2 * linux/net/sunrpc/svc_xprt.c
4 * Author: Tom Tucker <tom@opengridcomputing.com>
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 <linux/slab.h>
14 #include <linux/sunrpc/stats.h>
15 #include <linux/sunrpc/svc_xprt.h>
16 #include <linux/sunrpc/svcsock.h>
18 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
20 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
21 static int svc_deferred_recv(struct svc_rqst *rqstp);
22 static struct cache_deferred_req *svc_defer(struct cache_req *req);
23 static void svc_age_temp_xprts(unsigned long closure);
25 /* apparently the "standard" is that clients close
26 * idle connections after 5 minutes, servers after
28 * http://www.connectathon.org/talks96/nfstcp.pdf
30 static int svc_conn_age_period = 6*60;
32 /* List of registered transport classes */
33 static DEFINE_SPINLOCK(svc_xprt_class_lock);
34 static LIST_HEAD(svc_xprt_class_list);
36 /* SMP locking strategy:
38 * svc_pool->sp_lock protects most of the fields of that pool.
39 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
40 * when both need to be taken (rare), svc_serv->sv_lock is first.
41 * BKL protects svc_serv->sv_nrthread.
42 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
43 * and the ->sk_info_authunix cache.
45 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
46 * enqueued multiply. During normal transport processing this bit
47 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
48 * Providers should not manipulate this bit directly.
50 * Some flags can be set to certain values at any time
51 * providing that certain rules are followed:
54 * - Can be set or cleared at any time.
55 * - After a set, svc_xprt_enqueue must be called to enqueue
56 * the transport for processing.
57 * - After a clear, the transport must be read/accepted.
58 * If this succeeds, it must be set again.
60 * - Can set at any time. It is never cleared.
62 * - Can only be set while XPT_BUSY is held which ensures
63 * that no other thread will be using the transport or will
64 * try to set XPT_DEAD.
67 int svc_reg_xprt_class(struct svc_xprt_class *xcl)
69 struct svc_xprt_class *cl;
72 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
74 INIT_LIST_HEAD(&xcl->xcl_list);
75 spin_lock(&svc_xprt_class_lock);
76 /* Make sure there isn't already a class with the same name */
77 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
78 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
81 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
84 spin_unlock(&svc_xprt_class_lock);
87 EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
89 void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
91 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
92 spin_lock(&svc_xprt_class_lock);
93 list_del_init(&xcl->xcl_list);
94 spin_unlock(&svc_xprt_class_lock);
96 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
99 * Format the transport list for printing
101 int svc_print_xprts(char *buf, int maxlen)
103 struct svc_xprt_class *xcl;
108 spin_lock(&svc_xprt_class_lock);
109 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
112 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
113 slen = strlen(tmpstr);
114 if (len + slen > maxlen)
119 spin_unlock(&svc_xprt_class_lock);
124 static void svc_xprt_free(struct kref *kref)
126 struct svc_xprt *xprt =
127 container_of(kref, struct svc_xprt, xpt_ref);
128 struct module *owner = xprt->xpt_class->xcl_owner;
129 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
130 svcauth_unix_info_release(xprt);
131 put_net(xprt->xpt_net);
132 xprt->xpt_ops->xpo_free(xprt);
136 void svc_xprt_put(struct svc_xprt *xprt)
138 kref_put(&xprt->xpt_ref, svc_xprt_free);
140 EXPORT_SYMBOL_GPL(svc_xprt_put);
143 * Called by transport drivers to initialize the transport independent
144 * portion of the transport instance.
