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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sunrpc/xprt.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/sunrpc/xprt.c')
-rw-r--r--net/sunrpc/xprt.c1678
1 files changed, 1678 insertions, 0 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
new file mode 100644
index 000000000000..c74a6bb94074
--- /dev/null
+++ b/net/sunrpc/xprt.c
@@ -0,0 +1,1678 @@
1/*
2 * linux/net/sunrpc/xprt.c
3 *
4 * This is a generic RPC call interface supporting congestion avoidance,
5 * and asynchronous calls.
6 *
7 * The interface works like this:
8 *
9 * - When a process places a call, it allocates a request slot if
10 * one is available. Otherwise, it sleeps on the backlog queue
11 * (xprt_reserve).
12 * - Next, the caller puts together the RPC message, stuffs it into
13 * the request struct, and calls xprt_call().
14 * - xprt_call transmits the message and installs the caller on the
15 * socket'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 socket. 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
23 * of -ETIMEDOUT.
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
28 * again.
29 *
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.
33 *
34 * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
35 *
36 * TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
37 * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
38 * TCP NFS related read + write fixes
39 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
40 *
41 * Rewrite of larges part of the code in order to stabilize TCP stuff.
42 * Fix behaviour when socket buffer is full.
43 * (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
44 */
45
46#include <linux/types.h>
47#include <linux/slab.h>
48#include <linux/capability.h>
49#include <linux/sched.h>
50#include <linux/errno.h>
51#include <linux/socket.h>
52#include <linux/in.h>
53#include <linux/net.h>
54#include <linux/mm.h>
55#include <linux/udp.h>
56#include <linux/tcp.h>
57#include <linux/sunrpc/clnt.h>
58#include <linux/file.h>
59#include <linux/workqueue.h>
60#include <linux/random.h>
61
62#include <net/sock.h>
63#include <net/checksum.h>
64#include <net/udp.h>
65#include <net/tcp.h>
66
67/*
68 * Local variables
69 */
70
71#ifdef RPC_DEBUG
72# undef RPC_DEBUG_DATA
73# define RPCDBG_FACILITY RPCDBG_XPRT
74#endif
75
76#define XPRT_MAX_BACKOFF (8)
77#define XPRT_IDLE_TIMEOUT (5*60*HZ)
78#define XPRT_MAX_RESVPORT (800)
79
80/*
81 * Local functions
82 */
83static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
84static inline void do_xprt_reserve(struct rpc_task *);
85static void xprt_disconnect(struct rpc_xprt *);
86static void xprt_connect_status(struct rpc_task *task);
87static struct rpc_xprt * xprt_setup(int proto, struct sockaddr_in *ap,
88 struct rpc_timeout *to);
89static struct socket *xprt_create_socket(struct rpc_xprt *, int, int);
90static void xprt_bind_socket(struct rpc_xprt *, struct socket *);
91static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
92
93static int xprt_clear_backlog(struct rpc_xprt *xprt);
94
95#ifdef RPC_DEBUG_DATA
96/*
97 * Print the buffer contents (first 128 bytes only--just enough for
98 * diropres return).
99 */
100static void
101xprt_pktdump(char *msg, u32 *packet, unsigned int count)
102{
103 u8 *buf = (u8 *) packet;
104 int j;
105
106 dprintk("RPC: %s\n", msg);
107 for (j = 0; j < count && j < 128; j += 4) {
108 if (!(j & 31)) {
109 if (j)
110 dprintk("\n");
111 dprintk("0x%04x ", j);
112 }
113 dprintk("%02x%02x%02x%02x ",
114 buf[j], buf[j+1], buf[j+2], buf[j+3]);
115 }
116 dprintk("\n");
117}
118#else
119static inline void
120xprt_pktdump(char *msg, u32 *packet, unsigned int count)
121{
122 /* NOP */
123}
124#endif
125
126/*
127 * Look up RPC transport given an INET socket
128 */
129static inline struct rpc_xprt *
130xprt_from_sock(struct sock *sk)
131{
132 return (struct rpc_xprt *) sk->sk_user_data;
133}
134
135/*
136 * Serialize write access to sockets, in order to prevent different
137 * requests from interfering with each other.
138 * Also prevents TCP socket connects from colliding with writes.
139 */
140static int
141__xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
142{
143 struct rpc_rqst *req = task->tk_rqstp;
144
145 if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate)) {
146 if (task == xprt->snd_task)
147 return 1;
148 if (task == NULL)
149 return 0;
150 goto out_sleep;
151 }
152 if (xprt->nocong || __xprt_get_cong(xprt, task)) {
153 xprt->snd_task = task;
154 if (req) {
155 req->rq_bytes_sent = 0;
156 req->rq_ntrans++;
157 }
158 return 1;
159 }
160 smp_mb__before_clear_bit();
161 clear_bit(XPRT_LOCKED, &xprt->sockstate);
162 smp_mb__after_clear_bit();
163out_sleep:
164 dprintk("RPC: %4d failed to lock socket %p\n", task->tk_pid, xprt);
165 task->tk_timeout = 0;
166 task->tk_status = -EAGAIN;
167 if (req && req->rq_ntrans)
168 rpc_sleep_on(&xprt->resend, task, NULL, NULL);
169 else
170 rpc_sleep_on(&xprt->sending, task, NULL, NULL);
171 return 0;
172}
173
174static inline int
175xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
176{
177 int retval;
178
179 spin_lock_bh(&xprt->sock_lock);
180 retval = __xprt_lock_write(xprt, task);
181 spin_unlock_bh(&xprt->sock_lock);
182 return retval;
183}
184
185
186static void
187__xprt_lock_write_next(struct rpc_xprt *xprt)
188{
189 struct rpc_task *task;
190
191 if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate))
192 return;
193 if (!xprt->nocong && RPCXPRT_CONGESTED(xprt))
194 goto out_unlock;
195 task = rpc_wake_up_next(&xprt->resend);
196 if (!task) {
197 task = rpc_wake_up_next(&xprt->sending);
198 if (!task)
199 goto out_unlock;
200 }
201 if (xprt->nocong || __xprt_get_cong(xprt, task)) {
202 struct rpc_rqst *req = task->tk_rqstp;
203 xprt->snd_task = task;
204 if (req) {
205 req->rq_bytes_sent = 0;
206 req->rq_ntrans++;
207 }
208 return;
209 }
210out_unlock:
211 smp_mb__before_clear_bit();
212 clear_bit(XPRT_LOCKED, &xprt->sockstate);
213 smp_mb__after_clear_bit();
214}
215
216/*
217 * Releases the socket for use by other requests.
