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/random.h>
46 #include <linux/sunrpc/clnt.h>
53 # undef RPC_DEBUG_DATA
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 int xprt_clear_backlog(struct rpc_xprt
*xprt
);
68 * Serialize write access to transports, in order to prevent different
69 * requests from interfering with each other.
70 * Also prevents transport connects from colliding with writes.
73 __xprt_lock_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
75 struct rpc_rqst
*req
= task
->tk_rqstp
;
77 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
)) {
78 if (task
== xprt
->snd_task
)
82 if (xprt
->nocong
|| __xprt_get_cong(xprt
, task
)) {
83 xprt
->snd_task
= task
;
85 req
->rq_bytes_sent
= 0;
90 smp_mb__before_clear_bit();
91 clear_bit(XPRT_LOCKED
, &xprt
->state
);
92 smp_mb__after_clear_bit();
94 dprintk("RPC: %4d failed to lock transport %p\n", task
->tk_pid
, xprt
);
96 task
->tk_status
= -EAGAIN
;
97 if (req
&& req
->rq_ntrans
)
98 rpc_sleep_on(&xprt
->resend
, task
, NULL
, NULL
);
100 rpc_sleep_on(&xprt
->sending
, task
, NULL
, NULL
);
105 xprt_lock_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
109 spin_lock_bh(&xprt
->transport_lock
);
110 retval
= __xprt_lock_write(xprt
, task
);
111 spin_unlock_bh(&xprt
->transport_lock
);
117 __xprt_lock_write_next(struct rpc_xprt
*xprt
)
119 struct rpc_task
*task
;
121 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
123 if (!xprt
->nocong
&& RPCXPRT_CONGESTED(xprt
))
125 task
= rpc_wake_up_next(&xprt
->resend
);
127 task
= rpc_wake_up_next(&xprt
->sending
);
131 if (xprt
->nocong
|| __xprt_get_cong(xprt
, task
)) {
132 struct rpc_rqst
*req
= task
->tk_rqstp
;
133 xprt
->snd_task
= task
;
135 req
->rq_bytes_sent
= 0;
141 smp_mb__before_clear_bit();
142 clear_bit(XPRT_LOCKED
, &xprt
->state
);
143 smp_mb__after_clear_bit();
147 * Releases the transport for use by other requests.
150 __xprt_release_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
152 if (xprt
->snd_task
== task
) {
153 xprt
->snd_task
= NULL
;
154 smp_mb__before_clear_bit();
155 clear_bit(XPRT_LOCKED
, &xprt
->state
);
156 smp_mb__after_clear_bit();
157 __xprt_lock_write_next(xprt
);
162 xprt_release_write(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
164 spin_lock_bh(&xprt
->transport_lock
);
165 __xprt_release_write(xprt
, task
);
166 spin_unlock_bh(&xprt
->transport_lock
);
170 * Van Jacobson congestion avoidance. Check if the congestion window
171 * overflowed. Put the task to sleep if this is the case.
174 __xprt_get_cong(struct rpc_xprt
*xprt
, struct rpc_task
*task
)
176 struct rpc_rqst
*req
= task
->tk_rqstp
;
180 dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n",
181 task
->tk_pid
, xprt
->cong
, xprt
->cwnd
);
182 if (RPCXPRT_CONGESTED(xprt
))
185 xprt
->cong
+= RPC_CWNDSCALE
;
190 * Adjust the congestion window, and wake up the next task
191 * that has been sleeping due to congestion
194 __xprt_put_cong(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
)
199 xprt
->cong
-= RPC_CWNDSCALE
;
200 __xprt_lock_write_next(xprt
);
204 * Adjust RPC congestion window
205 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
208 xprt_adjust_cwnd(struct rpc_xprt
*xprt
, int result
)
213 if (result
>= 0 && cwnd
<= xprt
->cong
) {
214 /* The (cwnd >> 1) term makes sure
215 * the result gets rounded properly. */
216 cwnd
+= (RPC_CWNDSCALE
* RPC_CWNDSCALE
+ (cwnd
>> 1)) / cwnd
;
217 if (cwnd
> RPC_MAXCWND(xprt
))
218 cwnd
= RPC_MAXCWND(xprt
);
219 __xprt_lock_write_next(xprt
);
220 } else if (result
== -ETIMEDOUT
) {
222 if (cwnd
< RPC_CWNDSCALE
)
223 cwnd
= RPC_CWNDSCALE
;
225 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
226 xprt
->cong
, xprt
->cwnd
, cwnd
);
231 * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
232 * @xprt: transport with waiting tasks
233 * @status: result code to plant in each task before waking it
236 void xprt_wake_pending_tasks(struct rpc_xprt
*xprt
, int status
)
239 rpc_wake_up_status(&xprt
->pending
, status
);
241 rpc_wake_up(&xprt
->pending
);
245 * xprt_wait_for_buffer_space - wait for transport output buffer to clear
246 * @task: task to be put to sleep
249 void xprt_wait_for_buffer_space(struct rpc_task
*task
)
251 struct rpc_rqst
*req
= task
->tk_rqstp
;
252 struct rpc_xprt
*xprt
= req
->rq_xprt
;
254 task
->tk_timeout
= req
->rq_timeout
;
255 rpc_sleep_on(&xprt
->pending
, task
, NULL
, NULL
);
259 * xprt_write_space - wake the task waiting for transport output buffer space
260 * @xprt: transport with waiting tasks
262 * Can be called in a soft IRQ context, so xprt_write_space never sleeps.
