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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/svc_xprt.c
4 *
5 * Author: Tom Tucker <tom@opengridcomputing.com>
6 */
7
8#include <linux/sched.h>
9#include <linux/errno.h>
10#include <linux/freezer.h>
11#include <linux/kthread.h>
12#include <linux/slab.h>
13#include <net/sock.h>
14#include <linux/sunrpc/addr.h>
15#include <linux/sunrpc/stats.h>
16#include <linux/sunrpc/svc_xprt.h>
17#include <linux/sunrpc/svcsock.h>
18#include <linux/sunrpc/xprt.h>
19#include <linux/module.h>
20#include <linux/netdevice.h>
21#include <trace/events/sunrpc.h>
22
23#define RPCDBG_FACILITY RPCDBG_SVCXPRT
24
25static unsigned int svc_rpc_per_connection_limit __read_mostly;
26module_param(svc_rpc_per_connection_limit, uint, 0644);
27
28
29static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
30static int svc_deferred_recv(struct svc_rqst *rqstp);
31static struct cache_deferred_req *svc_defer(struct cache_req *req);
32static void svc_age_temp_xprts(struct timer_list *t);
33static void svc_delete_xprt(struct svc_xprt *xprt);
34
35/* apparently the "standard" is that clients close
36 * idle connections after 5 minutes, servers after
37 * 6 minutes
38 * http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf
39 */
40static int svc_conn_age_period = 6*60;
41
42/* List of registered transport classes */
43static DEFINE_SPINLOCK(svc_xprt_class_lock);
44static LIST_HEAD(svc_xprt_class_list);
45
46/* SMP locking strategy:
47 *
48 * svc_pool->sp_lock protects most of the fields of that pool.
49 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
50 * when both need to be taken (rare), svc_serv->sv_lock is first.
51 * The "service mutex" protects svc_serv->sv_nrthread.
52 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
53 * and the ->sk_info_authunix cache.
54 *
55 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
56 * enqueued multiply. During normal transport processing this bit
57 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
58 * Providers should not manipulate this bit directly.
59 *
60 * Some flags can be set to certain values at any time
61 * providing that certain rules are followed:
62 *
63 * XPT_CONN, XPT_DATA:
64 * - Can be set or cleared at any time.
65 * - After a set, svc_xprt_enqueue must be called to enqueue
66 * the transport for processing.
67 * - After a clear, the transport must be read/accepted.
68 * If this succeeds, it must be set again.
69 * XPT_CLOSE:
70 * - Can set at any time. It is never cleared.
71 * XPT_DEAD:
72 * - Can only be set while XPT_BUSY is held which ensures
73 * that no other thread will be using the transport or will
74 * try to set XPT_DEAD.
75 */
76int svc_reg_xprt_class(struct svc_xprt_class *xcl)
77{
78 struct svc_xprt_class *cl;
79 int res = -EEXIST;
80
81 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
82
83 INIT_LIST_HEAD(&xcl->xcl_list);
84 spin_lock(&svc_xprt_class_lock);
85 /* Make sure there isn't already a class with the same name */
86 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
87 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
88 goto out;
89 }
90 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
91 res = 0;
92out:
93 spin_unlock(&svc_xprt_class_lock);
94 return res;
95}
96EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
97
98void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
99{
100 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
101 spin_lock(&svc_xprt_class_lock);
102 list_del_init(&xcl->xcl_list);
103 spin_unlock(&svc_xprt_class_lock);
104}
105EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
106
107/*
108 * Format the transport list for printing
109 */
110int svc_print_xprts(char *buf, int maxlen)
111{
112 struct svc_xprt_class *xcl;
113 char tmpstr[80];
114 int len = 0;
115 buf[0] = '\0';
116
117 spin_lock(&svc_xprt_class_lock);
118 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
119 int slen;
120
121 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
122 slen = strlen(tmpstr);
123 if (len + slen > maxlen)
124 break;
125 len += slen;
126 strcat(buf, tmpstr);
127 }
128 spin_unlock(&svc_xprt_class_lock);
129
130 return len;
131}
132
133static void svc_xprt_free(struct kref *kref)
134{
135 struct svc_xprt *xprt =
136 container_of(kref, struct svc_xprt, xpt_ref);
137 struct module *owner = xprt->xpt_class->xcl_owner;
138 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
139 svcauth_unix_info_release(xprt);
140 put_cred(xprt->xpt_cred);
141 put_net(xprt->xpt_net);
142 /* See comment on corresponding get in xs_setup_bc_tcp(): */
143 if (xprt->xpt_bc_xprt)
144 xprt_put(xprt->xpt_bc_xprt);
145 if (xprt->xpt_bc_xps)
146 xprt_switch_put(xprt->xpt_bc_xps);
147 xprt->xpt_ops->xpo_free(xprt);
148 module_put(owner);
149}
150
151void svc_xprt_put(struct svc_xprt *xprt)
152{
153 kref_put(&xprt->xpt_ref, svc_xprt_free);
154}
155EXPORT_SYMBOL_GPL(svc_xprt_put);
156
157/*
158 * Called by transport drivers to initialize the transport independent
159 * portion of the transport instance.
160 */
161void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
162 struct svc_xprt *xprt, struct svc_serv *serv)
163{
164 memset(xprt, 0, sizeof(*xprt));
165 xprt->xpt_class = xcl;
166 xprt->xpt_ops = xcl->xcl_ops;
167 kref_init(&xprt->xpt_ref);
168 xprt->xpt_server = serv;
169 INIT_LIST_HEAD(&xprt->xpt_list);
170 INIT_LIST_HEAD(&xprt->xpt_ready);
171 INIT_LIST_HEAD(&xprt->xpt_deferred);
172 INIT_LIST_HEAD(&xprt->xpt_users);
173 mutex_init(&xprt->xpt_mutex);
174 spin_lock_init(&xprt->xpt_lock);
175 set_bit(XPT_BUSY, &xprt->xpt_flags);
176 xprt->xpt_net = get_net(net);
177 strcpy(xprt->xpt_remotebuf, "uninitialized");
178}
179EXPORT_SYMBOL_GPL(svc_xprt_init);
180
181static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
182 struct svc_serv *serv,
183 struct net *net,
184 const int family,
185 const unsigned short port,
186 int flags)
187{
188 struct sockaddr_in sin = {
189 .sin_family = AF_INET,
190 .sin_addr.s_addr = htonl(INADDR_ANY),
191 .sin_port = htons(port),
192 };
193#if IS_ENABLED(CONFIG_IPV6)
194 struct sockaddr_in6 sin6 = {
195 .sin6_family = AF_INET6,
196 .sin6_addr = IN6ADDR_ANY_INIT,
197 .sin6_port = htons(port),
198 };
199#endif
200 struct sockaddr *sap;
201 size_t len;
202
203 switch (family) {
204 case PF_INET:
205 sap = (struct sockaddr *)&sin;
206 len = sizeof(sin);
207 break;
208#if IS_ENABLED(CONFIG_IPV6)
209 case PF_INET6:
210 sap = (struct sockaddr *)&sin6;
211 len = sizeof(sin6);
212 break;
213#endif
214 default:
215 return ERR_PTR(-EAFNOSUPPORT);
216 }
217
218 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
219}
220
221/*
222 * svc_xprt_received conditionally queues the transport for processing
223 * by another thread. The caller must hold the XPT_BUSY bit and must
224 * not thereafter touch transport data.
225 *
226 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
227 * insufficient) data.
228 */
229static void svc_xprt_received(struct svc_xprt *xprt)
230{
231 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) {
232 WARN_ONCE(1, "xprt=0x%p already busy!", xprt);
233 return;
234 }
235
236 /* As soon as we clear busy, the xprt could be closed and
237 * 'put', so we need a reference to call svc_enqueue_xprt with:
238 */
239 svc_xprt_get(xprt);
240 smp_mb__before_atomic();
241 clear_bit(XPT_BUSY, &xprt->xpt_flags);
242 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt);
243 svc_xprt_put(xprt);
244}
245
246void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new)
247{
248 clear_bit(XPT_TEMP, &new->xpt_flags);
249 spin_lock_bh(&serv->sv_lock);
250 list_add(&new->xpt_list, &serv->sv_permsocks);
251 spin_unlock_bh(&serv->sv_lock);
252 svc_xprt_received(new);
253}
254
255static int _svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
256 struct net *net, const int family,
257 const unsigned short port, int flags,
258 const struct cred *cred)
259{
260 struct svc_xprt_class *xcl;
261
262 spin_lock(&svc_xprt_class_lock);
263 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
264 struct svc_xprt *newxprt;
265 unsigned short newport;
266
267 if (strcmp(xprt_name, xcl->xcl_name))
268 continue;
269
270 if (!try_module_get(xcl->xcl_owner))
271 goto err;
272
273 spin_unlock(&svc_xprt_class_lock);
274 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
275 if (IS_ERR(newxprt)) {
276 module_put(xcl->xcl_owner);
277 return PTR_ERR(newxprt);
278 }
279 newxprt->xpt_cred = get_cred(cred);
280 svc_add_new_perm_xprt(serv, newxprt);
281 newport = svc_xprt_local_port(newxprt);
282 return newport;
283 }
284 err:
285 spin_unlock(&svc_xprt_class_lock);
286 /* This errno is exposed to user space. Provide a reasonable
287 * perror msg for a bad transport. */
288 return -EPROTONOSUPPORT;
289}
290
291int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
292 struct net *net, const int family,
293 const unsigned short port, int flags,
294 const struct cred *cred)
295{
296 int err;
297
298 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
299 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred);
300 if (err == -EPROTONOSUPPORT) {
301 request_module("svc%s", xprt_name);
302 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred);
303 }
304 if (err < 0)
305 dprintk("svc: transport %s not found, err %d\n",
306 xprt_name, -err);
307 return err;
308}
309EXPORT_SYMBOL_GPL(svc_create_xprt);
310
311/*
312 * Copy the local and remote xprt addresses to the rqstp structure
313 */
314void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
315{
316 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
317 rqstp->rq_addrlen = xprt->xpt_remotelen;
318
319 /*
320 * Destination address in request is needed for binding the
321 * source address in RPC replies/callbacks later.
