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 */
72static void xprt_init(struct rpc_xprt *xprt, struct net *net);
73static __be32 xprt_alloc_xid(struct rpc_xprt *xprt);
74static void xprt_destroy(struct rpc_xprt *xprt);
75static void xprt_request_init(struct rpc_task *task);
76static int xprt_request_prepare(struct rpc_rqst *req, struct xdr_buf *buf);
77
78static DEFINE_SPINLOCK(xprt_list_lock);
79static LIST_HEAD(xprt_list);
80
81static 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 */
102int 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
120out:
121 spin_unlock(lock: &xprt_list_lock);
122 return result;
123}
124EXPORT_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 */
134int 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
152out:
153 spin_unlock(lock: &xprt_list_lock);
154 return result;
155}
156EXPORT_SYMBOL_GPL(xprt_unregister_transport);
157
158static void
159xprt_class_release(const struct xprt_class *t)
160{
161 module_put(module: t->owner);
162}
163
164static const struct xprt_class *
165xprt_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
179static const struct xprt_class *
180xprt_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
190static const struct xprt_class *
191xprt_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
208static const struct xprt_class *
209xprt_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 */
233int 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}
245EXPORT_SYMBOL_GPL(xprt_find_transport_ident);
246
247static 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 */
265int 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
278out_locked:
279 trace_xprt_reserve_xprt(xprt, task);
280 return 1;
281
282out_unlock:
283 xprt_clear_locked(xprt);
284out_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}
293EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
294
295static bool
296xprt_need_congestion_window_wait(struct rpc_xprt *xprt)
297{
298 return test_bit(XPRT_CWND_WAIT, &xprt->state);
299}
300
301static void
302xprt_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
313static void
314xprt_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 */
329int 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 }
348out_unlock:
349 xprt_clear_locked(xprt);
350out_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;
358out_locked:
359 trace_xprt_reserve_cong(xprt, task);
360 return 1;
361}
362EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
363
364static 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
376static 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
384static 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;
393out_unlock:
394 xprt_clear_locked(xprt);
395}
396
397static 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;
408out_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 */
419void 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}
427EXPORT_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 */
437void 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}
445EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
446
447void 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 */
460static 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 */
479static 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 */
498bool
499xprt_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}
510EXPORT_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 */
518void 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}
524EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
525
526static 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 */
536static void
537xprt_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 */
562void 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}
584EXPORT_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 */
592void 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}
599EXPORT_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 */
609void xprt_wait_for_buffer_space(struct rpc_xprt *xprt)
610{
611 set_bit(XPRT_WRITE_SPACE, addr: &xprt->state);
612}
613EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
614
615static bool
616xprt_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 */
633bool 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}
644EXPORT_SYMBOL_GPL(xprt_write_space);
645
646static 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
654static unsigned long xprt_calc_majortimeo(struct rpc_rqst *req,
655 const struct rpc_timeout *to)
656{
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
668static void xprt_reset_majortimeo(struct rpc_rqst *req,
669 const struct rpc_timeout *to)
670{
671 req->rq_majortimeo += xprt_calc_majortimeo(req, to);
672}
673
674static void xprt_reset_minortimeo(struct rpc_rqst *req)
675{
676 req->rq_minortimeo += req->rq_timeout;
677}
678
679static void xprt_init_majortimeo(struct rpc_task *task, struct rpc_rqst *req,
680 const struct rpc_timeout *to)
681{
682 unsigned long time_init;
683 struct rpc_xprt *xprt = req->rq_xprt;
684
685 if (likely(xprt && xprt_connected(xprt)))
686 time_init = jiffies;
687 else
688 time_init = xprt_abs_ktime_to_jiffies(abstime: task->tk_start);
689
690 req->rq_timeout = to->to_initval;
691 req->rq_majortimeo = time_init + xprt_calc_majortimeo(req, to);
692 req->rq_minortimeo = time_init + req->rq_timeout;
693}
694
695/**
696 * xprt_adjust_timeout - adjust timeout values for next retransmit
697 * @req: RPC request containing parameters to use for the adjustment
698 *
699 */
700int xprt_adjust_timeout(struct rpc_rqst *req)
701{
702 struct rpc_xprt *xprt = req->rq_xprt;
703 const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
704 int status = 0;
705
706 if (time_before(jiffies, req->rq_majortimeo)) {
707 if (time_before(jiffies, req->rq_minortimeo))
708 return status;
709 if (to->to_exponential)
710 req->rq_timeout <<= 1;
711 else
712 req->rq_timeout += to->to_increment;
713 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
714 req->rq_timeout = to->to_maxval;
715 req->rq_retries++;
716 } else {
717 req->rq_timeout = to->to_initval;
718 req->rq_retries = 0;
719 xprt_reset_majortimeo(req, to);
720 /* Reset the RTT counters == "slow start" */
721 spin_lock(lock: &xprt->transport_lock);
722 rpc_init_rtt(rt: req->rq_task->tk_client->cl_rtt, timeo: to->to_initval);
723 spin_unlock(lock: &xprt->transport_lock);
724 status = -ETIMEDOUT;
725 }
726 xprt_reset_minortimeo(req);
727
728 if (req->rq_timeout == 0) {
729 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
730 req->rq_timeout = 5 * HZ;
731 }
732 return status;
733}
734
735static void xprt_autoclose(struct work_struct *work)
736{
737 struct rpc_xprt *xprt =
738 container_of(work, struct rpc_xprt, task_cleanup);
739 unsigned int pflags = memalloc_nofs_save();
740
741 trace_xprt_disconnect_auto(xprt);
742 xprt->connect_cookie++;
743 smp_mb__before_atomic();
744 clear_bit(XPRT_CLOSE_WAIT, addr: &xprt->state);
745 xprt->ops->close(xprt);
746 xprt_release_write(xprt, NULL);
747 wake_up_bit(word: &xprt->state, XPRT_LOCKED);
748 memalloc_nofs_restore(flags: pflags);
749}
750
751/**
752 * xprt_disconnect_done - mark a transport as disconnected
753 * @xprt: transport to flag for disconnect
754 *
755 */
756void xprt_disconnect_done(struct rpc_xprt *xprt)
757{
758 trace_xprt_disconnect_done(xprt);
759 spin_lock(lock: &xprt->transport_lock);
760 xprt_clear_connected(xprt);
761 xprt_clear_write_space_locked(xprt);
762 xprt_clear_congestion_window_wait_locked(xprt);
763 xprt_wake_pending_tasks(xprt, -ENOTCONN);
764 spin_unlock(lock: &xprt->transport_lock);
765}
766EXPORT_SYMBOL_GPL(xprt_disconnect_done);
767
768/**
769 * xprt_schedule_autoclose_locked - Try to schedule an autoclose RPC call
770 * @xprt: transport to disconnect
771 */
772static void xprt_schedule_autoclose_locked(struct rpc_xprt *xprt)
773{
774 if (test_and_set_bit(XPRT_CLOSE_WAIT, addr: &xprt->state))
775 return;
776 if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state) == 0)
777 queue_work(wq: xprtiod_workqueue, work: &xprt->task_cleanup);
778 else if (xprt->snd_task && !test_bit(XPRT_SND_IS_COOKIE, &xprt->state))
779 rpc_wake_up_queued_task_set_status(&xprt->pending,
780 xprt->snd_task, -ENOTCONN);
781}
782
783/**
784 * xprt_force_disconnect - force a transport to disconnect
785 * @xprt: transport to disconnect
786 *
787 */
788void xprt_force_disconnect(struct rpc_xprt *xprt)
789{
790 trace_xprt_disconnect_force(xprt);
791
792 /* Don't race with the test_bit() in xprt_clear_locked() */
793 spin_lock(lock: &xprt->transport_lock);
794 xprt_schedule_autoclose_locked(xprt);
795 spin_unlock(lock: &xprt->transport_lock);
796}
797EXPORT_SYMBOL_GPL(xprt_force_disconnect);
798
799static unsigned int
800xprt_connect_cookie(struct rpc_xprt *xprt)
801{
802 return READ_ONCE(xprt->connect_cookie);
803}
804
805static bool
806xprt_request_retransmit_after_disconnect(struct rpc_task *task)
807{
808 struct rpc_rqst *req = task->tk_rqstp;
809 struct rpc_xprt *xprt = req->rq_xprt;
810
811 return req->rq_connect_cookie != xprt_connect_cookie(xprt) ||
812 !xprt_connected(xprt);
813}
814
815/**
816 * xprt_conditional_disconnect - force a transport to disconnect
817 * @xprt: transport to disconnect
818 * @cookie: 'connection cookie'
819 *
820 * This attempts to break the connection if and only if 'cookie' matches
821 * the current transport 'connection cookie'. It ensures that we don't
822 * try to break the connection more than once when we need to retransmit
823 * a batch of RPC requests.
