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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/svc.c
4 *
5 * High-level RPC service routines
6 *
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
8 *
9 * Multiple threads pools and NUMAisation
10 * Copyright (c) 2006 Silicon Graphics, Inc.
11 * by Greg Banks <gnb@melbourne.sgi.com>
12 */
13
14#include <linux/linkage.h>
15#include <linux/sched/signal.h>
16#include <linux/errno.h>
17#include <linux/net.h>
18#include <linux/in.h>
19#include <linux/mm.h>
20#include <linux/interrupt.h>
21#include <linux/module.h>
22#include <linux/kthread.h>
23#include <linux/slab.h>
24
25#include <linux/sunrpc/types.h>
26#include <linux/sunrpc/xdr.h>
27#include <linux/sunrpc/stats.h>
28#include <linux/sunrpc/svcsock.h>
29#include <linux/sunrpc/clnt.h>
30#include <linux/sunrpc/bc_xprt.h>
31
32#include <trace/events/sunrpc.h>
33
34#include "fail.h"
35
36#define RPCDBG_FACILITY RPCDBG_SVCDSP
37
38static void svc_unregister(const struct svc_serv *serv, struct net *net);
39
40#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
41
42/*
43 * Mode for mapping cpus to pools.
44 */
45enum {
46 SVC_POOL_AUTO = -1, /* choose one of the others */
47 SVC_POOL_GLOBAL, /* no mapping, just a single global pool
48 * (legacy & UP mode) */
49 SVC_POOL_PERCPU, /* one pool per cpu */
50 SVC_POOL_PERNODE /* one pool per numa node */
51};
52
53/*
54 * Structure for mapping cpus to pools and vice versa.
55 * Setup once during sunrpc initialisation.
56 */
57
58struct svc_pool_map {
59 int count; /* How many svc_servs use us */
60 int mode; /* Note: int not enum to avoid
61 * warnings about "enumeration value
62 * not handled in switch" */
63 unsigned int npools;
64 unsigned int *pool_to; /* maps pool id to cpu or node */
65 unsigned int *to_pool; /* maps cpu or node to pool id */
66};
67
68static struct svc_pool_map svc_pool_map = {
69 .mode = SVC_POOL_DEFAULT
70};
71
72static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
73
74static int
75param_set_pool_mode(const char *val, const struct kernel_param *kp)
76{
77 int *ip = (int *)kp->arg;
78 struct svc_pool_map *m = &svc_pool_map;
79 int err;
80
81 mutex_lock(&svc_pool_map_mutex);
82
83 err = -EBUSY;
84 if (m->count)
85 goto out;
86
87 err = 0;
88 if (!strncmp(val, "auto", 4))
89 *ip = SVC_POOL_AUTO;
90 else if (!strncmp(val, "global", 6))
91 *ip = SVC_POOL_GLOBAL;
92 else if (!strncmp(val, "percpu", 6))
93 *ip = SVC_POOL_PERCPU;
94 else if (!strncmp(val, "pernode", 7))
95 *ip = SVC_POOL_PERNODE;
96 else
97 err = -EINVAL;
98
99out:
100 mutex_unlock(&svc_pool_map_mutex);
101 return err;
102}
103
104static int
105param_get_pool_mode(char *buf, const struct kernel_param *kp)
106{
107 int *ip = (int *)kp->arg;
108
109 switch (*ip)
110 {
111 case SVC_POOL_AUTO:
112 return sysfs_emit(buf, "auto\n");
113 case SVC_POOL_GLOBAL:
114 return sysfs_emit(buf, "global\n");
115 case SVC_POOL_PERCPU:
116 return sysfs_emit(buf, "percpu\n");
117 case SVC_POOL_PERNODE:
118 return sysfs_emit(buf, "pernode\n");
119 default:
120 return sysfs_emit(buf, "%d\n", *ip);
121 }
122}
123
124module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
125 &svc_pool_map.mode, 0644);
126
127/*
128 * Detect best pool mapping mode heuristically,
129 * according to the machine's topology.
130 */
131static int
132svc_pool_map_choose_mode(void)
133{
134 unsigned int node;
135
136 if (nr_online_nodes > 1) {
137 /*
138 * Actually have multiple NUMA nodes,
139 * so split pools on NUMA node boundaries
140 */
141 return SVC_POOL_PERNODE;
142 }
143
144 node = first_online_node;
145 if (nr_cpus_node(node) > 2) {
146 /*
147 * Non-trivial SMP, or CONFIG_NUMA on
148 * non-NUMA hardware, e.g. with a generic
149 * x86_64 kernel on Xeons. In this case we
150 * want to divide the pools on cpu boundaries.
151 */
152 return SVC_POOL_PERCPU;
153 }
154
155 /* default: one global pool */
156 return SVC_POOL_GLOBAL;
157}
158
159/*
160 * Allocate the to_pool[] and pool_to[] arrays.
161 * Returns 0 on success or an errno.
162 */
163static int
164svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
165{
166 m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
167 if (!m->to_pool)
168 goto fail;
169 m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
170 if (!m->pool_to)
171 goto fail_free;
172
173 return 0;
174
175fail_free:
176 kfree(m->to_pool);
177 m->to_pool = NULL;
178fail:
179 return -ENOMEM;
180}
181
182/*
183 * Initialise the pool map for SVC_POOL_PERCPU mode.
184 * Returns number of pools or <0 on error.
185 */
186static int
187svc_pool_map_init_percpu(struct svc_pool_map *m)
188{
189 unsigned int maxpools = nr_cpu_ids;
190 unsigned int pidx = 0;
191 unsigned int cpu;
192 int err;
193
194 err = svc_pool_map_alloc_arrays(m, maxpools);
195 if (err)
196 return err;
197
198 for_each_online_cpu(cpu) {
199 BUG_ON(pidx >= maxpools);
200 m->to_pool[cpu] = pidx;
201 m->pool_to[pidx] = cpu;
202 pidx++;
203 }
204 /* cpus brought online later all get mapped to pool0, sorry */
205
206 return pidx;
207};
208
209
210/*
211 * Initialise the pool map for SVC_POOL_PERNODE mode.
212 * Returns number of pools or <0 on error.
213 */
214static int
215svc_pool_map_init_pernode(struct svc_pool_map *m)
216{
217 unsigned int maxpools = nr_node_ids;
218 unsigned int pidx = 0;
219 unsigned int node;
220 int err;
221
222 err = svc_pool_map_alloc_arrays(m, maxpools);
223 if (err)
224 return err;
225
226 for_each_node_with_cpus(node) {
227 /* some architectures (e.g. SN2) have cpuless nodes */
228 BUG_ON(pidx > maxpools);
229 m->to_pool[node] = pidx;
230 m->pool_to[pidx] = node;
231 pidx++;
232 }
233 /* nodes brought online later all get mapped to pool0, sorry */
234
235 return pidx;
236}
237
238
239/*
240 * Add a reference to the global map of cpus to pools (and
241 * vice versa) if pools are in use.
242 * Initialise the map if we're the first user.
243 * Returns the number of pools. If this is '1', no reference
244 * was taken.
