2 * linux/net/sunrpc/xprt.c
4 * This is a generic RPC call interface supporting congestion avoidance,
5 * and asynchronous calls.
7 * The interface works like this:
9 * - When a process places a call, it allocates a request slot if
10 * one is available. Otherwise, it sleeps on the backlog queue
12 * - Next, the caller puts together the RPC message, stuffs it into
13 * the request struct, and calls xprt_transmit().
14 * - xprt_transmit sends the message and installs the caller on the
15 * transport's wait list. At the same time, it installs a timer that
16 * is run after the packet's timeout has expired.
17 * - When a packet arrives, the data_ready handler walks the list of
18 * pending requests for that transport. If a matching XID is found, the
19 * caller is woken up, and the timer removed.
20 * - When no reply arrives within the timeout interval, the timer is
21 * fired by the kernel and runs xprt_timer(). It either adjusts the
22 * timeout values (minor timeout) or wakes up the caller with a status
24 * - When the caller receives a notification from RPC that a reply arrived,
25 * it should release the RPC slot, and process the reply.
26 * If the call timed out, it may choose to retry the operation by
27 * adjusting the initial timeout value, and simply calling rpc_call
30 * Support for async RPC is done through a set of RPC-specific scheduling
31 * primitives that `transparently' work for processes as well as async
32 * tasks that rely on callbacks.
34 * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
36 * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com>
39 #include <linux/module.h>
41 #include <linux/types.h>
42 #include <linux/interrupt.h>
43 #include <linux/workqueue.h>
44 #include <linux/net.h>
46 #include <linux/sunrpc/clnt.h>
47 #include <linux/sunrpc/metrics.h>
54 # define RPCDBG_FACILITY RPCDBG_XPRT
60 static void xprt_request_init(struct rpc_task
*, struct rpc_xprt
*);
61 static inline void do_xprt_reserve(struct rpc_task
*);
62 static void xprt_connect_status(struct rpc_task
*task
);
63 static int __xprt_get_cong(struct rpc_xprt
*, struct rpc_task
*);
65 static DEFINE_SPINLOCK(xprt_list_lock
);
66 static LIST_HEAD(xprt_list
);
69 * The transport code maintains an estimate on the maximum number of out-
70 * standing RPC requests, using a smoothed version of the congestion
71 * avoidance implemented in 44BSD. This is basically the Van Jacobson
72 * congestion algorithm: If a retransmit occurs, the congestion window is
73 * halved; otherwise, it is incremented by 1/cwnd when
75 * - a reply is received and
76 * - a full number of requests are outstanding and
77 * - the congestion window hasn't been updated recently.
79 #define RPC_CWNDSHIFT (8U)
80 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
81 #define RPC_INITCWND RPC_CWNDSCALE
82 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
84 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
87 * xprt_register_transport - register a transport implementation
88 * @transport: transport to register
90 * If a transport implementation is loaded as a kernel module, it can
91 * call this interface to make itself known to the RPC client.
94 * 0: transport successfully registered
95 * -EEXIST: transport already registered
96 * -EINVAL: transport module being unloaded
98 int xprt_register_transport(struct xprt_class
*transport
)
100 struct xprt_class
*t
;
104 spin_lock(&xprt_list_lock
);
105 list_for_each_entry(t
, &xprt_list
, list
) {
106 /* don't register the same transport class twice */
107 if (t
->ident
== transport
->ident
)
112 if (try_module_get(THIS_MODULE
)) {
113 list_add_tail(&transport
->list
, &xprt_list
);
114 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
);
146 module_put(THIS_MODULE
);
153 spin_unlock(&xprt_list_lock
);
156 EXPORT_SYMBOL_GPL(xprt_unregister_transport
);
159 * xprt_reserve_xprt - serialize write access to transports
160 * @task: task that is requesting access to the transport
162 * This prevents mixing the payload of separate requests, and prevents
163 * transport connects from colliding with writes. No congestion control
166 int xprt_reserve_xprt(struct rpc_task
*task
)
168 struct rpc_xprt
*xprt
= task
->tk_xprt
;
169 struct rpc_rqst
*req
= task
->tk_rqstp
;
171 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
)) {
172 if (task
== xprt
->snd_task
)
178 xprt
->snd_task
= task
;
180 req
->rq_bytes_sent
= 0;
186 dprintk("RPC: %5u failed to lock transport %p\n",
188 task
->tk_timeout
= 0;
189 task
->tk_status
= -EAGAIN
;
190 if (req
&& req
->rq_ntrans
)
191 rpc_sleep_on(&xprt
->resend
, task
, NULL
, NULL
);
193 rpc_sleep_on(&xprt
->sending
, task
, NULL
, NULL
);
196 EXPORT_SYMBOL_GPL(xprt_reserve_xprt
);
198 static void xprt_clear_locked(struct rpc_xprt
*xprt
)
200 xprt
->snd_task
= NULL
;
201 if (!test_bit(XPRT_CLOSE_WAIT
, &xprt
->state
) || xprt
->shutdown
) {
202 smp_mb__before_clear_bit();
203 clear_bit(XPRT_LOCKED
, &xprt
->state
);
204 smp_mb__after_clear_bit();
206 queue_work(rpciod_workqueue
, &xprt
->task_cleanup
);
210 * xprt_reserve_xprt_cong - serialize write access to transports
211 * @task: task that is requesting access to the transport
213 * Same as xprt_reserve_xprt, but Van Jacobson congestion control is
214 * integrated into the decision of whether a request is allowed to be
215 * woken up and given access to the transport.
217 int xprt_reserve_xprt_cong(struct rpc_task
*task
)
219 struct rpc_xprt
*xprt
= task
->tk_xprt
;
220 struct rpc_rqst
*req
= task
->tk_rqstp
;
222 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
)) {
223 if (task
== xprt
->snd_task
)
227 if (__xprt_get_cong(xprt
, task
)) {
228 xprt
->snd_task
= task
;
230 req
->rq_bytes_sent
= 0;
235 xprt_clear_locked(xprt
);
237 dprintk("RPC: %5u failed to lock transport %p\n", task
->tk_pid
, xprt
);
238 task
->tk_timeout
= 0;
239 task
->tk_status
= -EAGAIN
;
240 if (req
&& req
->rq_ntrans
)
241 rpc_sleep_on(&xprt
->resend
, task
, NULL
, NULL
);
243 rpc_sleep_on(&xprt
->sending
, task
, NULL
, NULL
);
246 EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong
);
248 static inline int xprt_lock_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
252 spin_lock_bh(&xprt
->transport_lock
);
253 retval
= xprt
->ops
->reserve_xprt(task
);
254 spin_unlock_bh(&xprt
->transport_lock
);
258 static void __xprt_lock_write_next(struct rpc_xprt
*xprt
)
260 struct rpc_task
*task
;
261 struct rpc_rqst
*req
;
263 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
266 task
= rpc_wake_up_next(&xprt
->resend
);
268 task
= rpc_wake_up_next(&xprt
->sending
);
273 req
= task
->tk_rqstp
;
274 xprt
->snd_task
= task
;
276 req
->rq_bytes_sent
= 0;
282 xprt_clear_locked(xprt
);
285 static void __xprt_lock_write_next_cong(struct rpc_xprt
*xprt
)
287 struct rpc_task
*task
;
289 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
291 if (RPCXPRT_CONGESTED(xprt
))
293 task
= rpc_wake_up_next(&xprt
->resend
);
295 task
= rpc_wake_up_next(&xprt
->sending
);
299 if (__xprt_get_cong(xprt
, task
)) {
300 struct rpc_rqst
*req
= task
->tk_rqstp
;
301 xprt
->snd_task
= task
;
303 req
->rq_bytes_sent
= 0;
309 xprt_clear_locked(xprt
);
313 * xprt_release_xprt - allow other requests to use a transport
314 * @xprt: transport with other tasks potentially waiting
315 * @task: task that is releasing access to the transport
317 * Note that "task" can be NULL. No congestion control is provided.
319 void xprt_release_xprt(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
321 if (xprt
->snd_task
== task
) {
322 xprt_clear_locked(xprt
);
323 __xprt_lock_write_next(xprt
);
326 EXPORT_SYMBOL_GPL(xprt_release_xprt
);
329 * xprt_release_xprt_cong - allow other requests to use a transport
330 * @xprt: transport with other tasks potentially waiting
331 * @task: task that is releasing access to the transport
333 * Note that "task" can be NULL. Another task is awoken to use the
334 * transport if the transport's congestion window allows it.