824 *
825 */
826void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
827{
828 /* Don't race with the test_bit() in xprt_clear_locked() */
829 spin_lock(lock: &xprt->transport_lock);
830 if (cookie != xprt->connect_cookie)
831 goto out;
832 if (test_bit(XPRT_CLOSING, &xprt->state))
833 goto out;
834 xprt_schedule_autoclose_locked(xprt);
835out:
836 spin_unlock(lock: &xprt->transport_lock);
837}
838
839static bool
840xprt_has_timer(const struct rpc_xprt *xprt)
841{
842 return xprt->idle_timeout != 0;
843}
844
845static void
846xprt_schedule_autodisconnect(struct rpc_xprt *xprt)
847 __must_hold(&xprt->transport_lock)
848{
849 xprt->last_used = jiffies;
850 if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt))
851 mod_timer(timer: &xprt->timer, expires: xprt->last_used + xprt->idle_timeout);
852}
853
854static void
855xprt_init_autodisconnect(struct timer_list *t)
856{
857 struct rpc_xprt *xprt = timer_container_of(xprt, t, timer);
858
859 if (!RB_EMPTY_ROOT(&xprt->recv_queue))
860 return;
861 /* Reset xprt->last_used to avoid connect/autodisconnect cycling */
862 xprt->last_used = jiffies;
863 if (test_and_set_bit(XPRT_LOCKED, addr: &xprt->state))
864 return;
865 queue_work(wq: xprtiod_workqueue, work: &xprt->task_cleanup);
866}
867
868#if IS_ENABLED(CONFIG_FAIL_SUNRPC)
869static void xprt_inject_disconnect(struct rpc_xprt *xprt)
870{
871 if (!fail_sunrpc.ignore_client_disconnect &&
872 should_fail(&fail_sunrpc.attr, 1))
873 xprt->ops->inject_disconnect(xprt);
874}
875#else
876static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
877{
878}
879#endif
880
881bool xprt_lock_connect(struct rpc_xprt *xprt,
882 struct rpc_task *task,
883 void *cookie)
884{
885 bool ret = false;
886
887 spin_lock(lock: &xprt->transport_lock);
888 if (!test_bit(XPRT_LOCKED, &xprt->state))
889 goto out;
890 if (xprt->snd_task != task)
891 goto out;
892 set_bit(XPRT_SND_IS_COOKIE, addr: &xprt->state);
893 xprt->snd_task = cookie;
894 ret = true;
895out:
896 spin_unlock(lock: &xprt->transport_lock);
897 return ret;
898}
899EXPORT_SYMBOL_GPL(xprt_lock_connect);
900
901void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie)
902{
903 spin_lock(lock: &xprt->transport_lock);
904 if (xprt->snd_task != cookie)
905 goto out;
906 if (!test_bit(XPRT_LOCKED, &xprt->state))
907 goto out;
908 xprt->snd_task =NULL;
909 clear_bit(XPRT_SND_IS_COOKIE, addr: &xprt->state);
910 xprt->ops->release_xprt(xprt, NULL);
911 xprt_schedule_autodisconnect(xprt);
912out:
913 spin_unlock(lock: &xprt->transport_lock);
914 wake_up_bit(word: &xprt->state, XPRT_LOCKED);
915}
916EXPORT_SYMBOL_GPL(xprt_unlock_connect);
917
918/**
919 * xprt_connect - schedule a transport connect operation
920 * @task: RPC task that is requesting the connect
921 *
922 */
923void xprt_connect(struct rpc_task *task)
924{
925 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
926
927 trace_xprt_connect(xprt);
928
929 if (!xprt_bound(xprt)) {
930 task->tk_status = -EAGAIN;
931 return;
932 }
933 if (!xprt_lock_write(xprt, task))
934 return;
935
936 if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
937 task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie;
938 rpc_sleep_on_timeout(queue: &xprt->pending, task, NULL,
939 timeout: xprt_request_timeout(req: task->tk_rqstp));
940
941 if (test_bit(XPRT_CLOSING, &xprt->state))
942 return;
943 if (xprt_test_and_set_connecting(xprt))
944 return;
945 /* Race breaker */
946 if (!xprt_connected(xprt)) {
947 xprt->stat.connect_start = jiffies;
948 xprt->ops->connect(xprt, task);
949 } else {
950 xprt_clear_connecting(xprt);
951 task->tk_status = 0;
952 rpc_wake_up_queued_task(&xprt->pending, task);
953 }
954 }
955 xprt_release_write(xprt, task);
956}
957
958/**
959 * xprt_reconnect_delay - compute the wait before scheduling a connect
960 * @xprt: transport instance
961 *
962 */
963unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt)
964{
965 unsigned long start, now = jiffies;
966
967 start = xprt->stat.connect_start + xprt->reestablish_timeout;
968 if (time_after(start, now))
969 return start - now;
970 return 0;
971}
972EXPORT_SYMBOL_GPL(xprt_reconnect_delay);
973
974/**
975 * xprt_reconnect_backoff - compute the new re-establish timeout
976 * @xprt: transport instance
977 * @init_to: initial reestablish timeout
978 *
979 */
980void xprt_reconnect_backoff(struct rpc_xprt *xprt, unsigned long init_to)
981{
982 xprt->reestablish_timeout <<= 1;
983 if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
984 xprt->reestablish_timeout = xprt->max_reconnect_timeout;
985 if (xprt->reestablish_timeout < init_to)
986 xprt->reestablish_timeout = init_to;
987}
988EXPORT_SYMBOL_GPL(xprt_reconnect_backoff);
989
990enum xprt_xid_rb_cmp {
991 XID_RB_EQUAL,
992 XID_RB_LEFT,
993 XID_RB_RIGHT,
994};
995static enum xprt_xid_rb_cmp
996xprt_xid_cmp(__be32 xid1, __be32 xid2)
997{
998 if (xid1 == xid2)
999 return XID_RB_EQUAL;
1000 if ((__force u32)xid1 < (__force u32)xid2)
1001 return XID_RB_LEFT;
1002 return XID_RB_RIGHT;
1003}
1004
1005static struct rpc_rqst *
1006xprt_request_rb_find(struct rpc_xprt *xprt, __be32 xid)
1007{
1008 struct rb_node *n = xprt->recv_queue.rb_node;
1009 struct rpc_rqst *req;
1010
1011 while (n != NULL) {
1012 req = rb_entry(n, struct rpc_rqst, rq_recv);
1013 switch (xprt_xid_cmp(xid1: xid, xid2: req->rq_xid)) {
1014 case XID_RB_LEFT:
1015 n = n->rb_left;
1016 break;
1017 case XID_RB_RIGHT:
1018 n = n->rb_right;
1019 break;
1020 case XID_RB_EQUAL:
1021 return req;
1022 }
1023 }
1024 return NULL;
1025}
1026
1027static void