218 */
219static void
220__xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
221{
222 if (xprt->snd_task == task) {
223 xprt->snd_task = NULL;
224 smp_mb__before_clear_bit();
225 clear_bit(XPRT_LOCKED, &xprt->sockstate);
226 smp_mb__after_clear_bit();
227 __xprt_lock_write_next(xprt);
228 }
229}
230
231static inline void
232xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
233{
234 spin_lock_bh(&xprt->sock_lock);
235 __xprt_release_write(xprt, task);
236 spin_unlock_bh(&xprt->sock_lock);
237}
238
239/*
240 * Write data to socket.
241 */
242static inline int
243xprt_sendmsg(struct rpc_xprt *xprt, struct rpc_rqst *req)
244{
245 struct socket *sock = xprt->sock;
246 struct xdr_buf *xdr = &req->rq_snd_buf;
247 struct sockaddr *addr = NULL;
248 int addrlen = 0;
249 unsigned int skip;
250 int result;
251
252 if (!sock)
253 return -ENOTCONN;
254
255 xprt_pktdump("packet data:",
256 req->rq_svec->iov_base,
257 req->rq_svec->iov_len);
258
259 /* For UDP, we need to provide an address */
260 if (!xprt->stream) {
261 addr = (struct sockaddr *) &xprt->addr;
262 addrlen = sizeof(xprt->addr);
263 }
264 /* Dont repeat bytes */
265 skip = req->rq_bytes_sent;
266
267 clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
268 result = xdr_sendpages(sock, addr, addrlen, xdr, skip, MSG_DONTWAIT);
269
270 dprintk("RPC: xprt_sendmsg(%d) = %d\n", xdr->len - skip, result);
271
272 if (result >= 0)
273 return result;
274
275 switch (result) {
276 case -ECONNREFUSED:
277 /* When the server has died, an ICMP port unreachable message
278 * prompts ECONNREFUSED.
279 */
280 case -EAGAIN:
281 break;
282 case -ECONNRESET:
283 case -ENOTCONN:
284 case -EPIPE:
285 /* connection broken */
286 if (xprt->stream)
287 result = -ENOTCONN;
288 break;
289 default:
290 printk(KERN_NOTICE "RPC: sendmsg returned error %d\n", -result);
291 }
292 return result;
293}
294
295/*
296 * Van Jacobson congestion avoidance. Check if the congestion window
297 * overflowed. Put the task to sleep if this is the case.
298 */
299static int
300__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
301{
302 struct rpc_rqst *req = task->tk_rqstp;
303
304 if (req->rq_cong)
305 return 1;
306 dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n",
307 task->tk_pid, xprt->cong, xprt->cwnd);
308 if (RPCXPRT_CONGESTED(xprt))
309 return 0;
310 req->rq_cong = 1;
311 xprt->cong += RPC_CWNDSCALE;
312 return 1;
313}
314
315/*
316 * Adjust the congestion window, and wake up the next task
317 * that has been sleeping due to congestion
318 */
319static void
320__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
321{
322 if (!req->rq_cong)
323 return;
324 req->rq_cong = 0;
325 xprt->cong -= RPC_CWNDSCALE;
326 __xprt_lock_write_next(xprt);
327}
328
329/*
330 * Adjust RPC congestion window
331 * We use a time-smoothed congestion estimator to avoid heavy oscillation.
332 */
333static void
334xprt_adjust_cwnd(struct rpc_xprt *xprt, int result)
335{
336 unsigned long cwnd;
337
338 cwnd = xprt->cwnd;
339 if (result >= 0 && cwnd <= xprt->cong) {
340 /* The (cwnd >> 1) term makes sure
341 * the result gets rounded properly. */
342 cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
343 if (cwnd > RPC_MAXCWND(xprt))
344 cwnd = RPC_MAXCWND(xprt);
345 __xprt_lock_write_next(xprt);
346 } else if (result == -ETIMEDOUT) {
347 cwnd >>= 1;
348 if (cwnd < RPC_CWNDSCALE)
349 cwnd = RPC_CWNDSCALE;
350 }
351 dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
352 xprt->cong, xprt->cwnd, cwnd);
353 xprt->cwnd = cwnd;
354}
355
356/*
357 * Reset the major timeout value
358 */
359static void xprt_reset_majortimeo(struct rpc_rqst *req)
360{
361 struct rpc_timeout *to = &req->rq_xprt->timeout;
362
363 req->rq_majortimeo = req->rq_timeout;
364 if (to->to_exponential)
365 req->rq_majortimeo <<= to->to_retries;
366 else
367 req->rq_majortimeo += to->to_increment * to->to_retries;
368 if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
369 req->rq_majortimeo = to->to_maxval;
370 req->rq_majortimeo += jiffies;
371}
372
373/*
374 * Adjust timeout values etc for next retransmit
375 */
376int xprt_adjust_timeout(struct rpc_rqst *req)
377{
378 struct rpc_xprt *xprt = req->rq_xprt;
379 struct rpc_timeout *to = &xprt->timeout;
380 int status = 0;
381
382 if (time_before(jiffies, req->rq_majortimeo)) {
383 if (to->to_exponential)
384 req->rq_timeout <<= 1;
385 else
386 req->rq_timeout += to->to_increment;
387 if (to->to_maxval && req->rq_timeout >= to->to_maxval)
388 req->rq_timeout = to->to_maxval;
389 req->rq_retries++;
390 pprintk("RPC: %lu retrans\n", jiffies);
391 } else {
392 req->rq_timeout = to->to_initval;
393 req->rq_retries = 0;
394 xprt_reset_majortimeo(req);
395 /* Reset the RTT counters == "slow start" */
396 spin_lock_bh(&xprt->sock_lock);
397 rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
398 spin_unlock_bh(&xprt->sock_lock);
399 pprintk("RPC: %lu timeout\n", jiffies);
400 status = -ETIMEDOUT;
401 }
402
403 if (req->rq_timeout == 0) {
404 printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
405 req->rq_timeout = 5 * HZ;
406 }
407 return status;
408}
409
410/*
411 * Close down a transport socket
412 */
413static void
414xprt_close(struct rpc_xprt *xprt)
415{
416 struct socket *sock = xprt->sock;
417 struct sock *sk = xprt->inet;
418
419 if (!sk)
420 return;
421
422 write_lock_bh(&sk->sk_callback_lock);
423 xprt->inet = NULL;
424 xprt->sock = NULL;
