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1/*
2 * linux/net/sunrpc/svc.c
3 *
4 * High-level RPC service routines
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 *
8 * Multiple threads pools and NUMAisation
9 * Copyright (c) 2006 Silicon Graphics, Inc.
10 * by Greg Banks <gnb@melbourne.sgi.com>
11 */
12
13#include <linux/linkage.h>
14#include <linux/sched/signal.h>
15#include <linux/errno.h>
16#include <linux/net.h>
17#include <linux/in.h>
18#include <linux/mm.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/kthread.h>
22#include <linux/slab.h>
23
24#include <linux/sunrpc/types.h>
25#include <linux/sunrpc/xdr.h>
26#include <linux/sunrpc/stats.h>
27#include <linux/sunrpc/svcsock.h>
28#include <linux/sunrpc/clnt.h>
29#include <linux/sunrpc/bc_xprt.h>
30
31#include <trace/events/sunrpc.h>
32
33#define RPCDBG_FACILITY RPCDBG_SVCDSP
34
35static void svc_unregister(const struct svc_serv *serv, struct net *net);
36
37#define svc_serv_is_pooled(serv) ((serv)->sv_ops->svo_function)
38
39#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
40
41/*
42 * Structure for mapping cpus to pools and vice versa.
43 * Setup once during sunrpc initialisation.
44 */
45struct svc_pool_map svc_pool_map = {
46 .mode = SVC_POOL_DEFAULT
47};
48EXPORT_SYMBOL_GPL(svc_pool_map);
49
50static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
51
52static int
53param_set_pool_mode(const char *val, const struct kernel_param *kp)
54{
55 int *ip = (int *)kp->arg;
56 struct svc_pool_map *m = &svc_pool_map;
57 int err;
58
59 mutex_lock(&svc_pool_map_mutex);
60
61 err = -EBUSY;
62 if (m->count)
63 goto out;
64
65 err = 0;
66 if (!strncmp(val, "auto", 4))
67 *ip = SVC_POOL_AUTO;
68 else if (!strncmp(val, "global", 6))
69 *ip = SVC_POOL_GLOBAL;
70 else if (!strncmp(val, "percpu", 6))
71 *ip = SVC_POOL_PERCPU;
72 else if (!strncmp(val, "pernode", 7))
73 *ip = SVC_POOL_PERNODE;
74 else
75 err = -EINVAL;
76
77out:
78 mutex_unlock(&svc_pool_map_mutex);
79 return err;
80}
81
82static int
83param_get_pool_mode(char *buf, const struct kernel_param *kp)
84{
85 int *ip = (int *)kp->arg;
86
87 switch (*ip)
88 {
89 case SVC_POOL_AUTO:
90 return strlcpy(buf, "auto", 20);
91 case SVC_POOL_GLOBAL:
92 return strlcpy(buf, "global", 20);
93 case SVC_POOL_PERCPU:
94 return strlcpy(buf, "percpu", 20);
95 case SVC_POOL_PERNODE:
96 return strlcpy(buf, "pernode", 20);
97 default:
98 return sprintf(buf, "%d", *ip);
99 }
100}
101
102module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
103 &svc_pool_map.mode, 0644);
104
105/*
106 * Detect best pool mapping mode heuristically,
107 * according to the machine's topology.
108 */
109static int
110svc_pool_map_choose_mode(void)
111{
112 unsigned int node;
113
114 if (nr_online_nodes > 1) {
115 /*
116 * Actually have multiple NUMA nodes,
117 * so split pools on NUMA node boundaries
118 */
119 return SVC_POOL_PERNODE;
120 }
121
122 node = first_online_node;
123 if (nr_cpus_node(node) > 2) {
124 /*
125 * Non-trivial SMP, or CONFIG_NUMA on
126 * non-NUMA hardware, e.g. with a generic
127 * x86_64 kernel on Xeons. In this case we
128 * want to divide the pools on cpu boundaries.
129 */
130 return SVC_POOL_PERCPU;
131 }
132
133 /* default: one global pool */
134 return SVC_POOL_GLOBAL;
135}
136
137/*
138 * Allocate the to_pool[] and pool_to[] arrays.
139 * Returns 0 on success or an errno.
140 */
141static int
142svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
143{
144 m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
145 if (!m->to_pool)
146 goto fail;
147 m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
148 if (!m->pool_to)
149 goto fail_free;
150
151 return 0;
152
153fail_free:
154 kfree(m->to_pool);
155 m->to_pool = NULL;
156fail:
157 return -ENOMEM;
158}
159
160/*
161 * Initialise the pool map for SVC_POOL_PERCPU mode.
162 * Returns number of pools or <0 on error.
163 */
164static int
165svc_pool_map_init_percpu(struct svc_pool_map *m)
166{
167 unsigned int maxpools = nr_cpu_ids;
168 unsigned int pidx = 0;
169 unsigned int cpu;
170 int err;
171
172 err = svc_pool_map_alloc_arrays(m, maxpools);
173 if (err)
174 return err;
175
176 for_each_online_cpu(cpu) {
177 BUG_ON(pidx >= maxpools);
178 m->to_pool[cpu] = pidx;
179 m->pool_to[pidx] = cpu;
180 pidx++;
181 }
182 /* cpus brought online later all get mapped to pool0, sorry */
183
184 return pidx;
185};
186
187
188/*
189 * Initialise the pool map for SVC_POOL_PERNODE mode.
190 * Returns number of pools or <0 on error.
191 */
192static int
193svc_pool_map_init_pernode(struct svc_pool_map *m)
194{
195 unsigned int maxpools = nr_node_ids;
196 unsigned int pidx = 0;
197 unsigned int node;
198 int err;
199
200 err = svc_pool_map_alloc_arrays(m, maxpools);
201 if (err)
202 return err;
203
204 for_each_node_with_cpus(node) {
205 /* some architectures (e.g. SN2) have cpuless nodes */
206 BUG_ON(pidx > maxpools);
207 m->to_pool[node] = pidx;
208 m->pool_to[pidx] = node;
209 pidx++;
210 }
211 /* nodes brought online later all get mapped to pool0, sorry */
212
213 return pidx;
214}
215
216
217/*
218 * Add a reference to the global map of cpus to pools (and
219 * vice versa). Initialise the map if we're the first user.
220 * Returns the number of pools.
221 */
222unsigned int
223svc_pool_map_get(void)
224{
225 struct svc_pool_map *m = &svc_pool_map;
226 int npools = -1;
227
228 mutex_lock(&svc_pool_map_mutex);
229
230 if (m->count++) {
231 mutex_unlock(&svc_pool_map_mutex);
232 return m->npools;
233 }
234
235 if (m->mode == SVC_POOL_AUTO)
236 m->mode = svc_pool_map_choose_mode();
237
238 switch (m->mode) {
239 case SVC_POOL_PERCPU:
240 npools = svc_pool_map_init_percpu(m);
241 break;
242 case SVC_POOL_PERNODE:
243 npools = svc_pool_map_init_pernode(m);
244 break;
245 }
246
247 if (npools < 0) {
248 /* default, or memory allocation failure */
249 npools = 1;
250 m->mode = SVC_POOL_GLOBAL;
251 }
252 m->npools = npools;
253
254 mutex_unlock(&svc_pool_map_mutex);
255 return m->npools;
256}
257EXPORT_SYMBOL_GPL(svc_pool_map_get);
258
259/*
260 * Drop a reference to the global map of cpus to pools.
261 * When the last reference is dropped, the map data is
262 * freed; this allows the sysadmin to change the pool
263 * mode using the pool_mode module option without
264 * rebooting or re-loading sunrpc.ko.
265 */
266void
267svc_pool_map_put(void)
268{
269 struct svc_pool_map *m = &svc_pool_map;
270
271 mutex_lock(&svc_pool_map_mutex);
272
273 if (!--m->count) {
274 kfree(m->to_pool);
275 m->to_pool = NULL;
276 kfree(m->pool_to);
277 m->pool_to = NULL;
278 m->npools = 0;
279 }
280
281 mutex_unlock(&svc_pool_map_mutex);
282}
283EXPORT_SYMBOL_GPL(svc_pool_map_put);
284
285static int svc_pool_map_get_node(unsigned int pidx)
286{
287 const struct svc_pool_map *m = &svc_pool_map;
288
289 if (m->count) {
290 if (m->mode == SVC_POOL_PERCPU)
291 return cpu_to_node(m->pool_to[pidx]);
292 if (m->mode == SVC_POOL_PERNODE)
293 return m->pool_to[pidx];
294 }
295 return NUMA_NO_NODE;
296}
297/*
298 * Set the given thread's cpus_allowed mask so that it
299 * will only run on cpus in the given pool.
300 */
301static inline void
302svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
303{
304 struct svc_pool_map *m = &svc_pool_map;
305 unsigned int node = m->pool_to[pidx];
306
307 /*
308 * The caller checks for sv_nrpools > 1, which
309 * implies that we've been initialized.
310 */
311 WARN_ON_ONCE(m->count == 0);
312 if (m->count == 0)
313 return;
314
315 switch (m->mode) {
316 case SVC_POOL_PERCPU:
317 {
318 set_cpus_allowed_ptr(task, cpumask_of(node));
319 break;
320 }
321 case SVC_POOL_PERNODE:
322 {
323 set_cpus_allowed_ptr(task, cpumask_of_node(node));
324 break;
325 }
326 }
327}
328
329/*
330 * Use the mapping mode to choose a pool for a given CPU.
331 * Used when enqueueing an incoming RPC. Always returns
332 * a non-NULL pool pointer.
333 */
334struct svc_pool *
335svc_pool_for_cpu(struct svc_serv *serv, int cpu)
336{
337 struct svc_pool_map *m = &svc_pool_map;
338 unsigned int pidx = 0;
339
340 /*
341 * An uninitialised map happens in a pure client when
342 * lockd is brought up, so silently treat it the
343 * same as SVC_POOL_GLOBAL.
