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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/sched/mm.h>
10#include <linux/errno.h>
11#include <linux/freezer.h>
12#include <linux/kthread.h>
13#include <linux/slab.h>
14#include <net/sock.h>
15#include <linux/sunrpc/addr.h>
16#include <linux/sunrpc/stats.h>
17#include <linux/sunrpc/svc_xprt.h>
18#include <linux/sunrpc/svcsock.h>
19#include <linux/sunrpc/xprt.h>
20#include <linux/module.h>
21#include <linux/netdevice.h>
22#include <trace/events/sunrpc.h>
23
24#define RPCDBG_FACILITY RPCDBG_SVCXPRT
25
26static unsigned int svc_rpc_per_connection_limit __read_mostly;
27module_param(svc_rpc_per_connection_limit, uint, 0644);
28
29
30static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
31static int svc_deferred_recv(struct svc_rqst *rqstp);
32static struct cache_deferred_req *svc_defer(struct cache_req *req);
33static void svc_age_temp_xprts(struct timer_list *t);
34static void svc_delete_xprt(struct svc_xprt *xprt);
35
36/* apparently the "standard" is that clients close
37 * idle connections after 5 minutes, servers after
38 * 6 minutes
39 * http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf
40 */
41static int svc_conn_age_period = 6*60;
42
43/* List of registered transport classes */
44static DEFINE_SPINLOCK(svc_xprt_class_lock);
45static LIST_HEAD(svc_xprt_class_list);
46
47/* SMP locking strategy:
48 *
49 * svc_pool->sp_lock protects most of the fields of that pool.
50 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
51 * when both need to be taken (rare), svc_serv->sv_lock is first.
52 * The "service mutex" protects svc_serv->sv_nrthread.
53 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
54 * and the ->sk_info_authunix cache.
55 *
56 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
57 * enqueued multiply. During normal transport processing this bit
58 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
59 * Providers should not manipulate this bit directly.
60 *
61 * Some flags can be set to certain values at any time
62 * providing that certain rules are followed:
63 *
64 * XPT_CONN, XPT_DATA:
65 * - Can be set or cleared at any time.
66 * - After a set, svc_xprt_enqueue must be called to enqueue
67 * the transport for processing.
68 * - After a clear, the transport must be read/accepted.
69 * If this succeeds, it must be set again.
70 * XPT_CLOSE:
71 * - Can set at any time. It is never cleared.
72 * XPT_DEAD:
73 * - Can only be set while XPT_BUSY is held which ensures
74 * that no other thread will be using the transport or will
75 * try to set XPT_DEAD.
76 */
77int svc_reg_xprt_class(struct svc_xprt_class *xcl)
78{
79 struct svc_xprt_class *cl;
80 int res = -EEXIST;
81
82 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
83
84 INIT_LIST_HEAD(&xcl->xcl_list);
85 spin_lock(&svc_xprt_class_lock);
86 /* Make sure there isn't already a class with the same name */
87 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
88 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
89 goto out;
90 }
91 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
92 res = 0;
93out:
94 spin_unlock(&svc_xprt_class_lock);
95 return res;
96}
97EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
98
99void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
100{
101 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
102 spin_lock(&svc_xprt_class_lock);
103 list_del_init(&xcl->xcl_list);
104 spin_unlock(&svc_xprt_class_lock);
105}
106EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
107
108/**
109 * svc_print_xprts - Format the transport list for printing
110 * @buf: target buffer for formatted address
111 * @maxlen: length of target buffer
112 *
113 * Fills in @buf with a string containing a list of transport names, each name
114 * terminated with '\n'. If the buffer is too small, some entries may be
115 * missing, but it is guaranteed that all lines in the output buffer are
116 * complete.
117 *
118 * Returns positive length of the filled-in string.
119 */
120int svc_print_xprts(char *buf, int maxlen)
121{
122 struct svc_xprt_class *xcl;
123 char tmpstr[80];
124 int len = 0;
125 buf[0] = '\0';
126
127 spin_lock(&svc_xprt_class_lock);
128 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
129 int slen;
130
131 slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n",
132 xcl->xcl_name, xcl->xcl_max_payload);
133 if (slen >= sizeof(tmpstr) || len + slen >= maxlen)
134 break;
135 len += slen;
136 strcat(buf, tmpstr);
137 }
138 spin_unlock(&svc_xprt_class_lock);
139
140 return len;
141}
142
143/**
144 * svc_xprt_deferred_close - Close a transport
145 * @xprt: transport instance
146 *
147 * Used in contexts that need to defer the work of shutting down
148 * the transport to an nfsd thread.
149 */
150void svc_xprt_deferred_close(struct svc_xprt *xprt)
151{
152 if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags))
153 svc_xprt_enqueue(xprt);
154}
155EXPORT_SYMBOL_GPL(svc_xprt_deferred_close);
156
157static void svc_xprt_free(struct kref *kref)
158{
159 struct svc_xprt *xprt =
160 container_of(kref, struct svc_xprt, xpt_ref);
161 struct module *owner = xprt->xpt_class->xcl_owner;
162 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
163 svcauth_unix_info_release(xprt);
164 put_cred(xprt->xpt_cred);
165 put_net_track(xprt->xpt_net, &xprt->ns_tracker);
166 /* See comment on corresponding get in xs_setup_bc_tcp(): */
167 if (xprt->xpt_bc_xprt)
168 xprt_put(xprt->xpt_bc_xprt);
169 if (xprt->xpt_bc_xps)
170 xprt_switch_put(xprt->xpt_bc_xps);
171 trace_svc_xprt_free(xprt);
172 xprt->xpt_ops->xpo_free(xprt);
173 module_put(owner);
174}
175
176void svc_xprt_put(struct svc_xprt *xprt)
177{
178 kref_put(&xprt->xpt_ref, svc_xprt_free);
179}
180EXPORT_SYMBOL_GPL(svc_xprt_put);
181
182/*
183 * Called by transport drivers to initialize the transport independent
184 * portion of the transport instance.
185 */
186void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
187 struct svc_xprt *xprt, struct svc_serv *serv)
188{
189 memset(xprt, 0, sizeof(*xprt));
190 xprt->xpt_class = xcl;
191 xprt->xpt_ops = xcl->xcl_ops;
192 kref_init(&xprt->xpt_ref);
193 xprt->xpt_server = serv;
194 INIT_LIST_HEAD(&xprt->xpt_list);
195 INIT_LIST_HEAD(&xprt->xpt_ready);
196 INIT_LIST_HEAD(&xprt->xpt_deferred);
197 INIT_LIST_HEAD(&xprt->xpt_users);
198 mutex_init(&xprt->xpt_mutex);
199 spin_lock_init(&xprt->xpt_lock);
200 set_bit(XPT_BUSY, &xprt->xpt_flags);
201 xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC);
202 strcpy(xprt->xpt_remotebuf, "uninitialized");
203}
204EXPORT_SYMBOL_GPL(svc_xprt_init);
205
206static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
207 struct svc_serv *serv,
208 struct net *net,
209 const int family,
210 const unsigned short port,
211 int flags)
212{
213 struct sockaddr_in sin = {
214 .sin_family = AF_INET,
215 .sin_addr.s_addr = htonl(INADDR_ANY),
216 .sin_port = htons(port),
217 };
218#if IS_ENABLED(CONFIG_IPV6)
219 struct sockaddr_in6 sin6 = {
220 .sin6_family = AF_INET6,
221 .sin6_addr = IN6ADDR_ANY_INIT,
222 .sin6_port = htons(port),
223 };
224#endif
225 struct svc_xprt *xprt;
226 struct sockaddr *sap;
227 size_t len;
228
229 switch (family) {
230 case PF_INET:
231 sap = (struct sockaddr *)&sin;
232 len = sizeof(sin);
233 break;
234#if IS_ENABLED(CONFIG_IPV6)
235 case PF_INET6:
236 sap = (struct sockaddr *)&sin6;
237 len = sizeof(sin6);
238 break;
239#endif
240 default:
241 return ERR_PTR(-EAFNOSUPPORT);
242 }
243
244 xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
245 if (IS_ERR(xprt))
246 trace_svc_xprt_create_err(serv->sv_program->pg_name,
247 xcl->xcl_name, sap, len, xprt);
248 return xprt;
249}
250
251/**
252 * svc_xprt_received - start next receiver thread
253 * @xprt: controlling transport
254 *
255 * The caller must hold the XPT_BUSY bit and must
256 * not thereafter touch transport data.
257 *
258 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
259 * insufficient) data.
260 */
261void svc_xprt_received(struct svc_xprt *xprt)
262{
263 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) {
264 WARN_ONCE(1, "xprt=0x%p already busy!", xprt);
265 return;
266 }
267
268 /* As soon as we clear busy, the xprt could be closed and
269 * 'put', so we need a reference to call svc_xprt_enqueue with:
270 */
271 svc_xprt_get(xprt);
272 smp_mb__before_atomic();
273 clear_bit(XPT_BUSY, &xprt->xpt_flags);
274 svc_xprt_enqueue(xprt);
275 svc_xprt_put(xprt);
276}
277EXPORT_SYMBOL_GPL(svc_xprt_received);
278
279void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new)
280{
281 clear_bit(XPT_TEMP, &new->xpt_flags);
282 spin_lock_bh(&serv->sv_lock);
283 list_add(&new->xpt_list, &serv->sv_permsocks);
284 spin_unlock_bh(&serv->sv_lock);
285 svc_xprt_received(new);
286}
287
288static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
289 struct net *net, const int family,
290 const unsigned short port, int flags,
291 const struct cred *cred)
292{
293 struct svc_xprt_class *xcl;
294
295 spin_lock(&svc_xprt_class_lock);
296 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
297 struct svc_xprt *newxprt;
298 unsigned short newport;
299
300 if (strcmp(xprt_name, xcl->xcl_name))
301 continue;
302
303 if (!try_module_get(xcl->xcl_owner))
304 goto err;
305
306 spin_unlock(&svc_xprt_class_lock);
307 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
308 if (IS_ERR(newxprt)) {
309 module_put(xcl->xcl_owner);
310 return PTR_ERR(newxprt);
311 }
312 newxprt->xpt_cred = get_cred(cred);
313 svc_add_new_perm_xprt(serv, newxprt);
314 newport = svc_xprt_local_port(newxprt);
315 return newport;
316 }
317 err:
318 spin_unlock(&svc_xprt_class_lock);
319 /* This errno is exposed to user space. Provide a reasonable
320 * perror msg for a bad transport. */
321 return -EPROTONOSUPPORT;
322}
323
324/**
325 * svc_xprt_create - Add a new listener to @serv
326 * @serv: target RPC service
327 * @xprt_name: transport class name
328 * @net: network namespace
329 * @family: network address family
330 * @port: listener port
331 * @flags: SVC_SOCK flags
332 * @cred: credential to bind to this transport
333 *
334 * Return values:
335 * %0: New listener added successfully
336 * %-EPROTONOSUPPORT: Requested transport type not supported
337 */
338int svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
339 struct net *net, const int family,
340 const unsigned short port, int flags,
341 const struct cred *cred)
342{
343 int err;
344
345 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred);
346 if (err == -EPROTONOSUPPORT) {
347 request_module("svc%s", xprt_name);
348 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred);
349 }
350 return err;
351}
352EXPORT_SYMBOL_GPL(svc_xprt_create);
353
354/*
355 * Copy the local and remote xprt addresses to the rqstp structure
356 */
357void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
358{
359 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
360 rqstp->rq_addrlen = xprt->xpt_remotelen;
361
362 /*
363 * Destination address in request is needed for binding the
364 * source address in RPC replies/callbacks later.
365 */
366 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen);
367 rqstp->rq_daddrlen = xprt->xpt_locallen;
368}
369EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
370
371/**
372 * svc_print_addr - Format rq_addr field for printing
373 * @rqstp: svc_rqst struct containing address to print
374 * @buf: target buffer for formatted address
375 * @len: length of target buffer
376 *
377 */
378char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
379{
380 return __svc_print_addr(svc_addr(rqstp), buf, len);
381}
382EXPORT_SYMBOL_GPL(svc_print_addr);
383
384static bool svc_xprt_slots_in_range(struct svc_xprt *xprt)
385{
386 unsigned int limit = svc_rpc_per_connection_limit;
387 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts);
388
389 return limit == 0 || (nrqsts >= 0 && nrqsts < limit);
390}
391
392static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt)
393{
394 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) {
395 if (!svc_xprt_slots_in_range(xprt))
396 return false;
397 atomic_inc(&xprt->xpt_nr_rqsts);
398 set_bit(RQ_DATA, &rqstp->rq_flags);
399 }
400 return true;
401}
402
403static void svc_xprt_release_slot(struct svc_rqst *rqstp)
404{
405 struct svc_xprt *xprt = rqstp->rq_xprt;
406 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) {
407 atomic_dec(&xprt->xpt_nr_rqsts);
408 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
409 svc_xprt_enqueue(xprt);
410 }
411}
412
413static bool svc_xprt_ready(struct svc_xprt *xprt)
414{
415 unsigned long xpt_flags;
416
417 /*
418 * If another cpu has recently updated xpt_flags,
419 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to
420 * know about it; otherwise it's possible that both that cpu and
421 * this one could call svc_xprt_enqueue() without either
422 * svc_xprt_enqueue() recognizing that the conditions below
423 * are satisfied, and we could stall indefinitely:
424 */
425 smp_rmb();
426 xpt_flags = READ_ONCE(xprt->xpt_flags);
427
428 if (xpt_flags & BIT(XPT_BUSY))
429 return false;
430 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE)))
431 return true;
432 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) {
433 if (xprt->xpt_ops->xpo_has_wspace(xprt) &&
434 svc_xprt_slots_in_range(xprt))
435 return true;
436 trace_svc_xprt_no_write_space(xprt);
437 return false;
438 }
439 return false;
440}
441
442/**
443 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread
444 * @xprt: transport with data pending
445 *
446 */
447void svc_xprt_enqueue(struct svc_xprt *xprt)
448{
449 struct svc_pool *pool;
450 struct svc_rqst *rqstp = NULL;
451
452 if (!svc_xprt_ready(xprt))
453 return;
454
455 /* Mark transport as busy. It will remain in this state until
456 * the provider calls svc_xprt_received. We update XPT_BUSY
457 * atomically because it also guards against trying to enqueue
458 * the transport twice.
459 */
460 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
461 return;
462
463 pool = svc_pool_for_cpu(xprt->xpt_server);
464
465 atomic_long_inc(&pool->sp_stats.packets);
466
467 spin_lock_bh(&pool->sp_lock);
468 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
469 pool->sp_stats.sockets_queued++;
470 spin_unlock_bh(&pool->sp_lock);
471
472 /* find a thread for this xprt */
473 rcu_read_lock();
474 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
475 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags))
476 continue;
477 atomic_long_inc(&pool->sp_stats.threads_woken);
478 rqstp->rq_qtime = ktime_get();
479 wake_up_process(rqstp->rq_task);
480 goto out_unlock;
481 }
482 set_bit(SP_CONGESTED, &pool->sp_flags);
483 rqstp = NULL;
484out_unlock:
485 rcu_read_unlock();
486 trace_svc_xprt_enqueue(xprt, rqstp);
487}
488EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
489
490/*
491 * Dequeue the first transport, if there is one.
492 */
493static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
494{
495 struct svc_xprt *xprt = NULL;
496
497 if (list_empty(&pool->sp_sockets))
498 goto out;
499
500 spin_lock_bh(&pool->sp_lock);
501 if (likely(!list_empty(&pool->sp_sockets))) {
502 xprt = list_first_entry(&pool->sp_sockets,
503 struct svc_xprt, xpt_ready);
504 list_del_init(&xprt->xpt_ready);
505 svc_xprt_get(xprt);
506 }
507 spin_unlock_bh(&pool->sp_lock);
508out:
509 return xprt;
510}
511
512/**
513 * svc_reserve - change the space reserved for the reply to a request.
514 * @rqstp: The request in question
515 * @space: new max space to reserve
516 *
517 * Each request reserves some space on the output queue of the transport
518 * to make sure the reply fits. This function reduces that reserved
519 * space to be the amount of space used already, plus @space.
520 *
521 */
522void svc_reserve(struct svc_rqst *rqstp, int space)
523{
524 struct svc_xprt *xprt = rqstp->rq_xprt;
525
526 space += rqstp->rq_res.head[0].iov_len;
527
528 if (xprt && space < rqstp->rq_reserved) {
529 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
530 rqstp->rq_reserved = space;
531 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
532 svc_xprt_enqueue(xprt);
533 }
534}
535EXPORT_SYMBOL_GPL(svc_reserve);
536
537static void svc_xprt_release(struct svc_rqst *rqstp)
538{
539 struct svc_xprt *xprt = rqstp->rq_xprt;
540
541 xprt->xpt_ops->xpo_release_rqst(rqstp);
542
543 kfree(rqstp->rq_deferred);
544 rqstp->rq_deferred = NULL;
545
546 pagevec_release(&rqstp->rq_pvec);
547 svc_free_res_pages(rqstp);
548 rqstp->rq_res.page_len = 0;
549 rqstp->rq_res.page_base = 0;
550
551 /* Reset response buffer and release
552 * the reservation.
553 * But first, check that enough space was reserved
554 * for the reply, otherwise we have a bug!
555 */
556 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
557 printk(KERN_ERR "RPC request reserved %d but used %d\n",
558 rqstp->rq_reserved,
559 rqstp->rq_res.len);
560
561 rqstp->rq_res.head[0].iov_len = 0;
562 svc_reserve(rqstp, 0);
563 svc_xprt_release_slot(rqstp);
564 rqstp->rq_xprt = NULL;
565 svc_xprt_put(xprt);
566}
567
568/*
569 * Some svc_serv's will have occasional work to do, even when a xprt is not
570 * waiting to be serviced. This function is there to "kick" a task in one of
571 * those services so that it can wake up and do that work. Note that we only
572 * bother with pool 0 as we don't need to wake up more than one thread for
573 * this purpose.
574 */
575void svc_wake_up(struct svc_serv *serv)
576{
577 struct svc_rqst *rqstp;
578 struct svc_pool *pool;
579
580 pool = &serv->sv_pools[0];
581
582 rcu_read_lock();
583 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) {
584 /* skip any that aren't queued */
585 if (test_bit(RQ_BUSY, &rqstp->rq_flags))
586 continue;
587 rcu_read_unlock();
588 wake_up_process(rqstp->rq_task);
589 trace_svc_wake_up(rqstp->rq_task->pid);
590 return;
591 }
592 rcu_read_unlock();
593
594 /* No free entries available */
595 set_bit(SP_TASK_PENDING, &pool->sp_flags);
596 smp_wmb();
597 trace_svc_wake_up(0);
598}
599EXPORT_SYMBOL_GPL(svc_wake_up);
600
601int svc_port_is_privileged(struct sockaddr *sin)
602{
603 switch (sin->sa_family) {
604 case AF_INET:
605 return ntohs(((struct sockaddr_in *)sin)->sin_port)
606 < PROT_SOCK;
607 case AF_INET6:
608 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
609 < PROT_SOCK;
610 default:
611 return 0;
612 }
613}
614
615/*
616 * Make sure that we don't have too many active connections. If we have,
617 * something must be dropped. It's not clear what will happen if we allow
618 * "too many" connections, but when dealing with network-facing software,
619 * we have to code defensively. Here we do that by imposing hard limits.
620 *
621 * There's no point in trying to do random drop here for DoS
622 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
623 * attacker can easily beat that.
624 *
625 * The only somewhat efficient mechanism would be if drop old
626 * connections from the same IP first. But right now we don't even
627 * record the client IP in svc_sock.
628 *
629 * single-threaded services that expect a lot of clients will probably
630 * need to set sv_maxconn to override the default value which is based
631 * on the number of threads
632 */
633static void svc_check_conn_limits(struct svc_serv *serv)
634{
635 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
636 (serv->sv_nrthreads+3) * 20;
637
638 if (serv->sv_tmpcnt > limit) {
639 struct svc_xprt *xprt = NULL;
640 spin_lock_bh(&serv->sv_lock);
641 if (!list_empty(&serv->sv_tempsocks)) {
642 /* Try to help the admin */
643 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
644 serv->sv_name, serv->sv_maxconn ?