146 void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
147 struct svc_serv *serv)
149 memset(xprt, 0, sizeof(*xprt));
150 xprt->xpt_class = xcl;
151 xprt->xpt_ops = xcl->xcl_ops;
152 kref_init(&xprt->xpt_ref);
153 xprt->xpt_server = serv;
154 INIT_LIST_HEAD(&xprt->xpt_list);
155 INIT_LIST_HEAD(&xprt->xpt_ready);
156 INIT_LIST_HEAD(&xprt->xpt_deferred);
157 INIT_LIST_HEAD(&xprt->xpt_users);
158 mutex_init(&xprt->xpt_mutex);
159 spin_lock_init(&xprt->xpt_lock);
160 set_bit(XPT_BUSY, &xprt->xpt_flags);
161 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
162 xprt->xpt_net = get_net(&init_net);
164 EXPORT_SYMBOL_GPL(svc_xprt_init);
166 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
167 struct svc_serv *serv,
170 const unsigned short port,
173 struct sockaddr_in sin = {
174 .sin_family = AF_INET,
175 .sin_addr.s_addr = htonl(INADDR_ANY),
176 .sin_port = htons(port),
178 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
179 struct sockaddr_in6 sin6 = {
180 .sin6_family = AF_INET6,
181 .sin6_addr = IN6ADDR_ANY_INIT,
182 .sin6_port = htons(port),
184 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
185 struct sockaddr *sap;
190 sap = (struct sockaddr *)&sin;
193 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
195 sap = (struct sockaddr *)&sin6;
198 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
200 return ERR_PTR(-EAFNOSUPPORT);
203 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
206 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
207 struct net *net, const int family,
208 const unsigned short port, int flags)
210 struct svc_xprt_class *xcl;
212 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
213 spin_lock(&svc_xprt_class_lock);
214 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
215 struct svc_xprt *newxprt;
217 if (strcmp(xprt_name, xcl->xcl_name))
220 if (!try_module_get(xcl->xcl_owner))
223 spin_unlock(&svc_xprt_class_lock);
224 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
225 if (IS_ERR(newxprt)) {
226 module_put(xcl->xcl_owner);
227 return PTR_ERR(newxprt);
230 clear_bit(XPT_TEMP, &newxprt->xpt_flags);
231 spin_lock_bh(&serv->sv_lock);
232 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
233 spin_unlock_bh(&serv->sv_lock);
234 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
235 return svc_xprt_local_port(newxprt);
238 spin_unlock(&svc_xprt_class_lock);
239 dprintk("svc: transport %s not found\n", xprt_name);
241 /* This errno is exposed to user space. Provide a reasonable
242 * perror msg for a bad transport. */
243 return -EPROTONOSUPPORT;
245 EXPORT_SYMBOL_GPL(svc_create_xprt);
248 * Copy the local and remote xprt addresses to the rqstp structure
250 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
252 struct sockaddr *sin;
254 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
255 rqstp->rq_addrlen = xprt->xpt_remotelen;
258 * Destination address in request is needed for binding the
259 * source address in RPC replies/callbacks later.
261 sin = (struct sockaddr *)&xprt->xpt_local;
262 switch (sin->sa_family) {
264 rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
267 rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
271 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
274 * svc_print_addr - Format rq_addr field for printing
275 * @rqstp: svc_rqst struct containing address to print
276 * @buf: target buffer for formatted address
277 * @len: length of target buffer
280 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
282 return __svc_print_addr(svc_addr(rqstp), buf, len);
284 EXPORT_SYMBOL_GPL(svc_print_addr);
287 * Queue up an idle server thread. Must have pool->sp_lock held.
288 * Note: this is really a stack rather than a queue, so that we only
289 * use as many different threads as we need, and the rest don't pollute
292 static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
294 list_add(&rqstp->rq_list, &pool->sp_threads);
298 * Dequeue an nfsd thread. Must have pool->sp_lock held.
300 static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
302 list_del(&rqstp->rq_list);
306 * Queue up a transport with data pending. If there are idle nfsd
307 * processes, wake 'em up.
310 void svc_xprt_enqueue(struct svc_xprt *xprt)
312 struct svc_serv *serv = xprt->xpt_server;
313 struct svc_pool *pool;
314 struct svc_rqst *rqstp;
317 if (!(xprt->xpt_flags &
318 ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
322 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
325 spin_lock_bh(&pool->sp_lock);
327 if (!list_empty(&pool->sp_threads) &&
328 !list_empty(&pool->sp_sockets))
331 "threads and transports both waiting??\n");
333 pool->sp_stats.packets++;
335 /* Mark transport as busy. It will remain in this state until
336 * the provider calls svc_xprt_received. We update XPT_BUSY
337 * atomically because it also guards against trying to enqueue
338 * the transport twice.
