1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/net/sunrpc/svc_xprt.c 4 * 5 * Author: Tom Tucker <tom@opengridcomputing.com> 6 */ 7 8 #include <linux/sched.h> 9 #include <linux/sched/mm.h> 10 #include <linux/errno.h> 11 #include <linux/freezer.h> 12 #include <linux/slab.h> 13 #include <net/sock.h> 14 #include <linux/sunrpc/addr.h> 15 #include <linux/sunrpc/stats.h> 16 #include <linux/sunrpc/svc_xprt.h> 17 #include <linux/sunrpc/svcsock.h> 18 #include <linux/sunrpc/xprt.h> 19 #include <linux/sunrpc/bc_xprt.h> 20 #include <linux/module.h> 21 #include <linux/netdevice.h> 22 #include <trace/events/sunrpc.h> 23 24 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 25 26 static unsigned int svc_rpc_per_connection_limit __read_mostly; 27 module_param(svc_rpc_per_connection_limit, uint, 0644); 28 29 30 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); 31 static int svc_deferred_recv(struct svc_rqst *rqstp); 32 static struct cache_deferred_req *svc_defer(struct cache_req *req); 33 static void svc_age_temp_xprts(struct timer_list *t); 34 static void svc_delete_xprt(struct svc_xprt *xprt); 35 36 /* apparently the "standard" is that clients close 37 * idle connections after 5 minutes, servers after 38 * 6 minutes 39 * http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf 40 */ 41 static int svc_conn_age_period = 6*60; 42 43 /* List of registered transport classes */ 44 static DEFINE_SPINLOCK(svc_xprt_class_lock); 45 static LIST_HEAD(svc_xprt_class_list); 46 47 /* SMP locking strategy: 48 * 49 * svc_pool->sp_lock protects most of the fields of that pool. 50 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. 51 * when both need to be taken (rare), svc_serv->sv_lock is first. 52 * The "service mutex" protects svc_serv->sv_nrthread. 53 * svc_sock->sk_lock protects the svc_sock->sk_deferred list 54 * and the ->sk_info_authunix cache. 55 * 56 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being 57 * enqueued multiply. During normal transport processing this bit 58 * is set by svc_xprt_enqueue and cleared by svc_xprt_received. 59 * Providers should not manipulate this bit directly. 60 * 61 * Some flags can be set to certain values at any time 62 * providing that certain rules are followed: 63 * 64 * XPT_CONN, XPT_DATA: 65 * - Can be set or cleared at any time. 66 * - After a set, svc_xprt_enqueue must be called to enqueue 67 * the transport for processing. 68 * - After a clear, the transport must be read/accepted. 69 * If this succeeds, it must be set again. 70 * XPT_CLOSE: 71 * - Can set at any time. It is never cleared. 72 * XPT_DEAD: 73 * - Can only be set while XPT_BUSY is held which ensures 74 * that no other thread will be using the transport or will 75 * try to set XPT_DEAD. 76 */ 77 78 /** 79 * svc_reg_xprt_class - Register a server-side RPC transport class 80 * @xcl: New transport class to be registered 81 * 82 * Returns zero on success; otherwise a negative errno is returned. 83 */ 84 int svc_reg_xprt_class(struct svc_xprt_class *xcl) 85 { 86 struct svc_xprt_class *cl; 87 int res = -EEXIST; 88 89 INIT_LIST_HEAD(&xcl->xcl_list); 90 spin_lock(&svc_xprt_class_lock); 91 /* Make sure there isn't already a class with the same name */ 92 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { 93 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) 94 goto out; 95 } 96 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); 97 res = 0; 98 out: 99 spin_unlock(&svc_xprt_class_lock); 100 return res; 101 } 102 EXPORT_SYMBOL_GPL(svc_reg_xprt_class); 103 104 /** 105 * svc_unreg_xprt_class - Unregister a server-side RPC transport class 106 * @xcl: Transport class to be unregistered 107 * 108 */ 109 void svc_unreg_xprt_class(struct svc_xprt_class *xcl) 110 { 111 spin_lock(&svc_xprt_class_lock); 112 list_del_init(&xcl->xcl_list); 113 spin_unlock(&svc_xprt_class_lock); 114 } 115 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); 116 117 /** 118 * svc_print_xprts - Format the transport list for printing 119 * @buf: target buffer for formatted address 120 * @maxlen: length of target buffer 121 * 122 * Fills in @buf with a string containing a list of transport names, each name 123 * terminated with '\n'. If the buffer is too small, some entries may be 124 * missing, but it is guaranteed that all lines in the output buffer are 125 * complete. 126 * 127 * Returns positive length of the filled-in string. 128 */ 129 int svc_print_xprts(char *buf, int maxlen) 130 { 131 struct svc_xprt_class *xcl; 132 char tmpstr[80]; 133 int len = 0; 134 buf[0] = '\0'; 135 136 spin_lock(&svc_xprt_class_lock); 137 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 138 int slen; 139 140 slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", 141 xcl->xcl_name, xcl->xcl_max_payload); 142 if (slen >= sizeof(tmpstr) || len + slen >= maxlen) 143 break; 144 len += slen; 145 strcat(buf, tmpstr); 146 } 147 spin_unlock(&svc_xprt_class_lock); 148 149 return len; 150 } 151 152 /** 153 * svc_xprt_deferred_close - Close a transport 154 * @xprt: transport instance 155 * 156 * Used in contexts that need to defer the work of shutting down 157 * the transport to an nfsd thread. 