344 */
345 if (svc_serv_is_pooled(serv)) {
346 switch (m->mode) {
347 case SVC_POOL_PERCPU:
348 pidx = m->to_pool[cpu];
349 break;
350 case SVC_POOL_PERNODE:
351 pidx = m->to_pool[cpu_to_node(cpu)];
352 break;
353 }
354 }
355 return &serv->sv_pools[pidx % serv->sv_nrpools];
356}
357
358int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
359{
360 int err;
361
362 err = rpcb_create_local(net);
363 if (err)
364 return err;
365
366 /* Remove any stale portmap registrations */
367 svc_unregister(serv, net);
368 return 0;
369}
370EXPORT_SYMBOL_GPL(svc_rpcb_setup);
371
372void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
373{
374 svc_unregister(serv, net);
375 rpcb_put_local(net);
376}
377EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
378
379static int svc_uses_rpcbind(struct svc_serv *serv)
380{
381 struct svc_program *progp;
382 unsigned int i;
383
384 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
385 for (i = 0; i < progp->pg_nvers; i++) {
386 if (progp->pg_vers[i] == NULL)
387 continue;
388 if (!progp->pg_vers[i]->vs_hidden)
389 return 1;
390 }
391 }
392
393 return 0;
394}
395
396int svc_bind(struct svc_serv *serv, struct net *net)
397{
398 if (!svc_uses_rpcbind(serv))
399 return 0;
400 return svc_rpcb_setup(serv, net);
401}
402EXPORT_SYMBOL_GPL(svc_bind);
403
404#if defined(CONFIG_SUNRPC_BACKCHANNEL)
405static void
406__svc_init_bc(struct svc_serv *serv)
407{
408 INIT_LIST_HEAD(&serv->sv_cb_list);
409 spin_lock_init(&serv->sv_cb_lock);
410 init_waitqueue_head(&serv->sv_cb_waitq);
411}
412#else
413static void
414__svc_init_bc(struct svc_serv *serv)
415{
416}
417#endif
418
419/*
420 * Create an RPC service
421 */
422static struct svc_serv *
423__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
424 const struct svc_serv_ops *ops)
425{
426 struct svc_serv *serv;
427 unsigned int vers;
428 unsigned int xdrsize;
429 unsigned int i;
430
431 if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
432 return NULL;
433 serv->sv_name = prog->pg_name;
434 serv->sv_program = prog;
435 serv->sv_nrthreads = 1;
436 serv->sv_stats = prog->pg_stats;
437 if (bufsize > RPCSVC_MAXPAYLOAD)
438 bufsize = RPCSVC_MAXPAYLOAD;
439 serv->sv_max_payload = bufsize? bufsize : 4096;
440 serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
441 serv->sv_ops = ops;
442 xdrsize = 0;
443 while (prog) {
444 prog->pg_lovers = prog->pg_nvers-1;
445 for (vers=0; vers<prog->pg_nvers ; vers++)
446 if (prog->pg_vers[vers]) {
447 prog->pg_hivers = vers;
448 if (prog->pg_lovers > vers)
449 prog->pg_lovers = vers;
450 if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
451 xdrsize = prog->pg_vers[vers]->vs_xdrsize;
452 }
453 prog = prog->pg_next;
454 }
455 serv->sv_xdrsize = xdrsize;
456 INIT_LIST_HEAD(&serv->sv_tempsocks);
457 INIT_LIST_HEAD(&serv->sv_permsocks);
458 timer_setup(&serv->sv_temptimer, NULL, 0);
459 spin_lock_init(&serv->sv_lock);
460
461 __svc_init_bc(serv);
462
463 serv->sv_nrpools = npools;
464 serv->sv_pools =
465 kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
466 GFP_KERNEL);
467 if (!serv->sv_pools) {
468 kfree(serv);
469 return NULL;
470 }
471
472 for (i = 0; i < serv->sv_nrpools; i++) {
473 struct svc_pool *pool = &serv->sv_pools[i];
474
475 dprintk("svc: initialising pool %u for %s\n",
476 i, serv->sv_name);
477
478 pool->sp_id = i;
479 INIT_LIST_HEAD(&pool->sp_sockets);
480 INIT_LIST_HEAD(&pool->sp_all_threads);
481 spin_lock_init(&pool->sp_lock);
482 }
483
484 return serv;
485}
486
487struct svc_serv *
488svc_create(struct svc_program *prog, unsigned int bufsize,
489 const struct svc_serv_ops *ops)
490{
491 return __svc_create(prog, bufsize, /*npools*/1, ops);
492}
493EXPORT_SYMBOL_GPL(svc_create);
494
495struct svc_serv *
496svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
497 const struct svc_serv_ops *ops)
498{
499 struct svc_serv *serv;
500 unsigned int npools = svc_pool_map_get();
501
502 serv = __svc_create(prog, bufsize, npools, ops);
503 if (!serv)
504 goto out_err;
505 return serv;
506out_err:
507 svc_pool_map_put();
508 return NULL;
509}
510EXPORT_SYMBOL_GPL(svc_create_pooled);
511
512void svc_shutdown_net(struct svc_serv *serv, struct net *net)
513{
514 svc_close_net(serv, net);
515
516 if (serv->sv_ops->svo_shutdown)
517 serv->sv_ops->svo_shutdown(serv, net);
518}
519EXPORT_SYMBOL_GPL(svc_shutdown_net);
520
521/*
522 * Destroy an RPC service. Should be called with appropriate locking to
523 * protect the sv_nrthreads, sv_permsocks and sv_tempsocks.
524 */
525void
526svc_destroy(struct svc_serv *serv)
527{
528 dprintk("svc: svc_destroy(%s, %d)\n",
529 serv->sv_program->pg_name,
530 serv->sv_nrthreads);
531
532 if (serv->sv_nrthreads) {
533 if (--(serv->sv_nrthreads) != 0) {
534 svc_sock_update_bufs(serv);
535 return;
536 }
537 } else
538 printk("svc_destroy: no threads for serv=%p!\n", serv);
539
540 del_timer_sync(&serv->sv_temptimer);
541
542 /*
543 * The last user is gone and thus all sockets have to be destroyed to
544 * the point. Check this.
545 */
546 BUG_ON(!list_empty(&serv->sv_permsocks));
547 BUG_ON(!list_empty(&serv->sv_tempsocks));
548
549 cache_clean_deferred(serv);
550
551 if (svc_serv_is_pooled(serv))
552 svc_pool_map_put();
553
554 kfree(serv->sv_pools);
555 kfree(serv);
556}
557EXPORT_SYMBOL_GPL(svc_destroy);
558
559/*
560 * Allocate an RPC server's buffer space.
561 * We allocate pages and place them in rq_argpages.
562 */
563static int
564svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
565{
566 unsigned int pages, arghi;
567
568 /* bc_xprt uses fore channel allocated buffers */
569 if (svc_is_backchannel(rqstp))
570 return 1;
571
572 pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
573 * We assume one is at most one page
574 */
575 arghi = 0;
576 WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
577 if (pages > RPCSVC_MAXPAGES)
578 pages = RPCSVC_MAXPAGES;
579 while (pages) {
580 struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
581 if (!p)
582 break;
583 rqstp->rq_pages[arghi++] = p;
584 pages--;
585 }
586 return pages == 0;
587}
588
589/*
590 * Release an RPC server buffer
591 */
592static void
593svc_release_buffer(struct svc_rqst *rqstp)
594{
595 unsigned int i;
596
597 for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
598 if (rqstp->rq_pages[i])
599 put_page(rqstp->rq_pages[i]);
600}
601
602struct svc_rqst *
603svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
604{
605 struct svc_rqst *rqstp;
606
607 rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
608 if (!rqstp)
609 return rqstp;
610
611 __set_bit(RQ_BUSY, &rqstp->rq_flags);
612 spin_lock_init(&rqstp->rq_lock);
613 rqstp->rq_server = serv;
614 rqstp->rq_pool = pool;
615
616 rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
617 if (!rqstp->rq_argp)
618 goto out_enomem;
619
620 rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
621 if (!rqstp->rq_resp)
622 goto out_enomem;
623
624 if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
625 goto out_enomem;
626
627 return rqstp;
628out_enomem:
629 svc_rqst_free(rqstp);
630 return NULL;
631}
632EXPORT_SYMBOL_GPL(svc_rqst_alloc);
633
634struct svc_rqst *
635svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
636{
637 struct svc_rqst *rqstp;
638
639 rqstp = svc_rqst_alloc(serv, pool, node);
640 if (!rqstp)
641 return ERR_PTR(-ENOMEM);
642
643 serv->sv_nrthreads++;
644 spin_lock_bh(&pool->sp_lock);
645 pool->sp_nrthreads++;
646 list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
647 spin_unlock_bh(&pool->sp_lock);
648 return rqstp;
649}
650EXPORT_SYMBOL_GPL(svc_prepare_thread);
651
652/*
653 * Choose a pool in which to create a new thread, for svc_set_num_threads
654 */
655static inline struct svc_pool *
656choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
657{
658 if (pool != NULL)
659 return pool;
660
661 return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
662}
663
664/*
665 * Choose a thread to kill, for svc_set_num_threads
666 */
667static inline struct task_struct *
668choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
669{
670 unsigned int i;
671 struct task_struct *task = NULL;
672
673 if (pool != NULL) {
674 spin_lock_bh(&pool->sp_lock);
675 } else {
676 /* choose a pool in round-robin fashion */
677 for (i = 0; i < serv->sv_nrpools; i++) {
678 pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
679 spin_lock_bh(&pool->sp_lock);
680 if (!list_empty(&pool->sp_all_threads))
681 goto found_pool;
682 spin_unlock_bh(&pool->sp_lock);
683 }
684 return NULL;
685 }
686
687found_pool:
688 if (!list_empty(&pool->sp_all_threads)) {
689 struct svc_rqst *rqstp;
690
691 /*
692 * Remove from the pool->sp_all_threads list
693 * so we don't try to kill it again.
694 */
695 rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
696 set_bit(RQ_VICTIM, &rqstp->rq_flags);
697 list_del_rcu(&rqstp->rq_all);
698 task = rqstp->rq_task;
699 }
700 spin_unlock_bh(&pool->sp_lock);
701
702 return task;
703}
704
705/* create new threads */
706static int
707svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
708{
709 struct svc_rqst *rqstp;
710 struct task_struct *task;
711 struct svc_pool *chosen_pool;
712 unsigned int state = serv->sv_nrthreads-1;
713 int node;
714
715 do {
716 nrservs--;
717 chosen_pool = choose_pool(serv, pool, &state);
718
719 node = svc_pool_map_get_node(chosen_pool->sp_id);
720 rqstp = svc_prepare_thread(serv, chosen_pool, node);
721 if (IS_ERR(rqstp))
722 return PTR_ERR(rqstp);
723
724 __module_get(serv->sv_ops->svo_module);
725 task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp,
726 node, "%s", serv->sv_name);
727 if (IS_ERR(task)) {
728 module_put(serv->sv_ops->svo_module);
729 svc_exit_thread(rqstp);
730 return PTR_ERR(task);
731 }
732
733 rqstp->rq_task = task;
734 if (serv->sv_nrpools > 1)
735 svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
736
737 svc_sock_update_bufs(serv);
738 wake_up_process(task);
739 } while (nrservs > 0);
740
741 return 0;
742}
743
744
745/* destroy old threads */
746static int
747svc_signal_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
748{
749 struct task_struct *task;
750 unsigned int state = serv->sv_nrthreads-1;
751
752 /* destroy old threads */
753 do {
754 task = choose_victim(serv, pool, &state);
755 if (task == NULL)
756 break;
757 send_sig(SIGINT, task, 1);
758 nrservs++;
759 } while (nrservs < 0);
760
761 return 0;
762}
763
764/*
765 * Create or destroy enough new threads to make the number
766 * of threads the given number. If `pool' is non-NULL, applies
767 * only to threads in that pool, otherwise round-robins between
768 * all pools. Caller must ensure that mutual exclusion between this and
769 * server startup or shutdown.
770 *
771 * Destroying threads relies on the service threads filling in
772 * rqstp->rq_task, which only the nfs ones do. Assumes the serv
773 * has been created using svc_create_pooled().
774 *
775 * Based on code that used to be in nfsd_svc() but tweaked
776 * to be pool-aware.