340 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
341 /* Don't enqueue transport while already enqueued */
342 dprintk("svc: transport %p busy, not enqueued\n", xprt);
345 BUG_ON(xprt->xpt_pool != NULL);
346 xprt->xpt_pool = pool;
348 /* Handle pending connection */
349 if (test_bit(XPT_CONN, &xprt->xpt_flags))
352 /* Handle close in-progress */
353 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
356 /* Check if we have space to reply to a request */
357 if (!xprt->xpt_ops->xpo_has_wspace(xprt)) {
358 /* Don't enqueue while not enough space for reply */
359 dprintk("svc: no write space, transport %p not enqueued\n",
361 xprt->xpt_pool = NULL;
362 clear_bit(XPT_BUSY, &xprt->xpt_flags);
367 if (!list_empty(&pool->sp_threads)) {
368 rqstp = list_entry(pool->sp_threads.next,
371 dprintk("svc: transport %p served by daemon %p\n",
373 svc_thread_dequeue(pool, rqstp);
376 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
377 rqstp, rqstp->rq_xprt);
378 rqstp->rq_xprt = xprt;
380 rqstp->rq_reserved = serv->sv_max_mesg;
381 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
382 pool->sp_stats.threads_woken++;
383 BUG_ON(xprt->xpt_pool != pool);
384 wake_up(&rqstp->rq_wait);
386 dprintk("svc: transport %p put into queue\n", xprt);
387 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
388 pool->sp_stats.sockets_queued++;
389 BUG_ON(xprt->xpt_pool != pool);
393 spin_unlock_bh(&pool->sp_lock);
395 EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
398 * Dequeue the first transport. Must be called with the pool->sp_lock held.
400 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
402 struct svc_xprt *xprt;
404 if (list_empty(&pool->sp_sockets))
407 xprt = list_entry(pool->sp_sockets.next,
408 struct svc_xprt, xpt_ready);
409 list_del_init(&xprt->xpt_ready);
411 dprintk("svc: transport %p dequeued, inuse=%d\n",
412 xprt, atomic_read(&xprt->xpt_ref.refcount));
418 * svc_xprt_received conditionally queues the transport for processing
419 * by another thread. The caller must hold the XPT_BUSY bit and must
420 * not thereafter touch transport data.
422 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
423 * insufficient) data.
425 void svc_xprt_received(struct svc_xprt *xprt)
427 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
428 xprt->xpt_pool = NULL;
429 clear_bit(XPT_BUSY, &xprt->xpt_flags);
430 svc_xprt_enqueue(xprt);
432 EXPORT_SYMBOL_GPL(svc_xprt_received);
435 * svc_reserve - change the space reserved for the reply to a request.
436 * @rqstp: The request in question
437 * @space: new max space to reserve
439 * Each request reserves some space on the output queue of the transport
440 * to make sure the reply fits. This function reduces that reserved
441 * space to be the amount of space used already, plus @space.
444 void svc_reserve(struct svc_rqst *rqstp, int space)
446 space += rqstp->rq_res.head[0].iov_len;
448 if (space < rqstp->rq_reserved) {
449 struct svc_xprt *xprt = rqstp->rq_xprt;
450 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
451 rqstp->rq_reserved = space;
453 svc_xprt_enqueue(xprt);
456 EXPORT_SYMBOL_GPL(svc_reserve);
458 static void svc_xprt_release(struct svc_rqst *rqstp)
460 struct svc_xprt *xprt = rqstp->rq_xprt;
462 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
464 kfree(rqstp->rq_deferred);
465 rqstp->rq_deferred = NULL;
467 svc_free_res_pages(rqstp);
468 rqstp->rq_res.page_len = 0;
469 rqstp->rq_res.page_base = 0;
471 /* Reset response buffer and release
473 * But first, check that enough space was reserved
474 * for the reply, otherwise we have a bug!