158 */ 159 void svc_xprt_deferred_close(struct svc_xprt *xprt) 160 { 161 if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags)) 162 svc_xprt_enqueue(xprt); 163 } 164 EXPORT_SYMBOL_GPL(svc_xprt_deferred_close); 165 166 static void svc_xprt_free(struct kref *kref) 167 { 168 struct svc_xprt *xprt = 169 container_of(kref, struct svc_xprt, xpt_ref); 170 struct module *owner = xprt->xpt_class->xcl_owner; 171 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 172 svcauth_unix_info_release(xprt); 173 put_cred(xprt->xpt_cred); 174 put_net_track(xprt->xpt_net, &xprt->ns_tracker); 175 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 176 if (xprt->xpt_bc_xprt) 177 xprt_put(xprt->xpt_bc_xprt); 178 if (xprt->xpt_bc_xps) 179 xprt_switch_put(xprt->xpt_bc_xps); 180 trace_svc_xprt_free(xprt); 181 xprt->xpt_ops->xpo_free(xprt); 182 module_put(owner); 183 } 184 185 void svc_xprt_put(struct svc_xprt *xprt) 186 { 187 kref_put(&xprt->xpt_ref, svc_xprt_free); 188 } 189 EXPORT_SYMBOL_GPL(svc_xprt_put); 190 191 /* 192 * Called by transport drivers to initialize the transport independent 193 * portion of the transport instance. 194 */ 195 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 196 struct svc_xprt *xprt, struct svc_serv *serv) 197 { 198 memset(xprt, 0, sizeof(*xprt)); 199 xprt->xpt_class = xcl; 200 xprt->xpt_ops = xcl->xcl_ops; 201 kref_init(&xprt->xpt_ref); 202 xprt->xpt_server = serv; 203 INIT_LIST_HEAD(&xprt->xpt_list); 204 INIT_LIST_HEAD(&xprt->xpt_deferred); 205 INIT_LIST_HEAD(&xprt->xpt_users); 206 mutex_init(&xprt->xpt_mutex); 207 spin_lock_init(&xprt->xpt_lock); 208 set_bit(XPT_BUSY, &xprt->xpt_flags); 209 xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC); 210 strcpy(xprt->xpt_remotebuf, "uninitialized"); 211 } 212 EXPORT_SYMBOL_GPL(svc_xprt_init); 213 214 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 215 struct svc_serv *serv, 216 struct net *net, 217 const int family, 218 const unsigned short port, 219 int flags) 220 { 221 struct sockaddr_in sin = { 222 .sin_family = AF_INET, 223 .sin_addr.s_addr = htonl(INADDR_ANY), 224 .sin_port = htons(port), 225 }; 226 #if IS_ENABLED(CONFIG_IPV6) 227 struct sockaddr_in6 sin6 = { 228 .sin6_family = AF_INET6, 229 .sin6_addr = IN6ADDR_ANY_INIT, 230 .sin6_port = htons(port), 231 }; 232 #endif 233 struct svc_xprt *xprt; 234 struct sockaddr *sap; 235 size_t len; 236 237 switch (family) { 238 case PF_INET: 239 sap = (struct sockaddr *)&sin; 240 len = sizeof(sin); 241 break; 242 #if IS_ENABLED(CONFIG_IPV6) 243 case PF_INET6: 244 sap = (struct sockaddr *)&sin6; 245 len = sizeof(sin6); 246 break; 247 #endif 248 default: 249 return ERR_PTR(-EAFNOSUPPORT); 250 } 251 252 xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 253 if (IS_ERR(xprt)) 254 trace_svc_xprt_create_err(serv->sv_program->pg_name, 255 xcl->xcl_name, sap, len, xprt); 256 return xprt; 257 } 258 259 /** 260 * svc_xprt_received - start next receiver thread 261 * @xprt: controlling transport 262 * 263 * The caller must hold the XPT_BUSY bit and must 264 * not thereafter touch transport data. 265 * 266 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 267 * insufficient) data. 268 */ 269 void svc_xprt_received(struct svc_xprt *xprt) 270 { 271 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 272 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 273 return; 274 } 275 276 /* As soon as we clear busy, the xprt could be closed and 277 * 'put', so we need a reference to call svc_xprt_enqueue with: 278 */ 279 svc_xprt_get(xprt); 280 smp_mb__before_atomic(); 281 clear_bit(XPT_BUSY, &xprt->xpt_flags); 282 svc_xprt_enqueue(xprt); 283 svc_xprt_put(xprt); 284 } 285 EXPORT_SYMBOL_GPL(svc_xprt_received); 286 287 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 288 { 289 clear_bit(XPT_TEMP, &new->xpt_flags); 290 spin_lock_bh(&serv->sv_lock); 291 list_add(&new->xpt_list, &serv->sv_permsocks); 292 spin_unlock_bh(&serv->sv_lock); 293 svc_xprt_received(new); 294 } 295 296 static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 297 struct net *net, const int family, 298 const unsigned short port, int flags, 299 const struct cred *cred) 300 { 301 struct svc_xprt_class *xcl; 302 303 spin_lock(&svc_xprt_class_lock); 304 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 305 struct svc_xprt *newxprt; 306 unsigned short newport; 307 308 if (strcmp(xprt_name, xcl->xcl_name)) 309 continue; 310 311 if (!try_module_get(xcl->xcl_owner)) 312 goto err; 313 314 spin_unlock(&svc_xprt_class_lock); 315 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 316 if (IS_ERR(newxprt)) { 317 module_put(xcl->xcl_owner); 318 return PTR_ERR(newxprt); 319 } 320 newxprt->xpt_cred = get_cred(cred); 321 svc_add_new_perm_xprt(serv, newxprt); 322 newport = svc_xprt_local_port(newxprt); 323 return newport; 324 } 325 err: 326 spin_unlock(&svc_xprt_class_lock); 327 /* This errno is exposed to user space. Provide a reasonable 328 * perror msg for a bad transport. */ 329 return -EPROTONOSUPPORT; 330 } 331 332 /** 333 * svc_xprt_create - Add a new listener to @serv 334 * @serv: target RPC service 335 * @xprt_name: transport class name 336 * @net: network namespace 337 * @family: network address family 338 * @port: listener port 339 * @flags: SVC_SOCK flags 340 * @cred: credential to bind to this transport 341 * 342 * Return values: 343 * %0: New listener added successfully 344 * %-EPROTONOSUPPORT: Requested transport type not supported 345 */ 346 int svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 347 struct net *net, const int family, 348 const unsigned short port, int flags, 349 const struct cred *cred) 350 { 351 int err; 352 353 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); 354 if (err == -EPROTONOSUPPORT) { 355 request_module("svc%s", xprt_name); 356 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); 357 } 358 return err; 359 } 360 EXPORT_SYMBOL_GPL(svc_xprt_create); 361 362 /* 363 * Copy the local and remote xprt addresses to the rqstp structure 364 */ 365 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 366 { 367 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 368 rqstp->rq_addrlen = xprt->xpt_remotelen; 369 370 /* 371 * Destination address in request is needed for binding the 372 * source address in RPC replies/callbacks later. 