777 */
778int
779svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
780{
781 if (pool == NULL) {
782 /* The -1 assumes caller has done a svc_get() */
783 nrservs -= (serv->sv_nrthreads-1);
784 } else {
785 spin_lock_bh(&pool->sp_lock);
786 nrservs -= pool->sp_nrthreads;
787 spin_unlock_bh(&pool->sp_lock);
788 }
789
790 if (nrservs > 0)
791 return svc_start_kthreads(serv, pool, nrservs);
792 if (nrservs < 0)
793 return svc_signal_kthreads(serv, pool, nrservs);
794 return 0;
795}
796EXPORT_SYMBOL_GPL(svc_set_num_threads);
797
798/* destroy old threads */
799static int
800svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
801{
802 struct task_struct *task;
803 unsigned int state = serv->sv_nrthreads-1;
804
805 /* destroy old threads */
806 do {
807 task = choose_victim(serv, pool, &state);
808 if (task == NULL)
809 break;
810 kthread_stop(task);
811 nrservs++;
812 } while (nrservs < 0);
813 return 0;
814}
815
816int
817svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
818{
819 if (pool == NULL) {
820 /* The -1 assumes caller has done a svc_get() */
821 nrservs -= (serv->sv_nrthreads-1);
822 } else {
823 spin_lock_bh(&pool->sp_lock);
824 nrservs -= pool->sp_nrthreads;
825 spin_unlock_bh(&pool->sp_lock);
826 }
827
828 if (nrservs > 0)
829 return svc_start_kthreads(serv, pool, nrservs);
830 if (nrservs < 0)
831 return svc_stop_kthreads(serv, pool, nrservs);
832 return 0;
833}
834EXPORT_SYMBOL_GPL(svc_set_num_threads_sync);
835
836/*
837 * Called from a server thread as it's exiting. Caller must hold the "service
838 * mutex" for the service.
839 */
840void
841svc_rqst_free(struct svc_rqst *rqstp)
842{
843 svc_release_buffer(rqstp);
844 kfree(rqstp->rq_resp);
845 kfree(rqstp->rq_argp);
846 kfree(rqstp->rq_auth_data);
847 kfree_rcu(rqstp, rq_rcu_head);
848}
849EXPORT_SYMBOL_GPL(svc_rqst_free);
850
851void
852svc_exit_thread(struct svc_rqst *rqstp)
853{
854 struct svc_serv *serv = rqstp->rq_server;
855 struct svc_pool *pool = rqstp->rq_pool;
856
857 spin_lock_bh(&pool->sp_lock);
858 pool->sp_nrthreads--;
859 if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
860 list_del_rcu(&rqstp->rq_all);
861 spin_unlock_bh(&pool->sp_lock);
862
863 svc_rqst_free(rqstp);
864
865 /* Release the server */
866 if (serv)
867 svc_destroy(serv);
868}
869EXPORT_SYMBOL_GPL(svc_exit_thread);
870
871/*
872 * Register an "inet" protocol family netid with the local
873 * rpcbind daemon via an rpcbind v4 SET request.
874 *
875 * No netconfig infrastructure is available in the kernel, so
876 * we map IP_ protocol numbers to netids by hand.
877 *
878 * Returns zero on success; a negative errno value is returned
879 * if any error occurs.
880 */
881static int __svc_rpcb_register4(struct net *net, const u32 program,
882 const u32 version,
883 const unsigned short protocol,
884 const unsigned short port)
885{
886 const struct sockaddr_in sin = {
887 .sin_family = AF_INET,
888 .sin_addr.s_addr = htonl(INADDR_ANY),
889 .sin_port = htons(port),
890 };
891 const char *netid;
892 int error;
893
894 switch (protocol) {
895 case IPPROTO_UDP:
896 netid = RPCBIND_NETID_UDP;
897 break;
898 case IPPROTO_TCP:
899 netid = RPCBIND_NETID_TCP;
900 break;
901 default:
902 return -ENOPROTOOPT;
903 }
904
905 error = rpcb_v4_register(net, program, version,
906 (const struct sockaddr *)&sin, netid);
907
908 /*
909 * User space didn't support rpcbind v4, so retry this
910 * registration request with the legacy rpcbind v2 protocol.
911 */
912 if (error == -EPROTONOSUPPORT)
913 error = rpcb_register(net, program, version, protocol, port);
914
915 return error;
916}
917
918#if IS_ENABLED(CONFIG_IPV6)
919/*
920 * Register an "inet6" protocol family netid with the local
921 * rpcbind daemon via an rpcbind v4 SET request.
922 *
923 * No netconfig infrastructure is available in the kernel, so
924 * we map IP_ protocol numbers to netids by hand.
925 *
926 * Returns zero on success; a negative errno value is returned
927 * if any error occurs.
928 */
929static int __svc_rpcb_register6(struct net *net, const u32 program,
930 const u32 version,
931 const unsigned short protocol,
932 const unsigned short port)
933{
934 const struct sockaddr_in6 sin6 = {
935 .sin6_family = AF_INET6,
936 .sin6_addr = IN6ADDR_ANY_INIT,
937 .sin6_port = htons(port),
938 };
939 const char *netid;
940 int error;
941
942 switch (protocol) {
943 case IPPROTO_UDP:
944 netid = RPCBIND_NETID_UDP6;
945 break;
946 case IPPROTO_TCP:
947 netid = RPCBIND_NETID_TCP6;
948 break;
949 default:
950 return -ENOPROTOOPT;
951 }
952
953 error = rpcb_v4_register(net, program, version,
954 (const struct sockaddr *)&sin6, netid);
955
956 /*
957 * User space didn't support rpcbind version 4, so we won't
958 * use a PF_INET6 listener.
959 */
960 if (error == -EPROTONOSUPPORT)
961 error = -EAFNOSUPPORT;
962
963 return error;
964}
965#endif /* IS_ENABLED(CONFIG_IPV6) */
966
967/*
968 * Register a kernel RPC service via rpcbind version 4.
969 *
970 * Returns zero on success; a negative errno value is returned
971 * if any error occurs.
972 */
973static int __svc_register(struct net *net, const char *progname,
974 const u32 program, const u32 version,
975 const int family,
976 const unsigned short protocol,
977 const unsigned short port)
978{
979 int error = -EAFNOSUPPORT;
980
981 switch (family) {
982 case PF_INET:
983 error = __svc_rpcb_register4(net, program, version,
984 protocol, port);
985 break;
986#if IS_ENABLED(CONFIG_IPV6)
987 case PF_INET6:
988 error = __svc_rpcb_register6(net, program, version,
989 protocol, port);
990#endif
991 }
992
993 return error;
994}
995
996/**
997 * svc_register - register an RPC service with the local portmapper
998 * @serv: svc_serv struct for the service to register
999 * @net: net namespace for the service to register
1000 * @family: protocol family of service's listener socket
1001 * @proto: transport protocol number to advertise
1002 * @port: port to advertise
1003 *
1004 * Service is registered for any address in the passed-in protocol family
1005 */
1006int svc_register(const struct svc_serv *serv, struct net *net,
1007 const int family, const unsigned short proto,
1008 const unsigned short port)
1009{
1010 struct svc_program *progp;
1011 const struct svc_version *vers;
1012 unsigned int i;
1013 int error = 0;
1014
1015 WARN_ON_ONCE(proto == 0 && port == 0);
1016 if (proto == 0 && port == 0)
1017 return -EINVAL;
1018
1019 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1020 for (i = 0; i < progp->pg_nvers; i++) {
1021 vers = progp->pg_vers[i];
1022 if (vers == NULL)
1023 continue;
1024
1025 dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
1026 progp->pg_name,
1027 i,
1028 proto == IPPROTO_UDP? "udp" : "tcp",
1029 port,
1030 family,
1031 vers->vs_hidden ?
1032 " (but not telling portmap)" : "");
1033
1034 if (vers->vs_hidden)
1035 continue;
1036
1037 /*
1038 * Don't register a UDP port if we need congestion
1039 * control.
1040 */
1041 if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
1042 continue;
1043
1044 error = __svc_register(net, progp->pg_name, progp->pg_prog,
1045 i, family, proto, port);
1046
1047 if (vers->vs_rpcb_optnl) {
1048 error = 0;
1049 continue;
1050 }
1051
1052 if (error < 0) {
1053 printk(KERN_WARNING "svc: failed to register "
1054 "%sv%u RPC service (errno %d).\n",
1055 progp->pg_name, i, -error);
1056 break;
1057 }
1058 }
1059 }
1060
1061 return error;
1062}
1063
1064/*
1065 * If user space is running rpcbind, it should take the v4 UNSET
1066 * and clear everything for this [program, version]. If user space
1067 * is running portmap, it will reject the v4 UNSET, but won't have
1068 * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient
1069 * in this case to clear all existing entries for [program, version].
1070 */
1071static void __svc_unregister(struct net *net, const u32 program, const u32 version,
1072 const char *progname)
1073{
1074 int error;
1075
1076 error = rpcb_v4_register(net, program, version, NULL, "");
1077
1078 /*
1079 * User space didn't support rpcbind v4, so retry this
1080 * request with the legacy rpcbind v2 protocol.
1081 */
1082 if (error == -EPROTONOSUPPORT)
1083 error = rpcb_register(net, program, version, 0, 0);
1084
1085 dprintk("svc: %s(%sv%u), error %d\n",
1086 __func__, progname, version, error);
1087}
1088
1089/*
1090 * All netids, bind addresses and ports registered for [program, version]
1091 * are removed from the local rpcbind database (if the service is not
1092 * hidden) to make way for a new instance of the service.
1093 *
1094 * The result of unregistration is reported via dprintk for those who want
1095 * verification of the result, but is otherwise not important.
1096 */
1097static void svc_unregister(const struct svc_serv *serv, struct net *net)
1098{
1099 struct svc_program *progp;
1100 unsigned long flags;
1101 unsigned int i;
1102
1103 clear_thread_flag(TIF_SIGPENDING);
1104
1105 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1106 for (i = 0; i < progp->pg_nvers; i++) {
1107 if (progp->pg_vers[i] == NULL)
1108 continue;
1109 if (progp->pg_vers[i]->vs_hidden)
1110 continue;
1111
1112 dprintk("svc: attempting to unregister %sv%u\n",
1113 progp->pg_name, i);
1114 __svc_unregister(net, progp->pg_prog, i, progp->pg_name);
1115 }
1116 }
1117
1118 spin_lock_irqsave(¤t->sighand->siglock, flags);
1119 recalc_sigpending();
1120 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
1121}
1122
1123/*
1124 * dprintk the given error with the address of the client that caused it.
1125 */
1126#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1127static __printf(2, 3)
1128void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
1129{
1130 struct va_format vaf;
1131 va_list args;
1132 char buf[RPC_MAX_ADDRBUFLEN];
1133
1134 va_start(args, fmt);
1135
1136 vaf.fmt = fmt;
1137 vaf.va = &args;
1138
1139 dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
1140
1141 va_end(args);
1142}
1143#else
1144static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
1145#endif
1146
1147/*
1148 * Common routine for processing the RPC request.
