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(GFP_KERNEL, pages, 658 rqstp->rq_pages); 659 if (ret > filled) 660 /* Made progress, don't sleep yet */ 661 continue; 662 663 set_current_state(TASK_IDLE); 664 if (svc_thread_should_stop(rqstp)) { 665 set_current_state(TASK_RUNNING); 666 return false; 667 } 668 trace_svc_alloc_arg_err(pages, ret); 669 memalloc_retry_wait(GFP_KERNEL); 670 } 671 rqstp->rq_page_end = &rqstp->rq_pages[pages]; 672 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ 673 674 /* Make arg->head point to first page and arg->pages point to rest */ 675 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 676 arg->head[0].iov_len = PAGE_SIZE; 677 arg->pages = rqstp->rq_pages + 1; 678 arg->page_base = 0; 679 /* save at least one page for response */ 680 arg->page_len = (pages-2)*PAGE_SIZE; 681 arg->len = (pages-1)*PAGE_SIZE; 682 arg->tail[0].iov_len = 0; 683 684 rqstp->rq_xid = xdr_zero; 685 return true; 686 } 687 688 static bool 689 svc_thread_should_sleep(struct svc_rqst *rqstp) 690 { 691 struct svc_pool *pool = rqstp->rq_pool; 692 693 /* did someone call svc_wake_up? */ 694 if (test_bit(SP_TASK_PENDING, &pool->sp_flags)) 695 return false; 696 697 /* was a socket queued? */ 698 if (!lwq_empty(&pool->sp_xprts)) 699 return false; 700 701 /* are we shutting down? */ 702 if (svc_thread_should_stop(rqstp)) 703 return false; 704 705 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 706 if (svc_is_backchannel(rqstp)) { 707 if (!lwq_empty(&rqstp->rq_server->sv_cb_list)) 708 return false; 709 } 710 #endif 711 712 return true; 713 } 714 715 static void svc_thread_wait_for_work(struct svc_rqst *rqstp) 716 { 717 struct svc_pool *pool = rqstp->rq_pool; 718 719 if (svc_thread_should_sleep(rqstp)) { 720 set_current_state(TASK_IDLE | TASK_FREEZABLE); 721 llist_add(&rqstp->rq_idle, &pool->sp_idle_threads); 722 if (likely(svc_thread_should_sleep(rqstp))) 723 schedule(); 724 725 while (!llist_del_first_this(&pool->sp_idle_threads, 726 &rqstp->rq_idle)) { 727 /* Work just became available. This thread can only 728 * handle it after removing rqstp from the idle 729 * list. If that attempt failed, some other thread 730 * must have queued itself after finding no 731 * work to do, so that thread has taken responsibly 732 * for this new work. This thread can safely sleep 733 * until woken again. 734 */ 735 schedule(); 736 set_current_state(TASK_IDLE | TASK_FREEZABLE); 737 } 738 __set_current_state(TASK_RUNNING); 739 } else { 740 cond_resched(); 741 } 742 try_to_freeze(); 743 } 744 745 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 746 { 747 spin_lock_bh(&serv->sv_lock); 748 set_bit(XPT_TEMP, &newxpt->xpt_flags); 749 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 750 serv->sv_tmpcnt++; 751 if (serv->sv_temptimer.function == NULL) { 752 /* setup timer to age temp transports */ 753 serv->sv_temptimer.function = svc_age_temp_xprts; 754 mod_timer(&serv->sv_temptimer, 755 jiffies + svc_conn_age_period * HZ); 756 } 757 spin_unlock_bh(&serv->sv_lock); 758 svc_xprt_received(newxpt); 759 } 760 761 static void svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 762 { 763 struct svc_serv *serv = rqstp->rq_server; 764 int len = 0; 765 766 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 767 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 768 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 769 svc_delete_xprt(xprt); 770 /* Leave XPT_BUSY set on the dead xprt: */ 771 goto out; 772 } 773 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 774 struct svc_xprt *newxpt; 775 /* 776 * We know this module_get will succeed because the 777 * listener holds a reference too 778 */ 779 __module_get(xprt->xpt_class->xcl_owner); 780 svc_check_conn_limits(xprt->xpt_server); 781 newxpt = xprt->xpt_ops->xpo_accept(xprt); 782 if (newxpt) { 783 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 784 