425 | trace_xprt_release_xprt(xprt, task); |
426 | } |
427 | EXPORT_SYMBOL_GPL(xprt_release_xprt); |
428 | |
429 | /** |
430 | * xprt_release_xprt_cong - allow other requests to use a transport |
431 | * @xprt: transport with other tasks potentially waiting |
432 | * @task: task that is releasing access to the transport |
433 | * |
434 | * Note that "task" can be NULL. Another task is awoken to use the |
435 | * transport if the transport's congestion window allows it. |
436 | */ |
437 | void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
438 | { |
439 | if (xprt->snd_task == task) { |
440 | xprt_clear_locked(xprt); |
441 | __xprt_lock_write_next_cong(xprt); |
442 | } |
443 | trace_xprt_release_cong(xprt, task); |
444 | } |
445 | EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
446 | |
447 | void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) |
448 | { |
449 | if (xprt->snd_task != task) |
450 | return; |
451 | spin_lock(lock: &xprt->transport_lock); |
452 | xprt->ops->release_xprt(xprt, task); |
453 | spin_unlock(lock: &xprt->transport_lock); |
454 | } |
455 | |
456 | /* |
457 | * Van Jacobson congestion avoidance. Check if the congestion window |
458 | * overflowed. Put the task to sleep if this is the case. |
459 | */ |
460 | static int |
461 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) |
462 | { |
463 | if (req->rq_cong) |
464 | return 1; |
465 | trace_xprt_get_cong(xprt, task: req->rq_task); |
466 | if (RPCXPRT_CONGESTED(xprt)) { |
467 | xprt_set_congestion_window_wait(xprt); |
468 | return 0; |
469 | } |
470 | req->rq_cong = 1; |
471 | xprt->cong += RPC_CWNDSCALE; |
472 | return 1; |
473 | } |
474 | |
475 | /* |
476 | * Adjust the congestion window, and wake up the next task |
477 | * that has been sleeping due to congestion |
478 | */ |
479 | static void |
480 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) |
481 | { |
482 | if (!req->rq_cong) |
483 | return; |
484 | req->rq_cong = 0; |
485 | xprt->cong -= RPC_CWNDSCALE; |
486 | xprt_test_and_clear_congestion_window_wait(xprt); |
487 | trace_xprt_put_cong(xprt, task: req->rq_task); |
488 | __xprt_lock_write_next_cong(xprt); |
489 | } |
490 | |
491 | /** |
492 | * xprt_request_get_cong - Request congestion control credits |
493 | * @xprt: pointer to transport |
494 | * @req: pointer to RPC request |
495 | * |
496 | * Useful for transports that require congestion control. |
497 | */ |
498 | bool |
499 | xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) |
500 | { |
501 | bool ret = false; |
502 | |
503 | if (req->rq_cong) |
504 | return true; |
505 | spin_lock(lock: &xprt->transport_lock); |
506 | ret = __xprt_get_cong(xprt, req) != 0; |
507 | spin_unlock(lock: &xprt->transport_lock); |
508 | return ret; |
509 | } |
510 | EXPORT_SYMBOL_GPL(xprt_request_get_cong); |
511 | |
512 | /** |
513 | * xprt_release_rqst_cong - housekeeping when request is complete |
514 | * @task: RPC request that recently completed |
515 | * |
516 | * Useful for transports that require congestion control. |
517 | */ |
518 | void xprt_release_rqst_cong(struct rpc_task *task) |
519 | { |
520 | struct rpc_rqst *req = task->tk_rqstp; |
521 | |
522 | __xprt_put_cong(xprt: req->rq_xprt, req); |
523 | } |
524 | EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
525 | |
526 | static void xprt_clear_congestion_window_wait_locked(struct rpc_xprt *xprt) |
527 | { |
528 | if (test_and_clear_bit(XPRT_CWND_WAIT, addr: &xprt->state)) |
529 | __xprt_lock_write_next_cong(xprt); |
530 | } |
531 | |
532 | /* |
533 | * Clear the congestion window wait flag and wake up the next |
534 | * entry on xprt->sending |
535 | */ |
536 | static void |
537 | xprt_clear_congestion_window_wait(struct rpc_xprt *xprt) |
538 | { |
539 | if (test_and_clear_bit(XPRT_CWND_WAIT, addr: &xprt->state)) { |
540 | spin_lock(lock: &xprt->transport_lock); |
541 | __xprt_lock_write_next_cong(xprt); |
542 | spin_unlock(lock: &xprt->transport_lock); |
543 | } |
544 | } |
545 | |
546 | /** |
547 | * xprt_adjust_cwnd - adjust transport congestion window |
548 | * @xprt: pointer to xprt |
549 | * @task: recently completed RPC request used to adjust window |
550 | * @result: result code of completed RPC request |
551 | * |
552 | * The transport code maintains an estimate on the maximum number of out- |
553 | * standing RPC requests, using a smoothed version of the congestion |
554 | * avoidance implemented in 44BSD. This is basically the Van Jacobson |
555 | * congestion algorithm: If a retransmit occurs, the congestion window is |
556 | * halved; otherwise, it is incremented by 1/cwnd when |
557 | * |
558 | * - a reply is received and |
559 | * - a full number of requests are outstanding and |
560 | * - the congestion window hasn't been updated recently. |
561 | */ |
562 | void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) |
563 | { |
564 | struct rpc_rqst *req = task->tk_rqstp; |
565 | unsigned long cwnd = xprt->cwnd; |
566 | |
567 | if (result >= 0 && cwnd <= xprt->cong) { |
568 | /* The (cwnd >> 1) term makes sure |
569 | * the result gets rounded properly. */ |
570 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; |
571 | if (cwnd > RPC_MAXCWND(xprt)) |
572 | cwnd = RPC_MAXCWND(xprt); |
573 | __xprt_lock_write_next_cong(xprt); |
574 | } else if (result == -ETIMEDOUT) { |
575 | cwnd >>= 1; |
576 | if (cwnd < RPC_CWNDSCALE) |
577 | cwnd = RPC_CWNDSCALE; |
578 | } |
579 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n" , |
580 | xprt->cong, xprt->cwnd, cwnd); |
581 | xprt->cwnd = cwnd; |
582 | __xprt_put_cong(xprt, req); |
583 | } |
584 | EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
585 | |
586 | /** |
587 | * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue |
588 | * @xprt: transport with waiting tasks |
589 | * @status: result code to plant in each task before waking it |
590 | * |
591 | */ |
592 | void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) |
593 | { |
594 | if (status < 0) |
595 | rpc_wake_up_status(&xprt->pending, status); |
596 | else |
597 | rpc_wake_up(&xprt->pending); |
598 | } |
599 | EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
600 | |
601 | /** |
602 | * xprt_wait_for_buffer_space - wait for transport output buffer to clear |
603 | * @xprt: transport |
604 | * |
605 | * Note that we only set the timer for the case of RPC_IS_SOFT(), since |
606 | * we don't in general want to force a socket disconnection due to |
607 | * an incomplete RPC call transmission. |
608 | */ |
609 | void xprt_wait_for_buffer_space(struct rpc_xprt *xprt) |
610 | { |
611 | set_bit(XPRT_WRITE_SPACE, addr: &xprt->state); |
612 | } |
613 | EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
614 | |
615 | static bool |
616 | xprt_clear_write_space_locked(struct rpc_xprt *xprt) |
617 | { |
618 | if (test_and_clear_bit(XPRT_WRITE_SPACE, addr: &xprt->state)) { |
619 | __xprt_lock_write_next(xprt); |
620 | dprintk("RPC: write space: waking waiting task on " |
621 | "xprt %p\n" , xprt); |
622 | return true; |
623 | } |
624 | return false; |
625 | } |
626 | |
627 | /** |
628 | * xprt_write_space - wake the task waiting for transport output buffer space |
629 | * @xprt: transport with waiting tasks |
630 | * |
631 | * Can be called in a soft IRQ context, so xprt_write_space never sleeps. |
632 | */ |
633 | bool xprt_write_space(struct rpc_xprt *xprt) |
634 | { |
635 | bool ret; |
636 | |
637 | if (!test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
638 | return false; |