336 void xprt_release_xprt_cong(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
338 if (xprt
->snd_task
== task
) {
339 xprt_clear_locked(xprt
);
340 __xprt_lock_write_next_cong(xprt
);
343 EXPORT_SYMBOL_GPL(xprt_release_xprt_cong
);
345 static inline void xprt_release_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
347 spin_lock_bh(&xprt
->transport_lock
);
348 xprt
->ops
->release_xprt(xprt
, task
);
349 spin_unlock_bh(&xprt
->transport_lock
);
353 * Van Jacobson congestion avoidance. Check if the congestion window
354 * overflowed. Put the task to sleep if this is the case.
357 __xprt_get_cong(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
359 struct rpc_rqst
*req
= task
->tk_rqstp
;
363 dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
364 task
->tk_pid
, xprt
->cong
, xprt
->cwnd
);
365 if (RPCXPRT_CONGESTED(xprt
))
368 xprt
->cong
+= RPC_CWNDSCALE
;
373 * Adjust the congestion window, and wake up the next task
374 * that has been sleeping due to congestion
377 __xprt_put_cong(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
382 xprt
->cong
-= RPC_CWNDSCALE
;
383 __xprt_lock_write_next_cong(xprt
);
387 * xprt_release_rqst_cong - housekeeping when request is complete
388 * @task: RPC request that recently completed
390 * Useful for transports that require congestion control.
392 void xprt_release_rqst_cong(struct rpc_task
*task
)
394 __xprt_put_cong(task
->tk_xprt
, task
->tk_rqstp
);
396 EXPORT_SYMBOL_GPL(xprt_release_rqst_cong
);
399 * xprt_adjust_cwnd - adjust transport congestion window
400 * @task: recently completed RPC request used to adjust window
401 * @result: result code of completed RPC request
403 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
405 void xprt_adjust_cwnd(struct rpc_task
*task
, int result
)
407 struct rpc_rqst
*req
= task
->tk_rqstp
;
408 struct rpc_xprt
*xprt
= task
->tk_xprt
;
409 unsigned long cwnd
= xprt
->cwnd
;
411 if (result
>= 0 && cwnd
<= xprt
->cong
) {
412 /* The (cwnd >> 1) term makes sure
413 * the result gets rounded properly. */
414 cwnd
+= (RPC_CWNDSCALE
* RPC_CWNDSCALE
+ (cwnd
>> 1)) / cwnd
;
415 if (cwnd
> RPC_MAXCWND(xprt
))
416 cwnd
= RPC_MAXCWND(xprt
);
417 __xprt_lock_write_next_cong(xprt
);
418 } else if (result
== -ETIMEDOUT
) {
420 if (cwnd
< RPC_CWNDSCALE
)
421 cwnd
= RPC_CWNDSCALE
;
423 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
424 xprt
->cong
, xprt
->cwnd
, cwnd
);
426 __xprt_put_cong(xprt
, req
);
428 EXPORT_SYMBOL_GPL(xprt_adjust_cwnd
);
431 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
432 * @xprt: transport with waiting tasks
433 * @status: result code to plant in each task before waking it
436 void xprt_wake_pending_tasks(struct rpc_xprt
*xprt
, int status
)
439 rpc_wake_up_status(&xprt
->pending
, status
);
441 rpc_wake_up(&xprt
->pending
);
443 EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks
);
446 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
447 * @task: task to be put to sleep
450 void xprt_wait_for_buffer_space(struct rpc_task
*task
)
452 struct rpc_rqst
*req
= task
->tk_rqstp
;
453 struct rpc_xprt
*xprt
= req
->rq_xprt
;
455 task
->tk_timeout
= req
->rq_timeout
;
456 rpc_sleep_on(&xprt
->pending
, task
, NULL
, NULL
);
458 EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space
);
461 * xprt_write_space - wake the task waiting for transport output buffer space
462 * @xprt: transport with waiting tasks
464 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
466 void xprt_write_space(struct rpc_xprt
*xprt
)
468 if (unlikely(xprt
->shutdown
))
471 spin_lock_bh(&xprt
->transport_lock
);
472 if (xprt
->snd_task
) {
473 dprintk("RPC: write space: waking waiting task on "
475 rpc_wake_up_task(xprt
->snd_task
);
477 spin_unlock_bh(&xprt
->transport_lock
);
479 EXPORT_SYMBOL_GPL(xprt_write_space
);
482 * xprt_set_retrans_timeout_def - set a request's retransmit timeout
483 * @task: task whose timeout is to be set
485 * Set a request's retransmit timeout based on the transport's
486 * default timeout parameters. Used by transports that don't adjust
487 * the retransmit timeout based on round-trip time estimation.
