1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/net/sunrpc/xprt.c
5 * This is a generic RPC call interface supporting congestion avoidance,
6 * and asynchronous calls.
8 * The interface works like this:
10 * - When a process places a call, it allocates a request slot if
11 * one is available. Otherwise, it sleeps on the backlog queue
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
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
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
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.
36 * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
38 * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com>
41 #include <linux/module.h>
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>
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>
55 #include <trace/events/sunrpc.h>
65 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
66 # define RPCDBG_FACILITY RPCDBG_XPRT
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
);
77 static DEFINE_SPINLOCK(xprt_list_lock
);
78 static LIST_HEAD(xprt_list
);
80 static unsigned long xprt_request_timeout(const struct rpc_rqst
*req
)
82 unsigned long timeout
= jiffies
+ req
->rq_timeout
;
84 if (time_before(timeout
, req
->rq_majortimeo
))
86 return req
->rq_majortimeo
;
90 * xprt_register_transport - register a transport implementation
91 * @transport: transport to register
93 * If a transport implementation is loaded as a kernel module, it can
94 * call this interface to make itself known to the RPC client.
97 * 0: transport successfully registered
98 * -EEXIST: transport already registered
99 * -EINVAL: transport module being unloaded
101 int xprt_register_transport(struct xprt_class
*transport
)
103 struct xprt_class
*t
;
107 spin_lock(&xprt_list_lock
);
108 list_for_each_entry(t
, &xprt_list
, list
) {
109 /* don't register the same transport class twice */
110 if (t
->ident
== transport
->ident
)
114 list_add_tail(&transport
->list
, &xprt_list
);
115 printk(KERN_INFO
"RPC: Registered %s transport module.\n",
120 spin_unlock(&xprt_list_lock
);
123 EXPORT_SYMBOL_GPL(xprt_register_transport
);
126 * xprt_unregister_transport - unregister a transport implementation
127 * @transport: transport to unregister
130 * 0: transport successfully unregistered
131 * -ENOENT: transport never registered
133 int xprt_unregister_transport(struct xprt_class
*transport
)
135 struct xprt_class
*t
;
139 spin_lock(&xprt_list_lock
);
140 list_for_each_entry(t
, &xprt_list
, list
) {
141 if (t
== transport
) {
143 "RPC: Unregistered %s transport module.\n",
145 list_del_init(&transport
->list
);
152 spin_unlock(&xprt_list_lock
);
155 EXPORT_SYMBOL_GPL(xprt_unregister_transport
);
158 xprt_class_release(const struct xprt_class
*t
)
160 module_put(t
->owner
);
163 static const struct xprt_class
*
164 xprt_class_find_by_ident_locked(int ident
)
166 const struct xprt_class
*t
;
168 list_for_each_entry(t
, &xprt_list
, list
) {
169 if (t
->ident
!= ident
)
171 if (!try_module_get(t
->owner
))
178 static const struct xprt_class
*
179 xprt_class_find_by_ident(int ident
)
181 const struct xprt_class
*t
;
183 spin_lock(&xprt_list_lock
);
184 t
= xprt_class_find_by_ident_locked(ident
);
185 spin_unlock(&xprt_list_lock
);
189 static const struct xprt_class
*
190 xprt_class_find_by_netid_locked(const char *netid
)
192 const struct xprt_class
*t
;
195 list_for_each_entry(t
, &xprt_list
, list
) {
196 for (i
= 0; t
->netid
[i
][0] != '\0'; i
++) {
197 if (strcmp(t
->netid
[i
], netid
) != 0)
199 if (!try_module_get(t
->owner
))
207 static const struct xprt_class
*
208 xprt_class_find_by_netid(const char *netid
)
210 const struct xprt_class
*t
;
212 spin_lock(&xprt_list_lock
);
213 t
= xprt_class_find_by_netid_locked(netid
);
215 spin_unlock(&xprt_list_lock
);
216 request_module("rpc%s", netid
);
217 spin_lock(&xprt_list_lock
);
218 t
= xprt_class_find_by_netid_locked(netid
);
220 spin_unlock(&xprt_list_lock
);
225 * xprt_find_transport_ident - convert a netid into a transport identifier
226 * @netid: transport to load
229 * > 0: transport identifier
230 * -ENOENT: transport module not available
232 int xprt_find_transport_ident(const char *netid
)
234 const struct xprt_class
*t
;
237 t
= xprt_class_find_by_netid(netid
);
241 xprt_class_release(t
);
244 EXPORT_SYMBOL_GPL(xprt_find_transport_ident
);
246 static void xprt_clear_locked(struct rpc_xprt
*xprt
)
248 xprt
->snd_task
= NULL
;
249 if (!test_bit(XPRT_CLOSE_WAIT
, &xprt
->state
)) {
250 smp_mb__before_atomic();
251 clear_bit(XPRT_LOCKED
, &xprt
->state
);
252 smp_mb__after_atomic();
254 queue_work(xprtiod_workqueue
, &xprt
->task_cleanup
);
258 * xprt_reserve_xprt - serialize write access to transports
259 * @task: task that is requesting access to the transport
260 * @xprt: pointer to the target transport
262 * This prevents mixing the payload of separate requests, and prevents
263 * transport connects from colliding with writes. No congestion control
266 int xprt_reserve_xprt(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
268 struct rpc_rqst
*req
= task
->tk_rqstp
;
270 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
)) {
271 if (task
== xprt
->snd_task
)
275 if (test_bit(XPRT_WRITE_SPACE
, &xprt
->state
))
277 xprt
->snd_task
= task
;
280 trace_xprt_reserve_xprt(xprt
, task
);
284 xprt_clear_locked(xprt
);
286 task
->tk_status
= -EAGAIN
;
287 if (RPC_IS_SOFT(task
))
288 rpc_sleep_on_timeout(&xprt
->sending
, task
, NULL
,
289 xprt_request_timeout(req
));
291 rpc_sleep_on(&xprt
->sending
, task
, NULL
);
294 EXPORT_SYMBOL_GPL(xprt_reserve_xprt
);
297 xprt_need_congestion_window_wait(struct rpc_xprt
*xprt
)
299 return test_bit(XPRT_CWND_WAIT
, &xprt
->state
);
303 xprt_set_congestion_window_wait(struct rpc_xprt
*xprt
)
305 if (!list_empty(&xprt
->xmit_queue
)) {
306 /* Peek at head of queue to see if it can make progress */
307 if (list_first_entry(&xprt
->xmit_queue
, struct rpc_rqst
,
311 set_bit(XPRT_CWND_WAIT
, &xprt
->state
);
315 xprt_test_and_clear_congestion_window_wait(struct rpc_xprt
*xprt
)
317 if (!RPCXPRT_CONGESTED(xprt
))
318 clear_bit(XPRT_CWND_WAIT
, &xprt
->state
);
322 * xprt_reserve_xprt_cong - serialize write access to transports
323 * @task: task that is requesting access to the transport
325 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
326 * integrated into the decision of whether a request is allowed to be
327 * woken up and given access to the transport.
328 * Note that the lock is only granted if we know there are free slots.
330 int xprt_reserve_xprt_cong(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
332 struct rpc_rqst
*req
= task
->tk_rqstp
;
334 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
)) {
335 if (task
== xprt
->snd_task
)
340 xprt
->snd_task
= task
;
343 if (test_bit(XPRT_WRITE_SPACE
, &xprt
->state
))
345 if (!xprt_need_congestion_window_wait(xprt
)) {
346 xprt
->snd_task
= task
;
350 xprt_clear_locked(xprt
);
352 task
->tk_status
= -EAGAIN
;
353 if (RPC_IS_SOFT(task
))
354 rpc_sleep_on_timeout(&xprt
->sending
, task
, NULL
,
355 xprt_request_timeout(req
));
357 rpc_sleep_on(&xprt
->sending
, task
, NULL
);
360 trace_xprt_reserve_cong(xprt
, task
);
363 EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong
);
365 static inline int xprt_lock_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
369 if (test_bit(XPRT_LOCKED
, &xprt
->state
) && xprt
->snd_task
== task
)
371 spin_lock(&xprt
->transport_lock
);
372 retval
= xprt
->ops
->reserve_xprt(xprt
, task
);
373 spin_unlock(&xprt
->transport_lock
);
377 static bool __xprt_lock_write_func(struct rpc_task
*task
, void *data
)
379 struct rpc_xprt
*xprt
= data
;
381 xprt
->snd_task
= task
;
385 static void __xprt_lock_write_next(struct rpc_xprt
*xprt
)
387 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
389 if (test_bit(XPRT_WRITE_SPACE
, &xprt
->state
))
391 if (rpc_wake_up_first_on_wq(xprtiod_workqueue
, &xprt
->sending
,
392 __xprt_lock_write_func
, xprt
))
395 xprt_clear_locked(xprt
);
398 static void __xprt_lock_write_next_cong(struct rpc_xprt
*xprt
)
400 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
402 if (test_bit(XPRT_WRITE_SPACE
, &xprt
->state
))
404 if (xprt_need_congestion_window_wait(xprt
))
406 if (rpc_wake_up_first_on_wq(xprtiod_workqueue
, &xprt
->sending
,
407 __xprt_lock_write_func
, xprt
))
410 xprt_clear_locked(xprt
);
414 * xprt_release_xprt - allow other requests to use a transport
415 * @xprt: transport with other tasks potentially waiting
416 * @task: task that is releasing access to the transport
418 * Note that "task" can be NULL. No congestion control is provided.