425
426 sk->sk_user_data = NULL;
427 sk->sk_data_ready = xprt->old_data_ready;
428 sk->sk_state_change = xprt->old_state_change;
429 sk->sk_write_space = xprt->old_write_space;
430 write_unlock_bh(&sk->sk_callback_lock);
431
432 sk->sk_no_check = 0;
433
434 sock_release(sock);
435}
436
437static void
438xprt_socket_autoclose(void *args)
439{
440 struct rpc_xprt *xprt = (struct rpc_xprt *)args;
441
442 xprt_disconnect(xprt);
443 xprt_close(xprt);
444 xprt_release_write(xprt, NULL);
445}
446
447/*
448 * Mark a transport as disconnected
449 */
450static void
451xprt_disconnect(struct rpc_xprt *xprt)
452{
453 dprintk("RPC: disconnected transport %p\n", xprt);
454 spin_lock_bh(&xprt->sock_lock);
455 xprt_clear_connected(xprt);
456 rpc_wake_up_status(&xprt->pending, -ENOTCONN);
457 spin_unlock_bh(&xprt->sock_lock);
458}
459
460/*
461 * Used to allow disconnection when we've been idle
462 */
463static void
464xprt_init_autodisconnect(unsigned long data)
465{
466 struct rpc_xprt *xprt = (struct rpc_xprt *)data;
467
468 spin_lock(&xprt->sock_lock);
469 if (!list_empty(&xprt->recv) || xprt->shutdown)
470 goto out_abort;
471 if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate))
472 goto out_abort;
473 spin_unlock(&xprt->sock_lock);
474 /* Let keventd close the socket */
475 if (test_bit(XPRT_CONNECTING, &xprt->sockstate) != 0)
476 xprt_release_write(xprt, NULL);
477 else
478 schedule_work(&xprt->task_cleanup);
479 return;
480out_abort:
481 spin_unlock(&xprt->sock_lock);
482}
483
484static void xprt_socket_connect(void *args)
485{
486 struct rpc_xprt *xprt = (struct rpc_xprt *)args;
487 struct socket *sock = xprt->sock;
488 int status = -EIO;
489
490 if (xprt->shutdown || xprt->addr.sin_port == 0)
491 goto out;
492
493 /*
494 * Start by resetting any existing state
495 */
496 xprt_close(xprt);
497 sock = xprt_create_socket(xprt, xprt->prot, xprt->resvport);
498 if (sock == NULL) {
499 /* couldn't create socket or bind to reserved port;
500 * this is likely a permanent error, so cause an abort */
501 goto out;
502 }
503 xprt_bind_socket(xprt, sock);
504 xprt_sock_setbufsize(xprt);
505
506 status = 0;
507 if (!xprt->stream)
508 goto out;
509
510 /*
511 * Tell the socket layer to start connecting...
512 */
513 status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
514 sizeof(xprt->addr), O_NONBLOCK);
515 dprintk("RPC: %p connect status %d connected %d sock state %d\n",
516 xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
517 if (status < 0) {
518 switch (status) {
519 case -EINPROGRESS:
520 case -EALREADY:
521 goto out_clear;
522 }
523 }
524out:
525 if (status < 0)
526 rpc_wake_up_status(&xprt->pending, status);
527 else
528 rpc_wake_up(&xprt->pending);
529out_clear:
530 smp_mb__before_clear_bit();
531 clear_bit(XPRT_CONNECTING, &xprt->sockstate);
532 smp_mb__after_clear_bit();
533}
534
535/*
536 * Attempt to connect a TCP socket.
537 *
538 */
539void xprt_connect(struct rpc_task *task)
540{
541 struct rpc_xprt *xprt = task->tk_xprt;
542
543 dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid,
544 xprt, (xprt_connected(xprt) ? "is" : "is not"));
545
546 if (xprt->shutdown) {
547 task->tk_status = -EIO;
548 return;
549 }
550 if (!xprt->addr.sin_port) {
551 task->tk_status = -EIO;
552 return;
553 }
554 if (!xprt_lock_write(xprt, task))
555 return;
556 if (xprt_connected(xprt))
557 goto out_write;
558
559 if (task->tk_rqstp)
560 task->tk_rqstp->rq_bytes_sent = 0;
561
562 task->tk_timeout = RPC_CONNECT_TIMEOUT;
563 rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL);
564 if (!test_and_set_bit(XPRT_CONNECTING, &xprt->sockstate)) {
565 /* Note: if we are here due to a dropped connection
566 * we delay reconnecting by RPC_REESTABLISH_TIMEOUT/HZ
567 * seconds
568 */
569 if (xprt->sock != NULL)
570 schedule_delayed_work(&xprt->sock_connect,
571 RPC_REESTABLISH_TIMEOUT);
572 else
573 schedule_work(&xprt->sock_connect);
574 }
575 return;
576 out_write:
577 xprt_release_write(xprt, task);
578}
579
580/*
581 * We arrive here when awoken from waiting on connection establishment.
582 */
583static void
584xprt_connect_status(struct rpc_task *task)
585{
586 struct rpc_xprt *xprt = task->tk_xprt;
587
588 if (task->tk_status >= 0) {
589 dprintk("RPC: %4d xprt_connect_status: connection established\n",
590 task->tk_pid);
591 return;
592 }
593
594 /* if soft mounted, just cause this RPC to fail */
595 if (RPC_IS_SOFT(task))
596 task->tk_status = -EIO;
597
598 switch (task->tk_status) {
599 case -ECONNREFUSED:
600 case -ECONNRESET:
601 case -ENOTCONN:
602 return;
603 case -ETIMEDOUT:
604 dprintk("RPC: %4d xprt_connect_status: timed out\n",
605 task->tk_pid);
606 break;
607 default:
608 printk(KERN_ERR "RPC: error %d connecting to server %s\n",
609 -task->tk_status, task->tk_client->cl_server);
610 }
611 xprt_release_write(xprt, task);
612}
613
614/*
615 * Look up the RPC request corresponding to a reply, and then lock it.
616 */
617static inline struct rpc_rqst *
618xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid)
619{
620 struct list_head *pos;
621 struct rpc_rqst *req = NULL;
622
623 list_for_each(pos, &xprt->recv) {
624 struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list);
625 if (entry->rq_xid == xid) {
626 req = entry;
627 break;
628 }
629 }
630 return req;
631}
632
633/*
634 * Complete reply received.
635 * The TCP code relies on us to remove the request from xprt->pending.
