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/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/sunrpc/bc_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_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 */
76
77/**
78 * svc_reg_xprt_class - Register a server-side RPC transport class
79 * @xcl: New transport class to be registered
80 *
81 * Returns zero on success; otherwise a negative errno is returned.
82 */
83int svc_reg_xprt_class(struct svc_xprt_class *xcl)
84{
85 struct svc_xprt_class *cl;
86 int res = -EEXIST;
87
88 INIT_LIST_HEAD(list: &xcl->xcl_list);
89 spin_lock(lock: &svc_xprt_class_lock);
90 /* Make sure there isn't already a class with the same name */
91 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
92 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
93 goto out;
94 }
95 list_add_tail(new: &xcl->xcl_list, head: &svc_xprt_class_list);
96 res = 0;
97out:
98 spin_unlock(lock: &svc_xprt_class_lock);
99 return res;
100}
101EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
102
103/**
104 * svc_unreg_xprt_class - Unregister a server-side RPC transport class
105 * @xcl: Transport class to be unregistered
106 *
107 */
108void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
109{
110 spin_lock(lock: &svc_xprt_class_lock);
111 list_del_init(entry: &xcl->xcl_list);
112 spin_unlock(lock: &svc_xprt_class_lock);
113}
114EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
115
116/**
117 * svc_print_xprts - Format the transport list for printing
118 * @buf: target buffer for formatted address
119 * @maxlen: length of target buffer
120 *
121 * Fills in @buf with a string containing a list of transport names, each name
122 * terminated with '\n'. If the buffer is too small, some entries may be
123 * missing, but it is guaranteed that all lines in the output buffer are
124 * complete.
125 *
126 * Returns positive length of the filled-in string.
127 */
128int svc_print_xprts(char *buf, int maxlen)
129{
130 struct svc_xprt_class *xcl;
131 char tmpstr[80];
132 int len = 0;
133 buf[0] = '\0';
134
135 spin_lock(lock: &svc_xprt_class_lock);
136 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
137 int slen;
138
139 slen = snprintf(buf: tmpstr, size: sizeof(tmpstr), fmt: "%s %d\n",
140 xcl->xcl_name, xcl->xcl_max_payload);
141 if (slen >= sizeof(tmpstr) || len + slen >= maxlen)
142 break;
143 len += slen;
144 strcat(buf, tmpstr);
145 }
146 spin_unlock(lock: &svc_xprt_class_lock);
147
148 return len;
149}
150
151/**
152 * svc_xprt_deferred_close - Close a transport
153 * @xprt: transport instance
154 *
155 * Used in contexts that need to defer the work of shutting down
156 * the transport to an nfsd thread.
157 */
158void svc_xprt_deferred_close(struct svc_xprt *xprt)
159{
160 trace_svc_xprt_close(xprt);
161 if (!test_and_set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags))
162 svc_xprt_enqueue(xprt);
163}
164EXPORT_SYMBOL_GPL(svc_xprt_deferred_close);
165
166static void svc_xprt_free(struct kref *kref)
167{
168 struct svc_xprt *xprt =
169 container_of(kref, struct svc_xprt, xpt_ref);
170 struct module *owner = xprt->xpt_class->xcl_owner;
171 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
172 svcauth_unix_info_release(xpt: xprt);
173 put_cred(cred: xprt->xpt_cred);
174 put_net_track(net: xprt->xpt_net, tracker: &xprt->ns_tracker);
175 /* See comment on corresponding get in xs_setup_bc_tcp(): */
176 if (xprt->xpt_bc_xprt)
177 xprt_put(xprt: xprt->xpt_bc_xprt);
178 if (xprt->xpt_bc_xps)
179 xprt_switch_put(xps: xprt->xpt_bc_xps);
180 trace_svc_xprt_free(xprt);
181 xprt->xpt_ops->xpo_free(xprt);
182 module_put(module: owner);
183}
184
185void svc_xprt_put(struct svc_xprt *xprt)
186{
187 kref_put(kref: &xprt->xpt_ref, release: svc_xprt_free);
188}
189EXPORT_SYMBOL_GPL(svc_xprt_put);
190
191/*
192 * Called by transport drivers to initialize the transport independent
193 * portion of the transport instance.
194 */
195void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
196 struct svc_xprt *xprt, struct svc_serv *serv)
197{
198 memset(s: xprt, c: 0, n: sizeof(*xprt));
199 xprt->xpt_class = xcl;
200 xprt->xpt_ops = xcl->xcl_ops;
201 kref_init(kref: &xprt->xpt_ref);
202 xprt->xpt_server = serv;
203 INIT_LIST_HEAD(list: &xprt->xpt_list);
204 INIT_LIST_HEAD(list: &xprt->xpt_deferred);
205 INIT_LIST_HEAD(list: &xprt->xpt_users);
206 mutex_init(&xprt->xpt_mutex);
207 spin_lock_init(&xprt->xpt_lock);
208 set_bit(nr: XPT_BUSY, addr: &xprt->xpt_flags);
209 xprt->xpt_net = get_net_track(net, tracker: &xprt->ns_tracker, GFP_ATOMIC);
210 strcpy(xprt->xpt_remotebuf, "uninitialized");
211}
212EXPORT_SYMBOL_GPL(svc_xprt_init);
213
214/**
215 * svc_xprt_received - start next receiver thread
216 * @xprt: controlling transport
217 *
218 * The caller must hold the XPT_BUSY bit and must
219 * not thereafter touch transport data.
220 *
221 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
222 * insufficient) data.