489 void xprt_set_retrans_timeout_def(struct rpc_task
*task
)
491 task
->tk_timeout
= task
->tk_rqstp
->rq_timeout
;
493 EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def
);
496 * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
497 * @task: task whose timeout is to be set
499 * Set a request's retransmit timeout using the RTT estimator.
501 void xprt_set_retrans_timeout_rtt(struct rpc_task
*task
)
503 int timer
= task
->tk_msg
.rpc_proc
->p_timer
;
504 struct rpc_rtt
*rtt
= task
->tk_client
->cl_rtt
;
505 struct rpc_rqst
*req
= task
->tk_rqstp
;
506 unsigned long max_timeout
= req
->rq_xprt
->timeout
.to_maxval
;
508 task
->tk_timeout
= rpc_calc_rto(rtt
, timer
);
509 task
->tk_timeout
<<= rpc_ntimeo(rtt
, timer
) + req
->rq_retries
;
510 if (task
->tk_timeout
> max_timeout
|| task
->tk_timeout
== 0)
511 task
->tk_timeout
= max_timeout
;
513 EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt
);
515 static void xprt_reset_majortimeo(struct rpc_rqst
*req
)
517 struct rpc_timeout
*to
= &req
->rq_xprt
->timeout
;
519 req
->rq_majortimeo
= req
->rq_timeout
;
520 if (to
->to_exponential
)
521 req
->rq_majortimeo
<<= to
->to_retries
;
523 req
->rq_majortimeo
+= to
->to_increment
* to
->to_retries
;
524 if (req
->rq_majortimeo
> to
->to_maxval
|| req
->rq_majortimeo
== 0)
525 req
->rq_majortimeo
= to
->to_maxval
;
526 req
->rq_majortimeo
+= jiffies
;
530 * xprt_adjust_timeout - adjust timeout values for next retransmit
531 * @req: RPC request containing parameters to use for the adjustment
534 int xprt_adjust_timeout(struct rpc_rqst
*req
)
536 struct rpc_xprt
*xprt
= req
->rq_xprt
;
537 struct rpc_timeout
*to
= &xprt
->timeout
;
540 if (time_before(jiffies
, req
->rq_majortimeo
)) {
541 if (to
->to_exponential
)
542 req
->rq_timeout
<<= 1;
544 req
->rq_timeout
+= to
->to_increment
;
545 if (to
->to_maxval
&& req
->rq_timeout
>= to
->to_maxval
)
546 req
->rq_timeout
= to
->to_maxval
;
549 req
->rq_timeout
= to
->to_initval
;
551 xprt_reset_majortimeo(req
);
552 /* Reset the RTT counters == "slow start" */
553 spin_lock_bh(&xprt
->transport_lock
);
554 rpc_init_rtt(req
->rq_task
->tk_client
->cl_rtt
, to
->to_initval
);
555 spin_unlock_bh(&xprt
->transport_lock
);
559 if (req
->rq_timeout
== 0) {
560 printk(KERN_WARNING
"xprt_adjust_timeout: rq_timeout = 0!\n");
561 req
->rq_timeout
= 5 * HZ
;
566 static void xprt_autoclose(struct work_struct
*work
)
568 struct rpc_xprt
*xprt
=
569 container_of(work
, struct rpc_xprt
, task_cleanup
);
571 xprt
->ops
->close(xprt
);
572 clear_bit(XPRT_CLOSE_WAIT
, &xprt
->state
);
573 xprt_release_write(xprt
, NULL
);
577 * xprt_disconnect_done - mark a transport as disconnected
578 * @xprt: transport to flag for disconnect
581 void xprt_disconnect_done(struct rpc_xprt
*xprt
)
583 dprintk("RPC: disconnected transport %p\n", xprt
);
584 spin_lock_bh(&xprt
->transport_lock
);
585 xprt_clear_connected(xprt
);
586 xprt_wake_pending_tasks(xprt
, -ENOTCONN
);
587 spin_unlock_bh(&xprt
->transport_lock
);
589 EXPORT_SYMBOL_GPL(xprt_disconnect_done
);
592 * xprt_force_disconnect - force a transport to disconnect
593 * @xprt: transport to disconnect
596 void xprt_force_disconnect(struct rpc_xprt
*xprt
)
598 /* Don't race with the test_bit() in xprt_clear_locked() */
599 spin_lock_bh(&xprt
->transport_lock
);
600 set_bit(XPRT_CLOSE_WAIT
, &xprt
->state
);
601 /* Try to schedule an autoclose RPC call */
602 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
) == 0)
603 queue_work(rpciod_workqueue
, &xprt
->task_cleanup
);
604 else if (xprt