636 */
637static void
638xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
639{
640 struct rpc_task *task = req->rq_task;
641 struct rpc_clnt *clnt = task->tk_client;
642
643 /* Adjust congestion window */
644 if (!xprt->nocong) {
645 unsigned timer = task->tk_msg.rpc_proc->p_timer;
646 xprt_adjust_cwnd(xprt, copied);
647 __xprt_put_cong(xprt, req);
648 if (timer) {
649 if (req->rq_ntrans == 1)
650 rpc_update_rtt(clnt->cl_rtt, timer,
651 (long)jiffies - req->rq_xtime);
652 rpc_set_timeo(clnt->cl_rtt, timer, req->rq_ntrans - 1);
653 }
654 }
655
656#ifdef RPC_PROFILE
657 /* Profile only reads for now */
658 if (copied > 1024) {
659 static unsigned long nextstat;
660 static unsigned long pkt_rtt, pkt_len, pkt_cnt;
661
662 pkt_cnt++;
663 pkt_len += req->rq_slen + copied;
664 pkt_rtt += jiffies - req->rq_xtime;
665 if (time_before(nextstat, jiffies)) {
666 printk("RPC: %lu %ld cwnd\n", jiffies, xprt->cwnd);
667 printk("RPC: %ld %ld %ld %ld stat\n",
668 jiffies, pkt_cnt, pkt_len, pkt_rtt);
669 pkt_rtt = pkt_len = pkt_cnt = 0;
670 nextstat = jiffies + 5 * HZ;
671 }
672 }
673#endif
674
675 dprintk("RPC: %4d has input (%d bytes)\n", task->tk_pid, copied);
676 list_del_init(&req->rq_list);
677 req->rq_received = req->rq_private_buf.len = copied;
678
679 /* ... and wake up the process. */
680 rpc_wake_up_task(task);
681 return;
682}
683
684static size_t
685skb_read_bits(skb_reader_t *desc, void *to, size_t len)
686{
687 if (len > desc->count)
688 len = desc->count;
689 if (skb_copy_bits(desc->skb, desc->offset, to, len))
690 return 0;
691 desc->count -= len;
692 desc->offset += len;
693 return len;
694}
695
696static size_t
697skb_read_and_csum_bits(skb_reader_t *desc, void *to, size_t len)
698{
699 unsigned int csum2, pos;
700
701 if (len > desc->count)
702 len = desc->count;
703 pos = desc->offset;
704 csum2 = skb_copy_and_csum_bits(desc->skb, pos, to, len, 0);
705 desc->csum = csum_block_add(desc->csum, csum2, pos);
706 desc->count -= len;
707 desc->offset += len;
708 return len;
709}
710
711/*
712 * We have set things up such that we perform the checksum of the UDP
713 * packet in parallel with the copies into the RPC client iovec. -DaveM
714 */
715int
716csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
717{
718 skb_reader_t desc;
719
720 desc.skb = skb;
721 desc.offset = sizeof(struct udphdr);
722 desc.count = skb->len - desc.offset;
723
724 if (skb->ip_summed == CHECKSUM_UNNECESSARY)
725 goto no_checksum;
726
727 desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
728 xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_and_csum_bits);
729 if (desc.offset != skb->len) {
730 unsigned int csum2;
731 csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
732 desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
733 }
734 if (desc.count)
735 return -1;
736 if ((unsigned short)csum_fold(desc.csum))
737 return -1;
738 return 0;
739no_checksum:
740 xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits);
741 if (desc.count)
742 return -1;
743 return 0;
744}
745
746/*
747 * Input handler for RPC replies. Called from a bottom half and hence
748 * atomic.
749 */
750static void
751udp_data_ready(struct sock *sk, int len)
752{
753 struct rpc_task *task;
754 struct rpc_xprt *xprt;
755 struct rpc_rqst *rovr;
756 struct sk_buff *skb;
757 int err, repsize, copied;
758 u32 _xid, *xp;
759
760 read_lock(&sk->sk_callback_lock);
761 dprintk("RPC: udp_data_ready...\n");
762 if (!(xprt = xprt_from_sock(sk))) {
763 printk("RPC: udp_data_ready request not found!\n");
764 goto out;
765 }
766
767 dprintk("RPC: udp_data_ready client %p\n", xprt);
768
769 if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
770 goto out;
771
772 if (xprt->shutdown)
773 goto dropit;
774
775 repsize = skb->len - sizeof(struct udphdr);
776 if (repsize < 4) {
777 printk("RPC: impossible RPC reply size %d!\n", repsize);
778 goto dropit;
779 }
780
781 /* Copy the XID from the skb... */
782 xp = skb_header_pointer(skb, sizeof(struct udphdr),
783 sizeof(_xid), &_xid);
784 if (xp == NULL)
785 goto dropit;
786
787 /* Look up and lock the request corresponding to the given XID */
788 spin_lock(&xprt->sock_lock);
789 rovr = xprt_lookup_rqst(xprt, *xp);
790 if (!rovr)
791 goto out_unlock;
792 task = rovr->rq_task;
793
794 dprintk("RPC: %4d received reply\n", task->tk_pid);
795
796 if ((copied = rovr->rq_private_buf.buflen) > repsize)
797 copied = repsize;
798
799 /* Suck it into the iovec, verify checksum if not done by hw. */
800 if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
801 goto out_unlock;
802
803 /* Something worked... */
804 dst_confirm(skb->dst);
805
806 xprt_complete_rqst(xprt, rovr, copied);
807
808 out_unlock:
809 spin_unlock(&xprt->sock_lock);
810 dropit:
811 skb_free_datagram(sk, skb);
812 out:
813 read_unlock(&sk->sk_callback_lock);
814}
815
816/*
817 * Copy from an skb into memory and shrink the skb.
818 */
819static inline size_t
820tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
821{
822 if (len > desc->count)
823 len = desc->count;
824 if (skb_copy_bits(desc->skb, desc->offset, p, len))
825 return 0;
826 desc->offset += len;
827 desc->count -= len;
828 return len;
829}
830
831/*
832 * TCP read fragment marker
833 */
834static inline void
835tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
836{
837 size_t len, used;
838 char *p;
839
840 p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
841 len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
842 used = tcp_copy_data(desc, p, len);
843 xprt->tcp_offset += used;
844 if (used != len)
845 return;
846 xprt->tcp_reclen = ntohl(xprt->tcp_recm);
847 if (xprt->tcp_reclen & 0x80000000)
848 xprt->tcp_flags |= XPRT_LAST_FRAG;
849 else
850 xprt->tcp_flags &= ~XPRT_LAST_FRAG;
851 xprt->tcp_reclen &= 0x7fffffff;
852 xprt->tcp_flags &= ~XPRT_COPY_RECM;
853 xprt->tcp_offset = 0;
854 /* Sanity check of the record length */
855 if (xprt->tcp_reclen < 4) {
856 printk(KERN_ERR "RPC: Invalid TCP record fragment length\n");
857 xprt_disconnect(xprt);
858 }
859 dprintk("RPC: reading TCP record fragment of length %d\n",