svc_add_new_temp_xprt(serv, newxpt); 785 trace_svc_xprt_accept(newxpt, serv->sv_name); 786 } else { 787 module_put(xprt->xpt_class->xcl_owner); 788 } 789 svc_xprt_received(xprt); 790 } else if (test_bit(XPT_HANDSHAKE, &xprt->xpt_flags)) { 791 xprt->xpt_ops->xpo_handshake(xprt); 792 svc_xprt_received(xprt); 793 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 794 /* XPT_DATA|XPT_DEFERRED case: */ 795 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 796 if (rqstp->rq_deferred) 797 len = svc_deferred_recv(rqstp); 798 else 799 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 800 rqstp->rq_reserved = serv->sv_max_mesg; 801 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 802 if (len <= 0) 803 goto out; 804 805 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 806 807 clear_bit(XPT_OLD, &xprt->xpt_flags); 808 809 rqstp->rq_chandle.defer = svc_defer; 810 811 if (serv->sv_stats) 812 serv->sv_stats->netcnt++; 813 percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived); 814 rqstp->rq_stime = ktime_get(); 815 svc_process(rqstp); 816 } else 817 svc_xprt_received(xprt); 818 819 out: 820 rqstp->rq_res.len = 0; 821 svc_xprt_release(rqstp); 822 } 823 824 static void svc_thread_wake_next(struct svc_rqst *rqstp) 825 { 826 if (!svc_thread_should_sleep(rqstp)) 827 /* More work pending after I dequeued some, 828 * wake another worker 829 */ 830 svc_pool_wake_idle_thread(rqstp->rq_pool); 831 } 832 833 /** 834 * svc_recv - Receive and process the next request on any transport 835 * @rqstp: an idle RPC service thread 836 * 837 * This code is carefully organised not to touch any cachelines in 838 * the shared svc_serv structure, only cachelines in the local 839 * svc_pool. 840 */ 841 void svc_recv(struct svc_rqst *rqstp) 842 { 843 struct svc_pool *pool = rqstp->rq_pool; 844 845 if (!svc_alloc_arg(rqstp)) 846 return; 847 848 svc_thread_wait_for_work(rqstp); 849 850 clear_bit(SP_TASK_PENDING, &pool->sp_flags); 851 852 if (svc_thread_should_stop(rqstp)) { 853 svc_thread_wake_next(rqstp); 854 return; 855 } 856 857 rqstp->rq_xprt = svc_xprt_dequeue(pool); 858 if (rqstp->rq_xprt) { 859 struct svc_xprt *xprt = rqstp->rq_xprt; 860 861 svc_thread_wake_next(rqstp); 862 /* Normally we will wait up to 5 seconds for any required 863 * cache information to be provided. When there are no 864 * idle threads, we reduce the wait time. 865 */ 866 if (pool->sp_idle_threads.first) 867 rqstp->rq_chandle.thread_wait = 5 * HZ; 868 else 869 rqstp->rq_chandle.thread_wait = 1 * HZ; 870 871 trace_svc_xprt_dequeue(rqstp); 872 svc_handle_xprt(rqstp, xprt); 873 } 874 875 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 876 if (svc_is_backchannel(rqstp)) { 877 struct svc_serv *serv = rqstp->rq_server; 878 struct rpc_rqst *req; 879 880 req = lwq_dequeue(&serv->sv_cb_list, 881 struct rpc_rqst, rq_bc_list); 882 if (req) { 883 svc_thread_wake_next(rqstp); 884 svc_process_bc(req, rqstp); 885 } 886 } 887 #endif 888 } 889 EXPORT_SYMBOL_GPL(svc_recv); 890 891 /* 892 * Drop request 893 */ 894 void svc_drop(struct svc_rqst *rqstp) 895 { 896 trace_svc_drop(rqstp); 897 } 898 EXPORT_SYMBOL_GPL(svc_drop); 899 900 /** 901 * svc_send - Return reply to client 902 * @rqstp: RPC transaction context 903 * 904 */ 905 void svc_send(struct svc_rqst *rqstp) 906 { 907 struct svc_xprt *xprt; 908 struct xdr_buf *xb; 909 int status; 910 911 xprt = rqstp->rq_xprt; 912 913 /* calculate over-all length */ 914 xb = &rqstp->rq_res; 915 xb->len = xb->head[0].iov_len + 916 xb->page_len + 917 xb->tail[0].iov_len; 918 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 919 trace_svc_stats_latency(rqstp); 920 921 status = xprt->xpt_ops->xpo_sendto(rqstp); 922 923 trace_svc_send(rqstp, status); 924 } 925 926 /* 927 * Timer function to close old temporary transports, using 928 * a mark-and-sweep algorithm. 