645 "max number of connections" :
646 "number of threads");
647 /*
648 * Always select the oldest connection. It's not fair,
649 * but so is life
650 */
651 xprt = list_entry(serv->sv_tempsocks.prev,
652 struct svc_xprt,
653 xpt_list);
654 set_bit(XPT_CLOSE, &xprt->xpt_flags);
655 svc_xprt_get(xprt);
656 }
657 spin_unlock_bh(&serv->sv_lock);
658
659 if (xprt) {
660 svc_xprt_enqueue(xprt);
661 svc_xprt_put(xprt);
662 }
663 }
664}
665
666static int svc_alloc_arg(struct svc_rqst *rqstp)
667{
668 struct svc_serv *serv = rqstp->rq_server;
669 struct xdr_buf *arg = &rqstp->rq_arg;
670 unsigned long pages, filled, ret;
671
672 pagevec_init(&rqstp->rq_pvec);
673
674 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT;
675 if (pages > RPCSVC_MAXPAGES) {
676 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n",
677 pages, RPCSVC_MAXPAGES);
678 /* use as many pages as possible */
679 pages = RPCSVC_MAXPAGES;
680 }
681
682 for (filled = 0; filled < pages; filled = ret) {
683 ret = alloc_pages_bulk_array(GFP_KERNEL, pages,
684 rqstp->rq_pages);
685 if (ret > filled)
686 /* Made progress, don't sleep yet */
687 continue;
688
689 set_current_state(TASK_INTERRUPTIBLE);
690 if (signalled() || kthread_should_stop()) {
691 set_current_state(TASK_RUNNING);
692 return -EINTR;
693 }
694 trace_svc_alloc_arg_err(pages, ret);
695 memalloc_retry_wait(GFP_KERNEL);
696 }
697 rqstp->rq_page_end = &rqstp->rq_pages[pages];
698 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */
699
700 /* Make arg->head point to first page and arg->pages point to rest */
701 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
702 arg->head[0].iov_len = PAGE_SIZE;
703 arg->pages = rqstp->rq_pages + 1;
704 arg->page_base = 0;
705 /* save at least one page for response */
706 arg->page_len = (pages-2)*PAGE_SIZE;
707 arg->len = (pages-1)*PAGE_SIZE;
708 arg->tail[0].iov_len = 0;
709 return 0;
710}
711
712static bool
713rqst_should_sleep(struct svc_rqst *rqstp)
714{
715 struct svc_pool *pool = rqstp->rq_pool;
716
717 /* did someone call svc_wake_up? */
718 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags))
719 return false;
720
721 /* was a socket queued? */
722 if (!list_empty(&pool->sp_sockets))
723 return false;
724
725 /* are we shutting down? */
726 if (signalled() || kthread_should_stop())
727 return false;
728
729 /* are we freezing? */
730 if (freezing(current))
731 return false;
732
733 return true;
734}
735
736static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
737{
738 struct svc_pool *pool = rqstp->rq_pool;
739 long time_left = 0;
740
741 /* rq_xprt should be clear on entry */
742 WARN_ON_ONCE(rqstp->rq_xprt);
743
744 rqstp->rq_xprt = svc_xprt_dequeue(pool);
745 if (rqstp->rq_xprt)
746 goto out_found;
747
748 /*
749 * We have to be able to interrupt this wait
750 * to bring down the daemons ...
751 */
752 set_current_state(TASK_INTERRUPTIBLE);
753 smp_mb__before_atomic();
754 clear_bit(SP_CONGESTED, &pool->sp_flags);
755 clear_bit(RQ_BUSY, &rqstp->rq_flags);
756 smp_mb__after_atomic();
757
758 if (likely(rqst_should_sleep(rqstp)))
759 time_left = schedule_timeout(timeout);
760 else
761 __set_current_state(TASK_RUNNING);
762
763 try_to_freeze();
764
765 set_bit(RQ_BUSY, &rqstp->rq_flags);
766 smp_mb__after_atomic();
767 rqstp->rq_xprt = svc_xprt_dequeue(pool);
768 if (rqstp->rq_xprt)
769 goto out_found;
770
771 if (!time_left)
772 atomic_long_inc(&pool->sp_stats.threads_timedout);
773
774 if (signalled() || kthread_should_stop())
775 return ERR_PTR(-EINTR);
776 return ERR_PTR(-EAGAIN);
777out_found:
778 /* Normally we will wait up to 5 seconds for any required
779 * cache information to be provided.
780 */
781 if (!test_bit(SP_CONGESTED, &pool->sp_flags))
782 rqstp->rq_chandle.thread_wait = 5*HZ;
783 else
784 rqstp->rq_chandle.thread_wait = 1*HZ;
785 trace_svc_xprt_dequeue(rqstp);
786 return rqstp->rq_xprt;
787}
788
789static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt)
790{
791 spin_lock_bh(&serv->sv_lock);
792 set_bit(XPT_TEMP, &newxpt->xpt_flags);
793 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
794 serv->sv_tmpcnt++;
795 if (serv->sv_temptimer.function == NULL) {
796 /* setup timer to age temp transports */
797 serv->sv_temptimer.function = svc_age_temp_xprts;
798 mod_timer(&serv->sv_temptimer,
799 jiffies + svc_conn_age_period * HZ);
800 }
801 spin_unlock_bh(&serv->sv_lock);
802 svc_xprt_received(newxpt);
803}
804
805static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
806{
807 struct svc_serv *serv = rqstp->rq_server;
808 int len = 0;
809
810 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
811 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags))
812 xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
813 svc_delete_xprt(xprt);
814 /* Leave XPT_BUSY set on the dead xprt: */
815 goto out;
816 }
817 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
818 struct svc_xprt *newxpt;
819 /*
820 * We know this module_get will succeed because the
821 * listener holds a reference too
822 */
823 __module_get(xprt->xpt_class->xcl_owner);
824 svc_check_conn_limits(xprt->xpt_server);
825 newxpt = xprt->xpt_ops->xpo_accept(xprt);
826 if (newxpt) {
827 newxpt->xpt_cred = get_cred(xprt->xpt_cred);
828 svc_add_new_temp_xprt(serv, newxpt);
829 trace_svc_xprt_accept(newxpt, serv->sv_name);
830 } else {
831 module_put(xprt->xpt_class->xcl_owner);
832 }
833 svc_xprt_received(xprt);
834 } else if (svc_xprt_reserve_slot(rqstp, xprt)) {
835 /* XPT_DATA|XPT_DEFERRED case: */
836 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
837 rqstp, rqstp->rq_pool->sp_id, xprt,
838 kref_read(&xprt->xpt_ref));
839 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
840 if (rqstp->rq_deferred)
841 len = svc_deferred_recv(rqstp);
842 else
843 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
844 rqstp->rq_stime = ktime_get();
845 rqstp->rq_reserved = serv->sv_max_mesg;
846 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
847 } else
848 svc_xprt_received(xprt);
849
850out:
851 return len;
852}
853
854/*
855 * Receive the next request on any transport. This code is carefully
856 * organised not to touch any cachelines in the shared svc_serv
857 * structure, only cachelines in the local svc_pool.
858 */
859int svc_recv(struct svc_rqst *rqstp, long timeout)
860{
861 struct svc_xprt *xprt = NULL;
862 struct svc_serv *serv = rqstp->rq_server;
863 int len, err;
864
865 err = svc_alloc_arg(rqstp);
866 if (err)
867 goto out;
868
869 try_to_freeze();
870 cond_resched();
871 err = -EINTR;
872 if (signalled() || kthread_should_stop())
873 goto out;
874
875 xprt = svc_get_next_xprt(rqstp, timeout);
876 if (IS_ERR(xprt)) {
877 err = PTR_ERR(xprt);
878 goto out;
879 }
880
881 len = svc_handle_xprt(rqstp, xprt);
882
883 /* No data, incomplete (TCP) read, or accept() */
884 err = -EAGAIN;
885 if (len <= 0)
886 goto out_release;
887 trace_svc_xdr_recvfrom(&rqstp->rq_arg);
888
889 clear_bit(XPT_OLD, &xprt->xpt_flags);
890
891 xprt->xpt_ops->xpo_secure_port(rqstp);
892 rqstp->rq_chandle.defer = svc_defer;
893 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]);
894
895 if (serv->sv_stats)
896 serv->sv_stats->netcnt++;
897 return len;
898out_release:
899 rqstp->rq_res.len = 0;
900 svc_xprt_release(rqstp);
901out:
902 return err;
903}
904EXPORT_SYMBOL_GPL(svc_recv);
905
906/*
907 * Drop request
908 */
909void svc_drop(struct svc_rqst *rqstp)
910{
911 trace_svc_drop(rqstp);
912 svc_xprt_release(rqstp);
913}
914EXPORT_SYMBOL_GPL(svc_drop);
915
916/*
917 * Return reply to client.
918 */
919int svc_send(struct svc_rqst *rqstp)
920{
921 struct svc_xprt *xprt;
922 int len = -EFAULT;
923 struct xdr_buf *xb;
924
925 xprt = rqstp->rq_xprt;
926 if (!xprt)
927 goto out;
928
929 /* calculate over-all length */
930 xb = &rqstp->rq_res;
931 xb->len = xb->head[0].iov_len +
932 xb->page_len +
933 xb->tail[0].iov_len;
934 trace_svc_xdr_sendto(rqstp->rq_xid, xb);
935 trace_svc_stats_latency(rqstp);
936
937 len = xprt->xpt_ops->xpo_sendto(rqstp);
938
939 trace_svc_send(rqstp, len);
940 svc_xprt_release(rqstp);
941
942 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
943 len = 0;
944out:
945 return len;
946}
947
948/*
949 * Timer function to close old temporary transports, using
950 * a mark-and-sweep algorithm.
951 */
952static void svc_age_temp_xprts(struct timer_list *t)
953{
954 struct svc_serv *serv = from_timer(serv, t, sv_temptimer);
955 struct svc_xprt *xprt;
956 struct list_head *le, *next;
957
958 dprintk("svc_age_temp_xprts\n");
959
960 if (!spin_trylock_bh(&serv->sv_lock)) {
961 /* busy, try again 1 sec later */
962 dprintk("svc_age_temp_xprts: busy\n");
963 mod_timer(&serv->sv_temptimer, jiffies + HZ);
964 return;
965 }
966
967 list_for_each_safe(le, next, &serv->sv_tempsocks) {
968 xprt = list_entry(le, struct svc_xprt, xpt_list);
969
970 /* First time through, just mark it OLD. Second time
971 * through, close it. */
972 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
973 continue;
974 if (kref_read(&xprt->xpt_ref) > 1 ||
975 test_bit(XPT_BUSY, &xprt->xpt_flags))
976 continue;
977 list_del_init(le);
978 set_bit(XPT_CLOSE, &xprt->xpt_flags);
979 dprintk("queuing xprt %p for closing\n", xprt);
980
981 /* a thread will dequeue and close it soon */
982 svc_xprt_enqueue(xprt);
983 }
984 spin_unlock_bh(&serv->sv_lock);
985
986 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
987}
988
989/* Close temporary transports whose xpt_local matches server_addr immediately
990 * instead of waiting for them to be picked up by the timer.
991 *
992 * This is meant to be called from a notifier_block that runs when an ip
993 * address is deleted.