639 | spin_lock(lock: &xprt->transport_lock); |
640 | ret = xprt_clear_write_space_locked(xprt); |
641 | spin_unlock(lock: &xprt->transport_lock); |
642 | return ret; |
643 | } |
644 | EXPORT_SYMBOL_GPL(xprt_write_space); |
645 | |
646 | static unsigned long xprt_abs_ktime_to_jiffies(ktime_t abstime) |
647 | { |
648 | s64 delta = ktime_to_ns(kt: ktime_get() - abstime); |
649 | return likely(delta >= 0) ? |
650 | jiffies - nsecs_to_jiffies(n: delta) : |
651 | jiffies + nsecs_to_jiffies(n: -delta); |
652 | } |
653 | |
654 | static unsigned long xprt_calc_majortimeo(struct rpc_rqst *req) |
655 | { |
656 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
657 | unsigned long majortimeo = req->rq_timeout; |
658 | |
659 | if (to->to_exponential) |
660 | majortimeo <<= to->to_retries; |
661 | else |
662 | majortimeo += to->to_increment * to->to_retries; |
663 | if (majortimeo > to->to_maxval || majortimeo == 0) |
664 | majortimeo = to->to_maxval; |
665 | return majortimeo; |
666 | } |
667 | |
668 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
669 | { |
670 | req->rq_majortimeo += xprt_calc_majortimeo(req); |
671 | } |
672 | |
673 | static void xprt_reset_minortimeo(struct rpc_rqst *req) |
674 | { |
675 | req->rq_minortimeo += req->rq_timeout; |
676 | } |
677 | |
678 | static void xprt_init_majortimeo(struct rpc_task *task, struct rpc_rqst *req) |
679 | { |
680 | unsigned long time_init; |
681 | struct rpc_xprt *xprt = req->rq_xprt; |
682 | |
683 | if (likely(xprt && xprt_connected(xprt))) |
684 | time_init = jiffies; |
685 | else |
686 | time_init = xprt_abs_ktime_to_jiffies(abstime: task->tk_start); |
687 | req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
688 | req->rq_majortimeo = time_init + xprt_calc_majortimeo(req); |
689 | req->rq_minortimeo = time_init + req->rq_timeout; |
690 | } |
691 | |
692 | /** |
693 | * xprt_adjust_timeout - adjust timeout values for next retransmit |
694 | * @req: RPC request containing parameters to use for the adjustment |
695 | * |
696 | */ |
697 | int xprt_adjust_timeout(struct rpc_rqst *req) |
698 | { |
699 | struct rpc_xprt *xprt = req->rq_xprt; |
700 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
701 | int status = 0; |
702 | |
703 | if (time_before(jiffies, req->rq_majortimeo)) { |
704 | if (time_before(jiffies, req->rq_minortimeo)) |
705 | return status; |
706 | if (to->to_exponential) |
707 | req->rq_timeout <<= 1; |
708 | else |
709 | req->rq_timeout += to->to_increment; |
710 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) |
711 | req->rq_timeout = to->to_maxval; |
712 | req->rq_retries++; |
713 | } else { |
714 | req->rq_timeout = to->to_initval; |
715 | req->rq_retries = 0; |
716 | xprt_reset_majortimeo(req); |
717 | /* Reset the RTT counters == "slow start" */ |
718 | spin_lock(lock: &xprt->transport_lock); |
719 | rpc_init_rtt(rt: req->rq_task->tk_client->cl_rtt, timeo: to->to_initval); |
720 | spin_unlock(lock: &xprt->transport_lock); |
721 | status = -ETIMEDOUT; |
722 | } |
723 | xprt_reset_minortimeo(req); |
724 | |
725 | if (req->rq_timeout == 0) { |
726 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n" ); |
727 | req->rq_timeout = 5 * HZ; |
728 | } |
729 | return status; |
730 | } |
731 | |
732 | static void xprt_autoclose(struct work_struct *work) |
733 | { |
734 | struct rpc_xprt *xprt = |
735 | container_of(work, struct rpc_xprt, task_cleanup); |
736 | unsigned int pflags = memalloc_nofs_save(); |
737 | |
738 | trace_xprt_disconnect_auto(xprt); |
739 | xprt->connect_cookie++; |
740 | smp_mb__before_atomic(); |
741 | clear_bit(XPRT_CLOSE_WAIT, addr: &xprt->state); |
742 | xprt->ops->close(xprt); |
743 | xprt_release_write(xprt, NULL); |
744 | wake_up_bit(word: &xprt->state, XPRT_LOCKED); |
745 | memalloc_nofs_restore(flags: pflags); |
746 | } |
747 | |
748 | /** |
749 | * xprt_disconnect_done - mark a transport as disconnected |
750 | * @xprt: transport to flag for disconnect |
751 | * |
752 | */ |
753 | void xprt_disconnect_done(struct rpc_xprt *xprt) |
754 | { |
755 | trace_xprt_disconnect_done(xprt); |
756 | spin_lock(lock: &xprt->transport_lock); |
757 | xprt_clear_connected(xprt); |
758 | xprt_clear_write_space_locked(xprt); |
759 | xprt_clear_congestion_window_wait_locked(xprt); |
760 | xprt_wake_pending_tasks(xprt, -ENOTCONN); |
761 | spin_unlock(lock: &xprt->transport_lock); |
762 | } |
763 | EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
764 | |
765 | /** |
766 | * xprt_schedule_autoclose_locked - Try to schedule an autoclose RPC call |
767 | * @xprt: transport to disconnect |
768 | */ |
769 | static void xprt_schedule_autoclose_locked(struct rpc_xprt *xprt) |
770 | { |
771 | if (test_and_set_bit(XPRT_CLOSE_WAIT, addr: &xprt->state)) |
772 | return; |
773 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state) == 0) |
774 | queue_work(wq: xprtiod_workqueue, work: &xprt->task_cleanup); |
775 | else if (xprt->snd_task && !test_bit(XPRT_SND_IS_COOKIE, &xprt->state)) |
776 | rpc_wake_up_queued_task_set_status(&xprt->pending, |
777 | xprt->snd_task, -ENOTCONN); |
778 | } |
779 | |
780 | /** |
781 | * xprt_force_disconnect - force a transport to disconnect |
782 | * @xprt: transport to disconnect |
783 | * |
784 | */ |
785 | void xprt_force_disconnect(struct rpc_xprt *xprt) |
786 | { |
787 | trace_xprt_disconnect_force(xprt); |
788 | |
789 | /* Don't race with the test_bit() in xprt_clear_locked() */ |
790 | spin_lock(lock: &xprt->transport_lock); |
791 | xprt_schedule_autoclose_locked(xprt); |
792 | spin_unlock(lock: &xprt->transport_lock); |
793 | } |
794 | EXPORT_SYMBOL_GPL(xprt_force_disconnect); |
795 | |
796 | static unsigned int |
797 | xprt_connect_cookie(struct rpc_xprt *xprt) |
798 | { |
799 | return READ_ONCE(xprt->connect_cookie); |
800 | } |
801 | |
802 | static bool |
803 | xprt_request_retransmit_after_disconnect(struct rpc_task *task) |
804 | { |
805 | struct rpc_rqst *req = task->tk_rqstp; |
806 | struct rpc_xprt *xprt = req->rq_xprt; |
807 | |
808 | return req->rq_connect_cookie != xprt_connect_cookie(xprt) || |
809 | !xprt_connected(xprt); |
810 | } |
811 | |
812 | /** |
813 | * xprt_conditional_disconnect - force a transport to disconnect |
814 | * @xprt: transport to disconnect |
815 | * @cookie: 'connection cookie' |
816 | * |
817 | * This attempts to break the connection if and only if 'cookie' matches |
818 | * the current transport 'connection cookie'. It ensures that we don't |
819 | * try to break the connection more than once when we need to retransmit |
820 | * a batch of RPC requests. |
821 | * |
822 | */ |
823 | void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) |
824 | { |
825 | /* Don't race with the test_bit() in xprt_clear_locked() */ |
826 | spin_lock(lock: &xprt->transport_lock); |
827 | if (cookie != xprt->connect_cookie) |
828 | goto out; |
829 | if (test_bit(XPRT_CLOSING, &xprt->state)) |
830 | goto out; |
831 | xprt_schedule_autoclose_locked(xprt); |
832 | out: |
833 | spin_unlock(lock: &xprt->transport_lock); |
834 | } |
835 | |
836 | static bool |
837 | xprt_has_timer(const struct rpc_xprt *xprt) |
838 | { |
839 | return xprt->idle_timeout != 0; |
840 | } |
841 | |
842 | static void |
843 | xprt_schedule_autodisconnect(struct rpc_xprt *xprt) |
844 | __must_hold(&xprt->transport_lock) |
845 | { |
846 | xprt->last_used = jiffies; |
847 | if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt)) |
848 | mod_timer(timer: &xprt->timer, expires: xprt->last_used + xprt->idle_timeout); |
849 | } |
850 | |
851 | static void |