929 */ 930 static void svc_age_temp_xprts(struct timer_list *t) 931 { 932 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 933 struct svc_xprt *xprt; 934 struct list_head *le, *next; 935 936 dprintk("svc_age_temp_xprts\n"); 937 938 if (!spin_trylock_bh(&serv->sv_lock)) { 939 /* busy, try again 1 sec later */ 940 dprintk("svc_age_temp_xprts: busy\n"); 941 mod_timer(&serv->sv_temptimer, jiffies + HZ); 942 return; 943 } 944 945 list_for_each_safe(le, next, &serv->sv_tempsocks) { 946 xprt = list_entry(le, struct svc_xprt, xpt_list); 947 948 /* First time through, just mark it OLD. Second time 949 * through, close it. */ 950 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 951 continue; 952 if (kref_read(&xprt->xpt_ref) > 1 || 953 test_bit(XPT_BUSY, &xprt->xpt_flags)) 954 continue; 955 list_del_init(le); 956 set_bit(XPT_CLOSE, &xprt->xpt_flags); 957 dprintk("queuing xprt %p for closing\n", xprt); 958 959 /* a thread will dequeue and close it soon */ 960 svc_xprt_enqueue(xprt); 961 } 962 spin_unlock_bh(&serv->sv_lock); 963 964 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 965 } 966 967 /* Close temporary transports whose xpt_local matches server_addr immediately 968 * instead of waiting for them to be picked up by the timer. 969 * 970 * This is meant to be called from a notifier_block that runs when an ip 971 * address is deleted. 972 */ 973 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 974 { 975 struct svc_xprt *xprt; 976 struct list_head *le, *next; 977 LIST_HEAD(to_be_closed); 978 979 spin_lock_bh(&serv->sv_lock); 980 list_for_each_safe(le, next, &serv->sv_tempsocks) { 981 xprt = list_entry(le, struct svc_xprt, xpt_list); 982 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 983 &xprt->xpt_local)) { 984 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 985 list_move(le, &to_be_closed); 986 } 987 } 988 spin_unlock_bh(&serv->sv_lock); 989 990 while (!list_empty(&to_be_closed)) { 991 le = to_be_closed.next; 992 list_del_init(le); 993 xprt = list_entry(le, struct svc_xprt, xpt_list); 994 set_bit(XPT_CLOSE, &xprt->xpt_flags); 995 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 996 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 997 xprt); 998 svc_xprt_enqueue(xprt); 999 } 1000 } 1001 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1002 1003 static void call_xpt_users(struct svc_xprt *xprt) 1004 { 1005 struct svc_xpt_user *u; 1006 1007 spin_lock(&xprt->xpt_lock); 1008 while (!list_empty(&xprt->xpt_users)) { 1009 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1010 list_del_init(&u->list); 1011 u->callback(u); 1012 } 1013 spin_unlock(&xprt->xpt_lock); 1014 } 1015 1016 /* 1017 * Remove a dead transport 1018 */ 1019 static void svc_delete_xprt(struct svc_xprt *xprt) 1020 { 1021 struct svc_serv *serv = xprt->xpt_server; 1022 struct svc_deferred_req *dr; 1023 1024 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1025 return; 1026 1027 trace_svc_xprt_detach(xprt); 1028 xprt->xpt_ops->xpo_detach(xprt); 1029 if (xprt->xpt_bc_xprt) 1030 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1031 1032 spin_lock_bh(&serv->sv_lock); 1033 list_del_init(&xprt->xpt_list); 1034 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1035 serv->sv_tmpcnt--; 1036 spin_unlock_bh(&serv->sv_lock); 1037 1038 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1039 free_deferred(xprt, dr); 1040 1041 call_xpt_users(xprt); 1042 svc_xprt_put(xprt); 1043 } 1044 1045 /** 1046 * svc_xprt_close - Close a client connection 1047 * @xprt: transport to disconnect 1048 * 1049 */ 1050 void svc_xprt_close(struct svc_xprt *xprt) 1051 { 1052 trace_svc_xprt_close(xprt); 1053 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1054 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1055 /* someone else will have to effect the close */ 1056 return; 1057 /* 1058 * We expect svc_close_xprt() to work even when no threads are 1059 * running (e.g., while configuring the