373 */ 374 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 375 rqstp->rq_daddrlen = xprt->xpt_locallen; 376 } 377 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 378 379 /** 380 * svc_print_addr - Format rq_addr field for printing 381 * @rqstp: svc_rqst struct containing address to print 382 * @buf: target buffer for formatted address 383 * @len: length of target buffer 384 * 385 */ 386 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 387 { 388 return __svc_print_addr(svc_addr(rqstp), buf, len); 389 } 390 EXPORT_SYMBOL_GPL(svc_print_addr); 391 392 static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) 393 { 394 unsigned int limit = svc_rpc_per_connection_limit; 395 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); 396 397 return limit == 0 || (nrqsts >= 0 && nrqsts < limit); 398 } 399 400 static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) 401 { 402 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { 403 if (!svc_xprt_slots_in_range(xprt)) 404 return false; 405 atomic_inc(&xprt->xpt_nr_rqsts); 406 set_bit(RQ_DATA, &rqstp->rq_flags); 407 } 408 return true; 409 } 410 411 static void svc_xprt_release_slot(struct svc_rqst *rqstp) 412 { 413 struct svc_xprt *xprt = rqstp->rq_xprt; 414 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { 415 atomic_dec(&xprt->xpt_nr_rqsts); 416 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 417 svc_xprt_enqueue(xprt); 418 } 419 } 420 421 static bool svc_xprt_ready(struct svc_xprt *xprt) 422 { 423 unsigned long xpt_flags; 424 425 /* 426 * If another cpu has recently updated xpt_flags, 427 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to 428 * know about it; otherwise it's possible that both that cpu and 429 * this one could call svc_xprt_enqueue() without either 430 * svc_xprt_enqueue() recognizing that the conditions below 431 * are satisfied, and we could stall indefinitely: 432 */ 433 smp_rmb(); 434 xpt_flags = READ_ONCE(xprt->xpt_flags); 435 436 trace_svc_xprt_enqueue(xprt, xpt_flags); 437 if (xpt_flags & BIT(XPT_BUSY)) 438 return false; 439 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE) | BIT(XPT_HANDSHAKE))) 440 return true; 441 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { 442 if (xprt->xpt_ops->xpo_has_wspace(xprt) && 443 svc_xprt_slots_in_range(xprt)) 444 return true; 445 trace_svc_xprt_no_write_space(xprt); 446 return false; 447 } 448 return false; 449 } 450 451 /** 452 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread 453 * @xprt: transport with data pending 454 * 455 */ 456 void svc_xprt_enqueue(struct svc_xprt *xprt) 457 { 458 struct svc_pool *pool; 459 460 if (!svc_xprt_ready(xprt)) 461 return; 462 463 /* Mark transport as busy. It will remain in this state until 464 * the provider calls svc_xprt_received. We update XPT_BUSY 465 * atomically because it also guards against trying to enqueue 466 * the transport twice. 467 */ 468 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 469 return; 470 471 pool = svc_pool_for_cpu(xprt->xpt_server); 472 473 percpu_counter_inc(&pool->sp_sockets_queued); 474 lwq_enqueue(&xprt->xpt_ready, &pool->sp_xprts); 475 476 svc_pool_wake_idle_thread(pool); 477 } 478 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 479 480 /* 481 * Dequeue the first transport, if there is one. 482 */ 483 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 484 { 485 struct svc_xprt *xprt = NULL; 486 487 xprt = lwq_dequeue(&pool->sp_xprts, struct svc_xprt, xpt_ready); 488 if (xprt) 489 svc_xprt_get(xprt); 490 return xprt; 491 } 492 493 /** 494 * svc_reserve - change the space reserved for the reply to a request. 495 * @rqstp: The request in question 496 * @space: new max space to reserve 497 * 498 * Each request reserves some space on the output queue of the transport 499 * to make sure the reply fits. This function reduces that reserved 500 * space to be the amount of space used already, plus @space. 501 * 502 */ 503 void svc_reserve(struct svc_rqst *rqstp, int space) 504 { 505 struct svc_xprt *xprt = rqstp->rq_xprt; 506 507 space += rqstp->rq_res.head[0].iov_len; 508 509 if (xprt && space < rqstp->rq_reserved) { 510 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 511 rqstp->rq_reserved = space; 512 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 513 svc_xprt_enqueue(xprt); 514 } 515 } 516 EXPORT_SYMBOL_GPL(svc_reserve); 517 518 static void free_deferred(struct svc_xprt *xprt, struct svc_deferred_req *dr) 519 { 520 if (!dr) 521 return; 522 523 xprt->xpt_ops->xpo_release_ctxt(xprt, dr->xprt_ctxt); 524 kfree(dr); 525 } 526 527 static void svc_xprt_release(struct svc_rqst *rqstp) 528 { 529 struct svc_xprt *xprt = rqstp->rq_xprt; 530 531 xprt->xpt_ops->xpo_release_ctxt(xprt, rqstp->rq_xprt_ctxt); 532 rqstp->rq_xprt_ctxt = NULL; 533 534 free_deferred(xprt, rqstp->rq_deferred); 535 rqstp->rq_deferred = NULL; 536 537 svc_rqst_release_pages(rqstp); 538 rqstp->rq_res.page_len = 0; 539 rqstp->rq_res.page_base = 0; 540 541 /* Reset response buffer and release 542 * the reservation. 