1028xprt_request_rb_insert(struct rpc_xprt *xprt, struct rpc_rqst *new)
1029{
1030 struct rb_node **p = &xprt->recv_queue.rb_node;
1031 struct rb_node *n = NULL;
1032 struct rpc_rqst *req;
1033
1034 while (*p != NULL) {
1035 n = *p;
1036 req = rb_entry(n, struct rpc_rqst, rq_recv);
1037 switch(xprt_xid_cmp(xid1: new->rq_xid, xid2: req->rq_xid)) {
1038 case XID_RB_LEFT:
1039 p = &n->rb_left;
1040 break;
1041 case XID_RB_RIGHT:
1042 p = &n->rb_right;
1043 break;
1044 case XID_RB_EQUAL:
1045 WARN_ON_ONCE(new != req);
1046 return;
1047 }
1048 }
1049 rb_link_node(node: &new->rq_recv, parent: n, rb_link: p);
1050 rb_insert_color(&new->rq_recv, &xprt->recv_queue);
1051}
1052
1053static void
1054xprt_request_rb_remove(struct rpc_xprt *xprt, struct rpc_rqst *req)
1055{
1056 rb_erase(&req->rq_recv, &xprt->recv_queue);
1057}
1058
1059/**
1060 * xprt_lookup_rqst - find an RPC request corresponding to an XID
1061 * @xprt: transport on which the original request was transmitted
1062 * @xid: RPC XID of incoming reply
1063 *
1064 * Caller holds xprt->queue_lock.
1065 */
1066struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
1067{
1068 struct rpc_rqst *entry;
1069
1070 entry = xprt_request_rb_find(xprt, xid);
1071 if (entry != NULL) {
1072 trace_xprt_lookup_rqst(xprt, xid, status: 0);
1073 entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime);
1074 return entry;
1075 }
1076
1077 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
1078 ntohl(xid));
1079 trace_xprt_lookup_rqst(xprt, xid, status: -ENOENT);
1080 xprt->stat.bad_xids++;
1081 return NULL;
1082}
1083EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
1084
1085static bool
1086xprt_is_pinned_rqst(struct rpc_rqst *req)
1087{
1088 return atomic_read(v: &req->rq_pin) != 0;
1089}
1090
1091/**
1092 * xprt_pin_rqst - Pin a request on the transport receive list
1093 * @req: Request to pin
1094 *
1095 * Caller must ensure this is atomic with the call to xprt_lookup_rqst()
1096 * so should be holding xprt->queue_lock.
1097 */
1098void xprt_pin_rqst(struct rpc_rqst *req)
1099{
1100 atomic_inc(v: &req->rq_pin);
1101}
1102EXPORT_SYMBOL_GPL(xprt_pin_rqst);
1103
1104/**
1105 * xprt_unpin_rqst - Unpin a request on the transport receive list
1106 * @req: Request to pin
1107 *
1108 * Caller should be holding xprt->queue_lock.
1109 */
1110void xprt_unpin_rqst(struct rpc_rqst *req)
1111{
1112 if (!test_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate)) {
1113 atomic_dec(v: &req->rq_pin);
1114 return;
1115 }
1116 if (atomic_dec_and_test(v: &req->rq_pin))
1117 wake_up_var(var: &req->rq_pin);
1118}
1119EXPORT_SYMBOL_GPL(xprt_unpin_rqst);
1120
1121static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req)
1122{
1123 wait_var_event(&req->rq_pin, !xprt_is_pinned_rqst(req));
1124}
1125
1126static bool
1127xprt_request_data_received(struct rpc_task *task)
1128{
1129 return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) &&
1130 READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) != 0;
1131}
1132
1133static bool
1134xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req)
1135{
1136 return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) &&
1137 READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) == 0;
1138}
1139
1140/**
1141 * xprt_request_enqueue_receive - Add an request to the receive queue
1142 * @task: RPC task
1143 *
1144 */
1145int
1146xprt_request_enqueue_receive(struct rpc_task *task)
1147{
1148 struct rpc_rqst *req = task->tk_rqstp;
1149 struct rpc_xprt *xprt = req->rq_xprt;
1150 int ret;
1151
1152 if (!xprt_request_need_enqueue_receive(task, req))
1153 return 0;
1154
1155 ret = xprt_request_prepare(req: task->tk_rqstp, buf: &req->rq_rcv_buf);
1156 if (ret)
1157 return ret;
1158 spin_lock(lock: &xprt->queue_lock);
1159
1160 /* Update the softirq receive buffer */
1161 memcpy(to: &req->rq_private_buf, from: &req->rq_rcv_buf,
1162 len: sizeof(req->rq_private_buf));
1163
1164 /* Add request to the receive list */
1165 xprt_request_rb_insert(xprt, new: req);
1166 set_bit(nr: RPC_TASK_NEED_RECV, addr: &task->tk_runstate);
1167 spin_unlock(lock: &xprt->queue_lock);
1168
1169 /* Turn off autodisconnect */
1170 timer_delete_sync(timer: &xprt->timer);
1171 return 0;
1172}
1173
1174/**
1175 * xprt_request_dequeue_receive_locked - Remove a request from the receive queue
1176 * @task: RPC task
1177 *
1178 * Caller must hold xprt->queue_lock.
1179 */
1180static void
1181xprt_request_dequeue_receive_locked(struct rpc_task *task)
1182{
1183 struct rpc_rqst *req = task->tk_rqstp;
1184
1185 if (test_and_clear_bit(nr: RPC_TASK_NEED_RECV, addr: &task->tk_runstate))
1186 xprt_request_rb_remove(xprt: req->rq_xprt, req);
1187}
1188
1189/**
1190 * xprt_update_rtt - Update RPC RTT statistics
1191 * @task: RPC request that recently completed
1192 *
1193 * Caller holds xprt->queue_lock.
1194 */
1195void xprt_update_rtt(struct rpc_task *task)
1196{
1197 struct rpc_rqst *req = task->tk_rqstp;
1198 struct rpc_rtt *rtt = task->tk_client->cl_rtt;
1199 unsigned int timer = task->tk_msg.rpc_proc->p_timer;
1200 long m = usecs_to_jiffies(u: ktime_to_us(kt: req->rq_rtt));
1201
1202 if (timer) {
1203 if (req->rq_ntrans == 1)
1204 rpc_update_rtt(rt: rtt, timer, m);
1205 rpc_set_timeo(rt: rtt, timer, ntimeo: req->rq_ntrans - 1);
1206 }
1207}
1208EXPORT_SYMBOL_GPL(xprt_update_rtt);
1209
1210/**
1211 * xprt_complete_rqst - called when reply processing is complete
1212 * @task: RPC request that recently completed
1213 * @copied: actual number of bytes received from the transport
1214 *
1215 * Caller holds xprt->queue_lock.
