~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/svc.c

Version: ~ [ linux-5.18-rc6 ] ~ [ linux-5.17.6 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.38 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.114 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.192 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.241 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.277 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.312 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

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

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp