at91: at91sam9g45 family: identify several chip versions
[linux-2.6/next.git] / net / sunrpc / svc_xprt.c
blobdf124f78ee489762f4a9028af3b95f38a90f34d3
1 /*
2 * linux/net/sunrpc/svc_xprt.c
4 * Author: Tom Tucker <tom@opengridcomputing.com>
5 */
7 #include <linux/sched.h>
8 #include <linux/smp_lock.h>
9 #include <linux/errno.h>
10 #include <linux/freezer.h>
11 #include <linux/kthread.h>
12 #include <net/sock.h>
13 #include <linux/sunrpc/stats.h>
14 #include <linux/sunrpc/svc_xprt.h>
15 #include <linux/sunrpc/svcsock.h>
17 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
19 #define SVC_MAX_WAKING 5
21 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
22 static int svc_deferred_recv(struct svc_rqst *rqstp);
23 static struct cache_deferred_req *svc_defer(struct cache_req *req);
24 static void svc_age_temp_xprts(unsigned long closure);
26 /* apparently the "standard" is that clients close
27 * idle connections after 5 minutes, servers after
28 * 6 minutes
29 * http://www.connectathon.org/talks96/nfstcp.pdf
31 static int svc_conn_age_period = 6*60;
33 /* List of registered transport classes */
34 static DEFINE_SPINLOCK(svc_xprt_class_lock);
35 static LIST_HEAD(svc_xprt_class_list);
37 /* SMP locking strategy:
39 * svc_pool->sp_lock protects most of the fields of that pool.
40 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
41 * when both need to be taken (rare), svc_serv->sv_lock is first.
42 * BKL protects svc_serv->sv_nrthread.
43 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
44 * and the ->sk_info_authunix cache.
46 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
47 * enqueued multiply. During normal transport processing this bit
48 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
49 * Providers should not manipulate this bit directly.
51 * Some flags can be set to certain values at any time
52 * providing that certain rules are followed:
54 * XPT_CONN, XPT_DATA:
55 * - Can be set or cleared at any time.
56 * - After a set, svc_xprt_enqueue must be called to enqueue
57 * the transport for processing.
58 * - After a clear, the transport must be read/accepted.
59 * If this succeeds, it must be set again.
60 * XPT_CLOSE:
61 * - Can set at any time. It is never cleared.
62 * XPT_DEAD:
63 * - Can only be set while XPT_BUSY is held which ensures
64 * that no other thread will be using the transport or will
65 * try to set XPT_DEAD.
68 int svc_reg_xprt_class(struct svc_xprt_class *xcl)
70 struct svc_xprt_class *cl;
71 int res = -EEXIST;
73 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
75 INIT_LIST_HEAD(&xcl->xcl_list);
76 spin_lock(&svc_xprt_class_lock);
77 /* Make sure there isn't already a class with the same name */
78 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
79 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
80 goto out;
82 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
83 res = 0;
84 out:
85 spin_unlock(&svc_xprt_class_lock);
86 return res;
88 EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
90 void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
92 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
93 spin_lock(&svc_xprt_class_lock);
94 list_del_init(&xcl->xcl_list);
95 spin_unlock(&svc_xprt_class_lock);
97 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
100 * Format the transport list for printing
102 int svc_print_xprts(char *buf, int maxlen)
104 struct list_head *le;
105 char tmpstr[80];
106 int len = 0;
107 buf[0] = '\0';
109 spin_lock(&svc_xprt_class_lock);
110 list_for_each(le, &svc_xprt_class_list) {
111 int slen;
112 struct svc_xprt_class *xcl =
113 list_entry(le, struct svc_xprt_class, xcl_list);
115 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
116 slen = strlen(tmpstr);
117 if (len + slen > maxlen)
118 break;
119 len += slen;
120 strcat(buf, tmpstr);
122 spin_unlock(&svc_xprt_class_lock);
124 return len;
127 static void svc_xprt_free(struct kref *kref)
129 struct svc_xprt *xprt =
130 container_of(kref, struct svc_xprt, xpt_ref);
131 struct module *owner = xprt->xpt_class->xcl_owner;
132 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)
133 && xprt->xpt_auth_cache != NULL)
134 svcauth_unix_info_release(xprt->xpt_auth_cache);
135 xprt->xpt_ops->xpo_free(xprt);
136 module_put(owner);
139 void svc_xprt_put(struct svc_xprt *xprt)
141 kref_put(&xprt->xpt_ref, svc_xprt_free);
143 EXPORT_SYMBOL_GPL(svc_xprt_put);
146 * Called by transport drivers to initialize the transport independent
147 * portion of the transport instance.