1149 */
1150static int
1151svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
1152{
1153 struct svc_program *progp;
1154 const struct svc_version *versp = NULL; /* compiler food */
1155 const struct svc_procedure *procp = NULL;
1156 struct svc_serv *serv = rqstp->rq_server;
1157 __be32 *statp;
1158 u32 prog, vers, proc;
1159 __be32 auth_stat, rpc_stat;
1160 int auth_res;
1161 __be32 *reply_statp;
1162
1163 rpc_stat = rpc_success;
1164
1165 if (argv->iov_len < 6*4)
1166 goto err_short_len;
1167
1168 /* Will be turned off by GSS integrity and privacy services */
1169 set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
1170 /* Will be turned off only when NFSv4 Sessions are used */
1171 set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
1172 clear_bit(RQ_DROPME, &rqstp->rq_flags);
1173
1174 /* Setup reply header */
1175 rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
1176
1177 svc_putu32(resv, rqstp->rq_xid);
1178
1179 vers = svc_getnl(argv);
1180
1181 /* First words of reply: */
1182 svc_putnl(resv, 1); /* REPLY */
1183
1184 if (vers != 2) /* RPC version number */
1185 goto err_bad_rpc;
1186
1187 /* Save position in case we later decide to reject: */
1188 reply_statp = resv->iov_base + resv->iov_len;
1189
1190 svc_putnl(resv, 0); /* ACCEPT */
1191
1192 rqstp->rq_prog = prog = svc_getnl(argv); /* program number */
1193 rqstp->rq_vers = vers = svc_getnl(argv); /* version number */
1194 rqstp->rq_proc = proc = svc_getnl(argv); /* procedure number */
1195
1196 for (progp = serv->sv_program; progp; progp = progp->pg_next)
1197 if (prog == progp->pg_prog)
1198 break;
1199
1200 /*
1201 * Decode auth data, and add verifier to reply buffer.
1202 * We do this before anything else in order to get a decent
1203 * auth verifier.
1204 */
1205 auth_res = svc_authenticate(rqstp, &auth_stat);
1206 /* Also give the program a chance to reject this call: */
1207 if (auth_res == SVC_OK && progp) {
1208 auth_stat = rpc_autherr_badcred;
1209 auth_res = progp->pg_authenticate(rqstp);
1210 }
1211 switch (auth_res) {
1212 case SVC_OK:
1213 break;
1214 case SVC_GARBAGE:
1215 goto err_garbage;
1216 case SVC_SYSERR:
1217 rpc_stat = rpc_system_err;
1218 goto err_bad;
1219 case SVC_DENIED:
1220 goto err_bad_auth;
1221 case SVC_CLOSE:
1222 goto close;
1223 case SVC_DROP:
1224 goto dropit;
1225 case SVC_COMPLETE:
1226 goto sendit;
1227 }
1228
1229 if (progp == NULL)
1230 goto err_bad_prog;
1231
1232 if (vers >= progp->pg_nvers ||
1233 !(versp = progp->pg_vers[vers]))
1234 goto err_bad_vers;
1235
1236 /*
1237 * Some protocol versions (namely NFSv4) require some form of
1238 * congestion control. (See RFC 7530 section 3.1 paragraph 2)
1239 * In other words, UDP is not allowed. We mark those when setting
1240 * up the svc_xprt, and verify that here.
1241 *
1242 * The spec is not very clear about what error should be returned
1243 * when someone tries to access a server that is listening on UDP
1244 * for lower versions. RPC_PROG_MISMATCH seems to be the closest
1245 * fit.
1246 */
1247 if (versp->vs_need_cong_ctrl &&
1248 !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
1249 goto err_bad_vers;
1250
1251 procp = versp->vs_proc + proc;
1252 if (proc >= versp->vs_nproc || !procp->pc_func)
1253 goto err_bad_proc;
1254 rqstp->rq_procinfo = procp;
1255
1256 /* Syntactic check complete */
1257 serv->sv_stats->rpccnt++;
1258 trace_svc_process(rqstp, progp->pg_name);
1259
1260 /* Build the reply header. */
1261 statp = resv->iov_base +resv->iov_len;
1262 svc_putnl(resv, RPC_SUCCESS);
1263
1264 /* Bump per-procedure stats counter */
1265 versp->vs_count[proc]++;
1266
1267 /* Initialize storage for argp and resp */
1268 memset(rqstp->rq_argp, 0, procp->pc_argsize);
1269 memset(rqstp->rq_resp, 0, procp->pc_ressize);
1270
1271 /* un-reserve some of the out-queue now that we have a
1272 * better idea of reply size
1273 */
1274 if (procp->pc_xdrressize)
1275 svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1276
1277 /* Call the function that processes the request. */
1278 if (!versp->vs_dispatch) {
1279 /*
1280 * Decode arguments
1281 * XXX: why do we ignore the return value?
1282 */
1283 if (procp->pc_decode &&
1284 !procp->pc_decode(rqstp, argv->iov_base))
1285 goto err_garbage;
1286
1287 *statp = procp->pc_func(rqstp);
1288
1289 /* Encode reply */
1290 if (*statp == rpc_drop_reply ||
1291 test_bit(RQ_DROPME, &rqstp->rq_flags)) {
1292 if (procp->pc_release)
1293 procp->pc_release(rqstp);
1294 goto dropit;
1295 }
1296 if (*statp == rpc_autherr_badcred) {
1297 if (procp->pc_release)
1298 procp->pc_release(rqstp);
1299 goto err_bad_auth;
1300 }
1301 if (*statp == rpc_success && procp->pc_encode &&
1302 !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) {
1303 dprintk("svc: failed to encode reply\n");
1304 /* serv->sv_stats->rpcsystemerr++; */
1305 *statp = rpc_system_err;
1306 }
1307 } else {
1308 dprintk("svc: calling dispatcher\n");
1309 if (!versp->vs_dispatch(rqstp, statp)) {
1310 /* Release reply info */
1311 if (procp->pc_release)
1312 procp->pc_release(rqstp);
1313 goto dropit;
1314 }
1315 }
1316
1317 /* Check RPC status result */
1318 if (*statp != rpc_success)
1319 resv->iov_len = ((void*)statp) - resv->iov_base + 4;
1320
1321 /* Release reply info */
1322 if (procp->pc_release)
1323 procp->pc_release(rqstp);
1324
1325 if (procp->pc_encode == NULL)
1326 goto dropit;
1327
1328 sendit:
1329 if (svc_authorise(rqstp))
1330 goto close;
1331 return 1; /* Caller can now send it */
1332
1333 dropit:
1334 svc_authorise(rqstp); /* doesn't hurt to call this twice */
1335 dprintk("svc: svc_process dropit\n");
1336 return 0;
1337
1338 close:
1339 if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1340 svc_close_xprt(rqstp->rq_xprt);
1341 dprintk("svc: svc_process close\n");
1342 return 0;
1343
1344err_short_len:
1345 svc_printk(rqstp, "short len %zd, dropping request\n",
1346 argv->iov_len);
1347 goto close;
1348
1349err_bad_rpc:
1350 serv->sv_stats->rpcbadfmt++;
1351 svc_putnl(resv, 1); /* REJECT */
1352 svc_putnl(resv, 0); /* RPC_MISMATCH */
1353 svc_putnl(resv, 2); /* Only RPCv2 supported */
1354 svc_putnl(resv, 2);
1355 goto sendit;
1356
1357err_bad_auth:
1358 dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
1359 serv->sv_stats->rpcbadauth++;
1360 /* Restore write pointer to location of accept status: */
1361 xdr_ressize_check(rqstp, reply_statp);
1362 svc_putnl(resv, 1); /* REJECT */
1363 svc_putnl(resv, 1); /* AUTH_ERROR */
1364 svc_putnl(resv, ntohl(auth_stat)); /* status */
1365 goto sendit;
1366
1367err_bad_prog:
1368 dprintk("svc: unknown program %d\n", prog);
1369 serv->sv_stats->rpcbadfmt++;
1370 svc_putnl(resv, RPC_PROG_UNAVAIL);
1371 goto sendit;
1372
1373err_bad_vers:
1374 svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1375 vers, prog, progp->pg_name);
1376
1377 serv->sv_stats->rpcbadfmt++;
1378 svc_putnl(resv, RPC_PROG_MISMATCH);
1379 svc_putnl(resv, progp->pg_lovers);
1380 svc_putnl(resv, progp->pg_hivers);
1381 goto sendit;
1382
1383err_bad_proc:
1384 svc_printk(rqstp, "unknown procedure (%d)\n", proc);
1385
1386 serv->sv_stats->rpcbadfmt++;
1387 svc_putnl(resv, RPC_PROC_UNAVAIL);
1388 goto sendit;
1389
1390err_garbage:
1391 svc_printk(rqstp, "failed to decode args\n");
1392
1393 rpc_stat = rpc_garbage_args;
1394err_bad:
1395 serv->sv_stats->rpcbadfmt++;
1396 svc_putnl(resv, ntohl(rpc_stat));
1397 goto sendit;
1398}
1399
1400/*
1401 * Process the RPC request.
1402 */
1403int
1404svc_process(struct svc_rqst *rqstp)
1405{
1406 struct kvec *argv = &rqstp->rq_arg.head[0];
1407 struct kvec *resv = &rqstp->rq_res.head[0];
1408 struct svc_serv *serv = rqstp->rq_server;
1409 u32 dir;
1410
1411 /*
1412 * Setup response xdr_buf.
1413 * Initially it has just one page
1414 */
1415 rqstp->rq_next_page = &rqstp->rq_respages[1];
1416 resv->iov_base = page_address(rqstp->rq_respages[0]);
1417 resv->iov_len = 0;
1418 rqstp->rq_res.pages = rqstp->rq_respages + 1;
1419 rqstp->rq_res.len = 0;
1420 rqstp->rq_res.page_base = 0;
1421 rqstp->rq_res.page_len = 0;
1422 rqstp->rq_res.buflen = PAGE_SIZE;
1423 rqstp->rq_res.tail[0].iov_base = NULL;
1424 rqstp->rq_res.tail[0].iov_len = 0;
1425
1426 dir = svc_getnl(argv);
1427 if (dir != 0) {
1428 /* direction != CALL */
1429 svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
1430 serv->sv_stats->rpcbadfmt++;
1431 goto out_drop;
1432 }
1433
1434 /* Returns 1 for send, 0 for drop */
1435 if (likely(svc_process_common(rqstp, argv, resv)))
1436 return svc_send(rqstp);
1437
1438out_drop:
1439 svc_drop(rqstp);
1440 return 0;
1441}
1442EXPORT_SYMBOL_GPL(svc_process);
1443
1444#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1445/*
1446 * Process a backchannel RPC request that arrived over an existing
1447 * outbound connection
1448 */
1449int
1450bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
1451 struct svc_rqst *rqstp)
1452{
1453 struct kvec *argv = &rqstp->rq_arg.head[0];
1454 struct kvec *resv = &rqstp->rq_res.head[0];
1455 struct rpc_task *task;
1456 int proc_error;
1457 int error;
1458
1459 dprintk("svc: %s(%p)\n", __func__, req);
1460
1461 /* Build the svc_rqst used by the common processing routine */
1462 rqstp->rq_xprt = serv->sv_bc_xprt;
1463 rqstp->rq_xid = req->rq_xid;
1464 rqstp->rq_prot = req->rq_xprt->prot;
1465 rqstp->rq_server = serv;
1466
1467 rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1468 memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1469 memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1470 memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1471
1472 /* Adjust the argument buffer length */
1473 rqstp->rq_arg.len = req->rq_private_buf.len;
1474 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1475 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1476 rqstp->rq_arg.page_len = 0;
1477 } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
1478 rqstp->rq_arg.page_len)
1479 rqstp->rq_arg.page_len = rqstp->rq_arg.len -
1480 rqstp->rq_arg.head[0].iov_len;
1481 else
1482 rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
1483 rqstp->rq_arg.page_len;
1484
1485 /* reset result send buffer "put" position */
1486 resv->iov_len = 0;
1487
1488 /*
1489 * Skip the next two words because they've already been
1490 * processed in the transport
1491 */
1492 svc_getu32(argv); /* XID */
1493 svc_getnl(argv); /* CALLDIR */
1494
1495 /* Parse and execute the bc call */
1496 proc_error = svc_process_common(rqstp, argv, resv);
1497
1498 atomic_inc(&req->rq_xprt->bc_free_slots);
1499 if (!proc_error) {
1500 /* Processing error: drop the request */
1501 xprt_free_bc_request(req);
1502 return 0;
1503 }
1504
1505 /* Finally, send the reply synchronously */
1506 memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
1507 task = rpc_run_bc_task(req);
1508 if (IS_ERR(task)) {
1509 error = PTR_ERR(task);
1510 goto out;
1511 }
1512
1513 WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
1514 error = task->tk_status;
1515 rpc_put_task(task);
1516
1517out:
1518 dprintk("svc: %s(), error=%d\n", __func__, error);
1519 return error;
1520}
1521EXPORT_SYMBOL_GPL(bc_svc_process);
1522#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1523
1524/*
1525 * Return (transport-specific) limit on the rpc payload.
