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 38 static 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 */ 45 enum { 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 58 struct 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 68 static struct svc_pool_map svc_pool_map = { 69 .mode = SVC_POOL_DEFAULT 70 }; 71 72 static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */ 73 74 static int 75 param_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 99 out: 100 mutex_unlock(&svc_pool_map_mutex); 101 return err; 102 } 103 104 static int 105 param_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 } 123 124 module_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 */ 131 static int 132 svc_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 */ 163 static int 164 svc_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; 174 175 fail_free: 176 kfree(m->to_pool); 177 m->to_pool = NULL; 178 fail: 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 */ 186 static int 187 svc_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 */ 214 static int 215 svc_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 */ 246 static unsigned int 247 svc_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 */ 295 static void 296 svc_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 } 314 315 static 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 */ 331 static inline void 332 svc_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 */ 370 struct 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 } 390 391 int 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 } 403 EXPORT_SYMBOL_GPL(svc_rpcb_setup); 404 405 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net) 406 { 407 svc_unregister(serv, net); 408 rpcb_put_local(net); 409 } 410 EXPORT_SYMBOL_GPL(svc_rpcb_cleanup); 411 412 static 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 } 428 429 int 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 } 435 EXPORT_SYMBOL_GPL(svc_bind); 436 437 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 438 static void 439 __svc_init_bc(struct svc_serv *serv) 440 { 441 lwq_init(&serv->sv_cb_list); 442 } 443 #else 444 static void 445 __svc_init_bc(struct svc_serv *serv) 446 { 447 } 448 #endif 449 450 /* 451 * Create an RPC service 452 */ 453 static struct svc_serv * 454 __svc_create(struct svc_program *prog, struct svc_stat *stats, 455 unsigned int bufsize, int npools, 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 = 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 */ 529 struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize, 530 int (*threadfn)(void *data)) 531 { 532 return __svc_create(prog, NULL, bufsize, 1, threadfn); 533 } 534 EXPORT_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 * @stats: the stats struct if desired 540 * @bufsize: maximum message size for @prog 541 * @threadfn: a function to service RPC requests for @prog 542 * 543 * Returns an instantiated struct svc_serv object or NULL. 544 */ 545 struct svc_serv *svc_create_pooled(struct svc_program *prog, 546 struct svc_stat *stats, 547 unsigned int bufsize, 548 int (*threadfn)(void *data)) 549 { 550 struct svc_serv *serv; 551 unsigned int npools = svc_pool_map_get(); 552 553 serv = __svc_create(prog, stats, bufsize, npools, threadfn); 554 if (!serv) 555 goto out_err; 556 return serv; 557 out_err: 558 svc_pool_map_put(npools); 559 return NULL; 560 } 561 EXPORT_SYMBOL_GPL(svc_create_pooled); 562 563 /* 564 * Destroy an RPC service. Should be called with appropriate locking to 565 * protect sv_permsocks and sv_tempsocks. 566 */ 567 void 568 svc_destroy(struct svc_serv **servp) 569 { 570 struct svc_serv *serv = *servp; 571 unsigned int i; 572 573 *servp = NULL; 574 575 dprintk("svc: svc_destroy(%s)\n", serv->sv_program->pg_name); 576 timer_shutdown_sync(&serv->sv_temptimer); 577 578 /* 579 * Remaining transports at this point are not expected. 