149 void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
150 struct svc_serv *serv)
152 memset(xprt, 0, sizeof(*xprt));
153 xprt->xpt_class = xcl;
154 xprt->xpt_ops = xcl->xcl_ops;
155 kref_init(&xprt->xpt_ref);
156 xprt->xpt_server = serv;
157 INIT_LIST_HEAD(&xprt->xpt_list);
158 INIT_LIST_HEAD(&xprt->xpt_ready);
159 INIT_LIST_HEAD(&xprt->xpt_deferred);
160 mutex_init(&xprt->xpt_mutex);
161 spin_lock_init(&xprt->xpt_lock);
162 set_bit(XPT_BUSY, &xprt->xpt_flags);
163 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
165 EXPORT_SYMBOL_GPL(svc_xprt_init);
167 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
168 struct svc_serv *serv,
169 const int family,
170 const unsigned short port,
171 int flags)
173 struct sockaddr_in sin = {
174 .sin_family = AF_INET,
175 .sin_addr.s_addr = htonl(INADDR_ANY),
176 .sin_port = htons(port),
178 struct sockaddr_in6 sin6 = {
179 .sin6_family = AF_INET6,
180 .sin6_addr = IN6ADDR_ANY_INIT,
181 .sin6_port = htons(port),
183 struct sockaddr *sap;
184 size_t len;
186 switch (family) {
187 case PF_INET:
188 sap = (struct sockaddr *)&sin;
189 len = sizeof(sin);
190 break;
191 case PF_INET6:
192 sap = (struct sockaddr *)&sin6;
193 len = sizeof(sin6);
194 break;
195 default:
196 return ERR_PTR(-EAFNOSUPPORT);
199 return xcl->xcl_ops->xpo_create(serv, sap, len, flags);
202 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
203 const int family, const unsigned short port,
204 int flags)
206 struct svc_xprt_class *xcl;
208 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
209 spin_lock(&svc_xprt_class_lock);
210 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
211 struct svc_xprt *newxprt;
213 if (strcmp(xprt_name, xcl->xcl_name))
214 continue;
216 if (!try_module_get(xcl->xcl_owner))
217 goto err;
219 spin_unlock(&svc_xprt_class_lock);
220 newxprt = __svc_xpo_create(xcl, serv, family, port, flags);
221 if (IS_ERR(newxprt)) {
222 module_put(xcl->xcl_owner);
223 return PTR_ERR(newxprt);
226 clear_bit(XPT_TEMP, &newxprt->xpt_flags);
227 spin_lock_bh(&serv->sv_lock);
228 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
229 spin_unlock_bh(&serv->sv_lock);
230 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
231 return svc_xprt_local_port(newxprt);
233 err:
234 spin_unlock(&svc_xprt_class_lock);
235 dprintk("svc: transport %s not found\n", xprt_name);
236 return -ENOENT;
238 EXPORT_SYMBOL_GPL(svc_create_xprt);
241 * Copy the local and remote xprt addresses to the rqstp structure
243 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
245 struct sockaddr *sin;
247 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
248 rqstp->rq_addrlen = xprt->xpt_remotelen;
251 * Destination address in request is needed for binding the
252 * source address in RPC replies/callbacks later.
254 sin = (struct sockaddr *)&xprt->xpt_local;
255 switch (sin->sa_family) {
256 case AF_INET:
257 rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
258 break;
259 case AF_INET6:
260 rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
261 break;
264 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
267 * svc_print_addr - Format rq_addr field for printing
268 * @rqstp: svc_rqst struct containing address to print
269 * @buf: target buffer for formatted address
270 * @len: length of target buffer
273 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
275 return __svc_print_addr(svc_addr(rqstp), buf, len);
277 EXPORT_SYMBOL_GPL(svc_print_addr);
280 * Queue up an idle server thread. Must have pool->sp_lock held.
281 * Note: this is really a stack rather than a queue, so that we only
282 * use as many different threads as we need, and the rest don't pollute
283 * the cache.
285 static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
287 list_add(&rqstp->rq_list, &pool->sp_threads);
291 * Dequeue an nfsd thread. Must have pool->sp_lock held.
293 static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
295 list_del(&rqstp->rq_list);
299 * Queue up a transport with data pending. If there are idle nfsd
300 * processes, wake 'em up.
303 void svc_xprt_enqueue(struct svc_xprt *xprt)
305 struct svc_serv *serv = xprt->xpt_server;
306 struct svc_pool *pool;
307 struct svc_rqst *rqstp;
308 int cpu;
309 int thread_avail;
311 if (!(xprt->xpt_flags &
312 ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
313 return;
315 cpu = get_cpu();
316 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
317 put_cpu();
319 spin_lock_bh(&pool->sp_lock);
321 if (test_bit(XPT_DEAD, &xprt->xpt_flags)) {
322 /* Don't enqueue dead transports */
323 dprintk("svc: transport %p is dead, not enqueued\n", xprt);
324 goto out_unlock;
327 pool->sp_stats.packets++;
329 /* Mark transport as busy. It will remain in this state until
330 * the provider calls svc_xprt_received. We update XPT_BUSY
331 * atomically because it also guards against trying to enqueue
332 * the transport twice.