1526 */
1527u32 svc_max_payload(const struct svc_rqst *rqstp)
1528{
1529 u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1530
1531 if (rqstp->rq_server->sv_max_payload < max)
1532 max = rqstp->rq_server->sv_max_payload;
1533 return max;
1534}
1535EXPORT_SYMBOL_GPL(svc_max_payload);
1536
1537/**
1538 * svc_fill_write_vector - Construct data argument for VFS write call
1539 * @rqstp: svc_rqst to operate on
1540 * @first: buffer containing first section of write payload
1541 * @total: total number of bytes of write payload
1542 *
1543 * Returns the number of elements populated in the data argument array.
1544 */
1545unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct kvec *first,
1546 size_t total)
1547{
1548 struct kvec *vec = rqstp->rq_vec;
1549 struct page **pages;
1550 unsigned int i;
1551
1552 /* Some types of transport can present the write payload
1553 * entirely in rq_arg.pages. In this case, @first is empty.
1554 */
1555 i = 0;
1556 if (first->iov_len) {
1557 vec[i].iov_base = first->iov_base;
1558 vec[i].iov_len = min_t(size_t, total, first->iov_len);
1559 total -= vec[i].iov_len;
1560 ++i;
1561 }
1562
1563 WARN_ON_ONCE(rqstp->rq_arg.page_base != 0);
1564 pages = rqstp->rq_arg.pages;
1565 while (total) {
1566 vec[i].iov_base = page_address(*pages);
1567 vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
1568 total -= vec[i].iov_len;
1569 ++i;
1570
1571 ++pages;
1572 }
1573
1574 WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
1575 return i;
1576}
1577EXPORT_SYMBOL_GPL(svc_fill_write_vector);
1578
1579/**
1580 * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
1581 * @rqstp: svc_rqst to operate on
1582 * @first: buffer containing first section of pathname
1583 * @total: total length of the pathname argument
1584 *
1585 * Returns pointer to a NUL-terminated string, or an ERR_PTR. The buffer is
1586 * released automatically when @rqstp is recycled.
1587 */
1588char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
1589 size_t total)
1590{
1591 struct xdr_buf *arg = &rqstp->rq_arg;
1592 struct page **pages;
1593 char *result;
1594
1595 /* VFS API demands a NUL-terminated pathname. This function
1596 * uses a page from @rqstp as the pathname buffer, to enable
1597 * direct placement. Thus the total buffer size is PAGE_SIZE.
1598 * Space in this buffer for NUL-termination requires that we
1599 * cap the size of the returned symlink pathname just a
1600 * little early.
1601 */
1602 if (total > PAGE_SIZE - 1)
1603 return ERR_PTR(-ENAMETOOLONG);
1604
1605 /* Some types of transport can present the pathname entirely
1606 * in rq_arg.pages. If not, then copy the pathname into one
1607 * page.
1608 */
1609 pages = arg->pages;
1610 WARN_ON_ONCE(arg->page_base != 0);
1611 if (first->iov_base == 0) {
1612 result = page_address(*pages);
1613 result[total] = '\0';
1614 } else {
1615 size_t len, remaining;
1616 char *dst;
1617
1618 result = page_address(*(rqstp->rq_next_page++));
1619 dst = result;
1620 remaining = total;
1621
1622 len = min_t(size_t, total, first->iov_len);
1623 memcpy(dst, first->iov_base, len);
1624 dst += len;
1625 remaining -= len;
1626
1627 /* No more than one page left */
1628 if (remaining) {
1629 len = min_t(size_t, remaining, PAGE_SIZE);
1630 memcpy(dst, page_address(*pages), len);
1631 dst += len;
1632 }
1633
1634 *dst = '\0';
1635 }
1636
1637 /* Sanity check: we don't allow the pathname argument to
1638 * contain a NUL byte.
1639 */
1640 if (strlen(result) != total)
1641 return ERR_PTR(-EINVAL);
1642 return result;
1643}
1644EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);
1/*
2 * linux/net/sunrpc/svc.c
3 *
4 * High-level RPC service routines
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 *
8 * Multiple threads pools and NUMAisation
9 * Copyright (c) 2006 Silicon Graphics, Inc.
10 * by Greg Banks <gnb@melbourne.sgi.com>
11 */
12
13#include <linux/linkage.h>
14#include <linux/sched.h>
15#include <linux/errno.h>
16#include <linux/net.h>
17#include <linux/in.h>
18#include <linux/mm.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/kthread.h>
22#include <linux/slab.h>
23
24#include <linux/sunrpc/types.h>
25#include <linux/sunrpc/xdr.h>
26#include <linux/sunrpc/stats.h>
27#include <linux/sunrpc/svcsock.h>
28#include <linux/sunrpc/clnt.h>
29#include <linux/sunrpc/bc_xprt.h>
30
31#define RPCDBG_FACILITY RPCDBG_SVCDSP
32
33static void svc_unregister(const struct svc_serv *serv);
34
35#define svc_serv_is_pooled(serv) ((serv)->sv_function)
36
37/*
38 * Mode for mapping cpus to pools.
39 */
40enum {
41 SVC_POOL_AUTO = -1, /* choose one of the others */
42 SVC_POOL_GLOBAL, /* no mapping, just a single global pool
43 * (legacy & UP mode) */
44 SVC_POOL_PERCPU, /* one pool per cpu */
45 SVC_POOL_PERNODE /* one pool per numa node */
46};
47#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
48
49/*
50 * Structure for mapping cpus to pools and vice versa.
51 * Setup once during sunrpc initialisation.
52 */
53static struct svc_pool_map {
54 int count; /* How many svc_servs use us */
55 int mode; /* Note: int not enum to avoid
56 * warnings about "enumeration value
57 * not handled in switch" */
58 unsigned int npools;
59 unsigned int *pool_to; /* maps pool id to cpu or node */
60 unsigned int *to_pool; /* maps cpu or node to pool id */
61} svc_pool_map = {
62 .count = 0,
63 .mode = SVC_POOL_DEFAULT
64};
65static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
66
67static int
68param_set_pool_mode(const char *val, struct kernel_param *kp)
69{
70 int *ip = (int *)kp->arg;
71 struct svc_pool_map *m = &svc_pool_map;
72 int err;
73
74 mutex_lock(&svc_pool_map_mutex);
75
76 err = -EBUSY;
77 if (m->count)
78 goto out;
79
80 err = 0;
81 if (!strncmp(val, "auto", 4))
82 *ip = SVC_POOL_AUTO;
83 else if (!strncmp(val, "global", 6))
84 *ip = SVC_POOL_GLOBAL;
85 else if (!strncmp(val, "percpu", 6))
86 *ip = SVC_POOL_PERCPU;
87 else if (!strncmp(val, "pernode", 7))
88 *ip = SVC_POOL_PERNODE;
89 else
90 err = -EINVAL;
91
92out:
93 mutex_unlock(&svc_pool_map_mutex);
94 return err;
95}
96
97static int
98param_get_pool_mode(char *buf, struct kernel_param *kp)
99{
100 int *ip = (int *)kp->arg;
101
102 switch (*ip)
103 {
104 case SVC_POOL_AUTO:
105 return strlcpy(buf, "auto", 20);
106 case SVC_POOL_GLOBAL:
107 return strlcpy(buf, "global", 20);
108 case SVC_POOL_PERCPU:
109 return strlcpy(buf, "percpu", 20);
110 case SVC_POOL_PERNODE:
111 return strlcpy(buf, "pernode", 20);
112 default:
113 return sprintf(buf, "%d", *ip);
114 }
115}
116
117module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
118 &svc_pool_map.mode, 0644);
119
120/*
121 * Detect best pool mapping mode heuristically,
122 * according to the machine's topology.
123 */
124static int
125svc_pool_map_choose_mode(void)
126{
127 unsigned int node;
128
129 if (nr_online_nodes > 1) {
130 /*
131 * Actually have multiple NUMA nodes,
132 * so split pools on NUMA node boundaries
133 */
134 return SVC_POOL_PERNODE;
135 }
136
137 node = first_online_node;
138 if (nr_cpus_node(node) > 2) {
139 /*
140 * Non-trivial SMP, or CONFIG_NUMA on
141 * non-NUMA hardware, e.g. with a generic
142 * x86_64 kernel on Xeons. In this case we
143 * want to divide the pools on cpu boundaries.
144 */
145 return SVC_POOL_PERCPU;
146 }
147
148 /* default: one global pool */
149 return SVC_POOL_GLOBAL;
150}
151
152/*
153 * Allocate the to_pool[] and pool_to[] arrays.
154 * Returns 0 on success or an errno.
155 */
156static int
157svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
158{
159 m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
160 if (!m->to_pool)
161 goto fail;
162 m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
163 if (!m->pool_to)
164 goto fail_free;
165
166 return 0;
167
168fail_free:
169 kfree(m->to_pool);
170fail:
171 return -ENOMEM;
172}
173
174/*
175 * Initialise the pool map for SVC_POOL_PERCPU mode.
176 * Returns number of pools or <0 on error.
177 */
178static int
179svc_pool_map_init_percpu(struct svc_pool_map *m)
180{
181 unsigned int maxpools = nr_cpu_ids;
182 unsigned int pidx = 0;
183 unsigned int cpu;
184 int err;
185
186 err = svc_pool_map_alloc_arrays(m, maxpools);
187 if (err)
188 return err;
189
190 for_each_online_cpu(cpu) {
191 BUG_ON(pidx > maxpools);
192 m->to_pool[cpu] = pidx;
193 m->pool_to[pidx] = cpu;
194 pidx++;
195 }
196 /* cpus brought online later all get mapped to pool0, sorry */
197
198 return pidx;
199};
200
201
202/*
203 * Initialise the pool map for SVC_POOL_PERNODE mode.
204 * Returns number of pools or <0 on error.