245 */
246static unsigned int
247svc_pool_map_get(void)
248{
249 struct svc_pool_map *m = &svc_pool_map;
250 int npools = -1;
251
252 mutex_lock(&svc_pool_map_mutex);
253
254 if (m->count++) {
255 mutex_unlock(&svc_pool_map_mutex);
256 WARN_ON_ONCE(m->npools <= 1);
257 return m->npools;
258 }
259
260 if (m->mode == SVC_POOL_AUTO)
261 m->mode = svc_pool_map_choose_mode();
262
263 switch (m->mode) {
264 case SVC_POOL_PERCPU:
265 npools = svc_pool_map_init_percpu(m);
266 break;
267 case SVC_POOL_PERNODE:
268 npools = svc_pool_map_init_pernode(m);
269 break;
270 }
271
272 if (npools <= 0) {
273 /* default, or memory allocation failure */
274 npools = 1;
275 m->mode = SVC_POOL_GLOBAL;
276 }
277 m->npools = npools;
278
279 if (npools == 1)
280 /* service is unpooled, so doesn't hold a reference */
281 m->count--;
282
283 mutex_unlock(&svc_pool_map_mutex);
284 return npools;
285}
286
287/*
288 * Drop a reference to the global map of cpus to pools, if
289 * pools were in use, i.e. if npools > 1.
290 * When the last reference is dropped, the map data is
291 * freed; this allows the sysadmin to change the pool
292 * mode using the pool_mode module option without
293 * rebooting or re-loading sunrpc.ko.
294 */
295static void
296svc_pool_map_put(int npools)
297{
298 struct svc_pool_map *m = &svc_pool_map;
299
300 if (npools <= 1)
301 return;
302 mutex_lock(&svc_pool_map_mutex);
303
304 if (!--m->count) {
305 kfree(m->to_pool);
306 m->to_pool = NULL;
307 kfree(m->pool_to);
308 m->pool_to = NULL;
309 m->npools = 0;
310 }
311
312 mutex_unlock(&svc_pool_map_mutex);
313}
314
315static int svc_pool_map_get_node(unsigned int pidx)
316{
317 const struct svc_pool_map *m = &svc_pool_map;
318
319 if (m->count) {
320 if (m->mode == SVC_POOL_PERCPU)
321 return cpu_to_node(m->pool_to[pidx]);
322 if (m->mode == SVC_POOL_PERNODE)
323 return m->pool_to[pidx];
324 }
325 return NUMA_NO_NODE;
326}
327/*
328 * Set the given thread's cpus_allowed mask so that it
329 * will only run on cpus in the given pool.
330 */
331static inline void
332svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
333{
334 struct svc_pool_map *m = &svc_pool_map;
335 unsigned int node = m->pool_to[pidx];
336
337 /*
338 * The caller checks for sv_nrpools > 1, which
339 * implies that we've been initialized.
340 */
341 WARN_ON_ONCE(m->count == 0);
342 if (m->count == 0)
343 return;
344
345 switch (m->mode) {
346 case SVC_POOL_PERCPU:
347 {
348 set_cpus_allowed_ptr(task, cpumask_of(node));
349 break;
350 }
351 case SVC_POOL_PERNODE:
352 {
353 set_cpus_allowed_ptr(task, cpumask_of_node(node));
354 break;
355 }
356 }
357}
358
359/**
360 * svc_pool_for_cpu - Select pool to run a thread on this cpu
361 * @serv: An RPC service
362 *
363 * Use the active CPU and the svc_pool_map's mode setting to
364 * select the svc thread pool to use. Once initialized, the
365 * svc_pool_map does not change.
366 *
367 * Return value:
368 * A pointer to an svc_pool
369 */
370struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv)
371{
372 struct svc_pool_map *m = &svc_pool_map;
373 int cpu = raw_smp_processor_id();
374 unsigned int pidx = 0;
375
376 if (serv->sv_nrpools <= 1)
377 return serv->sv_pools;
378
379 switch (m->mode) {
380 case SVC_POOL_PERCPU:
381 pidx = m->to_pool[cpu];
382 break;
383 case SVC_POOL_PERNODE:
384 pidx = m->to_pool[cpu_to_node(cpu)];
385 break;
386 }
387
388 return &serv->sv_pools[pidx % serv->sv_nrpools];
389}
390
391int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
392{
393 int err;
394
395 err = rpcb_create_local(net);
396 if (err)
397 return err;
398
399 /* Remove any stale portmap registrations */
400 svc_unregister(serv, net);
401 return 0;
402}
403EXPORT_SYMBOL_GPL(svc_rpcb_setup);
404
405void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
406{
407 svc_unregister(serv, net);
408 rpcb_put_local(net);
409}
410EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
411
412static int svc_uses_rpcbind(struct svc_serv *serv)
413{
414 struct svc_program *progp;
415 unsigned int i;
416
417 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
418 for (i = 0; i < progp->pg_nvers; i++) {
419 if (progp->pg_vers[i] == NULL)
420 continue;
421 if (!progp->pg_vers[i]->vs_hidden)
422 return 1;
423 }
424 }
425
426 return 0;
427}
428
429int svc_bind(struct svc_serv *serv, struct net *net)
430{
431 if (!svc_uses_rpcbind(serv))
432 return 0;
433 return svc_rpcb_setup(serv, net);
434}
435EXPORT_SYMBOL_GPL(svc_bind);
436
437#if defined(CONFIG_SUNRPC_BACKCHANNEL)
438static void
439__svc_init_bc(struct svc_serv *serv)
440{
441 lwq_init(&serv->sv_cb_list);
442}
443#else
444static void
445__svc_init_bc(struct svc_serv *serv)
446{
447}
448#endif
449
450/*
451 * Create an RPC service
452 */
453static struct svc_serv *
454__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
455 int (*threadfn)(void *data))
456{
457 struct svc_serv *serv;
458 unsigned int vers;
459 unsigned int xdrsize;
460 unsigned int i;
461
462 if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
463 return NULL;
464 serv->sv_name = prog->pg_name;
465 serv->sv_program = prog;
466 serv->sv_stats = prog->pg_stats;
467 if (bufsize > RPCSVC_MAXPAYLOAD)
468 bufsize = RPCSVC_MAXPAYLOAD;
469 serv->sv_max_payload = bufsize? bufsize : 4096;
470 serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
471 serv->sv_threadfn = threadfn;
472 xdrsize = 0;
473 while (prog) {
474 prog->pg_lovers = prog->pg_nvers-1;
475 for (vers=0; vers<prog->pg_nvers ; vers++)
476 if (prog->pg_vers[vers]) {
477 prog->pg_hivers = vers;
478 if (prog->pg_lovers > vers)
479 prog->pg_lovers = vers;
480 if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
481 xdrsize = prog->pg_vers[vers]->vs_xdrsize;
482 }
483 prog = prog->pg_next;
484 }
485 serv->sv_xdrsize = xdrsize;
486 INIT_LIST_HEAD(&serv->sv_tempsocks);
487 INIT_LIST_HEAD(&serv->sv_permsocks);
488 timer_setup(&serv->sv_temptimer, NULL, 0);
489 spin_lock_init(&serv->sv_lock);
490
491 __svc_init_bc(serv);
492
493 serv->sv_nrpools = npools;
494 serv->sv_pools =
495 kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
496 GFP_KERNEL);
497 if (!serv->sv_pools) {
498 kfree(serv);
499 return NULL;
500 }
501
502 for (i = 0; i < serv->sv_nrpools; i++) {
503 struct svc_pool *pool = &serv->sv_pools[i];
504
505 dprintk("svc: initialising pool %u for %s\n",
506 i, serv->sv_name);
507
508 pool->sp_id = i;
509 lwq_init(&pool->sp_xprts);
510 INIT_LIST_HEAD(&pool->sp_all_threads);
511 init_llist_head(&pool->sp_idle_threads);
512
513 percpu_counter_init(&pool->sp_messages_arrived, 0, GFP_KERNEL);
514 percpu_counter_init(&pool->sp_sockets_queued, 0, GFP_KERNEL);
515 percpu_counter_init(&pool->sp_threads_woken, 0, GFP_KERNEL);
516 }
517
518 return serv;
519}
520
521/**
522 * svc_create - Create an RPC service
523 * @prog: the RPC program the new service will handle
524 * @bufsize: maximum message size for @prog
525 * @threadfn: a function to service RPC requests for @prog
526 *
527 * Returns an instantiated struct svc_serv object or NULL.
528 */
529struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize,
530 int (*threadfn)(void *data))
531{
532 return __svc_create(prog, bufsize, 1, threadfn);
533}
534EXPORT_SYMBOL_GPL(svc_create);
535
536/**
537 * svc_create_pooled - Create an RPC service with pooled threads
538 * @prog: the RPC program the new service will handle
539 * @bufsize: maximum message size for @prog
540 * @threadfn: a function to service RPC requests for @prog
541 *
542 * Returns an instantiated struct svc_serv object or NULL.
543 */
544struct svc_serv *svc_create_pooled(struct svc_program *prog,
545 unsigned int bufsize,
546 int (*threadfn)(void *data))
547{
548 struct svc_serv *serv;
549 unsigned int npools = svc_pool_map_get();
550
551 serv = __svc_create(prog, bufsize, npools, threadfn);
552 if (!serv)
553 goto out_err;
554 return serv;
555out_err:
556 svc_pool_map_put(npools);
557 return NULL;
558}
559EXPORT_SYMBOL_GPL(svc_create_pooled);
560
561/*
562 * Destroy an RPC service. Should be called with appropriate locking to
563 * protect sv_permsocks and sv_tempsocks.
564 */
565void
566svc_destroy(struct svc_serv **servp)
567{
568 struct svc_serv *serv = *servp;
569 unsigned int i;
570
571 *servp = NULL;
572
573 dprintk("svc: svc_destroy(%s)\n", serv->sv_program->pg_name);
574 timer_shutdown_sync(&serv->sv_temptimer);
575
576 /*
577 * Remaining transports at this point are not expected.
578 */
579 WARN_ONCE(!list_empty(&serv->sv_permsocks),
580 "SVC: permsocks remain for %s\n", serv->sv_program->pg_name);
581 WARN_ONCE(!list_empty(&serv->sv_tempsocks),
582 "SVC: tempsocks remain for %s\n", serv->sv_program->pg_name);
583
584 cache_clean_deferred(serv);
585
586 svc_pool_map_put(serv->sv_nrpools);
587
588 for (i = 0; i < serv->sv_nrpools; i++) {
589 struct svc_pool *pool = &serv->sv_pools[i];
590
591 percpu_counter_destroy(&pool->sp_messages_arrived);
592 percpu_counter_destroy(&pool->sp_sockets_queued);
593 percpu_counter_destroy(&pool->sp_threads_woken);
594 }
595 kfree(serv->sv_pools);
596 kfree(serv);
597}
598EXPORT_SYMBOL_GPL(svc_destroy);
599
600static bool
601svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
602{
603 unsigned long pages, ret;
604
605 /* bc_xprt uses fore channel allocated buffers */
606 if (svc_is_backchannel(rqstp))
607 return true;
608
609 pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
610 * We assume one is at most one page
611 */
612 WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
613 if (pages > RPCSVC_MAXPAGES)
614 pages = RPCSVC_MAXPAGES;
615
616 ret = alloc_pages_bulk_array_node(GFP_KERNEL, node, pages,
617 rqstp->rq_pages);
618 return ret == pages;
619}
620
621/*
622 * Release an RPC server buffer
623 */
624static void
625svc_release_buffer(struct svc_rqst *rqstp)
626{
627 unsigned int i;
628
629 for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
630 if (rqstp->rq_pages[i])
631 put_page(rqstp->rq_pages[i]);
632}
633
634struct svc_rqst *
635svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
636{
637 struct svc_rqst *rqstp;
638
639 rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
640 if (!rqstp)
641 return rqstp;
642
643 folio_batch_init(&rqstp->rq_fbatch);
644
645 rqstp->rq_server = serv;
646 rqstp->rq_pool = pool;
647
648 rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0);
649 if (!rqstp->rq_scratch_page)
650 goto out_enomem;
651
652 rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
653 if (!rqstp->rq_argp)
654 goto out_enomem;
655
656 rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
657 if (!rqstp->rq_resp)
658 goto out_enomem;
659
660 if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
661 goto out_enomem;
662
663 return rqstp;
664out_enomem:
665 svc_rqst_free(rqstp);
666 return NULL;
667}
668EXPORT_SYMBOL_GPL(svc_rqst_alloc);
669
670static struct svc_rqst *
671svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
672{
673 struct svc_rqst *rqstp;
674
675 rqstp = svc_rqst_alloc(serv, pool, node);
676 if (!rqstp)
677 return ERR_PTR(-ENOMEM);
678
679 spin_lock_bh(&serv->sv_lock);
680 serv->sv_nrthreads += 1;
681 spin_unlock_bh(&serv->sv_lock);
682
683 atomic_inc(&pool->sp_nrthreads);
684
685 /* Protected by whatever lock the service uses when calling
686 * svc_set_num_threads()
687 */
688 list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
689
690 return rqstp;
691}
692
693/**
694 * svc_pool_wake_idle_thread - Awaken an idle thread in @pool
695 * @pool: service thread pool
696 *
697 * Can be called from soft IRQ or process context. Finding an idle
698 * service thread and marking it BUSY is atomic with respect to
699 * other calls to svc_pool_wake_idle_thread().