852 | xprt_init_autodisconnect(struct timer_list *t) |
853 | { |
854 | struct rpc_xprt *xprt = from_timer(xprt, t, timer); |
855 | |
856 | if (!RB_EMPTY_ROOT(&xprt->recv_queue)) |
857 | return; |
858 | /* Reset xprt->last_used to avoid connect/autodisconnect cycling */ |
859 | xprt->last_used = jiffies; |
860 | if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state)) |
861 | return; |
862 | queue_work(wq: xprtiod_workqueue, work: &xprt->task_cleanup); |
863 | } |
864 | |
865 | #if IS_ENABLED(CONFIG_FAIL_SUNRPC) |
866 | static void xprt_inject_disconnect(struct rpc_xprt *xprt) |
867 | { |
868 | if (!fail_sunrpc.ignore_client_disconnect && |
869 | should_fail(attr: &fail_sunrpc.attr, size: 1)) |
870 | xprt->ops->inject_disconnect(xprt); |
871 | } |
872 | #else |
873 | static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) |
874 | { |
875 | } |
876 | #endif |
877 | |
878 | bool xprt_lock_connect(struct rpc_xprt *xprt, |
879 | struct rpc_task *task, |
880 | void *cookie) |
881 | { |
882 | bool ret = false; |
883 | |
884 | spin_lock(lock: &xprt->transport_lock); |
885 | if (!test_bit(XPRT_LOCKED, &xprt->state)) |
886 | goto out; |
887 | if (xprt->snd_task != task) |
888 | goto out; |
889 | set_bit(XPRT_SND_IS_COOKIE, addr: &xprt->state); |
890 | xprt->snd_task = cookie; |
891 | ret = true; |
892 | out: |
893 | spin_unlock(lock: &xprt->transport_lock); |
894 | return ret; |
895 | } |
896 | EXPORT_SYMBOL_GPL(xprt_lock_connect); |
897 | |
898 | void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) |
899 | { |
900 | spin_lock(lock: &xprt->transport_lock); |
901 | if (xprt->snd_task != cookie) |
902 | goto out; |
903 | if (!test_bit(XPRT_LOCKED, &xprt->state)) |
904 | goto out; |
905 | xprt->snd_task =NULL; |
906 | clear_bit(XPRT_SND_IS_COOKIE, addr: &xprt->state); |
907 | xprt->ops->release_xprt(xprt, NULL); |
908 | xprt_schedule_autodisconnect(xprt); |
909 | out: |
910 | spin_unlock(lock: &xprt->transport_lock); |
911 | wake_up_bit(word: &xprt->state, XPRT_LOCKED); |
912 | } |
913 | EXPORT_SYMBOL_GPL(xprt_unlock_connect); |
914 | |
915 | /** |
916 | * xprt_connect - schedule a transport connect operation |
917 | * @task: RPC task that is requesting the connect |
918 | * |
919 | */ |
920 | void xprt_connect(struct rpc_task *task) |
921 | { |
922 | struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
923 | |
924 | trace_xprt_connect(xprt); |
925 | |
926 | if (!xprt_bound(xprt)) { |
927 | task->tk_status = -EAGAIN; |
928 | return; |
929 | } |
930 | if (!xprt_lock_write(xprt, task)) |
931 | return; |
932 | |
933 | if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { |
934 | task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie; |
935 | rpc_sleep_on_timeout(queue: &xprt->pending, task, NULL, |
936 | timeout: xprt_request_timeout(req: task->tk_rqstp)); |
937 | |
938 | if (test_bit(XPRT_CLOSING, &xprt->state)) |
939 | return; |
940 | if (xprt_test_and_set_connecting(xprt)) |
941 | return; |
942 | /* Race breaker */ |
943 | if (!xprt_connected(xprt)) { |
944 | xprt->stat.connect_start = jiffies; |
945 | xprt->ops->connect(xprt, task); |
946 | } else { |
947 | xprt_clear_connecting(xprt); |
948 | task->tk_status = 0; |
949 | rpc_wake_up_queued_task(&xprt->pending, task); |
950 | } |
951 | } |
952 | xprt_release_write(xprt, task); |
953 | } |
954 | |
955 | /** |
956 | * xprt_reconnect_delay - compute the wait before scheduling a connect |
957 | * @xprt: transport instance |
958 | * |
959 | */ |
960 | unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt) |
961 | { |
962 | unsigned long start, now = jiffies; |
963 | |
964 | start = xprt->stat.connect_start + xprt->reestablish_timeout; |
965 | if (time_after(start, now)) |
966 | return start - now; |
967 | return 0; |
968 | } |
969 | EXPORT_SYMBOL_GPL(xprt_reconnect_delay); |
970 | |
971 | /** |
972 | * xprt_reconnect_backoff - compute the new re-establish timeout |
973 | * @xprt: transport instance |
974 | * @init_to: initial reestablish timeout |
975 | * |
976 | */ |
977 | void xprt_reconnect_backoff(struct rpc_xprt *xprt, unsigned long init_to) |
978 | { |
979 | xprt->reestablish_timeout <<= 1; |
980 | if (xprt->reestablish_timeout > xprt->max_reconnect_timeout) |
981 | xprt->reestablish_timeout = xprt->max_reconnect_timeout; |
982 | if (xprt->reestablish_timeout < init_to) |
983 | xprt->reestablish_timeout = init_to; |
984 | } |
985 | EXPORT_SYMBOL_GPL(xprt_reconnect_backoff); |
986 | |
987 | enum xprt_xid_rb_cmp { |
988 | XID_RB_EQUAL, |
989 | XID_RB_LEFT, |
990 | XID_RB_RIGHT, |
991 | }; |
992 | static enum xprt_xid_rb_cmp |
993 | xprt_xid_cmp(__be32 xid1, __be32 xid2) |
994 | { |
995 | if (xid1 == xid2) |
996 | return XID_RB_EQUAL; |
997 | if ((__force u32)xid1 < (__force u32)xid2) |
998 | return XID_RB_LEFT; |
999 | return XID_RB_RIGHT; |
1000 | } |
1001 | |
1002 | static struct rpc_rqst * |
1003 | xprt_request_rb_find(struct rpc_xprt *xprt, __be32 xid) |
1004 | { |
1005 | struct rb_node *n = xprt->recv_queue.rb_node; |
1006 | struct rpc_rqst *req; |
1007 | |
1008 | while (n != NULL) { |
1009 | req = rb_entry(n, struct rpc_rqst, rq_recv); |
1010 | switch (xprt_xid_cmp(xid1: xid, xid2: req->rq_xid)) { |
1011 | case XID_RB_LEFT: |
1012 | n = n->rb_left; |
1013 | break; |
1014 | case XID_RB_RIGHT: |
1015 | n = n->rb_right; |
1016 | break; |
1017 | case XID_RB_EQUAL: |
1018 | return req; |
1019 | } |
1020 | } |
1021 | return NULL; |
1022 | } |
1023 | |
1024 | static void |
1025 | xprt_request_rb_insert(struct rpc_xprt *xprt, struct rpc_rqst *new) |
1026 | { |
1027 | struct rb_node **p = &xprt->recv_queue.rb_node; |
1028 | struct rb_node *n = NULL; |
1029 | struct rpc_rqst *req; |
1030 | |
1031 | while (*p != NULL) { |
1032 | n = *p; |
1033 | req = rb_entry(n, struct rpc_rqst, rq_recv); |
1034 | switch(xprt_xid_cmp(xid1: new->rq_xid, xid2: req->rq_xid)) { |
1035 | case XID_RB_LEFT: |
1036 | p = &n->rb_left; |
1037 | break; |
1038 | case XID_RB_RIGHT: |
1039 | p = &n->rb_right; |
1040 | break; |
1041 | case XID_RB_EQUAL: |
1042 | WARN_ON_ONCE(new != req); |
1043 | return; |
1044 | } |
1045 | } |
1046 | rb_link_node(node: &new->rq_recv, parent: n, rb_link: p); |
1047 | rb_insert_color(&new->rq_recv, &xprt->recv_queue); |
1048 | } |
1049 | |
1050 | static void |
1051 | xprt_request_rb_remove(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1052 | { |
1053 | rb_erase(&req->rq_recv, &xprt->recv_queue); |
1054 | } |
1055 | |
1056 | /** |
1057 | * xprt_lookup_rqst - find an RPC request corresponding to an XID |
1058 | * @xprt: transport on which the original request was transmitted |
1059 | * @xid: RPC XID of incoming reply |
1060 | * |
1061 | * Caller holds xprt->queue_lock. |
1062 | */ |
1063 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
1064 | { |
1065 | struct rpc_rqst *entry; |
1066 | |
1067 | entry = xprt_request_rb_find(xprt, xid); |
1068 | if (entry != NULL) { |
1069 | trace_xprt_lookup_rqst(xprt, xid, status: 0); |
1070 | entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime); |
1071 | return entry; |
1072 | } |
1073 | |
1074 | dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n" , |
1075 | ntohl(xid)); |
1076 | trace_xprt_lookup_rqst(xprt, xid, status: -ENOENT); |
1077 | xprt->stat.bad_xids++; |
1078 | return NULL; |
1079 | } |
1080 | EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
1081 | |
1082 | static bool |
1083 | xprt_is_pinned_rqst(struct rpc_rqst *req) |
1084 | { |
1085 | return atomic_read(v: &req->rq_pin) != 0; |
1086 | } |
1087 | |
1088 | /** |
1089 | * xprt_pin_rqst - Pin a request on the transport receive list |
1090 | * @req: Request to pin |
1091 | * |
1092 | * Caller must ensure this is atomic with the call to xprt_lookup_rqst() |
1093 | * so should be holding xprt->queue_lock. |
1094 | */ |
1095 | void xprt_pin_rqst(struct rpc_rqst *req) |
1096 | { |
1097 | atomic_inc(v: &req->rq_pin); |
1098 | } |
1099 | EXPORT_SYMBOL_GPL(xprt_pin_rqst); |
1100 | |
1101 | /** |
1102 | * xprt_unpin_rqst - Unpin a request on the transport receive list |
1103 | * @req: Request to pin |
1104 | * |
1105 | * Caller should be holding xprt->queue_lock. |
1106 | */ |
1107 | void xprt_unpin_rqst(struct rpc_rqst *req) |
1108 | { |
1109 | if (!test_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate)) { |
1110 | atomic_dec(v: &req->rq_pin); |
1111 | return; |
1112 | } |
1113 | if (atomic_dec_and_test(v: &req->rq_pin)) |
1114 | wake_up_var(var: &req->rq_pin); |
1115 | } |
1116 | EXPORT_SYMBOL_GPL(xprt_unpin_rqst); |
1117 | |
1118 | static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req) |
1119 | { |
1120 | wait_var_event(&req->rq_pin, !xprt_is_pinned_rqst(req)); |
1121 | } |
1122 | |
1123 | static bool |
1124 | xprt_request_data_received(struct rpc_task *task) |
1125 | { |
1126 | return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && |
1127 | READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) != 0; |
1128 | } |
1129 | |
1130 | static bool |
1131 | xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req) |
1132 | { |
1133 | return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && |
1134 | READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) == 0; |
1135 | } |
1136 | |
1137 | /** |
1138 | * xprt_request_enqueue_receive - Add an request to the receive queue |
1139 | * @task: RPC task |
1140 | * |
1141 | */ |
1142 | int |
1143 | xprt_request_enqueue_receive(struct rpc_task *task) |
1144 | { |
1145 | struct rpc_rqst *req = task->tk_rqstp; |
1146 | struct rpc_xprt *xprt = req->rq_xprt; |
1147 | int ret; |
1148 | |
1149 | if (!xprt_request_need_enqueue_receive(task, req)) |
1150 | return 0; |
1151 | |
1152 | ret = xprt_request_prepare(req: task->tk_rqstp, buf: &req->rq_rcv_buf); |
1153 | if (ret) |
1154 | return ret; |
1155 | spin_lock(lock: &xprt->queue_lock); |
1156 | |
1157 | /* Update the softirq receive buffer */ |
1158 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, |
1159 | sizeof(req->rq_private_buf)); |
1160 | |
1161 | /* Add request to the receive list */ |
1162 | xprt_request_rb_insert(xprt, new: req); |
1163 | set_bit(RPC_TASK_NEED_RECV, addr: &task->tk_runstate); |
1164 | spin_unlock(lock: &xprt->queue_lock); |
1165 | |
1166 | /* Turn off autodisconnect */ |
1167 | del_timer_sync(timer: &xprt->timer); |
1168 | return 0; |
1169 | } |
1170 | |
1171 | /** |
1172 | * xprt_request_dequeue_receive_locked - Remove a request from the receive queue |
1173 | * @task: RPC task |
1174 | * |
1175 | * Caller must hold xprt->queue_lock. |
1176 | */ |
1177 | static void |
1178 | xprt_request_dequeue_receive_locked(struct rpc_task *task) |
1179 | { |
1180 | struct rpc_rqst *req = task->tk_rqstp; |
1181 | |
1182 | if (test_and_clear_bit(RPC_TASK_NEED_RECV, addr: &task->tk_runstate)) |
1183 | xprt_request_rb_remove(xprt: req->rq_xprt, req); |
1184 | } |
1185 | |
1186 | /** |
1187 | * xprt_update_rtt - Update RPC RTT statistics |
1188 | * @task: RPC request that recently completed |
1189 | * |
1190 | * Caller holds xprt->queue_lock. |
1191 | */ |
1192 | void xprt_update_rtt(struct rpc_task *task) |
1193 | { |
1194 | struct rpc_rqst *req = task->tk_rqstp; |
1195 | struct rpc_rtt *rtt = task->tk_client->cl_rtt; |
1196 | unsigned int timer = task->tk_msg.rpc_proc->p_timer; |
1197 | long m = usecs_to_jiffies(u: ktime_to_us(kt: req->rq_rtt)); |
1198 | |
1199 | if (timer) { |
1200 | if (req->rq_ntrans == 1) |
1201 | rpc_update_rtt(rt: rtt, timer, m); |
1202 | rpc_set_timeo(rt: rtt, timer, ntimeo: req->rq_ntrans - 1); |
1203 | } |
1204 | } |
1205 | EXPORT_SYMBOL_GPL(xprt_update_rtt); |
1206 | |
1207 | /** |
1208 | * xprt_complete_rqst - called when reply processing is complete |
1209 | * @task: RPC request that recently completed |
1210 | * @copied: actual number of bytes received from the transport |
1211 | * |
1212 | * Caller holds xprt->queue_lock. |
1213 | */ |
1214 | void xprt_complete_rqst(struct rpc_task *task, int copied) |
1215 | { |
1216 | struct rpc_rqst *req = task->tk_rqstp; |
1217 | struct rpc_xprt *xprt = req->rq_xprt; |
1218 | |
1219 | xprt->stat.recvs++; |
1220 | |
1221 | xdr_free_bvec(buf: &req->rq_rcv_buf); |
1222 | req->rq_private_buf.bvec = NULL; |
1223 | req->rq_private_buf.len = copied; |
1224 | /* Ensure all writes are done before we update */ |
1225 | /* req->rq_reply_bytes_recvd */ |
1226 | smp_wmb(); |
1227 | req->rq_reply_bytes_recvd = copied; |
1228 | xprt_request_dequeue_receive_locked(task); |
1229 | rpc_wake_up_queued_task(&xprt->pending, task); |
1230 | } |
1231 | EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
1232 | |
1233 | static void xprt_timer(struct rpc_task *task) |
1234 | { |
1235 | struct rpc_rqst *req = task->tk_rqstp; |
1236 | struct rpc_xprt *xprt = req->rq_xprt; |
1237 | |
1238 | if (task->tk_status != -ETIMEDOUT) |
1239 | return; |
1240 | |
1241 | trace_xprt_timer(xprt, xid: req->rq_xid, status: task->tk_status); |
1242 | if (!req->rq_reply_bytes_recvd) { |
1243 | if (xprt->ops->timer) |
1244 | xprt->ops->timer(xprt, task); |
1245 | } else |
1246 | task->tk_status = 0; |
1247 | } |
1248 | |
1249 | /** |
1250 | * xprt_wait_for_reply_request_def - wait for reply |
1251 | * @task: pointer to rpc_task |
1252 | * |
1253 | * Set a request's retransmit timeout based on the transport's |
1254 | * default timeout parameters. Used by transports that don't adjust |
1255 | * the retransmit timeout based on round-trip time estimation, |
1256 | * and put the task to sleep on the pending queue. |
1257 | */ |
1258 | void xprt_wait_for_reply_request_def(struct rpc_task *task) |
1259 | { |
1260 | struct rpc_rqst *req = task->tk_rqstp; |
1261 | |
1262 | rpc_sleep_on_timeout(queue: &req->rq_xprt->pending, task, action: xprt_timer, |
1263 | timeout: xprt_request_timeout(req)); |
1264 | } |
1265 | EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_def); |
1266 | |
1267 | /** |
1268 | * xprt_wait_for_reply_request_rtt - wait for reply using RTT estimator |
1269 | * @task: pointer to rpc_task |
1270 | * |
1271 | * Set a request's retransmit timeout using the RTT estimator, |
1272 | * and put the task to sleep on the pending queue. |
1273 | */ |
1274 | void xprt_wait_for_reply_request_rtt(struct rpc_task *task) |
1275 | { |
1276 | int timer = task->tk_msg.rpc_proc->p_timer; |
1277 | struct rpc_clnt *clnt = task->tk_client; |
1278 | struct rpc_rtt *rtt = clnt->cl_rtt; |
1279 | struct rpc_rqst *req = task->tk_rqstp; |
1280 | unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
1281 | unsigned long timeout; |
1282 | |
1283 | timeout = rpc_calc_rto(rt: rtt, timer); |
1284 | timeout <<= rpc_ntimeo(rt: rtt, timer) + req->rq_retries; |
1285 | if (timeout > max_timeout || timeout == 0) |
1286 | timeout = max_timeout; |
1287 | rpc_sleep_on_timeout(queue: &req->rq_xprt->pending, task, action: xprt_timer, |
1288 | timeout: jiffies + timeout); |
1289 | } |
1290 | EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_rtt); |
1291 | |
1292 | /** |
1293 | * xprt_request_wait_receive - wait for the reply to an RPC request |
1294 | * @task: RPC task about to send a request |