server before starting 1060 * any threads), so if the transport isn't busy, we delete 1061 * it ourself: 1062 */ 1063 svc_delete_xprt(xprt); 1064 } 1065 EXPORT_SYMBOL_GPL(svc_xprt_close); 1066 1067 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1068 { 1069 struct svc_xprt *xprt; 1070 int ret = 0; 1071 1072 spin_lock_bh(&serv->sv_lock); 1073 list_for_each_entry(xprt, xprt_list, xpt_list) { 1074 if (xprt->xpt_net != net) 1075 continue; 1076 ret++; 1077 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1078 svc_xprt_enqueue(xprt); 1079 } 1080 spin_unlock_bh(&serv->sv_lock); 1081 return ret; 1082 } 1083 1084 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1085 { 1086 struct svc_xprt *xprt; 1087 int i; 1088 1089 for (i = 0; i < serv->sv_nrpools; i++) { 1090 struct svc_pool *pool = &serv->sv_pools[i]; 1091 struct llist_node *q, **t1, *t2; 1092 1093 q = lwq_dequeue_all(&pool->sp_xprts); 1094 lwq_for_each_safe(xprt, t1, t2, &q, xpt_ready) { 1095 if (xprt->xpt_net == net) { 1096 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1097 svc_delete_xprt(xprt); 1098 xprt = NULL; 1099 } 1100 } 1101 1102 if (q) 1103 lwq_enqueue_batch(q, &pool->sp_xprts); 1104 } 1105 } 1106 1107 /** 1108 * svc_xprt_destroy_all - Destroy transports associated with @serv 1109 * @serv: RPC service to be shut down 1110 * @net: target network namespace 1111 * 1112 * Server threads may still be running (especially in the case where the 1113 * service is still running in other network namespaces). 1114 * 1115 * So we shut down sockets the same way we would on a running server, by 1116 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1117 * the close. In the case there are no such other threads, 1118 * threads running, svc_clean_up_xprts() does a simple version of a 1119 * server's main event loop, and in the case where there are other 1120 * threads, we may need to wait a little while and then check again to 1121 * see if they're done. 1122 */ 1123 void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) 1124 { 1125 int delay = 0; 1126 1127 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1128 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1129 1130 svc_clean_up_xprts(serv, net); 1131 msleep(delay++); 1132 } 1133 } 1134 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); 1135 1136 /* 1137 * Handle defer and revisit of requests 1138 */ 1139 1140 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1141 { 1142 struct svc_deferred_req *dr = 1143 container_of(dreq, struct svc_deferred_req, handle); 1144 struct svc_xprt *xprt = dr->xprt; 1145 1146 spin_lock(&xprt->xpt_lock); 1147 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1148 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1149 spin_unlock(&xprt->xpt_lock); 1150 trace_svc_defer_drop(dr); 1151 free_deferred(xprt, dr); 1152 svc_xprt_put(xprt); 1153 return; 1154 } 1155 dr->xprt = NULL; 1156 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1157 spin_unlock(&xprt->xpt_lock); 1158 trace_svc_defer_queue(dr); 1159 svc_xprt_enqueue(xprt); 1160 svc_xprt_put(xprt); 1161 } 1162 1163 /* 1164 * Save the request off for later processing. The request buffer looks 1165 * like this: 1166 * 1167 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1168 * 1169 * This code can only handle requests that consist of an xprt-header 1170 * and rpc-header. 