420 void xprt_release_xprt(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
422 if (xprt
->snd_task
== task
) {
423 xprt_clear_locked(xprt
);
424 __xprt_lock_write_next(xprt
);
426 trace_xprt_release_xprt(xprt
, task
);
428 EXPORT_SYMBOL_GPL(xprt_release_xprt
);
431 * xprt_release_xprt_cong - allow other requests to use a transport
432 * @xprt: transport with other tasks potentially waiting
433 * @task: task that is releasing access to the transport
435 * Note that "task" can be NULL. Another task is awoken to use the
436 * transport if the transport's congestion window allows it.
438 void xprt_release_xprt_cong(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
440 if (xprt
->snd_task
== task
) {
441 xprt_clear_locked(xprt
);
442 __xprt_lock_write_next_cong(xprt
);
444 trace_xprt_release_cong(xprt
, task
);
446 EXPORT_SYMBOL_GPL(xprt_release_xprt_cong
);
448 void xprt_release_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
450 if (xprt
->snd_task
!= task
)
452 spin_lock(&xprt
->transport_lock
);
453 xprt
->ops
->release_xprt(xprt
, task
);
454 spin_unlock(&xprt
->transport_lock
);
458 * Van Jacobson congestion avoidance. Check if the congestion window
459 * overflowed. Put the task to sleep if this is the case.
462 __xprt_get_cong(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
466 trace_xprt_get_cong(xprt
, req
->rq_task
);
467 if (RPCXPRT_CONGESTED(xprt
)) {
468 xprt_set_congestion_window_wait(xprt
);
472 xprt
->cong
+= RPC_CWNDSCALE
;
477 * Adjust the congestion window, and wake up the next task
478 * that has been sleeping due to congestion
481 __xprt_put_cong(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
486 xprt
->cong
-= RPC_CWNDSCALE
;
487 xprt_test_and_clear_congestion_window_wait(xprt
);
488 trace_xprt_put_cong(xprt
, req
->rq_task
);
489 __xprt_lock_write_next_cong(xprt
);
493 * xprt_request_get_cong - Request congestion control credits
494 * @xprt: pointer to transport
495 * @req: pointer to RPC request
497 * Useful for transports that require congestion control.
500 xprt_request_get_cong(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
506 spin_lock(&xprt
->transport_lock
);
507 ret
= __xprt_get_cong(xprt
, req
) != 0;
508 spin_unlock(&xprt
->transport_lock
);
511 EXPORT_SYMBOL_GPL(xprt_request_get_cong
);
514 * xprt_release_rqst_cong - housekeeping when request is complete
515 * @task: RPC request that recently completed
517 * Useful for transports that require congestion control.
519 void xprt_release_rqst_cong(struct rpc_task
*task
)
521 struct rpc_rqst
*req
= task
->tk_rqstp
;
523 __xprt_put_cong(req
->rq_xprt
, req
);
525 EXPORT_SYMBOL_GPL(xprt_release_rqst_cong
);
527 static void xprt_clear_congestion_window_wait_locked(struct rpc_xprt
*xprt
)
529 if (test_and_clear_bit(XPRT_CWND_WAIT
, &xprt
->state
))
530 __xprt_lock_write_next_cong(xprt
);
534 * Clear the congestion window wait flag and wake up the next
535 * entry on xprt->sending
538 xprt_clear_congestion_window_wait(struct rpc_xprt
*xprt
)
540 if (test_and_clear_bit(XPRT_CWND_WAIT
, &xprt
->state
)) {
541 spin_lock(&xprt
->transport_lock
);
542 __xprt_lock_write_next_cong(xprt
);
543 spin_unlock(&xprt
->transport_lock
);
548 * xprt_adjust_cwnd - adjust transport congestion window
549 * @xprt: pointer to xprt
550 * @task: recently completed RPC request used to adjust window
551 * @result: result code of completed RPC request
553 * The transport code maintains an estimate on the maximum number of out-
554 * standing RPC requests, using a smoothed version of the congestion
555 * avoidance implemented in 44BSD. This is basically the Van Jacobson
556 * congestion algorithm: If a retransmit occurs, the congestion window is
557 * halved; otherwise, it is incremented by 1/cwnd when
559 * - a reply is received and
560 * - a full number of requests are outstanding and
561 * - the congestion window hasn't been updated recently.
563 void xprt_adjust_cwnd(struct rpc_xprt
*xprt
, struct rpc_task
*task
, int result
)
565 struct rpc_rqst
*req
= task
->tk_rqstp
;
566 unsigned long cwnd
= xprt
->cwnd
;
568 if (result
>= 0 && cwnd
<= xprt
->cong
) {
569 /* The (cwnd >> 1) term makes sure
570 * the result gets rounded properly. */
571 cwnd
+= (RPC_CWNDSCALE
* RPC_CWNDSCALE
+ (cwnd
>> 1)) / cwnd
;
572 if (cwnd
> RPC_MAXCWND(xprt
))
573 cwnd
= RPC_MAXCWND(xprt
);
574 __xprt_lock_write_next_cong(xprt
);
575 } else if (result
== -ETIMEDOUT
) {
577 if (cwnd
< RPC_CWNDSCALE
)
578 cwnd
= RPC_CWNDSCALE
;
580 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
581 xprt
->cong
, xprt
->cwnd
, cwnd
);
583 __xprt_put_cong(xprt
, req
);
585 EXPORT_SYMBOL_GPL(xprt_adjust_cwnd
);
588 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
589 * @xprt: transport with waiting tasks
590 * @status: result code to plant in each task before waking it
593 void xprt_wake_pending_tasks(struct rpc_xprt
*xprt
, int status
)
596 rpc_wake_up_status(&xprt
->pending
, status
);
598 rpc_wake_up(&xprt
->pending
);
600 EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks
);
603 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
606 * Note that we only set the timer for the case of RPC_IS_SOFT(), since
607 * we don't in general want to force a socket disconnection due to
608 * an incomplete RPC call transmission.
610 void xprt_wait_for_buffer_space(struct rpc_xprt
*xprt
)
612 set_bit(XPRT_WRITE_SPACE
, &xprt
->state
);
614 EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space
);
617 xprt_clear_write_space_locked(struct rpc_xprt
*xprt
)
619 if (test_and_clear_bit(XPRT_WRITE_SPACE
, &xprt
->state
)) {
620 __xprt_lock_write_next(xprt
);
621 dprintk("RPC: write space: waking waiting task on "
629 * xprt_write_space - wake the task waiting for transport output buffer space
630 * @xprt: transport with waiting tasks
632 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
634 bool xprt_write_space(struct rpc_xprt
*xprt
)
638 if (!test_bit(XPRT_WRITE_SPACE
, &xprt
->state
))
640 spin_lock(&xprt
->transport_lock
);
641 ret
= xprt_clear_write_space_locked(xprt
);
642 spin_unlock(&xprt
->transport_lock
);
645 EXPORT_SYMBOL_GPL(xprt_write_space
);
647 static unsigned long xprt_abs_ktime_to_jiffies(ktime_t abstime
)
649 s64 delta
= ktime_to_ns(ktime_get() - abstime
);
650 return likely(delta
>= 0) ?