994 */
995void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr)
996{
997 struct svc_xprt *xprt;
998 struct list_head *le, *next;
999 LIST_HEAD(to_be_closed);
1000
1001 spin_lock_bh(&serv->sv_lock);
1002 list_for_each_safe(le, next, &serv->sv_tempsocks) {
1003 xprt = list_entry(le, struct svc_xprt, xpt_list);
1004 if (rpc_cmp_addr(server_addr, (struct sockaddr *)
1005 &xprt->xpt_local)) {
1006 dprintk("svc_age_temp_xprts_now: found %p\n", xprt);
1007 list_move(le, &to_be_closed);
1008 }
1009 }
1010 spin_unlock_bh(&serv->sv_lock);
1011
1012 while (!list_empty(&to_be_closed)) {
1013 le = to_be_closed.next;
1014 list_del_init(le);
1015 xprt = list_entry(le, struct svc_xprt, xpt_list);
1016 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1017 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags);
1018 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
1019 xprt);
1020 svc_xprt_enqueue(xprt);
1021 }
1022}
1023EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);
1024
1025static void call_xpt_users(struct svc_xprt *xprt)
1026{
1027 struct svc_xpt_user *u;
1028
1029 spin_lock(&xprt->xpt_lock);
1030 while (!list_empty(&xprt->xpt_users)) {
1031 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
1032 list_del_init(&u->list);
1033 u->callback(u);
1034 }
1035 spin_unlock(&xprt->xpt_lock);
1036}
1037
1038/*
1039 * Remove a dead transport
1040 */
1041static void svc_delete_xprt(struct svc_xprt *xprt)
1042{
1043 struct svc_serv *serv = xprt->xpt_server;
1044 struct svc_deferred_req *dr;
1045
1046 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
1047 return;
1048
1049 trace_svc_xprt_detach(xprt);
1050 xprt->xpt_ops->xpo_detach(xprt);
1051 if (xprt->xpt_bc_xprt)
1052 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt);
1053
1054 spin_lock_bh(&serv->sv_lock);
1055 list_del_init(&xprt->xpt_list);
1056 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready));
1057 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
1058 serv->sv_tmpcnt--;
1059 spin_unlock_bh(&serv->sv_lock);
1060
1061 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
1062 kfree(dr);
1063
1064 call_xpt_users(xprt);
1065 svc_xprt_put(xprt);
1066}
1067
1068/**
1069 * svc_xprt_close - Close a client connection
1070 * @xprt: transport to disconnect
1071 *
1072 */
1073void svc_xprt_close(struct svc_xprt *xprt)
1074{
1075 trace_svc_xprt_close(xprt);
1076 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1077 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
1078 /* someone else will have to effect the close */
1079 return;
1080 /*
1081 * We expect svc_close_xprt() to work even when no threads are
1082 * running (e.g., while configuring the server before starting
1083 * any threads), so if the transport isn't busy, we delete
1084 * it ourself:
1085 */
1086 svc_delete_xprt(xprt);
1087}
1088EXPORT_SYMBOL_GPL(svc_xprt_close);
1089
1090static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net)
1091{
1092 struct svc_xprt *xprt;
1093 int ret = 0;
1094
1095 spin_lock_bh(&serv->sv_lock);
1096 list_for_each_entry(xprt, xprt_list, xpt_list) {
1097 if (xprt->xpt_net != net)
1098 continue;
1099 ret++;
1100 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1101 svc_xprt_enqueue(xprt);
1102 }
1103 spin_unlock_bh(&serv->sv_lock);
1104 return ret;
1105}
1106
1107static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net)
1108{
1109 struct svc_pool *pool;
1110 struct svc_xprt *xprt;
1111 struct svc_xprt *tmp;
1112 int i;
1113
1114 for (i = 0; i < serv->sv_nrpools; i++) {
1115 pool = &serv->sv_pools[i];
1116
1117 spin_lock_bh(&pool->sp_lock);
1118 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) {
1119 if (xprt->xpt_net != net)
1120 continue;
1121 list_del_init(&xprt->xpt_ready);
1122 spin_unlock_bh(&pool->sp_lock);
1123 return xprt;
1124 }
1125 spin_unlock_bh(&pool->sp_lock);
1126 }
1127 return NULL;
1128}
1129
1130static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
1131{
1132 struct svc_xprt *xprt;
1133
1134 while ((xprt = svc_dequeue_net(serv, net))) {
1135 set_bit(XPT_CLOSE, &xprt->xpt_flags);
1136 svc_delete_xprt(xprt);
1137 }
1138}
1139
1140/**
1141 * svc_xprt_destroy_all - Destroy transports associated with @serv
1142 * @serv: RPC service to be shut down
1143 * @net: target network namespace
1144 *
1145 * Server threads may still be running (especially in the case where the
1146 * service is still running in other network namespaces).
1147 *
1148 * So we shut down sockets the same way we would on a running server, by
1149 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do
1150 * the close. In the case there are no such other threads,
1151 * threads running, svc_clean_up_xprts() does a simple version of a
1152 * server's main event loop, and in the case where there are other
1153 * threads, we may need to wait a little while and then check again to
1154 * see if they're done.
1155 */
1156void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net)
1157{
1158 int delay = 0;
1159
1160 while (svc_close_list(serv, &serv->sv_permsocks, net) +
1161 svc_close_list(serv, &serv->sv_tempsocks, net)) {
1162
1163 svc_clean_up_xprts(serv, net);
1164 msleep(delay++);
1165 }
1166}
1167EXPORT_SYMBOL_GPL(svc_xprt_destroy_all);
1168
1169/*
1170 * Handle defer and revisit of requests
1171 */
1172
1173static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
1174{
1175 struct svc_deferred_req *dr =
1176 container_of(dreq, struct svc_deferred_req, handle);
1177 struct svc_xprt *xprt = dr->xprt;
1178
1179 spin_lock(&xprt->xpt_lock);
1180 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
1181 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
1182 spin_unlock(&xprt->xpt_lock);
1183 trace_svc_defer_drop(dr);
1184 svc_xprt_put(xprt);
1185 kfree(dr);
1186 return;
1187 }
1188 dr->xprt = NULL;
1189 list_add(&dr->handle.recent, &xprt->xpt_deferred);
1190 spin_unlock(&xprt->xpt_lock);
1191 trace_svc_defer_queue(dr);
1192 svc_xprt_enqueue(xprt);
1193 svc_xprt_put(xprt);
1194}
1195
1196/*
1197 * Save the request off for later processing. The request buffer looks
1198 * like this:
1199 *
1200 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1201 *
1202 * This code can only handle requests that consist of an xprt-header
1203 * and rpc-header.
1204 */
1205static struct cache_deferred_req *svc_defer(struct cache_req *req)
1206{
1207 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1208 struct svc_deferred_req *dr;
1209
1210 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags))
1211 return NULL; /* if more than a page, give up FIXME */
1212 if (rqstp->rq_deferred) {
1213 dr = rqstp->rq_deferred;
1214 rqstp->rq_deferred = NULL;
1215 } else {
1216 size_t skip;
1217 size_t size;
1218 /* FIXME maybe discard if size too large */
1219 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
1220 dr = kmalloc(size, GFP_KERNEL);
1221 if (dr == NULL)
1222 return NULL;
1223
1224 dr->handle.owner = rqstp->rq_server;
1225 dr->prot = rqstp->rq_prot;
1226 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1227 dr->addrlen = rqstp->rq_addrlen;
1228 dr->daddr = rqstp->rq_daddr;
1229 dr->argslen = rqstp->rq_arg.len >> 2;
1230 dr->xprt_ctxt = rqstp->rq_xprt_ctxt;
1231 rqstp->rq_xprt_ctxt = NULL;
1232
1233 /* back up head to the start of the buffer and copy */
1234 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1235 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1236 dr->argslen << 2);
1237 }
1238 trace_svc_defer(rqstp);
1239 svc_xprt_get(rqstp->rq_xprt);
1240 dr->xprt = rqstp->rq_xprt;
1241 set_bit(RQ_DROPME, &rqstp->rq_flags);
1242
1243 dr->handle.revisit = svc_revisit;
1244 return &dr->handle;
1245}
1246
1247/*
1248 * recv data from a deferred request into an active one
1249 */
1250static noinline int svc_deferred_recv(struct svc_rqst *rqstp)
1251{
1252 struct svc_deferred_req *dr = rqstp->rq_deferred;
1253
1254 trace_svc_defer_recv(dr);
1255
1256 /* setup iov_base past transport header */
1257 rqstp->rq_arg.head[0].iov_base = dr->args;
1258 /* The iov_len does not include the transport header bytes */
1259 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2;
1260 rqstp->rq_arg.page_len = 0;
1261 /* The rq_arg.len includes the transport header bytes */
1262 rqstp->rq_arg.len = dr->argslen << 2;
1263 rqstp->rq_prot = dr->prot;
1264 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1265 rqstp->rq_addrlen = dr->addrlen;
1266 /* Save off transport header len in case we get deferred again */
1267 rqstp->rq_daddr = dr->daddr;
1268 rqstp->rq_respages = rqstp->rq_pages;
1269 rqstp->rq_xprt_ctxt = dr->xprt_ctxt;
1270 svc_xprt_received(rqstp->rq_xprt);
1271 return dr->argslen << 2;
1272}
1273
1274
1275static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1276{
1277 struct svc_deferred_req *dr = NULL;
1278
1279 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1280 return NULL;
1281 spin_lock(&xprt->xpt_lock);
1282 if (!list_empty(&xprt->xpt_deferred)) {
1283 dr = list_entry(xprt->xpt_deferred.next,
1284 struct svc_deferred_req,
1285 handle.recent);
1286 list_del_init(&dr->handle.recent);
1287 } else
1288 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1289 spin_unlock(&xprt->xpt_lock);
1290 return dr;
1291}
1292
1293/**
1294 * svc_find_xprt - find an RPC transport instance
1295 * @serv: pointer to svc_serv to search
1296 * @xcl_name: C string containing transport's class name
1297 * @net: owner net pointer
1298 * @af: Address family of transport's local address
1299 * @port: transport's IP port number
1300 *
1301 * Return the transport instance pointer for the endpoint accepting
1302 * connections/peer traffic from the specified transport class,
1303 * address family and port.
1304 *
1305 * Specifying 0 for the address family or port is effectively a
1306 * wild-card, and will result in matching the first transport in the
1307 * service's list that has a matching class name.
1308 */
1309struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1310 struct net *net, const sa_family_t af,
1311 const unsigned short port)
1312{
1313 struct svc_xprt *xprt;
1314 struct svc_xprt *found = NULL;
1315
1316 /* Sanity check the args */
1317 if (serv == NULL || xcl_name == NULL)
1318 return found;
1319
1320 spin_lock_bh(&serv->sv_lock);
1321 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1322 if (xprt->xpt_net != net)
1323 continue;
1324 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1325 continue;
1326 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1327 continue;
1328 if (port != 0 && port != svc_xprt_local_port(xprt))
1329 continue;
1330 found = xprt;
1331 svc_xprt_get(xprt);
1332 break;
1333 }
1334 spin_unlock_bh(&serv->sv_lock);
1335 return found;
1336}
1337EXPORT_SYMBOL_GPL(svc_find_xprt);
1338
1339static int svc_one_xprt_name(const struct svc_xprt *xprt,
1340 char *pos, int remaining)
1341{
1342 int len;
1343
1344 len = snprintf(pos, remaining, "%s %u\n",
1345 xprt->xpt_class->xcl_name,
1346 svc_xprt_local_port(xprt));
1347 if (len >= remaining)
1348 return -ENAMETOOLONG;
1349 return len;
1350}
1351
1352/**
1353 * svc_xprt_names - format a buffer with a list of transport names
1354 * @serv: pointer to an RPC service
1355 * @buf: pointer to a buffer to be filled in
1356 * @buflen: length of buffer to be filled in
1357 *
1358 * Fills in @buf with a string containing a list of transport names,
1359 * each name terminated with '\n'.