264 void xprt_write_space(struct rpc_xprt
*xprt
)
266 if (unlikely(xprt
->shutdown
))
269 spin_lock_bh(&xprt
->transport_lock
);
270 if (xprt
->snd_task
) {
271 dprintk("RPC: write space: waking waiting task on xprt %p\n",
273 rpc_wake_up_task(xprt
->snd_task
);
275 spin_unlock_bh(&xprt
->transport_lock
);
278 static void xprt_reset_majortimeo(struct rpc_rqst
*req
)
280 struct rpc_timeout
*to
= &req
->rq_xprt
->timeout
;
282 req
->rq_majortimeo
= req
->rq_timeout
;
283 if (to
->to_exponential
)
284 req
->rq_majortimeo
<<= to
->to_retries
;
286 req
->rq_majortimeo
+= to
->to_increment
* to
->to_retries
;
287 if (req
->rq_majortimeo
> to
->to_maxval
|| req
->rq_majortimeo
== 0)
288 req
->rq_majortimeo
= to
->to_maxval
;
289 req
->rq_majortimeo
+= jiffies
;
293 * xprt_adjust_timeout - adjust timeout values for next retransmit
294 * @req: RPC request containing parameters to use for the adjustment
297 int xprt_adjust_timeout(struct rpc_rqst
*req
)
299 struct rpc_xprt
*xprt
= req
->rq_xprt
;
300 struct rpc_timeout
*to
= &xprt
->timeout
;
303 if (time_before(jiffies
, req
->rq_majortimeo
)) {
304 if (to
->to_exponential
)
305 req
->rq_timeout
<<= 1;
307 req
->rq_timeout
+= to
->to_increment
;
308 if (to
->to_maxval
&& req
->rq_timeout
>= to
->to_maxval
)
309 req
->rq_timeout
= to
->to_maxval
;
311 pprintk("RPC: %lu retrans\n", jiffies
);
313 req
->rq_timeout
= to
->to_initval
;
315 xprt_reset_majortimeo(req
);
316 /* Reset the RTT counters == "slow start" */
317 spin_lock_bh(&xprt
->transport_lock
);
318 rpc_init_rtt(req
->rq_task
->tk_client
->cl_rtt
, to
->to_initval
);
319 spin_unlock_bh(&xprt
->transport_lock
);
320 pprintk("RPC: %lu timeout\n", jiffies
);
324 if (req
->rq_timeout
== 0) {
325 printk(KERN_WARNING
"xprt_adjust_timeout: rq_timeout = 0!\n");
326 req
->rq_timeout
= 5 * HZ
;
331 static void xprt_autoclose(void *args
)
333 struct rpc_xprt
*xprt
= (struct rpc_xprt
*)args
;
335 xprt_disconnect(xprt
);
336 xprt
->ops
->close(xprt
);
337 xprt_release_write(xprt
, NULL
);
341 * xprt_disconnect - mark a transport as disconnected
342 * @xprt: transport to flag for disconnect
345 void xprt_disconnect(struct rpc_xprt
*xprt
)
347 dprintk("RPC: disconnected transport %p\n", xprt
);
348 spin_lock_bh(&xprt
->transport_lock
);
349 xprt_clear_connected(xprt
);
350 xprt_wake_pending_tasks(xprt
, -ENOTCONN
);
351 spin_unlock_bh(&xprt
->transport_lock
);
355 xprt_init_autodisconnect(unsigned long data
)
357 struct rpc_xprt
*xprt
= (struct rpc_xprt
*)data
;
359 spin_lock(&xprt
->transport_lock
);
360 if (!list_empty(&xprt
->recv
) || xprt
->shutdown
)
362 if (test_and_set_bit(XPRT_LOCKED
, &xprt
->state
))
364 spin_unlock(&xprt
->transport_lock
);
365 if (xprt_connecting(xprt
))
366 xprt_release_write(xprt
, NULL
);
368 schedule_work(&xprt
->task_cleanup
);
371 spin_unlock(&xprt
->transport_lock
);
375 * xprt_connect - schedule a transport connect operation
376 * @task: RPC task that is requesting the connect
379 void xprt_connect(struct rpc_task
*task
)
381 struct rpc_xprt
*xprt
= task
->tk_xprt
;
383 dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task
->tk_pid
,
384 xprt
, (xprt_connected(xprt
) ? "is" : "is not"));
386 if (xprt
->shutdown
) {
387 task
->tk_status
= -EIO
;
390 if (!xprt
->addr
.sin_port
) {
391 task
->tk_status
= -EIO
;
394 if (!xprt_lock_write(xprt
, task
))
396 if (xprt_connected(xprt
))
397 xprt_release_write(xprt
, task
);
400 task
->tk_rqstp
->rq_bytes_sent
= 0;
402 task
->tk_timeout
= RPC_CONNECT_TIMEOUT
;
403 rpc_sleep_on(&xprt
->pending
, task
, xprt_connect_status
, NULL
);
404 xprt
->ops
->connect(task
);
409 static void xprt_connect_status(struct rpc_task
*task
)
411 struct rpc_xprt
*xprt
= task
->tk_xprt
;
413 if (task
->tk_status
>= 0) {
414 dprintk("RPC: %4d xprt_connect_status: connection established\n",
419 switch (task
->tk_status
) {
422 dprintk("RPC: %4d xprt_connect_status: server %s refused connection\n",
423 task
->tk_pid
, task
->tk_client
->cl_server
);
426 dprintk("RPC: %4d xprt_connect_status: connection broken\n",
430 dprintk("RPC: %4d xprt_connect_status: connect attempt timed out\n",
434 dprintk("RPC: %4d xprt_connect_status: error %d connecting to server %s\n",
435 task
->tk_pid
, -task
->tk_status
, task
->tk_client
->cl_server
);
436 xprt_release_write(xprt
, task
);
437 task
->tk_status
= -EIO
;
441 /* if soft mounted, just cause this RPC to fail */
442 if (RPC_IS_SOFT(task
)) {
443 xprt_release_write(xprt
, task
);
444 task
->tk_status
= -EIO
;
449 * xprt_lookup_rqst - find an RPC request corresponding to an XID
450 * @xprt: transport on which the original request was transmitted
451 * @xid: RPC XID of incoming reply
454 struct rpc_rqst
*xprt_lookup_rqst(struct rpc_xprt
*xprt
, u32 xid
)
456 struct list_head
*pos
;
457 struct rpc_rqst
*req
= NULL
;
459 list_for_each(pos
, &xprt
->recv
) {
460 struct rpc_rqst
*entry
= list_entry(pos
, struct rpc_rqst
, rq_list
);
461 if (entry
->rq_xid
== xid
) {
470 * xprt_complete_rqst - called when reply processing is complete
471 * @xprt: controlling transport
472 * @req: RPC request that just completed
473 * @copied: actual number of bytes received from the transport
476 void xprt_complete_rqst(struct rpc_xprt
*xprt
, struct rpc_rqst
*req
, int copied
)
478 struct rpc_task
*task
= req
->rq_task
;
479 struct rpc_clnt
*clnt
= task
->tk_client
;
481 /* Adjust congestion window */
483 unsigned timer
= task
->tk_msg
.rpc_proc
->p_timer
;
484 xprt_adjust_cwnd(xprt
, copied
);
485 __xprt_put_cong(xprt
, req
);
487 if (req
->rq_ntrans
== 1)
488 rpc_update_rtt(clnt
->cl_rtt
, timer
,
489 (long)jiffies
- req
->rq_xtime
);
490 rpc_set_timeo(clnt
->cl_rtt
, timer
, req
->rq_ntrans
- 1);
495 /* Profile only reads for now */
497 static unsigned long nextstat
;
498 static unsigned long pkt_rtt
, pkt_len
, pkt_cnt
;
501 pkt_len
+= req
->rq_slen
+ copied
;
502 pkt_rtt
+= jiffies
- req
->rq_xtime
;
503 if (time_before(nextstat
, jiffies
)) {
504 printk("RPC: %lu %ld cwnd\n", jiffies
, xprt
->cwnd
);
505 printk("RPC: %ld %ld %ld %ld stat\n",
506 jiffies
, pkt_cnt
, pkt_len
, pkt_rtt
);
507 pkt_rtt
= pkt_len
= pkt_cnt
= 0;
508 nextstat
= jiffies
+ 5 * HZ
;
513 dprintk("RPC: %4d has input (%d bytes)\n", task
->tk_pid
, copied
);
514 list_del_init(&req
->rq_list
);
515 req
->rq_received
= req
->rq_private_buf
.len
= copied
;
517 /* ... and wake up the process. */
518 rpc_wake_up_task(task
);
523 * RPC receive timeout handler.