322 */
323 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen);
324 rqstp->rq_daddrlen = xprt->xpt_locallen;
325}
326EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
327
328/**
329 * svc_print_addr - Format rq_addr field for printing
330 * @rqstp: svc_rqst struct containing address to print
331 * @buf: target buffer for formatted address
332 * @len: length of target buffer
333 *
334 */
335char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
336{
337 return __svc_print_addr(svc_addr(rqstp), buf, len);
338}
339EXPORT_SYMBOL_GPL(svc_print_addr);
340
341static bool svc_xprt_slots_in_range(struct svc_xprt *xprt)
342{
343 unsigned int limit = svc_rpc_per_connection_limit;
344 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts);
345
346 return limit == 0 || (nrqsts >= 0 && nrqsts < limit);
347}
348
349static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt)
350{
351 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) {
352 if (!svc_xprt_slots_in_range(xprt))
353 return false;
354 atomic_inc(&xprt->xpt_nr_rqsts);
355 set_bit(RQ_DATA, &rqstp->rq_flags);
356 }
357 return true;
358}
359
360static void svc_xprt_release_slot(struct svc_rqst *rqstp)
361{
362 struct svc_xprt *xprt = rqstp->rq_xprt;
363 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) {
364 atomic_dec(&xprt->xpt_nr_rqsts);
365 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
366 svc_xprt_enqueue(xprt);
367 }
368}
369
370static bool svc_xprt_ready(struct svc_xprt *xprt)
371{
372 unsigned long xpt_flags;
373
374 /*
375 * If another cpu has recently updated xpt_flags,
376 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to
377 * know about it; otherwise it's possible that both that cpu and
378 * this one could call svc_xprt_enqueue() without either
379 * svc_xprt_enqueue() recognizing that the conditions below
380 * are satisfied, and we could stall indefinitely:
381 */
382 smp_rmb();
383 xpt_flags = READ_ONCE(xprt->xpt_flags);
384
385 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE)))
386 return true;
387 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) {
388 if (xprt->xpt_ops->xpo_has_wspace(xprt) &&
389 svc_xprt_slots_in_range(xprt))
390 return true;
391 trace_svc_xprt_no_write_space(xprt);
392 return false;
393 }
394 return false;
395}
396
397void svc_xprt_do_enqueue(struct svc_xprt *xprt)
398{
399 struct svc_pool *pool;
400 struct svc_rqst *rqstp = NULL;
401 int cpu;
402
403 if (!svc_xprt_ready(xprt))
404 return;
405
406 /* Mark transport as busy. It will remain in this state until
407 * the provider calls svc_xprt_received. We update XPT_BUSY
408 * atomically because it also guards against trying to enqueue
409 * the transport twice.
410 */
411 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
412 return;
413
414 cpu = get_cpu();
415 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
416
417 atomic_long_inc(&pool->sp_stats.packets);
418
419 spin_lock_bh(&pool->sp_lock);
420 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
421 pool->sp_stats.sockets_queued++;
422 spin_unlock_bh(&pool->sp_lock);
423
424 /* find a thread for this xprt */
425 rcu_read_lock();
426 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
427 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags))
428 continue;
429 atomic_long_inc(&pool->sp_stats.threads_woken);
430 rqstp->rq_qtime = ktime_get();
431 wake_up_process(rqstp->rq_task);
432 goto out_unlock;
433 }
434 set_bit(SP_CONGESTED, &pool->sp_flags);
435 rqstp = NULL;
436out_unlock:
437 rcu_read_unlock();
438 put_cpu();
439 trace_svc_xprt_do_enqueue(xprt, rqstp);
440}
441EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue);
442
443/*
444 * Queue up a transport with data pending. If there are idle nfsd
445 * processes, wake 'em up.
446 *
447 */
448void svc_xprt_enqueue(struct svc_xprt *xprt)
449{
450 if (test_bit(XPT_BUSY, &xprt->xpt_flags))
451 return;
452 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt);
453}
454EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
455
456/*
457 * Dequeue the first transport, if there is one.
458 */
459static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
460{
461 struct svc_xprt *xprt = NULL;
462
463 if (list_empty(&pool->sp_sockets))
464 goto out;
465
466 spin_lock_bh(&pool->sp_lock);
467 if (likely(!list_empty(&pool->sp_sockets))) {
468 xprt = list_first_entry(&pool->sp_sockets,
469 struct svc_xprt, xpt_ready);
470 list_del_init(&xprt->xpt_ready);
471 svc_xprt_get(xprt);
472 }
473 spin_unlock_bh(&pool->sp_lock);
474out:
475 return xprt;
476}
477
478/**
479 * svc_reserve - change the space reserved for the reply to a request.
480 * @rqstp: The request in question
481 * @space: new max space to reserve
482 *
483 * Each request reserves some space on the output queue of the transport
484 * to make sure the reply fits. This function reduces that reserved
485 * space to be the amount of space used already, plus @space.
486 *
487 */
488void svc_reserve(struct svc_rqst *rqstp, int space)
489{
490 struct svc_xprt *xprt = rqstp->rq_xprt;
491
492 space += rqstp->rq_res.head[0].iov_len;
493
494 if (xprt && space < rqstp->rq_reserved) {
495 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
496 rqstp->rq_reserved = space;
497 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
498 svc_xprt_enqueue(xprt);
499 }
500}
501EXPORT_SYMBOL_GPL(svc_reserve);
502
503static void svc_xprt_release(struct svc_rqst *rqstp)
504{
505 struct svc_xprt *xprt = rqstp->rq_xprt;
506
507 xprt->xpt_ops->xpo_release_rqst(rqstp);
508
509 kfree(rqstp->rq_deferred);
510 rqstp->rq_deferred = NULL;
511
512 svc_free_res_pages(rqstp);
513 rqstp->rq_res.page_len = 0;
514 rqstp->rq_res.page_base = 0;
515
516 /* Reset response buffer and release
517 * the reservation.
518 * But first, check that enough space was reserved
519 * for the reply, otherwise we have a bug!
520 */
521 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
522 printk(KERN_ERR "RPC request reserved %d but used %d\n",
523 rqstp->rq_reserved,
524 rqstp->rq_res.len);
525
526 rqstp->rq_res.head[0].iov_len = 0;
527 svc_reserve(rqstp, 0);
528 svc_xprt_release_slot(rqstp);
529 rqstp->rq_xprt = NULL;
530 svc_xprt_put(xprt);
531}
532
533/*
534 * Some svc_serv's will have occasional work to do, even when a xprt is not
535 * waiting to be serviced. This function is there to "kick" a task in one of
536 * those services so that it can wake up and do that work. Note that we only
537 * bother with pool 0 as we don't need to wake up more than one thread for
538 * this purpose.
539 */
540void svc_wake_up(struct svc_serv *serv)
541{
542 struct svc_rqst *rqstp;
543 struct svc_pool *pool;
544
545 pool = &serv->sv_pools[0];
546
547 rcu_read_lock();
548 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
549 /* skip any that aren't queued */
550 if (test_bit(RQ_BUSY, &rqstp->rq_flags))
551 continue;
552 rcu_read_unlock();
553 wake_up_process(rqstp->rq_task);
554 trace_svc_wake_up(rqstp->rq_task->pid);
555 return;
556 }
557 rcu_read_unlock();
558
559 /* No free entries available */
560 set_bit(SP_TASK_PENDING, &pool->sp_flags);
561 smp_wmb();
562 trace_svc_wake_up(0);
563}
564EXPORT_SYMBOL_GPL(svc_wake_up);
565
566int svc_port_is_privileged(struct sockaddr *sin)
567{
568 switch (sin->sa_family) {
569 case AF_INET:
570 return ntohs(((struct sockaddr_in *)sin)->sin_port)
571 < PROT_SOCK;
572 case AF_INET6:
573 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
574 < PROT_SOCK;
575 default:
576 return 0;
577 }
578}
579
580/*
581 * Make sure that we don't have too many active connections. If we have,
582 * something must be dropped. It's not clear what will happen if we allow
583 * "too many" connections, but when dealing with network-facing software,
584 * we have to code defensively. Here we do that by imposing hard limits.
585 *
586 * There's no point in trying to do random drop here for DoS
587 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
588 * attacker can easily beat that.
589 *
590 * The only somewhat efficient mechanism would be if drop old
591 * connections from the same IP first. But right now we don't even
592 * record the client IP in svc_sock.
593 *
594 * single-threaded services that expect a lot of clients will probably
595 * need to set sv_maxconn to override the default value which is based
596 * on the number of threads
597 */
598static void svc_check_conn_limits(struct svc_serv *serv)
599{
600 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
601 (serv->sv_nrthreads+3) * 20;
602
603 if (serv->sv_tmpcnt > limit) {
604 struct svc_xprt *xprt = NULL;
605 spin_lock_bh(&serv->sv_lock);
606 if (!list_empty(&serv->sv_tempsocks)) {
607 /* Try to help the admin */
608 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
609 serv->sv_name, serv->sv_maxconn ?