334 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
335 /* Don't enqueue transport while already enqueued */
336 dprintk("svc: transport %p busy, not enqueued\n", xprt);
337 goto out_unlock;
339 BUG_ON(xprt->xpt_pool != NULL);
340 xprt->xpt_pool = pool;
342 /* Handle pending connection */
343 if (test_bit(XPT_CONN, &xprt->xpt_flags))
344 goto process;
346 /* Handle close in-progress */
347 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
348 goto process;
350 /* Check if we have space to reply to a request */
351 if (!xprt->xpt_ops->xpo_has_wspace(xprt)) {
352 /* Don't enqueue while not enough space for reply */
353 dprintk("svc: no write space, transport %p not enqueued\n",
354 xprt);
355 xprt->xpt_pool = NULL;
356 clear_bit(XPT_BUSY, &xprt->xpt_flags);
357 goto out_unlock;
360 process:
361 /* Work out whether threads are available */
362 thread_avail = !list_empty(&pool->sp_threads); /* threads are asleep */
363 if (pool->sp_nwaking >= SVC_MAX_WAKING) {
364 /* too many threads are runnable and trying to wake up */
365 thread_avail = 0;
366 pool->sp_stats.overloads_avoided++;
369 if (thread_avail) {
370 rqstp = list_entry(pool->sp_threads.next,
371 struct svc_rqst,
372 rq_list);
373 dprintk("svc: transport %p served by daemon %p\n",
374 xprt, rqstp);
375 svc_thread_dequeue(pool, rqstp);
376 if (rqstp->rq_xprt)
377 printk(KERN_ERR
378 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
379 rqstp, rqstp->rq_xprt);
380 rqstp->rq_xprt = xprt;
381 svc_xprt_get(xprt);
382 rqstp->rq_reserved = serv->sv_max_mesg;
383 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
384 rqstp->rq_waking = 1;
385 pool->sp_nwaking++;
386 pool->sp_stats.threads_woken++;
387 BUG_ON(xprt->xpt_pool != pool);
388 wake_up(&rqstp->rq_wait);
389 } else {
390 dprintk("svc: transport %p put into queue\n", xprt);
391 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
392 pool->sp_stats.sockets_queued++;
393 BUG_ON(xprt->xpt_pool != pool);
396 out_unlock:
397 spin_unlock_bh(&pool->sp_lock);
399 EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
402 * Dequeue the first transport. Must be called with the pool->sp_lock held.
404 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
406 struct svc_xprt *xprt;
408 if (list_empty(&pool->sp_sockets))
409 return NULL;
411 xprt = list_entry(pool->sp_sockets.next,
412 struct svc_xprt, xpt_ready);
413 list_del_init(&xprt->xpt_ready);
415 dprintk("svc: transport %p dequeued, inuse=%d\n",
416 xprt, atomic_read(&xprt->xpt_ref.refcount));
418 return xprt;
422 * svc_xprt_received conditionally queues the transport for processing
423 * by another thread. The caller must hold the XPT_BUSY bit and must
424 * not thereafter touch transport data.
426 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
427 * insufficient) data.
429 void svc_xprt_received(struct svc_xprt *xprt)
431 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
432 xprt->xpt_pool = NULL;
433 clear_bit(XPT_BUSY, &xprt->xpt_flags);
434 svc_xprt_enqueue(xprt);
436 EXPORT_SYMBOL_GPL(svc_xprt_received);
439 * svc_reserve - change the space reserved for the reply to a request.
440 * @rqstp: The request in question
441 * @space: new max space to reserve
443 * Each request reserves some space on the output queue of the transport
444 * to make sure the reply fits. This function reduces that reserved
445 * space to be the amount of space used already, plus @space.
448 void svc_reserve(struct svc_rqst *rqstp, int space)
450 space += rqstp->rq_res.head[0].iov_len;
452 if (space < rqstp->rq_reserved) {
453 struct svc_xprt *xprt = rqstp->rq_xprt;
454 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
455 rqstp->rq_reserved = space;
457 svc_xprt_enqueue(xprt);
460 EXPORT_SYMBOL_GPL(svc_reserve);
462 static void svc_xprt_release(struct svc_rqst *rqstp)
464 struct svc_xprt *xprt = rqstp->rq_xprt;
466 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
468 kfree(rqstp->rq_deferred);
469 rqstp->rq_deferred = NULL;
471 svc_free_res_pages(rqstp);
472 rqstp->rq_res.page_len = 0;
473 rqstp->rq_res.page_base = 0;
475 /* Reset response buffer and release
476 * the reservation.
477 * But first, check that enough space was reserved
478 * for the reply, otherwise we have a bug!
480 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
481 printk(KERN_ERR "RPC request reserved %d but used %d\n",
482 rqstp->rq_reserved,
483 rqstp->rq_res.len);
485 rqstp->rq_res.head[0].iov_len = 0;
486 svc_reserve(rqstp, 0);
487 rqstp->rq_xprt = NULL;
489 svc_xprt_put(xprt);
493 * External function to wake up a server waiting for data
494 * This really only makes sense for services like lockd
495 * which have exactly one thread anyway.
497 void svc_wake_up(struct svc_serv *serv)
499 struct svc_rqst *rqstp;
500 unsigned int i;
501 struct svc_pool *pool;
503 for (i = 0; i < serv->sv_nrpools; i++) {
504 pool = &serv->sv_pools[i];
506 spin_lock_bh(&pool->sp_lock);
507 if (!list_empty(&pool->sp_threads)) {
508 rqstp = list_entry(pool->sp_threads.next,
509 struct svc_rqst,
510 rq_list);
511 dprintk("svc: daemon %p woken up.\n", rqstp);
513 svc_thread_dequeue(pool, rqstp);
514 rqstp->rq_xprt = NULL;
516 wake_up(&rqstp->rq_wait);
518 spin_unlock_bh(&pool->sp_lock);
521 EXPORT_SYMBOL_GPL(svc_wake_up);
523 int svc_port_is_privileged(struct sockaddr *sin)
525 switch (sin->sa_family) {
526 case AF_INET:
527 return ntohs(((struct sockaddr_in *)sin)->sin_port)
528 < PROT_SOCK;
529 case AF_INET6:
530 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
531 < PROT_SOCK;
532 default:
533 return 0;
538 * Make sure that we don't have too many active connections. If we have,
539 * something must be dropped. It's not clear what will happen if we allow
540 * "too many" connections, but when dealing with network-facing software,
541 * we have to code defensively. Here we do that by imposing hard limits.
543 * There's no point in trying to do random drop here for DoS
544 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
545 * attacker can easily beat that.
547 * The only somewhat efficient mechanism would be if drop old
548 * connections from the same IP first. But right now we don't even
549 * record the client IP in svc_sock.
551 * single-threaded services that expect a lot of clients will probably
552 * need to set sv_maxconn to override the default value which is based
553 * on the number of threads
555 static void svc_check_conn_limits(struct svc_serv *serv)
557 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
558 (serv->sv_nrthreads+3) * 20;
560 if (serv->sv_tmpcnt > limit) {
561 struct svc_xprt *xprt = NULL;
562 spin_lock_bh(&serv->sv_lock);
563 if (!list_empty(&serv->sv_tempsocks)) {
564 if (net_ratelimit()) {
565 /* Try to help the admin */
566 printk(KERN_NOTICE "%s: too many open "
567 "connections, consider increasing %s\n",
568 serv->sv_name, serv->sv_maxconn ?
569 "the max number of connections." :
570 "the number of threads.");
573 * Always select the oldest connection. It's not fair,
574 * but so is life
576 xprt = list_entry(serv->sv_tempsocks.prev,
577 struct svc_xprt,
578 xpt_list);
579 set_bit(XPT_CLOSE, &xprt->xpt_flags);
580 svc_xprt_get(xprt);
582 spin_unlock_bh(&serv->sv_lock);
584 if (xprt) {
585 svc_xprt_enqueue(xprt);
586 svc_xprt_put(xprt);
592 * Receive the next request on any transport. This code is carefully
593 * organised not to touch any cachelines in the shared svc_serv
594 * structure, only cachelines in the local svc_pool.