700 *
701 */
702void svc_pool_wake_idle_thread(struct svc_pool *pool)
703{
704 struct svc_rqst *rqstp;
705 struct llist_node *ln;
706
707 rcu_read_lock();
708 ln = READ_ONCE(pool->sp_idle_threads.first);
709 if (ln) {
710 rqstp = llist_entry(ln, struct svc_rqst, rq_idle);
711 WRITE_ONCE(rqstp->rq_qtime, ktime_get());
712 if (!task_is_running(rqstp->rq_task)) {
713 wake_up_process(rqstp->rq_task);
714 trace_svc_wake_up(rqstp->rq_task->pid);
715 percpu_counter_inc(&pool->sp_threads_woken);
716 }
717 rcu_read_unlock();
718 return;
719 }
720 rcu_read_unlock();
721
722}
723EXPORT_SYMBOL_GPL(svc_pool_wake_idle_thread);
724
725static struct svc_pool *
726svc_pool_next(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
727{
728 return pool ? pool : &serv->sv_pools[(*state)++ % serv->sv_nrpools];
729}
730
731static struct svc_pool *
732svc_pool_victim(struct svc_serv *serv, struct svc_pool *target_pool,
733 unsigned int *state)
734{
735 struct svc_pool *pool;
736 unsigned int i;
737
738retry:
739 pool = target_pool;
740
741 if (pool != NULL) {
742 if (atomic_inc_not_zero(&pool->sp_nrthreads))
743 goto found_pool;
744 return NULL;
745 } else {
746 for (i = 0; i < serv->sv_nrpools; i++) {
747 pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
748 if (atomic_inc_not_zero(&pool->sp_nrthreads))
749 goto found_pool;
750 }
751 return NULL;
752 }
753
754found_pool:
755 set_bit(SP_VICTIM_REMAINS, &pool->sp_flags);
756 set_bit(SP_NEED_VICTIM, &pool->sp_flags);
757 if (!atomic_dec_and_test(&pool->sp_nrthreads))
758 return pool;
759 /* Nothing left in this pool any more */
760 clear_bit(SP_NEED_VICTIM, &pool->sp_flags);
761 clear_bit(SP_VICTIM_REMAINS, &pool->sp_flags);
762 goto retry;
763}
764
765static int
766svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
767{
768 struct svc_rqst *rqstp;
769 struct task_struct *task;
770 struct svc_pool *chosen_pool;
771 unsigned int state = serv->sv_nrthreads-1;
772 int node;
773
774 do {
775 nrservs--;
776 chosen_pool = svc_pool_next(serv, pool, &state);
777 node = svc_pool_map_get_node(chosen_pool->sp_id);
778
779 rqstp = svc_prepare_thread(serv, chosen_pool, node);
780 if (IS_ERR(rqstp))
781 return PTR_ERR(rqstp);
782 task = kthread_create_on_node(serv->sv_threadfn, rqstp,
783 node, "%s", serv->sv_name);
784 if (IS_ERR(task)) {
785 svc_exit_thread(rqstp);
786 return PTR_ERR(task);
787 }
788
789 rqstp->rq_task = task;
790 if (serv->sv_nrpools > 1)
791 svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
792
793 svc_sock_update_bufs(serv);
794 wake_up_process(task);
795 } while (nrservs > 0);
796
797 return 0;
798}
799
800static int
801svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
802{
803 unsigned int state = serv->sv_nrthreads-1;
804 struct svc_pool *victim;
805
806 do {
807 victim = svc_pool_victim(serv, pool, &state);
808 if (!victim)
809 break;
810 svc_pool_wake_idle_thread(victim);
811 wait_on_bit(&victim->sp_flags, SP_VICTIM_REMAINS,
812 TASK_IDLE);
813 nrservs++;
814 } while (nrservs < 0);
815 return 0;
816}
817
818/**
819 * svc_set_num_threads - adjust number of threads per RPC service
820 * @serv: RPC service to adjust
821 * @pool: Specific pool from which to choose threads, or NULL
822 * @nrservs: New number of threads for @serv (0 or less means kill all threads)
823 *
824 * Create or destroy threads to make the number of threads for @serv the
825 * given number. If @pool is non-NULL, change only threads in that pool;
826 * otherwise, round-robin between all pools for @serv. @serv's
827 * sv_nrthreads is adjusted for each thread created or destroyed.
828 *
829 * Caller must ensure mutual exclusion between this and server startup or
830 * shutdown.
831 *
832 * Returns zero on success or a negative errno if an error occurred while
833 * starting a thread.
834 */
835int
836svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
837{
838 if (!pool)
839 nrservs -= serv->sv_nrthreads;
840 else
841 nrservs -= atomic_read(&pool->sp_nrthreads);
842
843 if (nrservs > 0)
844 return svc_start_kthreads(serv, pool, nrservs);
845 if (nrservs < 0)
846 return svc_stop_kthreads(serv, pool, nrservs);
847 return 0;
848}
849EXPORT_SYMBOL_GPL(svc_set_num_threads);
850
851/**
852 * svc_rqst_replace_page - Replace one page in rq_pages[]
853 * @rqstp: svc_rqst with pages to replace
854 * @page: replacement page
855 *
856 * When replacing a page in rq_pages, batch the release of the
857 * replaced pages to avoid hammering the page allocator.
858 *
859 * Return values:
860 * %true: page replaced
861 * %false: array bounds checking failed
862 */
863bool svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page)
864{
865 struct page **begin = rqstp->rq_pages;
866 struct page **end = &rqstp->rq_pages[RPCSVC_MAXPAGES];
867
868 if (unlikely(rqstp->rq_next_page < begin || rqstp->rq_next_page > end)) {
869 trace_svc_replace_page_err(rqstp);
870 return false;
871 }
872
873 if (*rqstp->rq_next_page) {
874 if (!folio_batch_add(&rqstp->rq_fbatch,
875 page_folio(*rqstp->rq_next_page)))
876 __folio_batch_release(&rqstp->rq_fbatch);
877 }
878
879 get_page(page);
880 *(rqstp->rq_next_page++) = page;
881 return true;
882}
883EXPORT_SYMBOL_GPL(svc_rqst_replace_page);
884
885/**
886 * svc_rqst_release_pages - Release Reply buffer pages
887 * @rqstp: RPC transaction context
888 *
889 * Release response pages that might still be in flight after
890 * svc_send, and any spliced filesystem-owned pages.
891 */
892void svc_rqst_release_pages(struct svc_rqst *rqstp)
893{
894 int i, count = rqstp->rq_next_page - rqstp->rq_respages;
895
896 if (count) {
897 release_pages(rqstp->rq_respages, count);
898 for (i = 0; i < count; i++)
899 rqstp->rq_respages[i] = NULL;
900 }
901}
902
903/*
904 * Called from a server thread as it's exiting. Caller must hold the "service
905 * mutex" for the service.
906 */
907void
908svc_rqst_free(struct svc_rqst *rqstp)
909{
910 folio_batch_release(&rqstp->rq_fbatch);
911 svc_release_buffer(rqstp);
912 if (rqstp->rq_scratch_page)
913 put_page(rqstp->rq_scratch_page);
914 kfree(rqstp->rq_resp);
915 kfree(rqstp->rq_argp);
916 kfree(rqstp->rq_auth_data);
917 kfree_rcu(rqstp, rq_rcu_head);
918}
919EXPORT_SYMBOL_GPL(svc_rqst_free);
920
921void
922svc_exit_thread(struct svc_rqst *rqstp)
923{
924 struct svc_serv *serv = rqstp->rq_server;
925 struct svc_pool *pool = rqstp->rq_pool;
926
927 list_del_rcu(&rqstp->rq_all);
928
929 atomic_dec(&pool->sp_nrthreads);
930
931 spin_lock_bh(&serv->sv_lock);
932 serv->sv_nrthreads -= 1;
933 spin_unlock_bh(&serv->sv_lock);
934 svc_sock_update_bufs(serv);
935
936 svc_rqst_free(rqstp);
937
938 clear_and_wake_up_bit(SP_VICTIM_REMAINS, &pool->sp_flags);
939}
940EXPORT_SYMBOL_GPL(svc_exit_thread);
941
942/*
943 * Register an "inet" protocol family netid with the local
944 * rpcbind daemon via an rpcbind v4 SET request.
945 *
946 * No netconfig infrastructure is available in the kernel, so
947 * we map IP_ protocol numbers to netids by hand.
948 *
949 * Returns zero on success; a negative errno value is returned
950 * if any error occurs.
951 */
952static int __svc_rpcb_register4(struct net *net, const u32 program,
953 const u32 version,
954 const unsigned short protocol,
955 const unsigned short port)
956{
957 const struct sockaddr_in sin = {
958 .sin_family = AF_INET,
959 .sin_addr.s_addr = htonl(INADDR_ANY),
960 .sin_port = htons(port),
961 };
962 const char *netid;
963 int error;
964
965 switch (protocol) {
966 case IPPROTO_UDP:
967 netid = RPCBIND_NETID_UDP;
968 break;
969 case IPPROTO_TCP:
970 netid = RPCBIND_NETID_TCP;
971 break;
972 default:
973 return -ENOPROTOOPT;
974 }
975
976 error = rpcb_v4_register(net, program, version,
977 (const struct sockaddr *)&sin, netid);
978
979 /*
980 * User space didn't support rpcbind v4, so retry this
981 * registration request with the legacy rpcbind v2 protocol.
982 */
983 if (error == -EPROTONOSUPPORT)
984 error = rpcb_register(net, program, version, protocol, port);
985
986 return error;
987}
988
989#if IS_ENABLED(CONFIG_IPV6)
990/*
991 * Register an "inet6" protocol family netid with the local
992 * rpcbind daemon via an rpcbind v4 SET request.
993 *
994 * No netconfig infrastructure is available in the kernel, so
995 * we map IP_ protocol numbers to netids by hand.
996 *
997 * Returns zero on success; a negative errno value is returned
998 * if any error occurs.
999 */
1000static int __svc_rpcb_register6(struct net *net, const u32 program,
1001 const u32 version,
1002 const unsigned short protocol,
1003 const unsigned short port)
1004{
1005 const struct sockaddr_in6 sin6 = {
1006 .sin6_family = AF_INET6,
1007 .sin6_addr = IN6ADDR_ANY_INIT,
1008 .sin6_port = htons(port),
1009 };
1010 const char *netid;
1011 int error;
1012
1013 switch (protocol) {
1014 case IPPROTO_UDP:
1015 netid = RPCBIND_NETID_UDP6;
1016 break;
1017 case IPPROTO_TCP:
1018 netid = RPCBIND_NETID_TCP6;
1019 break;
1020 default:
1021 return -ENOPROTOOPT;
1022 }
1023
1024 error = rpcb_v4_register(net, program, version,
1025 (const struct sockaddr *)&sin6, netid);
1026
1027 /*
1028 * User space didn't support rpcbind version 4, so we won't
1029 * use a PF_INET6 listener.
1030 */
1031 if (error == -EPROTONOSUPPORT)
1032 error = -EAFNOSUPPORT;
1033
1034 return error;
1035}
1036#endif /* IS_ENABLED(CONFIG_IPV6) */
1037
1038/*
1039 * Register a kernel RPC service via rpcbind version 4.
1040 *
1041 * Returns zero on success; a negative errno value is returned
1042 * if any error occurs.
1043 */
1044static int __svc_register(struct net *net, const char *progname,
1045 const u32 program, const u32 version,
1046 const int family,
1047 const unsigned short protocol,
1048 const unsigned short port)
1049{
1050 int error = -EAFNOSUPPORT;
1051
1052 switch (family) {
1053 case PF_INET:
1054 error = __svc_rpcb_register4(net, program, version,
1055 protocol, port);
1056 break;
1057#if IS_ENABLED(CONFIG_IPV6)
1058 case PF_INET6:
1059 error = __svc_rpcb_register6(net, program, version,
1060 protocol, port);
1061#endif
1062 }
1063
1064 trace_svc_register(progname, version, family, protocol, port, error);
1065 return error;
1066}
1067
1068int svc_rpcbind_set_version(struct net *net,
1069 const struct svc_program *progp,
1070 u32 version, int family,
1071 unsigned short proto,
1072 unsigned short port)
1073{
1074 return __svc_register(net, progp->pg_name, progp->pg_prog,
1075 version, family, proto, port);
1076
1077}
1078EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
1079
1080int svc_generic_rpcbind_set(struct net *net,
1081 const struct svc_program *progp,
1082 u32 version, int family,
1083 unsigned short proto,
1084 unsigned short port)
1085{
1086 const struct svc_version *vers = progp->pg_vers[version];
1087 int error;
1088
1089 if (vers == NULL)
1090 return 0;
1091
1092 if (vers->vs_hidden) {
1093 trace_svc_noregister(progp->pg_name, version, proto,
1094 port, family, 0);
1095 return 0;
1096 }
1097
1098 /*
1099 * Don't register a UDP port if we need congestion
1100 * control.
1101 */
1102 if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
1103 return 0;
1104
1105 error = svc_rpcbind_set_version(net, progp, version,
1106 family, proto, port);
1107
1108 return (vers->vs_rpcb_optnl) ? 0 : error;
1109}
1110EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
1111
1112/**
1113 * svc_register - register an RPC service with the local portmapper
1114 * @serv: svc_serv struct for the service to register
1115 * @net: net namespace for the service to register
1116 * @family: protocol family of service's listener socket
1117 * @proto: transport protocol number to advertise
1118 * @port: port to advertise
1119 *
1120 * Service is registered for any address in the passed-in protocol family
1121 */
1122int svc_register(const struct svc_serv *serv, struct net *net,
1123 const int family, const unsigned short proto,
1124 const unsigned short port)
1125{
1126 struct svc_program *progp;
1127 unsigned int i;
1128 int error = 0;
1129
1130 WARN_ON_ONCE(proto == 0 && port == 0);
1131 if (proto == 0 && port == 0)
1132 return -EINVAL;
1133
1134 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1135 for (i = 0; i < progp->pg_nvers; i++) {
1136
1137 error = progp->pg_rpcbind_set(net, progp, i,
1138 family, proto, port);
1139 if (error < 0) {
1140 printk(KERN_WARNING "svc: failed to register "
1141 "%sv%u RPC service (errno %d).\n",
1142 progp->pg_name, i, -error);
1143 break;
1144 }
1145 }
1146 }
1147
1148 return error;
1149}
1150
1151/*
1152 * If user space is running rpcbind, it should take the v4 UNSET
1153 * and clear everything for this [program, version]. If user space
1154 * is running portmap, it will reject the v4 UNSET, but won't have
1155 * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient
1156 * in this case to clear all existing entries for [program, version].