651 jiffies
- nsecs_to_jiffies(delta
) :
652 jiffies
+ nsecs_to_jiffies(-delta
);
655 static unsigned long xprt_calc_majortimeo(struct rpc_rqst
*req
)
657 const struct rpc_timeout
*to
= req
->rq_task
->tk_client
->cl_timeout
;
658 unsigned long majortimeo
= req
->rq_timeout
;
660 if (to
->to_exponential
)
661 majortimeo
<<= to
->to_retries
;
663 majortimeo
+= to
->to_increment
* to
->to_retries
;
664 if (majortimeo
> to
->to_maxval
|| majortimeo
== 0)
665 majortimeo
= to
->to_maxval
;
669 static void xprt_reset_majortimeo(struct rpc_rqst
*req
)
671 req
->rq_majortimeo
+= xprt_calc_majortimeo(req
);
674 static void xprt_reset_minortimeo(struct rpc_rqst
*req
)
676 req
->rq_minortimeo
+= req
->rq_timeout
;
679 static void xprt_init_majortimeo(struct rpc_task
*task
, struct rpc_rqst
*req
)
681 unsigned long time_init
;
682 struct rpc_xprt
*xprt
= req
->rq_xprt
;
684 if (likely(xprt
&& xprt_connected(xprt
)))
687 time_init
= xprt_abs_ktime_to_jiffies(task
->tk_start
);
688 req
->rq_timeout
= task
->tk_client
->cl_timeout
->to_initval
;
689 req
->rq_majortimeo
= time_init
+ xprt_calc_majortimeo(req
);
690 req
->rq_minortimeo
= time_init
+ req
->rq_timeout
;
694 * xprt_adjust_timeout - adjust timeout values for next retransmit
695 * @req: RPC request containing parameters to use for the adjustment
698 int xprt_adjust_timeout(struct rpc_rqst
*req
)
700 struct rpc_xprt
*xprt
= req
->rq_xprt
;
701 const struct rpc_timeout
*to
= req
->rq_task
->tk_client
->cl_timeout
;
704 if (time_before(jiffies
, req
->rq_majortimeo
)) {
705 if (time_before(jiffies
, req
->rq_minortimeo
))
707 if (to
->to_exponential
)
708 req
->rq_timeout
<<= 1;
710 req
->rq_timeout
+= to
->to_increment
;
711 if (to
->to_maxval
&& req
->rq_timeout
>= to
->to_maxval
)
712 req
->rq_timeout
= to
->to_maxval
;
715 req
->rq_timeout
= to
->to_initval
;
717 xprt_reset_majortimeo(req
);
718 /* Reset the RTT counters == "slow start" */
719 spin_lock(&xprt
->transport_lock
);
720 rpc_init_rtt(req
->rq_task
->tk_client
->cl_rtt
, to
->to_initval
);
721 spin_unlock(&xprt
->transport_lock
);
724 xprt_reset_minortimeo(req
);
726 if (req
->rq_timeout
== 0) {
727 printk(KERN_WARNING
"xprt_adjust_timeout: rq_timeout = 0!\n");
728 req
->rq_timeout
= 5 * HZ
;
733 static void xprt_autoclose(struct work_struct
*work
)
735 struct rpc_xprt
*xprt
=
736 container_of(work
, struct rpc_xprt
, task_cleanup
);
737 unsigned int pflags
= memalloc_nofs_save();
739 trace_xprt_disconnect_auto(xprt
);
740 clear_bit(XPRT_CLOSE_WAIT
, &xprt
->state
);
741 xprt
->ops
->close(xprt
);
742 xprt_release_write(xprt
, NULL
);
743 wake_up_bit(&xprt
->state
, XPRT_LOCKED
);
744 memalloc_nofs_restore(pflags
);
748 * xprt_disconnect_done - mark a transport as disconnected
749 * @xprt: transport to flag for disconnect
752 void xprt_disconnect_done(struct rpc_xprt
*xprt
)
754 trace_xprt_disconnect_done(xprt
);
755 spin_lock(&xprt
->transport_lock
);
756 xprt_clear_connected(xprt
);
757 xprt_clear_write_space_locked(xprt
);
758 xprt_clear_congestion_window_wait_locked(xprt
);
759 xprt_wake_pending_tasks(xprt
, -ENOTCONN
);
760 spin_unlock(&xprt
->transport_lock
);
762 EXPORT_SYMBOL_GPL(xprt_disconnect_done
);
765 * xprt_schedule_autoclose_locked - Try to schedule an autoclose RPC call
766 * @xprt: transport to disconnect
768 static void xprt_schedule_autoclose_locked(struct rpc_xprt
*xprt
)
770 if (test_and_set_bit(XPRT_CLOSE_WAIT
, &xprt
->state
))
772 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
) == 0)
773 queue_work(xprtiod_workqueue
, &xprt
->task_cleanup
);
774 else if (xprt
->snd_task
&& !test_bit(XPRT_SND_IS_COOKIE
, &xprt
->state
))
775 rpc_wake_up_queued_task_set_status(&xprt
->pending
,
776 xprt
->snd_task
, -ENOTCONN
);
780 * xprt_force_disconnect - force a transport to disconnect
781 * @xprt: transport to disconnect
784 void xprt_force_disconnect(struct rpc_xprt
*xprt
)
786 trace_xprt_disconnect_force(xprt
);
788 /* Don't race with the test_bit() in xprt_clear_locked() */
789 spin_lock(&xprt
->transport_lock
);
790 xprt_schedule_autoclose_locked(xprt
);
791 spin_unlock(&xprt
->transport_lock
);
793 EXPORT_SYMBOL_GPL(xprt_force_disconnect
);
796 xprt_connect_cookie(struct rpc_xprt
*xprt
)
798 return READ_ONCE(xprt
->connect_cookie
);
802 xprt_request_retransmit_after_disconnect(struct rpc_task
*task
)
804 struct rpc_rqst
*req
= task
->tk_rqstp
;
805 struct rpc_xprt
*xprt
= req
->rq_xprt
;
807 return req
->rq_connect_cookie
!= xprt_connect_cookie(xprt
) ||
808 !xprt_connected(xprt
);
812 * xprt_conditional_disconnect - force a transport to disconnect
813 * @xprt: transport to disconnect
814 * @cookie: 'connection cookie'
816 * This attempts to break the connection if and only if 'cookie' matches
817 * the current transport 'connection cookie'. It ensures that we don't
818 * try to break the connection more than once when we need to retransmit
819 * a batch of RPC requests.