205 */
206static int
207svc_pool_map_init_pernode(struct svc_pool_map *m)
208{
209 unsigned int maxpools = nr_node_ids;
210 unsigned int pidx = 0;
211 unsigned int node;
212 int err;
213
214 err = svc_pool_map_alloc_arrays(m, maxpools);
215 if (err)
216 return err;
217
218 for_each_node_with_cpus(node) {
219 /* some architectures (e.g. SN2) have cpuless nodes */
220 BUG_ON(pidx > maxpools);
221 m->to_pool[node] = pidx;
222 m->pool_to[pidx] = node;
223 pidx++;
224 }
225 /* nodes brought online later all get mapped to pool0, sorry */
226
227 return pidx;
228}
229
230
231/*
232 * Add a reference to the global map of cpus to pools (and
233 * vice versa). Initialise the map if we're the first user.
234 * Returns the number of pools.
235 */
236static unsigned int
237svc_pool_map_get(void)
238{
239 struct svc_pool_map *m = &svc_pool_map;
240 int npools = -1;
241
242 mutex_lock(&svc_pool_map_mutex);
243
244 if (m->count++) {
245 mutex_unlock(&svc_pool_map_mutex);
246 return m->npools;
247 }
248
249 if (m->mode == SVC_POOL_AUTO)
250 m->mode = svc_pool_map_choose_mode();
251
252 switch (m->mode) {
253 case SVC_POOL_PERCPU:
254 npools = svc_pool_map_init_percpu(m);
255 break;
256 case SVC_POOL_PERNODE:
257 npools = svc_pool_map_init_pernode(m);
258 break;
259 }
260
261 if (npools < 0) {
262 /* default, or memory allocation failure */
263 npools = 1;
264 m->mode = SVC_POOL_GLOBAL;
265 }
266 m->npools = npools;
267
268 mutex_unlock(&svc_pool_map_mutex);
269 return m->npools;
270}
271
272
273/*
274 * Drop a reference to the global map of cpus to pools.
275 * When the last reference is dropped, the map data is
276 * freed; this allows the sysadmin to change the pool
277 * mode using the pool_mode module option without
278 * rebooting or re-loading sunrpc.ko.
279 */
280static void
281svc_pool_map_put(void)
282{
283 struct svc_pool_map *m = &svc_pool_map;
284
285 mutex_lock(&svc_pool_map_mutex);
286
287 if (!--m->count) {
288 m->mode = SVC_POOL_DEFAULT;
289 kfree(m->to_pool);
290 kfree(m->pool_to);
291 m->npools = 0;
292 }
293
294 mutex_unlock(&svc_pool_map_mutex);
295}
296
297
298/*
299 * Set the given thread's cpus_allowed mask so that it
300 * will only run on cpus in the given pool.
301 */
302static inline void
303svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
304{
305 struct svc_pool_map *m = &svc_pool_map;
306 unsigned int node = m->pool_to[pidx];
307
308 /*
309 * The caller checks for sv_nrpools > 1, which
310 * implies that we've been initialized.
311 */
312 BUG_ON(m->count == 0);
313
314 switch (m->mode) {
315 case SVC_POOL_PERCPU:
316 {
317 set_cpus_allowed_ptr(task, cpumask_of(node));
318 break;
319 }
320 case SVC_POOL_PERNODE:
321 {
322 set_cpus_allowed_ptr(task, cpumask_of_node(node));
323 break;
324 }
325 }
326}
327
328/*
329 * Use the mapping mode to choose a pool for a given CPU.
330 * Used when enqueueing an incoming RPC. Always returns
331 * a non-NULL pool pointer.
332 */
333struct svc_pool *
334svc_pool_for_cpu(struct svc_serv *serv, int cpu)
335{
336 struct svc_pool_map *m = &svc_pool_map;
337 unsigned int pidx = 0;
338
339 /*
340 * An uninitialised map happens in a pure client when
341 * lockd is brought up, so silently treat it the
342 * same as SVC_POOL_GLOBAL.
343 */
344 if (svc_serv_is_pooled(serv)) {
345 switch (m->mode) {
346 case SVC_POOL_PERCPU:
347 pidx = m->to_pool[cpu];
348 break;
349 case SVC_POOL_PERNODE:
350 pidx = m->to_pool[cpu_to_node(cpu)];
351 break;
352 }
353 }
354 return &serv->sv_pools[pidx % serv->sv_nrpools];
355}
356
357
358/*
359 * Create an RPC service
360 */
361static struct svc_serv *
362__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
363 void (*shutdown)(struct svc_serv *serv))
364{
365 struct svc_serv *serv;
366 unsigned int vers;
367 unsigned int xdrsize;
368 unsigned int i;
369
370 if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
371 return NULL;
372 serv->sv_name = prog->pg_name;
373 serv->sv_program = prog;
374 serv->sv_nrthreads = 1;
375 serv->sv_stats = prog->pg_stats;
376 if (bufsize > RPCSVC_MAXPAYLOAD)
377 bufsize = RPCSVC_MAXPAYLOAD;
378 serv->sv_max_payload = bufsize? bufsize : 4096;
379 serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
380 serv->sv_shutdown = shutdown;
381 xdrsize = 0;
382 while (prog) {
383 prog->pg_lovers = prog->pg_nvers-1;
384 for (vers=0; vers<prog->pg_nvers ; vers++)
385 if (prog->pg_vers[vers]) {
386 prog->pg_hivers = vers;
387 if (prog->pg_lovers > vers)
388 prog->pg_lovers = vers;
389 if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
390 xdrsize = prog->pg_vers[vers]->vs_xdrsize;
391 }
392 prog = prog->pg_next;
393 }
394 serv->sv_xdrsize = xdrsize;
395 INIT_LIST_HEAD(&serv->sv_tempsocks);
396 INIT_LIST_HEAD(&serv->sv_permsocks);
397 init_timer(&serv->sv_temptimer);
398 spin_lock_init(&serv->sv_lock);
399
400 serv->sv_nrpools = npools;
401 serv->sv_pools =
402 kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
403 GFP_KERNEL);
404 if (!serv->sv_pools) {
405 kfree(serv);
406 return NULL;
407 }
408
409 for (i = 0; i < serv->sv_nrpools; i++) {
410 struct svc_pool *pool = &serv->sv_pools[i];
411
412 dprintk("svc: initialising pool %u for %s\n",
413 i, serv->sv_name);
414
415 pool->sp_id = i;
416 INIT_LIST_HEAD(&pool->sp_threads);
417 INIT_LIST_HEAD(&pool->sp_sockets);
418 INIT_LIST_HEAD(&pool->sp_all_threads);
419 spin_lock_init(&pool->sp_lock);
420 }
421
422 /* Remove any stale portmap registrations */
423 svc_unregister(serv);
424
425 return serv;
426}
427
428struct svc_serv *
429svc_create(struct svc_program *prog, unsigned int bufsize,
430 void (*shutdown)(struct svc_serv *serv))
431{
432 return __svc_create(prog, bufsize, /*npools*/1, shutdown);
433}
434EXPORT_SYMBOL_GPL(svc_create);
435
436struct svc_serv *
437svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
438 void (*shutdown)(struct svc_serv *serv),
439 svc_thread_fn func, struct module *mod)
440{
441 struct svc_serv *serv;
442 unsigned int npools = svc_pool_map_get();
443
444 serv = __svc_create(prog, bufsize, npools, shutdown);
445
446 if (serv != NULL) {
447 serv->sv_function = func;
448 serv->sv_module = mod;
449 }
450
451 return serv;
452}
453EXPORT_SYMBOL_GPL(svc_create_pooled);
454
455/*
456 * Destroy an RPC service. Should be called with appropriate locking to
457 * protect the sv_nrthreads, sv_permsocks and sv_tempsocks.
458 */
459void
460svc_destroy(struct svc_serv *serv)
461{
462 dprintk("svc: svc_destroy(%s, %d)\n",
463 serv->sv_program->pg_name,
464 serv->sv_nrthreads);
465
466 if (serv->sv_nrthreads) {
467 if (--(serv->sv_nrthreads) != 0) {
468 svc_sock_update_bufs(serv);
469 return;
470 }
471 } else
472 printk("svc_destroy: no threads for serv=%p!\n", serv);
473
474 del_timer_sync(&serv->sv_temptimer);
475
476 svc_close_all(&serv->sv_tempsocks);
477
478 if (serv->sv_shutdown)
479 serv->sv_shutdown(serv);
480
481 svc_close_all(&serv->sv_permsocks);
482
483 BUG_ON(!list_empty(&serv->sv_permsocks));
484 BUG_ON(!list_empty(&serv->sv_tempsocks));
485
486 cache_clean_deferred(serv);
487
488 if (svc_serv_is_pooled(serv))
489 svc_pool_map_put();
490
491 svc_unregister(serv);
492 kfree(serv->sv_pools);
493 kfree(serv);
494}
495EXPORT_SYMBOL_GPL(svc_destroy);
496
497/*
498 * Allocate an RPC server's buffer space.
499 * We allocate pages and place them in rq_argpages.
500 */
501static int
502svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
503{
504 unsigned int pages, arghi;
505
506 /* bc_xprt uses fore channel allocated buffers */
507 if (svc_is_backchannel(rqstp))
508 return 1;
509
510 pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
511 * We assume one is at most one page
512 */
513 arghi = 0;
514 BUG_ON(pages > RPCSVC_MAXPAGES);
515 while (pages) {
516 struct page *p = alloc_page(GFP_KERNEL);
517 if (!p)
518 break;
519 rqstp->rq_pages[arghi++] = p;
520 pages--;
521 }
522 return pages == 0;
523}
524
525/*
526 * Release an RPC server buffer
527 */
528static void
529svc_release_buffer(struct svc_rqst *rqstp)
530{
531 unsigned int i;
532
533 for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
534 if (rqstp->rq_pages[i])
535 put_page(rqstp->rq_pages[i]);
536}
537
538struct svc_rqst *
539svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
540{
541 struct svc_rqst *rqstp;
542
543 rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
544 if (!rqstp)
545 goto out_enomem;
546
547 init_waitqueue_head(&rqstp->rq_wait);
548
549 serv->sv_nrthreads++;
550 spin_lock_bh(&pool->sp_lock);
551 pool->sp_nrthreads++;
552 list_add(&rqstp->rq_all, &pool->sp_all_threads);
553 spin_unlock_bh(&pool->sp_lock);
554 rqstp->rq_server = serv;
555 rqstp->rq_pool = pool;
556
557 rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
558 if (!rqstp->rq_argp)
559 goto out_thread;
560
561 rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
562 if (!rqstp->rq_resp)
563 goto out_thread;
564
565 if (!svc_init_buffer(rqstp, serv->sv_max_mesg))
566 goto out_thread;
567
568 return rqstp;
569out_thread:
570 svc_exit_thread(rqstp);
571out_enomem:
572 return ERR_PTR(-ENOMEM);
573}
574EXPORT_SYMBOL_GPL(svc_prepare_thread);
575
576/*
577 * Choose a pool in which to create a new thread, for svc_set_num_threads
578 */
579static inline struct svc_pool *
580choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
581{
582 if (pool != NULL)
583 return pool;
584
585 return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
586}
587
588/*
589 * Choose a thread to kill, for svc_set_num_threads
590 */
591static inline struct task_struct *
592choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
593{
594 unsigned int i;
595 struct task_struct *task = NULL;
596
597 if (pool != NULL) {
598 spin_lock_bh(&pool->sp_lock);
599 } else {
600 /* choose a pool in round-robin fashion */
601 for (i = 0; i < serv->sv_nrpools; i++) {
602 pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
603 spin_lock_bh(&pool->sp_lock);
604 if (!list_empty(&pool->sp_all_threads))
605 goto found_pool;
606 spin_unlock_bh(&pool->sp_lock);
607 }
608 return NULL;
609 }
610
611found_pool:
612 if (!list_empty(&pool->sp_all_threads)) {
613 struct svc_rqst *rqstp;
614
615 /*
616 * Remove from the pool->sp_all_threads list
617 * so we don't try to kill it again.