476 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
477 printk(KERN_ERR "RPC request reserved %d but used %d\n",
481 rqstp->rq_res.head[0].iov_len = 0;
482 svc_reserve(rqstp, 0);
483 rqstp->rq_xprt = NULL;
489 * External function to wake up a server waiting for data
490 * This really only makes sense for services like lockd
491 * which have exactly one thread anyway.
493 void svc_wake_up(struct svc_serv *serv)
495 struct svc_rqst *rqstp;
497 struct svc_pool *pool;
499 for (i = 0; i < serv->sv_nrpools; i++) {
500 pool = &serv->sv_pools[i];
502 spin_lock_bh(&pool->sp_lock);
503 if (!list_empty(&pool->sp_threads)) {
504 rqstp = list_entry(pool->sp_threads.next,
507 dprintk("svc: daemon %p woken up.\n", rqstp);
509 svc_thread_dequeue(pool, rqstp);
510 rqstp->rq_xprt = NULL;
512 wake_up(&rqstp->rq_wait);
514 spin_unlock_bh(&pool->sp_lock);
517 EXPORT_SYMBOL_GPL(svc_wake_up);
519 int svc_port_is_privileged(struct sockaddr *sin)
521 switch (sin->sa_family) {
523 return ntohs(((struct sockaddr_in *)sin)->sin_port)
526 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
534 * Make sure that we don't have too many active connections. If we have,
535 * something must be dropped. It's not clear what will happen if we allow
536 * "too many" connections, but when dealing with network-facing software,
537 * we have to code defensively. Here we do that by imposing hard limits.
539 * There's no point in trying to do random drop here for DoS
540 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
541 * attacker can easily beat that.
543 * The only somewhat efficient mechanism would be if drop old
544 * connections from the same IP first. But right now we don't even
545 * record the client IP in svc_sock.
547 * single-threaded services that expect a lot of clients will probably
548 * need to set sv_maxconn to override the default value which is based
549 * on the number of threads
551 static void svc_check_conn_limits(struct svc_serv *serv)
553 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
554 (serv->sv_nrthreads+3) * 20;
556 if (serv->sv_tmpcnt > limit) {
557 struct svc_xprt *xprt = NULL;
558 spin_lock_bh(&serv->sv_lock);
559 if (!list_empty(&serv->sv_tempsocks)) {
560 if (net_ratelimit()) {
561 /* Try to help the admin */
562 printk(KERN_NOTICE "%s: too many open "
563 "connections, consider increasing %s\n",
564 serv->sv_name, serv->sv_maxconn ?
565 "the max number of connections." :
566 "the number of threads.");
569 * Always select the oldest connection. It's not fair,
572 xprt = list_entry(serv->sv_tempsocks.prev,
575 set_bit(XPT_CLOSE, &xprt->xpt_flags);
578 spin_unlock_bh(&serv->sv_lock);
581 svc_xprt_enqueue(xprt);
588 * Receive the next request on any transport. This code is carefully
589 * organised not to touch any cachelines in the shared svc_serv
590 * structure, only cachelines in the local svc_pool.