610 "max number of connections" :
611 "number of threads");
612 /*
613 * Always select the oldest connection. It's not fair,
614 * but so is life
615 */
616 xprt = list_entry(serv->sv_tempsocks.prev,
617 struct svc_xprt,
618 xpt_list);
619 set_bit(XPT_CLOSE, &xprt->xpt_flags);
620 svc_xprt_get(xprt);
621 }
622 spin_unlock_bh(&serv->sv_lock);
623
624 if (xprt) {
625 svc_xprt_enqueue(xprt);
626 svc_xprt_put(xprt);
627 }
628 }
629}
630
631static int svc_alloc_arg(struct svc_rqst *rqstp)
632{
633 struct svc_serv *serv = rqstp->rq_server;
634 struct xdr_buf *arg;
635 int pages;
636 int i;
637
638 /* now allocate needed pages. If we get a failure, sleep briefly */
639 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT;
640 if (pages > RPCSVC_MAXPAGES) {
641 pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n",
642 pages, RPCSVC_MAXPAGES);
643 /* use as many pages as possible */
644 pages = RPCSVC_MAXPAGES;
645 }
646 for (i = 0; i < pages ; i++)
647 while (rqstp->rq_pages[i] == NULL) {
648 struct page *p = alloc_page(GFP_KERNEL);
649 if (!p) {
650 set_current_state(TASK_INTERRUPTIBLE);
651 if (signalled() || kthread_should_stop()) {
652 set_current_state(TASK_RUNNING);
653 return -EINTR;
654 }
655 schedule_timeout(msecs_to_jiffies(500));
656 }
657 rqstp->rq_pages[i] = p;
658 }
659 rqstp->rq_page_end = &rqstp->rq_pages[i];
660 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
661
662 /* Make arg->head point to first page and arg->pages point to rest */
663 arg = &rqstp->rq_arg;
664 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
665 arg->head[0].iov_len = PAGE_SIZE;
666 arg->pages = rqstp->rq_pages + 1;
667 arg->page_base = 0;
668 /* save at least one page for response */
669 arg->page_len = (pages-2)*PAGE_SIZE;
670 arg->len = (pages-1)*PAGE_SIZE;
671 arg->tail[0].iov_len = 0;
672 return 0;
673}
674
675static bool
676rqst_should_sleep(struct svc_rqst *rqstp)
677{
678 struct svc_pool *pool = rqstp->rq_pool;
679
680 /* did someone call svc_wake_up? */
681 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags))
682 return false;
683
684 /* was a socket queued? */
685 if (!list_empty(&pool->sp_sockets))
686 return false;
687
688 /* are we shutting down? */
689 if (signalled() || kthread_should_stop())
690 return false;
691
692 /* are we freezing? */
693 if (freezing(current))
694 return false;
695
696 return true;
697}
698
699static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
700{
701 struct svc_pool *pool = rqstp->rq_pool;
702 long time_left = 0;
703
704 /* rq_xprt should be clear on entry */
705 WARN_ON_ONCE(rqstp->rq_xprt);
706
707 rqstp->rq_xprt = svc_xprt_dequeue(pool);
708 if (rqstp->rq_xprt)
709 goto out_found;
710
711 /*
712 * We have to be able to interrupt this wait
713 * to bring down the daemons ...
714 */
715 set_current_state(TASK_INTERRUPTIBLE);
716 smp_mb__before_atomic();
717 clear_bit(SP_CONGESTED, &pool->sp_flags);
718 clear_bit(RQ_BUSY, &rqstp->rq_flags);
719 smp_mb__after_atomic();
720
721 if (likely(rqst_should_sleep(rqstp)))
722 time_left = schedule_timeout(timeout);
723 else
724 __set_current_state(TASK_RUNNING);
725
726 try_to_freeze();
727
728 set_bit(RQ_BUSY, &rqstp->rq_flags);
729 smp_mb__after_atomic();
730 rqstp->rq_xprt = svc_xprt_dequeue(pool);
731 if (rqstp->rq_xprt)
732 goto out_found;
733
734 if (!time_left)
735 atomic_long_inc(&pool->sp_stats.threads_timedout);
736
737 if (signalled() || kthread_should_stop())
738 return ERR_PTR(-EINTR);
739 return ERR_PTR(-EAGAIN);
740out_found:
741 /* Normally we will wait up to 5 seconds for any required
742 * cache information to be provided.
743 */
744 if (!test_bit(SP_CONGESTED, &pool->sp_flags))
745 rqstp->rq_chandle.thread_wait = 5*HZ;
746 else
747 rqstp->rq_chandle.thread_wait = 1*HZ;
748 trace_svc_xprt_dequeue(rqstp);
749 return rqstp->rq_xprt;
750}
751
752static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt)
753{
754 spin_lock_bh(&serv->sv_lock);
755 set_bit(XPT_TEMP, &newxpt->xpt_flags);
756 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
757 serv->sv_tmpcnt++;
758 if (serv->sv_temptimer.function == NULL) {
759 /* setup timer to age temp transports */
760 serv->sv_temptimer.function = svc_age_temp_xprts;
761 mod_timer(&serv->sv_temptimer,
762 jiffies + svc_conn_age_period * HZ);
763 }
764 spin_unlock_bh(&serv->sv_lock);
765 svc_xprt_received(newxpt);
766}
767
768static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
769{
770 struct svc_serv *serv = rqstp->rq_server;
771 int len = 0;
772
773 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
774 dprintk("svc_recv: found XPT_CLOSE\n");
775 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags))
776 xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
777 svc_delete_xprt(xprt);
778 /* Leave XPT_BUSY set on the dead xprt: */
779 goto out;
780 }
781 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
782 struct svc_xprt *newxpt;
783 /*
784 * We know this module_get will succeed because the
785 * listener holds a reference too
786 */
787 __module_get(xprt->xpt_class->xcl_owner);
788 svc_check_conn_limits(xprt->xpt_server);
789 newxpt = xprt->xpt_ops->xpo_accept(xprt);
790 if (newxpt) {
791 newxpt->xpt_cred = get_cred(xprt->xpt_cred);
792 svc_add_new_temp_xprt(serv, newxpt);
793 } else
794 module_put(xprt->xpt_class->xcl_owner);
795 } else if (svc_xprt_reserve_slot(rqstp, xprt)) {
796 /* XPT_DATA|XPT_DEFERRED case: */
797 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
798 rqstp, rqstp->rq_pool->sp_id, xprt,
799 kref_read(&xprt->xpt_ref));
800 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
801 if (rqstp->rq_deferred)
802 len = svc_deferred_recv(rqstp);
803 else
804 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
805 rqstp->rq_stime = ktime_get();
806 rqstp->rq_reserved = serv->sv_max_mesg;
807 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
808 }
809 /* clear XPT_BUSY: */
810 svc_xprt_received(xprt);
811out:
812 trace_svc_handle_xprt(xprt, len);
813 return len;
814}
815
816/*
817 * Receive the next request on any transport. This code is carefully
818 * organised not to touch any cachelines in the shared svc_serv
819 * structure, only cachelines in the local svc_pool.
820 */
821int svc_recv(struct svc_rqst *rqstp, long timeout)
822{
823 struct svc_xprt *xprt = NULL;
824 struct svc_serv *serv = rqstp->rq_server;
825 int len, err;
826
827 dprintk("svc: server %p waiting for data (to = %ld)\n",
828 rqstp, timeout);
829
830 if (rqstp->rq_xprt)
831 printk(KERN_ERR
832 "svc_recv: service %p, transport not NULL!\n",
833 rqstp);
834
835 err = svc_alloc_arg(rqstp);
836 if (err)
837 goto out;
838
839 try_to_freeze();
840 cond_resched();
841 err = -EINTR;
842 if (signalled() || kthread_should_stop())
843 goto out;
844
845 xprt = svc_get_next_xprt(rqstp, timeout);
846 if (IS_ERR(xprt)) {
847 err = PTR_ERR(xprt);
848 goto out;
849 }
850
851 len = svc_handle_xprt(rqstp, xprt);
852
853 /* No data, incomplete (TCP) read, or accept() */
854 err = -EAGAIN;
855 if (len <= 0)
856 goto out_release;
857
858 clear_bit(XPT_OLD, &xprt->xpt_flags);
859
860 xprt->xpt_ops->xpo_secure_port(rqstp);
861 rqstp->rq_chandle.defer = svc_defer;
862 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]);
863
864 if (serv->sv_stats)
865 serv->sv_stats->netcnt++;
866 trace_svc_recv(rqstp, len);
867 return len;
868out_release:
869 rqstp->rq_res.len = 0;
870 svc_xprt_release(rqstp);
871out:
872 return err;
873}
874EXPORT_SYMBOL_GPL(svc_recv);
875
876/*
877 * Drop request
878 */
879void svc_drop(struct svc_rqst *rqstp)
880{
881 trace_svc_drop(rqstp);
882 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
883 svc_xprt_release(rqstp);
884}
885EXPORT_SYMBOL_GPL(svc_drop);
886
887/*
888 * Return reply to client.
889 */
890int svc_send(struct svc_rqst *rqstp)
891{
892 struct svc_xprt *xprt;
893 int len = -EFAULT;
894 struct xdr_buf *xb;
895
896 xprt = rqstp->rq_xprt;
897 if (!xprt)
898 goto out;
899
900 /* release the receive skb before sending the reply */
901 xprt->xpt_ops->xpo_release_rqst(rqstp);
902
903 /* calculate over-all length */
904 xb = &rqstp->rq_res;
905 xb->len = xb->head[0].iov_len +
906 xb->page_len +
907 xb->tail[0].iov_len;
908
909 /* Grab mutex to serialize outgoing data. */
910 mutex_lock(&xprt->xpt_mutex);
911 trace_svc_stats_latency(rqstp);
912 if (test_bit(XPT_DEAD, &xprt->xpt_flags)
913 || test_bit(XPT_CLOSE, &xprt->xpt_flags))
914 len = -ENOTCONN;
915 else
916 len = xprt->xpt_ops->xpo_sendto(rqstp);
917 mutex_unlock(&xprt->xpt_mutex);
918 trace_svc_send(rqstp, len);
919 svc_xprt_release(rqstp);
920
921 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
922 len = 0;
923out:
924 return len;
925}
926
927/*
928 * Timer function to close old temporary transports, using
929 * a mark-and-sweep algorithm.
930 */
931static void svc_age_temp_xprts(struct timer_list *t)
932{
933 struct svc_serv *serv = from_timer(serv, t, sv_temptimer);
934 struct svc_xprt *xprt;
935 struct list_head *le, *next;
936
937 dprintk("svc_age_temp_xprts\n");
938
939 if (!spin_trylock_bh(&serv->sv_lock)) {
940 /* busy, try again 1 sec later */
941 dprintk("svc_age_temp_xprts: busy\n");
942 mod_timer(&serv->sv_temptimer, jiffies + HZ);
943 return;
944 }
945
946 list_for_each_safe(le, next, &serv->sv_tempsocks) {
947 xprt = list_entry(le, struct svc_xprt, xpt_list);
948
949 /* First time through, just mark it OLD. Second time
950 * through, close it. */
951 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
952 continue;
953 if (kref_read(&xprt->xpt_ref) > 1 ||
954 test_bit(XPT_BUSY, &xprt->xpt_flags))
955 continue;
956 list_del_init(le);
957 set_bit(XPT_CLOSE, &xprt->xpt_flags);
958 dprintk("queuing xprt %p for closing\n", xprt);
959
960 /* a thread will dequeue and close it soon */
961 svc_xprt_enqueue(xprt);
962 }
963 spin_unlock_bh(&serv->sv_lock);
964
965 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
966}
967
968/* Close temporary transports whose xpt_local matches server_addr immediately
969 * instead of waiting for them to be picked up by the timer.