223 */
224void svc_xprt_received(struct svc_xprt *xprt)
225{
226 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) {
227 WARN_ONCE(1, "xprt=0x%p already busy!", xprt);
228 return;
229 }
230
231 /* As soon as we clear busy, the xprt could be closed and
232 * 'put', so we need a reference to call svc_xprt_enqueue with:
233 */
234 svc_xprt_get(xprt);
235 smp_mb__before_atomic();
236 clear_bit(nr: XPT_BUSY, addr: &xprt->xpt_flags);
237 svc_xprt_enqueue(xprt);
238 svc_xprt_put(xprt);
239}
240EXPORT_SYMBOL_GPL(svc_xprt_received);
241
242void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new)
243{
244 clear_bit(nr: XPT_TEMP, addr: &new->xpt_flags);
245 spin_lock_bh(lock: &serv->sv_lock);
246 list_add(new: &new->xpt_list, head: &serv->sv_permsocks);
247 spin_unlock_bh(lock: &serv->sv_lock);
248 svc_xprt_received(new);
249}
250
251static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
252 struct net *net, struct sockaddr *sap,
253 size_t len, int flags, const struct cred *cred)
254{
255 struct svc_xprt_class *xcl;
256
257 spin_lock(lock: &svc_xprt_class_lock);
258 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
259 struct svc_xprt *newxprt;
260 unsigned short newport;
261
262 if (strcmp(xprt_name, xcl->xcl_name))
263 continue;
264
265 if (!try_module_get(module: xcl->xcl_owner))
266 goto err;
267
268 spin_unlock(lock: &svc_xprt_class_lock);
269 newxprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
270 if (IS_ERR(ptr: newxprt)) {
271 trace_svc_xprt_create_err(program: serv->sv_programs->pg_name,
272 protocol: xcl->xcl_name, sap, salen: len,
273 xprt: newxprt);
274 module_put(module: xcl->xcl_owner);
275 return PTR_ERR(ptr: newxprt);
276 }
277 newxprt->xpt_cred = get_cred(cred);
278 svc_add_new_perm_xprt(serv, new: newxprt);
279 newport = svc_xprt_local_port(xprt: newxprt);
280 return newport;
281 }
282 err:
283 spin_unlock(lock: &svc_xprt_class_lock);
284 /* This errno is exposed to user space. Provide a reasonable
285 * perror msg for a bad transport. */
286 return -EPROTONOSUPPORT;
287}
288
289/**
290 * svc_xprt_create_from_sa - Add a new listener to @serv from socket address
291 * @serv: target RPC service
292 * @xprt_name: transport class name
293 * @net: network namespace
294 * @sap: socket address pointer
295 * @flags: SVC_SOCK flags
296 * @cred: credential to bind to this transport
297 *
298 * Return local xprt port on success or %-EPROTONOSUPPORT on failure
299 */
300int svc_xprt_create_from_sa(struct svc_serv *serv, const char *xprt_name,
301 struct net *net, struct sockaddr *sap,
302 int flags, const struct cred *cred)
303{
304 size_t len;
305 int err;
306
307 switch (sap->sa_family) {
308 case AF_INET:
309 len = sizeof(struct sockaddr_in);
310 break;
311#if IS_ENABLED(CONFIG_IPV6)
312 case AF_INET6:
313 len = sizeof(struct sockaddr_in6);
314 break;
315#endif
316 default:
317 return -EAFNOSUPPORT;
318 }
319
320 err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags, cred);
321 if (err == -EPROTONOSUPPORT) {
322 request_module("svc%s", xprt_name);
323 err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags,
324 cred);
325 }
326
327 return err;
328}
329EXPORT_SYMBOL_GPL(svc_xprt_create_from_sa);
330
331/**
332 * svc_xprt_create - Add a new listener to @serv
333 * @serv: target RPC service
334 * @xprt_name: transport class name
335 * @net: network namespace
336 * @family: network address family
337 * @port: listener port
338 * @flags: SVC_SOCK flags
339 * @cred: credential to bind to this transport
340 *
341 * Return local xprt port on success or %-EPROTONOSUPPORT on failure
342 */
343int svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
344 struct net *net, const int family,
345 const unsigned short port, int flags,
346 const struct cred *cred)
347{
348 struct sockaddr_in sin = {
349 .sin_family = AF_INET,
350 .sin_addr.s_addr = htonl(INADDR_ANY),
351 .sin_port = htons(port),
352 };
353#if IS_ENABLED(CONFIG_IPV6)
354 struct sockaddr_in6 sin6 = {
355 .sin6_family = AF_INET6,
356 .sin6_addr = IN6ADDR_ANY_INIT,
357 .sin6_port = htons(port),
358 };
359#endif
360 struct sockaddr *sap;
361
362 switch (family) {
363 case PF_INET:
364 sap = (struct sockaddr *)&sin;
365 break;
366#if IS_ENABLED(CONFIG_IPV6)
367 case PF_INET6:
368 sap = (struct sockaddr *)&sin6;
369 break;
370#endif
371 default:
372 return -EAFNOSUPPORT;
373 }
374
375 return svc_xprt_create_from_sa(serv, xprt_name, net, sap, flags, cred);
376}
377EXPORT_SYMBOL_GPL(svc_xprt_create);
378
379/*
380 * Copy the local and remote xprt addresses to the rqstp structure
381 */
382void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
383{
384 memcpy(to: &rqstp->rq_addr, from: &xprt->xpt_remote, len: xprt->xpt_remotelen);
385 rqstp->rq_addrlen = xprt->xpt_remotelen;
386
387 /*
388 * Destination address in request is needed for binding the
389 * source address in RPC replies/callbacks later.
390 */
391 memcpy(to: &rqstp->rq_daddr, from: &xprt->xpt_local, len: xprt->xpt_locallen);
392 rqstp->rq_daddrlen = xprt->xpt_locallen;
393}
394EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
395
396/**
397 * svc_print_addr - Format rq_addr field for printing
398 * @rqstp: svc_rqst struct containing address to print
399 * @buf: target buffer for formatted address
400 * @len: length of target buffer
401 *
402 */
403char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
404{
405 return __svc_print_addr(addr: svc_addr(rqst: rqstp), buf, len);
406}
407EXPORT_SYMBOL_GPL(svc_print_addr);
408
409static bool svc_xprt_slots_in_range(struct svc_xprt *xprt)
410{
411 unsigned int limit = svc_rpc_per_connection_limit;
412 int nrqsts = atomic_read(v: &xprt->xpt_nr_rqsts);
413
414 return limit == 0 || (nrqsts >= 0 && nrqsts < limit);
415}
416
417static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt)
418{
419 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) {
420 if (!svc_xprt_slots_in_range(xprt))
421 return false;
422 atomic_inc(v: &xprt->xpt_nr_rqsts);
423 set_bit(nr: RQ_DATA, addr: &rqstp->rq_flags);
424 }
425 return true;
426}
427
428static void svc_xprt_release_slot(struct svc_rqst *rqstp)
429{
430 struct svc_xprt *xprt = rqstp->rq_xprt;
431 if (test_and_clear_bit(nr: RQ_DATA, addr: &rqstp->rq_flags)) {
432 atomic_dec(v: &xprt->xpt_nr_rqsts);
433 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
434 svc_xprt_enqueue(xprt);
435 }
436}
437
438static bool svc_xprt_ready(struct svc_xprt *xprt)
439{
440 unsigned long xpt_flags;
441
442 /*
443 * If another cpu has recently updated xpt_flags,
444 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to
445 * know about it; otherwise it's possible that both that cpu and
446 * this one could call svc_xprt_enqueue() without either
447 * svc_xprt_enqueue() recognizing that the conditions below
448 * are satisfied, and we could stall indefinitely:
449 */
450 smp_rmb();
451 xpt_flags = READ_ONCE(xprt->xpt_flags);
452
453 trace_svc_xprt_enqueue(xprt, flags: xpt_flags);
454 if (xpt_flags & BIT(XPT_BUSY))
455 return false;
456 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE) | BIT(XPT_HANDSHAKE)))
457 return true;
458 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) {
459 if (xprt->xpt_ops->xpo_has_wspace(xprt) &&
460 svc_xprt_slots_in_range(xprt))
461 return true;
462 trace_svc_xprt_no_write_space(xprt);
463 return false;
464 }
465 return false;
466}
467
468/**
469 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread
470 * @xprt: transport with data pending
471 *
472 */
473void svc_xprt_enqueue(struct svc_xprt *xprt)
474{
475 struct svc_pool *pool;
476
477 if (!svc_xprt_ready(xprt))
478 return;
479
480 /* Mark transport as busy. It will remain in this state until
481 * the provider calls svc_xprt_received. We update XPT_BUSY
482 * atomically because it also guards against trying to enqueue
483 * the transport twice.
484 */
485 if (test_and_set_bit(nr: XPT_BUSY, addr: &xprt->xpt_flags))
486 return;
487
488 pool = svc_pool_for_cpu(serv: xprt->xpt_server);
489
490 percpu_counter_inc(fbc: &pool->sp_sockets_queued);
491 xprt->xpt_qtime = ktime_get();
492 lwq_enqueue(n: &xprt->xpt_ready, q: &pool->sp_xprts);
493
494 svc_pool_wake_idle_thread(pool);
495}
496EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
497
498/*
499 * Dequeue the first transport, if there is one.
500 */
501static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
502{
503 struct svc_xprt *xprt = NULL;
504
505 xprt = lwq_dequeue(&pool->sp_xprts, struct svc_xprt, xpt_ready);
506 if (xprt)
507 svc_xprt_get(xprt);
508 return xprt;
509}
510
511/**
512 * svc_reserve - change the space reserved for the reply to a request.
513 * @rqstp: The request in question
514 * @space: new max space to reserve
515 *
516 * Each request reserves some space on the output queue of the transport
517 * to make sure the reply fits. This function reduces that reserved
518 * space to be the amount of space used already, plus @space.
519 *
520 */
521void svc_reserve(struct svc_rqst *rqstp, int space)
522{
523 struct svc_xprt *xprt = rqstp->rq_xprt;
524
525 space += rqstp->rq_res.head[0].iov_len;
526
527 if (xprt && space < rqstp->rq_reserved) {
528 atomic_sub(i: (rqstp->rq_reserved - space), v: &xprt->xpt_reserved);
529 rqstp->rq_reserved = space;
530 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */
531 svc_xprt_enqueue(xprt);
532 }
533}
534EXPORT_SYMBOL_GPL(svc_reserve);
535
536static void free_deferred(struct svc_xprt *xprt, struct svc_deferred_req *dr)
537{
538 if (!dr)
539 return;
540
541 xprt->xpt_ops->xpo_release_ctxt(xprt, dr->xprt_ctxt);
542 kfree(objp: dr);
543}
544
545static void svc_xprt_release(struct svc_rqst *rqstp)
546{
547 struct svc_xprt *xprt = rqstp->rq_xprt;
548
549 xprt->xpt_ops->xpo_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
550 rqstp->rq_xprt_ctxt = NULL;
551
552 free_deferred(xprt, dr: rqstp->rq_deferred);
553 rqstp->rq_deferred = NULL;
554
555 svc_rqst_release_pages(rqstp);
556 rqstp->rq_res.page_len = 0;
557 rqstp->rq_res.page_base = 0;
558
559 /* Reset response buffer and release
560 * the reservation.
561 * But first, check that enough space was reserved
562 * for the reply, otherwise we have a bug!
563 */
564 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
565 printk(KERN_ERR "RPC request reserved %d but used %d\n",
566 rqstp->rq_reserved,
567 rqstp->rq_res.len);
568
569 rqstp->rq_res.head[0].iov_len = 0;
570 svc_reserve(rqstp, 0);
571 svc_xprt_release_slot(rqstp);
572 rqstp->rq_xprt = NULL;
573 svc_xprt_put(xprt);
574}
575
576/**
577 * svc_wake_up - Wake up a service thread for non-transport work
578 * @serv: RPC service
579 *
580 * Some svc_serv's will have occasional work to do, even when a xprt is not
581 * waiting to be serviced. This function is there to "kick" a task in one of
582 * those services so that it can wake up and do that work. Note that we only
583 * bother with pool 0 as we don't need to wake up more than one thread for
584 * this purpose.
585 */
586void svc_wake_up(struct svc_serv *serv)
587{
588 struct svc_pool *pool = &serv->sv_pools[0];
589
590 set_bit(nr: SP_TASK_PENDING, addr: &pool->sp_flags);
591 svc_pool_wake_idle_thread(pool);
592}
593EXPORT_SYMBOL_GPL(svc_wake_up);
594
595int svc_port_is_privileged(struct sockaddr *sin)
596{
597 switch (sin->sa_family) {
598 case AF_INET:
599 return ntohs(((struct sockaddr_in *)sin)->sin_port)
600 < PROT_SOCK;
601 case AF_INET6:
602 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
603 < PROT_SOCK;
604 default:
605 return 0;
606 }
607}
608
609/*
610 * Make sure that we don't have too many connections that have not yet
611 * demonstrated that they have access to the NFS server. If we have,
612 * something must be dropped. It's not clear what will happen if we allow
613 * "too many" connections, but when dealing with network-facing software,
614 * we have to code defensively. Here we do that by imposing hard limits.
615 *
616 * There's no point in trying to do random drop here for DoS
617 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
618 * attacker can easily beat that.