592 int svc_recv(struct svc_rqst *rqstp, long timeout)
594 struct svc_xprt *xprt = NULL;
595 struct svc_serv *serv = rqstp->rq_server;
596 struct svc_pool *pool = rqstp->rq_pool;
600 DECLARE_WAITQUEUE(wait, current);
603 dprintk("svc: server %p waiting for data (to = %ld)\n",
608 "svc_recv: service %p, transport not NULL!\n",
610 if (waitqueue_active(&rqstp->rq_wait))
612 "svc_recv: service %p, wait queue active!\n",
615 /* now allocate needed pages. If we get a failure, sleep briefly */
616 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
617 for (i = 0; i < pages ; i++)
618 while (rqstp->rq_pages[i] == NULL) {
619 struct page *p = alloc_page(GFP_KERNEL);
621 set_current_state(TASK_INTERRUPTIBLE);
622 if (signalled() || kthread_should_stop()) {
623 set_current_state(TASK_RUNNING);
626 schedule_timeout(msecs_to_jiffies(500));
628 rqstp->rq_pages[i] = p;
630 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
631 BUG_ON(pages >= RPCSVC_MAXPAGES);
633 /* Make arg->head point to first page and arg->pages point to rest */
634 arg = &rqstp->rq_arg;
635 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
636 arg->head[0].iov_len = PAGE_SIZE;
637 arg->pages = rqstp->rq_pages + 1;
639 /* save at least one page for response */
640 arg->page_len = (pages-2)*PAGE_SIZE;
641 arg->len = (pages-1)*PAGE_SIZE;
642 arg->tail[0].iov_len = 0;
646 if (signalled() || kthread_should_stop())
649 /* Normally we will wait up to 5 seconds for any required
650 * cache information to be provided.
652 rqstp->rq_chandle.thread_wait = 5*HZ;
654 spin_lock_bh(&pool->sp_lock);
655 xprt = svc_xprt_dequeue(pool);
657 rqstp->rq_xprt = xprt;
659 rqstp->rq_reserved = serv->sv_max_mesg;
660 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
662 /* As there is a shortage of threads and this request
663 * had to be queued, don't allow the thread to wait so
664 * long for cache updates.
666 rqstp->rq_chandle.thread_wait = 1*HZ;
668 /* No data pending. Go to sleep */
669 svc_thread_enqueue(pool, rqstp);
672 * We have to be able to interrupt this wait
673 * to bring down the daemons ...
675 set_current_state(TASK_INTERRUPTIBLE);
678 * checking kthread_should_stop() here allows us to avoid
679 * locking and signalling when stopping kthreads that call
680 * svc_recv. If the thread has already been woken up, then
681 * we can exit here without sleeping. If not, then it
682 * it'll be woken up quickly during the schedule_timeout
684 if (kthread_should_stop()) {
685 set_current_state(TASK_RUNNING);
686 spin_unlock_bh(&pool->sp_lock);
690 add_wait_queue(&rqstp->rq_wait, &wait);
691 spin_unlock_bh(&pool->sp_lock);
693 time_left = schedule_timeout(timeout);
697 spin_lock_bh(&pool->sp_lock);
698 remove_wait_queue(&rqstp->rq_wait, &wait);
700 pool->sp_stats.threads_timedout++;
702 xprt = rqstp->rq_xprt;
704 svc_thread_dequeue(pool, rqstp);
705 spin_unlock_bh(&pool->sp_lock);
706 dprintk("svc: server %p, no data yet\n", rqstp);
707 if (signalled() || kthread_should_stop())
713 spin_unlock_bh(&pool->sp_lock);
716 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
717 dprintk("svc_recv: found XPT_CLOSE\n");
718 svc_delete_xprt(xprt);
719 /* Leave XPT_BUSY set on the dead xprt: */
722 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
723 struct svc_xprt *newxpt;
724 newxpt = xprt->xpt_ops->xpo_accept(xprt);
727 * We know this module_get will succeed because the
728 * listener holds a reference too
730 __module_get(newxpt->xpt_class->xcl_owner);
731 svc_check_conn_limits(xprt->xpt_server);
732 spin_lock_bh(&serv->sv_lock);
733 set_bit(XPT_TEMP, &newxpt->xpt_flags);
734 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
736 if (serv->sv_temptimer.function == NULL) {
737 /* setup timer to age temp transports */
738 setup_timer(&serv->sv_temptimer,
740 (unsigned long)serv);
741 mod_timer(&serv->sv_temptimer,
742 jiffies + svc_conn_age_period * HZ);
744 spin_unlock_bh(&serv->sv_lock);
745 svc_xprt_received(newxpt);
748 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
749 rqstp, pool->sp_id, xprt,
750 atomic_read(&xprt->xpt_ref.refcount));
751 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
752 if (rqstp->rq_deferred)
753 len = svc_deferred_recv(rqstp);
755 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
756 dprintk("svc: got len=%d\n", len);
758 svc_xprt_received(xprt);
760 /* No data, incomplete (TCP) read, or accept() */
761 if (len == 0 || len == -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;
770 serv->sv_stats->netcnt++;
773 rqstp->rq_res.len = 0;
774 svc_xprt_release(rqstp);
777 EXPORT_SYMBOL_GPL(svc_recv);
782 void svc_drop(struct svc_rqst *rqstp)
784 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
785 svc_xprt_release(rqstp);
787 EXPORT_SYMBOL_GPL(svc_drop);
790 * Return reply to client.