526 xprt_timer(struct rpc_task
*task
)
528 struct rpc_rqst
*req
= task
->tk_rqstp
;
529 struct rpc_xprt
*xprt
= req
->rq_xprt
;
531 spin_lock(&xprt
->transport_lock
);
532 if (req
->rq_received
)
535 xprt_adjust_cwnd(req
->rq_xprt
, -ETIMEDOUT
);
536 __xprt_put_cong(xprt
, req
);
538 dprintk("RPC: %4d xprt_timer (%s request)\n",
539 task
->tk_pid
, req
? "pending" : "backlogged");
541 task
->tk_status
= -ETIMEDOUT
;
543 task
->tk_timeout
= 0;
544 rpc_wake_up_task(task
);
545 spin_unlock(&xprt
->transport_lock
);
549 * xprt_prepare_transmit - reserve the transport before sending a request
550 * @task: RPC task about to send a request
553 int xprt_prepare_transmit(struct rpc_task
*task
)
555 struct rpc_rqst
*req
= task
->tk_rqstp
;
556 struct rpc_xprt
*xprt
= req
->rq_xprt
;
559 dprintk("RPC: %4d xprt_prepare_transmit\n", task
->tk_pid
);
564 spin_lock_bh(&xprt
->transport_lock
);
565 if (req
->rq_received
&& !req
->rq_bytes_sent
) {
566 err
= req
->rq_received
;
569 if (!__xprt_lock_write(xprt
, task
)) {
574 if (!xprt_connected(xprt
)) {
579 spin_unlock_bh(&xprt
->transport_lock
);
584 * xprt_transmit - send an RPC request on a transport
585 * @task: controlling RPC task
587 * We have to copy the iovec because sendmsg fiddles with its contents.
589 void xprt_transmit(struct rpc_task
*task
)
591 struct rpc_clnt
*clnt
= task
->tk_client
;
592 struct rpc_rqst
*req
= task
->tk_rqstp
;
593 struct rpc_xprt
*xprt
= req
->rq_xprt
;
596 dprintk("RPC: %4d xprt_transmit(%u)\n", task
->tk_pid
, req
->rq_slen
);
599 if (!req
->rq_received
) {
600 if (list_empty(&req
->rq_list
)) {
601 spin_lock_bh(&xprt
->transport_lock
);
602 /* Update the softirq receive buffer */
603 memcpy(&req
->rq_private_buf
, &req
->rq_rcv_buf
,
604 sizeof(req
->rq_private_buf
));
605 /* Add request to the receive list */
606 list_add_tail(&req
->rq_list
, &xprt
->recv
);
607 spin_unlock_bh(&xprt
->transport_lock
);
608 xprt_reset_majortimeo(req
);
609 /* Turn off autodisconnect */
610 del_singleshot_timer_sync(&xprt
->timer
);
612 } else if (!req
->rq_bytes_sent
)
615 status
= xprt
->ops
->send_request(task
);
619 /* Note: at this point, task->tk_sleeping has not yet been set,
620 * hence there is no danger of the waking up task being put on
621 * schedq, and being picked up by a parallel run of rpciod().
623 task
->tk_status
= status
;
627 task
->tk_timeout
= RPC_REESTABLISH_TIMEOUT
;
628 rpc_sleep_on(&xprt
->sending
, task
, NULL
, NULL
);
635 xprt_release_write(xprt
, task
);
638 dprintk("RPC: %4d xmit complete\n", task
->tk_pid
);
639 /* Set the task's receive timeout value */
640 spin_lock_bh(&xprt
->transport_lock
);
642 int timer
= task
->tk_msg
.rpc_proc
->p_timer
;
643 task
->tk_timeout
= rpc_calc_rto(clnt
->cl_rtt
, timer
);
644 task
->tk_timeout
<<= rpc_ntimeo(clnt
->cl_rtt
, timer
) + req
->rq_retries
;
645 if (task
->tk_timeout
> xprt
->timeout
.to_maxval
|| task
->tk_timeout
== 0)
646 task
->tk_timeout
= xprt
->timeout
.to_maxval
;
648 task
->tk_timeout
= req
->rq_timeout
;
649 /* Don't race with disconnect */
650 if (!xprt_connected(xprt
))
651 task
->tk_status
= -ENOTCONN
;
652 else if (!req
->rq_received
)
653 rpc_sleep_on(&xprt
->pending
, task
, NULL
, xprt_timer
);
654 __xprt_release_write(xprt
, task
);
655 spin_unlock_bh(&xprt
->transport_lock
);
658 static inline void do_xprt_reserve(struct rpc_task
*task
)
660 struct rpc_xprt
*xprt
= task
->tk_xprt
;
665 if (!list_empty(&xprt
->free
)) {
666 struct rpc_rqst
*req
= list_entry(xprt
->free
.next
, struct rpc_rqst
, rq_list
);
667 list_del_init(&req
->rq_list
);
668 task
->tk_rqstp
= req
;
669 xprt_request_init(task
, xprt
);
672 dprintk("RPC: waiting for request slot\n");
673 task
->tk_status
= -EAGAIN
;
674 task
->tk_timeout
= 0;
675 rpc_sleep_on(&xprt
->backlog
, task
, NULL
, NULL
);
679 * xprt_reserve - allocate an RPC request slot
680 * @task: RPC task requesting a slot allocation
682 * If no more slots are available, place the task on the transport's
685 void xprt_reserve(struct rpc_task
*task
)
687 struct rpc_xprt
*xprt
= task
->tk_xprt
;
689 task
->tk_status
= -EIO
;
690 if (!xprt
->shutdown
) {
691 spin_lock(&xprt
->reserve_lock
);
692 do_xprt_reserve(task
);
693 spin_unlock(&xprt
->reserve_lock
);
697 static inline u32
xprt_alloc_xid(struct rpc_xprt
*xprt
)
702 static inline void xprt_init_xid(struct rpc_xprt
*xprt
)
704 get_random_bytes(&xprt
->xid
, sizeof(xprt
->xid
));
707 static void xprt_request_init(struct rpc_task
*task
, struct rpc_xprt
*xprt
)
709 struct rpc_rqst
*req
= task
->tk_rqstp
;
711 req
->rq_timeout
= xprt
->timeout
.to_initval
;
714 req
->rq_xid
= xprt_alloc_xid(xprt
);
715 dprintk("RPC: %4d reserved req %p xid %08x\n", task
->tk_pid
,
716 req
, ntohl(req
->rq_xid
));
720 * xprt_release - release an RPC request slot
721 * @task: task which is finished with the slot
724 void xprt_release(struct rpc_task
*task
)
726 struct rpc_xprt
*xprt
= task
->tk_xprt
;
727 struct rpc_rqst
*req
;
729 if (!(req
= task
->tk_rqstp
))
731 spin_lock_bh(&xprt
->transport_lock
);
732 __xprt_release_write(xprt
, task
);
733 __xprt_put_cong(xprt
, req
);
734 if (!list_empty(&req
->rq_list
))
735 list_del(&req
->rq_list
);
736 xprt
->last_used
= jiffies
;
737 if (list_empty(&xprt
->recv
) && !xprt
->shutdown
)
738 mod_timer(&xprt
->timer
,
739 xprt
->last_used
+ RPC_IDLE_DISCONNECT_TIMEOUT
);
740 spin_unlock_bh(&xprt
->transport_lock
);
741 task
->tk_rqstp
= NULL
;
742 memset(req
, 0, sizeof(*req