619 *
620 * The only somewhat efficient mechanism would be if drop old
621 * connections from the same IP first. But right now we don't even
622 * record the client IP in svc_sock.
623 */
624static void svc_check_conn_limits(struct svc_serv *serv)
625{
626 if (serv->sv_tmpcnt > XPT_MAX_TMP_CONN) {
627 struct svc_xprt *xprt = NULL, *xprti;
628 spin_lock_bh(lock: &serv->sv_lock);
629 if (!list_empty(head: &serv->sv_tempsocks)) {
630 /*
631 * Always select the oldest connection. It's not fair,
632 * but nor is life.
633 */
634 list_for_each_entry_reverse(xprti, &serv->sv_tempsocks,
635 xpt_list) {
636 if (!test_bit(XPT_PEER_VALID, &xprti->xpt_flags)) {
637 xprt = xprti;
638 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
639 svc_xprt_get(xprt);
640 break;
641 }
642 }
643 }
644 spin_unlock_bh(lock: &serv->sv_lock);
645
646 if (xprt) {
647 svc_xprt_enqueue(xprt);
648 svc_xprt_put(xprt);
649 }
650 }
651}
652
653static bool svc_alloc_arg(struct svc_rqst *rqstp)
654{
655 struct xdr_buf *arg = &rqstp->rq_arg;
656 unsigned long pages, filled, ret;
657
658 pages = rqstp->rq_maxpages;
659 for (filled = 0; filled < pages; filled = ret) {
660 ret = alloc_pages_bulk(GFP_KERNEL, pages, rqstp->rq_pages);
661 if (ret > filled)
662 /* Made progress, don't sleep yet */
663 continue;
664
665 set_current_state(TASK_IDLE);
666 if (svc_thread_should_stop(rqstp)) {
667 set_current_state(TASK_RUNNING);
668 return false;
669 }
670 trace_svc_alloc_arg_err(requested: pages, allocated: ret);
671 memalloc_retry_wait(GFP_KERNEL);
672 }
673 rqstp->rq_page_end = &rqstp->rq_pages[pages];
674 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */
675
676 /* Make arg->head point to first page and arg->pages point to rest */
677 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
678 arg->head[0].iov_len = PAGE_SIZE;
679 arg->pages = rqstp->rq_pages + 1;
680 arg->page_base = 0;
681 /* save at least one page for response */
682 arg->page_len = (pages-2)*PAGE_SIZE;
683 arg->len = (pages-1)*PAGE_SIZE;
684 arg->tail[0].iov_len = 0;
685
686 rqstp->rq_xid = xdr_zero;
687 return true;
688}
689
690static bool
691svc_thread_should_sleep(struct svc_rqst *rqstp)
692{
693 struct svc_pool *pool = rqstp->rq_pool;
694
695 /* did someone call svc_wake_up? */
696 if (test_bit(SP_TASK_PENDING, &pool->sp_flags))
697 return false;
698
699 /* was a socket queued? */
700 if (!lwq_empty(q: &pool->sp_xprts))
701 return false;
702
703 /* are we shutting down? */
704 if (svc_thread_should_stop(rqstp))
705 return false;
706
707#if defined(CONFIG_SUNRPC_BACKCHANNEL)
708 if (svc_is_backchannel(rqstp)) {
709 if (!lwq_empty(&rqstp->rq_server->sv_cb_list))
710 return false;
711 }
712#endif
713
714 return true;
715}
716
717static void svc_thread_wait_for_work(struct svc_rqst *rqstp)
718{
719 struct svc_pool *pool = rqstp->rq_pool;
720
721 if (svc_thread_should_sleep(rqstp)) {
722 set_current_state(TASK_IDLE | TASK_FREEZABLE);
723 llist_add(new: &rqstp->rq_idle, head: &pool->sp_idle_threads);
724 if (likely(svc_thread_should_sleep(rqstp)))
725 schedule();
726
727 while (!llist_del_first_this(head: &pool->sp_idle_threads,
728 this: &rqstp->rq_idle)) {
729 /* Work just became available. This thread can only
730 * handle it after removing rqstp from the idle
731 * list. If that attempt failed, some other thread
732 * must have queued itself after finding no
733 * work to do, so that thread has taken responsibly
734 * for this new work. This thread can safely sleep
735 * until woken again.
736 */
737 schedule();
738 set_current_state(TASK_IDLE | TASK_FREEZABLE);
739 }
740 __set_current_state(TASK_RUNNING);
741 } else {
742 cond_resched();
743 }
744 try_to_freeze();
745}
746
747static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt)
748{
749 spin_lock_bh(lock: &serv->sv_lock);
750 set_bit(nr: XPT_TEMP, addr: &newxpt->xpt_flags);
751 list_add(new: &newxpt->xpt_list, head: &serv->sv_tempsocks);
752 serv->sv_tmpcnt++;
753 if (serv->sv_temptimer.function == NULL) {
754 /* setup timer to age temp transports */
755 serv->sv_temptimer.function = svc_age_temp_xprts;
756 mod_timer(timer: &serv->sv_temptimer,
757 expires: jiffies + svc_conn_age_period * HZ);
758 }
759 spin_unlock_bh(lock: &serv->sv_lock);
760 svc_xprt_received(newxpt);
761}
762
763static void svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
764{
765 struct svc_serv *serv = rqstp->rq_server;
766 int len = 0;
767
768 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
769 if (test_and_clear_bit(nr: XPT_KILL_TEMP, addr: &xprt->xpt_flags))
770 xprt->xpt_ops->xpo_kill_temp_xprt(xprt);
771 svc_delete_xprt(xprt);
772 /* Leave XPT_BUSY set on the dead xprt: */
773 goto out;
774 }
775 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
776 struct svc_xprt *newxpt;
777 /*
778 * We know this module_get will succeed because the
779 * listener holds a reference too
780 */
781 __module_get(module: xprt->xpt_class->xcl_owner);
782 svc_check_conn_limits(serv: xprt->xpt_server);
783 newxpt = xprt->xpt_ops->xpo_accept(xprt);
784 if (newxpt) {
785 newxpt->xpt_cred = get_cred(cred: xprt->xpt_cred);
786 svc_add_new_temp_xprt(serv, newxpt);