->snd_task
!= NULL
)
605 rpc_wake_up_task(xprt
->snd_task
);
606 spin_unlock_bh(&xprt
->transport_lock
);
608 EXPORT_SYMBOL_GPL(xprt_force_disconnect
);
611 xprt_init_autodisconnect(unsigned long data
)
613 struct rpc_xprt
*xprt
= (struct rpc_xprt
*)data
;
615 spin_lock(&xprt
->transport_lock
);
616 if (!list_empty(&xprt
->recv
) || xprt
->shutdown
)
618 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
620 spin_unlock(&xprt
->transport_lock
);
621 if (xprt_connecting(xprt
))
622 xprt_release_write(xprt
, NULL
);
624 queue_work(rpciod_workqueue
, &xprt
->task_cleanup
);
627 spin_unlock(&xprt
->transport_lock
);
631 * xprt_connect - schedule a transport connect operation
632 * @task: RPC task that is requesting the connect
635 void xprt_connect(struct rpc_task
*task
)
637 struct rpc_xprt
*xprt
= task
->tk_xprt
;
639 dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task
->tk_pid
,
640 xprt
, (xprt_connected(xprt
) ? "is" : "is not"));
642 if (!xprt_bound(xprt
)) {
643 task
->tk_status
= -EIO
;
646 if (!xprt_lock_write(xprt
, task
))
648 if (xprt_connected(xprt
))
649 xprt_release_write(xprt
, task
);
652 task
->tk_rqstp
->rq_bytes_sent
= 0;
654 task
->tk_timeout
= xprt
->connect_timeout
;
655 rpc_sleep_on(&xprt
->pending
, task
, xprt_connect_status
, NULL
);
656 xprt
->stat
.connect_start
= jiffies
;
657 xprt
->ops
->connect(task
);
662 static void xprt_connect_status(struct rpc_task
*task
)
664 struct rpc_xprt
*xprt
= task
->tk_xprt
;
666 if (task
->tk_status
>= 0) {
667 xprt
->stat
.connect_count
++;
668 xprt
->stat
.connect_time
+= (long)jiffies
- xprt
->stat
.connect_start
;
669 dprintk("RPC: %5u xprt_connect_status: connection established\n",
674 switch (task
->tk_status
) {
677 dprintk("RPC: %5u xprt_connect_status: server %s refused "
678 "connection\n", task
->tk_pid
,
679 task
->tk_client
->cl_server
);
682 dprintk("RPC: %5u xprt_connect_status: connection broken\n",
686 dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
687 "out\n", task
->tk_pid
);
690 dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
691 "server %s\n", task
->tk_pid
, -task
->tk_status
,
692 task
->tk_client
->cl_server
);
693 xprt_release_write(xprt
, task
);
694 task
->tk_status
= -EIO
;
699 * xprt_lookup_rqst - find an RPC request corresponding to an XID
700 * @xprt: transport on which the original request was transmitted
701 * @xid: RPC XID of incoming reply
704 struct rpc_rqst
*xprt_lookup_rqst(struct rpc_xprt
*xprt
, __be32 xid
)
706 struct list_head
*pos
;
708 list_for_each(pos
, &xprt
->recv
) {
709 struct rpc_rqst
*entry
= list_entry(pos
, struct rpc_rqst
, rq_list
);
710 if (entry
->rq_xid
== xid
)
714 dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
716 xprt
->stat
.bad_xids
++;
719 EXPORT_SYMBOL_GPL(xprt_lookup_rqst
);
722 * xprt_update_rtt - update an RPC client's RTT state after receiving a reply
723 * @task: RPC request that recently completed
726 void xprt_update_rtt(struct rpc_task
*task
)
728 struct rpc_rqst
*req
= task
->tk_rqstp
;
729 struct rpc_rtt
*rtt
= task
->tk_client
->cl_rtt
;
730 unsigned timer
= task
->tk_msg
.rpc_proc
->p_timer
;
733 if (req
->rq_ntrans
== 1)
734 rpc_update_rtt(rtt
, timer
,
735 (long)jiffies
- req
->rq_xtime
);
736 rpc_set_timeo(rtt
, timer
, req
->rq_ntrans
- 1);
739 EXPORT_SYMBOL_GPL(xprt_update_rtt
);
742 * xprt_complete_rqst - called when reply processing is complete
743 * @task: RPC request that recently completed
744 * @copied: actual number of bytes received from the transport
746 * Caller holds transport lock.