860 xprt->tcp_reclen);
861}
862
863static void
864tcp_check_recm(struct rpc_xprt *xprt)
865{
866 if (xprt->tcp_offset == xprt->tcp_reclen) {
867 xprt->tcp_flags |= XPRT_COPY_RECM;
868 xprt->tcp_offset = 0;
869 if (xprt->tcp_flags & XPRT_LAST_FRAG) {
870 xprt->tcp_flags &= ~XPRT_COPY_DATA;
871 xprt->tcp_flags |= XPRT_COPY_XID;
872 xprt->tcp_copied = 0;
873 }
874 }
875}
876
877/*
878 * TCP read xid
879 */
880static inline void
881tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
882{
883 size_t len, used;
884 char *p;
885
886 len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
887 dprintk("RPC: reading XID (%Zu bytes)\n", len);
888 p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
889 used = tcp_copy_data(desc, p, len);
890 xprt->tcp_offset += used;
891 if (used != len)
892 return;
893 xprt->tcp_flags &= ~XPRT_COPY_XID;
894 xprt->tcp_flags |= XPRT_COPY_DATA;
895 xprt->tcp_copied = 4;
896 dprintk("RPC: reading reply for XID %08x\n",
897 ntohl(xprt->tcp_xid));
898 tcp_check_recm(xprt);
899}
900
901/*
902 * TCP read and complete request
903 */
904static inline void
905tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
906{
907 struct rpc_rqst *req;
908 struct xdr_buf *rcvbuf;
909 size_t len;
910
911 /* Find and lock the request corresponding to this xid */
912 spin_lock(&xprt->sock_lock);
913 req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
914 if (!req) {
915 xprt->tcp_flags &= ~XPRT_COPY_DATA;
916 dprintk("RPC: XID %08x request not found!\n",
917 ntohl(xprt->tcp_xid));
918 spin_unlock(&xprt->sock_lock);
919 return;
920 }
921
922 rcvbuf = &req->rq_private_buf;
923 len = desc->count;
924 if (len > xprt->tcp_reclen - xprt->tcp_offset) {
925 skb_reader_t my_desc;
926
927 len = xprt->tcp_reclen - xprt->tcp_offset;
928 memcpy(&my_desc, desc, sizeof(my_desc));
929 my_desc.count = len;
930 xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
931 &my_desc, tcp_copy_data);
932 desc->count -= len;
933 desc->offset += len;
934 } else
935 xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
936 desc, tcp_copy_data);
937 xprt->tcp_copied += len;
938 xprt->tcp_offset += len;
939
940 if (xprt->tcp_copied == req->rq_private_buf.buflen)
941 xprt->tcp_flags &= ~XPRT_COPY_DATA;
942 else if (xprt->tcp_offset == xprt->tcp_reclen) {
943 if (xprt->tcp_flags & XPRT_LAST_FRAG)
944 xprt->tcp_flags &= ~XPRT_COPY_DATA;
945 }
946
947 if (!(xprt->tcp_flags & XPRT_COPY_DATA)) {
948 dprintk("RPC: %4d received reply complete\n",
949 req->rq_task->tk_pid);
950 xprt_complete_rqst(xprt, req, xprt->tcp_copied);
951 }
952 spin_unlock(&xprt->sock_lock);
953 tcp_check_recm(xprt);
954}
955
956/*
957 * TCP discard extra bytes from a short read
958 */
959static inline void
960tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
961{
962 size_t len;
963
964 len = xprt->tcp_reclen - xprt->tcp_offset;
965 if (len > desc->count)
966 len = desc->count;
967 desc->count -= len;
968 desc->offset += len;
969 xprt->tcp_offset += len;
970 tcp_check_recm(xprt);
971}
972
973/*
974 * TCP record receive routine
975 * We first have to grab the record marker, then the XID, then the data.
976 */
977static int
978tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
979 unsigned int offset, size_t len)
980{
981 struct rpc_xprt *xprt = rd_desc->arg.data;
982 skb_reader_t desc = {
983 .skb = skb,
984 .offset = offset,
985 .count = len,
986 .csum = 0
987 };
988
989 dprintk("RPC: tcp_data_recv\n");
990 do {
991 /* Read in a new fragment marker if necessary */
992 /* Can we ever really expect to get completely empty fragments? */
993 if (xprt->tcp_flags & XPRT_COPY_RECM) {
994 tcp_read_fraghdr(xprt, &desc);
995 continue;
996 }
997 /* Read in the xid if necessary */
998 if (xprt->tcp_flags & XPRT_COPY_XID) {
999 tcp_read_xid(xprt, &desc);
1000 continue;
1001 }
1002 /* Read in the request data */
1003 if (xprt->tcp_flags & XPRT_COPY_DATA) {
1004 tcp_read_request(xprt, &desc);
1005 continue;
1006 }
1007 /* Skip over any trailing bytes on short reads */
1008 tcp_read_discard(xprt, &desc);
1009 } while (desc.count);
1010 dprintk("RPC: tcp_data_recv done\n");
1011 return len - desc.count;
1012}
1013
1014static void tcp_data_ready(struct sock *sk, int bytes)
1015{
1016 struct rpc_xprt *xprt;
1017 read_descriptor_t rd_desc;
1018
1019 read_lock(&sk->sk_callback_lock);
1020 dprintk("RPC: tcp_data_ready...\n");
1021 if (!(xprt = xprt_from_sock(sk))) {
1022 printk("RPC: tcp_data_ready socket info not found!\n");
1023 goto out;
1024 }
1025 if (xprt->shutdown)
1026 goto out;
1027
1028 /* We use rd_desc to pass struct xprt to tcp_data_recv */
1029 rd_desc.arg.data = xprt;
1030 rd_desc.count = 65536;
1031 tcp_read_sock(sk, &rd_desc, tcp_data_recv);
1032out:
1033 read_unlock(&sk->sk_callback_lock);
1034}
1035
1036static void
1037tcp_state_change(struct sock *sk)
1038{
1039 struct rpc_xprt *xprt;
1040
1041 read_lock(&sk->sk_callback_lock);
1042 if (!(xprt = xprt_from_sock(sk)))
1043 goto out;
1044 dprintk("RPC: tcp_state_change client %p...\n", xprt);
1045 dprintk("RPC: state %x conn %d dead %d zapped %d\n",
1046 sk->sk_state, xprt_connected(xprt),
1047 sock_flag(sk, SOCK_DEAD),
1048 sock_flag(sk, SOCK_ZAPPED));
1049
1050 switch (sk->sk_state) {
1051 case TCP_ESTABLISHED:
1052 spin_lock_bh(&xprt->sock_lock);
1053 if (!xprt_test_and_set_connected(xprt)) {
1054 /* Reset TCP record info */
1055 xprt->tcp_offset = 0;
1056 xprt->tcp_reclen = 0;
1057 xprt->tcp_copied = 0;
1058 xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
1059 rpc_wake_up(&xprt->pending);
1060 }
1061 spin_unlock_bh(&xprt->sock_lock);
1062 break;
1063 case TCP_SYN_SENT:
1064 case TCP_SYN_RECV:
1065 break;
1066 default:
1067 if (xprt_test_and_clear_connected(xprt))
1068 rpc_wake_up_status(&xprt->pending, -ENOTCONN);
1069 break;
1070 }
1071 out:
1072 read_unlock(&sk->sk_callback_lock);
1073}
1074
1075/*
1076 * Called when more output buffer space is available for this socket.
1077 * We try not to wake our writers until they can make "significant"
1078 * progress, otherwise we'll waste resources thrashing sock_sendmsg
1079 * with a bunch of small requests.