787 trace_svc_xprt_accept(xprt: newxpt, service: serv->sv_name);
788 } else {
789 module_put(module: xprt->xpt_class->xcl_owner);
790 }
791 svc_xprt_received(xprt);
792 } else if (test_bit(XPT_HANDSHAKE, &xprt->xpt_flags)) {
793 xprt->xpt_ops->xpo_handshake(xprt);
794 svc_xprt_received(xprt);
795 } else if (svc_xprt_reserve_slot(rqstp, xprt)) {
796 /* XPT_DATA|XPT_DEFERRED case: */
797 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
798 if (rqstp->rq_deferred)
799 len = svc_deferred_recv(rqstp);
800 else
801 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
802 rqstp->rq_reserved = serv->sv_max_mesg;
803 atomic_add(i: rqstp->rq_reserved, v: &xprt->xpt_reserved);
804 if (len <= 0)
805 goto out;
806
807 trace_svc_xdr_recvfrom(xdr: &rqstp->rq_arg);
808
809 clear_bit(nr: XPT_OLD, addr: &xprt->xpt_flags);
810
811 rqstp->rq_chandle.defer = svc_defer;
812
813 if (serv->sv_stats)
814 serv->sv_stats->netcnt++;
815 percpu_counter_inc(fbc: &rqstp->rq_pool->sp_messages_arrived);
816 rqstp->rq_stime = ktime_get();
817 svc_process(rqstp);
818 } else
819 svc_xprt_received(xprt);
820
821out:
822 rqstp->rq_res.len = 0;
823 svc_xprt_release(rqstp);
824}
825
826static void svc_thread_wake_next(struct svc_rqst *rqstp)
827{
828 if (!svc_thread_should_sleep(rqstp))
829 /* More work pending after I dequeued some,
830 * wake another worker
831 */
832 svc_pool_wake_idle_thread(pool: rqstp->rq_pool);
833}
834
835/**
836 * svc_recv - Receive and process the next request on any transport
837 * @rqstp: an idle RPC service thread
838 *
839 * This code is carefully organised not to touch any cachelines in
840 * the shared svc_serv structure, only cachelines in the local
841 * svc_pool.
842 */
843void svc_recv(struct svc_rqst *rqstp)
844{
845 struct svc_pool *pool = rqstp->rq_pool;
846
847 if (!svc_alloc_arg(rqstp))
848 return;
849
850 svc_thread_wait_for_work(rqstp);
851
852 clear_bit(nr: SP_TASK_PENDING, addr: &pool->sp_flags);
853
854 if (svc_thread_should_stop(rqstp)) {
855 svc_thread_wake_next(rqstp);
856 return;
857 }
858
859 rqstp->rq_xprt = svc_xprt_dequeue(pool);
860 if (rqstp->rq_xprt) {
861 struct svc_xprt *xprt = rqstp->rq_xprt;
862
863 svc_thread_wake_next(rqstp);
864 /* Normally we will wait up to 5 seconds for any required
865 * cache information to be provided. When there are no
866 * idle threads, we reduce the wait time.
867 */
868 if (pool->sp_idle_threads.first)
869 rqstp->rq_chandle.thread_wait = 5 * HZ;
870 else
871 rqstp->rq_chandle.thread_wait = 1 * HZ;
872
873 trace_svc_xprt_dequeue(rqst: rqstp);
874 svc_handle_xprt(rqstp, xprt);
875 }
876
877#if defined(CONFIG_SUNRPC_BACKCHANNEL)
878 if (svc_is_backchannel(rqstp)) {
879 struct svc_serv *serv = rqstp->rq_server;
880 struct rpc_rqst *req;
881
882 req = lwq_dequeue(&serv->sv_cb_list,
883 struct rpc_rqst, rq_bc_list);
884 if (req) {
885 svc_thread_wake_next(rqstp);
886 svc_process_bc(req, rqstp);
887 }
888 }
889#endif
890}
891EXPORT_SYMBOL_GPL(svc_recv);
892
893/**
894 * svc_send - Return reply to client
895 * @rqstp: RPC transaction context
896 *
897 */
898void svc_send(struct svc_rqst *rqstp)
899{
900 struct svc_xprt *xprt;
901 struct xdr_buf *xb;
902 int status;
903
904 xprt = rqstp->rq_xprt;
905
906 /* calculate over-all length */
907 xb = &rqstp->rq_res;
908 xb->len = xb->head[0].iov_len +
909 xb->page_len +
910 xb->tail[0].iov_len;
911 trace_svc_xdr_sendto(xid: rqstp->rq_xid, xdr: xb);
912 trace_svc_stats_latency(rqst: rqstp);
913
914 status = xprt->xpt_ops->xpo_sendto(rqstp);
915
916 trace_svc_send(rqst: rqstp, status);
917}
918
919/*
920 * Timer function to close old temporary transports, using
921 * a mark-and-sweep algorithm.
922 */
923static void svc_age_temp_xprts(struct timer_list *t)
924{
925 struct svc_serv *serv = timer_container_of(serv, t, sv_temptimer);
926 struct svc_xprt *xprt;
927 struct list_head *le, *next;
928
929 dprintk("svc_age_temp_xprts\n");
930
931 if (!spin_trylock_bh(lock: &serv->sv_lock)) {
932 /* busy, try again 1 sec later */
933 dprintk("svc_age_temp_xprts: busy\n");
934 mod_timer(timer: &serv->sv_temptimer, expires: jiffies + HZ);
935 return;
936 }
937
938 list_for_each_safe(le, next, &serv->sv_tempsocks) {
939 xprt = list_entry(le, struct svc_xprt, xpt_list);
940
941 /* First time through, just mark it OLD. Second time
942 * through, close it. */
943 if (!test_and_set_bit(nr: XPT_OLD, addr: &xprt->xpt_flags))
944 continue;
945 if (kref_read(kref: &xprt->xpt_ref) > 1 ||
946 test_bit(XPT_BUSY, &xprt->xpt_flags))
947 continue;
948 list_del_init(entry: le);
949 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
950 dprintk("queuing xprt %p for closing\n", xprt);
951
952 /* a thread will dequeue and close it soon */
953 svc_xprt_enqueue(xprt);
954 }
955 spin_unlock_bh(lock: &serv->sv_lock);
956
957 mod_timer(timer: &serv->sv_temptimer, expires: jiffies + svc_conn_age_period * HZ);
958}
959
960/* Close temporary transports whose xpt_local matches server_addr immediately
961 * instead of waiting for them to be picked up by the timer.
962 *
963 * This is meant to be called from a notifier_block that runs when an ip
964 * address is deleted.