970 *
971 * This is meant to be called from a notifier_block that runs when an ip
972 * address is deleted.
973 */
974void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr)
975{
976 struct svc_xprt *xprt;
977 struct list_head *le, *next;
978 LIST_HEAD(to_be_closed);
979
980 spin_lock_bh(&serv->sv_lock);
981 list_for_each_safe(le, next, &serv->sv_tempsocks) {
982 xprt = list_entry(le, struct svc_xprt, xpt_list);
983 if (rpc_cmp_addr(server_addr, (struct sockaddr *)
984 &xprt->xpt_local)) {
985 dprintk("svc_age_temp_xprts_now: found %p\n", xprt);
986 list_move(le, &to_be_closed);
987 }
988 }
989 spin_unlock_bh(&serv->sv_lock);
990
991 while (!list_empty(&to_be_closed)) {
992 le = to_be_closed.next;
993 list_del_init(le);
994 xprt = list_entry(le, struct svc_xprt, xpt_list);
995 set_bit(XPT_CLOSE, &xprt->xpt_flags);
996 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags);
997 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
998 xprt);
999 svc_xprt_enqueue(xprt);
1000 }
1001}
1002EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);
1003
1004static void call_xpt_users(struct svc_xprt *xprt)
1005{
1006 struct svc_xpt_user *u;
1007
1008 spin_lock(&xprt->xpt_lock);
1009 while (!list_empty(&xprt->xpt_users)) {
1010 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
1011 list_del_init(&u->list);
1012 u->callback(u);
1013 }
1014 spin_unlock(&xprt->xpt_lock);
1015}
1016
1017/*
1018 * Remove a dead transport
1019 */
1020static void svc_delete_xprt(struct svc_xprt *xprt)
1021{
1022 struct svc_serv *serv = xprt->xpt_server;
1023 struct svc_deferred_req *dr;
1024
1025 /* Only do this once */
1026 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
1027 BUG();
1028
1029 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
1030 xprt->xpt_ops->xpo_detach(xprt);
1031
1032 spin_lock_bh(&serv->sv_lock);
1033 list_del_init(&xprt->xpt_list);
1034 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready));
1035 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
1036 serv->sv_tmpcnt--;
1037 spin_unlock_bh(&serv->sv_lock);
1038
1039 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
1040 kfree(dr);
1041
1042 call_xpt_users(xprt);
1043 svc_xprt_put(xprt);
1044}
1045
1046void svc_close_xprt(struct svc_xprt *xprt)
1047{
1048 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1049 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
1050 /* someone else will have to effect the close */
1051 return;
1052 /*
1053 * We expect svc_close_xprt() to work even when no threads are
1054 * running (e.g., while configuring the server before starting
1055 * any threads), so if the transport isn't busy, we delete
1056 * it ourself:
1057 */
1058 svc_delete_xprt(xprt);
1059}
1060EXPORT_SYMBOL_GPL(svc_close_xprt);
1061
1062static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net)
1063{
1064 struct svc_xprt *xprt;
1065 int ret = 0;
1066
1067 spin_lock(&serv->sv_lock);
1068 list_for_each_entry(xprt, xprt_list, xpt_list) {
1069 if (xprt->xpt_net != net)
1070 continue;
1071 ret++;
1072 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1073 svc_xprt_enqueue(xprt);
1074 }
1075 spin_unlock(&serv->sv_lock);
1076 return ret;
1077}
1078
1079static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net)
1080{
1081 struct svc_pool *pool;
1082 struct svc_xprt *xprt;
1083 struct svc_xprt *tmp;
1084 int i;
1085
1086 for (i = 0; i < serv->sv_nrpools; i++) {
1087 pool = &serv->sv_pools[i];
1088
1089 spin_lock_bh(&pool->sp_lock);
1090 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) {
1091 if (xprt->xpt_net != net)
1092 continue;
1093 list_del_init(&xprt->xpt_ready);
1094 spin_unlock_bh(&pool->sp_lock);
1095 return xprt;
1096 }
1097 spin_unlock_bh(&pool->sp_lock);
1098 }
1099 return NULL;
1100}
1101
1102static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
1103{
1104 struct svc_xprt *xprt;
1105
1106 while ((xprt = svc_dequeue_net(serv, net))) {
1107 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1108 svc_delete_xprt(xprt);
1109 }
1110}
1111
1112/*
1113 * Server threads may still be running (especially in the case where the
1114 * service is still running in other network namespaces).
1115 *
1116 * So we shut down sockets the same way we would on a running server, by
1117 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do
1118 * the close. In the case there are no such other threads,
1119 * threads running, svc_clean_up_xprts() does a simple version of a
1120 * server's main event loop, and in the case where there are other
1121 * threads, we may need to wait a little while and then check again to
1122 * see if they're done.
1123 */
1124void svc_close_net(struct svc_serv *serv, struct net *net)
1125{
1126 int delay = 0;
1127
1128 while (svc_close_list(serv, &serv->sv_permsocks, net) +
1129 svc_close_list(serv, &serv->sv_tempsocks, net)) {
1130
1131 svc_clean_up_xprts(serv, net);
1132 msleep(delay++);
1133 }
1134}
1135
1136/*
1137 * Handle defer and revisit of requests
1138 */
1139
1140static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
1141{
1142 struct svc_deferred_req *dr =
1143 container_of(dreq, struct svc_deferred_req, handle);
1144 struct svc_xprt *xprt = dr->xprt;
1145
1146 spin_lock(&xprt->xpt_lock);
1147 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
1148 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
1149 spin_unlock(&xprt->xpt_lock);
1150 dprintk("revisit canceled\n");
1151 svc_xprt_put(xprt);
1152 trace_svc_drop_deferred(dr);
1153 kfree(dr);
1154 return;
1155 }
1156 dprintk("revisit queued\n");
1157 dr->xprt = NULL;
1158 list_add(&dr->handle.recent, &xprt->xpt_deferred);
1159 spin_unlock(&xprt->xpt_lock);
1160 svc_xprt_enqueue(xprt);
1161 svc_xprt_put(xprt);
1162}
1163
1164/*
1165 * Save the request off for later processing. The request buffer looks
1166 * like this:
1167 *
1168 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1169 *
1170 * This code can only handle requests that consist of an xprt-header
1171 * and rpc-header.
1172 */
1173static struct cache_deferred_req *svc_defer(struct cache_req *req)
1174{
1175 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1176 struct svc_deferred_req *dr;
1177
1178 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags))
1179 return NULL; /* if more than a page, give up FIXME */
1180 if (rqstp->rq_deferred) {
1181 dr = rqstp->rq_deferred;
1182 rqstp->rq_deferred = NULL;
1183 } else {
1184 size_t skip;
1185 size_t size;
1186 /* FIXME maybe discard if size too large */
1187 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
1188 dr = kmalloc(size, GFP_KERNEL);
1189 if (dr == NULL)
1190 return NULL;
1191
1192 dr->handle.owner = rqstp->rq_server;
1193 dr->prot = rqstp->rq_prot;
1194 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1195 dr->addrlen = rqstp->rq_addrlen;
1196 dr->daddr = rqstp->rq_daddr;
1197 dr->argslen = rqstp->rq_arg.len >> 2;
1198 dr->xprt_hlen = rqstp->rq_xprt_hlen;
1199
1200 /* back up head to the start of the buffer and copy */
1201 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1202 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1203 dr->argslen << 2);
1204 }
1205 svc_xprt_get(rqstp->rq_xprt);
1206 dr->xprt = rqstp->rq_xprt;
1207 set_bit(RQ_DROPME, &rqstp->rq_flags);
1208
1209 dr->handle.revisit = svc_revisit;
1210 trace_svc_defer(rqstp);
1211 return &dr->handle;
1212}
1213
1214/*
1215 * recv data from a deferred request into an active one
1216 */
1217static int svc_deferred_recv(struct svc_rqst *rqstp)
1218{
1219 struct svc_deferred_req *dr = rqstp->rq_deferred;
1220
1221 /* setup iov_base past transport header */
1222 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1223 /* The iov_len does not include the transport header bytes */
1224 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
1225 rqstp->rq_arg.page_len = 0;
1226 /* The rq_arg.len includes the transport header bytes */
1227 rqstp->rq_arg.len = dr->argslen<<2;
1228 rqstp->rq_prot = dr->prot;
1229 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1230 rqstp->rq_addrlen = dr->addrlen;
1231 /* Save off transport header len in case we get deferred again */
1232 rqstp->rq_xprt_hlen = dr->xprt_hlen;
1233 rqstp->rq_daddr = dr->daddr;
1234 rqstp->rq_respages = rqstp->rq_pages;
1235 return (dr->argslen<<2) - dr->xprt_hlen;
1236}
1237
1238
1239static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1240{
1241 struct svc_deferred_req *dr = NULL;
1242
1243 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1244 return NULL;
1245 spin_lock(&xprt->xpt_lock);
1246 if (!list_empty(&xprt->xpt_deferred)) {
1247 dr = list_entry(xprt->xpt_deferred.next,
1248 struct svc_deferred_req,
1249 handle.recent);
1250 list_del_init(&dr->handle.recent);
1251 trace_svc_revisit_deferred(dr);
1252 } else
1253 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1254 spin_unlock(&xprt->xpt_lock);
1255 return dr;
1256}
1257
1258/**
1259 * svc_find_xprt - find an RPC transport instance
1260 * @serv: pointer to svc_serv to search
1261 * @xcl_name: C string containing transport's class name
1262 * @net: owner net pointer
1263 * @af: Address family of transport's local address
1264 * @port: transport's IP port number
1265 *
1266 * Return the transport instance pointer for the endpoint accepting
1267 * connections/peer traffic from the specified transport class,
1268 * address family and port.
1269 *
1270 * Specifying 0 for the address family or port is effectively a
1271 * wild-card, and will result in matching the first transport in the
1272 * service's list that has a matching class name.