1295 | * |
1296 | */ |
1297 | void xprt_request_wait_receive(struct rpc_task *task) |
1298 | { |
1299 | struct rpc_rqst *req = task->tk_rqstp; |
1300 | struct rpc_xprt *xprt = req->rq_xprt; |
1301 | |
1302 | if (!test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) |
1303 | return; |
1304 | /* |
1305 | * Sleep on the pending queue if we're expecting a reply. |
1306 | * The spinlock ensures atomicity between the test of |
1307 | * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on(). |
1308 | */ |
1309 | spin_lock(lock: &xprt->queue_lock); |
1310 | if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) { |
1311 | xprt->ops->wait_for_reply_request(task); |
1312 | /* |
1313 | * Send an extra queue wakeup call if the |
1314 | * connection was dropped in case the call to |
1315 | * rpc_sleep_on() raced. |
1316 | */ |
1317 | if (xprt_request_retransmit_after_disconnect(task)) |
1318 | rpc_wake_up_queued_task_set_status(&xprt->pending, |
1319 | task, -ENOTCONN); |
1320 | } |
1321 | spin_unlock(lock: &xprt->queue_lock); |
1322 | } |
1323 | |
1324 | static bool |
1325 | xprt_request_need_enqueue_transmit(struct rpc_task *task, struct rpc_rqst *req) |
1326 | { |
1327 | return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate); |
1328 | } |
1329 | |
1330 | /** |
1331 | * xprt_request_enqueue_transmit - queue a task for transmission |
1332 | * @task: pointer to rpc_task |
1333 | * |
1334 | * Add a task to the transmission queue. |
1335 | */ |
1336 | void |
1337 | xprt_request_enqueue_transmit(struct rpc_task *task) |
1338 | { |
1339 | struct rpc_rqst *pos, *req = task->tk_rqstp; |
1340 | struct rpc_xprt *xprt = req->rq_xprt; |
1341 | int ret; |
1342 | |
1343 | if (xprt_request_need_enqueue_transmit(task, req)) { |
1344 | ret = xprt_request_prepare(req: task->tk_rqstp, buf: &req->rq_snd_buf); |
1345 | if (ret) { |
1346 | task->tk_status = ret; |
1347 | return; |
1348 | } |
1349 | req->rq_bytes_sent = 0; |
1350 | spin_lock(lock: &xprt->queue_lock); |
1351 | /* |
1352 | * Requests that carry congestion control credits are added |
1353 | * to the head of the list to avoid starvation issues. |
1354 | */ |
1355 | if (req->rq_cong) { |
1356 | xprt_clear_congestion_window_wait(xprt); |
1357 | list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { |
1358 | if (pos->rq_cong) |
1359 | continue; |
1360 | /* Note: req is added _before_ pos */ |
1361 | list_add_tail(new: &req->rq_xmit, head: &pos->rq_xmit); |
1362 | INIT_LIST_HEAD(list: &req->rq_xmit2); |
1363 | goto out; |
1364 | } |
1365 | } else if (!req->rq_seqno) { |
1366 | list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { |
1367 | if (pos->rq_task->tk_owner != task->tk_owner) |
1368 | continue; |
1369 | list_add_tail(new: &req->rq_xmit2, head: &pos->rq_xmit2); |
1370 | INIT_LIST_HEAD(list: &req->rq_xmit); |
1371 | goto out; |
1372 | } |
1373 | } |
1374 | list_add_tail(new: &req->rq_xmit, head: &xprt->xmit_queue); |
1375 | INIT_LIST_HEAD(list: &req->rq_xmit2); |
1376 | out: |
1377 | atomic_long_inc(v: &xprt->xmit_queuelen); |
1378 | set_bit(RPC_TASK_NEED_XMIT, addr: &task->tk_runstate); |
1379 | spin_unlock(lock: &xprt->queue_lock); |
1380 | } |
1381 | } |
1382 | |
1383 | /** |
1384 | * xprt_request_dequeue_transmit_locked - remove a task from the transmission queue |
1385 | * @task: pointer to rpc_task |
1386 | * |
1387 | * Remove a task from the transmission queue |
1388 | * Caller must hold xprt->queue_lock |
1389 | */ |
1390 | static void |
1391 | xprt_request_dequeue_transmit_locked(struct rpc_task *task) |
1392 | { |
1393 | struct rpc_rqst *req = task->tk_rqstp; |
1394 | |
1395 | if (!test_and_clear_bit(RPC_TASK_NEED_XMIT, addr: &task->tk_runstate)) |
1396 | return; |
1397 | if (!list_empty(head: &req->rq_xmit)) { |
1398 | list_del(entry: &req->rq_xmit); |
1399 | if (!list_empty(head: &req->rq_xmit2)) { |
1400 | struct rpc_rqst *next = list_first_entry(&req->rq_xmit2, |
1401 | struct rpc_rqst, rq_xmit2); |
1402 | list_del(entry: &req->rq_xmit2); |
1403 | list_add_tail(new: &next->rq_xmit, head: &next->rq_xprt->xmit_queue); |
1404 | } |
1405 | } else |
1406 | list_del(entry: &req->rq_xmit2); |
1407 | atomic_long_dec(v: &req->rq_xprt->xmit_queuelen); |
1408 | xdr_free_bvec(buf: &req->rq_snd_buf); |
1409 | } |
1410 | |
1411 | /** |
1412 | * xprt_request_dequeue_transmit - remove a task from the transmission queue |
1413 | * @task: pointer to rpc_task |
1414 | * |
1415 | * Remove a task from the transmission queue |
1416 | */ |
1417 | static void |
1418 | xprt_request_dequeue_transmit(struct rpc_task *task) |
1419 | { |
1420 | struct rpc_rqst *req = task->tk_rqstp; |
1421 | struct rpc_xprt *xprt = req->rq_xprt; |
1422 | |
1423 | spin_lock(lock: &xprt->queue_lock); |
1424 | xprt_request_dequeue_transmit_locked(task); |
1425 | spin_unlock(lock: &xprt->queue_lock); |
1426 | } |
1427 | |
1428 | /** |
1429 | * xprt_request_dequeue_xprt - remove a task from the transmit+receive queue |
1430 | * @task: pointer to rpc_task |
1431 | * |
1432 | * Remove a task from the transmit and receive queues, and ensure that |
1433 | * it is not pinned by the receive work item. |
1434 | */ |
1435 | void |
1436 | xprt_request_dequeue_xprt(struct rpc_task *task) |
1437 | { |
1438 | struct rpc_rqst *req = task->tk_rqstp; |
1439 | struct rpc_xprt *xprt = req->rq_xprt; |
1440 | |
1441 | if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) || |
1442 | test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) || |
1443 | xprt_is_pinned_rqst(req)) { |
1444 | spin_lock(lock: &xprt->queue_lock); |
1445 | while (xprt_is_pinned_rqst(req)) { |
1446 | set_bit(RPC_TASK_MSG_PIN_WAIT, addr: &task->tk_runstate); |
1447 | spin_unlock(lock: &xprt->queue_lock); |
1448 | xprt_wait_on_pinned_rqst(req); |
1449 | spin_lock(lock: &xprt->queue_lock); |
1450 | clear_bit(RPC_TASK_MSG_PIN_WAIT, addr: &task->tk_runstate); |
1451 | } |
1452 | xprt_request_dequeue_transmit_locked(task); |
1453 | xprt_request_dequeue_receive_locked(task); |
1454 | spin_unlock(lock: &xprt->queue_lock); |
1455 | xdr_free_bvec(buf: &req->rq_rcv_buf); |
1456 | } |
1457 | } |
1458 | |
1459 | /** |
1460 | * xprt_request_prepare - prepare an encoded request for transport |
1461 | * @req: pointer to rpc_rqst |
1462 | * @buf: pointer to send/rcv xdr_buf |
1463 | * |
1464 | * Calls into the transport layer to do whatever is needed to prepare |
1465 | * the request for transmission or receive. |
1466 | * Returns error, or zero. |
1467 | */ |
1468 | static int |
1469 | xprt_request_prepare(struct rpc_rqst *req, struct xdr_buf *buf) |
1470 | { |
1471 | struct rpc_xprt *xprt = req->rq_xprt; |
1472 | |
1473 | if (xprt->ops->prepare_request) |
1474 | return xprt->ops->prepare_request(req, buf); |
1475 | return 0; |
1476 | } |
1477 | |
1478 | /** |
1479 | * xprt_request_need_retransmit - Test if a task needs retransmission |
1480 | * @task: pointer to rpc_task |
1481 | * |
1482 | * Test for whether a connection breakage requires the task to retransmit |
1483 | */ |
1484 | bool |
1485 | xprt_request_need_retransmit(struct rpc_task *task) |
1486 | { |
1487 | return xprt_request_retransmit_after_disconnect(task); |
1488 | } |
1489 | |
1490 | /** |
1491 | * xprt_prepare_transmit - reserve the transport before sending a request |
1492 | * @task: RPC task about to send a request |
1493 | * |
1494 | */ |
1495 | bool xprt_prepare_transmit(struct rpc_task *task) |
1496 | { |
1497 | struct rpc_rqst *req = task->tk_rqstp; |
1498 | struct rpc_xprt *xprt = req->rq_xprt; |