1171 */ 1172 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1173 { 1174 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1175 struct svc_deferred_req *dr; 1176 1177 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1178 return NULL; /* if more than a page, give up FIXME */ 1179 if (rqstp->rq_deferred) { 1180 dr = rqstp->rq_deferred; 1181 rqstp->rq_deferred = NULL; 1182 } else { 1183 size_t skip; 1184 size_t size; 1185 /* FIXME maybe discard if size too large */ 1186 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1187 dr = kmalloc(size, GFP_KERNEL); 1188 if (dr == NULL) 1189 return NULL; 1190 1191 dr->handle.owner = rqstp->rq_server; 1192 dr->prot = rqstp->rq_prot; 1193 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1194 dr->addrlen = rqstp->rq_addrlen; 1195 dr->daddr = rqstp->rq_daddr; 1196 dr->argslen = rqstp->rq_arg.len >> 2; 1197 1198 /* back up head to the start of the buffer and copy */ 1199 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1200 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1201 dr->argslen << 2); 1202 } 1203 dr->xprt_ctxt = rqstp->rq_xprt_ctxt; 1204 rqstp->rq_xprt_ctxt = NULL; 1205 trace_svc_defer(rqstp); 1206 svc_xprt_get(rqstp->rq_xprt); 1207 dr->xprt = rqstp->rq_xprt; 1208 set_bit(RQ_DROPME, &rqstp->rq_flags); 1209 1210 dr->handle.revisit = svc_revisit; 1211 return &dr->handle; 1212 } 1213 1214 /* 1215 * recv data from a deferred request into an active one 1216 */ 1217 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1218 { 1219 struct svc_deferred_req *dr = rqstp->rq_deferred; 1220 1221 trace_svc_defer_recv(dr); 1222 1223 /* setup iov_base past transport header */ 1224 rqstp->rq_arg.head[0].iov_base = dr->args; 1225 /* The iov_len does not include the transport header bytes */ 1226 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; 1227 rqstp->rq_arg.page_len = 0; 1228 /* The rq_arg.len includes the transport header bytes */ 1229 rqstp->rq_arg.len = dr->argslen << 2; 1230 rqstp->rq_prot = dr->prot; 1231 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1232 rqstp->rq_addrlen = dr->addrlen; 1233 /* Save off transport header len in case we get deferred again */ 1234 rqstp->rq_daddr = dr->daddr; 1235 rqstp->rq_respages = rqstp->rq_pages; 1236 rqstp->rq_xprt_ctxt = dr->xprt_ctxt; 1237 1238 dr->xprt_ctxt = NULL; 1239 svc_xprt_received(rqstp->rq_xprt); 1240 return dr->argslen << 2; 1241 } 1242 1243 1244 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1245 { 1246 struct svc_deferred_req *dr = NULL; 1247 1248 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1249 return NULL; 1250 spin_lock(&xprt->xpt_lock); 1251 if (!list_empty(&xprt->xpt_deferred)) { 1252 dr = list_entry(xprt->xpt_deferred.next, 1253 struct svc_deferred_req, 1254 handle.recent); 1255 list_del_init(&dr->handle.recent); 1256 } else 1257 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1258 spin_unlock(&xprt->xpt_lock); 1259 return dr; 1260 } 1261 1262 /** 1263 * svc_find_xprt - find an RPC transport instance 1264 * @serv: pointer to svc_serv to search 1265 * @xcl_name: C string containing transport's class name 1266 * @net: owner net pointer 1267 * @af: Address family of transport's local address 1268 * @port: transport's IP port number 1269 * 1270 * Return the transport instance pointer for the endpoint accepting 1271 * connections/peer traffic from the specified transport class, 1272 * address family and port. 1273 * 1274 * Specifying 0 for the address family or port is effectively a 1275 * wild-card, and will result in matching the first transport in the 1276 * service's list that has a matching class name. 1277 */ 1278 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1279 struct net *net, const sa_family_t af, 1280 const unsigned short port) 1281 { 1282 struct svc_xprt *xprt; 1283 struct svc_xprt *found = NULL; 1284 1285 /* Sanity check the args */ 1286 if (serv == NULL || xcl_name == NULL) 1287 return found; 1288 1289 spin_lock_bh(&serv->sv_lock); 1290 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1291 if (xprt->xpt_net != net) 1292 continue; 1293 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1294 continue; 1295 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1296 continue; 1297 if (port != 0 && port != svc_xprt_local_port(xprt)) 1298 continue; 1299 found = xprt; 1300 svc_xprt_get(xprt); 1301 break; 1302 } 1303 spin_unlock_bh(&serv->sv_lock); 1304 return found; 1305 } 