580 */ 581 WARN_ONCE(!list_empty(&serv->sv_permsocks), 582 "SVC: permsocks remain for %s\n", serv->sv_program->pg_name); 583 WARN_ONCE(!list_empty(&serv->sv_tempsocks), 584 "SVC: tempsocks remain for %s\n", serv->sv_program->pg_name); 585 586 cache_clean_deferred(serv); 587 588 svc_pool_map_put(serv->sv_nrpools); 589 590 for (i = 0; i < serv->sv_nrpools; i++) { 591 struct svc_pool *pool = &serv->sv_pools[i]; 592 593 percpu_counter_destroy(&pool->sp_messages_arrived); 594 percpu_counter_destroy(&pool->sp_sockets_queued); 595 percpu_counter_destroy(&pool->sp_threads_woken); 596 } 597 kfree(serv->sv_pools); 598 kfree(serv); 599 } 600 EXPORT_SYMBOL_GPL(svc_destroy); 601 602 static bool 603 svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node) 604 { 605 unsigned long pages, ret; 606 607 /* bc_xprt uses fore channel allocated buffers */ 608 if (svc_is_backchannel(rqstp)) 609 return true; 610 611 pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply. 612 * We assume one is at most one page 613 */ 614 WARN_ON_ONCE(pages > RPCSVC_MAXPAGES); 615 if (pages > RPCSVC_MAXPAGES) 616 pages = RPCSVC_MAXPAGES; 617 618 ret = alloc_pages_bulk_array_node(GFP_KERNEL, node, pages, 619 rqstp->rq_pages); 620 return ret == pages; 621 } 622 623 /* 624 * Release an RPC server buffer 625 */ 626 static void 627 svc_release_buffer(struct svc_rqst *rqstp) 628 { 629 unsigned int i; 630 631 for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++) 632 if (rqstp->rq_pages[i]) 633 put_page(rqstp->rq_pages[i]); 634 } 635 636 struct svc_rqst * 637 svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node) 638 { 639 struct svc_rqst *rqstp; 640 641 rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node); 642 if (!rqstp) 643 return rqstp; 644 645 folio_batch_init(&rqstp->rq_fbatch); 646 647 rqstp->rq_server = serv; 648 rqstp->rq_pool = pool; 649 650 rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0); 651 if (!rqstp->rq_scratch_page) 652 goto out_enomem; 653 654 rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node); 655 if (!rqstp->rq_argp) 656 goto out_enomem; 657 658 rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node); 659 if (!rqstp->rq_resp) 660 goto out_enomem; 661 662 if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node)) 663 goto out_enomem; 664 665 return rqstp; 666 out_enomem: 667 svc_rqst_free(rqstp); 668 return NULL; 669 } 670 EXPORT_SYMBOL_GPL(svc_rqst_alloc); 671 672 static struct svc_rqst * 673 svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) 674 { 675 struct svc_rqst *rqstp; 676 677 rqstp = svc_rqst_alloc(serv, pool, node); 678 if (!rqstp) 679 return ERR_PTR(-ENOMEM); 680 681 spin_lock_bh(&serv->sv_lock); 682 serv->sv_nrthreads += 1; 683 spin_unlock_bh(&serv->sv_lock); 684 685 atomic_inc(&pool->sp_nrthreads); 686 687 /* Protected by whatever lock the service uses when calling 688 * svc_set_num_threads() 689 */ 690 list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads); 691 692 return rqstp; 693 } 694 695 /** 696 * svc_pool_wake_idle_thread - Awaken an idle thread in @pool 697 * @pool: service thread pool 698 * 699 * Can be called from soft IRQ or process context. Finding an idle 700 * service thread and marking it BUSY is atomic with respect to 701 * other calls to svc_pool_wake_idle_thread(). 702 * 703 */ 704 void svc_pool_wake_idle_thread(struct svc_pool *pool) 705 { 706 struct svc_rqst *rqstp; 707 struct llist_node *ln; 708 709 rcu_read_lock(); 710 ln = READ_ONCE(pool->sp_idle_threads.first); 711 if (ln) { 712 rqstp = llist_entry(ln, struct svc_rqst, rq_idle); 713 WRITE_ONCE(rqstp->rq_qtime, ktime_get()); 714 if (!task_is_running(rqstp->rq_task)) { 715 wake_up_process(rqstp->rq_task); 716 trace_svc_wake_up(rqstp->rq_task->pid); 717 percpu_counter_inc(&pool->sp_threads_woken); 718 } 719 rcu_read_unlock(); 720 return; 721 } 722 rcu_read_unlock(); 723 724 } 725 EXPORT_SYMBOL_GPL(svc_pool_wake_idle_thread); 726 727 static struct svc_pool * 728 svc_pool_next(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state) 729 { 730 return pool ? pool : &serv->sv_pools[(*state)++ % serv->sv_nrpools]; 731 } 732 733 static struct svc_pool * 734 svc_pool_victim(struct svc_serv *serv, struct svc_pool *target_pool, 735 unsigned int *state) 736 { 737 struct svc_pool *pool; 738 unsigned int i; 739 740 retry: 741 pool = target_pool; 742 743 if (pool != NULL) { 744 if (atomic_inc_not_zero(&pool->sp_nrthreads)) 745 goto found_pool; 746 return NULL; 747 } else { 748 for (i = 0; i < serv->sv_nrpools; i++) { 749 pool = &serv->sv_pools[--(*state) % serv->sv_nrpools]; 750 if (atomic_inc_not_zero(&pool->sp_nrthreads)) 751 goto found_pool; 752 } 753 return NULL; 754 } 755 756 found_pool: 757 set_bit(SP_VICTIM_REMAINS, &pool->sp_flags); 758 set_bit(SP_NEED_VICTIM, &pool->sp_flags); 759 if (!atomic_dec_and_test(&pool->sp_nrthreads)) 760 return pool; 761 /* Nothing left in this pool any more */ 762 clear_bit(SP_NEED_VICTIM, &pool->sp_flags); 763 clear_bit(SP_VICTIM_REMAINS, &pool->sp_flags); 764 goto retry; 765 } 766 767 static int 768 svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) 769 { 770 struct svc_rqst *rqstp; 771 struct task_struct *task; 772 struct svc_pool *chosen_pool; 773 unsigned int state = serv->sv_nrthreads-1; 774 int node; 775 776 do { 777 nrservs--; 778 chosen_pool = svc_pool_next(serv, pool, &state); 779 node = svc_pool_map_get_node(chosen_pool->sp_id); 780 781 rqstp = svc_prepare_thread(serv, chosen_pool, node); 782 if (IS_ERR(rqstp)) 783 return PTR_ERR(rqstp); 784 task = kthread_create_on_node(serv->sv_threadfn, rqstp, 785 node, "%s", serv->sv_name); 786 if (IS_ERR(task)) { 787 svc_exit_thread(rqstp); 788 return PTR_ERR(task); 789 } 790 791 rqstp->rq_task = task; 792 if (serv->sv_nrpools > 1) 793 svc_pool_map_set_cpumask(task, chosen_pool->sp_id); 794 795 svc_sock_update_bufs(serv); 796 wake_up_process(task); 797 } while (nrservs > 0); 798 799 return 0; 800 } 801 802 static int 803 svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) 804 { 805 unsigned int state = serv->sv_nrthreads-1; 806 struct svc_pool *victim; 807 808 do { 809 victim = svc_pool_victim(serv, pool, &state); 810 if (!victim) 811 break; 812 svc_pool_wake_idle_thread(victim); 813 wait_on_bit(&victim->sp_flags, SP_VICTIM_REMAINS, 814 TASK_IDLE); 815 nrservs++; 816 } while (nrservs < 0); 817 return 0; 818 } 819 820 /** 821 * svc_set_num_threads - adjust number of threads per RPC service 822 * @serv: RPC service to adjust 823 * @pool: Specific pool from which to choose threads, or NULL 824 * @nrservs: New number of threads for @serv (0 or less means kill all threads) 825 * 826 * Create or destroy threads to make the number of threads for @serv the 827 * given number. If @pool is non-NULL, change only threads in that pool; 828 * otherwise, round-robin between all pools for @serv. @serv's 829 * sv_nrthreads is adjusted for each thread created or destroyed. 830 * 831 * Caller must ensure mutual exclusion between this and server startup or 832 * shutdown. 833 * 834 * Returns zero on success or a negative errno if an error occurred while 835 * starting a thread. 836 */ 837 int 838 svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) 839 { 840 if (!pool) 841 nrservs -= serv->sv_nrthreads; 842 else 843 nrservs -= atomic_read(&pool->sp_nrthreads); 844 845 if (nrservs > 0) 846 return svc_start_kthreads(serv, pool, nrservs); 847 if (nrservs < 0) 848 return svc_stop_kthreads(serv, pool, nrservs); 849 return 0; 850 } 851 EXPORT_SYMBOL_GPL(svc_set_num_threads); 852 853 /** 854 * svc_rqst_replace_page - Replace one page in rq_pages[] 855 * @rqstp: svc_rqst with pages to replace 856 * @page: replacement page 857 * 858 * When replacing a page in rq_pages, batch the release of the 859 * replaced pages to avoid hammering the page allocator. 860 * 861 * Return values: 862 * %true: page replaced 863 * %false: array bounds checking failed 864 */ 865 bool svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page) 866 { 867 struct page **begin = rqstp->rq_pages; 868 struct page **end = &rqstp->rq_pages[RPCSVC_MAXPAGES]; 869 870 if (unlikely(rqstp->rq_next_page < begin || rqstp->rq_next_page > end)) { 871 trace_svc_replace_page_err(rqstp); 872 return false; 873 } 874 875 if (*rqstp->rq_next_page) { 876 if (!folio_batch_add(&rqstp->rq_fbatch, 877 page_folio(*rqstp->rq_next_page))) 878 __folio_batch_release(&rqstp->rq_fbatch); 879 } 880 881 get_page(page); 882 *(rqstp->rq_next_page++) = page; 883 return true; 884 } 885 EXPORT_SYMBOL_GPL(svc_rqst_replace_page); 886 887 /** 888 * svc_rqst_release_pages - Release Reply buffer pages 889 * @rqstp: RPC transaction context 890 * 891 * Release response pages that might still be in flight after 892 * svc_send, and any spliced filesystem-owned pages. 893 */ 894 void svc_rqst_release_pages(struct svc_rqst *rqstp) 895 { 896 int i, count = rqstp->rq_next_page - rqstp->rq_respages; 897 898 if (count) { 899 release_pages(rqstp->rq_respages, count); 900 for (i = 0; i < count; i++) 901 rqstp->rq_respages[i] = NULL; 902 } 903 } 904 905 /* 906 * Called from a server thread as it's exiting. Caller must hold the "service 907 * mutex" for the service. 908 */ 909 void 910 svc_rqst_free(struct svc_rqst *rqstp) 911 { 912 folio_batch_release(&rqstp->rq_fbatch); 913 svc_release_buffer(rqstp); 914 if (rqstp->rq_scratch_page) 915 put_page(rqstp->rq_scratch_page); 916 kfree(rqstp->rq_resp); 917 kfree(rqstp->rq_argp); 918 kfree(rqstp->rq_auth_data); 919 kfree_rcu(rqstp, rq_rcu_head); 920 } 921 EXPORT_SYMBOL_GPL(svc_rqst_free); 922 923 void 924 svc_exit_thread(struct svc_rqst *rqstp) 925 { 926 struct svc_serv *serv = rqstp->rq_server; 927 struct svc_pool *pool = rqstp->rq_pool; 928 929 list_del_rcu(&rqstp->rq_all); 930 931 atomic_dec(&pool->sp_nrthreads); 932 933 spin_lock_bh(&serv->sv_lock); 934 serv->sv_nrthreads -= 1; 935 spin_unlock_bh(&serv->sv_lock); 936 svc_sock_update_bufs(serv); 937 938 svc_rqst_free(rqstp); 939 940 clear_and_wake_up_bit(SP_VICTIM_REMAINS, &pool->sp_flags); 941 } 942 EXPORT_SYMBOL_GPL(svc_exit_thread); 943 944 /* 945 * Register an "inet" protocol family netid with the local 946 * rpcbind daemon via an rpcbind v4 SET request. 947 * 948 * No netconfig infrastructure is available in the kernel, so 949 * we map IP_ protocol numbers to netids by hand. 950 * 951 * Returns zero on success; a negative errno value is returned 952 * if any error occurs. 953 */ 954 static int __svc_rpcb_register4(struct net *net, const u32 program, 955 const u32 version, 956 const unsigned short protocol, 957 const unsigned short port) 958 { 959 const struct sockaddr_in sin = { 960 .sin_family = AF_INET, 961 .sin_addr.s_addr = htonl(INADDR_ANY), 962 .sin_port = htons(port), 963 }; 964 const char *netid; 965 int error; 966 967 switch (protocol) { 968 case IPPROTO_UDP: 969 netid = RPCBIND_NETID_UDP; 970 break; 971 case IPPROTO_TCP: 972 netid = RPCBIND_NETID_TCP; 973 break; 974 default: 975 return -ENOPROTOOPT; 976 } 977 978 error = rpcb_v4_register(net, program, version, 979 (const struct sockaddr *)&sin, netid); 980 981 /* 982 * User space didn't support rpcbind v4, so retry this 983 * registration request with the legacy rpcbind v2 protocol. 984 */ 985 if (error == -EPROTONOSUPPORT) 986 error = rpcb_register(net, program, version, protocol, port); 987 988 return error; 989 } 990 991 #if IS_ENABLED(CONFIG_IPV6) 992 /* 993 * Register an "inet6" protocol family netid with the local 994 * rpcbind daemon via an rpcbind v4 SET request. 995 * 996 * No netconfig infrastructure is available in the kernel, so 997 * we map IP_ protocol numbers to netids by hand. 998 * 999 * Returns zero on success; a negative errno value is returned 1000 * if any error occurs. 1001 */ 1002 static int __svc_rpcb_register6(struct net *net, const u32 program, 1003 const u32 version, 1004 const unsigned short protocol, 1005 const unsigned short port) 1006 { 1007 const struct sockaddr_in6 sin6 = { 1008 .sin6_family = AF_INET6, 1009 .sin6_addr = IN6ADDR_ANY_INIT, 1010 .sin6_port = htons(port), 1011 }; 1012 const char *netid; 1013 int error; 1014 1015 switch (protocol) { 1016 case IPPROTO_UDP: 1017 netid = RPCBIND_NETID_UDP6; 1018 break; 1019 case IPPROTO_TCP: 1020 netid = RPCBIND_NETID_TCP6; 1021 break; 1022 default: 1023 return -ENOPROTOOPT; 1024 } 1025 1026 error = rpcb_v4_register(net, program, version, 1027 (const struct sockaddr *)&sin6, netid); 1028 1029 /* 1030 * User space didn't support rpcbind version 4, so we won't 1031 * use a PF_INET6 listener. 1032 */ 1033 if (error == -EPROTONOSUPPORT) 1034 error = -EAFNOSUPPORT; 1035 1036 return error; 1037 } 1038 #endif /* IS_ENABLED(CONFIG_IPV6) */ 1039 1040 /* 1041 * Register a kernel RPC service via rpcbind version 4. 1042 * 1043 * Returns zero on success; a negative errno value is returned 1044 * if any error occurs. 1045 */ 1046 static int __svc_register(struct net *net, const char *progname, 1047 const u32 program, const u32 version, 1048 const int family, 1049 const unsigned short protocol, 1050 const unsigned short port) 1051 { 1052 int error = -EAFNOSUPPORT; 1053 1054 switch (family) { 1055 case PF_INET: 1056 error = __svc_rpcb_register4(net, program, version, 1057 protocol, port); 1058 break; 1059 #if IS_ENABLED(CONFIG_IPV6) 1060 case PF_INET6: 1061 error = __svc_rpcb_register6(net, program, version, 1062 protocol, port); 1063 #endif 1064 } 1065 1066 trace_svc_register(progname, version, family, protocol, port, error); 1067 return error; 1068 } 1069 1070 int svc_rpcbind_set_version(struct net *net, 1071 const struct svc_program *progp, 1072 u32 version, int family, 1073 unsigned short proto, 1074 unsigned short port) 1075 { 1076 return __svc_register(net, progp->pg_name, progp->pg_prog, 1077 version, family, proto, port); 1078 1079 } 1080 EXPORT_SYMBOL_GPL(svc_rpcbind_set_version); 1081 1082 int svc_generic_rpcbind_set(struct net *net, 1083 const struct svc_program *progp, 1084 u32 version, int family, 1085 unsigned short proto, 1086 unsigned short port) 1087 { 1088 const struct svc_version *vers = progp->pg_vers[version]; 1089 int error; 1090 1091 if (vers == NULL) 1092 return 0; 1093 1094 if (vers->vs_hidden) { 1095 trace_svc_noregister(progp->pg_name, version, proto, 1096 port, family, 0); 1097 return 0; 1098 } 1099 1100 /* 1101 * Don't register a UDP port if we need congestion 1102 * control. 