)); /* mark unused */
744 dprintk("RPC: %4d release request %p\n", task
->tk_pid
, req
);
746 spin_lock(&xprt
->reserve_lock
);
747 list_add(&req
->rq_list
, &xprt
->free
);
748 xprt_clear_backlog(xprt
);
749 spin_unlock(&xprt
->reserve_lock
);
753 * xprt_set_timeout - set constant RPC timeout
754 * @to: RPC timeout parameters to set up
755 * @retr: number of retries
756 * @incr: amount of increase after each retry
759 void xprt_set_timeout(struct rpc_timeout
*to
, unsigned int retr
, unsigned long incr
)
762 to
->to_increment
= incr
;
763 to
->to_maxval
= to
->to_initval
+ (incr
* retr
);
764 to
->to_retries
= retr
;
765 to
->to_exponential
= 0;
768 static struct rpc_xprt
*xprt_setup(int proto
, struct sockaddr_in
*ap
, struct rpc_timeout
*to
)
771 struct rpc_xprt
*xprt
;
772 struct rpc_rqst
*req
;
774 if ((xprt
= kmalloc(sizeof(struct rpc_xprt
), GFP_KERNEL
)) == NULL
)
775 return ERR_PTR(-ENOMEM
);
776 memset(xprt
, 0, sizeof(*xprt
)); /* Nnnngh! */
782 result
= xs_setup_udp(xprt
, to
);
785 result
= xs_setup_tcp(xprt
, to
);
788 printk(KERN_ERR
"RPC: unrecognized transport protocol: %d\n",
795 return ERR_PTR(result
);
798 spin_lock_init(&xprt
->transport_lock
);
799 spin_lock_init(&xprt
->reserve_lock
);
800 init_waitqueue_head(&xprt
->cong_wait
);
802 INIT_LIST_HEAD(&xprt
->free
);
803 INIT_LIST_HEAD(&xprt
->recv
);
804 INIT_WORK(&xprt
->task_cleanup
, xprt_autoclose
, xprt
);
805 init_timer(&xprt
->timer
);
806 xprt
->timer
.function
= xprt_init_autodisconnect
;
807 xprt
->timer
.data
= (unsigned long) xprt
;
808 xprt
->last_used
= jiffies
;
810 rpc_init_wait_queue(&xprt
->pending
, "xprt_pending");
811 rpc_init_wait_queue(&xprt
->sending
, "xprt_sending");
812 rpc_init_wait_queue(&xprt
->resend
, "xprt_resend");
813 rpc_init_priority_wait_queue(&xprt
->backlog
, "xprt_backlog");
815 /* initialize free list */
816 for (req
= &xprt
->slot
[xprt
->max_reqs
-1]; req
>= &xprt
->slot
[0]; req
--)
817 list_add(&req
->rq_list
, &xprt
->free
);
821 dprintk("RPC: created transport %p with %u slots\n", xprt
,
828 * xprt_create_proto - create an RPC client transport
829 * @proto: requested transport protocol
830 * @sap: remote peer's address
831 * @to: timeout parameters for new transport
834 struct rpc_xprt
*xprt_create_proto(int proto
, struct sockaddr_in
*sap
, struct rpc_timeout
*to
)
836 struct rpc_xprt
*xprt
;
838 xprt
= xprt_setup(proto
, sap
, to
);
840 dprintk("RPC: xprt_create_proto failed\n");
842 dprintk("RPC: xprt_create_proto created xprt %p\n", xprt
);
846 static void xprt_shutdown(struct rpc_xprt
*xprt
)
849 rpc_wake_up(&xprt
->sending
);
850 rpc_wake_up(&xprt
->resend
);
851 xprt_wake_pending_tasks(xprt
, -EIO
);
852 rpc_wake_up(&xprt
->backlog
);
853 wake_up(&xprt
->cong_wait
);
854 del_timer_sync(&xprt
->timer
);
857 static int xprt_clear_backlog(struct rpc_xprt
*xprt
) {
858 rpc_wake_up_next(&xprt
->backlog
);
859 wake_up(&xprt
->cong_wait
);
864 * xprt_destroy - destroy an RPC transport, killing off all requests.
865 * @xprt: transport to destroy
868 int xprt_destroy(struct rpc_xprt
*xprt
)
870 dprintk("RPC: destroying transport %p\n", xprt
);
872 xprt
->ops
->destroy(xprt
);