965 */
966void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr)
967{
968 struct svc_xprt *xprt;
969 struct list_head *le, *next;
970 LIST_HEAD(to_be_closed);
971
972 spin_lock_bh(lock: &serv->sv_lock);
973 list_for_each_safe(le, next, &serv->sv_tempsocks) {
974 xprt = list_entry(le, struct svc_xprt, xpt_list);
975 if (rpc_cmp_addr(sap1: server_addr, sap2: (struct sockaddr *)
976 &xprt->xpt_local)) {
977 dprintk("svc_age_temp_xprts_now: found %p\n", xprt);
978 list_move(list: le, head: &to_be_closed);
979 }
980 }
981 spin_unlock_bh(lock: &serv->sv_lock);
982
983 while (!list_empty(head: &to_be_closed)) {
984 le = to_be_closed.next;
985 list_del_init(entry: le);
986 xprt = list_entry(le, struct svc_xprt, xpt_list);
987 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
988 set_bit(nr: XPT_KILL_TEMP, addr: &xprt->xpt_flags);
989 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
990 xprt);
991 svc_xprt_enqueue(xprt);
992 }
993}
994EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);
995
996static void call_xpt_users(struct svc_xprt *xprt)
997{
998 struct svc_xpt_user *u;
999
1000 spin_lock(lock: &xprt->xpt_lock);
1001 while (!list_empty(head: &xprt->xpt_users)) {
1002 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
1003 list_del_init(entry: &u->list);
1004 u->callback(u);
1005 }
1006 spin_unlock(lock: &xprt->xpt_lock);
1007}
1008
1009/*
1010 * Remove a dead transport
1011 */
1012static void svc_delete_xprt(struct svc_xprt *xprt)
1013{
1014 struct svc_serv *serv = xprt->xpt_server;
1015 struct svc_deferred_req *dr;
1016
1017 /* unregister with rpcbind for when transport type is TCP or UDP.
1018 */
1019 if (test_bit(XPT_RPCB_UNREG, &xprt->xpt_flags)) {
1020 struct svc_sock *svsk = container_of(xprt, struct svc_sock,
1021 sk_xprt);
1022 struct socket *sock = svsk->sk_sock;
1023
1024 if (svc_register(serv, xprt->xpt_net, sock->sk->sk_family,
1025 sock->sk->sk_protocol, 0) < 0)
1026 pr_warn("failed to unregister %s with rpcbind\n",
1027 xprt->xpt_class->xcl_name);
1028 }
1029
1030 if (test_and_set_bit(nr: XPT_DEAD, addr: &xprt->xpt_flags))
1031 return;
1032
1033 trace_svc_xprt_detach(xprt);
1034 xprt->xpt_ops->xpo_detach(xprt);
1035 if (xprt->xpt_bc_xprt)
1036 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt);
1037
1038 spin_lock_bh(lock: &serv->sv_lock);
1039 list_del_init(entry: &xprt->xpt_list);
1040 if (test_bit(XPT_TEMP, &xprt->xpt_flags) &&
1041 !test_bit(XPT_PEER_VALID, &xprt->xpt_flags))
1042 serv->sv_tmpcnt--;
1043 spin_unlock_bh(lock: &serv->sv_lock);
1044
1045 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
1046 free_deferred(xprt, dr);
1047
1048 call_xpt_users(xprt);
1049 svc_xprt_put(xprt);
1050}
1051
1052/**
1053 * svc_xprt_close - Close a client connection
1054 * @xprt: transport to disconnect
1055 *
1056 */
1057void svc_xprt_close(struct svc_xprt *xprt)
1058{
1059 trace_svc_xprt_close(xprt);
1060 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
1061 if (test_and_set_bit(nr: XPT_BUSY, addr: &xprt->xpt_flags))
1062 /* someone else will have to effect the close */
1063 return;
1064 /*
1065 * We expect svc_close_xprt() to work even when no threads are
1066 * running (e.g., while configuring the server before starting
1067 * any threads), so if the transport isn't busy, we delete
1068 * it ourself:
1069 */
1070 svc_delete_xprt(xprt);
1071}
1072EXPORT_SYMBOL_GPL(svc_xprt_close);
1073
1074static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net)
1075{
1076 struct svc_xprt *xprt;
1077 int ret = 0;
1078
1079 spin_lock_bh(lock: &serv->sv_lock);
1080 list_for_each_entry(xprt, xprt_list, xpt_list) {
1081 if (xprt->xpt_net != net)
1082 continue;
1083 ret++;
1084 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
1085 svc_xprt_enqueue(xprt);
1086 }
1087 spin_unlock_bh(lock: &serv->sv_lock);
1088 return ret;
1089}
1090
1091static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net)
1092{
1093 struct svc_xprt *xprt;
1094 int i;
1095
1096 for (i = 0; i < serv->sv_nrpools; i++) {
1097 struct svc_pool *pool = &serv->sv_pools[i];
1098 struct llist_node *q, **t1, *t2;
1099
1100 q = lwq_dequeue_all(q: &pool->sp_xprts);
1101 lwq_for_each_safe(xprt, t1, t2, &q, xpt_ready) {
1102 if (xprt->xpt_net == net) {
1103 set_bit(nr: XPT_CLOSE, addr: &xprt->xpt_flags);
1104 svc_delete_xprt(xprt);
1105 xprt = NULL;
1106 }
1107 }
1108
1109 if (q)
1110 lwq_enqueue_batch(n: q, q: &pool->sp_xprts);
1111 }
1112}
1113
1114/**
1115 * svc_xprt_destroy_all - Destroy transports associated with @serv
1116 * @serv: RPC service to be shut down
1117 * @net: target network namespace
1118 * @unregister: true if it is OK to unregister the destroyed xprts
1119 *
1120 * Server threads may still be running (especially in the case where the
1121 * service is still running in other network namespaces).
1122 *
1123 * So we shut down sockets the same way we would on a running server, by
1124 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do
1125 * the close. In the case there are no such other threads,
1126 * threads running, svc_clean_up_xprts() does a simple version of a
1127 * server's main event loop, and in the case where there are other
1128 * threads, we may need to wait a little while and then check again to
1129 * see if they're done.