1103 */ 1104 if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP) 1105 return 0; 1106 1107 error = svc_rpcbind_set_version(net, progp, version, 1108 family, proto, port); 1109 1110 return (vers->vs_rpcb_optnl) ? 0 : error; 1111 } 1112 EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set); 1113 1114 /** 1115 * svc_register - register an RPC service with the local portmapper 1116 * @serv: svc_serv struct for the service to register 1117 * @net: net namespace for the service to register 1118 * @family: protocol family of service's listener socket 1119 * @proto: transport protocol number to advertise 1120 * @port: port to advertise 1121 * 1122 * Service is registered for any address in the passed-in protocol family 1123 */ 1124 int svc_register(const struct svc_serv *serv, struct net *net, 1125 const int family, const unsigned short proto, 1126 const unsigned short port) 1127 { 1128 struct svc_program *progp; 1129 unsigned int i; 1130 int error = 0; 1131 1132 WARN_ON_ONCE(proto == 0 && port == 0); 1133 if (proto == 0 && port == 0) 1134 return -EINVAL; 1135 1136 for (progp = serv->sv_program; progp; progp = progp->pg_next) { 1137 for (i = 0; i < progp->pg_nvers; i++) { 1138 1139 error = progp->pg_rpcbind_set(net, progp, i, 1140 family, proto, port); 1141 if (error < 0) { 1142 printk(KERN_WARNING "svc: failed to register " 1143 "%sv%u RPC service (errno %d).\n", 1144 progp->pg_name, i, -error); 1145 break; 1146 } 1147 } 1148 } 1149 1150 return error; 1151 } 1152 1153 /* 1154 * If user space is running rpcbind, it should take the v4 UNSET 1155 * and clear everything for this [program, version]. If user space 1156 * is running portmap, it will reject the v4 UNSET, but won't have 1157 * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient 1158 * in this case to clear all existing entries for [program, version]. 1159 */ 1160 static void __svc_unregister(struct net *net, const u32 program, const u32 version, 1161 const char *progname) 1162 { 1163 int error; 1164 1165 error = rpcb_v4_register(net, program, version, NULL, ""); 1166 1167 /* 1168 * User space didn't support rpcbind v4, so retry this 1169 * request with the legacy rpcbind v2 protocol. 1170 */ 1171 if (error == -EPROTONOSUPPORT) 1172 error = rpcb_register(net, program, version, 0, 0); 1173 1174 trace_svc_unregister(progname, version, error); 1175 } 1176 1177 /* 1178 * All netids, bind addresses and ports registered for [program, version] 1179 * are removed from the local rpcbind database (if the service is not 1180 * hidden) to make way for a new instance of the service. 1181 * 1182 * The result of unregistration is reported via dprintk for those who want 1183 * verification of the result, but is otherwise not important. 1184 */ 1185 static void svc_unregister(const struct svc_serv *serv, struct net *net) 1186 { 1187 struct sighand_struct *sighand; 1188 struct svc_program *progp; 1189 unsigned long flags; 1190 unsigned int i; 1191 1192 clear_thread_flag(TIF_SIGPENDING); 1193 1194 for (progp = serv->sv_program; progp; progp = progp->pg_next) { 1195 for (i = 0; i < progp->pg_nvers; i++) { 1196 if (progp->pg_vers[i] == NULL) 1197 continue; 1198 if (progp->pg_vers[i]->vs_hidden) 1199 continue; 1200 __svc_unregister(net, progp->pg_prog, i, progp->pg_name); 1201 } 1202 } 1203 1204 rcu_read_lock(); 1205 sighand = rcu_dereference(current->sighand); 1206 spin_lock_irqsave(&sighand->siglock, flags); 1207 recalc_sigpending(); 1208 spin_unlock_irqrestore(&sighand->siglock, flags); 1209 rcu_read_unlock(); 1210 } 1211 1212 /* 1213 * dprintk the given error with the address of the client that caused it. 1214 */ 1215 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 1216 static __printf(2, 3) 1217 void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) 1218 { 1219 struct va_format vaf; 1220 va_list args; 1221 char buf[RPC_MAX_ADDRBUFLEN]; 1222 1223 va_start(args, fmt); 1224 1225 vaf.fmt = fmt; 1226 vaf.va = &args; 1227 1228 dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf); 1229 1230 va_end(args); 1231 } 1232 #else 1233 static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {} 