1306 EXPORT_SYMBOL_GPL(svc_find_xprt); 1307 1308 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1309 char *pos, int remaining) 1310 { 1311 int len; 1312 1313 len = snprintf(pos, remaining, "%s %u\n", 1314 xprt->xpt_class->xcl_name, 1315 svc_xprt_local_port(xprt)); 1316 if (len >= remaining) 1317 return -ENAMETOOLONG; 1318 return len; 1319 } 1320 1321 /** 1322 * svc_xprt_names - format a buffer with a list of transport names 1323 * @serv: pointer to an RPC service 1324 * @buf: pointer to a buffer to be filled in 1325 * @buflen: length of buffer to be filled in 1326 * 1327 * Fills in @buf with a string containing a list of transport names, 1328 * each name terminated with '\n'. 1329 * 1330 * Returns positive length of the filled-in string on success; otherwise 1331 * a negative errno value is returned if an error occurs. 1332 */ 1333 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1334 { 1335 struct svc_xprt *xprt; 1336 int len, totlen; 1337 char *pos; 1338 1339 /* Sanity check args */ 1340 if (!serv) 1341 return 0; 1342 1343 spin_lock_bh(&serv->sv_lock); 1344 1345 pos = buf; 1346 totlen = 0; 1347 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1348 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1349 if (len < 0) { 1350 *buf = '\0'; 1351 totlen = len; 1352 } 1353 if (len <= 0) 1354 break; 1355 1356 pos += len; 1357 totlen += len; 1358 } 1359 1360 spin_unlock_bh(&serv->sv_lock); 1361 return totlen; 1362 } 1363 EXPORT_SYMBOL_GPL(svc_xprt_names); 1364 1365 /*----------------------------------------------------------------------------*/ 1366 1367 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1368 { 1369 unsigned int pidx = (unsigned int)*pos; 1370 struct svc_info *si = m->private; 1371 1372 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1373 1374 mutex_lock(si->mutex); 1375 1376 if (!pidx) 1377 return SEQ_START_TOKEN; 1378 if (!si->serv) 1379 return NULL; 1380 return pidx > si->serv->sv_nrpools ? NULL 1381 : &si->serv->sv_pools[pidx - 1]; 1382 } 1383 1384 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1385 { 1386 struct svc_pool *pool = p; 1387 struct svc_info *si = m->private; 1388 struct svc_serv *serv = si->serv; 1389 1390 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1391 1392 if (!serv) { 1393 pool = NULL; 1394 } else if (p == SEQ_START_TOKEN) { 1395 pool = &serv->sv_pools[0]; 1396 } else { 1397 unsigned int pidx = (pool - &serv->sv_pools[0]); 1398 if (pidx < serv->sv_nrpools-1) 1399 pool = &serv->sv_pools[pidx+1]; 1400 else 1401 pool = NULL; 1402 } 1403 ++*pos; 1404 return pool; 1405 } 1406 1407 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1408 { 1409 struct svc_info *si = m->private; 1410 1411 mutex_unlock(si->mutex); 1412 } 1413 1414 static int svc_pool_stats_show(struct seq_file *m, void *p) 1415 { 1416 struct svc_pool *pool = p; 1417 1418 if (p == SEQ_START_TOKEN) { 1419 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1420 return 0; 1421 } 1422 1423 seq_printf(m, "%u %llu %llu %llu 0\n", 1424 pool->sp_id, 1425 percpu_counter_sum_positive(&pool->sp_messages_arrived), 1426 percpu_counter_sum_positive(&pool->sp_sockets_queued), 1427 percpu_counter_sum_positive(&pool->sp_threads_woken)); 1428 1429 return 0; 1430 } 1431 1432 static const struct seq_operations svc_pool_stats_seq_ops = { 1433 .start = svc_pool_stats_start, 1434 .next = svc_pool_stats_next, 1435 .stop = svc_pool_stats_stop, 1436 .show = svc_pool_stats_show, 1437 }; 1438 1439 int svc_pool_stats_open(struct svc_info *info, struct file *file) 1440 { 1441 struct seq_file *seq; 1442 int err; 1443 1444 err = seq_open(file, &svc_pool_stats_seq_ops); 1445 if (err) 1446 return err; 1447 seq = file->private_data; 1448 seq->private = info; 1449 1450 return 0; 1451 } 1452 EXPORT_SYMBOL(svc_pool_stats_open); 1453 1454 /*----------------------------------------------------------------------------*/ 1455