822 void xprt_conditional_disconnect(struct rpc_xprt
*xprt
, unsigned int cookie
)
824 /* Don't race with the test_bit() in xprt_clear_locked() */
825 spin_lock(&xprt
->transport_lock
);
826 if (cookie
!= xprt
->connect_cookie
)
828 if (test_bit(XPRT_CLOSING
, &xprt
->state
))
830 xprt_schedule_autoclose_locked(xprt
);
832 spin_unlock(&xprt
->transport_lock
);
836 xprt_has_timer(const struct rpc_xprt
*xprt
)
838 return xprt
->idle_timeout
!= 0;
842 xprt_schedule_autodisconnect(struct rpc_xprt
*xprt
)
843 __must_hold(&xprt
->transport_lock
)
845 xprt
->last_used
= jiffies
;
846 if (RB_EMPTY_ROOT(&xprt
->recv_queue
) && xprt_has_timer(xprt
))
847 mod_timer(&xprt
->timer
, xprt
->last_used
+ xprt
->idle_timeout
);
851 xprt_init_autodisconnect(struct timer_list
*t
)
853 struct rpc_xprt
*xprt
= from_timer(xprt
, t
, timer
);
855 if (!RB_EMPTY_ROOT(&xprt
->recv_queue
))
857 /* Reset xprt->last_used to avoid connect/autodisconnect cycling */
858 xprt
->last_used
= jiffies
;
859 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
861 queue_work(xprtiod_workqueue
, &xprt
->task_cleanup
);
864 #if IS_ENABLED(CONFIG_FAIL_SUNRPC)
865 static void xprt_inject_disconnect(struct rpc_xprt
*xprt
)
867 if (!fail_sunrpc
.ignore_client_disconnect
&&
868 should_fail(&fail_sunrpc
.attr
, 1))
869 xprt
->ops
->inject_disconnect(xprt
);
872 static inline void xprt_inject_disconnect(struct rpc_xprt
*xprt
)
877 bool xprt_lock_connect(struct rpc_xprt
*xprt
,
878 struct rpc_task
*task
,
883 spin_lock(&xprt
->transport_lock
);
884 if (!test_bit(XPRT_LOCKED
, &xprt
->state
))
886 if (xprt
->snd_task
!= task
)
888 set_bit(XPRT_SND_IS_COOKIE
, &xprt
->state
);
889 xprt
->snd_task
= cookie
;
892 spin_unlock(&xprt
->transport_lock
);
895 EXPORT_SYMBOL_GPL(xprt_lock_connect
);
897 void xprt_unlock_connect(struct rpc_xprt
*xprt
, void *cookie
)
899 spin_lock(&xprt
->transport_lock
);
900 if (xprt
->snd_task
!= cookie
)
902 if (!test_bit(XPRT_LOCKED
, &xprt
->state
))
904 xprt
->snd_task
=NULL
;
905 clear_bit(XPRT_SND_IS_COOKIE
, &xprt
->state
);
906 xprt
->ops
->release_xprt(xprt
, NULL
);
907 xprt_schedule_autodisconnect(xprt
);
909 spin_unlock(&xprt
->transport_lock
);
910 wake_up_bit(&xprt
->state
, XPRT_LOCKED
);
912 EXPORT_SYMBOL_GPL(xprt_unlock_connect
);
915 * xprt_connect - schedule a transport connect operation
916 * @task: RPC task that is requesting the connect
919 void xprt_connect(struct rpc_task
*task
)
921 struct rpc_xprt
*xprt
= task
->tk_rqstp
->rq_xprt
;
923 trace_xprt_connect(xprt
);
925 if (!xprt_bound(xprt
)) {
926 task
->tk_status
= -EAGAIN
;
929 if (!xprt_lock_write(xprt
, task
))
932 if (test_and_clear_bit(XPRT_CLOSE_WAIT
, &xprt
->state
)) {
933 trace_xprt_disconnect_cleanup(xprt
);
934 xprt
->ops
->close(xprt
);
937 if (!xprt_connected(xprt
)) {
938 task
->tk_rqstp
->rq_connect_cookie
= xprt
->connect_cookie
;
939 rpc_sleep_on_timeout(&xprt
->pending
, task
, NULL
,
940 xprt_request_timeout(task
->tk_rqstp
));
942 if (test_bit(XPRT_CLOSING
, &xprt
->state
))
944 if (xprt_test_and_set_connecting(xprt
))
947 if (!xprt_connected(xprt
)) {
948 xprt
->stat
.connect_start
= jiffies
;
949 xprt
->ops
->connect(xprt
, task
);
951 xprt_clear_connecting(xprt
);
953 rpc_wake_up_queued_task(&xprt
->pending
, task
);
956 xprt_release_write(xprt
, task
);
960 * xprt_reconnect_delay - compute the wait before scheduling a connect
961 * @xprt: transport instance
964 unsigned long xprt_reconnect_delay(const struct rpc_xprt
*xprt
)
966 unsigned long start
, now
= jiffies
;
968 start
= xprt
->stat
.connect_start
+ xprt
->reestablish_timeout
;
969 if (time_after(start
, now
))
973 EXPORT_SYMBOL_GPL(xprt_reconnect_delay
);
976 * xprt_reconnect_backoff - compute the new re-establish timeout
977 * @xprt: transport instance
978 * @init_to: initial reestablish timeout
981 void xprt_reconnect_backoff(struct rpc_xprt
*xprt
, unsigned long init_to
)
983 xprt
->reestablish_timeout
<<= 1;
984 if (xprt
->reestablish_timeout
> xprt
->max_reconnect_timeout
)
985 xprt
->reestablish_timeout
= xprt
->max_reconnect_timeout
;
986 if (xprt
->reestablish_timeout
< init_to
)
987 xprt
->reestablish_timeout
= init_to
;
989 EXPORT_SYMBOL_GPL(xprt_reconnect_backoff
);
991 enum xprt_xid_rb_cmp
{
996 static enum xprt_xid_rb_cmp
997 xprt_xid_cmp(__be32 xid1
, __be32 xid2
)
1000 return XID_RB_EQUAL
;
1001 if ((__force u32
)xid1
< (__force u32
)xid2
)
1003 return XID_RB_RIGHT
;
1006 static struct rpc_rqst
*
1007 xprt_request_rb_find(struct rpc_xprt
*xprt
, __be32 xid
)
1009 struct rb_node
*n
= xprt
->recv_queue
.rb_node
;
1010 struct rpc_rqst
*req
;
1013 req
= rb_entry(n
, struct rpc_rqst
, rq_recv
);
1014 switch (xprt_xid_cmp(xid
, req
->rq_xid
)) {
1029 xprt_request_rb_insert(struct rpc_xprt
*xprt
, struct rpc_rqst
*new)
1031 struct rb_node
**p
= &xprt
->recv_queue
.rb_node
;
1032 struct rb_node
*n
= NULL
;
1033 struct rpc_rqst
*req
;
1035 while (*p
!= NULL
) {
1037 req
= rb_entry(n
, struct rpc_rqst
, rq_recv
);
1038 switch(xprt_xid_cmp(new->rq_xid
, req
->rq_xid
)) {
1046 WARN_ON_ONCE(new != req
);
1050 rb_link_node(&new->rq_recv
, n
, p
);
1051 rb_insert_color(&new->rq_recv
, &xprt
->recv_queue
);
1055 xprt_request_rb_remove(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
1057 rb_erase(&req
->rq_recv
, &xprt
->recv_queue
);
1061 * xprt_lookup_rqst - find an RPC request corresponding to an XID
1062 * @xprt: transport on which the original request was transmitted
1063 * @xid: RPC XID of incoming reply
1065 * Caller holds xprt->queue_lock.
1067 struct rpc_rqst
*xprt_lookup_rqst(struct rpc_xprt
*xprt
, __be32 xid
)
1069 struct rpc_rqst
*entry
;
1071 entry
= xprt_request_rb_find(xprt
, xid
);
1072 if (entry
!= NULL
) {
1073 trace_xprt_lookup_rqst(xprt
, xid
, 0);
1074 entry
->rq_rtt
= ktime_sub(ktime_get(), entry
->rq_xtime
);
1078 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
1080 trace_xprt_lookup_rqst(xprt
, xid
, -ENOENT
);
1081 xprt
->stat
.bad_xids
++;
1084 EXPORT_SYMBOL_GPL(xprt_lookup_rqst
);
1087 xprt_is_pinned_rqst(struct rpc_rqst
*req
)
1089 return atomic_read(&req
->rq_pin
) != 0;
1093 * xprt_pin_rqst - Pin a request on the transport receive list
1094 * @req: Request to pin
1096 * Caller must ensure this is atomic with the call to xprt_lookup_rqst()
1097 * so should be holding xprt->queue_lock.
1099 void xprt_pin_rqst(struct rpc_rqst
*req
)
1101 atomic_inc(&req
->rq_pin
);
1103 EXPORT_SYMBOL_GPL(xprt_pin_rqst
);
1106 * xprt_unpin_rqst - Unpin a request on the transport receive list
1107 * @req: Request to pin
1109 * Caller should be holding xprt->queue_lock.