748 void xprt_complete_rqst(struct rpc_task
*task
, int copied
)
750 struct rpc_rqst
*req
= task
->tk_rqstp
;
752 dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
753 task
->tk_pid
, ntohl(req
->rq_xid
), copied
);
755 task
->tk_xprt
->stat
.recvs
++;
756 task
->tk_rtt
= (long)jiffies
- req
->rq_xtime
;
758 list_del_init(&req
->rq_list
);
759 /* Ensure all writes are done before we update req->rq_received */
761 req
->rq_received
= req
->rq_private_buf
.len
= copied
;
762 rpc_wake_up_task(task
);
764 EXPORT_SYMBOL_GPL(xprt_complete_rqst
);
766 static void xprt_timer(struct rpc_task
*task
)
768 struct rpc_rqst
*req
= task
->tk_rqstp
;
769 struct rpc_xprt
*xprt
= req
->rq_xprt
;
771 dprintk("RPC: %5u xprt_timer\n", task
->tk_pid
);
773 spin_lock(&xprt
->transport_lock
);
774 if (!req
->rq_received
) {
775 if (xprt
->ops
->timer
)
776 xprt
->ops
->timer(task
);
777 task
->tk_status
= -ETIMEDOUT
;
779 task
->tk_timeout
= 0;
780 rpc_wake_up_task(task
);
781 spin_unlock(&xprt
->transport_lock
);
785 * xprt_prepare_transmit - reserve the transport before sending a request
786 * @task: RPC task about to send a request
789 int xprt_prepare_transmit(struct rpc_task
*task
)
791 struct rpc_rqst
*req
= task
->tk_rqstp
;
792 struct rpc_xprt
*xprt
= req
->rq_xprt
;
795 dprintk("RPC: %5u xprt_prepare_transmit\n", task
->tk_pid
);
797 spin_lock_bh(&xprt
->transport_lock
);
798 if (req
->rq_received
&& !req
->rq_bytes_sent
) {
799 err
= req
->rq_received
;
802 if (!xprt
->ops
->reserve_xprt(task
)) {
807 if (!xprt_connected(xprt
)) {
812 spin_unlock_bh(&xprt
->transport_lock
);
816 void xprt_end_transmit(struct rpc_task
*task
)
818 xprt_release_write(task
->tk_xprt
, task
);
822 * xprt_transmit - send an RPC request on a transport
823 * @task: controlling RPC task
825 * We have to copy the iovec because sendmsg fiddles with its contents.
827 void xprt_transmit(struct rpc_task
*task
)
829 struct rpc_rqst
*req
= task
->tk_rqstp
;
830 struct rpc_xprt
*xprt
= req
->rq_xprt
;
833 dprintk("RPC: %5u xprt_transmit(%u)\n", task
->tk_pid
, req
->rq_slen
);
835 if (!req
->rq_received
) {
836 if (list_empty(&req
->rq_list
)) {
837 spin_lock_bh(&xprt
->transport_lock
);
838 /* Update the softirq receive buffer */
839 memcpy(&req
->rq_private_buf
, &req
->rq_rcv_buf
,
840 sizeof(req
->rq_private_buf
));
841 /* Add request to the receive list */
842 list_add_tail(&req
->rq_list
, &xprt
->recv
);
843 spin_unlock_bh(&xprt
->transport_lock
);
844 xprt_reset_majortimeo(req
);
845 /* Turn off autodisconnect */
846 del_singleshot_timer_sync(&xprt
->timer
);
848 } else if (!req
->rq_bytes_sent
)
851 status
= xprt
->ops
->send_request(task
);
853 dprintk("RPC: %5u xmit complete\n", task
->tk_pid
);
854 spin_lock_bh(&xprt
->transport_lock
);
856 xprt
->ops
->set_retrans_timeout(task
);
859 xprt
->stat
.req_u
+= xprt
->stat
.sends
- xprt
->stat
.recvs
;
860 xprt
->stat
.bklog_u
+= xprt
->backlog
.qlen
;
862 /* Don't race with disconnect */
863 if (!xprt_connected(xprt
))
864 task
->tk_status
= -ENOTCONN
;
865 else if (!req
->rq_received
)
866 rpc_sleep_on(&xprt
->pending
, task
, NULL
, xprt_timer
);
867 spin_unlock_bh(&xprt
->transport_lock
);
871 /* Note: at this point, task->tk_sleeping has not yet been set,
872 * hence there is no danger of the waking up task being put on
873 * schedq, and being picked up by a parallel run of rpciod().