1360 *
1361 * Returns positive length of the filled-in string on success; otherwise
1362 * a negative errno value is returned if an error occurs.
1363 */
1364int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1365{
1366 struct svc_xprt *xprt;
1367 int len, totlen;
1368 char *pos;
1369
1370 /* Sanity check args */
1371 if (!serv)
1372 return 0;
1373
1374 spin_lock_bh(&serv->sv_lock);
1375
1376 pos = buf;
1377 totlen = 0;
1378 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1379 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1380 if (len < 0) {
1381 *buf = '\0';
1382 totlen = len;
1383 }
1384 if (len <= 0)
1385 break;
1386
1387 pos += len;
1388 totlen += len;
1389 }
1390
1391 spin_unlock_bh(&serv->sv_lock);
1392 return totlen;
1393}
1394EXPORT_SYMBOL_GPL(svc_xprt_names);
1395
1396
1397/*----------------------------------------------------------------------------*/
1398
1399static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1400{
1401 unsigned int pidx = (unsigned int)*pos;
1402 struct svc_serv *serv = m->private;
1403
1404 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1405
1406 if (!pidx)
1407 return SEQ_START_TOKEN;
1408 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1409}
1410
1411static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1412{
1413 struct svc_pool *pool = p;
1414 struct svc_serv *serv = m->private;
1415
1416 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1417
1418 if (p == SEQ_START_TOKEN) {
1419 pool = &serv->sv_pools[0];
1420 } else {
1421 unsigned int pidx = (pool - &serv->sv_pools[0]);
1422 if (pidx < serv->sv_nrpools-1)
1423 pool = &serv->sv_pools[pidx+1];
1424 else
1425 pool = NULL;
1426 }
1427 ++*pos;
1428 return pool;
1429}
1430
1431static void svc_pool_stats_stop(struct seq_file *m, void *p)
1432{
1433}
1434
1435static int svc_pool_stats_show(struct seq_file *m, void *p)
1436{
1437 struct svc_pool *pool = p;
1438
1439 if (p == SEQ_START_TOKEN) {
1440 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1441 return 0;
1442 }
1443
1444 seq_printf(m, "%u %lu %lu %lu %lu\n",
1445 pool->sp_id,
1446 (unsigned long)atomic_long_read(&pool->sp_stats.packets),
1447 pool->sp_stats.sockets_queued,
1448 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken),
1449 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout));
1450
1451 return 0;
1452}
1453
1454static const struct seq_operations svc_pool_stats_seq_ops = {
1455 .start = svc_pool_stats_start,
1456 .next = svc_pool_stats_next,
1457 .stop = svc_pool_stats_stop,
1458 .show = svc_pool_stats_show,
1459};
1460
1461int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1462{
1463 int err;
1464
1465 err = seq_open(file, &svc_pool_stats_seq_ops);
1466 if (!err)
1467 ((struct seq_file *) file->private_data)->private = serv;
1468 return err;
1469}
1470EXPORT_SYMBOL(svc_pool_stats_open);
1471
1472/*----------------------------------------------------------------------------*/
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#include <linux/module.h>
18
19#define RPCDBG_FACILITY RPCDBG_SVCXPRT
20
21static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
22static int svc_deferred_recv(struct svc_rqst *rqstp);
23static struct cache_deferred_req *svc_defer(struct cache_req *req);
24static void svc_age_temp_xprts(unsigned long closure);
25static void svc_delete_xprt(struct svc_xprt *xprt);
26
27/* apparently the "standard" is that clients close
28 * idle connections after 5 minutes, servers after
29 * 6 minutes
30 * http://www.connectathon.org/talks96/nfstcp.pdf
31 */
32static int svc_conn_age_period = 6*60;
33
34/* List of registered transport classes */
35static DEFINE_SPINLOCK(svc_xprt_class_lock);
36static LIST_HEAD(svc_xprt_class_list);
37
38/* SMP locking strategy:
39 *
40 * svc_pool->sp_lock protects most of the fields of that pool.
41 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
42 * when both need to be taken (rare), svc_serv->sv_lock is first.
43 * BKL protects svc_serv->sv_nrthread.
44 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
45 * and the ->sk_info_authunix cache.
46 *
47 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
48 * enqueued multiply. During normal transport processing this bit
49 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
50 * Providers should not manipulate this bit directly.
51 *
52 * Some flags can be set to certain values at any time
53 * providing that certain rules are followed:
54 *
55 * XPT_CONN, XPT_DATA:
56 * - Can be set or cleared at any time.
57 * - After a set, svc_xprt_enqueue must be called to enqueue
58 * the transport for processing.
59 * - After a clear, the transport must be read/accepted.
60 * If this succeeds, it must be set again.
61 * XPT_CLOSE:
62 * - Can set at any time. It is never cleared.
63 * XPT_DEAD:
64 * - Can only be set while XPT_BUSY is held which ensures
65 * that no other thread will be using the transport or will
66 * try to set XPT_DEAD.
67 */
68
69int svc_reg_xprt_class(struct svc_xprt_class *xcl)
70{
71 struct svc_xprt_class *cl;
72 int res = -EEXIST;
73
74 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
75
76 INIT_LIST_HEAD(&xcl->xcl_list);
77 spin_lock(&svc_xprt_class_lock);
78 /* Make sure there isn't already a class with the same name */
79 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
80 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
81 goto out;
82 }
83 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
84 res = 0;
85out:
86 spin_unlock(&svc_xprt_class_lock);
87 return res;
88}
89EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
90
91void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
92{
93 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
94 spin_lock(&svc_xprt_class_lock);
95 list_del_init(&xcl->xcl_list);
96 spin_unlock(&svc_xprt_class_lock);
97}
98EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
99
100/*
101 * Format the transport list for printing
102 */
103int svc_print_xprts(char *buf, int maxlen)
104{
105 struct svc_xprt_class *xcl;
106 char tmpstr[80];
107 int len = 0;
108 buf[0] = '\0';
109
110 spin_lock(&svc_xprt_class_lock);
111 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
112 int slen;
113
114 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
115 slen = strlen(tmpstr);
116 if (len + slen > maxlen)
117 break;
118 len += slen;
119 strcat(buf, tmpstr);
120 }
121 spin_unlock(&svc_xprt_class_lock);
122
123 return len;
124}
125
126static void svc_xprt_free(struct kref *kref)
127{
128 struct svc_xprt *xprt =
129 container_of(kref, struct svc_xprt, xpt_ref);
130 struct module *owner = xprt->xpt_class->xcl_owner;
131 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
132 svcauth_unix_info_release(xprt);
133 put_net(xprt->xpt_net);
134 /* See comment on corresponding get in xs_setup_bc_tcp(): */
135 if (xprt->xpt_bc_xprt)
136 xprt_put(xprt->xpt_bc_xprt);
137 xprt->xpt_ops->xpo_free(xprt);
138 module_put(owner);
139}
140
141void svc_xprt_put(struct svc_xprt *xprt)
142{
143 kref_put(&xprt->xpt_ref, svc_xprt_free);
144}
145EXPORT_SYMBOL_GPL(svc_xprt_put);
146
147/*
148 * Called by transport drivers to initialize the transport independent
149 * portion of the transport instance.
150 */
151void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
152 struct svc_xprt *xprt, struct svc_serv *serv)
153{
154 memset(xprt, 0, sizeof(*xprt));
155 xprt->xpt_class = xcl;
156 xprt->xpt_ops = xcl->xcl_ops;
157 kref_init(&xprt->xpt_ref);
158 xprt->xpt_server = serv;
159 INIT_LIST_HEAD(&xprt->xpt_list);
160 INIT_LIST_HEAD(&xprt->xpt_ready);
161 INIT_LIST_HEAD(&xprt->xpt_deferred);
162 INIT_LIST_HEAD(&xprt->xpt_users);
163 mutex_init(&xprt->xpt_mutex);
164 spin_lock_init(&xprt->xpt_lock);
165 set_bit(XPT_BUSY, &xprt->xpt_flags);
166 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
167 xprt->xpt_net = get_net(net);
168}
169EXPORT_SYMBOL_GPL(svc_xprt_init);
170
171static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
172 struct svc_serv *serv,
173 struct net *net,
174 const int family,
175 const unsigned short port,
176 int flags)
177{
178 struct sockaddr_in sin = {
179 .sin_family = AF_INET,
180 .sin_addr.s_addr = htonl(INADDR_ANY),
181 .sin_port = htons(port),
182 };
183#if IS_ENABLED(CONFIG_IPV6)
184 struct sockaddr_in6 sin6 = {
185 .sin6_family = AF_INET6,
186 .sin6_addr = IN6ADDR_ANY_INIT,
187 .sin6_port = htons(port),
188 };
189#endif
190 struct sockaddr *sap;
191 size_t len;
192
193 switch (family) {
194 case PF_INET:
195 sap = (struct sockaddr *)&sin;
196 len = sizeof(sin);
197 break;
198#if IS_ENABLED(CONFIG_IPV6)
199 case PF_INET6:
200 sap = (struct sockaddr *)&sin6;
201 len = sizeof(sin6);
202 break;
203#endif
204 default:
205 return ERR_PTR(-EAFNOSUPPORT);
206 }
207
208 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
209}
210
211int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
212 struct net *net, const int family,
213 const unsigned short port, int flags)
214{
215 struct svc_xprt_class *xcl;
216
217 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
218 spin_lock(&svc_xprt_class_lock);
219 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
220 struct svc_xprt *newxprt;
221 unsigned short newport;
222
223 if (strcmp(xprt_name, xcl->xcl_name))
224 continue;
225
226 if (!try_module_get(xcl->xcl_owner))
227 goto err;
228
229 spin_unlock(&svc_xprt_class_lock);
230 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
231 if (IS_ERR(newxprt)) {
232 module_put(xcl->xcl_owner);
233 return PTR_ERR(newxprt);
234 }
235
236 clear_bit(XPT_TEMP, &newxprt->xpt_flags);
237 spin_lock_bh(&serv->sv_lock);
238 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
239 spin_unlock_bh(&serv->sv_lock);
240 newport = svc_xprt_local_port(newxprt);
241 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
242 return newport;
243 }
244 err:
245 spin_unlock(&svc_xprt_class_lock);
246 dprintk("svc: transport %s not found\n", xprt_name);
247
248 /* This errno is exposed to user space. Provide a reasonable
249 * perror msg for a bad transport. */
250 return -EPROTONOSUPPORT;
251}
252EXPORT_SYMBOL_GPL(svc_create_xprt);
253
254/*
255 * Copy the local and remote xprt addresses to the rqstp structure
256 */
257void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
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 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen);
267 rqstp->rq_daddrlen = xprt->xpt_locallen;
268}
269EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
270
271/**
272 * svc_print_addr - Format rq_addr field for printing
273 * @rqstp: svc_rqst struct containing address to print
274 * @buf: target buffer for formatted address
275 * @len: length of target buffer
276 *
277 */
278char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
279{
280 return __svc_print_addr(svc_addr(rqstp), buf, len);
281}
282EXPORT_SYMBOL_GPL(svc_print_addr);
283
284/*
285 * Queue up an idle server thread. Must have pool->sp_lock held.