1130 */
1131void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net,
1132 bool unregister)
1133{
1134 int delay = 0;
1135
1136 while (svc_close_list(serv, xprt_list: &serv->sv_permsocks, net) +
1137 svc_close_list(serv, xprt_list: &serv->sv_tempsocks, net)) {
1138
1139 svc_clean_up_xprts(serv, net);
1140 msleep(msecs: delay++);
1141 }
1142
1143 if (unregister)
1144 svc_rpcb_cleanup(serv, net);
1145}
1146EXPORT_SYMBOL_GPL(svc_xprt_destroy_all);
1147
1148/*
1149 * Handle defer and revisit of requests
1150 */
1151
1152static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
1153{
1154 struct svc_deferred_req *dr =
1155 container_of(dreq, struct svc_deferred_req, handle);
1156 struct svc_xprt *xprt = dr->xprt;
1157
1158 spin_lock(lock: &xprt->xpt_lock);
1159 set_bit(nr: XPT_DEFERRED, addr: &xprt->xpt_flags);
1160 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
1161 spin_unlock(lock: &xprt->xpt_lock);
1162 trace_svc_defer_drop(dr);
1163 free_deferred(xprt, dr);
1164 svc_xprt_put(xprt);
1165 return;
1166 }
1167 dr->xprt = NULL;
1168 list_add(new: &dr->handle.recent, head: &xprt->xpt_deferred);
1169 spin_unlock(lock: &xprt->xpt_lock);
1170 trace_svc_defer_queue(dr);
1171 svc_xprt_enqueue(xprt);
1172 svc_xprt_put(xprt);
1173}
1174
1175/*
1176 * Save the request off for later processing. The request buffer looks
1177 * like this:
1178 *
1179 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1180 *
1181 * This code can only handle requests that consist of an xprt-header
1182 * and rpc-header.
1183 */
1184static struct cache_deferred_req *svc_defer(struct cache_req *req)
1185{
1186 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1187 struct svc_deferred_req *dr;
1188
1189 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags))
1190 return NULL; /* if more than a page, give up FIXME */
1191 if (rqstp->rq_deferred) {
1192 dr = rqstp->rq_deferred;
1193 rqstp->rq_deferred = NULL;
1194 } else {
1195 size_t skip;
1196 size_t size;
1197 /* FIXME maybe discard if size too large */
1198 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
1199 dr = kmalloc(size, GFP_KERNEL);
1200 if (dr == NULL)
1201 return NULL;
1202
1203 dr->handle.owner = rqstp->rq_server;
1204 dr->prot = rqstp->rq_prot;
1205 memcpy(to: &dr->addr, from: &rqstp->rq_addr, len: rqstp->rq_addrlen);
1206 dr->addrlen = rqstp->rq_addrlen;
1207 dr->daddr = rqstp->rq_daddr;
1208 dr->argslen = rqstp->rq_arg.len >> 2;
1209
1210 /* back up head to the start of the buffer and copy */
1211 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1212 memcpy(to: dr->args, from: rqstp->rq_arg.head[0].iov_base - skip,
1213 len: dr->argslen << 2);
1214 }
1215 dr->xprt_ctxt = rqstp->rq_xprt_ctxt;
1216 rqstp->rq_xprt_ctxt = NULL;
1217 trace_svc_defer(rqst: rqstp);
1218 svc_xprt_get(xprt: rqstp->rq_xprt);
1219 dr->xprt = rqstp->rq_xprt;
1220 set_bit(nr: RQ_DROPME, addr: &rqstp->rq_flags);
1221
1222 dr->handle.revisit = svc_revisit;
1223 return &dr->handle;
1224}
1225
1226/*
1227 * recv data from a deferred request into an active one
1228 */
1229static noinline int svc_deferred_recv(struct svc_rqst *rqstp)
1230{
1231 struct svc_deferred_req *dr = rqstp->rq_deferred;
1232
1233 trace_svc_defer_recv(dr);
1234
1235 /* setup iov_base past transport header */
1236 rqstp->rq_arg.head[0].iov_base = dr->args;
1237 /* The iov_len does not include the transport header bytes */
1238 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2;
1239 rqstp->rq_arg.page_len = 0;
1240 /* The rq_arg.len includes the transport header bytes */
1241 rqstp->rq_arg.len = dr->argslen << 2;
1242 rqstp->rq_prot = dr->prot;
1243 memcpy(to: &rqstp->rq_addr, from: &dr->addr, len: dr->addrlen);
1244 rqstp->rq_addrlen = dr->addrlen;
1245 /* Save off transport header len in case we get deferred again */
1246 rqstp->rq_daddr = dr->daddr;
1247 rqstp->rq_respages = rqstp->rq_pages;
1248 rqstp->rq_xprt_ctxt = dr->xprt_ctxt;
1249
1250 dr->xprt_ctxt = NULL;
1251 svc_xprt_received(rqstp->rq_xprt);
1252 return dr->argslen << 2;
1253}
1254
1255
1256static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1257{
1258 struct svc_deferred_req *dr = NULL;
1259
1260 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1261 return NULL;
1262 spin_lock(lock: &xprt->xpt_lock);
1263 if (!list_empty(head: &xprt->xpt_deferred)) {
1264 dr = list_entry(xprt->xpt_deferred.next,
1265 struct svc_deferred_req,
1266 handle.recent);
1267 list_del_init(entry: &dr->handle.recent);
1268 } else
1269 clear_bit(nr: XPT_DEFERRED, addr: &xprt->xpt_flags);
1270 spin_unlock(lock: &xprt->xpt_lock);
1271 return dr;
1272}
1273
1274/**
1275 * svc_find_listener - find an RPC transport instance
1276 * @serv: pointer to svc_serv to search
1277 * @xcl_name: C string containing transport's class name
1278 * @net: owner net pointer
1279 * @sa: sockaddr containing address
1280 *
1281 * Return the transport instance pointer for the endpoint accepting
1282 * connections/peer traffic from the specified transport class,
1283 * and matching sockaddr.