543 * But first, check that enough space was reserved 544 * for the reply, otherwise we have a bug! 545 */ 546 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 547 printk(KERN_ERR "RPC request reserved %d but used %d\n", 548 rqstp->rq_reserved, 549 rqstp->rq_res.len); 550 551 rqstp->rq_res.head[0].iov_len = 0; 552 svc_reserve(rqstp, 0); 553 svc_xprt_release_slot(rqstp); 554 rqstp->rq_xprt = NULL; 555 svc_xprt_put(xprt); 556 } 557 558 /** 559 * svc_wake_up - Wake up a service thread for non-transport work 560 * @serv: RPC service 561 * 562 * Some svc_serv's will have occasional work to do, even when a xprt is not 563 * waiting to be serviced. This function is there to "kick" a task in one of 564 * those services so that it can wake up and do that work. Note that we only 565 * bother with pool 0 as we don't need to wake up more than one thread for 566 * this purpose. 567 */ 568 void svc_wake_up(struct svc_serv *serv) 569 { 570 struct svc_pool *pool = &serv->sv_pools[0]; 571 572 set_bit(SP_TASK_PENDING, &pool->sp_flags); 573 svc_pool_wake_idle_thread(pool); 574 } 575 EXPORT_SYMBOL_GPL(svc_wake_up); 576 577 int svc_port_is_privileged(struct sockaddr *sin) 578 { 579 switch (sin->sa_family) { 580 case AF_INET: 581 return ntohs(((struct sockaddr_in *)sin)->sin_port) 582 < PROT_SOCK; 583 case AF_INET6: 584 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 585 < PROT_SOCK; 586 default: 587 return 0; 588 } 589 } 590 591 /* 592 * Make sure that we don't have too many active connections. If we have, 593 * something must be dropped. It's not clear what will happen if we allow 594 * "too many" connections, but when dealing with network-facing software, 595 * we have to code defensively. Here we do that by imposing hard limits. 596 * 597 * There's no point in trying to do random drop here for DoS 598 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 599 * attacker can easily beat that. 600 * 601 * The only somewhat efficient mechanism would be if drop old 602 * connections from the same IP first. But right now we don't even 603 * record the client IP in svc_sock. 604 * 605 * single-threaded services that expect a lot of clients will probably 606 * need to set sv_maxconn to override the default value which is based 607 * on the number of threads 608 */ 609 static void svc_check_conn_limits(struct svc_serv *serv) 610 { 611 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 612 (serv->sv_nrthreads+3) * 20; 613 614 if (serv->sv_tmpcnt > limit) { 615 struct svc_xprt *xprt = NULL; 616 spin_lock_bh(&serv->sv_lock); 617 if (!list_empty(&serv->sv_tempsocks)) { 618 /* Try to help the admin */ 619 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 620 serv->sv_name, serv->sv_maxconn ? 621 "max number of connections" : 622 "number of threads"); 623 /* 624 * Always select the oldest connection. It's not fair, 625 * but so is life 626 */ 627 xprt = list_entry(serv->sv_tempsocks.prev, 628 struct svc_xprt, 629 xpt_list); 630 set_bit(XPT_CLOSE, &xprt->xpt_flags); 631 svc_xprt_get(xprt); 632 } 633 spin_unlock_bh(&serv->sv_lock); 634 635 if (xprt) { 636 svc_xprt_enqueue(xprt); 637 svc_xprt_put(xprt); 638 } 639 } 640 } 641 642 static bool svc_alloc_arg(struct svc_rqst *rqstp) 643 { 644 struct svc_serv *serv = rqstp->rq_server; 645 struct xdr_buf *arg = &rqstp->rq_arg; 646 unsigned long pages, filled, ret; 647 648 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 649 if (pages > RPCSVC_MAXPAGES) { 650 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", 651 pages, RPCSVC_MAXPAGES); 652 /* use as many pages as possible */ 653 pages = RPCSVC_MAXPAGES; 654 } 655 656 for (filled = 0; filled < pages; filled = ret) { 657 ret = alloc_pages_bulk_array_node(GFP_KERNEL, 658 rqstp->rq_pool->sp_id, 659 pages, rqstp->rq_pages); 660 if (ret > filled) 661 /* Made progress, don't sleep yet */ 662 continue; 663 664 set_current_state(TASK_IDLE); 665 if (svc_thread_should_stop(rqstp)) { 666 set_current_state(TASK_RUNNING); 667 return false; 668 } 669 trace_svc_alloc_arg_err(pages, ret); 670 memalloc_retry_wait(GFP_KERNEL); 671 } 672 rqstp->rq_page_end = &rqstp->rq_pages[pages]; 673 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ 674 675 /* Make arg->head point to first page and arg->pages point to rest */ 676 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 677 arg->head[0].iov_len = PAGE_SIZE; 678 arg->pages = rqstp->rq_pages + 1; 679 arg->page_base = 0; 680 /* save at least one page for response */ 681 arg->page_len = (pages-2)*PAGE_SIZE; 682 arg->len = (pages-1)*PAGE_SIZE; 683 arg->tail[0].iov_len = 0; 684 685 rqstp->rq_xid = xdr_zero; 686 return true; 687 } 688 689 static bool 690 svc_thread_should_sleep(struct svc_rqst *rqstp) 691 { 692 struct svc_pool *pool = rqstp->rq_pool; 693 694 /* did someone call svc_wake_up? */ 695 if (test_bit(SP_TASK_PENDING, &pool->sp_flags)) 696 return false; 697 698 /* was a socket queued? */ 699 if (!lwq_empty(&pool->sp_xprts)) 700 return false; 701 702 /* are we shutting down? */ 703 if (svc_thread_should_stop(rqstp)) 704 return false; 705 706 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 707 if (svc_is_backchannel(rqstp)) { 708 if (!lwq_empty(&rqstp->rq_server->sv_cb_list)) 709 return false; 710 } 711 #endif 712 713 return true; 714 } 715 716 static void svc_thread_wait_for_work(struct svc_rqst *rqstp) 717 { 718 struct svc_pool *pool = rqstp->rq_pool; 719 720 if (svc_thread_should_sleep(rqstp)) { 721 set_current_state(TASK_IDLE | TASK_FREEZABLE); 722 llist_add(&rqstp->rq_idle, &pool->sp_idle_threads); 723 if (likely(svc_thread_should_sleep(rqstp))) 724 schedule(); 725 726 while (!llist_del_first_this(&pool->sp_idle_threads, 727 &rqstp->rq_idle)) { 728 /* Work just became available. This thread can only 729 * handle it after removing rqstp from the idle 730 * list. If that attempt failed, some other thread 731 * must have queued itself after finding no 732 * work to do, so that thread has taken responsibly 733 * for this new work. This thread can safely sleep 734 * until woken again. 735 */ 736 schedule(); 737 set_current_state(TASK_IDLE | TASK_FREEZABLE); 738 } 739 __set_current_state(TASK_RUNNING); 740 } else { 741 cond_resched(); 742 } 743 try_to_freeze(); 744 } 745 746 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 747 { 748 spin_lock_bh(&serv->sv_lock); 749 set_bit(XPT_TEMP, &newxpt->xpt_flags); 750 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 751 serv->sv_tmpcnt++; 752 if (serv->sv_temptimer.function == NULL) { 753 /* setup timer to age temp transports */ 754 serv->sv_temptimer.function = svc_age_temp_xprts; 755 mod_timer(&serv->sv_temptimer, 756 jiffies + svc_conn_age_period * HZ); 757 } 758 spin_unlock_bh(&serv->sv_lock); 759 svc_xprt_received(newxpt); 760 } 761 762 static void svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 763 { 764 struct svc_serv *serv = rqstp->rq_server; 765 int len = 0; 766 767 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 768 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 769 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 770 svc_delete_xprt(xprt); 771 /* Leave XPT_BUSY set on the dead xprt: */ 772 goto out; 773 } 774 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 775 struct svc_xprt *newxpt; 776 /* 777 * We know this module_get will succeed because the 778 * listener holds a reference too 779 */ 780 __module_get(xprt->xpt_class->xcl_owner); 781 svc_check_conn_limits(xprt->xpt_server); 782 newxpt = xprt->xpt_ops->xpo_accept(xprt); 783 if (newxpt) { 784 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 785 svc_add_new_temp_xprt(serv, newxpt); 786 trace_svc_xprt_accept(newxpt, serv->sv_name); 787 } else { 788 module_put(xprt->xpt_class->xcl_owner); 789 } 790 svc_xprt_received(xprt); 791 } else if (test_bit(XPT_HANDSHAKE, &xprt->xpt_flags)) { 792 xprt->xpt_ops->xpo_handshake(xprt); 793 svc_xprt_received(xprt); 794 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 795 /* XPT_DATA|XPT_DEFERRED case: */ 796 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 797 if (rqstp->rq_deferred) 798 len = svc_deferred_recv(rqstp); 799 else 800 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 801 rqstp->rq_reserved = serv->sv_max_mesg; 802 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 803 if (len <= 0) 804 goto out; 805 806 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 807 808 clear_bit(XPT_OLD, &xprt->xpt_flags); 809 810 rqstp->rq_chandle.defer = svc_defer; 811 812 if (serv->sv_stats) 813 serv->sv_stats->netcnt++; 814 percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived); 815 rqstp->rq_stime = ktime_get(); 816 svc_process(rqstp); 817 } else 818 svc_xprt_received(xprt); 819 820 out: 821 rqstp->rq_res.len = 0; 822 svc_xprt_release(rqstp); 823 } 824 825 static void svc_thread_wake_next(struct svc_rqst *rqstp) 826 { 827 if (!svc_thread_should_sleep(rqstp)) 828 /* More work pending after I dequeued some, 829 * wake another worker 830 */ 831 svc_pool_wake_idle_thread(rqstp->rq_pool); 832 } 833 834 /** 835 * svc_recv - Receive and process the next request on any transport 836 * @rqstp: an idle RPC service thread 837 * 838 * This code is carefully organised not to touch any cachelines in 839 * the shared svc_serv structure, only cachelines in the local 840 * svc_pool. 841 */ 842 void svc_recv(struct svc_rqst *rqstp) 843 { 844 struct svc_pool *pool = rqstp->rq_pool; 845 846 if (!svc_alloc_arg(rqstp)) 847 return; 848 849 svc_thread_wait_for_work(rqstp); 850 851 clear_bit(SP_TASK_PENDING, &pool->sp_flags); 852 853 if (svc_thread_should_stop(rqstp)) { 854 svc_thread_wake_next(rqstp); 855 return; 856 } 857 858 rqstp->rq_xprt = svc_xprt_dequeue(pool); 859 if (rqstp->rq_xprt) { 860 struct svc_xprt *xprt = rqstp->rq_xprt; 861 862 svc_thread_wake_next(rqstp); 863 /* Normally we will wait up to 5 seconds for any required 864 * cache information to be provided. When there are no 865 * idle threads, we reduce the wait time. 866 */ 867 if (pool->sp_idle_threads.first) 868 rqstp->rq_chandle.thread_wait = 5 * HZ; 869 else 870 rqstp->rq_chandle.thread_wait = 1 * HZ; 871 872 trace_svc_xprt_dequeue(rqstp); 873 svc_handle_xprt(rqstp, xprt); 874 } 875 876 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 877 if (svc_is_backchannel(rqstp)) { 878 struct svc_serv *serv = rqstp->rq_server; 879 struct rpc_rqst *req; 880 881 req = lwq_dequeue(&serv->sv_cb_list, 882 struct rpc_rqst, rq_bc_list); 883 if (req) { 884 svc_thread_wake_next(rqstp); 885 svc_process_bc(req, rqstp); 886 } 887 } 888 #endif 889 } 890 