286 * Note: this is really a stack rather than a queue, so that we only
287 * use as many different threads as we need, and the rest don't pollute
288 * the cache.
289 */
290static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
291{
292 list_add(&rqstp->rq_list, &pool->sp_threads);
293}
294
295/*
296 * Dequeue an nfsd thread. Must have pool->sp_lock held.
297 */
298static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
299{
300 list_del(&rqstp->rq_list);
301}
302
303static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt)
304{
305 if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE)))
306 return true;
307 if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED)))
308 return xprt->xpt_ops->xpo_has_wspace(xprt);
309 return false;
310}
311
312/*
313 * Queue up a transport with data pending. If there are idle nfsd
314 * processes, wake 'em up.
315 *
316 */
317void svc_xprt_enqueue(struct svc_xprt *xprt)
318{
319 struct svc_pool *pool;
320 struct svc_rqst *rqstp;
321 int cpu;
322
323 if (!svc_xprt_has_something_to_do(xprt))
324 return;
325
326 cpu = get_cpu();
327 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
328 put_cpu();
329
330 spin_lock_bh(&pool->sp_lock);
331
332 if (!list_empty(&pool->sp_threads) &&
333 !list_empty(&pool->sp_sockets))
334 printk(KERN_ERR
335 "svc_xprt_enqueue: "
336 "threads and transports both waiting??\n");
337
338 pool->sp_stats.packets++;
339
340 /* Mark transport as busy. It will remain in this state until
341 * the provider calls svc_xprt_received. We update XPT_BUSY
342 * atomically because it also guards against trying to enqueue
343 * the transport twice.
344 */
345 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
346 /* Don't enqueue transport while already enqueued */
347 dprintk("svc: transport %p busy, not enqueued\n", xprt);
348 goto out_unlock;
349 }
350
351 if (!list_empty(&pool->sp_threads)) {
352 rqstp = list_entry(pool->sp_threads.next,
353 struct svc_rqst,
354 rq_list);
355 dprintk("svc: transport %p served by daemon %p\n",
356 xprt, rqstp);
357 svc_thread_dequeue(pool, rqstp);
358 if (rqstp->rq_xprt)
359 printk(KERN_ERR
360 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
361 rqstp, rqstp->rq_xprt);
362 rqstp->rq_xprt = xprt;
363 svc_xprt_get(xprt);
364 pool->sp_stats.threads_woken++;
365 wake_up(&rqstp->rq_wait);
366 } else {
367 dprintk("svc: transport %p put into queue\n", xprt);
368 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
369 pool->sp_stats.sockets_queued++;
370 }
371
372out_unlock:
373 spin_unlock_bh(&pool->sp_lock);
374}
375EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
376
377/*
378 * Dequeue the first transport. Must be called with the pool->sp_lock held.
379 */
380static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
381{
382 struct svc_xprt *xprt;
383
384 if (list_empty(&pool->sp_sockets))
385 return NULL;
386
387 xprt = list_entry(pool->sp_sockets.next,
388 struct svc_xprt, xpt_ready);
389 list_del_init(&xprt->xpt_ready);
390
391 dprintk("svc: transport %p dequeued, inuse=%d\n",
392 xprt, atomic_read(&xprt->xpt_ref.refcount));
393
394 return xprt;
395}
396
397/*
398 * svc_xprt_received conditionally queues the transport for processing
399 * by another thread. The caller must hold the XPT_BUSY bit and must
400 * not thereafter touch transport data.
401 *
402 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
403 * insufficient) data.
404 */
405void svc_xprt_received(struct svc_xprt *xprt)
406{
407 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
408 /* As soon as we clear busy, the xprt could be closed and
409 * 'put', so we need a reference to call svc_xprt_enqueue with:
410 */
411 svc_xprt_get(xprt);
412 clear_bit(XPT_BUSY, &xprt->xpt_flags);
413 svc_xprt_enqueue(xprt);
414 svc_xprt_put(xprt);
415}
416EXPORT_SYMBOL_GPL(svc_xprt_received);
417
418/**
419 * svc_reserve - change the space reserved for the reply to a request.
420 * @rqstp: The request in question
421 * @space: new max space to reserve
422 *
423 * Each request reserves some space on the output queue of the transport
424 * to make sure the reply fits. This function reduces that reserved
425 * space to be the amount of space used already, plus @space.
426 *
427 */
428void svc_reserve(struct svc_rqst *rqstp, int space)
429{
430 space += rqstp->rq_res.head[0].iov_len;
431
432 if (space < rqstp->rq_reserved) {
433 struct svc_xprt *xprt = rqstp->rq_xprt;
434 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
435 rqstp->rq_reserved = space;
436
437 svc_xprt_enqueue(xprt);
438 }
439}
440EXPORT_SYMBOL_GPL(svc_reserve);
441
442static void svc_xprt_release(struct svc_rqst *rqstp)
443{
444 struct svc_xprt *xprt = rqstp->rq_xprt;
445
446 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
447
448 kfree(rqstp->rq_deferred);
449 rqstp->rq_deferred = NULL;
450
451 svc_free_res_pages(rqstp);
452 rqstp->rq_res.page_len = 0;
453 rqstp->rq_res.page_base = 0;
454
455 /* Reset response buffer and release
456 * the reservation.
457 * But first, check that enough space was reserved
458 * for the reply, otherwise we have a bug!
459 */
460 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
461 printk(KERN_ERR "RPC request reserved %d but used %d\n",
462 rqstp->rq_reserved,
463 rqstp->rq_res.len);
464
465 rqstp->rq_res.head[0].iov_len = 0;
466 svc_reserve(rqstp, 0);
467 rqstp->rq_xprt = NULL;
468
469 svc_xprt_put(xprt);
470}
471
472/*
473 * External function to wake up a server waiting for data
474 * This really only makes sense for services like lockd
475 * which have exactly one thread anyway.
476 */
477void svc_wake_up(struct svc_serv *serv)
478{
479 struct svc_rqst *rqstp;
480 unsigned int i;
481 struct svc_pool *pool;
482
483 for (i = 0; i < serv->sv_nrpools; i++) {
484 pool = &serv->sv_pools[i];
485
486 spin_lock_bh(&pool->sp_lock);
487 if (!list_empty(&pool->sp_threads)) {
488 rqstp = list_entry(pool->sp_threads.next,
489 struct svc_rqst,
490 rq_list);
491 dprintk("svc: daemon %p woken up.\n", rqstp);
492 /*
493 svc_thread_dequeue(pool, rqstp);
494 rqstp->rq_xprt = NULL;
495 */
496 wake_up(&rqstp->rq_wait);
497 }
498 spin_unlock_bh(&pool->sp_lock);
499 }
500}
501EXPORT_SYMBOL_GPL(svc_wake_up);
502
503int svc_port_is_privileged(struct sockaddr *sin)
504{
505 switch (sin->sa_family) {
506 case AF_INET:
507 return ntohs(((struct sockaddr_in *)sin)->sin_port)
508 < PROT_SOCK;
509 case AF_INET6:
510 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
511 < PROT_SOCK;
512 default:
513 return 0;
514 }
515}
516
517/*
518 * Make sure that we don't have too many active connections. If we have,
519 * something must be dropped. It's not clear what will happen if we allow
520 * "too many" connections, but when dealing with network-facing software,
521 * we have to code defensively. Here we do that by imposing hard limits.
522 *
523 * There's no point in trying to do random drop here for DoS
524 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
525 * attacker can easily beat that.
526 *
527 * The only somewhat efficient mechanism would be if drop old
528 * connections from the same IP first. But right now we don't even
529 * record the client IP in svc_sock.
530 *
531 * single-threaded services that expect a lot of clients will probably
532 * need to set sv_maxconn to override the default value which is based
533 * on the number of threads
534 */
535static void svc_check_conn_limits(struct svc_serv *serv)
536{
537 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
538 (serv->sv_nrthreads+3) * 20;
539
540 if (serv->sv_tmpcnt > limit) {
541 struct svc_xprt *xprt = NULL;
542 spin_lock_bh(&serv->sv_lock);
543 if (!list_empty(&serv->sv_tempsocks)) {
544 /* Try to help the admin */
545 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
546 serv->sv_name, serv->sv_maxconn ?
547 "max number of connections" :
548 "number of threads");
549 /*
550 * Always select the oldest connection. It's not fair,
551 * but so is life
552 */
553 xprt = list_entry(serv->sv_tempsocks.prev,
554 struct svc_xprt,
555 xpt_list);
556 set_bit(XPT_CLOSE, &xprt->xpt_flags);
557 svc_xprt_get(xprt);
558 }
559 spin_unlock_bh(&serv->sv_lock);
560
561 if (xprt) {
562 svc_xprt_enqueue(xprt);
563 svc_xprt_put(xprt);
564 }
565 }
566}
567
568/*
569 * Receive the next request on any transport. This code is carefully
570 * organised not to touch any cachelines in the shared svc_serv
571 * structure, only cachelines in the local svc_pool.