596 int svc_recv(struct svc_rqst *rqstp, long timeout)
598 struct svc_xprt *xprt = NULL;
599 struct svc_serv *serv = rqstp->rq_server;
600 struct svc_pool *pool = rqstp->rq_pool;
601 int len, i;
602 int pages;
603 struct xdr_buf *arg;
604 DECLARE_WAITQUEUE(wait, current);
605 long time_left;
607 dprintk("svc: server %p waiting for data (to = %ld)\n",
608 rqstp, timeout);
610 if (rqstp->rq_xprt)
611 printk(KERN_ERR
612 "svc_recv: service %p, transport not NULL!\n",
613 rqstp);
614 if (waitqueue_active(&rqstp->rq_wait))
615 printk(KERN_ERR
616 "svc_recv: service %p, wait queue active!\n",
617 rqstp);
619 /* now allocate needed pages. If we get a failure, sleep briefly */
620 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
621 for (i = 0; i < pages ; i++)
622 while (rqstp->rq_pages[i] == NULL) {
623 struct page *p = alloc_page(GFP_KERNEL);
624 if (!p) {
625 set_current_state(TASK_INTERRUPTIBLE);
626 if (signalled() || kthread_should_stop()) {
627 set_current_state(TASK_RUNNING);
628 return -EINTR;
630 schedule_timeout(msecs_to_jiffies(500));
632 rqstp->rq_pages[i] = p;
634 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
635 BUG_ON(pages >= RPCSVC_MAXPAGES);
637 /* Make arg->head point to first page and arg->pages point to rest */
638 arg = &rqstp->rq_arg;
639 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
640 arg->head[0].iov_len = PAGE_SIZE;
641 arg->pages = rqstp->rq_pages + 1;
642 arg->page_base = 0;
643 /* save at least one page for response */
644 arg->page_len = (pages-2)*PAGE_SIZE;
645 arg->len = (pages-1)*PAGE_SIZE;
646 arg->tail[0].iov_len = 0;
648 try_to_freeze();
649 cond_resched();
650 if (signalled() || kthread_should_stop())
651 return -EINTR;
653 spin_lock_bh(&pool->sp_lock);
654 if (rqstp->rq_waking) {
655 rqstp->rq_waking = 0;
656 pool->sp_nwaking--;
657 BUG_ON(pool->sp_nwaking < 0);
659 xprt = svc_xprt_dequeue(pool);
660 if (xprt) {
661 rqstp->rq_xprt = xprt;
662 svc_xprt_get(xprt);
663 rqstp->rq_reserved = serv->sv_max_mesg;
664 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
665 } else {
666 /* No data pending. Go to sleep */
667 svc_thread_enqueue(pool, rqstp);
670 * We have to be able to interrupt this wait
671 * to bring down the daemons ...
673 set_current_state(TASK_INTERRUPTIBLE);
676 * checking kthread_should_stop() here allows us to avoid
677 * locking and signalling when stopping kthreads that call
678 * svc_recv. If the thread has already been woken up, then
679 * we can exit here without sleeping. If not, then it
680 * it'll be woken up quickly during the schedule_timeout
682 if (kthread_should_stop()) {
683 set_current_state(TASK_RUNNING);
684 spin_unlock_bh(&pool->sp_lock);
685 return -EINTR;
688 add_wait_queue(&rqstp->rq_wait, &wait);
689 spin_unlock_bh(&pool->sp_lock);
691 time_left = schedule_timeout(timeout);
693 try_to_freeze();
695 spin_lock_bh(&pool->sp_lock);
696 remove_wait_queue(&rqstp->rq_wait, &wait);
697 if (!time_left)
698 pool->sp_stats.threads_timedout++;
700 xprt = rqstp->rq_xprt;
701 if (!xprt) {
702 svc_thread_dequeue(pool, rqstp);
703 spin_unlock_bh(&pool->sp_lock);
704 dprintk("svc: server %p, no data yet\n", rqstp);
705 if (signalled() || kthread_should_stop())
706 return -EINTR;
707 else
708 return -EAGAIN;
711 spin_unlock_bh(&pool->sp_lock);
713 len = 0;
714 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
715 struct svc_xprt *newxpt;
716 newxpt = xprt->xpt_ops->xpo_accept(xprt);
717 if (newxpt) {
719 * We know this module_get will succeed because the
720 * listener holds a reference too
722 __module_get(newxpt->xpt_class->xcl_owner);
723 svc_check_conn_limits(xprt->xpt_server);
724 spin_lock_bh(&serv->sv_lock);
725 set_bit(XPT_TEMP, &newxpt->xpt_flags);
726 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
727 serv->sv_tmpcnt++;
728 if (serv->sv_temptimer.function == NULL) {
729 /* setup timer to age temp transports */
730 setup_timer(&serv->sv_temptimer,
731 svc_age_temp_xprts,
732 (unsigned long)serv);
733 mod_timer(&serv->sv_temptimer,
734 jiffies + svc_conn_age_period * HZ);
736 spin_unlock_bh(&serv->sv_lock);
737 svc_xprt_received(newxpt);
739 svc_xprt_received(xprt);
740 } else if (!test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
741 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
742 rqstp, pool->sp_id, xprt,
743 atomic_read(&xprt->xpt_ref.refcount));
744 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
745 if (rqstp->rq_deferred) {
746 svc_xprt_received(xprt);
747 len = svc_deferred_recv(rqstp);
748 } else
749 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
750 dprintk("svc: got len=%d\n", len);
753 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
754 dprintk("svc_recv: found XPT_CLOSE\n");
755 svc_delete_xprt(xprt);
758 /* No data, incomplete (TCP) read, or accept() */
759 if (len == 0 || len == -EAGAIN) {
760 rqstp->rq_res.len = 0;
761 svc_xprt_release(rqstp);
762 return -EAGAIN;
764 clear_bit(XPT_OLD, &xprt->xpt_flags);
766 rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
767 rqstp->rq_chandle.defer = svc_defer;
769 if (serv->sv_stats)
770 serv->sv_stats->netcnt++;
771 return len;
773 EXPORT_SYMBOL_GPL(svc_recv);
776 * Drop request
778 void svc_drop(struct svc_rqst *rqstp)
780 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
781 svc_xprt_release(rqstp);
783 EXPORT_SYMBOL_GPL(svc_drop);
786 * Return reply to client.