792 int svc_send(struct svc_rqst *rqstp)
794 struct svc_xprt *xprt;
798 xprt = rqstp->rq_xprt;
802 /* release the receive skb before sending the reply */
803 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
805 /* calculate over-all length */
807 xb->len = xb->head[0].iov_len +
811 /* Grab mutex to serialize outgoing data. */
812 mutex_lock(&xprt->xpt_mutex);
813 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
816 len = xprt->xpt_ops->xpo_sendto(rqstp);
817 mutex_unlock(&xprt->xpt_mutex);
818 rpc_wake_up(&xprt->xpt_bc_pending);
819 svc_xprt_release(rqstp);
821 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
827 * Timer function to close old temporary transports, using
828 * a mark-and-sweep algorithm.
830 static void svc_age_temp_xprts(unsigned long closure)
832 struct svc_serv *serv = (struct svc_serv *)closure;
833 struct svc_xprt *xprt;
834 struct list_head *le, *next;
835 LIST_HEAD(to_be_aged);
837 dprintk("svc_age_temp_xprts\n");
839 if (!spin_trylock_bh(&serv->sv_lock)) {
840 /* busy, try again 1 sec later */
841 dprintk("svc_age_temp_xprts: busy\n");
842 mod_timer(&serv->sv_temptimer, jiffies + HZ);
846 list_for_each_safe(le, next, &serv->sv_tempsocks) {
847 xprt = list_entry(le, struct svc_xprt, xpt_list);
849 /* First time through, just mark it OLD. Second time
850 * through, close it. */
851 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
853 if (atomic_read(&xprt->xpt_ref.refcount) > 1 ||
854 test_bit(XPT_BUSY, &xprt->xpt_flags))
857 list_move(le, &to_be_aged);
858 set_bit(XPT_CLOSE, &xprt->xpt_flags);
859 set_bit(XPT_DETACHED, &xprt->xpt_flags);
861 spin_unlock_bh(&serv->sv_lock);
863 while (!list_empty(&to_be_aged)) {
864 le = to_be_aged.next;
865 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
867 xprt = list_entry(le, struct svc_xprt, xpt_list);
869 dprintk("queuing xprt %p for closing\n", xprt);
871 /* a thread will dequeue and close it soon */
872 svc_xprt_enqueue(xprt);
876 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
879 static void call_xpt_users(struct svc_xprt *xprt)
881 struct svc_xpt_user *u;
883 spin_lock(&xprt->xpt_lock);
884 while (!list_empty(&xprt->xpt_users)) {
885 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
889 spin_unlock(&xprt->xpt_lock);
893 * Remove a dead transport
895 void svc_delete_xprt(struct svc_xprt *xprt)
897 struct svc_serv *serv = xprt->xpt_server;
898 struct svc_deferred_req *dr;
900 /* Only do this once */
901 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
904 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
905 xprt->xpt_ops->xpo_detach(xprt);
907 spin_lock_bh(&serv->sv_lock);
908 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
909 list_del_init(&xprt->xpt_list);
911 * We used to delete the transport from whichever list
912 * it's sk_xprt.xpt_ready node was on, but we don't actually
913 * need to. This is because the only time we're called
914 * while still attached to a queue, the queue itself
915 * is about to be destroyed (in svc_destroy).