1080 */
1081static void
1082xprt_write_space(struct sock *sk)
1083{
1084 struct rpc_xprt *xprt;
1085 struct socket *sock;
1086
1087 read_lock(&sk->sk_callback_lock);
1088 if (!(xprt = xprt_from_sock(sk)) || !(sock = sk->sk_socket))
1089 goto out;
1090 if (xprt->shutdown)
1091 goto out;
1092
1093 /* Wait until we have enough socket memory */
1094 if (xprt->stream) {
1095 /* from net/core/stream.c:sk_stream_write_space */
1096 if (sk_stream_wspace(sk) < sk_stream_min_wspace(sk))
1097 goto out;
1098 } else {
1099 /* from net/core/sock.c:sock_def_write_space */
1100 if (!sock_writeable(sk))
1101 goto out;
1102 }
1103
1104 if (!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))
1105 goto out;
1106
1107 spin_lock_bh(&xprt->sock_lock);
1108 if (xprt->snd_task)
1109 rpc_wake_up_task(xprt->snd_task);
1110 spin_unlock_bh(&xprt->sock_lock);
1111out:
1112 read_unlock(&sk->sk_callback_lock);
1113}
1114
1115/*
1116 * RPC receive timeout handler.
1117 */
1118static void
1119xprt_timer(struct rpc_task *task)
1120{
1121 struct rpc_rqst *req = task->tk_rqstp;
1122 struct rpc_xprt *xprt = req->rq_xprt;
1123
1124 spin_lock(&xprt->sock_lock);
1125 if (req->rq_received)
1126 goto out;
1127
1128 xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
1129 __xprt_put_cong(xprt, req);
1130
1131 dprintk("RPC: %4d xprt_timer (%s request)\n",
1132 task->tk_pid, req ? "pending" : "backlogged");
1133
1134 task->tk_status = -ETIMEDOUT;
1135out:
1136 task->tk_timeout = 0;
1137 rpc_wake_up_task(task);
1138 spin_unlock(&xprt->sock_lock);
1139}
1140
1141/*
1142 * Place the actual RPC call.
1143 * We have to copy the iovec because sendmsg fiddles with its contents.
1144 */
1145int
1146xprt_prepare_transmit(struct rpc_task *task)
1147{
1148 struct rpc_rqst *req = task->tk_rqstp;
1149 struct rpc_xprt *xprt = req->rq_xprt;
1150 int err = 0;
1151
1152 dprintk("RPC: %4d xprt_prepare_transmit\n", task->tk_pid);
1153
1154 if (xprt->shutdown)
1155 return -EIO;
1156
1157 spin_lock_bh(&xprt->sock_lock);
1158 if (req->rq_received && !req->rq_bytes_sent) {
1159 err = req->rq_received;
1160 goto out_unlock;
1161 }
1162 if (!__xprt_lock_write(xprt, task)) {
1163 err = -EAGAIN;
1164 goto out_unlock;
1165 }
1166
1167 if (!xprt_connected(xprt)) {
1168 err = -ENOTCONN;
1169 goto out_unlock;
1170 }
1171out_unlock:
1172 spin_unlock_bh(&xprt->sock_lock);
1173 return err;
1174}
1175
1176void
1177xprt_transmit(struct rpc_task *task)
1178{
1179 struct rpc_clnt *clnt = task->tk_client;
1180 struct rpc_rqst *req = task->tk_rqstp;
1181 struct rpc_xprt *xprt = req->rq_xprt;
1182 int status, retry = 0;
1183
1184
1185 dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
1186
1187 /* set up everything as needed. */
1188 /* Write the record marker */
1189 if (xprt->stream) {
1190 u32 *marker = req->rq_svec[0].iov_base;
1191
1192 *marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker)));
1193 }
1194
1195 smp_rmb();
1196 if (!req->rq_received) {
1197 if (list_empty(&req->rq_list)) {
1198 spin_lock_bh(&xprt->sock_lock);
1199 /* Update the softirq receive buffer */
1200 memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
1201 sizeof(req->rq_private_buf));
1202 /* Add request to the receive list */
1203 list_add_tail(&req->rq_list, &xprt->recv);
1204 spin_unlock_bh(&xprt->sock_lock);
1205 xprt_reset_majortimeo(req);
1206 }
1207 } else if (!req->rq_bytes_sent)
1208 return;
1209
1210 /* Continue transmitting the packet/record. We must be careful
1211 * to cope with writespace callbacks arriving _after_ we have
1212 * called xprt_sendmsg().
1213 */
1214 while (1) {
1215 req->rq_xtime = jiffies;
1216 status = xprt_sendmsg(xprt, req);
1217
1218 if (status < 0)
1219 break;
1220
1221 if (xprt->stream) {
1222 req->rq_bytes_sent += status;
1223
1224 /* If we've sent the entire packet, immediately
1225 * reset the count of bytes sent. */
1226 if (req->rq_bytes_sent >= req->rq_slen) {
1227 req->rq_bytes_sent = 0;
1228 goto out_receive;
1229 }
1230 } else {
1231 if (status >= req->rq_slen)
1232 goto out_receive;
1233 status = -EAGAIN;
1234 break;
1235 }
1236
1237 dprintk("RPC: %4d xmit incomplete (%d left of %d)\n",
1238 task->tk_pid, req->rq_slen - req->rq_bytes_sent,
1239 req->rq_slen);
1240
1241 status = -EAGAIN;
1242 if (retry++ > 50)
1243 break;
1244 }
1245
1246 /* Note: at this point, task->tk_sleeping has not yet been set,
1247 * hence there is no danger of the waking up task being put on
1248 * schedq, and being picked up by a parallel run of rpciod().
1249 */
1250 task->tk_status = status;
1251
1252 switch (status) {
1253 case -EAGAIN:
1254 if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
1255 /* Protect against races with xprt_write_space */
1256 spin_lock_bh(&xprt->sock_lock);
1257 /* Don't race with disconnect */
1258 if (!xprt_connected(xprt))
1259 task->tk_status = -ENOTCONN;
1260 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags)) {
1261 task->tk_timeout = req->rq_timeout;
1262 rpc_sleep_on(&xprt->pending, task, NULL, NULL);
1263 }
1264 spin_unlock_bh(&xprt->sock_lock);
1265 return;
1266 }
1267 /* Keep holding the socket if it is blocked */
1268 rpc_delay(task, HZ>>4);
1269 return;
1270 case -ECONNREFUSED:
1271 task->tk_timeout = RPC_REESTABLISH_TIMEOUT;
1272 rpc_sleep_on(&xprt->sending, task, NULL, NULL);
1273 case -ENOTCONN:
1274 return;
1275 default:
1276 if (xprt->stream)
1277 xprt_disconnect(xprt);
1278 }
1279 xprt_release_write(xprt, task);
1280 return;
1281 out_receive:
1282 dprintk("RPC: %4d xmit complete\n", task->tk_pid);
1283 /* Set the task's receive timeout value */
1284 spin_lock_bh(&xprt->sock_lock);
1285 if (!xprt->nocong) {
1286 int timer = task->tk_msg.rpc_proc->p_timer;
1287 task->tk_timeout = rpc_calc_rto(clnt->cl_rtt, timer);
1288 task->tk_timeout <<= rpc_ntimeo(clnt->cl_rtt, timer) + req->rq_retries;
1289 if (task->tk_timeout > xprt->timeout.to_maxval || task->tk_timeout == 0)
1290 task->tk_timeout = xprt->timeout.to_maxval;
1291 } else
1292 task->tk_timeout = req->rq_timeout;
1293 /* Don't race with disconnect */
1294 if (!xprt_connected(xprt))
1295 task->tk_status = -ENOTCONN;
1296 else if (!req->rq_received)
1297 rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer);
1298 __xprt_release_write(xprt, task);
1299 spin_unlock_bh(&xprt->sock_lock);
1300}
1301
1302/*
1303 * Reserve an RPC call slot.