1157 */
1158static void __svc_unregister(struct net *net, const u32 program, const u32 version,
1159 const char *progname)
1160{
1161 int error;
1162
1163 error = rpcb_v4_register(net, program, version, NULL, "");
1164
1165 /*
1166 * User space didn't support rpcbind v4, so retry this
1167 * request with the legacy rpcbind v2 protocol.
1168 */
1169 if (error == -EPROTONOSUPPORT)
1170 error = rpcb_register(net, program, version, 0, 0);
1171
1172 trace_svc_unregister(progname, version, error);
1173}
1174
1175/*
1176 * All netids, bind addresses and ports registered for [program, version]
1177 * are removed from the local rpcbind database (if the service is not
1178 * hidden) to make way for a new instance of the service.
1179 *
1180 * The result of unregistration is reported via dprintk for those who want
1181 * verification of the result, but is otherwise not important.
1182 */
1183static void svc_unregister(const struct svc_serv *serv, struct net *net)
1184{
1185 struct sighand_struct *sighand;
1186 struct svc_program *progp;
1187 unsigned long flags;
1188 unsigned int i;
1189
1190 clear_thread_flag(TIF_SIGPENDING);
1191
1192 for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1193 for (i = 0; i < progp->pg_nvers; i++) {
1194 if (progp->pg_vers[i] == NULL)
1195 continue;
1196 if (progp->pg_vers[i]->vs_hidden)
1197 continue;
1198 __svc_unregister(net, progp->pg_prog, i, progp->pg_name);
1199 }
1200 }
1201
1202 rcu_read_lock();
1203 sighand = rcu_dereference(current->sighand);
1204 spin_lock_irqsave(&sighand->siglock, flags);
1205 recalc_sigpending();
1206 spin_unlock_irqrestore(&sighand->siglock, flags);
1207 rcu_read_unlock();
1208}
1209
1210/*
1211 * dprintk the given error with the address of the client that caused it.
1212 */
1213#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1214static __printf(2, 3)
1215void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
1216{
1217 struct va_format vaf;
1218 va_list args;
1219 char buf[RPC_MAX_ADDRBUFLEN];
1220
1221 va_start(args, fmt);
1222
1223 vaf.fmt = fmt;
1224 vaf.va = &args;
1225
1226 dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
1227
1228 va_end(args);
1229}
1230#else
1231static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
1232#endif
1233
1234__be32
1235svc_generic_init_request(struct svc_rqst *rqstp,
1236 const struct svc_program *progp,
1237 struct svc_process_info *ret)
1238{
1239 const struct svc_version *versp = NULL; /* compiler food */
1240 const struct svc_procedure *procp = NULL;
1241
1242 if (rqstp->rq_vers >= progp->pg_nvers )
1243 goto err_bad_vers;
1244 versp = progp->pg_vers[rqstp->rq_vers];
1245 if (!versp)
1246 goto err_bad_vers;
1247
1248 /*
1249 * Some protocol versions (namely NFSv4) require some form of
1250 * congestion control. (See RFC 7530 section 3.1 paragraph 2)
1251 * In other words, UDP is not allowed. We mark those when setting
1252 * up the svc_xprt, and verify that here.
1253 *
1254 * The spec is not very clear about what error should be returned
1255 * when someone tries to access a server that is listening on UDP
1256 * for lower versions. RPC_PROG_MISMATCH seems to be the closest
1257 * fit.
1258 */
1259 if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
1260 !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
1261 goto err_bad_vers;
1262
1263 if (rqstp->rq_proc >= versp->vs_nproc)
1264 goto err_bad_proc;
1265 rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
1266 if (!procp)
1267 goto err_bad_proc;
1268
1269 /* Initialize storage for argp and resp */
1270 memset(rqstp->rq_argp, 0, procp->pc_argzero);
1271 memset(rqstp->rq_resp, 0, procp->pc_ressize);
1272
1273 /* Bump per-procedure stats counter */
1274 this_cpu_inc(versp->vs_count[rqstp->rq_proc]);
1275
1276 ret->dispatch = versp->vs_dispatch;
1277 return rpc_success;
1278err_bad_vers:
1279 ret->mismatch.lovers = progp->pg_lovers;
1280 ret->mismatch.hivers = progp->pg_hivers;
1281 return rpc_prog_mismatch;
1282err_bad_proc:
1283 return rpc_proc_unavail;
1284}
1285EXPORT_SYMBOL_GPL(svc_generic_init_request);
1286
1287/*
1288 * Common routine for processing the RPC request.
1289 */
1290static int
1291svc_process_common(struct svc_rqst *rqstp)
1292{
1293 struct xdr_stream *xdr = &rqstp->rq_res_stream;
1294 struct svc_program *progp;
1295 const struct svc_procedure *procp = NULL;
1296 struct svc_serv *serv = rqstp->rq_server;
1297 struct svc_process_info process;
1298 enum svc_auth_status auth_res;
1299 unsigned int aoffset;
1300 int rc;
1301 __be32 *p;
1302
1303 /* Will be turned off only when NFSv4 Sessions are used */
1304 set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
1305 clear_bit(RQ_DROPME, &rqstp->rq_flags);
1306
1307 /* Construct the first words of the reply: */
1308 svcxdr_init_encode(rqstp);
1309 xdr_stream_encode_be32(xdr, rqstp->rq_xid);
1310 xdr_stream_encode_be32(xdr, rpc_reply);
1311
1312 p = xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 4);
1313 if (unlikely(!p))
1314 goto err_short_len;
1315 if (*p++ != cpu_to_be32(RPC_VERSION))
1316 goto err_bad_rpc;
1317
1318 xdr_stream_encode_be32(xdr, rpc_msg_accepted);
1319
1320 rqstp->rq_prog = be32_to_cpup(p++);
1321 rqstp->rq_vers = be32_to_cpup(p++);
1322 rqstp->rq_proc = be32_to_cpup(p);
1323
1324 for (progp = serv->sv_program; progp; progp = progp->pg_next)
1325 if (rqstp->rq_prog == progp->pg_prog)
1326 break;
1327
1328 /*
1329 * Decode auth data, and add verifier to reply buffer.
1330 * We do this before anything else in order to get a decent
1331 * auth verifier.