618 */
619 rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
620 list_del_init(&rqstp->rq_all);
621 task = rqstp->rq_task;
622 }
623 spin_unlock_bh(&pool->sp_lock);
624
625 return task;
626}
627
628/*
629 * Create or destroy enough new threads to make the number
630 * of threads the given number. If `pool' is non-NULL, applies
631 * only to threads in that pool, otherwise round-robins between
632 * all pools. Must be called with a svc_get() reference and
633 * the BKL or another lock to protect access to svc_serv fields.
634 *
635 * Destroying threads relies on the service threads filling in
636 * rqstp->rq_task, which only the nfs ones do. Assumes the serv
637 * has been created using svc_create_pooled().
638 *
639 * Based on code that used to be in nfsd_svc() but tweaked
640 * to be pool-aware.
641 */
642int
643svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
644{
645 struct svc_rqst *rqstp;
646 struct task_struct *task;
647 struct svc_pool *chosen_pool;
648 int error = 0;
649 unsigned int state = serv->sv_nrthreads-1;
650
651 if (pool == NULL) {
652 /* The -1 assumes caller has done a svc_get() */
653 nrservs -= (serv->sv_nrthreads-1);
654 } else {
655 spin_lock_bh(&pool->sp_lock);
656 nrservs -= pool->sp_nrthreads;
657 spin_unlock_bh(&pool->sp_lock);
658 }
659
660 /* create new threads */
661 while (nrservs > 0) {
662 nrservs--;
663 chosen_pool = choose_pool(serv, pool, &state);
664
665 rqstp = svc_prepare_thread(serv, chosen_pool);
666 if (IS_ERR(rqstp)) {
667 error = PTR_ERR(rqstp);
668 break;
669 }
670
671 __module_get(serv->sv_module);
672 task = kthread_create(serv->sv_function, rqstp, serv->sv_name);
673 if (IS_ERR(task)) {
674 error = PTR_ERR(task);
675 module_put(serv->sv_module);
676 svc_exit_thread(rqstp);
677 break;
678 }
679
680 rqstp->rq_task = task;
681 if (serv->sv_nrpools > 1)
682 svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
683
684 svc_sock_update_bufs(serv);
685 wake_up_process(task);
686 }
687 /* destroy old threads */
688 while (nrservs < 0 &&
689 (task = choose_victim(serv, pool, &state)) != NULL) {
690 send_sig(SIGINT, task, 1);
691 nrservs++;
692 }
693
694 return error;
695}
696EXPORT_SYMBOL_GPL(svc_set_num_threads);
697
698/*
699 * Called from a server thread as it's exiting. Caller must hold the BKL or
700 * the "service mutex", whichever is appropriate for the service.
701 */
702void
703svc_exit_thread(struct svc_rqst *rqstp)
704{
705 struct svc_serv *serv = rqstp->rq_server;
706 struct svc_pool *pool = rqstp->rq_pool;
707
708 svc_release_buffer(rqstp);
709 kfree(rqstp->rq_resp);
710 kfree(rqstp->rq_argp);
711 kfree(rqstp->rq_auth_data);
712
713 spin_lock_bh(&pool->sp_lock);
714 pool->sp_nrthreads--;
715 list_del(&rqstp->rq_all);
716 spin_unlock_bh(&pool->sp_lock);
717
718 kfree(rqstp);
719
720 /* Release the server */
721 if (serv)
722 svc_destroy(serv);
723}
724EXPORT_SYMBOL_GPL(svc_exit_thread);
725
726/*
727 * Register an "inet" protocol family netid with the local
728 * rpcbind daemon via an rpcbind v4 SET request.
729 *
730 * No netconfig infrastructure is available in the kernel, so
731 * we map IP_ protocol numbers to netids by hand.
732 *
733 * Returns zero on success; a negative errno value is returned
734 * if any error occurs.
735 */
736static int __svc_rpcb_register4(const u32 program, const u32 version,
737 const unsigned short protocol,
738 const unsigned short port)
739{
740 const struct sockaddr_in sin = {
741 .sin_family = AF_INET,
742 .sin_addr.s_addr = htonl(INADDR_ANY),
743 .sin_port = htons(port),
744 };
745 const char *netid;
746 int error;
747
748 switch (protocol) {
749 case IPPROTO_UDP:
750 netid = RPCBIND_NETID_UDP;
751 break;
752 case IPPROTO_TCP:
753 netid = RPCBIND_NETID_TCP;
754 break;
755 default:
756 return -ENOPROTOOPT;
757 }
758
759 error = rpcb_v4_register(program, version,
760 (const struct sockaddr *)&sin, netid);
761
762 /*
763 * User space didn't support rpcbind v4, so retry this
764 * registration request with the legacy rpcbind v2 protocol.
765 */
766 if (error == -EPROTONOSUPPORT)
767 error = rpcb_register(program, version, protocol, port);
768
769 return error;
770}
771
772#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
773/*
774 * Register an "inet6" protocol family netid with the local
775 * rpcbind daemon via an rpcbind v4 SET request.
776 *
777 * No netconfig infrastructure is available in the kernel, so
778 * we map IP_ protocol numbers to netids by hand.
779 *
780 * Returns zero on success; a negative errno value is returned
781 * if any error occurs.
782 */
783static int __svc_rpcb_register6(const u32 program, const u32 version,
784 const unsigned short protocol,
785 const unsigned short port)
786{
787 const struct sockaddr_in6 sin6 = {
788 .sin6_family = AF_INET6,
789 .sin6_addr = IN6ADDR_ANY_INIT,
790 .sin6_port = htons(port),
791 };
792 const char *netid;
793 int error;
794
795 switch (protocol) {
796 case IPPROTO_UDP:
797 netid = RPCBIND_NETID_UDP6;
798 break;
799 case IPPROTO_TCP:
800 netid = RPCBIND_NETID_TCP6;
801 break;
802 default:
803 return -ENOPROTOOPT;
804 }
805
806 error = rpcb_v4_register(program, version,
807 (const struct sockaddr *)&sin6, netid);
808
809 /*
810 * User space didn't support rpcbind version 4, so we won't
811 * use a PF_INET6 listener.
812 */
813 if (error == -EPROTONOSUPPORT)
814 error = -EAFNOSUPPORT;
815
816 return error;
817}
818#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
819
820/*
821 * Register a kernel RPC service via rpcbind version 4.
822 *
823 * Returns zero on success; a negative errno value is returned
824 * if any error occurs.
825 */
826static int __svc_register(const char *progname,
827 const u32 program, const u32 version,
828 const int family,
829 const unsigned short protocol,
830 const unsigned short port)
831{
832 int error = -EAFNOSUPPORT;
833
834 switch (family) {
835 case PF_INET:
836 error = __svc_rpcb_register4(program, version,
837 protocol, port);
838 break;
839#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
840 case PF_INET6:
841 error = __svc_rpcb_register6(program, version,
842 protocol, port);
843#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
844 }
845
846 if (error < 0)
847 printk(KERN_WARNING "svc: failed to register %sv%u RPC "
848 "service (errno %d).\n", progname, version, -error);
849 return error;
850}
851
852/**
853 * svc_register - register an RPC service with the local portmapper
854 * @serv: svc_serv struct for the service to register
855 * @family: protocol family of service's listener socket
856 * @proto: transport protocol number to advertise
857 * @port: port to advertise
858 *
859 * Service is registered for any address in the passed-in protocol family
860 */
861int svc_register(const struct svc_serv *serv, const int family,
862 const unsigned short proto, const unsigned short port)
863{
864 struct svc_program *progp;
865 unsigned int i;
866 int error = 0;
867
868 BUG_ON(proto == 0 && port == 0);
869
870 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
871 for (i = 0; i < progp->pg_nvers; i++) {
872 if (progp->pg_vers[i] == NULL)
873 continue;
874
875 dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
876 progp->pg_name,
877 i,
878 proto == IPPROTO_UDP? "udp" : "tcp",
879 port,
880 family,
881 progp->pg_vers[i]->vs_hidden?
882 " (but not telling portmap)" : "");
883
884 if (progp->pg_vers[i]->vs_hidden)
885 continue;
886
887 error = __svc_register(progp->pg_name, progp->pg_prog,
888 i, family, proto, port);
889 if (error < 0)
890 break;
891 }
892 }
893
894 return error;
895}
896
897/*
898 * If user space is running rpcbind, it should take the v4 UNSET
899 * and clear everything for this [program, version]. If user space
900 * is running portmap, it will reject the v4 UNSET, but won't have
901 * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient
902 * in this case to clear all existing entries for [program, version].
903 */
904static void __svc_unregister(const u32 program, const u32 version,
905 const char *progname)
906{
907 int error;
908
909 error = rpcb_v4_register(program, version, NULL, "");
910
911 /*
912 * User space didn't support rpcbind v4, so retry this
913 * request with the legacy rpcbind v2 protocol.
914 */
915 if (error == -EPROTONOSUPPORT)
916 error = rpcb_register(program, version, 0, 0);
917
918 dprintk("svc: %s(%sv%u), error %d\n",
919 __func__, progname, version, error);
920}
921
922/*
923 * All netids, bind addresses and ports registered for [program, version]
924 * are removed from the local rpcbind database (if the service is not
925 * hidden) to make way for a new instance of the service.
926 *
927 * The result of unregistration is reported via dprintk for those who want
928 * verification of the result, but is otherwise not important.
929 */
930static void svc_unregister(const struct svc_serv *serv)
931{
932 struct svc_program *progp;
933 unsigned long flags;
934 unsigned int i;
935
936 clear_thread_flag(TIF_SIGPENDING);
937
938 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
939 for (i = 0; i < progp->pg_nvers; i++) {
940 if (progp->pg_vers[i] == NULL)
941 continue;
942 if (progp->pg_vers[i]->vs_hidden)
943 continue;
944
945 dprintk("svc: attempting to unregister %sv%u\n",
946 progp->pg_name, i);
947 __svc_unregister(progp->pg_prog, i, progp->pg_name);
948 }
949 }
950
951 spin_lock_irqsave(¤t->sighand->siglock, flags);
952 recalc_sigpending();
953 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
954}
955
956/*
957 * Printk the given error with the address of the client that caused it.
958 */
959static int
960__attribute__ ((format (printf, 2, 3)))
961svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
962{
963 va_list args;
964 int r;
965 char buf[RPC_MAX_ADDRBUFLEN];
966
967 if (!net_ratelimit())
968 return 0;
969
970 printk(KERN_WARNING "svc: %s: ",
971 svc_print_addr(rqstp, buf, sizeof(buf)));
972
973 va_start(args, fmt);
974 r = vprintk(fmt, args);
975 va_end(args);
976
977 return r;
978}
979
980/*
981 * Common routine for processing the RPC request.