1216 */
1217void xprt_complete_rqst(struct rpc_task *task, int copied)
1218{
1219 struct rpc_rqst *req = task->tk_rqstp;
1220 struct rpc_xprt *xprt = req->rq_xprt;
1221
1222 xprt->stat.recvs++;
1223
1224 xdr_free_bvec(buf: &req->rq_rcv_buf);
1225 req->rq_private_buf.bvec = NULL;
1226 req->rq_private_buf.len = copied;
1227 /* Ensure all writes are done before we update */
1228 /* req->rq_reply_bytes_recvd */
1229 smp_wmb();
1230 req->rq_reply_bytes_recvd = copied;
1231 xprt_request_dequeue_receive_locked(task);
1232 rpc_wake_up_queued_task(&xprt->pending, task);
1233}
1234EXPORT_SYMBOL_GPL(xprt_complete_rqst);
1235
1236static void xprt_timer(struct rpc_task *task)
1237{
1238 struct rpc_rqst *req = task->tk_rqstp;
1239 struct rpc_xprt *xprt = req->rq_xprt;
1240
1241 if (task->tk_status != -ETIMEDOUT)
1242 return;
1243
1244 trace_xprt_timer(xprt, xid: req->rq_xid, status: task->tk_status);
1245 if (!req->rq_reply_bytes_recvd) {
1246 if (xprt->ops->timer)
1247 xprt->ops->timer(xprt, task);
1248 } else
1249 task->tk_status = 0;
1250}
1251
1252/**
1253 * xprt_wait_for_reply_request_def - wait for reply
1254 * @task: pointer to rpc_task
1255 *
1256 * Set a request's retransmit timeout based on the transport's
1257 * default timeout parameters. Used by transports that don't adjust
1258 * the retransmit timeout based on round-trip time estimation,
1259 * and put the task to sleep on the pending queue.
1260 */
1261void xprt_wait_for_reply_request_def(struct rpc_task *task)
1262{
1263 struct rpc_rqst *req = task->tk_rqstp;
1264
1265 rpc_sleep_on_timeout(queue: &req->rq_xprt->pending, task, action: xprt_timer,
1266 timeout: xprt_request_timeout(req));
1267}
1268EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_def);
1269
1270/**
1271 * xprt_wait_for_reply_request_rtt - wait for reply using RTT estimator
1272 * @task: pointer to rpc_task
1273 *
1274 * Set a request's retransmit timeout using the RTT estimator,
1275 * and put the task to sleep on the pending queue.
1276 */
1277void xprt_wait_for_reply_request_rtt(struct rpc_task *task)
1278{
1279 int timer = task->tk_msg.rpc_proc->p_timer;
1280 struct rpc_clnt *clnt = task->tk_client;
1281 struct rpc_rtt *rtt = clnt->cl_rtt;
1282 struct rpc_rqst *req = task->tk_rqstp;
1283 unsigned long max_timeout = clnt->cl_timeout->to_maxval;
1284 unsigned long timeout;
1285
1286 timeout = rpc_calc_rto(rt: rtt, timer);
1287 timeout <<= rpc_ntimeo(rt: rtt, timer) + req->rq_retries;
1288 if (timeout > max_timeout || timeout == 0)
1289 timeout = max_timeout;
1290 rpc_sleep_on_timeout(queue: &req->rq_xprt->pending, task, action: xprt_timer,
1291 timeout: jiffies + timeout);
1292}
1293EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_rtt);
1294
1295/**
1296 * xprt_request_wait_receive - wait for the reply to an RPC request
1297 * @task: RPC task about to send a request
1298 *
1299 */
1300void xprt_request_wait_receive(struct rpc_task *task)
1301{
1302 struct rpc_rqst *req = task->tk_rqstp;
1303 struct rpc_xprt *xprt = req->rq_xprt;
1304
1305 if (!test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))
1306 return;
1307 /*
1308 * Sleep on the pending queue if we're expecting a reply.
1309 * The spinlock ensures atomicity between the test of
1310 * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on().
1311 */
1312 spin_lock(lock: &xprt->queue_lock);
1313 if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) {
1314 xprt->ops->wait_for_reply_request(task);
1315 /*
1316 * Send an extra queue wakeup call if the
1317 * connection was dropped in case the call to
1318 * rpc_sleep_on() raced.
1319 */
1320 if (xprt_request_retransmit_after_disconnect(task))
1321 rpc_wake_up_queued_task_set_status(&xprt->pending,
1322 task, -ENOTCONN);
1323 }
1324 spin_unlock(lock: &xprt->queue_lock);
1325}
1326
1327static bool
1328xprt_request_need_enqueue_transmit(struct rpc_task *task, struct rpc_rqst *req)
1329{
1330 return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1331}
1332
1333/**
1334 * xprt_request_enqueue_transmit - queue a task for transmission
1335 * @task: pointer to rpc_task
1336 *
1337 * Add a task to the transmission queue.
1338 */
1339void
1340xprt_request_enqueue_transmit(struct rpc_task *task)
1341{
1342 struct rpc_rqst *pos, *req = task->tk_rqstp;
1343 struct rpc_xprt *xprt = req->rq_xprt;
1344 int ret;
1345
1346 if (xprt_request_need_enqueue_transmit(task, req)) {
1347 ret = xprt_request_prepare(req: task->tk_rqstp, buf: &req->rq_snd_buf);
1348 if (ret) {
1349 task->tk_status = ret;
1350 return;
1351 }
1352 req->rq_bytes_sent = 0;
1353 spin_lock(lock: &xprt->queue_lock);
1354 /*
1355 * Requests that carry congestion control credits are added
1356 * to the head of the list to avoid starvation issues.