1332 */
1333 auth_res = svc_authenticate(rqstp);
1334 /* Also give the program a chance to reject this call: */
1335 if (auth_res == SVC_OK && progp)
1336 auth_res = progp->pg_authenticate(rqstp);
1337 trace_svc_authenticate(rqstp, auth_res);
1338 switch (auth_res) {
1339 case SVC_OK:
1340 break;
1341 case SVC_GARBAGE:
1342 goto err_garbage_args;
1343 case SVC_SYSERR:
1344 goto err_system_err;
1345 case SVC_DENIED:
1346 goto err_bad_auth;
1347 case SVC_CLOSE:
1348 goto close;
1349 case SVC_DROP:
1350 goto dropit;
1351 case SVC_COMPLETE:
1352 goto sendit;
1353 default:
1354 pr_warn_once("Unexpected svc_auth_status (%d)\n", auth_res);
1355 goto err_system_err;
1356 }
1357
1358 if (progp == NULL)
1359 goto err_bad_prog;
1360
1361 switch (progp->pg_init_request(rqstp, progp, &process)) {
1362 case rpc_success:
1363 break;
1364 case rpc_prog_unavail:
1365 goto err_bad_prog;
1366 case rpc_prog_mismatch:
1367 goto err_bad_vers;
1368 case rpc_proc_unavail:
1369 goto err_bad_proc;
1370 }
1371
1372 procp = rqstp->rq_procinfo;
1373 /* Should this check go into the dispatcher? */
1374 if (!procp || !procp->pc_func)
1375 goto err_bad_proc;
1376
1377 /* Syntactic check complete */
1378 serv->sv_stats->rpccnt++;
1379 trace_svc_process(rqstp, progp->pg_name);
1380
1381 aoffset = xdr_stream_pos(xdr);
1382
1383 /* un-reserve some of the out-queue now that we have a
1384 * better idea of reply size
1385 */
1386 if (procp->pc_xdrressize)
1387 svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1388
1389 /* Call the function that processes the request. */
1390 rc = process.dispatch(rqstp);
1391 if (procp->pc_release)
1392 procp->pc_release(rqstp);
1393 xdr_finish_decode(xdr);
1394
1395 if (!rc)
1396 goto dropit;
1397 if (rqstp->rq_auth_stat != rpc_auth_ok)
1398 goto err_bad_auth;
1399
1400 if (*rqstp->rq_accept_statp != rpc_success)
1401 xdr_truncate_encode(xdr, aoffset);
1402
1403 if (procp->pc_encode == NULL)
1404 goto dropit;
1405
1406 sendit:
1407 if (svc_authorise(rqstp))
1408 goto close_xprt;
1409 return 1; /* Caller can now send it */
1410
1411 dropit:
1412 svc_authorise(rqstp); /* doesn't hurt to call this twice */
1413 dprintk("svc: svc_process dropit\n");
1414 return 0;
1415
1416 close:
1417 svc_authorise(rqstp);
1418close_xprt:
1419 if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1420 svc_xprt_close(rqstp->rq_xprt);
1421 dprintk("svc: svc_process close\n");
1422 return 0;
1423
1424err_short_len:
1425 svc_printk(rqstp, "short len %u, dropping request\n",
1426 rqstp->rq_arg.len);
1427 goto close_xprt;
1428
1429err_bad_rpc:
1430 serv->sv_stats->rpcbadfmt++;
1431 xdr_stream_encode_u32(xdr, RPC_MSG_DENIED);
1432 xdr_stream_encode_u32(xdr, RPC_MISMATCH);
1433 /* Only RPCv2 supported */
1434 xdr_stream_encode_u32(xdr, RPC_VERSION);
1435 xdr_stream_encode_u32(xdr, RPC_VERSION);
1436 return 1; /* don't wrap */
1437
1438err_bad_auth:
1439 dprintk("svc: authentication failed (%d)\n",
1440 be32_to_cpu(rqstp->rq_auth_stat));
1441 serv->sv_stats->rpcbadauth++;
1442 /* Restore write pointer to location of reply status: */
1443 xdr_truncate_encode(xdr, XDR_UNIT * 2);
1444 xdr_stream_encode_u32(xdr, RPC_MSG_DENIED);
1445 xdr_stream_encode_u32(xdr, RPC_AUTH_ERROR);
1446 xdr_stream_encode_be32(xdr, rqstp->rq_auth_stat);
1447 goto sendit;
1448
1449err_bad_prog:
1450 dprintk("svc: unknown program %d\n", rqstp->rq_prog);
1451 serv->sv_stats->rpcbadfmt++;
1452 *rqstp->rq_accept_statp = rpc_prog_unavail;
1453 goto sendit;
1454
1455err_bad_vers:
1456 svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1457 rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
1458
1459 serv->sv_stats->rpcbadfmt++;
1460 *rqstp->rq_accept_statp = rpc_prog_mismatch;
1461
1462 /*
1463 * svc_authenticate() has already added the verifier and
1464 * advanced the stream just past rq_accept_statp.
1465 */
1466 xdr_stream_encode_u32(xdr, process.mismatch.lovers);
1467 xdr_stream_encode_u32(xdr, process.mismatch.hivers);
1468 goto sendit;
1469
1470err_bad_proc:
1471 svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
1472
1473 serv->sv_stats->rpcbadfmt++;
1474 *rqstp->rq_accept_statp = rpc_proc_unavail;
1475 goto sendit;
1476
1477err_garbage_args:
1478 svc_printk(rqstp, "failed to decode RPC header\n");
1479
1480 serv->sv_stats->rpcbadfmt++;
1481 *rqstp->rq_accept_statp = rpc_garbage_args;
1482 goto sendit;
1483
1484err_system_err:
1485 serv->sv_stats->rpcbadfmt++;
1486 *rqstp->rq_accept_statp = rpc_system_err;
1487 goto sendit;
1488}
1489
1490/**
1491 * svc_process - Execute one RPC transaction
1492 * @rqstp: RPC transaction context
1493 *
1494 */
1495void svc_process(struct svc_rqst *rqstp)
1496{
1497 struct kvec *resv = &rqstp->rq_res.head[0];
1498 __be32 *p;
1499
1500#if IS_ENABLED(CONFIG_FAIL_SUNRPC)
1501 if (!fail_sunrpc.ignore_server_disconnect &&
1502 should_fail(&fail_sunrpc.attr, 1))
1503 svc_xprt_deferred_close(rqstp->rq_xprt);
1504#endif
1505
1506 /*
1507 * Setup response xdr_buf.