1111 void xprt_unpin_rqst(struct rpc_rqst
*req
)
1113 if (!test_bit(RPC_TASK_MSG_PIN_WAIT
, &req
->rq_task
->tk_runstate
)) {
1114 atomic_dec(&req
->rq_pin
);
1117 if (atomic_dec_and_test(&req
->rq_pin
))
1118 wake_up_var(&req
->rq_pin
);
1120 EXPORT_SYMBOL_GPL(xprt_unpin_rqst
);
1122 static void xprt_wait_on_pinned_rqst(struct rpc_rqst
*req
)
1124 wait_var_event(&req
->rq_pin
, !xprt_is_pinned_rqst(req
));
1128 xprt_request_data_received(struct rpc_task
*task
)
1130 return !test_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
) &&
1131 READ_ONCE(task
->tk_rqstp
->rq_reply_bytes_recvd
) != 0;
1135 xprt_request_need_enqueue_receive(struct rpc_task
*task
, struct rpc_rqst
*req
)
1137 return !test_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
) &&
1138 READ_ONCE(task
->tk_rqstp
->rq_reply_bytes_recvd
) == 0;
1142 * xprt_request_enqueue_receive - Add an request to the receive queue
1147 xprt_request_enqueue_receive(struct rpc_task
*task
)
1149 struct rpc_rqst
*req
= task
->tk_rqstp
;
1150 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1152 if (!xprt_request_need_enqueue_receive(task
, req
))
1155 xprt_request_prepare(task
->tk_rqstp
);
1156 spin_lock(&xprt
->queue_lock
);
1158 /* Update the softirq receive buffer */
1159 memcpy(&req
->rq_private_buf
, &req
->rq_rcv_buf
,
1160 sizeof(req
->rq_private_buf
));
1162 /* Add request to the receive list */
1163 xprt_request_rb_insert(xprt
, req
);
1164 set_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
);
1165 spin_unlock(&xprt
->queue_lock
);
1167 /* Turn off autodisconnect */
1168 del_singleshot_timer_sync(&xprt
->timer
);
1172 * xprt_request_dequeue_receive_locked - Remove a request from the receive queue
1175 * Caller must hold xprt->queue_lock.
1178 xprt_request_dequeue_receive_locked(struct rpc_task
*task
)
1180 struct rpc_rqst
*req
= task
->tk_rqstp
;
1182 if (test_and_clear_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
))
1183 xprt_request_rb_remove(req
->rq_xprt
, req
);
1187 * xprt_update_rtt - Update RPC RTT statistics
1188 * @task: RPC request that recently completed
1190 * Caller holds xprt->queue_lock.
1192 void xprt_update_rtt(struct rpc_task
*task
)
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(ktime_to_us(req
->rq_rtt
));
1200 if (req
->rq_ntrans
== 1)
1201 rpc_update_rtt(rtt
, timer
, m
);
1202 rpc_set_timeo(rtt
, timer
, req
->rq_ntrans
- 1);
1205 EXPORT_SYMBOL_GPL(xprt_update_rtt
);
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
1212 * Caller holds xprt->queue_lock.
1214 void xprt_complete_rqst(struct rpc_task
*task
, int copied
)
1216 struct rpc_rqst
*req
= task
->tk_rqstp
;
1217 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1221 req
->rq_private_buf
.len
= copied
;
1222 /* Ensure all writes are done before we update */
1223 /* req->rq_reply_bytes_recvd */
1225 req
->rq_reply_bytes_recvd
= copied
;
1226 xprt_request_dequeue_receive_locked(task
);
1227 rpc_wake_up_queued_task(&xprt
->pending
, task
);
1229 EXPORT_SYMBOL_GPL(xprt_complete_rqst
);
1231 static void xprt_timer(struct rpc_task
*task
)
1233 struct rpc_rqst
*req
= task
->tk_rqstp
;
1234 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1236 if (task
->tk_status
!= -ETIMEDOUT
)
1239 trace_xprt_timer(xprt
, req
->rq_xid
, task
->tk_status
);
1240 if (!req
->rq_reply_bytes_recvd
) {
1241 if (xprt
->ops
->timer
)
1242 xprt
->ops
->timer(xprt
, task
);
1244 task
->tk_status
= 0;
1248 * xprt_wait_for_reply_request_def - wait for reply
1249 * @task: pointer to rpc_task
1251 * Set a request's retransmit timeout based on the transport's
1252 * default timeout parameters. Used by transports that don't adjust
1253 * the retransmit timeout based on round-trip time estimation,
1254 * and put the task to sleep on the pending queue.
1256 void xprt_wait_for_reply_request_def(struct rpc_task
*task
)
1258 struct rpc_rqst
*req
= task
->tk_rqstp
;
1260 rpc_sleep_on_timeout(&req
->rq_xprt
->pending
, task
, xprt_timer
,
1261 xprt_request_timeout(req
));
1263 EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_def
);
1266 * xprt_wait_for_reply_request_rtt - wait for reply using RTT estimator
1267 * @task: pointer to rpc_task
1269 * Set a request's retransmit timeout using the RTT estimator,
1270 * and put the task to sleep on the pending queue.
1272 void xprt_wait_for_reply_request_rtt(struct rpc_task
*task
)
1274 int timer
= task
->tk_msg
.rpc_proc
->p_timer
;
1275 struct rpc_clnt
*clnt
= task
->tk_client
;
1276 struct rpc_rtt
*rtt
= clnt
->cl_rtt
;
1277 struct rpc_rqst
*req
= task
->tk_rqstp
;
1278 unsigned long max_timeout
= clnt
->cl_timeout
->to_maxval
;
1279 unsigned long timeout
;
1281 timeout
= rpc_calc_rto(rtt
, timer
);
1282 timeout
<<= rpc_ntimeo(rtt
, timer
) + req
->rq_retries
;
1283 if (timeout
> max_timeout
|| timeout
== 0)
1284 timeout
= max_timeout
;
1285 rpc_sleep_on_timeout(&req
->rq_xprt
->pending
, task
, xprt_timer
,
1288 EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_rtt
);
1291 * xprt_request_wait_receive - wait for the reply to an RPC request
1292 * @task: RPC task about to send a request
1295 void xprt_request_wait_receive(struct rpc_task
*task
)
1297 struct rpc_rqst
*req
= task
->tk_rqstp
;
1298 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1300 if (!test_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
))
1303 * Sleep on the pending queue if we're expecting a reply.
1304 * The spinlock ensures atomicity between the test of
1305 * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on().
1307 spin_lock(&xprt
->queue_lock
);
1308 if (test_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
)) {
1309 xprt
->ops
->wait_for_reply_request(task
);
1311 * Send an extra queue wakeup call if the
1312 * connection was dropped in case the call to
1313 * rpc_sleep_on() raced.
1315 if (xprt_request_retransmit_after_disconnect(task
))
1316 rpc_wake_up_queued_task_set_status(&xprt
->pending
,
1319 spin_unlock(&xprt
->queue_lock
);
1323 xprt_request_need_enqueue_transmit(struct rpc_task
*task
, struct rpc_rqst
*req
)
1325 return !test_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
);
1329 * xprt_request_enqueue_transmit - queue a task for transmission
1330 * @task: pointer to rpc_task
1332 * Add a task to the transmission queue.
1335 xprt_request_enqueue_transmit(struct rpc_task
*task
)
1337 struct rpc_rqst
*pos
, *req
= task
->tk_rqstp
;
1338 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1340 if (xprt_request_need_enqueue_transmit(task
, req
)) {
1341 req
->rq_bytes_sent
= 0;
1342 spin_lock(&xprt
->queue_lock
);
1344 * Requests that carry congestion control credits are added
1345 * to the head of the list to avoid starvation issues.
1348 xprt_clear_congestion_window_wait(xprt
);
1349 list_for_each_entry(pos
, &xprt
->xmit_queue
, rq_xmit
) {
1352 /* Note: req is added _before_ pos */
1353 list_add_tail(&req
->rq_xmit
, &pos
->rq_xmit
);
1354 INIT_LIST_HEAD(&req
->rq_xmit2
);
1357 } else if (!req
->rq_seqno
) {
1358 list_for_each_entry(pos
, &xprt
->xmit_queue
, rq_xmit
) {
1359 if (pos
->rq_task
->tk_owner
!= task
->tk_owner
)
1361 list_add_tail(&req
->rq_xmit2
, &pos
->rq_xmit2
);
1362 INIT_LIST_HEAD(&req
->rq_xmit
);
1366 list_add_tail(&req
->rq_xmit
, &xprt
->xmit_queue
);
1367 INIT_LIST_HEAD(&req
->rq_xmit2
);
1369 atomic_long_inc(&xprt
->xmit_queuelen
);
1370 set_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
);
1371 spin_unlock(&xprt
->queue_lock
);
1376 * xprt_request_dequeue_transmit_locked - remove a task from the transmission queue
1377 * @task: pointer to rpc_task
1379 * Remove a task from the transmission queue
1380 * Caller must hold xprt->queue_lock
1383 xprt_request_dequeue_transmit_locked(struct rpc_task
*task
)
1385 struct rpc_rqst
*req
= task
->tk_rqstp
;
1387 if (!test_and_clear_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
))
1389 if (!list_empty(&req
->rq_xmit
)) {
1390 list_del(&req
->rq_xmit
);
1391 if (!list_empty(&req
->rq_xmit2
)) {
1392 struct rpc_rqst
*next
= list_first_entry(&req
->rq_xmit2
,
1393 struct rpc_rqst
, rq_xmit2
);
1394 list_del(&req
->rq_xmit2
);
1395 list_add_tail(&next
->rq_xmit
, &next
->rq_xprt
->xmit_queue
);
1398 list_del(&req
->rq_xmit2
);
1399 atomic_long_dec(&req
->rq_xprt
->xmit_queuelen
);
1403 * xprt_request_dequeue_transmit - remove a task from the transmission queue
1404 * @task: pointer to rpc_task
1406 * Remove a task from the transmission queue
1409 xprt_request_dequeue_transmit(struct rpc_task
*task
)
1411 struct rpc_rqst
*req
= task
->tk_rqstp
;
1412 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1414 spin_lock(&xprt
->queue_lock
);
1415 xprt_request_dequeue_transmit_locked(task
);
1416 spin_unlock(&xprt
->queue_lock
);
1420 * xprt_request_dequeue_xprt - remove a task from the transmit+receive queue
1421 * @task: pointer to rpc_task
1423 * Remove a task from the transmit and receive queues, and ensure that
1424 * it is not pinned by the receive work item.