1357 */
1358 if (req->rq_cong) {
1359 xprt_clear_congestion_window_wait(xprt);
1360 list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) {
1361 if (pos->rq_cong)
1362 continue;
1363 /* Note: req is added _before_ pos */
1364 list_add_tail(new: &req->rq_xmit, head: &pos->rq_xmit);
1365 INIT_LIST_HEAD(list: &req->rq_xmit2);
1366 goto out;
1367 }
1368 } else if (req->rq_seqno_count == 0) {
1369 list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) {
1370 if (pos->rq_task->tk_owner != task->tk_owner)
1371 continue;
1372 list_add_tail(new: &req->rq_xmit2, head: &pos->rq_xmit2);
1373 INIT_LIST_HEAD(list: &req->rq_xmit);
1374 goto out;
1375 }
1376 }
1377 list_add_tail(new: &req->rq_xmit, head: &xprt->xmit_queue);
1378 INIT_LIST_HEAD(list: &req->rq_xmit2);
1379out:
1380 atomic_long_inc(v: &xprt->xmit_queuelen);
1381 set_bit(nr: RPC_TASK_NEED_XMIT, addr: &task->tk_runstate);
1382 spin_unlock(lock: &xprt->queue_lock);
1383 }
1384}
1385
1386/**
1387 * xprt_request_dequeue_transmit_locked - remove a task from the transmission queue
1388 * @task: pointer to rpc_task
1389 *
1390 * Remove a task from the transmission queue
1391 * Caller must hold xprt->queue_lock
1392 */
1393static void
1394xprt_request_dequeue_transmit_locked(struct rpc_task *task)
1395{
1396 struct rpc_rqst *req = task->tk_rqstp;
1397
1398 if (!test_and_clear_bit(nr: RPC_TASK_NEED_XMIT, addr: &task->tk_runstate))
1399 return;
1400 if (!list_empty(head: &req->rq_xmit)) {
1401 struct rpc_xprt *xprt = req->rq_xprt;
1402
1403 if (list_is_first(list: &req->rq_xmit, head: &xprt->xmit_queue) &&
1404 xprt->ops->abort_send_request)
1405 xprt->ops->abort_send_request(req);
1406
1407 list_del(entry: &req->rq_xmit);
1408 if (!list_empty(head: &req->rq_xmit2)) {
1409 struct rpc_rqst *next = list_first_entry(&req->rq_xmit2,
1410 struct rpc_rqst, rq_xmit2);
1411 list_del(entry: &req->rq_xmit2);
1412 list_add_tail(new: &next->rq_xmit, head: &next->rq_xprt->xmit_queue);
1413 }
1414 } else
1415 list_del(entry: &req->rq_xmit2);
1416 atomic_long_dec(v: &req->rq_xprt->xmit_queuelen);
1417 xdr_free_bvec(buf: &req->rq_snd_buf);
1418}
1419
1420/**
1421 * xprt_request_dequeue_transmit - remove a task from the transmission queue
1422 * @task: pointer to rpc_task
1423 *
1424 * Remove a task from the transmission queue
1425 */
1426static void
1427xprt_request_dequeue_transmit(struct rpc_task *task)
1428{
1429 struct rpc_rqst *req = task->tk_rqstp;
1430 struct rpc_xprt *xprt = req->rq_xprt;
1431
1432 spin_lock(lock: &xprt->queue_lock);
1433 xprt_request_dequeue_transmit_locked(task);
1434 spin_unlock(lock: &xprt->queue_lock);
1435}
1436
1437/**
1438 * xprt_request_dequeue_xprt - remove a task from the transmit+receive queue
1439 * @task: pointer to rpc_task
1440 *
1441 * Remove a task from the transmit and receive queues, and ensure that
1442 * it is not pinned by the receive work item.
1443 */
1444void
1445xprt_request_dequeue_xprt(struct rpc_task *task)
1446{
1447 struct rpc_rqst *req = task->tk_rqstp;
1448 struct rpc_xprt *xprt = req->rq_xprt;
1449
1450 if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) ||
1451 test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) ||
1452 xprt_is_pinned_rqst(req)) {
1453 spin_lock(lock: &xprt->queue_lock);
1454 while (xprt_is_pinned_rqst(req)) {
1455 set_bit(nr: RPC_TASK_MSG_PIN_WAIT, addr: &task->tk_runstate);
1456 spin_unlock(lock: &xprt->queue_lock);
1457 xprt_wait_on_pinned_rqst(req);
1458 spin_lock(lock: &xprt->queue_lock);
1459 clear_bit(nr: RPC_TASK_MSG_PIN_WAIT, addr: &task->tk_runstate);
1460 }
1461 xprt_request_dequeue_transmit_locked(task);
1462 xprt_request_dequeue_receive_locked(task);
1463 spin_unlock(lock: &xprt->queue_lock);
1464 xdr_free_bvec(buf: &req->rq_rcv_buf);
1465 }
1466}
1467
1468/**
1469 * xprt_request_prepare - prepare an encoded request for transport
1470 * @req: pointer to rpc_rqst
1471 * @buf: pointer to send/rcv xdr_buf
1472 *
1473 * Calls into the transport layer to do whatever is needed to prepare
1474 * the request for transmission or receive.
1475 * Returns error, or zero.
1476 */
1477static int
1478xprt_request_prepare(struct rpc_rqst *req, struct xdr_buf *buf)
1479{
1480 struct rpc_xprt *xprt = req->rq_xprt;
1481
1482 if (xprt->ops->prepare_request)
1483 return xprt->ops->prepare_request(req, buf);
1484 return 0;
1485}
1486
1487/**
1488 * xprt_request_need_retransmit - Test if a task needs retransmission
1489 * @task: pointer to rpc_task
1490 *
1491 * Test for whether a connection breakage requires the task to retransmit
1492 */
1493bool
1494xprt_request_need_retransmit(struct rpc_task *task)
1495{
1496 return xprt_request_retransmit_after_disconnect(task);
1497}
1498
1499/**
1500 * xprt_prepare_transmit - reserve the transport before sending a request
1501 * @task: RPC task about to send a request
1502 *
1503 */
1504bool xprt_prepare_transmit(struct rpc_task *task)
1505{
1506 struct rpc_rqst *req = task->tk_rqstp;
1507 struct rpc_xprt *xprt = req->rq_xprt;
1508
1509 if (!xprt_lock_write(xprt, task)) {
1510 /* Race breaker: someone may have transmitted us */
1511 if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
1512 rpc_wake_up_queued_task_set_status(&xprt->sending,
1513 task, 0);
1514 return false;
1515
1516 }
1517 if (atomic_read(v: &xprt->swapper))
1518 /* This will be clear in __rpc_execute */
1519 current->flags |= PF_MEMALLOC;
1520 return true;
1521}
1522
1523void xprt_end_transmit(struct rpc_task *task)
1524{
1525 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1526
1527 xprt_inject_disconnect(xprt);
1528 xprt_release_write(xprt, task);
1529}
1530
1531/**
1532 * xprt_request_transmit - send an RPC request on a transport
1533 * @req: pointer to request to transmit
1534 * @snd_task: RPC task that owns the transport lock
1535 *
1536 * This performs the transmission of a single request.
1537 * Note that if the request is not the same as snd_task, then it
1538 * does need to be pinned.
1539 * Returns '0' on success.
1540 */
1541static int
1542xprt_request_transmit(struct rpc_rqst *req, struct rpc_task *snd_task)
1543{
1544 struct rpc_xprt *xprt = req->rq_xprt;
1545 struct rpc_task *task = req->rq_task;
1546 unsigned int connect_cookie;
1547 int is_retrans = RPC_WAS_SENT(task);
1548 int status;
1549
1550 if (test_bit(XPRT_CLOSE_WAIT, &xprt->state))
1551 return -ENOTCONN;
1552
1553 if (!req->rq_bytes_sent) {
1554 if (xprt_request_data_received(task)) {
1555 status = 0;
1556 goto out_dequeue;
1557 }
1558 /* Verify that our message lies in the RPCSEC_GSS window */
1559 if (rpcauth_xmit_need_reencode(task)) {
1560 status = -EBADMSG;
1561 goto out_dequeue;
1562 }
1563 if (RPC_SIGNALLED(task)) {
1564 status = -ERESTARTSYS;
1565 goto out_dequeue;
1566 }
1567 }
1568
1569 /*
1570 * Update req->rq_ntrans before transmitting to avoid races with
1571 * xprt_update_rtt(), which needs to know that it is recording a
1572 * reply to the first transmission.