EXPORT_SYMBOL_GPL(svc_recv); 891 892 /* 893 * Drop request 894 */ 895 void svc_drop(struct svc_rqst *rqstp) 896 { 897 trace_svc_drop(rqstp); 898 } 899 EXPORT_SYMBOL_GPL(svc_drop); 900 901 /** 902 * svc_send - Return reply to client 903 * @rqstp: RPC transaction context 904 * 905 */ 906 void svc_send(struct svc_rqst *rqstp) 907 { 908 struct svc_xprt *xprt; 909 struct xdr_buf *xb; 910 int status; 911 912 xprt = rqstp->rq_xprt; 913 914 /* calculate over-all length */ 915 xb = &rqstp->rq_res; 916 xb->len = xb->head[0].iov_len + 917 xb->page_len + 918 xb->tail[0].iov_len; 919 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 920 trace_svc_stats_latency(rqstp); 921 922 status = xprt->xpt_ops->xpo_sendto(rqstp); 923 924 trace_svc_send(rqstp, status); 925 } 926 927 /* 928 * Timer function to close old temporary transports, using 929 * a mark-and-sweep algorithm. 930 */ 931 static void svc_age_temp_xprts(struct timer_list *t) 932 { 933 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 934 struct svc_xprt *xprt; 935 struct list_head *le, *next; 936 937 dprintk("svc_age_temp_xprts\n"); 938 939 if (!spin_trylock_bh(&serv->sv_lock)) { 940 /* busy, try again 1 sec later */ 941 dprintk("svc_age_temp_xprts: busy\n"); 942 mod_timer(&serv->sv_temptimer, jiffies + HZ); 943 return; 944 } 945 946 list_for_each_safe(le, next, &serv->sv_tempsocks) { 947 xprt = list_entry(le, struct svc_xprt, xpt_list); 948 949 /* First time through, just mark it OLD. Second time 950 * through, close it. */ 951 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 952 continue; 953 if (kref_read(&xprt->xpt_ref) > 1 || 954 test_bit(XPT_BUSY, &xprt->xpt_flags)) 955 continue; 956 list_del_init(le); 957 set_bit(XPT_CLOSE, &xprt->xpt_flags); 958 dprintk("queuing xprt %p for closing\n", xprt); 959 960 /* a thread will dequeue and close it soon */ 961 svc_xprt_enqueue(xprt); 962 } 963 spin_unlock_bh(&serv->sv_lock); 964 965 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 966 } 967 968 /* Close temporary transports whose xpt_local matches server_addr immediately 969 * instead of waiting for them to be picked up by the timer. 970 * 971 * This is meant to be called from a notifier_block that runs when an ip 972 * address is deleted. 973 */ 974 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 975 { 976 struct svc_xprt *xprt; 977 struct list_head *le, *next; 978 LIST_HEAD(to_be_closed); 979 980 spin_lock_bh(&serv->sv_lock); 981 list_for_each_safe(le, next, &serv->sv_tempsocks) { 982 xprt = list_entry(le, struct svc_xprt, xpt_list); 983 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 984 &xprt->xpt_local)) { 985 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 986 list_move(le, &to_be_closed); 987 } 988 } 989 spin_unlock_bh(&serv->sv_lock); 990 991 while (!list_empty(&to_be_closed)) { 992 le = to_be_closed.next; 993 list_del_init(le); 994 xprt = list_entry(le, struct svc_xprt, xpt_list); 995 set_bit(XPT_CLOSE, &xprt->xpt_flags); 996 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 997 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 998 xprt); 999 svc_xprt_enqueue(xprt); 1000 } 1001 } 1002 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1003 1004 static void call_xpt_users(struct svc_xprt *xprt) 1005 { 1006 struct svc_xpt_user *u; 1007 1008 spin_lock(&xprt->xpt_lock); 1009 while (!list_empty(&xprt->xpt_users)) { 1010 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1011 list_del_init(&u->list); 1012 u->callback(u); 1013 } 1014 spin_unlock(&xprt->xpt_lock); 1015 } 1016 1017 /* 1018 * Remove a dead transport 1019 */ 1020 static void svc_delete_xprt(struct svc_xprt *xprt) 1021 { 1022 struct svc_serv *serv = xprt->xpt_server; 1023 struct svc_deferred_req *dr; 1024 1025 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1026 return; 1027 1028 trace_svc_xprt_detach(xprt); 1029 xprt->xpt_ops->xpo_detach(xprt); 1030 if (xprt->xpt_bc_xprt) 1031 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1032 1033 spin_lock_bh(&serv->sv_lock); 1034 list_del_init(&xprt->xpt_list); 1035 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1036 serv->sv_tmpcnt--; 1037 spin_unlock_bh(&serv->sv_lock); 1038 1039 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1040 free_deferred(xprt, dr); 1041 1042 call_xpt_users(xprt); 1043 svc_xprt_put(xprt); 1044 } 1045 1046 /** 1047 * svc_xprt_close - Close a client connection 1048 * @xprt: transport to disconnect 1049 * 1050 */ 1051 void svc_xprt_close(struct svc_xprt *xprt) 1052 { 1053 trace_svc_xprt_close(xprt); 1054 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1055 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1056 /* someone else will have to effect the close */ 1057 return; 1058 /* 1059 * We expect svc_close_xprt() to work even when no threads are 1060 * running (e.g., while configuring the server before starting 1061 * any threads), so if the transport isn't busy, we delete 1062 * it ourself: 1063 */ 1064 svc_delete_xprt(xprt); 1065 } 1066 EXPORT_SYMBOL_GPL(svc_xprt_close); 1067 1068 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1069 { 1070 struct svc_xprt *xprt; 1071 int ret = 0; 1072 1073 spin_lock_bh(&serv->sv_lock); 1074 list_for_each_entry(xprt, xprt_list, xpt_list) { 1075 if (xprt->xpt_net != net) 1076 continue; 1077 ret++; 1078 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1079 svc_xprt_enqueue(xprt); 1080 } 1081 spin_unlock_bh(&serv->sv_lock); 