572 */
573int svc_recv(struct svc_rqst *rqstp, long timeout)
574{
575 struct svc_xprt *xprt = NULL;
576 struct svc_serv *serv = rqstp->rq_server;
577 struct svc_pool *pool = rqstp->rq_pool;
578 int len, i;
579 int pages;
580 struct xdr_buf *arg;
581 DECLARE_WAITQUEUE(wait, current);
582 long time_left;
583
584 dprintk("svc: server %p waiting for data (to = %ld)\n",
585 rqstp, timeout);
586
587 if (rqstp->rq_xprt)
588 printk(KERN_ERR
589 "svc_recv: service %p, transport not NULL!\n",
590 rqstp);
591 if (waitqueue_active(&rqstp->rq_wait))
592 printk(KERN_ERR
593 "svc_recv: service %p, wait queue active!\n",
594 rqstp);
595
596 /* now allocate needed pages. If we get a failure, sleep briefly */
597 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
598 BUG_ON(pages >= RPCSVC_MAXPAGES);
599 for (i = 0; i < pages ; i++)
600 while (rqstp->rq_pages[i] == NULL) {
601 struct page *p = alloc_page(GFP_KERNEL);
602 if (!p) {
603 set_current_state(TASK_INTERRUPTIBLE);
604 if (signalled() || kthread_should_stop()) {
605 set_current_state(TASK_RUNNING);
606 return -EINTR;
607 }
608 schedule_timeout(msecs_to_jiffies(500));
609 }
610 rqstp->rq_pages[i] = p;
611 }
612 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
613
614 /* Make arg->head point to first page and arg->pages point to rest */
615 arg = &rqstp->rq_arg;
616 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
617 arg->head[0].iov_len = PAGE_SIZE;
618 arg->pages = rqstp->rq_pages + 1;
619 arg->page_base = 0;
620 /* save at least one page for response */
621 arg->page_len = (pages-2)*PAGE_SIZE;
622 arg->len = (pages-1)*PAGE_SIZE;
623 arg->tail[0].iov_len = 0;
624
625 try_to_freeze();
626 cond_resched();
627 if (signalled() || kthread_should_stop())
628 return -EINTR;
629
630 /* Normally we will wait up to 5 seconds for any required
631 * cache information to be provided.
632 */
633 rqstp->rq_chandle.thread_wait = 5*HZ;
634
635 spin_lock_bh(&pool->sp_lock);
636 xprt = svc_xprt_dequeue(pool);
637 if (xprt) {
638 rqstp->rq_xprt = xprt;
639 svc_xprt_get(xprt);
640
641 /* As there is a shortage of threads and this request
642 * had to be queued, don't allow the thread to wait so
643 * long for cache updates.
644 */
645 rqstp->rq_chandle.thread_wait = 1*HZ;
646 } else {
647 /* No data pending. Go to sleep */
648 svc_thread_enqueue(pool, rqstp);
649
650 /*
651 * We have to be able to interrupt this wait
652 * to bring down the daemons ...
653 */
654 set_current_state(TASK_INTERRUPTIBLE);
655
656 /*
657 * checking kthread_should_stop() here allows us to avoid
658 * locking and signalling when stopping kthreads that call
659 * svc_recv. If the thread has already been woken up, then
660 * we can exit here without sleeping. If not, then it
661 * it'll be woken up quickly during the schedule_timeout
662 */
663 if (kthread_should_stop()) {
664 set_current_state(TASK_RUNNING);
665 spin_unlock_bh(&pool->sp_lock);
666 return -EINTR;
667 }
668
669 add_wait_queue(&rqstp->rq_wait, &wait);
670 spin_unlock_bh(&pool->sp_lock);
671
672 time_left = schedule_timeout(timeout);
673
674 try_to_freeze();
675
676 spin_lock_bh(&pool->sp_lock);
677 remove_wait_queue(&rqstp->rq_wait, &wait);
678 if (!time_left)
679 pool->sp_stats.threads_timedout++;
680
681 xprt = rqstp->rq_xprt;
682 if (!xprt) {
683 svc_thread_dequeue(pool, rqstp);
684 spin_unlock_bh(&pool->sp_lock);
685 dprintk("svc: server %p, no data yet\n", rqstp);
686 if (signalled() || kthread_should_stop())
687 return -EINTR;
688 else
689 return -EAGAIN;
690 }
691 }
692 spin_unlock_bh(&pool->sp_lock);
693
694 len = 0;
695 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
696 dprintk("svc_recv: found XPT_CLOSE\n");
697 svc_delete_xprt(xprt);
698 /* Leave XPT_BUSY set on the dead xprt: */
699 goto out;
700 }
701 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
702 struct svc_xprt *newxpt;
703 newxpt = xprt->xpt_ops->xpo_accept(xprt);
704 if (newxpt) {
705 /*
706 * We know this module_get will succeed because the
707 * listener holds a reference too
708 */
709 __module_get(newxpt->xpt_class->xcl_owner);
710 svc_check_conn_limits(xprt->xpt_server);
711 spin_lock_bh(&serv->sv_lock);
712 set_bit(XPT_TEMP, &newxpt->xpt_flags);
713 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
714 serv->sv_tmpcnt++;
715 if (serv->sv_temptimer.function == NULL) {
716 /* setup timer to age temp transports */
717 setup_timer(&serv->sv_temptimer,
718 svc_age_temp_xprts,
719 (unsigned long)serv);
720 mod_timer(&serv->sv_temptimer,
721 jiffies + svc_conn_age_period * HZ);
722 }
723 spin_unlock_bh(&serv->sv_lock);
724 svc_xprt_received(newxpt);
725 }
726 } else if (xprt->xpt_ops->xpo_has_wspace(xprt)) {
727 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
728 rqstp, pool->sp_id, xprt,
729 atomic_read(&xprt->xpt_ref.refcount));
730 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
731 if (rqstp->rq_deferred)
732 len = svc_deferred_recv(rqstp);
733 else
734 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
735 dprintk("svc: got len=%d\n", len);
736 rqstp->rq_reserved = serv->sv_max_mesg;
737 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
738 }
739 svc_xprt_received(xprt);
740
741 /* No data, incomplete (TCP) read, or accept() */
742 if (len == 0 || len == -EAGAIN)
743 goto out;
744
745 clear_bit(XPT_OLD, &xprt->xpt_flags);
746
747 rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
748 rqstp->rq_chandle.defer = svc_defer;
749
750 if (serv->sv_stats)
751 serv->sv_stats->netcnt++;
752 return len;
753out:
754 rqstp->rq_res.len = 0;
755 svc_xprt_release(rqstp);
756 return -EAGAIN;
757}
758EXPORT_SYMBOL_GPL(svc_recv);
759
760/*
761 * Drop request
762 */
763void svc_drop(struct svc_rqst *rqstp)
764{
765 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
766 svc_xprt_release(rqstp);
767}
768EXPORT_SYMBOL_GPL(svc_drop);
769
770/*
771 * Return reply to client.
772 */
773int svc_send(struct svc_rqst *rqstp)
774{
775 struct svc_xprt *xprt;
776 int len;
777 struct xdr_buf *xb;
778
779 xprt = rqstp->rq_xprt;
780 if (!xprt)
781 return -EFAULT;
782
783 /* release the receive skb before sending the reply */
784 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
785
786 /* calculate over-all length */
787 xb = &rqstp->rq_res;
788 xb->len = xb->head[0].iov_len +
789 xb->page_len +
790 xb->tail[0].iov_len;
791
792 /* Grab mutex to serialize outgoing data. */
793 mutex_lock(&xprt->xpt_mutex);
794 if (test_bit(XPT_DEAD, &xprt->xpt_flags)
795 || test_bit(XPT_CLOSE, &xprt->xpt_flags))
796 len = -ENOTCONN;
797 else
798 len = xprt->xpt_ops->xpo_sendto(rqstp);
799 mutex_unlock(&xprt->xpt_mutex);
800 rpc_wake_up(&xprt->xpt_bc_pending);
801 svc_xprt_release(rqstp);
802
803 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
804 return 0;
805 return len;
806}
807
808/*
809 * Timer function to close old temporary transports, using
810 * a mark-and-sweep algorithm.
811 */
812static void svc_age_temp_xprts(unsigned long closure)
813{
814 struct svc_serv *serv = (struct svc_serv *)closure;
815 struct svc_xprt *xprt;
816 struct list_head *le, *next;
817 LIST_HEAD(to_be_aged);
818
819 dprintk("svc_age_temp_xprts\n");
820
821 if (!spin_trylock_bh(&serv->sv_lock)) {
822 /* busy, try again 1 sec later */
823 dprintk("svc_age_temp_xprts: busy\n");
824 mod_timer(&serv->sv_temptimer, jiffies + HZ);
825 return;
826 }
827
828 list_for_each_safe(le, next, &serv->sv_tempsocks) {
829 xprt = list_entry(le, struct svc_xprt, xpt_list);
830
831 /* First time through, just mark it OLD. Second time
832 * through, close it. */
833 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
834 continue;
835 if (atomic_read(&xprt->xpt_ref.refcount) > 1 ||
836 test_bit(XPT_BUSY, &xprt->xpt_flags))
837 continue;
838 svc_xprt_get(xprt);
839 list_move(le, &to_be_aged);
840 set_bit(XPT_CLOSE, &xprt->xpt_flags);
841 set_bit(XPT_DETACHED, &xprt->xpt_flags);
842 }
843 spin_unlock_bh(&serv->sv_lock);
844
845 while (!list_empty(&to_be_aged)) {
846 le = to_be_aged.next;
847 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
848 list_del_init(le);
849 xprt = list_entry(le, struct svc_xprt, xpt_list);
850
851 dprintk("queuing xprt %p for closing\n", xprt);
852
853 /* a thread will dequeue and close it soon */
854 svc_xprt_enqueue(xprt);
855 svc_xprt_put(xprt);
856 }
857
858 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
859}
860
861static void call_xpt_users(struct svc_xprt *xprt)
862{
863 struct svc_xpt_user *u;
864
865 spin_lock(&xprt->xpt_lock);
866 while (!list_empty(&xprt->xpt_users)) {
867 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
868 list_del(&u->list);
869 u->callback(u);
870 }
871 spin_unlock(&xprt->xpt_lock);
872}
873
874/*
875 * Remove a dead transport
876 */
877static void svc_delete_xprt(struct svc_xprt *xprt)
878{
879 struct svc_serv *serv = xprt->xpt_server;
880 struct svc_deferred_req *dr;
881
882 /* Only do this once */
883 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
884 BUG();
885
886 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
887 xprt->xpt_ops->xpo_detach(xprt);
888
889 spin_lock_bh(&serv->sv_lock);
890 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
891 list_del_init(&xprt->xpt_list);
892 BUG_ON(!list_empty(&xprt->xpt_ready));
893 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
894 serv->sv_tmpcnt--;
895 spin_unlock_bh(&serv->sv_lock);
896
897 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
898 kfree(dr);
899
900 call_xpt_users(xprt);
901 svc_xprt_put(xprt);
902}
903
904void svc_close_xprt(struct svc_xprt *xprt)
905{
906 set_bit(XPT_CLOSE, &xprt->xpt_flags);
907 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
908 /* someone else will have to effect the close */
909 return;
910 /*
911 * We expect svc_close_xprt() to work even when no threads are
912 * running (e.g., while configuring the server before starting
913 * any threads), so if the transport isn't busy, we delete
914 * it ourself:
915 */
916 svc_delete_xprt(xprt);
917}
918EXPORT_SYMBOL_GPL(svc_close_xprt);
919
920static void svc_close_list(struct list_head *xprt_list, struct net *net)
921{
922 struct svc_xprt *xprt;
923
924 list_for_each_entry(xprt, xprt_list, xpt_list) {
925 if (xprt->xpt_net != net)
926 continue;
927 set_bit(XPT_CLOSE, &xprt->xpt_flags);
928 set_bit(XPT_BUSY, &xprt->xpt_flags);
929 }
930}
931
932static void svc_clear_pools(struct svc_serv *serv, struct net *net)
933{
934 struct svc_pool *pool;
935 struct svc_xprt *xprt;
936 struct svc_xprt *tmp;
937 int i;
938
939 for (i = 0; i < serv->sv_nrpools; i++) {
940 pool = &serv->sv_pools[i];
941
942 spin_lock_bh(&pool->sp_lock);
943 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) {
944 if (xprt->xpt_net != net)
945 continue;
946 list_del_init(&xprt->xpt_ready);
947 }
948 spin_unlock_bh(&pool->sp_lock);
949 }
950}
951
952static void svc_clear_list(struct list_head *xprt_list, struct net *net)
953{
954 struct svc_xprt *xprt;
955 struct svc_xprt *tmp;
956
957 list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
958 if (xprt->xpt_net != net)
959 continue;
960 svc_delete_xprt(xprt);
961 }
962 list_for_each_entry(xprt, xprt_list, xpt_list)
963 BUG_ON(xprt->xpt_net == net);
964}
965
966void svc_close_net(struct svc_serv *serv, struct net *net)
967{
968 svc_close_list(&serv->sv_tempsocks, net);
969 svc_close_list(&serv->sv_permsocks, net);
970
971 svc_clear_pools(serv, net);
972 /*
973 * At this point the sp_sockets lists will stay empty, since
974 * svc_xprt_enqueue will not add new entries without taking the
975 * sp_lock and checking XPT_BUSY.