1273 */
1274struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1275 struct net *net, const sa_family_t af,
1276 const unsigned short port)
1277{
1278 struct svc_xprt *xprt;
1279 struct svc_xprt *found = NULL;
1280
1281 /* Sanity check the args */
1282 if (serv == NULL || xcl_name == NULL)
1283 return found;
1284
1285 spin_lock_bh(&serv->sv_lock);
1286 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1287 if (xprt->xpt_net != net)
1288 continue;
1289 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1290 continue;
1291 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1292 continue;
1293 if (port != 0 && port != svc_xprt_local_port(xprt))
1294 continue;
1295 found = xprt;
1296 svc_xprt_get(xprt);
1297 break;
1298 }
1299 spin_unlock_bh(&serv->sv_lock);
1300 return found;
1301}
1302EXPORT_SYMBOL_GPL(svc_find_xprt);
1303
1304static int svc_one_xprt_name(const struct svc_xprt *xprt,
1305 char *pos, int remaining)
1306{
1307 int len;
1308
1309 len = snprintf(pos, remaining, "%s %u\n",
1310 xprt->xpt_class->xcl_name,
1311 svc_xprt_local_port(xprt));
1312 if (len >= remaining)
1313 return -ENAMETOOLONG;
1314 return len;
1315}
1316
1317/**
1318 * svc_xprt_names - format a buffer with a list of transport names
1319 * @serv: pointer to an RPC service
1320 * @buf: pointer to a buffer to be filled in
1321 * @buflen: length of buffer to be filled in
1322 *
1323 * Fills in @buf with a string containing a list of transport names,
1324 * each name terminated with '\n'.
1325 *
1326 * Returns positive length of the filled-in string on success; otherwise
1327 * a negative errno value is returned if an error occurs.
1328 */
1329int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1330{
1331 struct svc_xprt *xprt;
1332 int len, totlen;
1333 char *pos;
1334
1335 /* Sanity check args */
1336 if (!serv)
1337 return 0;
1338
1339 spin_lock_bh(&serv->sv_lock);
1340
1341 pos = buf;
1342 totlen = 0;
1343 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1344 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1345 if (len < 0) {
1346 *buf = '\0';
1347 totlen = len;
1348 }
1349 if (len <= 0)
1350 break;
1351
1352 pos += len;
1353 totlen += len;
1354 }
1355
1356 spin_unlock_bh(&serv->sv_lock);
1357 return totlen;
1358}
1359EXPORT_SYMBOL_GPL(svc_xprt_names);
1360
1361
1362/*----------------------------------------------------------------------------*/
1363
1364static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1365{
1366 unsigned int pidx = (unsigned int)*pos;
1367 struct svc_serv *serv = m->private;
1368
1369 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1370
1371 if (!pidx)
1372 return SEQ_START_TOKEN;
1373 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1374}
1375
1376static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1377{
1378 struct svc_pool *pool = p;
1379 struct svc_serv *serv = m->private;
1380
1381 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1382
1383 if (p == SEQ_START_TOKEN) {
1384 pool = &serv->sv_pools[0];
1385 } else {
1386 unsigned int pidx = (pool - &serv->sv_pools[0]);
1387 if (pidx < serv->sv_nrpools-1)
1388 pool = &serv->sv_pools[pidx+1];
1389 else
1390 pool = NULL;
1391 }
1392 ++*pos;
1393 return pool;
1394}
1395
1396static void svc_pool_stats_stop(struct seq_file *m, void *p)
1397{
1398}
1399
1400static int svc_pool_stats_show(struct seq_file *m, void *p)
1401{
1402 struct svc_pool *pool = p;
1403
1404 if (p == SEQ_START_TOKEN) {
1405 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1406 return 0;
1407 }
1408
1409 seq_printf(m, "%u %lu %lu %lu %lu\n",
1410 pool->sp_id,
1411 (unsigned long)atomic_long_read(&pool->sp_stats.packets),
1412 pool->sp_stats.sockets_queued,
1413 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken),
1414 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout));
1415
1416 return 0;
1417}
1418
1419static const struct seq_operations svc_pool_stats_seq_ops = {
1420 .start = svc_pool_stats_start,
1421 .next = svc_pool_stats_next,
1422 .stop = svc_pool_stats_stop,
1423 .show = svc_pool_stats_show,
1424};
1425
1426int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1427{
1428 int err;
1429
1430 err = seq_open(file, &svc_pool_stats_seq_ops);
1431 if (!err)
1432 ((struct seq_file *) file->private_data)->private = serv;
1433 return err;
1434}
1435EXPORT_SYMBOL(svc_pool_stats_open);
1436
1437/*----------------------------------------------------------------------------*/
1/*
2 * linux/net/sunrpc/svc_xprt.c
3 *
4 * Author: Tom Tucker <tom@opengridcomputing.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/errno.h>
9#include <linux/freezer.h>
10#include <linux/kthread.h>
11#include <linux/slab.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>
16#include <linux/sunrpc/xprt.h>
17
18#define RPCDBG_FACILITY RPCDBG_SVCXPRT
19
20static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
21static int svc_deferred_recv(struct svc_rqst *rqstp);
22static struct cache_deferred_req *svc_defer(struct cache_req *req);
23static void svc_age_temp_xprts(unsigned long closure);
24
25/* apparently the "standard" is that clients close
26 * idle connections after 5 minutes, servers after
27 * 6 minutes
28 * http://www.connectathon.org/talks96/nfstcp.pdf
29 */
30static int svc_conn_age_period = 6*60;
31
32/* List of registered transport classes */
33static DEFINE_SPINLOCK(svc_xprt_class_lock);
34static LIST_HEAD(svc_xprt_class_list);
35
36/* SMP locking strategy:
37 *
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.
44 *
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.
49 *
50 * Some flags can be set to certain values at any time
51 * providing that certain rules are followed:
52 *
53 * XPT_CONN, XPT_DATA:
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.
59 * XPT_CLOSE:
60 * - Can set at any time. It is never cleared.
61 * XPT_DEAD:
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.
65 */
66
67int svc_reg_xprt_class(struct svc_xprt_class *xcl)
68{
69 struct svc_xprt_class *cl;
70 int res = -EEXIST;
71
72 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
73
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)
79 goto out;
80 }
81 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
82 res = 0;
83out:
84 spin_unlock(&svc_xprt_class_lock);
85 return res;
86}
87EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
88
89void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
90{
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);
95}
96EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
97
98/*
99 * Format the transport list for printing
100 */
101int svc_print_xprts(char *buf, int maxlen)
102{
103 struct svc_xprt_class *xcl;
104 char tmpstr[80];
105 int len = 0;
106 buf[0] = '\0';
107
108 spin_lock(&svc_xprt_class_lock);
109 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
110 int slen;
111
112 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
113 slen = strlen(tmpstr);
114 if (len + slen > maxlen)
115 break;
116 len += slen;
117 strcat(buf, tmpstr);
118 }
119 spin_unlock(&svc_xprt_class_lock);
120
121 return len;
122}
123
124static void svc_xprt_free(struct kref *kref)
125{
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 /* See comment on corresponding get in xs_setup_bc_tcp(): */
133 if (xprt->xpt_bc_xprt)
134 xprt_put(xprt->xpt_bc_xprt);
135 xprt->xpt_ops->xpo_free(xprt);
136 module_put(owner);
137}
138
139void svc_xprt_put(struct svc_xprt *xprt)
140{
141 kref_put(&xprt->xpt_ref, svc_xprt_free);
142}
143EXPORT_SYMBOL_GPL(svc_xprt_put);
144
145/*
146 * Called by transport drivers to initialize the transport independent
147 * portion of the transport instance.
148 */
149void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
150 struct svc_serv *serv)
151{
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 INIT_LIST_HEAD(&xprt->xpt_users);
161 mutex_init(&xprt->xpt_mutex);
162 spin_lock_init(&xprt->xpt_lock);
163 set_bit(XPT_BUSY, &xprt->xpt_flags);
164 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
165 xprt->xpt_net = get_net(&init_net);
166}
167EXPORT_SYMBOL_GPL(svc_xprt_init);
168
169static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
170 struct svc_serv *serv,
171 struct net *net,
172 const int family,
173 const unsigned short port,
174 int flags)
175{
176 struct sockaddr_in sin = {
177 .sin_family = AF_INET,
178 .sin_addr.s_addr = htonl(INADDR_ANY),
179 .sin_port = htons(port),
180 };
181#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
182 struct sockaddr_in6 sin6 = {
183 .sin6_family = AF_INET6,
184 .sin6_addr = IN6ADDR_ANY_INIT,
185 .sin6_port = htons(port),
186 };
187#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
188 struct sockaddr *sap;
189 size_t len;
190
191 switch (family) {
192 case PF_INET:
193 sap = (struct sockaddr *)&sin;
194 len = sizeof(sin);
195 break;
196#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
197 case PF_INET6:
198 sap = (struct sockaddr *)&sin6;
199 len = sizeof(sin6);
200 break;
201#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
202 default:
203 return ERR_PTR(-EAFNOSUPPORT);
204 }
205
206 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
207}
208
209int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
210 struct net *net, const int family,
211 const unsigned short port, int flags)
212{
213 struct svc_xprt_class *xcl;
214
215 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
216 spin_lock(&svc_xprt_class_lock);
217 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
218 struct svc_xprt *newxprt;
219 unsigned short newport;
220
221 if (strcmp(xprt_name, xcl->xcl_name))
222 continue;
223
224 if (!try_module_get(xcl->xcl_owner))
225 goto err;
226
227 spin_unlock(&svc_xprt_class_lock);
228 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
229 if (IS_ERR(newxprt)) {
230 module_put(xcl->xcl_owner);
231 return PTR_ERR(newxprt);
232 }
233
234 clear_bit(XPT_TEMP, &newxprt->xpt_flags);
235 spin_lock_bh(&serv->sv_lock);
236 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
237 spin_unlock_bh(&serv->sv_lock);
238 newport = svc_xprt_local_port(newxprt);
239 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
240 return newport;
241 }
242 err:
243 spin_unlock(&svc_xprt_class_lock);
244 dprintk("svc: transport %s not found\n", xprt_name);
245
246 /* This errno is exposed to user space. Provide a reasonable
247 * perror msg for a bad transport. */
248 return -EPROTONOSUPPORT;
249}
250EXPORT_SYMBOL_GPL(svc_create_xprt);
251
252/*
253 * Copy the local and remote xprt addresses to the rqstp structure
254 */
255void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
256{
257 struct sockaddr *sin;
258
259 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
260 rqstp->rq_addrlen = xprt->xpt_remotelen;
261
262 /*
263 * Destination address in request is needed for binding the
264 * source address in RPC replies/callbacks later.