1082 return ret; 1083 } 1084 1085 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1086 { 1087 struct svc_xprt *xprt; 1088 int i; 1089 1090 for (i = 0; i < serv->sv_nrpools; i++) { 1091 struct svc_pool *pool = &serv->sv_pools[i]; 1092 struct llist_node *q, **t1, *t2; 1093 1094 q = lwq_dequeue_all(&pool->sp_xprts); 1095 lwq_for_each_safe(xprt, t1, t2, &q, xpt_ready) { 1096 if (xprt->xpt_net == net) { 1097 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1098 svc_delete_xprt(xprt); 1099 xprt = NULL; 1100 } 1101 } 1102 1103 if (q) 1104 lwq_enqueue_batch(q, &pool->sp_xprts); 1105 } 1106 } 1107 1108 /** 1109 * svc_xprt_destroy_all - Destroy transports associated with @serv 1110 * @serv: RPC service to be shut down 1111 * @net: target network namespace 1112 * 1113 * Server threads may still be running (especially in the case where the 1114 * service is still running in other network namespaces). 1115 * 1116 * So we shut down sockets the same way we would on a running server, by 1117 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1118 * the close. In the case there are no such other threads, 1119 * threads running, svc_clean_up_xprts() does a simple version of a 1120 * server's main event loop, and in the case where there are other 1121 * threads, we may need to wait a little while and then check again to 1122 * see if they're done. 1123 */ 1124 void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) 1125 { 1126 int delay = 0; 1127 1128 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1129 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1130 1131 svc_clean_up_xprts(serv, net); 1132 msleep(delay++); 1133 } 1134 } 1135 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); 1136 1137 /* 1138 * Handle defer and revisit of requests 1139 */ 1140 1141 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1142 { 1143 struct svc_deferred_req *dr = 1144 container_of(dreq, struct svc_deferred_req, handle); 1145 struct svc_xprt *xprt = dr->xprt; 1146 1147 spin_lock(&xprt->xpt_lock); 1148 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1149 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1150 spin_unlock(&xprt->xpt_lock); 1151 trace_svc_defer_drop(dr); 1152 free_deferred(xprt, dr); 1153 svc_xprt_put(xprt); 1154 return; 1155 } 1156 dr->xprt = NULL; 1157 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1158 spin_unlock(&xprt->xpt_lock); 1159 trace_svc_defer_queue(dr); 1160 svc_xprt_enqueue(xprt); 1161 svc_xprt_put(xprt); 1162 } 1163 1164 /* 1165 * Save the request off for later processing. The request buffer looks 1166 * like this: 1167 * 1168 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1169 * 1170 * This code can only handle requests that consist of an xprt-header 1171 * and rpc-header. 1172 */ 1173 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1174 { 1175 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1176 struct svc_deferred_req *dr; 1177 1178 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1179 return NULL; /* if more than a page, give up FIXME */ 1180 if (rqstp->rq_deferred) { 1181 dr = rqstp->rq_deferred; 1182 rqstp->rq_deferred = NULL; 1183 } else { 1184 size_t skip; 1185 size_t size; 1186 /* FIXME maybe discard if size too large */ 1187 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1188 dr = kmalloc(size, GFP_KERNEL); 1189 if (dr == NULL) 1190 return NULL; 1191 1192 dr->handle.owner = rqstp->rq_server; 1193 dr->prot = rqstp->rq_prot; 1194 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1195 dr->addrlen = rqstp->rq_addrlen; 1196 dr->daddr = rqstp->rq_daddr; 1197 dr->argslen = rqstp->rq_arg.len >> 2; 1198 1199 /* back up head to the start of the buffer and copy */ 1200 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1201 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1202 dr->argslen << 2); 1203 } 1204 dr->xprt_ctxt = rqstp->rq_xprt_ctxt; 1205 rqstp->rq_xprt_ctxt = NULL; 1206 trace_svc_defer(rqstp); 1207 svc_xprt_get(rqstp->rq_xprt); 1208 dr->xprt = rqstp->rq_xprt; 1209 set_bit(RQ_DROPME, &rqstp->rq_flags); 1210 1211 dr->handle.revisit = svc_revisit; 1212 return &dr->handle; 1213 } 1214 1215 /* 1216 * recv data from a deferred request into an active one 1217 */ 1218 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1219 { 1220 struct svc_deferred_req *dr = rqstp->rq_deferred; 1221 1222 trace_svc_defer_recv(dr); 1223 1224 /* setup iov_base past transport header */ 1225 rqstp->rq_arg.head[0].iov_base = dr->args; 1226 /* The iov_len does not include the transport header bytes */ 1227 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; 1228 rqstp->rq_arg.page_len = 0; 1229 /* The rq_arg.len includes the transport header bytes */ 1230 rqstp->rq_arg.len = dr->argslen << 2; 1231 rqstp->rq_prot = dr->prot; 1232 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1233 rqstp->rq_addrlen = dr->addrlen; 1234 /* Save off transport header len in case we get deferred again */ 1235 rqstp->rq_daddr = dr->daddr; 1236 rqstp->rq_respages = rqstp->rq_pages; 1237 rqstp->rq_xprt_ctxt = dr->xprt_ctxt; 1238 1239 dr->xprt_ctxt = NULL; 1240 svc_xprt_received(rqstp->rq_xprt); 1241 return dr->argslen << 2; 1242 } 1243 1244 1245 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1246 { 1247 struct svc_deferred_req *dr = NULL; 1248 1249 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1250 return NULL; 1251 spin_lock(&xprt->xpt_lock); 