1427 xprt_request_dequeue_xprt(struct rpc_task
*task
)
1429 struct rpc_rqst
*req
= task
->tk_rqstp
;
1430 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1432 if (test_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
) ||
1433 test_bit(RPC_TASK_NEED_RECV
, &task
->tk_runstate
) ||
1434 xprt_is_pinned_rqst(req
)) {
1435 spin_lock(&xprt
->queue_lock
);
1436 xprt_request_dequeue_transmit_locked(task
);
1437 xprt_request_dequeue_receive_locked(task
);
1438 while (xprt_is_pinned_rqst(req
)) {
1439 set_bit(RPC_TASK_MSG_PIN_WAIT
, &task
->tk_runstate
);
1440 spin_unlock(&xprt
->queue_lock
);
1441 xprt_wait_on_pinned_rqst(req
);
1442 spin_lock(&xprt
->queue_lock
);
1443 clear_bit(RPC_TASK_MSG_PIN_WAIT
, &task
->tk_runstate
);
1445 spin_unlock(&xprt
->queue_lock
);
1450 * xprt_request_prepare - prepare an encoded request for transport
1451 * @req: pointer to rpc_rqst
1453 * Calls into the transport layer to do whatever is needed to prepare
1454 * the request for transmission or receive.
1457 xprt_request_prepare(struct rpc_rqst
*req
)
1459 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1461 if (xprt
->ops
->prepare_request
)
1462 xprt
->ops
->prepare_request(req
);
1466 * xprt_request_need_retransmit - Test if a task needs retransmission
1467 * @task: pointer to rpc_task
1469 * Test for whether a connection breakage requires the task to retransmit
1472 xprt_request_need_retransmit(struct rpc_task
*task
)
1474 return xprt_request_retransmit_after_disconnect(task
);
1478 * xprt_prepare_transmit - reserve the transport before sending a request
1479 * @task: RPC task about to send a request
1482 bool xprt_prepare_transmit(struct rpc_task
*task
)
1484 struct rpc_rqst
*req
= task
->tk_rqstp
;
1485 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1487 if (!xprt_lock_write(xprt
, task
)) {
1488 /* Race breaker: someone may have transmitted us */
1489 if (!test_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
))
1490 rpc_wake_up_queued_task_set_status(&xprt
->sending
,
1498 void xprt_end_transmit(struct rpc_task
*task
)
1500 struct rpc_xprt
*xprt
= task
->tk_rqstp
->rq_xprt
;
1502 xprt_inject_disconnect(xprt
);
1503 xprt_release_write(xprt
, task
);
1507 * xprt_request_transmit - send an RPC request on a transport
1508 * @req: pointer to request to transmit
1509 * @snd_task: RPC task that owns the transport lock
1511 * This performs the transmission of a single request.
1512 * Note that if the request is not the same as snd_task, then it
1513 * does need to be pinned.
1514 * Returns '0' on success.
1517 xprt_request_transmit(struct rpc_rqst
*req
, struct rpc_task
*snd_task
)
1519 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1520 struct rpc_task
*task
= req
->rq_task
;
1521 unsigned int connect_cookie
;
1522 int is_retrans
= RPC_WAS_SENT(task
);
1525 if (!req
->rq_bytes_sent
) {
1526 if (xprt_request_data_received(task
)) {
1530 /* Verify that our message lies in the RPCSEC_GSS window */
1531 if (rpcauth_xmit_need_reencode(task
)) {
1535 if (RPC_SIGNALLED(task
)) {
1536 status
= -ERESTARTSYS
;
1542 * Update req->rq_ntrans before transmitting to avoid races with
1543 * xprt_update_rtt(), which needs to know that it is recording a
1544 * reply to the first transmission.
1548 trace_rpc_xdr_sendto(task
, &req
->rq_snd_buf
);
1549 connect_cookie
= xprt
->connect_cookie
;
1550 status
= xprt
->ops
->send_request(req
);
1553 trace_xprt_transmit(req
, status
);
1558 task
->tk_client
->cl_stats
->rpcretrans
++;
1559 trace_xprt_retransmit(req
);
1562 xprt_inject_disconnect(xprt
);
1564 task
->tk_flags
|= RPC_TASK_SENT
;
1565 spin_lock(&xprt
->transport_lock
);
1568 xprt
->stat
.req_u
+= xprt
->stat
.sends
- xprt
->stat
.recvs
;
1569 xprt
->stat
.bklog_u
+= xprt
->backlog
.qlen
;
1570 xprt
->stat
.sending_u
+= xprt
->sending
.qlen
;
1571 xprt
->stat
.pending_u
+= xprt
->pending
.qlen
;
1572 spin_unlock(&xprt
->transport_lock
);
1574 req
->rq_connect_cookie
= connect_cookie
;
1576 trace_xprt_transmit(req
, status
);
1577 xprt_request_dequeue_transmit(task
);
1578 rpc_wake_up_queued_task_set_status(&xprt
->sending
, task
, status
);
1583 * xprt_transmit - send an RPC request on a transport
1584 * @task: controlling RPC task
1586 * Attempts to drain the transmit queue. On exit, either the transport
1587 * signalled an error that needs to be handled before transmission can
1588 * resume, or @task finished transmitting, and detected that it already
1592 xprt_transmit(struct rpc_task
*task
)
1594 struct rpc_rqst
*next
, *req
= task
->tk_rqstp
;
1595 struct rpc_xprt
*xprt
= req
->rq_xprt
;
1598 spin_lock(&xprt
->queue_lock
);
1600 next
= list_first_entry_or_null(&xprt
->xmit_queue
,
1601 struct rpc_rqst
, rq_xmit
);
1604 xprt_pin_rqst(next
);
1605 spin_unlock(&xprt
->queue_lock
);
1606 status
= xprt_request_transmit(next
, task
);
1607 if (status
== -EBADMSG
&& next
!= req
)
1609 spin_lock(&xprt
->queue_lock
);
1610 xprt_unpin_rqst(next
);
1612 if (test_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
))
1613 task
->tk_status
= status
;
1616 /* Was @task transmitted, and has it received a reply? */
1617 if (xprt_request_data_received(task
) &&
1618 !test_bit(RPC_TASK_NEED_XMIT
, &task
->tk_runstate
))
1620 cond_resched_lock(&xprt
->queue_lock
);
1622 spin_unlock(&xprt
->queue_lock
);
1625 static void xprt_complete_request_init(struct rpc_task
*task
)
1628 xprt_request_init(task
);
1631 void xprt_add_backlog(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
1633 set_bit(XPRT_CONGESTED
, &xprt
->state
);
1634 rpc_sleep_on(&xprt
->backlog
, task
, xprt_complete_request_init
);
1636 EXPORT_SYMBOL_GPL(xprt_add_backlog
);
1638 static bool __xprt_set_rq(struct rpc_task
*task
, void *data
)
1640 struct rpc_rqst
*req
= data
;
1642 if (task
->tk_rqstp
== NULL
) {
1643 memset(req
, 0, sizeof(*req
)); /* mark unused */
1644 task
->tk_rqstp
= req
;