265 */
266 sin = (struct sockaddr *)&xprt->xpt_local;
267 switch (sin->sa_family) {
268 case AF_INET:
269 rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
270 break;
271 case AF_INET6:
272 rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
273 break;
274 }
275}
276EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
277
278/**
279 * svc_print_addr - Format rq_addr field for printing
280 * @rqstp: svc_rqst struct containing address to print
281 * @buf: target buffer for formatted address
282 * @len: length of target buffer
283 *
284 */
285char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
286{
287 return __svc_print_addr(svc_addr(rqstp), buf, len);
288}
289EXPORT_SYMBOL_GPL(svc_print_addr);
290
291/*
292 * Queue up an idle server thread. Must have pool->sp_lock held.
293 * Note: this is really a stack rather than a queue, so that we only
294 * use as many different threads as we need, and the rest don't pollute
295 * the cache.
296 */
297static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
298{
299 list_add(&rqstp->rq_list, &pool->sp_threads);
300}
301
302/*
303 * Dequeue an nfsd thread. Must have pool->sp_lock held.
304 */
305static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
306{
307 list_del(&rqstp->rq_list);
308}
309
310static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt)
311{
312 if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE)))
313 return true;
314 if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED)))
315 return xprt->xpt_ops->xpo_has_wspace(xprt);
316 return false;
317}
318
319/*
320 * Queue up a transport with data pending. If there are idle nfsd
321 * processes, wake 'em up.
322 *
323 */
324void svc_xprt_enqueue(struct svc_xprt *xprt)
325{
326 struct svc_serv *serv = xprt->xpt_server;
327 struct svc_pool *pool;
328 struct svc_rqst *rqstp;
329 int cpu;
330
331 if (!svc_xprt_has_something_to_do(xprt))
332 return;
333
334 cpu = get_cpu();
335 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
336 put_cpu();
337
338 spin_lock_bh(&pool->sp_lock);
339
340 if (!list_empty(&pool->sp_threads) &&
341 !list_empty(&pool->sp_sockets))
342 printk(KERN_ERR
343 "svc_xprt_enqueue: "
344 "threads and transports both waiting??\n");
345
346 pool->sp_stats.packets++;
347
348 /* Mark transport as busy. It will remain in this state until
349 * the provider calls svc_xprt_received. We update XPT_BUSY
350 * atomically because it also guards against trying to enqueue
351 * the transport twice.
352 */
353 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
354 /* Don't enqueue transport while already enqueued */
355 dprintk("svc: transport %p busy, not enqueued\n", xprt);
356 goto out_unlock;
357 }
358
359 if (!list_empty(&pool->sp_threads)) {
360 rqstp = list_entry(pool->sp_threads.next,
361 struct svc_rqst,
362 rq_list);
363 dprintk("svc: transport %p served by daemon %p\n",
364 xprt, rqstp);
365 svc_thread_dequeue(pool, rqstp);
366 if (rqstp->rq_xprt)
367 printk(KERN_ERR
368 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
369 rqstp, rqstp->rq_xprt);
370 rqstp->rq_xprt = xprt;
371 svc_xprt_get(xprt);
372 rqstp->rq_reserved = serv->sv_max_mesg;
373 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
374 pool->sp_stats.threads_woken++;
375 wake_up(&rqstp->rq_wait);
376 } else {
377 dprintk("svc: transport %p put into queue\n", xprt);
378 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
379 pool->sp_stats.sockets_queued++;
380 }
381
382out_unlock:
383 spin_unlock_bh(&pool->sp_lock);
384}
385EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
386
387/*
388 * Dequeue the first transport. Must be called with the pool->sp_lock held.
389 */
390static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
391{
392 struct svc_xprt *xprt;
393
394 if (list_empty(&pool->sp_sockets))
395 return NULL;
396
397 xprt = list_entry(pool->sp_sockets.next,
398 struct svc_xprt, xpt_ready);
399 list_del_init(&xprt->xpt_ready);
400
401 dprintk("svc: transport %p dequeued, inuse=%d\n",
402 xprt, atomic_read(&xprt->xpt_ref.refcount));
403
404 return xprt;
405}
406
407/*
408 * svc_xprt_received conditionally queues the transport for processing
409 * by another thread. The caller must hold the XPT_BUSY bit and must
410 * not thereafter touch transport data.
411 *
412 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
413 * insufficient) data.
414 */
415void svc_xprt_received(struct svc_xprt *xprt)
416{
417 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
418 /* As soon as we clear busy, the xprt could be closed and
419 * 'put', so we need a reference to call svc_xprt_enqueue with:
420 */
421 svc_xprt_get(xprt);
422 clear_bit(XPT_BUSY, &xprt->xpt_flags);
423 svc_xprt_enqueue(xprt);
424 svc_xprt_put(xprt);
425}
426EXPORT_SYMBOL_GPL(svc_xprt_received);
427
428/**
429 * svc_reserve - change the space reserved for the reply to a request.
430 * @rqstp: The request in question
431 * @space: new max space to reserve
432 *
433 * Each request reserves some space on the output queue of the transport
434 * to make sure the reply fits. This function reduces that reserved
435 * space to be the amount of space used already, plus @space.
436 *
437 */
438void svc_reserve(struct svc_rqst *rqstp, int space)
439{
440 space += rqstp->rq_res.head[0].iov_len;
441
442 if (space < rqstp->rq_reserved) {
443 struct svc_xprt *xprt = rqstp->rq_xprt;
444 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
445 rqstp->rq_reserved = space;
446
447 svc_xprt_enqueue(xprt);
448 }
449}
450EXPORT_SYMBOL_GPL(svc_reserve);
451
452static void svc_xprt_release(struct svc_rqst *rqstp)
453{
454 struct svc_xprt *xprt = rqstp->rq_xprt;
455
456 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
457
458 kfree(rqstp->rq_deferred);
459 rqstp->rq_deferred = NULL;
460
461 svc_free_res_pages(rqstp);
462 rqstp->rq_res.page_len = 0;
463 rqstp->rq_res.page_base = 0;
464
465 /* Reset response buffer and release
466 * the reservation.
467 * But first, check that enough space was reserved
468 * for the reply, otherwise we have a bug!
469 */
470 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
471 printk(KERN_ERR "RPC request reserved %d but used %d\n",
472 rqstp->rq_reserved,
473 rqstp->rq_res.len);
474
475 rqstp->rq_res.head[0].iov_len = 0;
476 svc_reserve(rqstp, 0);
477 rqstp->rq_xprt = NULL;
478
479 svc_xprt_put(xprt);
480}
481
482/*
483 * External function to wake up a server waiting for data
484 * This really only makes sense for services like lockd
485 * which have exactly one thread anyway.
486 */
487void svc_wake_up(struct svc_serv *serv)
488{
489 struct svc_rqst *rqstp;
490 unsigned int i;
491 struct svc_pool *pool;
492
493 for (i = 0; i < serv->sv_nrpools; i++) {
494 pool = &serv->sv_pools[i];
495
496 spin_lock_bh(&pool->sp_lock);
497 if (!list_empty(&pool->sp_threads)) {
498 rqstp = list_entry(pool->sp_threads.next,
499 struct svc_rqst,
500 rq_list);
501 dprintk("svc: daemon %p woken up.\n", rqstp);
502 /*
503 svc_thread_dequeue(pool, rqstp);
504 rqstp->rq_xprt = NULL;
505 */
506 wake_up(&rqstp->rq_wait);
507 }
508 spin_unlock_bh(&pool->sp_lock);
509 }
510}
511EXPORT_SYMBOL_GPL(svc_wake_up);
512
513int svc_port_is_privileged(struct sockaddr *sin)
514{
515 switch (sin->sa_family) {
516 case AF_INET:
517 return ntohs(((struct sockaddr_in *)sin)->sin_port)
518 < PROT_SOCK;
519 case AF_INET6:
520 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
521 < PROT_SOCK;
522 default:
523 return 0;
524 }
525}
526
527/*
528 * Make sure that we don't have too many active connections. If we have,
529 * something must be dropped. It's not clear what will happen if we allow
530 * "too many" connections, but when dealing with network-facing software,
531 * we have to code defensively. Here we do that by imposing hard limits.
532 *
533 * There's no point in trying to do random drop here for DoS
534 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
535 * attacker can easily beat that.
536 *
537 * The only somewhat efficient mechanism would be if drop old
538 * connections from the same IP first. But right now we don't even
539 * record the client IP in svc_sock.
540 *
541 * single-threaded services that expect a lot of clients will probably
542 * need to set sv_maxconn to override the default value which is based
543 * on the number of threads
544 */
545static void svc_check_conn_limits(struct svc_serv *serv)
546{
547 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
548 (serv->sv_nrthreads+3) * 20;
549
550 if (serv->sv_tmpcnt > limit) {
551 struct svc_xprt *xprt = NULL;
552 spin_lock_bh(&serv->sv_lock);
553 if (!list_empty(&serv->sv_tempsocks)) {
554 if (net_ratelimit()) {
555 /* Try to help the admin */
556 printk(KERN_NOTICE "%s: too many open "
557 "connections, consider increasing %s\n",
558 serv->sv_name, serv->sv_maxconn ?
559 "the max number of connections." :
560 "the number of threads.");
561 }
562 /*
563 * Always select the oldest connection. It's not fair,
564 * but so is life
565 */
566 xprt = list_entry(serv->sv_tempsocks.prev,
567 struct svc_xprt,
568 xpt_list);
569 set_bit(XPT_CLOSE, &xprt->xpt_flags);
570 svc_xprt_get(xprt);
571 }
572 spin_unlock_bh(&serv->sv_lock);
573
574 if (xprt) {
575 svc_xprt_enqueue(xprt);
576 svc_xprt_put(xprt);
577 }
578 }
579}
580
581/*
582 * Receive the next request on any transport. This code is carefully
583 * organised not to touch any cachelines in the shared svc_serv
584 * structure, only cachelines in the local svc_pool.