788 int svc_send(struct svc_rqst *rqstp)
790 struct svc_xprt *xprt;
791 int len;
792 struct xdr_buf *xb;
794 xprt = rqstp->rq_xprt;
795 if (!xprt)
796 return -EFAULT;
798 /* release the receive skb before sending the reply */
799 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
801 /* calculate over-all length */
802 xb = &rqstp->rq_res;
803 xb->len = xb->head[0].iov_len +
804 xb->page_len +
805 xb->tail[0].iov_len;
807 /* Grab mutex to serialize outgoing data. */
808 mutex_lock(&xprt->xpt_mutex);
809 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
810 len = -ENOTCONN;
811 else
812 len = xprt->xpt_ops->xpo_sendto(rqstp);
813 mutex_unlock(&xprt->xpt_mutex);
814 rpc_wake_up(&xprt->xpt_bc_pending);
815 svc_xprt_release(rqstp);
817 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
818 return 0;
819 return len;
823 * Timer function to close old temporary transports, using
824 * a mark-and-sweep algorithm.
826 static void svc_age_temp_xprts(unsigned long closure)
828 struct svc_serv *serv = (struct svc_serv *)closure;
829 struct svc_xprt *xprt;
830 struct list_head *le, *next;
831 LIST_HEAD(to_be_aged);
833 dprintk("svc_age_temp_xprts\n");
835 if (!spin_trylock_bh(&serv->sv_lock)) {
836 /* busy, try again 1 sec later */
837 dprintk("svc_age_temp_xprts: busy\n");
838 mod_timer(&serv->sv_temptimer, jiffies + HZ);
839 return;
842 list_for_each_safe(le, next, &serv->sv_tempsocks) {
843 xprt = list_entry(le, struct svc_xprt, xpt_list);
845 /* First time through, just mark it OLD. Second time
846 * through, close it. */
847 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
848 continue;
849 if (atomic_read(&xprt->xpt_ref.refcount) > 1
850 || test_bit(XPT_BUSY, &xprt->xpt_flags))
851 continue;
852 svc_xprt_get(xprt);
853 list_move(le, &to_be_aged);
854 set_bit(XPT_CLOSE, &xprt->xpt_flags);
855 set_bit(XPT_DETACHED, &xprt->xpt_flags);
857 spin_unlock_bh(&serv->sv_lock);
859 while (!list_empty(&to_be_aged)) {
860 le = to_be_aged.next;
861 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
862 list_del_init(le);
863 xprt = list_entry(le, struct svc_xprt, xpt_list);
865 dprintk("queuing xprt %p for closing\n", xprt);
867 /* a thread will dequeue and close it soon */
868 svc_xprt_enqueue(xprt);
869 svc_xprt_put(xprt);
872 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
876 * Remove a dead transport
878 void svc_delete_xprt(struct svc_xprt *xprt)
880 struct svc_serv *serv = xprt->xpt_server;
881 struct svc_deferred_req *dr;
883 /* Only do this once */
884 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
885 return;
887 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
888 xprt->xpt_ops->xpo_detach(xprt);
890 spin_lock_bh(&serv->sv_lock);
891 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
892 list_del_init(&xprt->xpt_list);
894 * We used to delete the transport from whichever list
895 * it's sk_xprt.xpt_ready node was on, but we don't actually
896 * need to. This is because the only time we're called
897 * while still attached to a queue, the queue itself
898 * is about to be destroyed (in svc_destroy).