1508 * Initially it has just one page
1509 */
1510 rqstp->rq_next_page = &rqstp->rq_respages[1];
1511 resv->iov_base = page_address(rqstp->rq_respages[0]);
1512 resv->iov_len = 0;
1513 rqstp->rq_res.pages = rqstp->rq_next_page;
1514 rqstp->rq_res.len = 0;
1515 rqstp->rq_res.page_base = 0;
1516 rqstp->rq_res.page_len = 0;
1517 rqstp->rq_res.buflen = PAGE_SIZE;
1518 rqstp->rq_res.tail[0].iov_base = NULL;
1519 rqstp->rq_res.tail[0].iov_len = 0;
1520
1521 svcxdr_init_decode(rqstp);
1522 p = xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2);
1523 if (unlikely(!p))
1524 goto out_drop;
1525 rqstp->rq_xid = *p++;
1526 if (unlikely(*p != rpc_call))
1527 goto out_baddir;
1528
1529 if (!svc_process_common(rqstp))
1530 goto out_drop;
1531 svc_send(rqstp);
1532 return;
1533
1534out_baddir:
1535 svc_printk(rqstp, "bad direction 0x%08x, dropping request\n",
1536 be32_to_cpu(*p));
1537 rqstp->rq_server->sv_stats->rpcbadfmt++;
1538out_drop:
1539 svc_drop(rqstp);
1540}
1541
1542#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1543/**
1544 * svc_process_bc - process a reverse-direction RPC request
1545 * @req: RPC request to be used for client-side processing
1546 * @rqstp: server-side execution context
1547 *
1548 */
1549void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp)
1550{
1551 struct rpc_task *task;
1552 int proc_error;
1553 struct rpc_timeout timeout;
1554
1555 /* Build the svc_rqst used by the common processing routine */
1556 rqstp->rq_xid = req->rq_xid;
1557 rqstp->rq_prot = req->rq_xprt->prot;
1558 rqstp->rq_bc_net = req->rq_xprt->xprt_net;
1559
1560 rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1561 memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1562 memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1563 memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1564
1565 /* Adjust the argument buffer length */
1566 rqstp->rq_arg.len = req->rq_private_buf.len;
1567 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1568 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1569 rqstp->rq_arg.page_len = 0;
1570 } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
1571 rqstp->rq_arg.page_len)
1572 rqstp->rq_arg.page_len = rqstp->rq_arg.len -
1573 rqstp->rq_arg.head[0].iov_len;
1574 else
1575 rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
1576 rqstp->rq_arg.page_len;
1577
1578 /* Reset the response buffer */
1579 rqstp->rq_res.head[0].iov_len = 0;
1580
1581 /*
1582 * Skip the XID and calldir fields because they've already
1583 * been processed by the caller.
1584 */
1585 svcxdr_init_decode(rqstp);
1586 if (!xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2))
1587 return;
1588
1589 /* Parse and execute the bc call */
1590 proc_error = svc_process_common(rqstp);
1591
1592 atomic_dec(&req->rq_xprt->bc_slot_count);
1593 if (!proc_error) {
1594 /* Processing error: drop the request */
1595 xprt_free_bc_request(req);
1596 return;
1597 }
1598 /* Finally, send the reply synchronously */
1599 if (rqstp->bc_to_initval > 0) {
1600 timeout.to_initval = rqstp->bc_to_initval;
1601 timeout.to_retries = rqstp->bc_to_retries;
1602 } else {
1603 timeout.to_initval = req->rq_xprt->timeout->to_initval;
1604 timeout.to_retries = req->rq_xprt->timeout->to_retries;
1605 }
1606 memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
1607 task = rpc_run_bc_task(req, &timeout);
1608
1609 if (IS_ERR(task))
1610 return;
1611
1612 WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
1613 rpc_put_task(task);
1614}
1615EXPORT_SYMBOL_GPL(svc_process_bc);
1616#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1617
1618/**
1619 * svc_max_payload - Return transport-specific limit on the RPC payload
1620 * @rqstp: RPC transaction context
1621 *
1622 * Returns the maximum number of payload bytes the current transport
1623 * allows.
1624 */
1625u32 svc_max_payload(const struct svc_rqst *rqstp)
1626{
1627 u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1628
1629 if (rqstp->rq_server->sv_max_payload < max)
1630 max = rqstp->rq_server->sv_max_payload;
1631 return max;
1632}
1633EXPORT_SYMBOL_GPL(svc_max_payload);
1634
1635/**
1636 * svc_proc_name - Return RPC procedure name in string form
1637 * @rqstp: svc_rqst to operate on
1638 *
1639 * Return value:
1640 * Pointer to a NUL-terminated string
1641 */
1642const char *svc_proc_name(const struct svc_rqst *rqstp)
1643{
1644 if (rqstp && rqstp->rq_procinfo)
1645 return rqstp->rq_procinfo->pc_name;
1646 return "unknown";
1647}
1648
1649
1650/**
1651 * svc_encode_result_payload - mark a range of bytes as a result payload
1652 * @rqstp: svc_rqst to operate on
1653 * @offset: payload's byte offset in rqstp->rq_res
1654 * @length: size of payload, in bytes
1655 *
1656 * Returns zero on success, or a negative errno if a permanent
1657 * error occurred.
1658 */
1659int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset,
1660 unsigned int length)
1661{
1662 return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset,
1663 length);
1664}
1665EXPORT_SYMBOL_GPL(svc_encode_result_payload);
1666
1667/**
1668 * svc_fill_write_vector - Construct data argument for VFS write call
1669 * @rqstp: svc_rqst to operate on
1670 * @payload: xdr_buf containing only the write data payload
1671 *
1672 * Fills in rqstp::rq_vec, and returns the number of elements.
1673 */
1674unsigned int svc_fill_write_vector(struct svc_rqst *rqstp,
1675 struct xdr_buf *payload)
1676{
1677 struct page **pages = payload->pages;
1678 struct kvec *first = payload->head;
1679 struct kvec *vec = rqstp->rq_vec;
1680 size_t total = payload->len;
1681 unsigned int i;
1682
1683 /* Some types of transport can present the write payload
1684 * entirely in rq_arg.pages. In this case, @first is empty.
1685 */
1686 i = 0;
1687 if (first->iov_len) {
1688 vec[i].iov_base = first->iov_base;
1689 vec[i].iov_len = min_t(size_t, total, first->iov_len);
1690 total -= vec[i].iov_len;
1691 ++i;
1692 }
1693
1694 while (total) {
1695 vec[i].iov_base = page_address(*pages);
1696 vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
1697 total -= vec[i].iov_len;
1698 ++i;
1699 ++pages;
1700 }
1701
1702 WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
1703 return i;
1704}
1705EXPORT_SYMBOL_GPL(svc_fill_write_vector);
1706
1707/**
1708 * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
1709 * @rqstp: svc_rqst to operate on
1710 * @first: buffer containing first section of pathname
1711 * @p: buffer containing remaining section of pathname
1712 * @total: total length of the pathname argument
1713 *
1714 * The VFS symlink API demands a NUL-terminated pathname in mapped memory.
1715 * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free
1716 * the returned string.
1717 */
1718char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
1719 void *p, size_t total)
1720{
1721 size_t len, remaining;
1722 char *result, *dst;
1723
1724 result = kmalloc(total + 1, GFP_KERNEL);
1725 if (!result)
1726 return ERR_PTR(-ESERVERFAULT);
1727
1728 dst = result;
1729 remaining = total;
1730
1731 len = min_t(size_t, total, first->iov_len);
1732 if (len) {
1733 memcpy(dst, first->iov_base, len);
1734 dst += len;
1735 remaining -= len;
1736 }
1737
1738 if (remaining) {
1739 len = min_t(size_t, remaining, PAGE_SIZE);
1740 memcpy(dst, p, len);
1741 dst += len;
1742 }
1743
1744 *dst = '\0';
1745
1746 /* Sanity check: Linux doesn't allow the pathname argument to
1747 * contain a NUL byte.
1748 */
1749 if (strlen(result) != total) {
1750 kfree(result);
1751 return ERR_PTR(-EINVAL);
1752 }
1753 return result;
1754}
1755EXPORT_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/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);