585 */
586int svc_recv(struct svc_rqst *rqstp, long timeout)
587{
588 struct svc_xprt *xprt = NULL;
589 struct svc_serv *serv = rqstp->rq_server;
590 struct svc_pool *pool = rqstp->rq_pool;
591 int len, i;
592 int pages;
593 struct xdr_buf *arg;
594 DECLARE_WAITQUEUE(wait, current);
595 long time_left;
596
597 dprintk("svc: server %p waiting for data (to = %ld)\n",
598 rqstp, timeout);
599
600 if (rqstp->rq_xprt)
601 printk(KERN_ERR
602 "svc_recv: service %p, transport not NULL!\n",
603 rqstp);
604 if (waitqueue_active(&rqstp->rq_wait))
605 printk(KERN_ERR
606 "svc_recv: service %p, wait queue active!\n",
607 rqstp);
608
609 /* now allocate needed pages. If we get a failure, sleep briefly */
610 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
611 for (i = 0; i < pages ; i++)
612 while (rqstp->rq_pages[i] == NULL) {
613 struct page *p = alloc_page(GFP_KERNEL);
614 if (!p) {
615 set_current_state(TASK_INTERRUPTIBLE);
616 if (signalled() || kthread_should_stop()) {
617 set_current_state(TASK_RUNNING);
618 return -EINTR;
619 }
620 schedule_timeout(msecs_to_jiffies(500));
621 }
622 rqstp->rq_pages[i] = p;
623 }
624 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
625 BUG_ON(pages >= RPCSVC_MAXPAGES);
626
627 /* Make arg->head point to first page and arg->pages point to rest */
628 arg = &rqstp->rq_arg;
629 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
630 arg->head[0].iov_len = PAGE_SIZE;
631 arg->pages = rqstp->rq_pages + 1;
632 arg->page_base = 0;
633 /* save at least one page for response */
634 arg->page_len = (pages-2)*PAGE_SIZE;
635 arg->len = (pages-1)*PAGE_SIZE;
636 arg->tail[0].iov_len = 0;
637
638 try_to_freeze();
639 cond_resched();
640 if (signalled() || kthread_should_stop())
641 return -EINTR;
642
643 /* Normally we will wait up to 5 seconds for any required
644 * cache information to be provided.
645 */
646 rqstp->rq_chandle.thread_wait = 5*HZ;
647
648 spin_lock_bh(&pool->sp_lock);
649 xprt = svc_xprt_dequeue(pool);
650 if (xprt) {
651 rqstp->rq_xprt = xprt;
652 svc_xprt_get(xprt);
653 rqstp->rq_reserved = serv->sv_max_mesg;
654 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
655
656 /* As there is a shortage of threads and this request
657 * had to be queued, don't allow the thread to wait so
658 * long for cache updates.
659 */
660 rqstp->rq_chandle.thread_wait = 1*HZ;
661 } else {
662 /* No data pending. Go to sleep */
663 svc_thread_enqueue(pool, rqstp);
664
665 /*
666 * We have to be able to interrupt this wait
667 * to bring down the daemons ...
668 */
669 set_current_state(TASK_INTERRUPTIBLE);
670
671 /*
672 * checking kthread_should_stop() here allows us to avoid
673 * locking and signalling when stopping kthreads that call
674 * svc_recv. If the thread has already been woken up, then
675 * we can exit here without sleeping. If not, then it
676 * it'll be woken up quickly during the schedule_timeout
677 */
678 if (kthread_should_stop()) {
679 set_current_state(TASK_RUNNING);
680 spin_unlock_bh(&pool->sp_lock);
681 return -EINTR;
682 }
683
684 add_wait_queue(&rqstp->rq_wait, &wait);
685 spin_unlock_bh(&pool->sp_lock);
686
687 time_left = schedule_timeout(timeout);
688
689 try_to_freeze();
690
691 spin_lock_bh(&pool->sp_lock);
692 remove_wait_queue(&rqstp->rq_wait, &wait);
693 if (!time_left)
694 pool->sp_stats.threads_timedout++;
695
696 xprt = rqstp->rq_xprt;
697 if (!xprt) {
698 svc_thread_dequeue(pool, rqstp);
699 spin_unlock_bh(&pool->sp_lock);
700 dprintk("svc: server %p, no data yet\n", rqstp);
701 if (signalled() || kthread_should_stop())
702 return -EINTR;
703 else
704 return -EAGAIN;
705 }
706 }
707 spin_unlock_bh(&pool->sp_lock);
708
709 len = 0;
710 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
711 dprintk("svc_recv: found XPT_CLOSE\n");
712 svc_delete_xprt(xprt);
713 /* Leave XPT_BUSY set on the dead xprt: */
714 goto out;
715 }
716 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
717 struct svc_xprt *newxpt;
718 newxpt = xprt->xpt_ops->xpo_accept(xprt);
719 if (newxpt) {
720 /*
721 * We know this module_get will succeed because the
722 * listener holds a reference too
723 */
724 __module_get(newxpt->xpt_class->xcl_owner);
725 svc_check_conn_limits(xprt->xpt_server);
726 spin_lock_bh(&serv->sv_lock);
727 set_bit(XPT_TEMP, &newxpt->xpt_flags);
728 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
729 serv->sv_tmpcnt++;
730 if (serv->sv_temptimer.function == NULL) {
731 /* setup timer to age temp transports */
732 setup_timer(&serv->sv_temptimer,
733 svc_age_temp_xprts,
734 (unsigned long)serv);
735 mod_timer(&serv->sv_temptimer,
736 jiffies + svc_conn_age_period * HZ);
737 }
738 spin_unlock_bh(&serv->sv_lock);
739 svc_xprt_received(newxpt);
740 }
741 } else if (xprt->xpt_ops->xpo_has_wspace(xprt)) {
742 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
743 rqstp, pool->sp_id, xprt,
744 atomic_read(&xprt->xpt_ref.refcount));
745 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
746 if (rqstp->rq_deferred)
747 len = svc_deferred_recv(rqstp);
748 else
749 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
750 dprintk("svc: got len=%d\n", len);
751 }
752 svc_xprt_received(xprt);
753
754 /* No data, incomplete (TCP) read, or accept() */
755 if (len == 0 || len == -EAGAIN)
756 goto out;
757
758 clear_bit(XPT_OLD, &xprt->xpt_flags);
759
760 rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
761 rqstp->rq_chandle.defer = svc_defer;
762
763 if (serv->sv_stats)
764 serv->sv_stats->netcnt++;
765 return len;
766out:
767 rqstp->rq_res.len = 0;
768 svc_xprt_release(rqstp);
769 return -EAGAIN;
770}
771EXPORT_SYMBOL_GPL(svc_recv);
772
773/*
774 * Drop request
775 */
776void svc_drop(struct svc_rqst *rqstp)
777{
778 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
779 svc_xprt_release(rqstp);
780}
781EXPORT_SYMBOL_GPL(svc_drop);
782
783/*
784 * Return reply to client.
785 */
786int svc_send(struct svc_rqst *rqstp)
787{
788 struct svc_xprt *xprt;
789 int len;
790 struct xdr_buf *xb;
791
792 xprt = rqstp->rq_xprt;
793 if (!xprt)
794 return -EFAULT;
795
796 /* release the receive skb before sending the reply */
797 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
798
799 /* calculate over-all length */
800 xb = &rqstp->rq_res;
801 xb->len = xb->head[0].iov_len +
802 xb->page_len +
803 xb->tail[0].iov_len;
804
805 /* Grab mutex to serialize outgoing data. */
806 mutex_lock(&xprt->xpt_mutex);
807 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
808 len = -ENOTCONN;
809 else
810 len = xprt->xpt_ops->xpo_sendto(rqstp);
811 mutex_unlock(&xprt->xpt_mutex);
812 rpc_wake_up(&xprt->xpt_bc_pending);
813 svc_xprt_release(rqstp);
814
815 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
816 return 0;
817 return len;
818}
819
820/*
821 * Timer function to close old temporary transports, using
822 * a mark-and-sweep algorithm.
823 */
824static void svc_age_temp_xprts(unsigned long closure)
825{
826 struct svc_serv *serv = (struct svc_serv *)closure;
827 struct svc_xprt *xprt;
828 struct list_head *le, *next;
829 LIST_HEAD(to_be_aged);
830
831 dprintk("svc_age_temp_xprts\n");
832
833 if (!spin_trylock_bh(&serv->sv_lock)) {
834 /* busy, try again 1 sec later */
835 dprintk("svc_age_temp_xprts: busy\n");
836 mod_timer(&serv->sv_temptimer, jiffies + HZ);
837 return;
838 }
839
840 list_for_each_safe(le, next, &serv->sv_tempsocks) {
841 xprt = list_entry(le, struct svc_xprt, xpt_list);
842
843 /* First time through, just mark it OLD. Second time
844 * through, close it. */
845 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
846 continue;
847 if (atomic_read(&xprt->xpt_ref.refcount) > 1 ||
848 test_bit(XPT_BUSY, &xprt->xpt_flags))
849 continue;
850 svc_xprt_get(xprt);
851 list_move(le, &to_be_aged);
852 set_bit(XPT_CLOSE, &xprt->xpt_flags);
853 set_bit(XPT_DETACHED, &xprt->xpt_flags);
854 }
855 spin_unlock_bh(&serv->sv_lock);
856
857 while (!list_empty(&to_be_aged)) {
858 le = to_be_aged.next;
859 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
860 list_del_init(le);
861 xprt = list_entry(le, struct svc_xprt, xpt_list);
862
863 dprintk("queuing xprt %p for closing\n", xprt);
864
865 /* a thread will dequeue and close it soon */
866 svc_xprt_enqueue(xprt);
867 svc_xprt_put(xprt);
868 }
869
870 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
871}
872
873static void call_xpt_users(struct svc_xprt *xprt)
874{
875 struct svc_xpt_user *u;
876
877 spin_lock(&xprt->xpt_lock);
878 while (!list_empty(&xprt->xpt_users)) {
879 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
880 list_del(&u->list);
881 u->callback(u);
882 }
883 spin_unlock(&xprt->xpt_lock);
884}
885
886/*
887 * Remove a dead transport
888 */
889void svc_delete_xprt(struct svc_xprt *xprt)
890{
891 struct svc_serv *serv = xprt->xpt_server;
892 struct svc_deferred_req *dr;
893
894 /* Only do this once */
895 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
896 BUG();
897
898 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
899 xprt->xpt_ops->xpo_detach(xprt);
900
901 spin_lock_bh(&serv->sv_lock);
902 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
903 list_del_init(&xprt->xpt_list);
904 /*
905 * The only time we're called while xpt_ready is still on a list
906 * is while the list itself is about to be destroyed (in
907 * svc_destroy). BUT svc_xprt_enqueue could still be attempting
908 * to add new entries to the sp_sockets list, so we can't leave
909 * a freed xprt on it.