1252 if (!list_empty(&xprt->xpt_deferred)) { 1253 dr = list_entry(xprt->xpt_deferred.next, 1254 struct svc_deferred_req, 1255 handle.recent); 1256 list_del_init(&dr->handle.recent); 1257 } else 1258 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1259 spin_unlock(&xprt->xpt_lock); 1260 return dr; 1261 } 1262 1263 /** 1264 * svc_find_xprt - find an RPC transport instance 1265 * @serv: pointer to svc_serv to search 1266 * @xcl_name: C string containing transport's class name 1267 * @net: owner net pointer 1268 * @af: Address family of transport's local address 1269 * @port: transport's IP port number 1270 * 1271 * Return the transport instance pointer for the endpoint accepting 1272 * connections/peer traffic from the specified transport class, 1273 * address family and port. 1274 * 1275 * Specifying 0 for the address family or port is effectively a 1276 * wild-card, and will result in matching the first transport in the 1277 * service's list that has a matching class name. 1278 */ 1279 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1280 struct net *net, const sa_family_t af, 1281 const unsigned short port) 1282 { 1283 struct svc_xprt *xprt; 1284 struct svc_xprt *found = NULL; 1285 1286 /* Sanity check the args */ 1287 if (serv == NULL || xcl_name == NULL) 1288 return found; 1289 1290 spin_lock_bh(&serv->sv_lock); 1291 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1292 if (xprt->xpt_net != net) 1293 continue; 1294 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1295 continue; 1296 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1297 continue; 1298 if (port != 0 && port != svc_xprt_local_port(xprt)) 1299 continue; 1300 found = xprt; 1301 svc_xprt_get(xprt); 1302 break; 1303 } 1304 spin_unlock_bh(&serv->sv_lock); 1305 return found; 1306 } 1307 EXPORT_SYMBOL_GPL(svc_find_xprt); 1308 1309 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1310 char *pos, int remaining) 1311 { 1312 int len; 1313 1314 len = snprintf(pos, remaining, "%s %u\n", 1315 xprt->xpt_class->xcl_name, 1316 svc_xprt_local_port(xprt)); 1317 if (len >= remaining) 1318 return -ENAMETOOLONG; 1319 return len; 1320 } 1321 1322 /** 1323 * svc_xprt_names - format a buffer with a list of transport names 1324 * @serv: pointer to an RPC service 1325 * @buf: pointer to a buffer to be filled in 1326 * @buflen: length of buffer to be filled in 1327 * 1328 * Fills in @buf with a string containing a list of transport names, 1329 * each name terminated with '\n'. 1330 * 1331 * Returns positive length of the filled-in string on success; otherwise 1332 * a negative errno value is returned if an error occurs. 1333 */ 1334 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1335 { 1336 struct svc_xprt *xprt; 1337 int len, totlen; 1338 char *pos; 1339 1340 /* Sanity check args */ 1341 if (!serv) 1342 return 0; 1343 1344 spin_lock_bh(&serv->sv_lock); 1345 1346 pos = buf; 1347 totlen = 0; 1348 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1349 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1350 if (len < 0) { 1351 *buf = '\0'; 1352 totlen = len; 1353 } 1354 if (len <= 0) 1355 break; 1356 1357 pos += len; 1358 totlen += len; 1359 } 1360 1361 spin_unlock_bh(&serv->sv_lock); 1362 return totlen; 1363 } 1364 EXPORT_SYMBOL_GPL(svc_xprt_names); 1365 1366 1367 /*----------------------------------------------------------------------------*/ 1368 1369 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1370 { 1371 unsigned int pidx = (unsigned int)*pos; 1372 struct svc_serv *serv = m->private; 1373 1374 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1375 1376 if (!pidx) 1377 return SEQ_START_TOKEN; 1378 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1379 } 1380 1381 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1382 { 1383 struct svc_pool *pool = p; 1384 struct svc_serv *serv = m->private; 1385 1386 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1387 1388 if (p == SEQ_START_TOKEN) { 1389 pool = &serv->sv_pools[0]; 1390 } else { 1391 unsigned int pidx = (pool - &serv->sv_pools[0]); 1392 if (pidx < serv->sv_nrpools-1) 1393 pool = &serv->sv_pools[pidx+1]; 1394 else 1395 pool = NULL; 1396 } 1397 ++*pos; 1398 return pool; 1399 } 1400 1401 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1402 { 1403 } 1404 1405 static int svc_pool_stats_show(struct seq_file *m, void *p) 1406 { 1407 struct svc_pool *pool = p; 1408 1409 if (p == SEQ_START_TOKEN) { 1410 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1411 return 0; 1412 } 1413 1414 seq_printf(m, "%u %llu %llu %llu 0\n", 1415 pool->sp_id, 1416 percpu_counter_sum_positive(&pool->sp_messages_arrived), 1417 percpu_counter_sum_positive(&pool->sp_sockets_queued), 1418 percpu_counter_sum_positive(&pool->sp_threads_woken)); 1419 1420 return 0; 1421 } 1422 1423 static const struct seq_operations svc_pool_stats_seq_ops = { 1424 .start = svc_pool_stats_start, 1425 .next = svc_pool_stats_next, 1426 .stop = svc_pool_stats_stop, 1427 .show = svc_pool_stats_show, 1428 }; 1429 1430 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1431 { 1432 int err; 1433 1434 err = seq_open(file, &svc_pool_stats_seq_ops); 1435 if (!err) 1436 ((struct seq_file *) file->private_data)->private = serv; 1437 return err; 1438 } 1439 EXPORT_SYMBOL(svc_pool_stats_open); 1440 1441 /*----------------------------------------------------------------------------*/ 1442