1284 */
1285struct svc_xprt *svc_find_listener(struct svc_serv *serv, const char *xcl_name,
1286 struct net *net, const struct sockaddr *sa)
1287{
1288 struct svc_xprt *xprt;
1289 struct svc_xprt *found = NULL;
1290
1291 spin_lock_bh(lock: &serv->sv_lock);
1292 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1293 if (xprt->xpt_net != net)
1294 continue;
1295 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1296 continue;
1297 if (!rpc_cmp_addr_port(sap1: sa, sap2: (struct sockaddr *)&xprt->xpt_local))
1298 continue;
1299 found = xprt;
1300 svc_xprt_get(xprt);
1301 break;
1302 }
1303 spin_unlock_bh(lock: &serv->sv_lock);
1304 return found;
1305}
1306EXPORT_SYMBOL_GPL(svc_find_listener);
1307
1308/**
1309 * svc_find_xprt - find an RPC transport instance
1310 * @serv: pointer to svc_serv to search
1311 * @xcl_name: C string containing transport's class name
1312 * @net: owner net pointer
1313 * @af: Address family of transport's local address
1314 * @port: transport's IP port number
1315 *
1316 * Return the transport instance pointer for the endpoint accepting
1317 * connections/peer traffic from the specified transport class,
1318 * address family and port.
1319 *
1320 * Specifying 0 for the address family or port is effectively a
1321 * wild-card, and will result in matching the first transport in the
1322 * service's list that has a matching class name.
1323 */
1324struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1325 struct net *net, const sa_family_t af,
1326 const unsigned short port)
1327{
1328 struct svc_xprt *xprt;
1329 struct svc_xprt *found = NULL;
1330
1331 /* Sanity check the args */
1332 if (serv == NULL || xcl_name == NULL)
1333 return found;
1334
1335 spin_lock_bh(lock: &serv->sv_lock);
1336 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1337 if (xprt->xpt_net != net)
1338 continue;
1339 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1340 continue;
1341 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1342 continue;
1343 if (port != 0 && port != svc_xprt_local_port(xprt))
1344 continue;
1345 found = xprt;
1346 svc_xprt_get(xprt);
1347 break;
1348 }
1349 spin_unlock_bh(lock: &serv->sv_lock);
1350 return found;
1351}
1352EXPORT_SYMBOL_GPL(svc_find_xprt);
1353
1354static int svc_one_xprt_name(const struct svc_xprt *xprt,
1355 char *pos, int remaining)
1356{
1357 int len;
1358
1359 len = snprintf(buf: pos, size: remaining, fmt: "%s %u\n",
1360 xprt->xpt_class->xcl_name,
1361 svc_xprt_local_port(xprt));
1362 if (len >= remaining)
1363 return -ENAMETOOLONG;
1364 return len;
1365}
1366
1367/**
1368 * svc_xprt_names - format a buffer with a list of transport names
1369 * @serv: pointer to an RPC service
1370 * @buf: pointer to a buffer to be filled in
1371 * @buflen: length of buffer to be filled in
1372 *
1373 * Fills in @buf with a string containing a list of transport names,
1374 * each name terminated with '\n'.
1375 *
1376 * Returns positive length of the filled-in string on success; otherwise
1377 * a negative errno value is returned if an error occurs.
1378 */
1379int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
1380{
1381 struct svc_xprt *xprt;
1382 int len, totlen;
1383 char *pos;
1384
1385 /* Sanity check args */
1386 if (!serv)
1387 return 0;
1388
1389 spin_lock_bh(lock: &serv->sv_lock);
1390
1391 pos = buf;
1392 totlen = 0;
1393 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1394 len = svc_one_xprt_name(xprt, pos, remaining: buflen - totlen);
1395 if (len < 0) {
1396 *buf = '\0';
1397 totlen = len;
1398 }
1399 if (len <= 0)
1400 break;
1401
1402 pos += len;
1403 totlen += len;
1404 }
1405
1406 spin_unlock_bh(lock: &serv->sv_lock);
1407 return totlen;
1408}
1409EXPORT_SYMBOL_GPL(svc_xprt_names);
1410
1411/*----------------------------------------------------------------------------*/
1412
1413static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1414{
1415 unsigned int pidx = (unsigned int)*pos;
1416 struct svc_info *si = m->private;
1417
1418 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1419
1420 mutex_lock(lock: si->mutex);
1421
1422 if (!pidx)
1423 return SEQ_START_TOKEN;
1424 if (!si->serv)
1425 return NULL;
1426 return pidx > si->serv->sv_nrpools ? NULL
1427 : &si->serv->sv_pools[pidx - 1];
1428}
1429
1430static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1431{
1432 struct svc_pool *pool = p;
1433 struct svc_info *si = m->private;
1434 struct svc_serv *serv = si->serv;
1435
1436 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1437
1438 if (!serv) {
1439 pool = NULL;
1440 } else if (p == SEQ_START_TOKEN) {
1441 pool = &serv->sv_pools[0];
1442 } else {
1443 unsigned int pidx = (pool - &serv->sv_pools[0]);
1444 if (pidx < serv->sv_nrpools-1)
1445 pool = &serv->sv_pools[pidx+1];
1446 else
1447 pool = NULL;
1448 }
1449 ++*pos;
1450 return pool;
1451}
1452
1453static void svc_pool_stats_stop(struct seq_file *m, void *p)
1454{
1455 struct svc_info *si = m->private;
1456
1457 mutex_unlock(lock: si->mutex);
1458}
1459
1460static int svc_pool_stats_show(struct seq_file *m, void *p)
1461{
1462 struct svc_pool *pool = p;
1463
1464 if (p == SEQ_START_TOKEN) {
1465 seq_puts(m, s: "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1466 return 0;
1467 }
1468
1469 seq_printf(m, fmt: "%u %llu %llu %llu 0\n",
1470 pool->sp_id,
1471 percpu_counter_sum_positive(fbc: &pool->sp_messages_arrived),
1472 percpu_counter_sum_positive(fbc: &pool->sp_sockets_queued),
1473 percpu_counter_sum_positive(fbc: &pool->sp_threads_woken));
1474
1475 return 0;
1476}
1477
1478static const struct seq_operations svc_pool_stats_seq_ops = {
1479 .start = svc_pool_stats_start,
1480 .next = svc_pool_stats_next,
1481 .stop = svc_pool_stats_stop,
1482 .show = svc_pool_stats_show,
1483};
1484
1485int svc_pool_stats_open(struct svc_info *info, struct file *file)
1486{
1487 struct seq_file *seq;
1488 int err;
1489
1490 err = seq_open(file, &svc_pool_stats_seq_ops);
1491 if (err)
1492 return err;
1493 seq = file->private_data;
1494 seq->private = info;
1495
1496 return 0;
1497}
1498EXPORT_SYMBOL(svc_pool_stats_open);
1499
1500/*----------------------------------------------------------------------------*/
1501