917 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
919 spin_unlock_bh(&serv->sv_lock);
921 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
924 call_xpt_users(xprt);
928 void svc_close_xprt(struct svc_xprt *xprt)
930 set_bit(XPT_CLOSE, &xprt->xpt_flags);
931 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
932 /* someone else will have to effect the close */
935 svc_delete_xprt(xprt);
937 EXPORT_SYMBOL_GPL(svc_close_xprt);
939 void svc_close_all(struct list_head *xprt_list)
941 struct svc_xprt *xprt;
942 struct svc_xprt *tmp;
944 list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
945 set_bit(XPT_CLOSE, &xprt->xpt_flags);
946 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) {
947 /* Waiting to be processed, but no threads left,
948 * So just remove it from the waiting list
950 list_del_init(&xprt->xpt_ready);
951 clear_bit(XPT_BUSY, &xprt->xpt_flags);
953 svc_close_xprt(xprt);
958 * Handle defer and revisit of requests
961 static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
963 struct svc_deferred_req *dr =
964 container_of(dreq, struct svc_deferred_req, handle);
965 struct svc_xprt *xprt = dr->xprt;
967 spin_lock(&xprt->xpt_lock);
968 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
969 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
970 spin_unlock(&xprt->xpt_lock);
971 dprintk("revisit canceled\n");
976 dprintk("revisit queued\n");
978 list_add(&dr->handle.recent, &xprt->xpt_deferred);
979 spin_unlock(&xprt->xpt_lock);
980 svc_xprt_enqueue(xprt);
985 * Save the request off for later processing. The request buffer looks
988 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
990 * This code can only handle requests that consist of an xprt-header
993 static struct cache_deferred_req *svc_defer(struct cache_req *req)
995 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
996 struct svc_deferred_req *dr;
998 if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral)
999 return NULL; /* if more than a page, give up FIXME */
1000 if (rqstp->rq_deferred) {
1001 dr = rqstp->rq_deferred;
1002 rqstp->rq_deferred = NULL;
1006 /* FIXME maybe discard if size too large */
1007 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
1008 dr = kmalloc(size, GFP_KERNEL);
1012 dr->handle.owner = rqstp->rq_server;
1013 dr->prot = rqstp->rq_prot;
1014 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1015 dr->addrlen = rqstp->rq_addrlen;
1016 dr->daddr = rqstp->rq_daddr;
1017 dr->argslen = rqstp->rq_arg.len >> 2;
1018 dr->xprt_hlen = rqstp->rq_xprt_hlen;
1020 /* back up head to the start of the buffer and copy */
1021 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1022 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1025 svc_xprt_get(rqstp->rq_xprt);
1026 dr->xprt = rqstp->rq_xprt;
1028 dr->handle.revisit = svc_revisit;
1033 * recv data from a deferred request into an active one
1035 static int svc_deferred_recv(struct svc_rqst *rqstp)
1037 struct svc_deferred_req *dr = rqstp->rq_deferred;
1039 /* setup iov_base past transport header */
1040 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1041 /* The iov_len does not include the transport header bytes */
1042 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
1043 rqstp->rq_arg.page_len = 0;
1044 /* The rq_arg.len includes the transport header bytes */
1045 rqstp->rq_arg.len = dr->argslen<<2;
1046 rqstp->rq_prot = dr->prot;
1047 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1048 rqstp->rq_addrlen = dr->addrlen;
1049 /* Save off transport header len in case we get deferred again */
1050 rqstp->rq_xprt_hlen = dr->xprt_hlen;
1051 rqstp->rq_daddr = dr->daddr;
1052 rqstp->rq_respages = rqstp->rq_pages;
1053 return (dr->argslen<<2) - dr->xprt_hlen;
1057 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1059 struct svc_deferred_req *dr = NULL;
1061 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1063 spin_lock(&xprt->xpt_lock);
1064 if (!list_empty(&xprt->xpt_deferred)) {
1065 dr = list_entry(xprt->xpt_deferred.next,
1066 struct svc_deferred_req,
1068 list_del_init(&dr->handle.recent);
1070 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1071 spin_unlock(&xprt->xpt_lock);
1076 * svc_find_xprt - find an RPC transport instance
1077 * @serv: pointer to svc_serv to search
1078 * @xcl_name: C string containing transport's class name
1079 * @af: Address family of transport's local address
1080 * @port: transport's IP port number
1082 * Return the transport instance pointer for the endpoint accepting
1083 * connections/peer traffic from the specified transport class,
1084 * address family and port.