982 */
983static int
984svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
985{
986 struct svc_program *progp;
987 struct svc_version *versp = NULL; /* compiler food */
988 struct svc_procedure *procp = NULL;
989 struct svc_serv *serv = rqstp->rq_server;
990 kxdrproc_t xdr;
991 __be32 *statp;
992 u32 prog, vers, proc;
993 __be32 auth_stat, rpc_stat;
994 int auth_res;
995 __be32 *reply_statp;
996
997 rpc_stat = rpc_success;
998
999 if (argv->iov_len < 6*4)
1000 goto err_short_len;
1001
1002 /* Will be turned off only in gss privacy case: */
1003 rqstp->rq_splice_ok = 1;
1004 /* Will be turned off only when NFSv4 Sessions are used */
1005 rqstp->rq_usedeferral = 1;
1006 rqstp->rq_dropme = false;
1007
1008 /* Setup reply header */
1009 rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
1010
1011 svc_putu32(resv, rqstp->rq_xid);
1012
1013 vers = svc_getnl(argv);
1014
1015 /* First words of reply: */
1016 svc_putnl(resv, 1); /* REPLY */
1017
1018 if (vers != 2) /* RPC version number */
1019 goto err_bad_rpc;
1020
1021 /* Save position in case we later decide to reject: */
1022 reply_statp = resv->iov_base + resv->iov_len;
1023
1024 svc_putnl(resv, 0); /* ACCEPT */
1025
1026 rqstp->rq_prog = prog = svc_getnl(argv); /* program number */
1027 rqstp->rq_vers = vers = svc_getnl(argv); /* version number */
1028 rqstp->rq_proc = proc = svc_getnl(argv); /* procedure number */
1029
1030 progp = serv->sv_program;
1031
1032 for (progp = serv->sv_program; progp; progp = progp->pg_next)
1033 if (prog == progp->pg_prog)
1034 break;
1035
1036 /*
1037 * Decode auth data, and add verifier to reply buffer.
1038 * We do this before anything else in order to get a decent
1039 * auth verifier.
1040 */
1041 auth_res = svc_authenticate(rqstp, &auth_stat);
1042 /* Also give the program a chance to reject this call: */
1043 if (auth_res == SVC_OK && progp) {
1044 auth_stat = rpc_autherr_badcred;
1045 auth_res = progp->pg_authenticate(rqstp);
1046 }
1047 switch (auth_res) {
1048 case SVC_OK:
1049 break;
1050 case SVC_GARBAGE:
1051 goto err_garbage;
1052 case SVC_SYSERR:
1053 rpc_stat = rpc_system_err;
1054 goto err_bad;
1055 case SVC_DENIED:
1056 goto err_bad_auth;
1057 case SVC_CLOSE:
1058 if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1059 svc_close_xprt(rqstp->rq_xprt);
1060 case SVC_DROP:
1061 goto dropit;
1062 case SVC_COMPLETE:
1063 goto sendit;
1064 }
1065
1066 if (progp == NULL)
1067 goto err_bad_prog;
1068
1069 if (vers >= progp->pg_nvers ||
1070 !(versp = progp->pg_vers[vers]))
1071 goto err_bad_vers;
1072
1073 procp = versp->vs_proc + proc;
1074 if (proc >= versp->vs_nproc || !procp->pc_func)
1075 goto err_bad_proc;
1076 rqstp->rq_procinfo = procp;
1077
1078 /* Syntactic check complete */
1079 serv->sv_stats->rpccnt++;
1080
1081 /* Build the reply header. */
1082 statp = resv->iov_base +resv->iov_len;
1083 svc_putnl(resv, RPC_SUCCESS);
1084
1085 /* Bump per-procedure stats counter */
1086 procp->pc_count++;
1087
1088 /* Initialize storage for argp and resp */
1089 memset(rqstp->rq_argp, 0, procp->pc_argsize);
1090 memset(rqstp->rq_resp, 0, procp->pc_ressize);
1091
1092 /* un-reserve some of the out-queue now that we have a
1093 * better idea of reply size
1094 */
1095 if (procp->pc_xdrressize)
1096 svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1097
1098 /* Call the function that processes the request. */
1099 if (!versp->vs_dispatch) {
1100 /* Decode arguments */
1101 xdr = procp->pc_decode;
1102 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
1103 goto err_garbage;
1104
1105 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
1106
1107 /* Encode reply */
1108 if (rqstp->rq_dropme) {
1109 if (procp->pc_release)
1110 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1111 goto dropit;
1112 }
1113 if (*statp == rpc_success &&
1114 (xdr = procp->pc_encode) &&
1115 !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
1116 dprintk("svc: failed to encode reply\n");
1117 /* serv->sv_stats->rpcsystemerr++; */
1118 *statp = rpc_system_err;
1119 }
1120 } else {
1121 dprintk("svc: calling dispatcher\n");
1122 if (!versp->vs_dispatch(rqstp, statp)) {
1123 /* Release reply info */
1124 if (procp->pc_release)
1125 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1126 goto dropit;
1127 }
1128 }
1129
1130 /* Check RPC status result */
1131 if (*statp != rpc_success)
1132 resv->iov_len = ((void*)statp) - resv->iov_base + 4;
1133
1134 /* Release reply info */
1135 if (procp->pc_release)
1136 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1137
1138 if (procp->pc_encode == NULL)
1139 goto dropit;
1140
1141 sendit:
1142 if (svc_authorise(rqstp))
1143 goto dropit;
1144 return 1; /* Caller can now send it */
1145
1146 dropit:
1147 svc_authorise(rqstp); /* doesn't hurt to call this twice */
1148 dprintk("svc: svc_process dropit\n");
1149 return 0;
1150
1151err_short_len:
1152 svc_printk(rqstp, "short len %Zd, dropping request\n",
1153 argv->iov_len);
1154
1155 goto dropit; /* drop request */
1156
1157err_bad_rpc:
1158 serv->sv_stats->rpcbadfmt++;
1159 svc_putnl(resv, 1); /* REJECT */
1160 svc_putnl(resv, 0); /* RPC_MISMATCH */
1161 svc_putnl(resv, 2); /* Only RPCv2 supported */
1162 svc_putnl(resv, 2);
1163 goto sendit;
1164
1165err_bad_auth:
1166 dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
1167 serv->sv_stats->rpcbadauth++;
1168 /* Restore write pointer to location of accept status: */
1169 xdr_ressize_check(rqstp, reply_statp);
1170 svc_putnl(resv, 1); /* REJECT */
1171 svc_putnl(resv, 1); /* AUTH_ERROR */
1172 svc_putnl(resv, ntohl(auth_stat)); /* status */
1173 goto sendit;
1174
1175err_bad_prog:
1176 dprintk("svc: unknown program %d\n", prog);
1177 serv->sv_stats->rpcbadfmt++;
1178 svc_putnl(resv, RPC_PROG_UNAVAIL);
1179 goto sendit;
1180
1181err_bad_vers:
1182 svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1183 vers, prog, progp->pg_name);
1184
1185 serv->sv_stats->rpcbadfmt++;
1186 svc_putnl(resv, RPC_PROG_MISMATCH);
1187 svc_putnl(resv, progp->pg_lovers);
1188 svc_putnl(resv, progp->pg_hivers);
1189 goto sendit;
1190
1191err_bad_proc:
1192 svc_printk(rqstp, "unknown procedure (%d)\n", proc);
1193
1194 serv->sv_stats->rpcbadfmt++;
1195 svc_putnl(resv, RPC_PROC_UNAVAIL);
1196 goto sendit;
1197
1198err_garbage:
1199 svc_printk(rqstp, "failed to decode args\n");
1200
1201 rpc_stat = rpc_garbage_args;
1202err_bad:
1203 serv->sv_stats->rpcbadfmt++;
1204 svc_putnl(resv, ntohl(rpc_stat));
1205 goto sendit;
1206}
1207EXPORT_SYMBOL_GPL(svc_process);
1208
1209/*
1210 * Process the RPC request.
1211 */
1212int
1213svc_process(struct svc_rqst *rqstp)
1214{
1215 struct kvec *argv = &rqstp->rq_arg.head[0];
1216 struct kvec *resv = &rqstp->rq_res.head[0];
1217 struct svc_serv *serv = rqstp->rq_server;
1218 u32 dir;
1219
1220 /*
1221 * Setup response xdr_buf.
1222 * Initially it has just one page
1223 */
1224 rqstp->rq_resused = 1;
1225 resv->iov_base = page_address(rqstp->rq_respages[0]);
1226 resv->iov_len = 0;
1227 rqstp->rq_res.pages = rqstp->rq_respages + 1;
1228 rqstp->rq_res.len = 0;
1229 rqstp->rq_res.page_base = 0;
1230 rqstp->rq_res.page_len = 0;
1231 rqstp->rq_res.buflen = PAGE_SIZE;
1232 rqstp->rq_res.tail[0].iov_base = NULL;
1233 rqstp->rq_res.tail[0].iov_len = 0;
1234
1235 rqstp->rq_xid = svc_getu32(argv);
1236
1237 dir = svc_getnl(argv);
1238 if (dir != 0) {
1239 /* direction != CALL */
1240 svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
1241 serv->sv_stats->rpcbadfmt++;
1242 svc_drop(rqstp);
1243 return 0;
1244 }
1245
1246 /* Returns 1 for send, 0 for drop */
1247 if (svc_process_common(rqstp, argv, resv))
1248 return svc_send(rqstp);
1249 else {
1250 svc_drop(rqstp);
1251 return 0;
1252 }
1253}
1254
1255#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1256/*
1257 * Process a backchannel RPC request that arrived over an existing
1258 * outbound connection
1259 */
1260int
1261bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
1262 struct svc_rqst *rqstp)
1263{
1264 struct kvec *argv = &rqstp->rq_arg.head[0];
1265 struct kvec *resv = &rqstp->rq_res.head[0];
1266
1267 /* Build the svc_rqst used by the common processing routine */
1268 rqstp->rq_xprt = serv->sv_bc_xprt;
1269 rqstp->rq_xid = req->rq_xid;
1270 rqstp->rq_prot = req->rq_xprt->prot;
1271 rqstp->rq_server = serv;
1272
1273 rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1274 memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1275 memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1276 memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1277
1278 /* reset result send buffer "put" position */
1279 resv->iov_len = 0;
1280
1281 if (rqstp->rq_prot != IPPROTO_TCP) {
1282 printk(KERN_ERR "No support for Non-TCP transports!\n");
1283 BUG();
1284 }
1285
1286 /*
1287 * Skip the next two words because they've already been
1288 * processed in the trasport
1289 */
1290 svc_getu32(argv); /* XID */
1291 svc_getnl(argv); /* CALLDIR */
1292
1293 /* Returns 1 for send, 0 for drop */
1294 if (svc_process_common(rqstp, argv, resv)) {
1295 memcpy(&req->rq_snd_buf, &rqstp->rq_res,
1296 sizeof(req->rq_snd_buf));
1297 return bc_send(req);
1298 } else {
1299 /* Nothing to do to drop request */
1300 return 0;
1301 }
1302}
1303EXPORT_SYMBOL_GPL(bc_svc_process);
1304#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1305
1306/*
1307 * Return (transport-specific) limit on the rpc payload.
1308 */
1309u32 svc_max_payload(const struct svc_rqst *rqstp)
1310{
1311 u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1312
1313 if (rqstp->rq_server->sv_max_payload < max)
1314 max = rqstp->rq_server->sv_max_payload;
1315 return max;
1316}
1317EXPORT_SYMBOL_GPL(svc_max_payload);