1234 #endif 1235 1236 __be32 1237 svc_generic_init_request(struct svc_rqst *rqstp, 1238 const struct svc_program *progp, 1239 struct svc_process_info *ret) 1240 { 1241 const struct svc_version *versp = NULL; /* compiler food */ 1242 const struct svc_procedure *procp = NULL; 1243 1244 if (rqstp->rq_vers >= progp->pg_nvers ) 1245 goto err_bad_vers; 1246 versp = progp->pg_vers[rqstp->rq_vers]; 1247 if (!versp) 1248 goto err_bad_vers; 1249 1250 /* 1251 * Some protocol versions (namely NFSv4) require some form of 1252 * congestion control. (See RFC 7530 section 3.1 paragraph 2) 1253 * In other words, UDP is not allowed. We mark those when setting 1254 * up the svc_xprt, and verify that here. 1255 * 1256 * The spec is not very clear about what error should be returned 1257 * when someone tries to access a server that is listening on UDP 1258 * for lower versions. RPC_PROG_MISMATCH seems to be the closest 1259 * fit. 1260 */ 1261 if (versp->vs_need_cong_ctrl && rqstp->rq_xprt && 1262 !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags)) 1263 goto err_bad_vers; 1264 1265 if (rqstp->rq_proc >= versp->vs_nproc) 1266 goto err_bad_proc; 1267 rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_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; 1278 err_bad_vers: 1279 ret->mismatch.lovers = progp->pg_lovers; 1280 ret->mismatch.hivers = progp->pg_hivers; 1281 return rpc_prog_mismatch; 1282 err_bad_proc: 1283 return rpc_proc_unavail; 1284 } 1285 EXPORT_SYMBOL_GPL(svc_generic_init_request); 1286 1287 /* 1288 * Common routine for processing the RPC request. 1289 */ 1290 static int 1291 svc_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 if (serv->sv_stats) 1379 serv->sv_stats->rpccnt++; 1380 trace_svc_process(rqstp, progp->pg_name); 1381 1382 aoffset = xdr_stream_pos(xdr); 1383 1384 /* un-reserve some of the out-queue now that we have a 1385 * better idea of reply size 1386 */ 1387 if (procp->pc_xdrressize) 1388 svc_reserve_auth(rqstp, procp->pc_xdrressize<<2); 1389 1390 /* Call the function that processes the request. */ 1391 rc = process.dispatch(rqstp); 1392 if (procp->pc_release) 1393 procp->pc_release(rqstp); 1394 xdr_finish_decode(xdr); 1395 1396 if (!rc) 1397 goto dropit; 1398 if (rqstp->rq_auth_stat != rpc_auth_ok) 1399 goto err_bad_auth; 1400 1401 if (*rqstp->rq_accept_statp != rpc_success) 1402 xdr_truncate_encode(xdr, aoffset); 1403 1404 if (procp->pc_encode == NULL) 1405 goto dropit; 1406 1407 sendit: 1408 if (svc_authorise(rqstp)) 1409 goto close_xprt; 1410 return 1; /* Caller can now send it */ 1411 1412 dropit: 1413 svc_authorise(rqstp); /* doesn't hurt to call this twice */ 1414 dprintk("svc: svc_process dropit\n"); 1415 return 0; 1416 1417 close: 1418 svc_authorise(rqstp); 1419 close_xprt: 1420 if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags)) 1421 svc_xprt_close(rqstp->rq_xprt); 1422 dprintk("svc: svc_process close\n"); 1423 return 0; 1424 1425 err_short_len: 1426 svc_printk(rqstp, "short len %u, dropping request\n", 1427 rqstp->rq_arg.len); 1428 goto close_xprt; 1429 1430 err_bad_rpc: 1431 if (serv->sv_stats) 1432 serv->sv_stats->rpcbadfmt++; 1433 xdr_stream_encode_u32(xdr, RPC_MSG_DENIED); 1434 xdr_stream_encode_u32(xdr, RPC_MISMATCH); 1435 /* Only RPCv2 supported */ 1436 xdr_stream_encode_u32(xdr, RPC_VERSION); 1437 xdr_stream_encode_u32(xdr, RPC_VERSION); 1438 return 1; /* don't wrap */ 1439 1440 err_bad_auth: 1441 dprintk("svc: authentication failed (%d)\n", 1442 be32_to_cpu(rqstp->rq_auth_stat)); 1443 if (serv->sv_stats) 1444 serv->sv_stats->rpcbadauth++; 1445 /* Restore write pointer to location of reply status: */ 1446 xdr_truncate_encode(xdr, XDR_UNIT * 2); 1447 xdr_stream_encode_u32(xdr, RPC_MSG_DENIED); 1448 xdr_stream_encode_u32(xdr, RPC_AUTH_ERROR); 1449 xdr_stream_encode_be32(xdr, rqstp->rq_auth_stat); 1450 goto sendit; 1451 1452 err_bad_prog: 1453 dprintk("svc: unknown program %d\n", rqstp->rq_prog); 1454 if (serv->sv_stats) 1455 serv->sv_stats->rpcbadfmt++; 1456 *rqstp->rq_accept_statp = rpc_prog_unavail; 1457 goto sendit; 1458 1459 err_bad_vers: 1460 svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n", 1461 rqstp->rq_vers, rqstp->rq_prog, progp->pg_name); 1462 1463 if (serv->sv_stats) 1464 serv->sv_stats->rpcbadfmt++; 1465 *rqstp->rq_accept_statp = rpc_prog_mismatch; 1466 1467 /* 1468 * svc_authenticate() has already added the verifier and 1469 * advanced the stream just past rq_accept_statp. 