875 task
->tk_status
= status
;
876 if (status
== -ECONNREFUSED
)
877 rpc_sleep_on(&xprt
->sending
, task
, NULL
, NULL
);
880 static inline void do_xprt_reserve(struct rpc_task
*task
)
882 struct rpc_xprt
*xprt
= task
->tk_xprt
;
887 if (!list_empty(&xprt
->free
)) {
888 struct rpc_rqst
*req
= list_entry(xprt
->free
.next
, struct rpc_rqst
, rq_list
);
889 list_del_init(&req
->rq_list
);
890 task
->tk_rqstp
= req
;
891 xprt_request_init(task
, xprt
);
894 dprintk("RPC: waiting for request slot\n");
895 task
->tk_status
= -EAGAIN
;
896 task
->tk_timeout
= 0;
897 rpc_sleep_on(&xprt
->backlog
, task
, NULL
, NULL
);
901 * xprt_reserve - allocate an RPC request slot
902 * @task: RPC task requesting a slot allocation
904 * If no more slots are available, place the task on the transport's
907 void xprt_reserve(struct rpc_task
*task
)
909 struct rpc_xprt
*xprt
= task
->tk_xprt
;
911 task
->tk_status
= -EIO
;
912 spin_lock(&xprt
->reserve_lock
);
913 do_xprt_reserve(task
);
914 spin_unlock(&xprt
->reserve_lock
);
917 static inline __be32
xprt_alloc_xid(struct rpc_xprt
*xprt
)
922 static inline void xprt_init_xid(struct rpc_xprt
*xprt
)
924 xprt
->xid
= net_random();
927 static void xprt_request_init(struct rpc_task
*task
, struct rpc_xprt
*xprt
)
929 struct rpc_rqst
*req
= task
->tk_rqstp
;
931 req
->rq_timeout
= xprt
->timeout
.to_initval
;
934 req
->rq_buffer
= NULL
;
935 req
->rq_xid
= xprt_alloc_xid(xprt
);
936 req
->rq_release_snd_buf
= NULL
;
937 xprt_reset_majortimeo(req
);
938 dprintk("RPC: %5u reserved req %p xid %08x\n", task
->tk_pid
,
939 req
, ntohl(req
->rq_xid
));
943 * xprt_release - release an RPC request slot
944 * @task: task which is finished with the slot
947 void xprt_release(struct rpc_task
*task
)
949 struct rpc_xprt
*xprt
= task
->tk_xprt
;
950 struct rpc_rqst
*req
;
952 if (!(req
= task
->tk_rqstp
))
954 rpc_count_iostats(task
);
955 spin_lock_bh(&xprt
->transport_lock
);
956 xprt
->ops
->release_xprt(xprt
, task
);
957 if (xprt
->ops
->release_request
)
958 xprt
->ops
->release_request(task
);
959 if (!list_empty(&req
->rq_list
))
960 list_del(&req
->rq_list
);
961 xprt
->last_used
= jiffies
;
962 if (list_empty(&xprt
->recv
))
963 mod_timer(&xprt
->timer
,
964 xprt
->last_used
+ xprt
->idle_timeout
);
965 spin_unlock_bh(&xprt
->transport_lock
);
966 xprt
->ops
->buf_free(req
->rq_buffer
);
967 task
->tk_rqstp
= NULL
;
968 if (req
->rq_release_snd_buf
)
969 req
->rq_release_snd_buf(req
);
970 memset(req
, 0, sizeof(*req
)); /* mark unused */
972 dprintk("RPC: %5u release request %p\n", task
->tk_pid
, req
);
974 spin_lock(&xprt
->reserve_lock
);
975 list_add(&req
->rq_list
, &xprt
->free
);
976 rpc_wake_up_next(&xprt
->backlog
);
977 spin_unlock(&xprt
->reserve_lock
);
981 * xprt_set_timeout - set constant RPC timeout
982 * @to: RPC timeout parameters to set up