910 */
911 list_del_init(&xprt->xpt_ready);
912 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
913 serv->sv_tmpcnt--;
914 spin_unlock_bh(&serv->sv_lock);
915
916 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
917 kfree(dr);
918
919 call_xpt_users(xprt);
920 svc_xprt_put(xprt);
921}
922
923void svc_close_xprt(struct svc_xprt *xprt)
924{
925 set_bit(XPT_CLOSE, &xprt->xpt_flags);
926 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
927 /* someone else will have to effect the close */
928 return;
929 /*
930 * We expect svc_close_xprt() to work even when no threads are
931 * running (e.g., while configuring the server before starting
932 * any threads), so if the transport isn't busy, we delete
933 * it ourself:
934 */
935 svc_delete_xprt(xprt);
936}
937EXPORT_SYMBOL_GPL(svc_close_xprt);
938
939void svc_close_all(struct list_head *xprt_list)
940{
941 struct svc_xprt *xprt;
942 struct svc_xprt *tmp;
943
944 /*
945 * The server is shutting down, and no more threads are running.
946 * svc_xprt_enqueue() might still be running, but at worst it
947 * will re-add the xprt to sp_sockets, which will soon get
948 * freed. So we don't bother with any more locking, and don't
949 * leave the close to the (nonexistent) server threads:
950 */
951 list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
952 set_bit(XPT_CLOSE, &xprt->xpt_flags);
953 svc_delete_xprt(xprt);
954 }
955}
956
957/*
958 * Handle defer and revisit of requests
959 */
960
961static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
962{
963 struct svc_deferred_req *dr =
964 container_of(dreq, struct svc_deferred_req, handle);
965 struct svc_xprt *xprt = dr->xprt;
966
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");
972 svc_xprt_put(xprt);
973 kfree(dr);
974 return;
975 }
976 dprintk("revisit queued\n");
977 dr->xprt = NULL;
978 list_add(&dr->handle.recent, &xprt->xpt_deferred);
979 spin_unlock(&xprt->xpt_lock);
980 svc_xprt_enqueue(xprt);
981 svc_xprt_put(xprt);
982}
983
984/*
985 * Save the request off for later processing. The request buffer looks
986 * like this:
987 *
988 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
989 *
990 * This code can only handle requests that consist of an xprt-header
991 * and rpc-header.
992 */
993static struct cache_deferred_req *svc_defer(struct cache_req *req)
994{
995 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
996 struct svc_deferred_req *dr;
997
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;
1003 } else {
1004 size_t skip;
1005 size_t size;
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);
1009 if (dr == NULL)
1010 return NULL;
1011
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;
1019
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,
1023 dr->argslen << 2);
1024 }
1025 svc_xprt_get(rqstp->rq_xprt);
1026 dr->xprt = rqstp->rq_xprt;
1027 rqstp->rq_dropme = true;
1028
1029 dr->handle.revisit = svc_revisit;
1030 return &dr->handle;
1031}
1032
1033/*
1034 * recv data from a deferred request into an active one
1035 */
1036static int svc_deferred_recv(struct svc_rqst *rqstp)
1037{
1038 struct svc_deferred_req *dr = rqstp->rq_deferred;
1039
1040 /* setup iov_base past transport header */
1041 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1042 /* The iov_len does not include the transport header bytes */
1043 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
1044 rqstp->rq_arg.page_len = 0;
1045 /* The rq_arg.len includes the transport header bytes */
1046 rqstp->rq_arg.len = dr->argslen<<2;
1047 rqstp->rq_prot = dr->prot;
1048 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1049 rqstp->rq_addrlen = dr->addrlen;
1050 /* Save off transport header len in case we get deferred again */
1051 rqstp->rq_xprt_hlen = dr->xprt_hlen;
1052 rqstp->rq_daddr = dr->daddr;
1053 rqstp->rq_respages = rqstp->rq_pages;
1054 return (dr->argslen<<2) - dr->xprt_hlen;
1055}
1056
1057
1058static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1059{
1060 struct svc_deferred_req *dr = NULL;
1061
1062 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1063 return NULL;
1064 spin_lock(&xprt->xpt_lock);
1065 if (!list_empty(&xprt->xpt_deferred)) {
1066 dr = list_entry(xprt->xpt_deferred.next,
1067 struct svc_deferred_req,
1068 handle.recent);
1069 list_del_init(&dr->handle.recent);
1070 } else
1071 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1072 spin_unlock(&xprt->xpt_lock);
1073 return dr;
1074}
1075
1076/**
1077 * svc_find_xprt - find an RPC transport instance
1078 * @serv: pointer to svc_serv to search
1079 * @xcl_name: C string containing transport's class name
1080 * @af: Address family of transport's local address
1081 * @port: transport's IP port number
1082 *
1083 * Return the transport instance pointer for the endpoint accepting
1084 * connections/peer traffic from the specified transport class,
1085 * address family and port.
1086 *
1087 * Specifying 0 for the address family or port is effectively a
1088 * wild-card, and will result in matching the first transport in the
1089 * service's list that has a matching class name.
1090 */
1091struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1092 const sa_family_t af, const unsigned short port)
1093{
1094 struct svc_xprt *xprt;
1095 struct svc_xprt *found = NULL;
1096
1097 /* Sanity check the args */
1098 if (serv == NULL || xcl_name == NULL)
1099 return found;
1100
1101 spin_lock_bh(&serv->sv_lock);
1102 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1103 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1104 continue;
1105 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1106 continue;
1107 if (port != 0 && port != svc_xprt_local_port(xprt))
1108 continue;
1109 found = xprt;
1110 svc_xprt_get(xprt);
1111 break;
1112 }
1113 spin_unlock_bh(&serv->sv_lock);
1114 return found;
1115}
1116EXPORT_SYMBOL_GPL(svc_find_xprt);
1117
1118static int svc_one_xprt_name(const struct svc_xprt *xprt,
1119 char *pos, int remaining)
1120{
1121 int len;
1122
1123 len = snprintf(pos, remaining, "%s %u\n",
1124 xprt->xpt_class->xcl_name,
1125 svc_xprt_local_port(xprt));
1126 if (len >= remaining)
1127 return -ENAMETOOLONG;
1128 return len;
1129}
1130
1131/**
1132 * svc_xprt_names - format a buffer with a list of transport names
1133 * @serv: pointer to an RPC service
1134 * @buf: pointer to a buffer to be filled in
1135 * @buflen: length of buffer to be filled in
1136 *
1137 * Fills in @buf with a string containing a list of transport names,
1138 * each name terminated with '\n'.
1139 *
1140 * Returns positive length of the filled-in string on success; otherwise
1141 * a negative errno value is returned if an error occurs.
1142 */
1143int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1144{
1145 struct svc_xprt *xprt;
1146 int len, totlen;
1147 char *pos;
1148
1149 /* Sanity check args */
1150 if (!serv)
1151 return 0;
1152
1153 spin_lock_bh(&serv->sv_lock);
1154
1155 pos = buf;
1156 totlen = 0;
1157 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1158 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1159 if (len < 0) {
1160 *buf = '\0';
1161 totlen = len;
1162 }
1163 if (len <= 0)
1164 break;
1165
1166 pos += len;
1167 totlen += len;
1168 }
1169
1170 spin_unlock_bh(&serv->sv_lock);
1171 return totlen;
1172}
1173EXPORT_SYMBOL_GPL(svc_xprt_names);
1174
1175
1176/*----------------------------------------------------------------------------*/
1177
1178static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1179{
1180 unsigned int pidx = (unsigned int)*pos;
1181 struct svc_serv *serv = m->private;
1182
1183 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1184
1185 if (!pidx)
1186 return SEQ_START_TOKEN;
1187 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1188}
1189
1190static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1191{
1192 struct svc_pool *pool = p;
1193 struct svc_serv *serv = m->private;
1194
1195 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1196
1197 if (p == SEQ_START_TOKEN) {
1198 pool = &serv->sv_pools[0];
1199 } else {
1200 unsigned int pidx = (pool - &serv->sv_pools[0]);
1201 if (pidx < serv->sv_nrpools-1)
1202 pool = &serv->sv_pools[pidx+1];
1203 else
1204 pool = NULL;
1205 }
1206 ++*pos;
1207 return pool;
1208}
1209
1210static void svc_pool_stats_stop(struct seq_file *m, void *p)
1211{
1212}
1213
1214static int svc_pool_stats_show(struct seq_file *m, void *p)
1215{
1216 struct svc_pool *pool = p;
1217
1218 if (p == SEQ_START_TOKEN) {
1219 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1220 return 0;
1221 }
1222
1223 seq_printf(m, "%u %lu %lu %lu %lu\n",
1224 pool->sp_id,
1225 pool->sp_stats.packets,
1226 pool->sp_stats.sockets_queued,
1227 pool->sp_stats.threads_woken,
1228 pool->sp_stats.threads_timedout);
1229
1230 return 0;
1231}
1232
1233static const struct seq_operations svc_pool_stats_seq_ops = {
1234 .start = svc_pool_stats_start,
1235 .next = svc_pool_stats_next,
1236 .stop = svc_pool_stats_stop,
1237 .show = svc_pool_stats_show,
1238};
1239
1240int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1241{
1242 int err;
1243
1244 err = seq_open(file, &svc_pool_stats_seq_ops);
1245 if (!err)
1246 ((struct seq_file *) file->private_data)->private = serv;
1247 return err;
1248}
1249EXPORT_SYMBOL(svc_pool_stats_open);
1250
1251/*----------------------------------------------------------------------------*/