1304 */
1305static inline void
1306do_xprt_reserve(struct rpc_task *task)
1307{
1308 struct rpc_xprt *xprt = task->tk_xprt;
1309
1310 task->tk_status = 0;
1311 if (task->tk_rqstp)
1312 return;
1313 if (!list_empty(&xprt->free)) {
1314 struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
1315 list_del_init(&req->rq_list);
1316 task->tk_rqstp = req;
1317 xprt_request_init(task, xprt);
1318 return;
1319 }
1320 dprintk("RPC: waiting for request slot\n");
1321 task->tk_status = -EAGAIN;
1322 task->tk_timeout = 0;
1323 rpc_sleep_on(&xprt->backlog, task, NULL, NULL);
1324}
1325
1326void
1327xprt_reserve(struct rpc_task *task)
1328{
1329 struct rpc_xprt *xprt = task->tk_xprt;
1330
1331 task->tk_status = -EIO;
1332 if (!xprt->shutdown) {
1333 spin_lock(&xprt->xprt_lock);
1334 do_xprt_reserve(task);
1335 spin_unlock(&xprt->xprt_lock);
1336 if (task->tk_rqstp)
1337 del_timer_sync(&xprt->timer);
1338 }
1339}
1340
1341/*
1342 * Allocate a 'unique' XID
1343 */
1344static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt)
1345{
1346 return xprt->xid++;
1347}
1348
1349static inline void xprt_init_xid(struct rpc_xprt *xprt)
1350{
1351 get_random_bytes(&xprt->xid, sizeof(xprt->xid));
1352}
1353
1354/*
1355 * Initialize RPC request
1356 */
1357static void
1358xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
1359{
1360 struct rpc_rqst *req = task->tk_rqstp;
1361
1362 req->rq_timeout = xprt->timeout.to_initval;
1363 req->rq_task = task;
1364 req->rq_xprt = xprt;
1365 req->rq_xid = xprt_alloc_xid(xprt);
1366 dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid,
1367 req, ntohl(req->rq_xid));
1368}
1369
1370/*
1371 * Release an RPC call slot
1372 */
1373void
1374xprt_release(struct rpc_task *task)
1375{
1376 struct rpc_xprt *xprt = task->tk_xprt;
1377 struct rpc_rqst *req;
1378
1379 if (!(req = task->tk_rqstp))
1380 return;
1381 spin_lock_bh(&xprt->sock_lock);
1382 __xprt_release_write(xprt, task);
1383 __xprt_put_cong(xprt, req);
1384 if (!list_empty(&req->rq_list))
1385 list_del(&req->rq_list);
1386 xprt->last_used = jiffies;
1387 if (list_empty(&xprt->recv) && !xprt->shutdown)
1388 mod_timer(&xprt->timer, xprt->last_used + XPRT_IDLE_TIMEOUT);
1389 spin_unlock_bh(&xprt->sock_lock);
1390 task->tk_rqstp = NULL;
1391 memset(req, 0, sizeof(*req)); /* mark unused */
1392
1393 dprintk("RPC: %4d release request %p\n", task->tk_pid, req);
1394
1395 spin_lock(&xprt->xprt_lock);
1396 list_add(&req->rq_list, &xprt->free);
1397 xprt_clear_backlog(xprt);
1398 spin_unlock(&xprt->xprt_lock);
1399}
1400
1401/*
1402 * Set default timeout parameters
1403 */
1404static void
1405xprt_default_timeout(struct rpc_timeout *to, int proto)
1406{
1407 if (proto == IPPROTO_UDP)
1408 xprt_set_timeout(to, 5, 5 * HZ);
1409 else
1410 xprt_set_timeout(to, 5, 60 * HZ);
1411}
1412
1413/*
1414 * Set constant timeout
1415 */
1416void
1417xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr)
1418{
1419 to->to_initval =
1420 to->to_increment = incr;
1421 to->to_maxval = incr * retr;
1422 to->to_retries = retr;
1423 to->to_exponential = 0;
1424}
1425
1426unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
1427unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
1428
1429/*
1430 * Initialize an RPC client
1431 */
1432static struct rpc_xprt *
1433xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
1434{
1435 struct rpc_xprt *xprt;
1436 unsigned int entries;
1437 size_t slot_table_size;
1438 struct rpc_rqst *req;
1439
1440 dprintk("RPC: setting up %s transport...\n",
1441 proto == IPPROTO_UDP? "UDP" : "TCP");
1442
1443 entries = (proto == IPPROTO_TCP)?