976 */
977 svc_clear_list(&serv->sv_tempsocks, net);
978 svc_clear_list(&serv->sv_permsocks, net);
979}
980
981/*
982 * Handle defer and revisit of requests
983 */
984
985static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
986{
987 struct svc_deferred_req *dr =
988 container_of(dreq, struct svc_deferred_req, handle);
989 struct svc_xprt *xprt = dr->xprt;
990
991 spin_lock(&xprt->xpt_lock);
992 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
993 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
994 spin_unlock(&xprt->xpt_lock);
995 dprintk("revisit canceled\n");
996 svc_xprt_put(xprt);
997 kfree(dr);
998 return;
999 }
1000 dprintk("revisit queued\n");
1001 dr->xprt = NULL;
1002 list_add(&dr->handle.recent, &xprt->xpt_deferred);
1003 spin_unlock(&xprt->xpt_lock);
1004 svc_xprt_enqueue(xprt);
1005 svc_xprt_put(xprt);
1006}
1007
1008/*
1009 * Save the request off for later processing. The request buffer looks
1010 * like this:
1011 *
1012 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1013 *
1014 * This code can only handle requests that consist of an xprt-header
1015 * and rpc-header.
1016 */
1017static struct cache_deferred_req *svc_defer(struct cache_req *req)
1018{
1019 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1020 struct svc_deferred_req *dr;
1021
1022 if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral)
1023 return NULL; /* if more than a page, give up FIXME */
1024 if (rqstp->rq_deferred) {
1025 dr = rqstp->rq_deferred;
1026 rqstp->rq_deferred = NULL;
1027 } else {
1028 size_t skip;
1029 size_t size;
1030 /* FIXME maybe discard if size too large */
1031 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
1032 dr = kmalloc(size, GFP_KERNEL);
1033 if (dr == NULL)
1034 return NULL;
1035
1036 dr->handle.owner = rqstp->rq_server;
1037 dr->prot = rqstp->rq_prot;
1038 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1039 dr->addrlen = rqstp->rq_addrlen;
1040 dr->daddr = rqstp->rq_daddr;
1041 dr->argslen = rqstp->rq_arg.len >> 2;
1042 dr->xprt_hlen = rqstp->rq_xprt_hlen;
1043
1044 /* back up head to the start of the buffer and copy */
1045 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1046 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1047 dr->argslen << 2);
1048 }
1049 svc_xprt_get(rqstp->rq_xprt);
1050 dr->xprt = rqstp->rq_xprt;
1051 rqstp->rq_dropme = true;
1052
1053 dr->handle.revisit = svc_revisit;
1054 return &dr->handle;
1055}
1056
1057/*
1058 * recv data from a deferred request into an active one
1059 */
1060static int svc_deferred_recv(struct svc_rqst *rqstp)
1061{
1062 struct svc_deferred_req *dr = rqstp->rq_deferred;
1063
1064 /* setup iov_base past transport header */
1065 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1066 /* The iov_len does not include the transport header bytes */
1067 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
1068 rqstp->rq_arg.page_len = 0;
1069 /* The rq_arg.len includes the transport header bytes */
1070 rqstp->rq_arg.len = dr->argslen<<2;
1071 rqstp->rq_prot = dr->prot;
1072 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1073 rqstp->rq_addrlen = dr->addrlen;
1074 /* Save off transport header len in case we get deferred again */
1075 rqstp->rq_xprt_hlen = dr->xprt_hlen;
1076 rqstp->rq_daddr = dr->daddr;
1077 rqstp->rq_respages = rqstp->rq_pages;
1078 return (dr->argslen<<2) - dr->xprt_hlen;
1079}
1080
1081
1082static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1083{
1084 struct svc_deferred_req *dr = NULL;
1085
1086 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1087 return NULL;
1088 spin_lock(&xprt->xpt_lock);
1089 if (!list_empty(&xprt->xpt_deferred)) {
1090 dr = list_entry(xprt->xpt_deferred.next,
1091 struct svc_deferred_req,
1092 handle.recent);
1093 list_del_init(&dr->handle.recent);
1094 } else
1095 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
1096 spin_unlock(&xprt->xpt_lock);
1097 return dr;
1098}
1099
1100/**
1101 * svc_find_xprt - find an RPC transport instance
1102 * @serv: pointer to svc_serv to search
1103 * @xcl_name: C string containing transport's class name
1104 * @net: owner net pointer
1105 * @af: Address family of transport's local address
1106 * @port: transport's IP port number
1107 *
1108 * Return the transport instance pointer for the endpoint accepting
1109 * connections/peer traffic from the specified transport class,
1110 * address family and port.
1111 *
1112 * Specifying 0 for the address family or port is effectively a
1113 * wild-card, and will result in matching the first transport in the
1114 * service's list that has a matching class name.
1115 */
1116struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1117 struct net *net, const sa_family_t af,
1118 const unsigned short port)
1119{
1120 struct svc_xprt *xprt;
1121 struct svc_xprt *found = NULL;
1122
1123 /* Sanity check the args */
1124 if (serv == NULL || xcl_name == NULL)
1125 return found;
1126
1127 spin_lock_bh(&serv->sv_lock);
1128 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1129 if (xprt->xpt_net != net)
1130 continue;
1131 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1132 continue;
1133 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1134 continue;
1135 if (port != 0 && port != svc_xprt_local_port(xprt))
1136 continue;
1137 found = xprt;
1138 svc_xprt_get(xprt);
1139 break;
1140 }
1141 spin_unlock_bh(&serv->sv_lock);
1142 return found;
1143}
1144EXPORT_SYMBOL_GPL(svc_find_xprt);
1145
1146static int svc_one_xprt_name(const struct svc_xprt *xprt,
1147 char *pos, int remaining)
1148{
1149 int len;
1150
1151 len = snprintf(pos, remaining, "%s %u\n",
1152 xprt->xpt_class->xcl_name,
1153 svc_xprt_local_port(xprt));
1154 if (len >= remaining)
1155 return -ENAMETOOLONG;
1156 return len;
1157}
1158
1159/**
1160 * svc_xprt_names - format a buffer with a list of transport names
1161 * @serv: pointer to an RPC service
1162 * @buf: pointer to a buffer to be filled in
1163 * @buflen: length of buffer to be filled in
1164 *
1165 * Fills in @buf with a string containing a list of transport names,
1166 * each name terminated with '\n'.
1167 *
1168 * Returns positive length of the filled-in string on success; otherwise
1169 * a negative errno value is returned if an error occurs.
1170 */
1171int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1172{
1173 struct svc_xprt *xprt;
1174 int len, totlen;
1175 char *pos;
1176
1177 /* Sanity check args */
1178 if (!serv)
1179 return 0;
1180
1181 spin_lock_bh(&serv->sv_lock);
1182
1183 pos = buf;
1184 totlen = 0;
1185 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1186 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1187 if (len < 0) {
1188 *buf = '\0';
1189 totlen = len;
1190 }
1191 if (len <= 0)
1192 break;
1193
1194 pos += len;
1195 totlen += len;
1196 }
1197
1198 spin_unlock_bh(&serv->sv_lock);
1199 return totlen;
1200}
1201EXPORT_SYMBOL_GPL(svc_xprt_names);
1202
1203
1204/*----------------------------------------------------------------------------*/
1205
1206static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1207{
1208 unsigned int pidx = (unsigned int)*pos;
1209 struct svc_serv *serv = m->private;
1210
1211 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1212
1213 if (!pidx)
1214 return SEQ_START_TOKEN;
1215 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1216}
1217
1218static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1219{
1220 struct svc_pool *pool = p;
1221 struct svc_serv *serv = m->private;
1222
1223 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1224
1225 if (p == SEQ_START_TOKEN) {
1226 pool = &serv->sv_pools[0];
1227 } else {
1228 unsigned int pidx = (pool - &serv->sv_pools[0]);
1229 if (pidx < serv->sv_nrpools-1)
1230 pool = &serv->sv_pools[pidx+1];
1231 else
1232 pool = NULL;
1233 }
1234 ++*pos;
1235 return pool;
1236}
1237
1238static void svc_pool_stats_stop(struct seq_file *m, void *p)
1239{
1240}
1241
1242static int svc_pool_stats_show(struct seq_file *m, void *p)
1243{
1244 struct svc_pool *pool = p;
1245
1246 if (p == SEQ_START_TOKEN) {
1247 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1248 return 0;
1249 }
1250
1251 seq_printf(m, "%u %lu %lu %lu %lu\n",
1252 pool->sp_id,
1253 pool->sp_stats.packets,
1254 pool->sp_stats.sockets_queued,
1255 pool->sp_stats.threads_woken,
1256 pool->sp_stats.threads_timedout);
1257
1258 return 0;
1259}
1260
1261static const struct seq_operations svc_pool_stats_seq_ops = {
1262 .start = svc_pool_stats_start,
1263 .next = svc_pool_stats_next,
1264 .stop = svc_pool_stats_stop,
1265 .show = svc_pool_stats_show,
1266};
1267
1268int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1269{
1270 int err;
1271
1272 err = seq_open(file, &svc_pool_stats_seq_ops);
1273 if (!err)
1274 ((struct seq_file *) file->private_data)->private = serv;
1275 return err;
1276}
1277EXPORT_SYMBOL(svc_pool_stats_open);
1278
1279/*----------------------------------------------------------------------------*/