1650 bool xprt_wake_up_backlog(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
1652 if (rpc_wake_up_first(&xprt
->backlog
, __xprt_set_rq
, req
) == NULL
) {
1653 clear_bit(XPRT_CONGESTED
, &xprt
->state
);
1658 EXPORT_SYMBOL_GPL(xprt_wake_up_backlog
);
1660 static bool xprt_throttle_congested(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
1664 if (!test_bit(XPRT_CONGESTED
, &xprt
->state
))
1666 spin_lock(&xprt
->reserve_lock
);
1667 if (test_bit(XPRT_CONGESTED
, &xprt
->state
)) {
1668 xprt_add_backlog(xprt
, task
);
1671 spin_unlock(&xprt
->reserve_lock
);
1676 static struct rpc_rqst
*xprt_dynamic_alloc_slot(struct rpc_xprt
*xprt
)
1678 struct rpc_rqst
*req
= ERR_PTR(-EAGAIN
);
1679 gfp_t gfp_mask
= GFP_KERNEL
;
1681 if (xprt
->num_reqs
>= xprt
->max_reqs
)
1684 spin_unlock(&xprt
->reserve_lock
);
1685 if (current
->flags
& PF_WQ_WORKER
)
1686 gfp_mask
|= __GFP_NORETRY
| __GFP_NOWARN
;
1687 req
= kzalloc(sizeof(*req
), gfp_mask
);
1688 spin_lock(&xprt
->reserve_lock
);
1692 req
= ERR_PTR(-ENOMEM
);
1697 static bool xprt_dynamic_free_slot(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
1699 if (xprt
->num_reqs
> xprt
->min_reqs
) {
1707 void xprt_alloc_slot(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
1709 struct rpc_rqst
*req
;
1711 spin_lock(&xprt
->reserve_lock
);
1712 if (!list_empty(&xprt
->free
)) {
1713 req
= list_entry(xprt
->free
.next
, struct rpc_rqst
, rq_list
);
1714 list_del(&req
->rq_list
);
1717 req
= xprt_dynamic_alloc_slot(xprt
);
1720 switch (PTR_ERR(req
)) {
1722 dprintk("RPC: dynamic allocation of request slot "
1723 "failed! Retrying\n");
1724 task
->tk_status
= -ENOMEM
;
1727 xprt_add_backlog(xprt
, task
);
1728 dprintk("RPC: waiting for request slot\n");
1731 task
->tk_status
= -EAGAIN
;
1733 spin_unlock(&xprt
->reserve_lock
);
1736 xprt
->stat
.max_slots
= max_t(unsigned int, xprt
->stat
.max_slots
,
1738 spin_unlock(&xprt
->reserve_lock
);
1740 task
->tk_status
= 0;
1741 task
->tk_rqstp
= req
;
1743 EXPORT_SYMBOL_GPL(xprt_alloc_slot
);
1745 void xprt_free_slot(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
1747 spin_lock(&xprt
->reserve_lock
);
1748 if (!xprt_wake_up_backlog(xprt
, req
) &&
1749 !xprt_dynamic_free_slot(xprt
, req
)) {
1750 memset(req
, 0, sizeof(*req
)); /* mark unused */
1751 list_add(&req
->rq_list
, &xprt
->free
);
1753 spin_unlock(&xprt
->reserve_lock
);
1755 EXPORT_SYMBOL_GPL(xprt_free_slot
);
1757 static void xprt_free_all_slots(struct rpc_xprt
*xprt
)
1759 struct rpc_rqst
*req
;
1760 while (!list_empty(&xprt
->free
)) {
1761 req
= list_first_entry(&xprt
->free
, struct rpc_rqst
, rq_list
);
1762 list_del(&req
->rq_list
);
1767 static DEFINE_IDA(rpc_xprt_ids
);
1769 void xprt_cleanup_ids(void)
1771 ida_destroy(&rpc_xprt_ids
);
1774 static int xprt_alloc_id(struct rpc_xprt
*xprt
)
1778 id
= ida_simple_get(&rpc_xprt_ids
, 0, 0, GFP_KERNEL
);
1786 static void xprt_free_id(struct rpc_xprt
*xprt
)
1788 ida_simple_remove(&rpc_xprt_ids
, xprt
->id
);
1791 struct rpc_xprt
*xprt_alloc(struct net
*net
, size_t size
,
1792 unsigned int num_prealloc
,
1793 unsigned int max_alloc
)
1795 struct rpc_xprt
*xprt
;
1796 struct rpc_rqst
*req
;
1799 xprt
= kzalloc(size
, GFP_KERNEL
);
1803 xprt_alloc_id(xprt
);
1804 xprt_init(xprt
, net
);
1806 for (i
= 0; i
< num_prealloc
; i
++) {
1807 req
= kzalloc(sizeof(struct rpc_rqst
), GFP_KERNEL
);
1810 list_add(&req
->rq_list
, &xprt
->free
);
1812 if (max_alloc
> num_prealloc
)
1813 xprt
->max_reqs
= max_alloc
;
1815 xprt
->max_reqs
= num_prealloc
;
1816 xprt
->min_reqs
= num_prealloc
;
1817 xprt
->num_reqs
= num_prealloc
;
1826 EXPORT_SYMBOL_GPL(xprt_alloc
);
1828 void xprt_free(struct rpc_xprt
*xprt
)
1830 put_net(xprt
->xprt_net
);
1831 xprt_free_all_slots(xprt
);
1833 rpc_sysfs_xprt_destroy(xprt
);
1834 kfree_rcu(xprt
, rcu
);
1836 EXPORT_SYMBOL_GPL(xprt_free
);
1839 xprt_init_connect_cookie(struct rpc_rqst
*req
, struct rpc_xprt
*xprt
)
1841 req
->rq_connect_cookie
= xprt_connect_cookie(xprt
) - 1;
1845 xprt_alloc_xid(struct rpc_xprt
*xprt
)
1849 spin_lock(&xprt
->reserve_lock
);
1850 xid
= (__force __be32
)xprt
->xid
++;
1851 spin_unlock(&xprt
->reserve_lock
);
1856 xprt_init_xid(struct rpc_xprt
*xprt
)
1858 xprt
->xid
= prandom_u32();
1862 xprt_request_init(struct rpc_task
*task
)
1864 struct rpc_xprt
*xprt
= task
->tk_xprt
;
1865 struct rpc_rqst
*req
= task
->tk_rqstp
;
1867 req
->rq_task
= task
;
1868 req
->rq_xprt
= xprt
;
1869 req
->rq_buffer
= NULL
;
1870 req
->rq_xid
= xprt_alloc_xid(xprt
);
1871 xprt_init_connect_cookie(req
, xprt
);
1872 req
->rq_snd_buf
.len
= 0;
1873 req
->rq_snd_buf
.buflen
= 0;
1874 req
->rq_rcv_buf
.len
= 0;
1875 req
->rq_rcv_buf
.buflen
= 0;
1876 req
->rq_snd_buf
.bvec
= NULL
;
1877 req
->rq_rcv_buf
.bvec
= NULL
;
1878 req
->rq_release_snd_buf
= NULL
;
1879 xprt_init_majortimeo(task
, req
);
1881 trace_xprt_reserve(req
);
1885 xprt_do_reserve(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
1887 xprt
->ops
->alloc_slot(xprt
, task
);
1888 if (task
->tk_rqstp
!= NULL
)
1889 xprt_request_init(task
);
1893 * xprt_reserve - allocate an RPC request slot
1894 * @task: RPC task requesting a slot allocation
1896 * If the transport is marked as being congested, or if no more
1897 * slots are available, place the task on the transport's
1900 void xprt_reserve(struct rpc_task
*task
)
1902 struct rpc_xprt
*xprt
= task
->tk_xprt
;
1904 task
->tk_status
= 0;
1905 if (task
->tk_rqstp
!= NULL
)
1908 task
->tk_status
= -EAGAIN
;
1909 if (!xprt_throttle_congested(xprt
, task
))
1910 xprt_do_reserve(xprt
, task
);
1914 * xprt_retry_reserve - allocate an RPC request slot
1915 * @task: RPC task requesting a slot allocation
1917 * If no more slots are available, place the task on the transport's
1919 * Note that the only difference with xprt_reserve is that we now
1920 * ignore the value of the XPRT_CONGESTED flag.