1444 xprt_tcp_slot_table_entries : xprt_udp_slot_table_entries;
1445
1446 if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL)
1447 return ERR_PTR(-ENOMEM);
1448 memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */
1449 xprt->max_reqs = entries;
1450 slot_table_size = entries * sizeof(xprt->slot[0]);
1451 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1452 if (xprt->slot == NULL) {
1453 kfree(xprt);
1454 return ERR_PTR(-ENOMEM);
1455 }
1456 memset(xprt->slot, 0, slot_table_size);
1457
1458 xprt->addr = *ap;
1459 xprt->prot = proto;
1460 xprt->stream = (proto == IPPROTO_TCP)? 1 : 0;
1461 if (xprt->stream) {
1462 xprt->cwnd = RPC_MAXCWND(xprt);
1463 xprt->nocong = 1;
1464 xprt->max_payload = (1U << 31) - 1;
1465 } else {
1466 xprt->cwnd = RPC_INITCWND;
1467 xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1468 }
1469 spin_lock_init(&xprt->sock_lock);
1470 spin_lock_init(&xprt->xprt_lock);
1471 init_waitqueue_head(&xprt->cong_wait);
1472
1473 INIT_LIST_HEAD(&xprt->free);
1474 INIT_LIST_HEAD(&xprt->recv);
1475 INIT_WORK(&xprt->sock_connect, xprt_socket_connect, xprt);
1476 INIT_WORK(&xprt->task_cleanup, xprt_socket_autoclose, xprt);
1477 init_timer(&xprt->timer);
1478 xprt->timer.function = xprt_init_autodisconnect;
1479 xprt->timer.data = (unsigned long) xprt;
1480 xprt->last_used = jiffies;
1481 xprt->port = XPRT_MAX_RESVPORT;
1482
1483 /* Set timeout parameters */
1484 if (to) {
1485 xprt->timeout = *to;
1486 } else
1487 xprt_default_timeout(&xprt->timeout, xprt->prot);
1488
1489 rpc_init_wait_queue(&xprt->pending, "xprt_pending");
1490 rpc_init_wait_queue(&xprt->sending, "xprt_sending");
1491 rpc_init_wait_queue(&xprt->resend, "xprt_resend");
1492 rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
1493
1494 /* initialize free list */
1495 for (req = &xprt->slot[entries-1]; req >= &xprt->slot[0]; req--)
1496 list_add(&req->rq_list, &xprt->free);
1497
1498 xprt_init_xid(xprt);
1499
1500 /* Check whether we want to use a reserved port */
1501 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1502
1503 dprintk("RPC: created transport %p with %u slots\n", xprt,
1504 xprt->max_reqs);
1505
1506 return xprt;
1507}
1508
1509/*
1510 * Bind to a reserved port
1511 */
1512static inline int xprt_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
1513{
1514 struct sockaddr_in myaddr = {
1515 .sin_family = AF_INET,
1516 };
1517 int err, port;
1518
1519 /* Were we already bound to a given port? Try to reuse it */
1520 port = xprt->port;
1521 do {
1522 myaddr.sin_port = htons(port);
1523 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
1524 sizeof(myaddr));
1525 if (err == 0) {
1526 xprt->port = port;
1527 return 0;
1528 }
1529 if (--port == 0)
1530 port = XPRT_MAX_RESVPORT;
1531 } while (err == -EADDRINUSE && port != xprt->port);
1532
1533 printk("RPC: Can't bind to reserved port (%d).\n", -err);
1534 return err;
1535}
1536
1537static void
1538xprt_bind_socket(struct rpc_xprt *xprt, struct socket *sock)
1539{
1540 struct sock *sk = sock->sk;
1541
1542 if (xprt->inet)
1543 return;
1544
1545 write_lock_bh(&sk->sk_callback_lock);
1546 sk->sk_user_data = xprt;
1547 xprt->old_data_ready = sk->sk_data_ready;
1548 xprt->old_state_change = sk->sk_state_change;
1549 xprt->old_write_space = sk->sk_write_space;
1550 if (xprt->prot == IPPROTO_UDP) {
1551 sk->sk_data_ready = udp_data_ready;
1552 sk->sk_no_check = UDP_CSUM_NORCV;
1553 xprt_set_connected(xprt);
1554 } else {
1555 tcp_sk(sk)->nonagle = 1; /* disable Nagle's algorithm */
1556 sk->sk_data_ready = tcp_data_ready;
1557 sk->sk_state_change = tcp_state_change;
1558 xprt_clear_connected(xprt);
1559 }
1560 sk->sk_write_space = xprt_write_space;
1561
1562 /* Reset to new socket */
1563 xprt->sock = sock;
1564 xprt->inet = sk;
1565 write_unlock_bh(&sk->sk_callback_lock);
1566
1567 return;
1568}
1569
1570/*
1571 * Set socket buffer length
1572 */
1573void
1574xprt_sock_setbufsize(struct rpc_xprt *xprt)
1575{
1576 struct sock *sk = xprt->inet;
1577
1578 if (xprt->stream)
1579 return;
1580 if (xprt->rcvsize) {
1581 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1582 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2;
1583 }
1584 if (xprt->sndsize) {
1585 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1586 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
1587 sk->sk_write_space(sk);
1588 }
1589}
1590
1591/*
1592 * Datastream sockets are created here, but xprt_connect will create
1593 * and connect stream sockets.
1594 */
1595static struct socket * xprt_create_socket(struct rpc_xprt *xprt, int proto, int resvport)
1596{
1597 struct socket *sock;
1598 int type, err;
1599
1600 dprintk("RPC: xprt_create_socket(%s %d)\n",
1601 (proto == IPPROTO_UDP)? "udp" : "tcp", proto);
1602
1603 type = (proto == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1604
1605 if ((err = sock_create_kern(PF_INET, type, proto, &sock)) < 0) {
1606 printk("RPC: can't create socket (%d).\n", -err);
1607 return NULL;
1608 }
1609
1610 /* If the caller has the capability, bind to a reserved port */
1611 if (resvport && xprt_bindresvport(xprt, sock) < 0) {
1612 printk("RPC: can't bind to reserved port.\n");
1613 goto failed;
1614 }
1615
1616 return sock;
1617
1618failed:
1619 sock_release(sock);
1620 return NULL;
1621}
1622
1623/*
1624 * Create an RPC client transport given the protocol and peer address.
1625 */
1626struct rpc_xprt *
1627xprt_create_proto(int proto, struct sockaddr_in *sap, struct rpc_timeout *to)
1628{
1629 struct rpc_xprt *xprt;
1630
1631 xprt = xprt_setup(proto, sap, to);
1632 if (IS_ERR(xprt))
1633 dprintk("RPC: xprt_create_proto failed\n");
1634 else
1635 dprintk("RPC: xprt_create_proto created xprt %p\n", xprt);
1636 return xprt;
1637}
1638
1639/*
1640 * Prepare for transport shutdown.
1641 */
1642static void
1643xprt_shutdown(struct rpc_xprt *xprt)
1644{
1645 xprt->shutdown = 1;
1646 rpc_wake_up(&xprt->sending);
1647 rpc_wake_up(&xprt->resend);
1648 rpc_wake_up(&xprt->pending);
1649 rpc_wake_up(&xprt->backlog);
1650 wake_up(&xprt->cong_wait);
1651 del_timer_sync(&xprt->timer);
1652}
1653
1654/*
1655 * Clear the xprt backlog queue
1656 */
1657static int
1658xprt_clear_backlog(struct rpc_xprt *xprt) {
1659 rpc_wake_up_next(&xprt->backlog);
1660 wake_up(&xprt->cong_wait);
1661 return 1;
1662}
1663
1664/*
1665 * Destroy an RPC transport, killing off all requests.
1666 */
1667int
1668xprt_destroy(struct rpc_xprt *xprt)
1669{
1670 dprintk("RPC: destroying transport %p\n", xprt);
1671 xprt_shutdown(xprt);
1672 xprt_disconnect(xprt);
1673 xprt_close(xprt);
1674 kfree(xprt->slot);
1675 kfree(xprt);
1676
1677 return 0;
1678}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-05 01:38:15 -0500