983 * @retr: number of retries
984 * @incr: amount of increase after each retry
987 void xprt_set_timeout(struct rpc_timeout
*to
, unsigned int retr
, unsigned long incr
)
990 to
->to_increment
= incr
;
991 to
->to_maxval
= to
->to_initval
+ (incr
* retr
);
992 to
->to_retries
= retr
;
993 to
->to_exponential
= 0;
995 EXPORT_SYMBOL_GPL(xprt_set_timeout
);
998 * xprt_create_transport - create an RPC transport
999 * @args: rpc transport creation arguments
1002 struct rpc_xprt
*xprt_create_transport(struct xprt_create
*args
)
1004 struct rpc_xprt
*xprt
;
1005 struct rpc_rqst
*req
;
1006 struct xprt_class
*t
;
1008 spin_lock(&xprt_list_lock
);
1009 list_for_each_entry(t
, &xprt_list
, list
) {
1010 if (t
->ident
== args
->ident
) {
1011 spin_unlock(&xprt_list_lock
);
1015 spin_unlock(&xprt_list_lock
);
1016 printk(KERN_ERR
"RPC: transport (%d) not supported\n", args
->ident
);
1017 return ERR_PTR(-EIO
);
1020 xprt
= t
->setup(args
);
1022 dprintk("RPC: xprt_create_transport: failed, %ld\n",
1027 kref_init(&xprt
->kref
);
1028 spin_lock_init(&xprt
->transport_lock
);
1029 spin_lock_init(&xprt
->reserve_lock
);
1031 INIT_LIST_HEAD(&xprt
->free
);
1032 INIT_LIST_HEAD(&xprt
->recv
);
1033 INIT_WORK(&xprt
->task_cleanup
, xprt_autoclose
);
1034 setup_timer(&xprt
->timer
, xprt_init_autodisconnect
,
1035 (unsigned long)xprt
);
1036 xprt
->last_used
= jiffies
;
1037 xprt
->cwnd
= RPC_INITCWND
;
1038 xprt
->bind_index
= 0;
1040 rpc_init_wait_queue(&xprt
->binding
, "xprt_binding");
1041 rpc_init_wait_queue(&xprt
->pending
, "xprt_pending");
1042 rpc_init_wait_queue(&xprt
->sending
, "xprt_sending");
1043 rpc_init_wait_queue(&xprt
->resend
, "xprt_resend");
1044 rpc_init_priority_wait_queue(&xprt
->backlog
, "xprt_backlog");
1046 /* initialize free list */
1047 for (req
= &xprt
->slot
[xprt
->max_reqs
-1]; req
>= &xprt
->slot
[0]; req
--)
1048 list_add(&req
->rq_list
, &xprt
->free
);
1050 xprt_init_xid(xprt
);
1052 dprintk("RPC: created transport %p with %u slots\n", xprt
,
1059 * xprt_destroy - destroy an RPC transport, killing off all requests.
1060 * @kref: kref for the transport to destroy
1063 static void xprt_destroy(struct kref
*kref
)
1065 struct rpc_xprt
*xprt
= container_of(kref
, struct rpc_xprt
, kref
);
1067 dprintk("RPC: destroying transport %p\n", xprt
);
1069 del_timer_sync(&xprt
->timer
);
1072 * Tear down transport state and free the rpc_xprt
1074 xprt
->ops
->destroy(xprt
);
1078 * xprt_put - release a reference to an RPC transport.
1079 * @xprt: pointer to the transport
1082 void xprt_put(struct rpc_xprt
*xprt
)
1084 kref_put(&xprt
->kref
, xprt_destroy
);
1088 * xprt_get - return a reference to an RPC transport.
1089 * @xprt: pointer to the transport
1092 struct rpc_xprt
*xprt_get(struct rpc_xprt
*xprt
)
1094 kref_get(&xprt
->kref
);