1470 */ 1471 xdr_stream_encode_u32(xdr, process.mismatch.lovers); 1472 xdr_stream_encode_u32(xdr, process.mismatch.hivers); 1473 goto sendit; 1474 1475 err_bad_proc: 1476 svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc); 1477 1478 if (serv->sv_stats) 1479 serv->sv_stats->rpcbadfmt++; 1480 *rqstp->rq_accept_statp = rpc_proc_unavail; 1481 goto sendit; 1482 1483 err_garbage_args: 1484 svc_printk(rqstp, "failed to decode RPC header\n"); 1485 1486 if (serv->sv_stats) 1487 serv->sv_stats->rpcbadfmt++; 1488 *rqstp->rq_accept_statp = rpc_garbage_args; 1489 goto sendit; 1490 1491 err_system_err: 1492 if (serv->sv_stats) 1493 serv->sv_stats->rpcbadfmt++; 1494 *rqstp->rq_accept_statp = rpc_system_err; 1495 goto sendit; 1496 } 1497 1498 /** 1499 * svc_process - Execute one RPC transaction 1500 * @rqstp: RPC transaction context 1501 * 1502 */ 1503 void svc_process(struct svc_rqst *rqstp) 1504 { 1505 struct kvec *resv = &rqstp->rq_res.head[0]; 1506 __be32 *p; 1507 1508 #if IS_ENABLED(CONFIG_FAIL_SUNRPC) 1509 if (!fail_sunrpc.ignore_server_disconnect && 1510 should_fail(&fail_sunrpc.attr, 1)) 1511 svc_xprt_deferred_close(rqstp->rq_xprt); 1512 #endif 1513 1514 /* 1515 * Setup response xdr_buf. 1516 * Initially it has just one page 1517 */ 1518 rqstp->rq_next_page = &rqstp->rq_respages[1]; 1519 resv->iov_base = page_address(rqstp->rq_respages[0]); 1520 resv->iov_len = 0; 1521 rqstp->rq_res.pages = rqstp->rq_next_page; 1522 rqstp->rq_res.len = 0; 1523 rqstp->rq_res.page_base = 0; 1524 rqstp->rq_res.page_len = 0; 1525 rqstp->rq_res.buflen = PAGE_SIZE; 1526 rqstp->rq_res.tail[0].iov_base = NULL; 1527 rqstp->rq_res.tail[0].iov_len = 0; 1528 1529 svcxdr_init_decode(rqstp); 1530 p = xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2); 1531 if (unlikely(!p)) 1532 goto out_drop; 1533 rqstp->rq_xid = *p++; 1534 if (unlikely(*p != rpc_call)) 1535 goto out_baddir; 1536 1537 if (!svc_process_common(rqstp)) 1538 goto out_drop; 1539 svc_send(rqstp); 1540 return; 1541 1542 out_baddir: 1543 svc_printk(rqstp, "bad direction 0x%08x, dropping request\n", 1544 be32_to_cpu(*p)); 1545 if (rqstp->rq_server->sv_stats) 1546 rqstp->rq_server->sv_stats->rpcbadfmt++; 1547 out_drop: 1548 svc_drop(rqstp); 1549 } 1550 1551 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1552 /** 1553 * svc_process_bc - process a reverse-direction RPC request 1554 * @req: RPC request to be used for client-side processing 1555 * @rqstp: server-side execution context 1556 * 1557 */ 1558 void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp) 1559 { 1560 struct rpc_timeout timeout = { 1561 .to_increment = 0, 1562 }; 1563 struct rpc_task *task; 1564 int proc_error; 1565 1566 /* Build the svc_rqst used by the common processing routine */ 1567 rqstp->rq_xid = req->rq_xid; 1568 rqstp->rq_prot = req->rq_xprt->prot; 1569 rqstp->rq_bc_net = req->rq_xprt->xprt_net; 1570 1571 rqstp->rq_addrlen = sizeof(req->rq_xprt->addr); 1572 memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen); 1573 memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg)); 1574 memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res)); 1575 1576 /* Adjust the argument buffer length */ 1577 rqstp->rq_arg.len = req->rq_private_buf.len; 1578 if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) { 1579 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len; 1580 rqstp->rq_arg.page_len = 0; 1581 } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len + 1582 rqstp->rq_arg.page_len) 1583 rqstp->rq_arg.page_len = rqstp->rq_arg.len - 1584 rqstp->rq_arg.head[0].iov_len; 1585 else 1586 rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len + 1587 rqstp->rq_arg.page_len; 1588 1589 /* Reset the response buffer */ 1590 rqstp->rq_res.head[0].iov_len = 0; 1591 1592 /* 1593 * Skip the XID and calldir fields because they've already 1594 * been processed by the caller. 1595 */ 1596 svcxdr_init_decode(rqstp); 1597 if (!xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2)) 1598 return; 1599 1600 /* Parse and execute the bc call */ 1601 proc_error = svc_process_common(rqstp); 1602 1603 atomic_dec(&req->rq_xprt->bc_slot_count); 1604 if (!proc_error) { 1605 /* Processing error: drop the request */ 1606 xprt_free_bc_request(req); 1607 return; 1608 } 1609 /* Finally, send the reply synchronously */ 1610 if (rqstp->bc_to_initval > 0) { 1611 timeout.to_initval = rqstp->bc_to_initval; 1612 timeout.to_retries = rqstp->bc_to_retries; 1613 } else { 1614 timeout.to_initval = req->rq_xprt->timeout->to_initval; 1615 timeout.to_retries = req->rq_xprt->timeout->to_retries; 1616 } 1617 timeout.to_maxval = timeout.to_initval; 1618 memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf)); 1619 task = rpc_run_bc_task(req, &timeout); 1620 1621 if (IS_ERR(task)) 1622 return; 1623 1624 WARN_ON_ONCE(atomic_read(&task->tk_count) != 1); 1625 rpc_put_task(task); 1626 } 1627 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 1628 1629 /** 1630 * svc_max_payload - Return transport-specific limit on the RPC payload 1631 * @rqstp: RPC transaction context 1632 * 1633 * Returns the maximum number of payload bytes the current transport 1634 * allows. 