1499 | |
1500 | if (!xprt_lock_write(xprt, task)) { |
1501 | /* Race breaker: someone may have transmitted us */ |
1502 | if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
1503 | rpc_wake_up_queued_task_set_status(&xprt->sending, |
1504 | task, 0); |
1505 | return false; |
1506 | |
1507 | } |
1508 | if (atomic_read(v: &xprt->swapper)) |
1509 | /* This will be clear in __rpc_execute */ |
1510 | current->flags |= PF_MEMALLOC; |
1511 | return true; |
1512 | } |
1513 | |
1514 | void xprt_end_transmit(struct rpc_task *task) |
1515 | { |
1516 | struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
1517 | |
1518 | xprt_inject_disconnect(xprt); |
1519 | xprt_release_write(xprt, task); |
1520 | } |
1521 | |
1522 | /** |
1523 | * xprt_request_transmit - send an RPC request on a transport |
1524 | * @req: pointer to request to transmit |
1525 | * @snd_task: RPC task that owns the transport lock |
1526 | * |
1527 | * This performs the transmission of a single request. |
1528 | * Note that if the request is not the same as snd_task, then it |
1529 | * does need to be pinned. |
1530 | * Returns '0' on success. |
1531 | */ |
1532 | static int |
1533 | xprt_request_transmit(struct rpc_rqst *req, struct rpc_task *snd_task) |
1534 | { |
1535 | struct rpc_xprt *xprt = req->rq_xprt; |
1536 | struct rpc_task *task = req->rq_task; |
1537 | unsigned int connect_cookie; |
1538 | int is_retrans = RPC_WAS_SENT(task); |
1539 | int status; |
1540 | |
1541 | if (!req->rq_bytes_sent) { |
1542 | if (xprt_request_data_received(task)) { |
1543 | status = 0; |
1544 | goto out_dequeue; |
1545 | } |
1546 | /* Verify that our message lies in the RPCSEC_GSS window */ |
1547 | if (rpcauth_xmit_need_reencode(task)) { |
1548 | status = -EBADMSG; |
1549 | goto out_dequeue; |
1550 | } |
1551 | if (RPC_SIGNALLED(task)) { |
1552 | status = -ERESTARTSYS; |
1553 | goto out_dequeue; |
1554 | } |
1555 | } |
1556 | |
1557 | /* |
1558 | * Update req->rq_ntrans before transmitting to avoid races with |
1559 | * xprt_update_rtt(), which needs to know that it is recording a |
1560 | * reply to the first transmission. |
1561 | */ |
1562 | req->rq_ntrans++; |
1563 | |
1564 | trace_rpc_xdr_sendto(task, xdr: &req->rq_snd_buf); |
1565 | connect_cookie = xprt->connect_cookie; |
1566 | status = xprt->ops->send_request(req); |
1567 | if (status != 0) { |
1568 | req->rq_ntrans--; |
1569 | trace_xprt_transmit(rqst: req, status); |
1570 | return status; |
1571 | } |
1572 | |
1573 | if (is_retrans) { |
1574 | task->tk_client->cl_stats->rpcretrans++; |
1575 | trace_xprt_retransmit(rqst: req); |
1576 | } |
1577 | |
1578 | xprt_inject_disconnect(xprt); |
1579 | |
1580 | task->tk_flags |= RPC_TASK_SENT; |
1581 | spin_lock(lock: &xprt->transport_lock); |
1582 | |
1583 | xprt->stat.sends++; |
1584 | xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; |
1585 | xprt->stat.bklog_u += xprt->backlog.qlen; |
1586 | xprt->stat.sending_u += xprt->sending.qlen; |
1587 | xprt->stat.pending_u += xprt->pending.qlen; |
1588 | spin_unlock(lock: &xprt->transport_lock); |
1589 | |
1590 | req->rq_connect_cookie = connect_cookie; |
1591 | out_dequeue: |
1592 | trace_xprt_transmit(rqst: req, status); |
1593 | xprt_request_dequeue_transmit(task); |
1594 | rpc_wake_up_queued_task_set_status(&xprt->sending, task, status); |
1595 | return status; |
1596 | } |
1597 | |
1598 | /** |
1599 | * xprt_transmit - send an RPC request on a transport |
1600 | * @task: controlling RPC task |
1601 | * |
1602 | * Attempts to drain the transmit queue. On exit, either the transport |
1603 | * signalled an error that needs to be handled before transmission can |
1604 | * resume, or @task finished transmitting, and detected that it already |
1605 | * received a reply. |
1606 | */ |
1607 | void |
1608 | xprt_transmit(struct rpc_task *task) |
1609 | { |
1610 | struct rpc_rqst *next, *req = task->tk_rqstp; |
1611 | struct rpc_xprt *xprt = req->rq_xprt; |
1612 | int status; |
1613 | |
1614 | spin_lock(lock: &xprt->queue_lock); |
1615 | for (;;) { |
1616 | next = list_first_entry_or_null(&xprt->xmit_queue, |
1617 | struct rpc_rqst, rq_xmit); |
1618 | if (!next) |
1619 | break; |
1620 | xprt_pin_rqst(next); |
1621 | spin_unlock(lock: &xprt->queue_lock); |
1622 | status = xprt_request_transmit(req: next, snd_task: task); |
1623 | if (status == -EBADMSG && next != req) |
1624 | status = 0; |
1625 | spin_lock(lock: &xprt->queue_lock); |
1626 | xprt_unpin_rqst(next); |
1627 | if (status < 0) { |
1628 | if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
1629 | task->tk_status = status; |
1630 | break; |
1631 | } |
1632 | /* Was @task transmitted, and has it received a reply? */ |
1633 | if (xprt_request_data_received(task) && |
1634 | !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
1635 | break; |
1636 | cond_resched_lock(&xprt->queue_lock); |
1637 | } |
1638 | spin_unlock(lock: &xprt->queue_lock); |
1639 | } |
1640 | |
1641 | static void xprt_complete_request_init(struct rpc_task *task) |
1642 | { |
1643 | if (task->tk_rqstp) |
1644 | xprt_request_init(task); |
1645 | } |
1646 | |
1647 | void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) |
1648 | { |
1649 | set_bit(XPRT_CONGESTED, addr: &xprt->state); |
1650 | rpc_sleep_on(&xprt->backlog, task, action: xprt_complete_request_init); |
1651 | } |
1652 | EXPORT_SYMBOL_GPL(xprt_add_backlog); |
1653 | |
1654 | static bool __xprt_set_rq(struct rpc_task *task, void *data) |
1655 | { |
1656 | struct rpc_rqst *req = data; |
1657 | |
1658 | if (task->tk_rqstp == NULL) { |
1659 | memset(req, 0, sizeof(*req)); /* mark unused */ |
1660 | task->tk_rqstp = req; |
1661 | return true; |
1662 | } |
1663 | return false; |
1664 | } |
1665 | |
1666 | bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1667 | { |
1668 | if (rpc_wake_up_first(&xprt->backlog, __xprt_set_rq, req) == NULL) { |
1669 | clear_bit(XPRT_CONGESTED, addr: &xprt->state); |
1670 | return false; |
1671 | } |
1672 | return true; |
1673 | } |
1674 | EXPORT_SYMBOL_GPL(xprt_wake_up_backlog); |
1675 | |
1676 | static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) |
1677 | { |
1678 | bool ret = false; |
1679 | |
1680 | if (!test_bit(XPRT_CONGESTED, &xprt->state)) |
1681 | goto out; |
1682 | spin_lock(lock: &xprt->reserve_lock); |
1683 | if (test_bit(XPRT_CONGESTED, &xprt->state)) { |
1684 | xprt_add_backlog(xprt, task); |
1685 | ret = true; |
1686 | } |
1687 | spin_unlock(lock: &xprt->reserve_lock); |
1688 | out: |
1689 | return ret; |
1690 | } |
1691 | |
1692 | static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt) |
1693 | { |
1694 | struct rpc_rqst *req = ERR_PTR(error: -EAGAIN); |
1695 | |
1696 | if (xprt->num_reqs >= xprt->max_reqs) |
1697 | goto out; |
1698 | ++xprt->num_reqs; |
1699 | spin_unlock(lock: &xprt->reserve_lock); |
1700 | req = kzalloc(size: sizeof(*req), flags: rpc_task_gfp_mask()); |
1701 | spin_lock(lock: &xprt->reserve_lock); |
1702 | if (req != NULL) |
1703 | goto out; |
1704 | --xprt->num_reqs; |
1705 | req = ERR_PTR(error: -ENOMEM); |
1706 | out: |
1707 | return req; |
1708 | } |
1709 | |
1710 | static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1711 | { |
1712 | if (xprt->num_reqs > xprt->min_reqs) { |
1713 | --xprt->num_reqs; |
1714 | kfree(objp: req); |
1715 | return true; |
1716 | } |
1717 | return false; |
1718 | } |
1719 | |
1720 | void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) |
1721 | { |
1722 | struct rpc_rqst *req; |
1723 | |
1724 | spin_lock(lock: &xprt->reserve_lock); |
1725 | if (!list_empty(head: &xprt->free)) { |
1726 | req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
1727 | list_del(entry: &req->rq_list); |
1728 | goto out_init_req; |
1729 | } |
1730 | req = xprt_dynamic_alloc_slot(xprt); |
1731 | if (!IS_ERR(ptr: req)) |
1732 | goto out_init_req; |
1733 | switch (PTR_ERR(ptr: req)) { |
1734 | case -ENOMEM: |
1735 | dprintk("RPC: dynamic allocation of request slot " |
1736 | "failed! Retrying\n" ); |
1737 | task->tk_status = -ENOMEM; |
1738 | break; |
1739 | case -EAGAIN: |
1740 | xprt_add_backlog(xprt, task); |
1741 | dprintk("RPC: waiting for request slot\n" ); |
1742 | fallthrough; |
1743 | default: |
1744 | task->tk_status = -EAGAIN; |
1745 | } |
1746 | spin_unlock(lock: &xprt->reserve_lock); |
1747 | return; |
1748 | out_init_req: |
1749 | xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots, |
1750 | xprt->num_reqs); |
1751 | spin_unlock(lock: &xprt->reserve_lock); |
1752 | |
1753 | task->tk_status = 0; |
1754 | task->tk_rqstp = req; |
1755 | } |
1756 | EXPORT_SYMBOL_GPL(xprt_alloc_slot); |
1757 | |
1758 | void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1759 | { |
1760 | spin_lock(lock: &xprt->reserve_lock); |
1761 | if (!xprt_wake_up_backlog(xprt, req) && |
1762 | !xprt_dynamic_free_slot(xprt, req)) { |
1763 | memset(req, 0, sizeof(*req)); /* mark unused */ |
1764 | list_add(new: &req->rq_list, head: &xprt->free); |
1765 | } |
1766 | spin_unlock(lock: &xprt->reserve_lock); |
1767 | } |
1768 | EXPORT_SYMBOL_GPL(xprt_free_slot); |
1769 | |
1770 | static void xprt_free_all_slots(struct rpc_xprt *xprt) |
1771 | { |
1772 | struct rpc_rqst *req; |
1773 | while (!list_empty(head: &xprt->free)) { |
1774 | req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); |
1775 | list_del(entry: &req->rq_list); |
1776 | kfree(objp: req); |
1777 | } |
1778 | } |
1779 | |
1780 | static DEFINE_IDA(rpc_xprt_ids); |
1781 | |
1782 | void xprt_cleanup_ids(void) |
1783 | { |
1784 | ida_destroy(ida: &rpc_xprt_ids); |
1785 | } |
1786 | |
1787 | static int xprt_alloc_id(struct rpc_xprt *xprt) |
1788 | { |
1789 | int id; |
1790 | |
1791 | id = ida_alloc(ida: &rpc_xprt_ids, GFP_KERNEL); |
1792 | if (id < 0) |
1793 | return id; |
1794 | |
1795 | xprt->id = id; |
1796 | return 0; |
1797 | } |
1798 | |
1799 | static void xprt_free_id(struct rpc_xprt *xprt) |
1800 | { |
1801 | ida_free(&rpc_xprt_ids, id: xprt->id); |
1802 | } |
1803 | |
1804 | struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
1805 | unsigned int num_prealloc, |
1806 | unsigned int max_alloc) |
1807 | { |
1808 | struct rpc_xprt *xprt; |
1809 | struct rpc_rqst *req; |
1810 | int i; |
1811 | |
1812 | xprt = kzalloc(size, GFP_KERNEL); |
1813 | if (xprt == NULL) |
1814 | goto out; |
1815 | |
1816 | xprt_alloc_id(xprt); |
1817 | xprt_init(xprt, net); |
1818 | |
1819 | for (i = 0; i < num_prealloc; i++) { |
1820 | req = kzalloc(size: sizeof(struct rpc_rqst), GFP_KERNEL); |
1821 | if (!req) |
1822 | goto out_free; |
1823 | list_add(new: &req->rq_list, head: &xprt->free); |
1824 | } |
1825 | xprt->max_reqs = max_t(unsigned int, max_alloc, num_prealloc); |
1826 | xprt->min_reqs = num_prealloc; |
1827 | xprt->num_reqs = num_prealloc; |
1828 | |
1829 | return xprt; |
1830 | |
1831 | out_free: |
1832 | xprt_free(xprt); |
1833 | out: |
1834 | return NULL; |
1835 | } |
1836 | EXPORT_SYMBOL_GPL(xprt_alloc); |
1837 | |
1838 | void xprt_free(struct rpc_xprt *xprt) |
1839 | { |
1840 | put_net_track(net: xprt->xprt_net, tracker: &xprt->ns_tracker); |
1841 | xprt_free_all_slots(xprt); |
1842 | xprt_free_id(xprt); |
1843 | rpc_sysfs_xprt_destroy(xprt); |
1844 | kfree_rcu(xprt, rcu); |
1845 | } |
1846 | EXPORT_SYMBOL_GPL(xprt_free); |
1847 | |
1848 | static void |
1849 | xprt_init_connect_cookie(struct rpc_rqst *req, struct rpc_xprt *xprt) |
1850 | { |
1851 | req->rq_connect_cookie = xprt_connect_cookie(xprt) - 1; |
1852 | } |
1853 | |
1854 | static __be32 |
1855 | xprt_alloc_xid(struct rpc_xprt *xprt) |
1856 | { |
1857 | __be32 xid; |
1858 | |
1859 | spin_lock(lock: &xprt->reserve_lock); |
1860 | xid = (__force __be32)xprt->xid++; |
1861 | spin_unlock(lock: &xprt->reserve_lock); |
1862 | return xid; |
1863 | } |
1864 | |
1865 | static void |
1866 | xprt_init_xid(struct rpc_xprt *xprt) |
1867 | { |
1868 | xprt->xid = get_random_u32(); |
1869 | } |
1870 | |
1871 | static void |
1872 | xprt_request_init(struct rpc_task *task) |
1873 | { |
1874 | struct rpc_xprt *xprt = task->tk_xprt; |
1875 | struct rpc_rqst *req = task->tk_rqstp; |
1876 | |
1877 | req->rq_task = task; |
1878 | req->rq_xprt = xprt; |
1879 | req->rq_buffer = NULL; |
1880 | req->rq_xid = xprt_alloc_xid(xprt); |
1881 | xprt_init_connect_cookie(req, xprt); |
1882 | req->rq_snd_buf.len = 0; |
1883 | req->rq_snd_buf.buflen = 0; |
1884 | req->rq_rcv_buf.len = 0; |
1885 | req->rq_rcv_buf.buflen = 0; |
1886 | req->rq_snd_buf.bvec = NULL; |
1887 | req->rq_rcv_buf.bvec = NULL; |
1888 | req->rq_release_snd_buf = NULL; |
1889 | xprt_init_majortimeo(task, req); |
1890 | |
1891 | trace_xprt_reserve(rqst: req); |
1892 | } |
1893 | |
1894 | static void |
1895 | xprt_do_reserve(struct rpc_xprt *xprt, struct rpc_task *task) |
1896 | { |
1897 | xprt->ops->alloc_slot(xprt, task); |
1898 | if (task->tk_rqstp != NULL) |
1899 | xprt_request_init(task); |
1900 | } |
1901 | |
1902 | /** |
1903 | * xprt_reserve - allocate an RPC request slot |
1904 | * @task: RPC task requesting a slot allocation |
1905 | * |
1906 | * If the transport is marked as being congested, or if no more |
1907 | * slots are available, place the task on the transport's |
1908 | * backlog queue. |
1909 | */ |
1910 | void xprt_reserve(struct rpc_task *task) |
1911 | { |
1912 | struct rpc_xprt *xprt = task->tk_xprt; |
1913 | |
1914 | task->tk_status = 0; |
1915 | if (task->tk_rqstp != NULL) |
1916 | return; |
1917 | |
1918 | task->tk_status = -EAGAIN; |
1919 | if (!xprt_throttle_congested(xprt, task)) |
1920 | xprt_do_reserve(xprt, task); |
1921 | } |
1922 | |
1923 | /** |
1924 | * xprt_retry_reserve - allocate an RPC request slot |
1925 | * @task: RPC task requesting a slot allocation |
1926 | * |
1927 | * If no more slots are available, place the task on the transport's |
1928 | * backlog queue. |
1929 | * Note that the only difference with xprt_reserve is that we now |
1930 | * ignore the value of the XPRT_CONGESTED flag. |
1931 | */ |
1932 | void xprt_retry_reserve(struct rpc_task *task) |
1933 | { |
1934 | struct rpc_xprt *xprt = task->tk_xprt; |
1935 | |
1936 | task->tk_status = 0; |
1937 | if (task->tk_rqstp != NULL) |
1938 | return; |
1939 | |
1940 | task->tk_status = -EAGAIN; |
1941 | xprt_do_reserve(xprt, task); |
1942 | } |
1943 | |
1944 | /** |
1945 | * xprt_release - release an RPC request slot |
1946 | * @task: task which is finished with the slot |
1947 | * |
1948 | */ |
1949 | void xprt_release(struct rpc_task *task) |
1950 | { |
1951 | struct rpc_xprt *xprt; |
1952 | struct rpc_rqst *req = task->tk_rqstp; |
1953 | |
1954 | if (req == NULL) { |
1955 | if (task->tk_client) { |
1956 | xprt = task->tk_xprt; |
1957 | xprt_release_write(xprt, task); |
1958 | } |
1959 | return; |
1960 | } |
1961 | |
1962 | xprt = req->rq_xprt; |
1963 | xprt_request_dequeue_xprt(task); |
1964 | spin_lock(lock: &xprt->transport_lock); |
1965 | xprt->ops->release_xprt(xprt, task); |
1966 | if (xprt->ops->release_request) |
1967 | xprt->ops->release_request(task); |
1968 | xprt_schedule_autodisconnect(xprt); |
1969 | spin_unlock(lock: &xprt->transport_lock); |
1970 | if (req->rq_buffer) |
1971 | xprt->ops->buf_free(task); |
1972 | if (req->rq_cred != NULL) |
1973 | put_rpccred(req->rq_cred); |
1974 | if (req->rq_release_snd_buf) |
1975 | req->rq_release_snd_buf(req); |
1976 | |
1977 | task->tk_rqstp = NULL; |
1978 | if (likely(!bc_prealloc(req))) |
1979 | xprt->ops->free_slot(xprt, req); |
1980 | else |
1981 | xprt_free_bc_request(req); |
1982 | } |
1983 | |
1984 | #ifdef CONFIG_SUNRPC_BACKCHANNEL |
1985 | void |
1986 | xprt_init_bc_request(struct rpc_rqst *req, struct rpc_task *task) |
1987 | { |
1988 | struct xdr_buf *xbufp = &req->rq_snd_buf; |
1989 | |
1990 | task->tk_rqstp = req; |
1991 | req->rq_task = task; |
1992 | xprt_init_connect_cookie(req, xprt: req->rq_xprt); |
1993 | /* |
1994 | * Set up the xdr_buf length. |
1995 | * This also indicates that the buffer is XDR encoded already. |
1996 | */ |
1997 | xbufp->len = xbufp->head[0].iov_len + xbufp->page_len + |
1998 | xbufp->tail[0].iov_len; |
1999 | } |
2000 | #endif |
2001 | |
2002 | static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
2003 | { |
2004 | kref_init(kref: &xprt->kref); |
2005 | |
2006 | spin_lock_init(&xprt->transport_lock); |
2007 | spin_lock_init(&xprt->reserve_lock); |
2008 | spin_lock_init(&xprt->queue_lock); |
2009 | |
2010 | INIT_LIST_HEAD(list: &xprt->free); |
2011 | xprt->recv_queue = RB_ROOT; |
2012 | INIT_LIST_HEAD(list: &xprt->xmit_queue); |
2013 | #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
2014 | spin_lock_init(&xprt->bc_pa_lock); |
2015 | INIT_LIST_HEAD(list: &xprt->bc_pa_list); |
2016 | #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
2017 | INIT_LIST_HEAD(list: &xprt->xprt_switch); |
2018 | |
2019 | xprt->last_used = jiffies; |
2020 | xprt->cwnd = RPC_INITCWND; |
2021 | xprt->bind_index = 0; |
2022 | |
2023 | rpc_init_wait_queue(&xprt->binding, "xprt_binding" ); |
2024 | rpc_init_wait_queue(&xprt->pending, "xprt_pending" ); |
2025 | rpc_init_wait_queue(&xprt->sending, "xprt_sending" ); |
2026 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog" ); |
2027 | |
2028 | xprt_init_xid(xprt); |
2029 | |
2030 | xprt->xprt_net = get_net_track(net, tracker: &xprt->ns_tracker, GFP_KERNEL); |
2031 | } |
2032 | |
2033 | /** |
2034 | * xprt_create_transport - create an RPC transport |
2035 | * @args: rpc transport creation arguments |
2036 | * |
2037 | */ |
2038 | struct rpc_xprt *xprt_create_transport(struct xprt_create *args) |
2039 | { |
2040 | struct rpc_xprt *xprt; |
2041 | const struct xprt_class *t; |
2042 | |
2043 | t = xprt_class_find_by_ident(ident: args->ident); |
2044 | if (!t) { |
2045 | dprintk("RPC: transport (%d) not supported\n" , args->ident); |
2046 | return ERR_PTR(error: -EIO); |
2047 | } |
2048 | |
2049 | xprt = t->setup(args); |
2050 | xprt_class_release(t); |
2051 | |
2052 | if (IS_ERR(ptr: xprt)) |
2053 | goto out; |
2054 | if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT) |
2055 | xprt->idle_timeout = 0; |
2056 | INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
2057 | if (xprt_has_timer(xprt)) |
2058 | timer_setup(&xprt->timer, xprt_init_autodisconnect, 0); |
2059 | else |
2060 | timer_setup(&xprt->timer, NULL, 0); |
2061 | |
2062 | if (strlen(args->servername) > RPC_MAXNETNAMELEN) { |
2063 | xprt_destroy(xprt); |
2064 | return ERR_PTR(error: -EINVAL); |
2065 | } |
2066 | xprt->servername = kstrdup(s: args->servername, GFP_KERNEL); |
2067 | if (xprt->servername == NULL) { |
2068 | xprt_destroy(xprt); |
2069 | return ERR_PTR(error: -ENOMEM); |
2070 | } |
2071 | |
2072 | rpc_xprt_debugfs_register(xprt); |
2073 | |
2074 | trace_xprt_create(xprt); |
2075 | out: |
2076 | return xprt; |
2077 | } |
2078 | |
2079 | static void xprt_destroy_cb(struct work_struct *work) |
2080 | { |
2081 | struct rpc_xprt *xprt = |
2082 | container_of(work, struct rpc_xprt, task_cleanup); |
2083 | |
2084 | trace_xprt_destroy(xprt); |
2085 | |
2086 | rpc_xprt_debugfs_unregister(xprt); |
2087 | rpc_destroy_wait_queue(&xprt->binding); |
2088 | rpc_destroy_wait_queue(&xprt->pending); |
2089 | rpc_destroy_wait_queue(&xprt->sending); |
2090 | rpc_destroy_wait_queue(&xprt->backlog); |
2091 | kfree(objp: xprt->servername); |
2092 | /* |
2093 | * Destroy any existing back channel |
2094 | */ |
2095 | xprt_destroy_backchannel(xprt, UINT_MAX); |
2096 | |
2097 | /* |
2098 | * Tear down transport state and free the rpc_xprt |
2099 | */ |
2100 | xprt->ops->destroy(xprt); |
2101 | } |
2102 | |
2103 | /** |
2104 | * xprt_destroy - destroy an RPC transport, killing off all requests. |
2105 | * @xprt: transport to destroy |
2106 | * |
2107 | */ |
2108 | static void xprt_destroy(struct rpc_xprt *xprt) |
2109 | { |
2110 | /* |
2111 | * Exclude transport connect/disconnect handlers and autoclose |
2112 | */ |
2113 | wait_on_bit_lock(word: &xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); |
2114 | |
2115 | /* |
2116 | * xprt_schedule_autodisconnect() can run after XPRT_LOCKED |
2117 | * is cleared. We use ->transport_lock to ensure the mod_timer() |
2118 | * can only run *before* del_time_sync(), never after. |
2119 | */ |
2120 | spin_lock(lock: &xprt->transport_lock); |
2121 | del_timer_sync(timer: &xprt->timer); |
2122 | spin_unlock(lock: &xprt->transport_lock); |
2123 | |
2124 | /* |
2125 | * Destroy sockets etc from the system workqueue so they can |
2126 | * safely flush receive work running on rpciod. |
2127 | */ |
2128 | INIT_WORK(&xprt->task_cleanup, xprt_destroy_cb); |
2129 | schedule_work(work: &xprt->task_cleanup); |
2130 | } |
2131 | |
2132 | static void xprt_destroy_kref(struct kref *kref) |
2133 | { |
2134 | xprt_destroy(container_of(kref, struct rpc_xprt, kref)); |
2135 | } |
2136 | |
2137 | /** |
2138 | * xprt_get - return a reference to an RPC transport. |
2139 | * @xprt: pointer to the transport |
2140 | * |
2141 | */ |
2142 | struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) |
2143 | { |
2144 | if (xprt != NULL && kref_get_unless_zero(kref: &xprt->kref)) |
2145 | return xprt; |
2146 | return NULL; |
2147 | } |
2148 | EXPORT_SYMBOL_GPL(xprt_get); |
2149 | |
2150 | /** |
2151 | * xprt_put - release a reference to an RPC transport. |
2152 | * @xprt: pointer to the transport |
2153 | * |
2154 | */ |
2155 | void xprt_put(struct rpc_xprt *xprt) |
2156 | { |
2157 | if (xprt != NULL) |
2158 | kref_put(kref: &xprt->kref, release: xprt_destroy_kref); |
2159 | } |
2160 | EXPORT_SYMBOL_GPL(xprt_put); |
2161 | |
2162 | void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps) |
2163 | { |
2164 | if (!test_and_set_bit(XPRT_OFFLINE, addr: &xprt->state)) { |
2165 | spin_lock(lock: &xps->xps_lock); |
2166 | xps->xps_nactive--; |
2167 | spin_unlock(lock: &xps->xps_lock); |
2168 | } |
2169 | } |
2170 | |
2171 | void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps) |
2172 | { |
2173 | if (test_and_clear_bit(XPRT_OFFLINE, addr: &xprt->state)) { |
2174 | spin_lock(lock: &xps->xps_lock); |
2175 | xps->xps_nactive++; |
2176 | spin_unlock(lock: &xps->xps_lock); |
2177 | } |
2178 | } |
2179 | |
2180 | void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps) |
2181 | { |
2182 | if (test_and_set_bit(XPRT_REMOVE, addr: &xprt->state)) |
2183 | return; |
2184 | |
2185 | xprt_force_disconnect(xprt); |
2186 | if (!test_bit(XPRT_CONNECTED, &xprt->state)) |
2187 | return; |
2188 | |
2189 | if (!xprt->sending.qlen && !xprt->pending.qlen && |
2190 | !xprt->backlog.qlen && !atomic_long_read(v: &xprt->queuelen)) |
2191 | rpc_xprt_switch_remove_xprt(xps, xprt, offline: true); |
2192 | } |
2193 | |