1922 void xprt_retry_reserve(struct rpc_task
*task
)
1924 struct rpc_xprt
*xprt
= task
->tk_xprt
;
1926 task
->tk_status
= 0;
1927 if (task
->tk_rqstp
!= NULL
)
1930 task
->tk_status
= -EAGAIN
;
1931 xprt_do_reserve(xprt
, task
);
1935 * xprt_release - release an RPC request slot
1936 * @task: task which is finished with the slot
1939 void xprt_release(struct rpc_task
*task
)
1941 struct rpc_xprt
*xprt
;
1942 struct rpc_rqst
*req
= task
->tk_rqstp
;
1945 if (task
->tk_client
) {
1946 xprt
= task
->tk_xprt
;
1947 xprt_release_write(xprt
, task
);
1952 xprt
= req
->rq_xprt
;
1953 xprt_request_dequeue_xprt(task
);
1954 spin_lock(&xprt
->transport_lock
);
1955 xprt
->ops
->release_xprt(xprt
, task
);
1956 if (xprt
->ops
->release_request
)
1957 xprt
->ops
->release_request(task
);
1958 xprt_schedule_autodisconnect(xprt
);
1959 spin_unlock(&xprt
->transport_lock
);
1961 xprt
->ops
->buf_free(task
);
1962 xdr_free_bvec(&req
->rq_rcv_buf
);
1963 xdr_free_bvec(&req
->rq_snd_buf
);
1964 if (req
->rq_cred
!= NULL
)
1965 put_rpccred(req
->rq_cred
);
1966 if (req
->rq_release_snd_buf
)
1967 req
->rq_release_snd_buf(req
);
1969 task
->tk_rqstp
= NULL
;
1970 if (likely(!bc_prealloc(req
)))
1971 xprt
->ops
->free_slot(xprt
, req
);
1973 xprt_free_bc_request(req
);
1976 #ifdef CONFIG_SUNRPC_BACKCHANNEL
1978 xprt_init_bc_request(struct rpc_rqst
*req
, struct rpc_task
*task
)
1980 struct xdr_buf
*xbufp
= &req
->rq_snd_buf
;
1982 task
->tk_rqstp
= req
;
1983 req
->rq_task
= task
;
1984 xprt_init_connect_cookie(req
, req
->rq_xprt
);
1986 * Set up the xdr_buf length.
1987 * This also indicates that the buffer is XDR encoded already.
1989 xbufp
->len
= xbufp
->head
[0].iov_len
+ xbufp
->page_len
+
1990 xbufp
->tail
[0].iov_len
;
1994 static void xprt_init(struct rpc_xprt
*xprt
, struct net
*net
)
1996 kref_init(&xprt
->kref
);
1998 spin_lock_init(&xprt
->transport_lock
);
1999 spin_lock_init(&xprt
->reserve_lock
);
2000 spin_lock_init(&xprt
->queue_lock
);
2002 INIT_LIST_HEAD(&xprt
->free
);
2003 xprt
->recv_queue
= RB_ROOT
;
2004 INIT_LIST_HEAD(&xprt
->xmit_queue
);
2005 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2006 spin_lock_init(&xprt
->bc_pa_lock
);
2007 INIT_LIST_HEAD(&xprt
->bc_pa_list
);
2008 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2009 INIT_LIST_HEAD(&xprt
->xprt_switch
);
2011 xprt
->last_used
= jiffies
;
2012 xprt
->cwnd
= RPC_INITCWND
;
2013 xprt
->bind_index
= 0;
2015 rpc_init_wait_queue(&xprt
->binding
, "xprt_binding");
2016 rpc_init_wait_queue(&xprt
->pending
, "xprt_pending");
2017 rpc_init_wait_queue(&xprt
->sending
, "xprt_sending");
2018 rpc_init_priority_wait_queue(&xprt
->backlog
, "xprt_backlog");
2020 xprt_init_xid(xprt
);
2022 xprt
->xprt_net
= get_net(net
);
2026 * xprt_create_transport - create an RPC transport
2027 * @args: rpc transport creation arguments
2030 struct rpc_xprt
*xprt_create_transport(struct xprt_create
*args
)
2032 struct rpc_xprt
*xprt
;
2033 const struct xprt_class
*t
;
2035 t
= xprt_class_find_by_ident(args
->ident
);
2037 dprintk("RPC: transport (%d) not supported\n", args
->ident
);
2038 return ERR_PTR(-EIO
);
2041 xprt
= t
->setup(args
);
2042 xprt_class_release(t
);
2046 if (args
->flags
& XPRT_CREATE_NO_IDLE_TIMEOUT
)
2047 xprt
->idle_timeout
= 0;
2048 INIT_WORK(&xprt
->task_cleanup
, xprt_autoclose
);
2049 if (xprt_has_timer(xprt
))
2050 timer_setup(&xprt
->timer
, xprt_init_autodisconnect
, 0);
2052 timer_setup(&xprt
->timer
, NULL
, 0);
2054 if (strlen(args
->servername
) > RPC_MAXNETNAMELEN
) {
2056 return ERR_PTR(-EINVAL
);
2058 xprt
->servername
= kstrdup(args
->servername
, GFP_KERNEL
);
2059 if (xprt
->servername
== NULL
) {
2061 return ERR_PTR(-ENOMEM
);
2064 rpc_xprt_debugfs_register(xprt
);
2066 trace_xprt_create(xprt
);
2071 static void xprt_destroy_cb(struct work_struct
*work
)
2073 struct rpc_xprt
*xprt
=
2074 container_of(work
, struct rpc_xprt
, task_cleanup
);
2076 trace_xprt_destroy(xprt
);
2078 rpc_xprt_debugfs_unregister(xprt
);
2079 rpc_destroy_wait_queue(&xprt
->binding
);
2080 rpc_destroy_wait_queue(&xprt
->pending
);
2081 rpc_destroy_wait_queue(&xprt
->sending
);
2082 rpc_destroy_wait_queue(&xprt
->backlog
);
2083 kfree(xprt
->servername
);
2085 * Destroy any existing back channel
2087 xprt_destroy_backchannel(xprt
, UINT_MAX
);
2090 * Tear down transport state and free the rpc_xprt
2092 xprt
->ops
->destroy(xprt
);
2096 * xprt_destroy - destroy an RPC transport, killing off all requests.
2097 * @xprt: transport to destroy
2100 static void xprt_destroy(struct rpc_xprt
*xprt
)
2103 * Exclude transport connect/disconnect handlers and autoclose
2105 wait_on_bit_lock(&xprt
->state
, XPRT_LOCKED
, TASK_UNINTERRUPTIBLE
);
2108 * xprt_schedule_autodisconnect() can run after XPRT_LOCKED
2109 * is cleared. We use ->transport_lock to ensure the mod_timer()
2110 * can only run *before* del_time_sync(), never after.
2112 spin_lock(&xprt
->transport_lock
);
2113 del_timer_sync(&xprt
->timer
);
2114 spin_unlock(&xprt
->transport_lock
);
2117 * Destroy sockets etc from the system workqueue so they can
2118 * safely flush receive work running on rpciod.
2120 INIT_WORK(&xprt
->task_cleanup
, xprt_destroy_cb
);
2121 schedule_work(&xprt
->task_cleanup
);
2124 static void xprt_destroy_kref(struct kref
*kref
)
2126 xprt_destroy(container_of(kref
, struct rpc_xprt
, kref
));
2130 * xprt_get - return a reference to an RPC transport.
2131 * @xprt: pointer to the transport
2134 struct rpc_xprt
*xprt_get(struct rpc_xprt
*xprt
)
2136 if (xprt
!= NULL
&& kref_get_unless_zero(&xprt
->kref
))
2140 EXPORT_SYMBOL_GPL(xprt_get
);
2143 * xprt_put - release a reference to an RPC transport.
2144 * @xprt: pointer to the transport
2147 void xprt_put(struct rpc_xprt
*xprt
)
2150 kref_put(&xprt
->kref
, xprt_destroy_kref
);
2152 EXPORT_SYMBOL_GPL(xprt_put
);