1573 */
1574 req->rq_ntrans++;
1575
1576 trace_rpc_xdr_sendto(task, xdr: &req->rq_snd_buf);
1577 connect_cookie = xprt->connect_cookie;
1578 status = xprt->ops->send_request(req);
1579 if (status != 0) {
1580 req->rq_ntrans--;
1581 trace_xprt_transmit(rqst: req, status);
1582 return status;
1583 }
1584
1585 if (is_retrans) {
1586 task->tk_client->cl_stats->rpcretrans++;
1587 trace_xprt_retransmit(rqst: req);
1588 }
1589
1590 xprt_inject_disconnect(xprt);
1591
1592 task->tk_flags |= RPC_TASK_SENT;
1593 spin_lock(lock: &xprt->transport_lock);
1594
1595 xprt->stat.sends++;
1596 xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
1597 xprt->stat.bklog_u += xprt->backlog.qlen;
1598 xprt->stat.sending_u += xprt->sending.qlen;
1599 xprt->stat.pending_u += xprt->pending.qlen;
1600 spin_unlock(lock: &xprt->transport_lock);
1601
1602 req->rq_connect_cookie = connect_cookie;
1603out_dequeue:
1604 trace_xprt_transmit(rqst: req, status);
1605 xprt_request_dequeue_transmit(task);
1606 rpc_wake_up_queued_task_set_status(&xprt->sending, task, status);
1607 return status;
1608}
1609
1610/**
1611 * xprt_transmit - send an RPC request on a transport
1612 * @task: controlling RPC task
1613 *
1614 * Attempts to drain the transmit queue. On exit, either the transport
1615 * signalled an error that needs to be handled before transmission can
1616 * resume, or @task finished transmitting, and detected that it already
1617 * received a reply.
1618 */
1619void
1620xprt_transmit(struct rpc_task *task)
1621{
1622 struct rpc_rqst *next, *req = task->tk_rqstp;
1623 struct rpc_xprt *xprt = req->rq_xprt;
1624 int status;
1625
1626 spin_lock(lock: &xprt->queue_lock);
1627 for (;;) {
1628 next = list_first_entry_or_null(&xprt->xmit_queue,
1629 struct rpc_rqst, rq_xmit);
1630 if (!next)
1631 break;
1632 xprt_pin_rqst(next);
1633 spin_unlock(lock: &xprt->queue_lock);
1634 status = xprt_request_transmit(req: next, snd_task: task);
1635 if (status == -EBADMSG && next != req)
1636 status = 0;
1637 spin_lock(lock: &xprt->queue_lock);
1638 xprt_unpin_rqst(next);
1639 if (status < 0) {
1640 if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
1641 task->tk_status = status;
1642 break;
1643 }
1644 /* Was @task transmitted, and has it received a reply? */
1645 if (xprt_request_data_received(task) &&
1646 !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
1647 break;
1648 cond_resched_lock(&xprt->queue_lock);
1649 }
1650 spin_unlock(lock: &xprt->queue_lock);
1651}
1652
1653static void xprt_complete_request_init(struct rpc_task *task)
1654{
1655 if (task->tk_rqstp)
1656 xprt_request_init(task);
1657}
1658
1659void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task)
1660{
1661 set_bit(XPRT_CONGESTED, addr: &xprt->state);
1662 rpc_sleep_on(&xprt->backlog, task, action: xprt_complete_request_init);
1663}
1664EXPORT_SYMBOL_GPL(xprt_add_backlog);
1665
1666static bool __xprt_set_rq(struct rpc_task *task, void *data)
1667{
1668 struct rpc_rqst *req = data;
1669
1670 if (task->tk_rqstp == NULL) {
1671 memset(s: req, c: 0, n: sizeof(*req)); /* mark unused */
1672 task->tk_rqstp = req;
1673 return true;
1674 }
1675 return false;
1676}
1677
1678bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req)
1679{
1680 if (rpc_wake_up_first(&xprt->backlog, __xprt_set_rq, req) == NULL) {
1681 clear_bit(XPRT_CONGESTED, addr: &xprt->state);
1682 return false;
1683 }
1684 return true;
1685}
1686EXPORT_SYMBOL_GPL(xprt_wake_up_backlog);
1687
1688static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task)
1689{
1690 bool ret = false;
1691
1692 if (!test_bit(XPRT_CONGESTED, &xprt->state))
1693 goto out;
1694 spin_lock(lock: &xprt->reserve_lock);
1695 if (test_bit(XPRT_CONGESTED, &xprt->state)) {
1696 xprt_add_backlog(xprt, task);
1697 ret = true;
1698 }
1699 spin_unlock(lock: &xprt->reserve_lock);
1700out:
1701 return ret;
1702}
1703
1704static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt)
1705{
1706 struct rpc_rqst *req = ERR_PTR(error: -EAGAIN);
1707
1708 if (xprt->num_reqs >= xprt->max_reqs)
1709 goto out;
1710 ++xprt->num_reqs;
1711 spin_unlock(lock: &xprt->reserve_lock);
1712 req = kzalloc(sizeof(*req), rpc_task_gfp_mask());
1713 spin_lock(lock: &xprt->reserve_lock);
1714 if (req != NULL)
1715 goto out;
1716 --xprt->num_reqs;
1717 req = ERR_PTR(error: -ENOMEM);
1718out:
1719 return req;
1720}
1721
1722static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1723{
1724 if (xprt->num_reqs > xprt->min_reqs) {
1725 --xprt->num_reqs;
1726 kfree(objp: req);
1727 return true;
1728 }
1729 return false;
1730}
1731
1732void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
1733{
1734 struct rpc_rqst *req;
1735
1736 spin_lock(lock: &xprt->reserve_lock);
1737 if (!list_empty(head: &xprt->free)) {
1738 req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1739 list_del(entry: &req->rq_list);
1740 goto out_init_req;
1741 }
1742 req = xprt_dynamic_alloc_slot(xprt);
1743 if (!IS_ERR(ptr: req))
1744 goto out_init_req;
1745 switch (PTR_ERR(ptr: req)) {
1746 case -ENOMEM:
1747 dprintk("RPC: dynamic allocation of request slot "
1748 "failed! Retrying\n");
1749 task->tk_status = -ENOMEM;
1750 break;
1751 case -EAGAIN:
1752 xprt_add_backlog(xprt, task);
1753 dprintk("RPC: waiting for request slot\n");
1754 fallthrough;
1755 default:
1756 task->tk_status = -EAGAIN;
1757 }
1758 spin_unlock(lock: &xprt->reserve_lock);
1759 return;
1760out_init_req:
1761 xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots,
1762 xprt->num_reqs);
1763 spin_unlock(lock: &xprt->reserve_lock);
1764
1765 task->tk_status = 0;
1766 task->tk_rqstp = req;
1767}
1768EXPORT_SYMBOL_GPL(xprt_alloc_slot);
1769
1770void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
1771{
1772 spin_lock(lock: &xprt->reserve_lock);
1773 if (!xprt_wake_up_backlog(xprt, req) &&
1774 !xprt_dynamic_free_slot(xprt, req)) {
1775 memset(s: req, c: 0, n: sizeof(*req)); /* mark unused */
1776 list_add(new: &req->rq_list, head: &xprt->free);
1777 }
1778 spin_unlock(lock: &xprt->reserve_lock);