1635 */ 1636 u32 svc_max_payload(const struct svc_rqst *rqstp) 1637 { 1638 u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload; 1639 1640 if (rqstp->rq_server->sv_max_payload < max) 1641 max = rqstp->rq_server->sv_max_payload; 1642 return max; 1643 } 1644 EXPORT_SYMBOL_GPL(svc_max_payload); 1645 1646 /** 1647 * svc_proc_name - Return RPC procedure name in string form 1648 * @rqstp: svc_rqst to operate on 1649 * 1650 * Return value: 1651 * Pointer to a NUL-terminated string 1652 */ 1653 const char *svc_proc_name(const struct svc_rqst *rqstp) 1654 { 1655 if (rqstp && rqstp->rq_procinfo) 1656 return rqstp->rq_procinfo->pc_name; 1657 return "unknown"; 1658 } 1659 1660 1661 /** 1662 * svc_encode_result_payload - mark a range of bytes as a result payload 1663 * @rqstp: svc_rqst to operate on 1664 * @offset: payload's byte offset in rqstp->rq_res 1665 * @length: size of payload, in bytes 1666 * 1667 * Returns zero on success, or a negative errno if a permanent 1668 * error occurred. 1669 */ 1670 int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset, 1671 unsigned int length) 1672 { 1673 return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset, 1674 length); 1675 } 1676 EXPORT_SYMBOL_GPL(svc_encode_result_payload); 1677 1678 /** 1679 * svc_fill_write_vector - Construct data argument for VFS write call 1680 * @rqstp: svc_rqst to operate on 1681 * @payload: xdr_buf containing only the write data payload 1682 * 1683 * Fills in rqstp::rq_vec, and returns the number of elements. 1684 */ 1685 unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, 1686 struct xdr_buf *payload) 1687 { 1688 struct page **pages = payload->pages; 1689 struct kvec *first = payload->head; 1690 struct kvec *vec = rqstp->rq_vec; 1691 size_t total = payload->len; 1692 unsigned int i; 1693 1694 /* Some types of transport can present the write payload 1695 * entirely in rq_arg.pages. In this case, @first is empty. 1696 */ 1697 i = 0; 1698 if (first->iov_len) { 1699 vec[i].iov_base = first->iov_base; 1700 vec[i].iov_len = min_t(size_t, total, first->iov_len); 1701 total -= vec[i].iov_len; 1702 ++i; 1703 } 1704 1705 while (total) { 1706 vec[i].iov_base = page_address(*pages); 1707 vec[i].iov_len = min_t(size_t, total, PAGE_SIZE); 1708 total -= vec[i].iov_len; 1709 ++i; 1710 ++pages; 1711 } 1712 1713 WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec)); 1714 return i; 1715 } 1716 EXPORT_SYMBOL_GPL(svc_fill_write_vector); 1717 1718 /** 1719 * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call 1720 * @rqstp: svc_rqst to operate on 1721 * @first: buffer containing first section of pathname 1722 * @p: buffer containing remaining section of pathname 1723 * @total: total length of the pathname argument 1724 * 1725 * The VFS symlink API demands a NUL-terminated pathname in mapped memory. 1726 * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free 1727 * the returned string. 1728 */ 1729 char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first, 1730 void *p, size_t total) 1731 { 1732 size_t len, remaining; 1733 char *result, *dst; 1734 1735 result = kmalloc(total + 1, GFP_KERNEL); 1736 if (!result) 1737 return ERR_PTR(-ESERVERFAULT); 1738 1739 dst = result; 1740 remaining = total; 1741 1742 len = min_t(size_t, total, first->iov_len); 1743 if (len) { 1744 memcpy(dst, first->iov_base, len); 1745 dst += len; 1746 remaining -= len; 1747 } 1748 1749 if (remaining) { 1750 len = min_t(size_t, remaining, PAGE_SIZE); 1751 memcpy(dst, p, len); 1752 dst += len; 1753 } 1754 1755 *dst = '\0'; 1756 1757 /* Sanity check: Linux doesn't allow the pathname argument to 1758 * contain a NUL byte. 1759 */ 1760 if (strlen(result) != total) { 1761 kfree(result); 1762 return ERR_PTR(-EINVAL); 1763 } 1764 return result; 1765 } 1766 EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname); 1767