900 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
901 serv->sv_tmpcnt--;
903 for (dr = svc_deferred_dequeue(xprt); dr;
904 dr = svc_deferred_dequeue(xprt)) {
905 svc_xprt_put(xprt);
906 kfree(dr);
909 svc_xprt_put(xprt);
910 spin_unlock_bh(&serv->sv_lock);
913 void svc_close_xprt(struct svc_xprt *xprt)
915 set_bit(XPT_CLOSE, &xprt->xpt_flags);
916 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
917 /* someone else will have to effect the close */
918 return;
920 svc_xprt_get(xprt);
921 svc_delete_xprt(xprt);
922 clear_bit(XPT_BUSY, &xprt->xpt_flags);
923 svc_xprt_put(xprt);
925 EXPORT_SYMBOL_GPL(svc_close_xprt);
927 void svc_close_all(struct list_head *xprt_list)
929 struct svc_xprt *xprt;
930 struct svc_xprt *tmp;
932 list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
933 set_bit(XPT_CLOSE, &xprt->xpt_flags);
934 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) {
935 /* Waiting to be processed, but no threads left,
936 * So just remove it from the waiting list
938 list_del_init(&xprt->xpt_ready);
939 clear_bit(XPT_BUSY, &xprt->xpt_flags);
941 svc_close_xprt(xprt);
946 * Handle defer and revisit of requests
949 static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
951 struct svc_deferred_req *dr =
952 container_of(dreq, struct svc_deferred_req, handle);
953 struct svc_xprt *xprt = dr->xprt;
955 spin_lock(&xprt->xpt_lock);
956 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
957 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
958 spin_unlock(&xprt->xpt_lock);
959 dprintk("revisit canceled\n");
960 svc_xprt_put(xprt);
961 kfree(dr);
962 return;
964 dprintk("revisit queued\n");
965 dr->xprt = NULL;
966 list_add(&dr->handle.recent, &xprt->xpt_deferred);
967 spin_unlock(&xprt->xpt_lock);
968 svc_xprt_enqueue(xprt);
969 svc_xprt_put(xprt);
973 * Save the request off for later processing. The request buffer looks
974 * like this:
976 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
978 * This code can only handle requests that consist of an xprt-header
979 * and rpc-header.
981 static struct cache_deferred_req *svc_defer(struct cache_req *req)
983 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
984 struct svc_deferred_req *dr;
986 if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral)
987 return NULL; /* if more than a page, give up FIXME */
988 if (rqstp->rq_deferred) {
989 dr = rqstp->rq_deferred;
990 rqstp->rq_deferred = NULL;
991 } else {
992 size_t skip;
993 size_t size;
994 /* FIXME maybe discard if size too large */
995 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
996 dr = kmalloc(size, GFP_KERNEL);
997 if (dr == NULL)
998 return NULL;
1000 dr->handle.owner = rqstp->rq_server;
1001 dr->prot = rqstp->rq_prot;
1002 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1003 dr->addrlen = rqstp->rq_addrlen;
1004 dr->daddr = rqstp->rq_daddr;
1005 dr->argslen = rqstp->rq_arg.len >> 2;
1006 dr->xprt_hlen = rqstp->rq_xprt_hlen;
1008 /* back up head to the start of the buffer and copy */
1009 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1010 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1011 dr->argslen << 2);
1013 svc_xprt_get(rqstp->rq_xprt);
1014 dr->xprt = rqstp->rq_xprt;
1016 dr->handle.revisit = svc_revisit;
1017 return &dr->handle;
1021 * recv data from a deferred request into an active one
1023 static int svc_deferred_recv(struct svc_rqst *rqstp)
1025 struct svc_deferred_req *dr = rqstp->rq_deferred;
1027 /* setup iov_base past transport header */
1028 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1029 /* The iov_len does not include the transport header bytes */
1030 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
1031 rqstp->rq_arg.page_len = 0;
1032 /* The rq_arg.len includes the transport header bytes */
1033 rqstp->rq_arg.len = dr->argslen<<2;
1034 rqstp->rq_prot = dr->prot;
1035 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1036 rqstp->rq_addrlen = dr->addrlen;
1037 /* Save off transport header len in case we get deferred again */
1038 rqstp->rq_xprt_hlen = dr->xprt_hlen;
1039 rqstp->rq_daddr = dr->daddr;
1040 rqstp->rq_respages = rqstp->rq_pages;
1041 return (dr->argslen<<2) - dr->xprt_hlen;
1045 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1047 struct svc_deferred_req *dr = NULL;
1049 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1050 return NULL;
1051 spin_lock(&xprt->xpt_lock);
1052 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1053 if (!list_empty(&xprt->xpt_deferred)) {
1054 dr = list_entry(xprt->xpt_deferred.next,
1055 struct svc_deferred_req,
1056 handle.recent);
1057 list_del_init(&dr->handle.recent);
1058 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
1060 spin_unlock(&xprt->xpt_lock);
1061 return dr;
1065 * svc_find_xprt - find an RPC transport instance
1066 * @serv: pointer to svc_serv to search
1067 * @xcl_name: C string containing transport's class name
1068 * @af: Address family of transport's local address
1069 * @port: transport's IP port number
1071 * Return the transport instance pointer for the endpoint accepting
1072 * connections/peer traffic from the specified transport class,
1073 * address family and port.