1779}
1780EXPORT_SYMBOL_GPL(xprt_free_slot);
1781
1782static void xprt_free_all_slots(struct rpc_xprt *xprt)
1783{
1784 struct rpc_rqst *req;
1785 while (!list_empty(head: &xprt->free)) {
1786 req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list);
1787 list_del(entry: &req->rq_list);
1788 kfree(objp: req);
1789 }
1790}
1791
1792static DEFINE_IDA(rpc_xprt_ids);
1793
1794void xprt_cleanup_ids(void)
1795{
1796 ida_destroy(ida: &rpc_xprt_ids);
1797}
1798
1799static int xprt_alloc_id(struct rpc_xprt *xprt)
1800{
1801 int id;
1802
1803 id = ida_alloc(ida: &rpc_xprt_ids, GFP_KERNEL);
1804 if (id < 0)
1805 return id;
1806
1807 xprt->id = id;
1808 return 0;
1809}
1810
1811static void xprt_free_id(struct rpc_xprt *xprt)
1812{
1813 ida_free(&rpc_xprt_ids, id: xprt->id);
1814}
1815
1816struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
1817 unsigned int num_prealloc,
1818 unsigned int max_alloc)
1819{
1820 struct rpc_xprt *xprt;
1821 struct rpc_rqst *req;
1822 int i;
1823
1824 xprt = kzalloc(size, GFP_KERNEL);
1825 if (xprt == NULL)
1826 goto out;
1827
1828 xprt_alloc_id(xprt);
1829 xprt_init(xprt, net);
1830
1831 for (i = 0; i < num_prealloc; i++) {
1832 req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
1833 if (!req)
1834 goto out_free;
1835 list_add(new: &req->rq_list, head: &xprt->free);
1836 }
1837 xprt->max_reqs = max_t(unsigned int, max_alloc, num_prealloc);
1838 xprt->min_reqs = num_prealloc;
1839 xprt->num_reqs = num_prealloc;
1840
1841 return xprt;
1842
1843out_free:
1844 xprt_free(xprt);
1845out:
1846 return NULL;
1847}
1848EXPORT_SYMBOL_GPL(xprt_alloc);
1849
1850void xprt_free(struct rpc_xprt *xprt)
1851{
1852 put_net_track(net: xprt->xprt_net, tracker: &xprt->ns_tracker);
1853 xprt_free_all_slots(xprt);
1854 xprt_free_id(xprt);
1855 rpc_sysfs_xprt_destroy(xprt);
1856 kfree_rcu(xprt, rcu);
1857}
1858EXPORT_SYMBOL_GPL(xprt_free);
1859
1860static void
1861xprt_init_connect_cookie(struct rpc_rqst *req, struct rpc_xprt *xprt)
1862{
1863 req->rq_connect_cookie = xprt_connect_cookie(xprt) - 1;
1864}
1865
1866static __be32
1867xprt_alloc_xid(struct rpc_xprt *xprt)
1868{
1869 __be32 xid;
1870
1871 spin_lock(lock: &xprt->reserve_lock);
1872 xid = (__force __be32)xprt->xid++;
1873 spin_unlock(lock: &xprt->reserve_lock);
1874 return xid;
1875}
1876
1877static void
1878xprt_init_xid(struct rpc_xprt *xprt)
1879{
1880 xprt->xid = get_random_u32();
1881}
1882
1883static void
1884xprt_request_init(struct rpc_task *task)
1885{
1886 struct rpc_xprt *xprt = task->tk_xprt;
1887 struct rpc_rqst *req = task->tk_rqstp;
1888
1889 req->rq_task = task;
1890 req->rq_xprt = xprt;
1891 req->rq_buffer = NULL;
1892 req->rq_xid = xprt_alloc_xid(xprt);
1893 xprt_init_connect_cookie(req, xprt);
1894 req->rq_snd_buf.len = 0;
1895 req->rq_snd_buf.buflen = 0;
1896 req->rq_rcv_buf.len = 0;
1897 req->rq_rcv_buf.buflen = 0;
1898 req->rq_snd_buf.bvec = NULL;
1899 req->rq_rcv_buf.bvec = NULL;
1900 req->rq_release_snd_buf = NULL;
1901 req->rq_seqno_count = 0;
1902 xprt_init_majortimeo(task, req, to: task->tk_client->cl_timeout);
1903
1904 trace_xprt_reserve(rqst: req);
1905}
1906
1907static void
1908xprt_do_reserve(struct rpc_xprt *xprt, struct rpc_task *task)
1909{
1910 xprt->ops->alloc_slot(xprt, task);
1911 if (task->tk_rqstp != NULL)
1912 xprt_request_init(task);
1913}
1914
1915/**
1916 * xprt_reserve - allocate an RPC request slot
1917 * @task: RPC task requesting a slot allocation
1918 *
1919 * If the transport is marked as being congested, or if no more
1920 * slots are available, place the task on the transport's
1921 * backlog queue.
1922 */
1923void xprt_reserve(struct rpc_task *task)
1924{
1925 struct rpc_xprt *xprt = task->tk_xprt;
1926
1927 task->tk_status = 0;
1928 if (task->tk_rqstp != NULL)
1929 return;
1930
1931 task->tk_status = -EAGAIN;
1932 if (!xprt_throttle_congested(xprt, task))
1933 xprt_do_reserve(xprt, task);
1934}
1935
1936/**
1937 * xprt_retry_reserve - allocate an RPC request slot
1938 * @task: RPC task requesting a slot allocation
1939 *
1940 * If no more slots are available, place the task on the transport's
1941 * backlog queue.
1942 * Note that the only difference with xprt_reserve is that we now
1943 * ignore the value of the XPRT_CONGESTED flag.
1944 */
1945void xprt_retry_reserve(struct rpc_task *task)
1946{
1947 struct rpc_xprt *xprt = task->tk_xprt;
1948
1949 task->tk_status = 0;
1950 if (task->tk_rqstp != NULL)
1951 return;
1952
1953 task->tk_status = -EAGAIN;
1954 xprt_do_reserve(xprt, task);
1955}
1956
1957/**
1958 * xprt_release - release an RPC request slot
1959 * @task: task which is finished with the slot
1960 *
1961 */
1962void xprt_release(struct rpc_task *task)
1963{
1964 struct rpc_xprt *xprt;
1965 struct rpc_rqst *req = task->tk_rqstp;
1966
1967 if (req == NULL) {
1968 if (task->tk_client) {
1969 xprt = task->tk_xprt;
1970 xprt_release_write(xprt, task);
1971 }
1972 return;
1973 }
1974
1975 xprt = req->rq_xprt;
1976 xprt_request_dequeue_xprt(task);
1977 spin_lock(lock: &xprt->transport_lock);
1978 xprt->ops->release_xprt(xprt, task);
1979 if (xprt->ops->release_request)
1980 xprt->ops->release_request(task);
1981 xprt_schedule_autodisconnect(xprt);
1982 spin_unlock(lock: &xprt->transport_lock);
1983 if (req->rq_buffer)
1984 xprt->ops->buf_free(task);
1985 if (req->rq_cred != NULL)
1986 put_rpccred(req->rq_cred);
1987 if (req->rq_release_snd_buf)
1988 req->rq_release_snd_buf(req);
1989
1990 task->tk_rqstp = NULL;
1991 if (likely(!bc_prealloc(req)))
1992 xprt->ops->free_slot(xprt, req);
1993 else
1994 xprt_free_bc_request(req);
1995}
1996
1997#ifdef CONFIG_SUNRPC_BACKCHANNEL
1998void
1999xprt_init_bc_request(struct rpc_rqst *req, struct rpc_task *task,
2000 const struct rpc_timeout *to)
2001{
2002 struct xdr_buf *xbufp = &req->rq_snd_buf;
2003
2004 task->tk_rqstp = req;
2005 req->rq_task = task;
2006 xprt_init_connect_cookie(req, req->rq_xprt);
2007 /*
2008 * Set up the xdr_buf length.
2009 * This also indicates that the buffer is XDR encoded already.