1086 * Specifying 0 for the address family or port is effectively a
1087 * wild-card, and will result in matching the first transport in the
1088 * service's list that has a matching class name.
1090 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1091 const sa_family_t af, const unsigned short port)
1093 struct svc_xprt *xprt;
1094 struct svc_xprt *found = NULL;
1096 /* Sanity check the args */
1097 if (serv == NULL || xcl_name == NULL)
1100 spin_lock_bh(&serv->sv_lock);
1101 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1102 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1104 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1106 if (port != 0 && port != svc_xprt_local_port(xprt))
1112 spin_unlock_bh(&serv->sv_lock);
1115 EXPORT_SYMBOL_GPL(svc_find_xprt);
1117 static int svc_one_xprt_name(const struct svc_xprt *xprt,
1118 char *pos, int remaining)
1122 len = snprintf(pos, remaining, "%s %u\n",
1123 xprt->xpt_class->xcl_name,
1124 svc_xprt_local_port(xprt));
1125 if (len >= remaining)
1126 return -ENAMETOOLONG;
1131 * svc_xprt_names - format a buffer with a list of transport names
1132 * @serv: pointer to an RPC service
1133 * @buf: pointer to a buffer to be filled in
1134 * @buflen: length of buffer to be filled in
1136 * Fills in @buf with a string containing a list of transport names,
1137 * each name terminated with '\n'.
1139 * Returns positive length of the filled-in string on success; otherwise
1140 * a negative errno value is returned if an error occurs.
1142 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1144 struct svc_xprt *xprt;
1148 /* Sanity check args */
1152 spin_lock_bh(&serv->sv_lock);
1156 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1157 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1169 spin_unlock_bh(&serv->sv_lock);
1172 EXPORT_SYMBOL_GPL(svc_xprt_names);
1175 /*----------------------------------------------------------------------------*/
1177 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1179 unsigned int pidx = (unsigned int)*pos;
1180 struct svc_serv *serv = m->private;
1182 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1185 return SEQ_START_TOKEN;
1186 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1189 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1191 struct svc_pool *pool = p;
1192 struct svc_serv *serv = m->private;
1194 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1196 if (p == SEQ_START_TOKEN) {
1197 pool = &serv->sv_pools[0];
1199 unsigned int pidx = (pool - &serv->sv_pools[0]);
1200 if (pidx < serv->sv_nrpools-1)
1201 pool = &serv->sv_pools[pidx+1];
1209 static void svc_pool_stats_stop(struct seq_file *m, void *p)
1213 static int svc_pool_stats_show(struct seq_file *m, void *p)
1215 struct svc_pool *pool = p;
1217 if (p == SEQ_START_TOKEN) {
1218 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1222 seq_printf(m, "%u %lu %lu %lu %lu\n",
1224 pool->sp_stats.packets,
1225 pool->sp_stats.sockets_queued,
1226 pool->sp_stats.threads_woken,
1227 pool->sp_stats.threads_timedout);
1232 static const struct seq_operations svc_pool_stats_seq_ops = {
1233 .start = svc_pool_stats_start,
1234 .next = svc_pool_stats_next,
1235 .stop = svc_pool_stats_stop,
1236 .show = svc_pool_stats_show,
1239 int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1243 err = seq_open(file, &svc_pool_stats_seq_ops);
1245 ((struct seq_file *) file->private_data)->private = serv;
1248 EXPORT_SYMBOL(svc_pool_stats_open);
1250 /*----------------------------------------------------------------------------*/