1075 * Specifying 0 for the address family or port is effectively a
1076 * wild-card, and will result in matching the first transport in the
1077 * service's list that has a matching class name.
1079 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1080 const sa_family_t af, const unsigned short port)
1082 struct svc_xprt *xprt;
1083 struct svc_xprt *found = NULL;
1085 /* Sanity check the args */
1086 if (serv == NULL || xcl_name == NULL)
1087 return found;
1089 spin_lock_bh(&serv->sv_lock);
1090 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1091 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1092 continue;
1093 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1094 continue;
1095 if (port != 0 && port != svc_xprt_local_port(xprt))
1096 continue;
1097 found = xprt;
1098 svc_xprt_get(xprt);
1099 break;
1101 spin_unlock_bh(&serv->sv_lock);
1102 return found;
1104 EXPORT_SYMBOL_GPL(svc_find_xprt);
1106 static int svc_one_xprt_name(const struct svc_xprt *xprt,
1107 char *pos, int remaining)
1109 int len;
1111 len = snprintf(pos, remaining, "%s %u\n",
1112 xprt->xpt_class->xcl_name,
1113 svc_xprt_local_port(xprt));
1114 if (len >= remaining)
1115 return -ENAMETOOLONG;
1116 return len;
1120 * svc_xprt_names - format a buffer with a list of transport names
1121 * @serv: pointer to an RPC service
1122 * @buf: pointer to a buffer to be filled in
1123 * @buflen: length of buffer to be filled in
1125 * Fills in @buf with a string containing a list of transport names,
1126 * each name terminated with '\n'.
1128 * Returns positive length of the filled-in string on success; otherwise
1129 * a negative errno value is returned if an error occurs.
1131 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1133 struct svc_xprt *xprt;
1134 int len, totlen;
1135 char *pos;
1137 /* Sanity check args */
1138 if (!serv)
1139 return 0;
1141 spin_lock_bh(&serv->sv_lock);
1143 pos = buf;
1144 totlen = 0;
1145 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1146 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1147 if (len < 0) {
1148 *buf = '\0';
1149 totlen = len;
1151 if (len <= 0)
1152 break;
1154 pos += len;
1155 totlen += len;
1158 spin_unlock_bh(&serv->sv_lock);
1159 return totlen;
1161 EXPORT_SYMBOL_GPL(svc_xprt_names);
1164 /*----------------------------------------------------------------------------*/
1166 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1168 unsigned int pidx = (unsigned int)*pos;
1169 struct svc_serv *serv = m->private;
1171 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1173 if (!pidx)
1174 return SEQ_START_TOKEN;
1175 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1178 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1180 struct svc_pool *pool = p;
1181 struct svc_serv *serv = m->private;
1183 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1185 if (p == SEQ_START_TOKEN) {
1186 pool = &serv->sv_pools[0];
1187 } else {
1188 unsigned int pidx = (pool - &serv->sv_pools[0]);
1189 if (pidx < serv->sv_nrpools-1)
1190 pool = &serv->sv_pools[pidx+1];
1191 else
1192 pool = NULL;
1194 ++*pos;
1195 return pool;
1198 static void svc_pool_stats_stop(struct seq_file *m, void *p)
1202 static int svc_pool_stats_show(struct seq_file *m, void *p)
1204 struct svc_pool *pool = p;
1206 if (p == SEQ_START_TOKEN) {
1207 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken overloads-avoided threads-timedout\n");
1208 return 0;
1211 seq_printf(m, "%u %lu %lu %lu %lu %lu\n",
1212 pool->sp_id,
1213 pool->sp_stats.packets,
1214 pool->sp_stats.sockets_queued,
1215 pool->sp_stats.threads_woken,
1216 pool->sp_stats.overloads_avoided,
1217 pool->sp_stats.threads_timedout);
1219 return 0;
1222 static const struct seq_operations svc_pool_stats_seq_ops = {
1223 .start = svc_pool_stats_start,
1224 .next = svc_pool_stats_next,
1225 .stop = svc_pool_stats_stop,
1226 .show = svc_pool_stats_show,
1229 int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1231 int err;
1233 err = seq_open(file, &svc_pool_stats_seq_ops);
1234 if (!err)
1235 ((struct seq_file *) file->private_data)->private = serv;
1236 return err;
1238 EXPORT_SYMBOL(svc_pool_stats_open);
1240 /*----------------------------------------------------------------------------*/