2010 */
2011 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
2012 xbufp->tail[0].iov_len;
2013 /*
2014 * Backchannel Replies are sent with !RPC_TASK_SOFT and
2015 * RPC_TASK_NO_RETRANS_TIMEOUT. The major timeout setting
2016 * affects only how long each Reply waits to be sent when
2017 * a transport connection cannot be established.
2018 */
2019 xprt_init_majortimeo(task, req, to);
2020}
2021#endif
2022
2023static void xprt_init(struct rpc_xprt *xprt, struct net *net)
2024{
2025 kref_init(kref: &xprt->kref);
2026
2027 spin_lock_init(&xprt->transport_lock);
2028 spin_lock_init(&xprt->reserve_lock);
2029 spin_lock_init(&xprt->queue_lock);
2030
2031 INIT_LIST_HEAD(list: &xprt->free);
2032 xprt->recv_queue = RB_ROOT;
2033 INIT_LIST_HEAD(list: &xprt->xmit_queue);
2034#if defined(CONFIG_SUNRPC_BACKCHANNEL)
2035 spin_lock_init(&xprt->bc_pa_lock);
2036 INIT_LIST_HEAD(&xprt->bc_pa_list);
2037#endif /* CONFIG_SUNRPC_BACKCHANNEL */
2038 INIT_LIST_HEAD(list: &xprt->xprt_switch);
2039
2040 xprt->last_used = jiffies;
2041 xprt->cwnd = RPC_INITCWND;
2042 xprt->bind_index = 0;
2043
2044 rpc_init_wait_queue(&xprt->binding, "xprt_binding");
2045 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
2046 rpc_init_wait_queue(&xprt->sending, "xprt_sending");
2047 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
2048
2049 xprt_init_xid(xprt);
2050
2051 xprt->xprt_net = get_net_track(net, tracker: &xprt->ns_tracker, GFP_KERNEL);
2052}
2053
2054/**
2055 * xprt_create_transport - create an RPC transport
2056 * @args: rpc transport creation arguments
2057 *
2058 */
2059struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
2060{
2061 struct rpc_xprt *xprt;
2062 const struct xprt_class *t;
2063
2064 t = xprt_class_find_by_ident(ident: args->ident);
2065 if (!t) {
2066 dprintk("RPC: transport (%d) not supported\n", args->ident);
2067 return ERR_PTR(error: -EIO);
2068 }
2069
2070 xprt = t->setup(args);
2071 xprt_class_release(t);
2072
2073 if (IS_ERR(ptr: xprt))
2074 goto out;
2075 if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
2076 xprt->idle_timeout = 0;
2077 INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
2078 if (xprt_has_timer(xprt))
2079 timer_setup(&xprt->timer, xprt_init_autodisconnect, 0);
2080 else
2081 timer_setup(&xprt->timer, NULL, 0);
2082
2083 if (strlen(args->servername) > RPC_MAXNETNAMELEN) {
2084 xprt_destroy(xprt);
2085 return ERR_PTR(error: -EINVAL);
2086 }
2087 xprt->servername = kstrdup(s: args->servername, GFP_KERNEL);
2088 if (xprt->servername == NULL) {
2089 xprt_destroy(xprt);
2090 return ERR_PTR(error: -ENOMEM);
2091 }
2092
2093 rpc_xprt_debugfs_register(xprt);
2094
2095 trace_xprt_create(xprt);
2096out:
2097 return xprt;
2098}
2099
2100static void xprt_destroy_cb(struct work_struct *work)
2101{
2102 struct rpc_xprt *xprt =
2103 container_of(work, struct rpc_xprt, task_cleanup);
2104
2105 trace_xprt_destroy(xprt);
2106
2107 rpc_xprt_debugfs_unregister(xprt);
2108 rpc_destroy_wait_queue(&xprt->binding);
2109 rpc_destroy_wait_queue(&xprt->pending);
2110 rpc_destroy_wait_queue(&xprt->sending);
2111 rpc_destroy_wait_queue(&xprt->backlog);
2112 kfree(objp: xprt->servername);
2113 /*
2114 * Destroy any existing back channel
2115 */
2116 xprt_destroy_backchannel(xprt, UINT_MAX);
2117
2118 /*
2119 * Tear down transport state and free the rpc_xprt
2120 */
2121 xprt->ops->destroy(xprt);
2122}
2123
2124/**
2125 * xprt_destroy - destroy an RPC transport, killing off all requests.
2126 * @xprt: transport to destroy
2127 *
2128 */
2129static void xprt_destroy(struct rpc_xprt *xprt)
2130{
2131 /*
2132 * Exclude transport connect/disconnect handlers and autoclose
2133 */
2134 wait_on_bit_lock(word: &xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE);
2135
2136 /*
2137 * xprt_schedule_autodisconnect() can run after XPRT_LOCKED
2138 * is cleared. We use ->transport_lock to ensure the mod_timer()
2139 * can only run *before* del_time_sync(), never after.
2140 */
2141 spin_lock(lock: &xprt->transport_lock);
2142 timer_delete_sync(timer: &xprt->timer);
2143 spin_unlock(lock: &xprt->transport_lock);
2144
2145 /*
2146 * Destroy sockets etc from the system workqueue so they can
2147 * safely flush receive work running on rpciod.
2148 */
2149 INIT_WORK(&xprt->task_cleanup, xprt_destroy_cb);
2150 schedule_work(work: &xprt->task_cleanup);
2151}
2152
2153static void xprt_destroy_kref(struct kref *kref)
2154{
2155 xprt_destroy(container_of(kref, struct rpc_xprt, kref));
2156}
2157
2158/**
2159 * xprt_get - return a reference to an RPC transport.
2160 * @xprt: pointer to the transport
2161 *
2162 */
2163struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
2164{
2165 if (xprt != NULL && kref_get_unless_zero(kref: &xprt->kref))
2166 return xprt;
2167 return NULL;
2168}
2169EXPORT_SYMBOL_GPL(xprt_get);
2170
2171/**
2172 * xprt_put - release a reference to an RPC transport.
2173 * @xprt: pointer to the transport
2174 *
2175 */
2176void xprt_put(struct rpc_xprt *xprt)
2177{
2178 if (xprt != NULL)
2179 kref_put(kref: &xprt->kref, release: xprt_destroy_kref);
2180}
2181EXPORT_SYMBOL_GPL(xprt_put);
2182
2183void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps)
2184{
2185 if (!test_and_set_bit(XPRT_OFFLINE, addr: &xprt->state)) {
2186 spin_lock(lock: &xps->xps_lock);
2187 xps->xps_nactive--;
2188 spin_unlock(lock: &xps->xps_lock);
2189 }
2190}
2191
2192void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps)
2193{
2194 if (test_and_clear_bit(XPRT_OFFLINE, addr: &xprt->state)) {
2195 spin_lock(lock: &xps->xps_lock);
2196 xps->xps_nactive++;
2197 spin_unlock(lock: &xps->xps_lock);
2198 }
2199}
2200
2201void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps)
2202{
2203 if (test_and_set_bit(XPRT_REMOVE, addr: &xprt->state))
2204 return;
2205
2206 xprt_force_disconnect(xprt);
2207 if (!test_bit(XPRT_CONNECTED, &xprt->state))
2208 return;
2209
2210 if (!xprt->sending.qlen && !xprt->pending.qlen &&
2211 !xprt->backlog.qlen && !atomic_long_read(v: &xprt->queuelen))
2212 rpc_xprt_switch_remove_xprt(xps, xprt, offline: true);
2213}
2214