1 /* 2 * linux/net/sunrpc/svc_xprt.c 3 * 4 * Author: Tom Tucker <tom@opengridcomputing.com> 5 */ 6 7 #include <linux/sched.h> 8 #include <linux/errno.h> 9 #include <linux/freezer.h> 10 #include <linux/kthread.h> 11 #include <linux/slab.h> 12 #include <net/sock.h> 13 #include <linux/sunrpc/addr.h> 14 #include <linux/sunrpc/stats.h> 15 #include <linux/sunrpc/svc_xprt.h> 16 #include <linux/sunrpc/svcsock.h> 17 #include <linux/sunrpc/xprt.h> 18 #include <linux/module.h> 19 #include <linux/netdevice.h> 20 #include <trace/events/sunrpc.h> 21 22 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 23 24 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); 25 static int svc_deferred_recv(struct svc_rqst *rqstp); 26 static struct cache_deferred_req *svc_defer(struct cache_req *req); 27 static void svc_age_temp_xprts(unsigned long closure); 28 static void svc_delete_xprt(struct svc_xprt *xprt); 29 30 /* apparently the "standard" is that clients close 31 * idle connections after 5 minutes, servers after 32 * 6 minutes 33 * http://www.connectathon.org/talks96/nfstcp.pdf 34 */ 35 static int svc_conn_age_period = 6*60; 36 37 /* List of registered transport classes */ 38 static DEFINE_SPINLOCK(svc_xprt_class_lock); 39 static LIST_HEAD(svc_xprt_class_list); 40 41 /* SMP locking strategy: 42 * 43 * svc_pool->sp_lock protects most of the fields of that pool. 44 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. 45 * when both need to be taken (rare), svc_serv->sv_lock is first. 46 * The "service mutex" protects svc_serv->sv_nrthread. 47 * svc_sock->sk_lock protects the svc_sock->sk_deferred list 48 * and the ->sk_info_authunix cache. 49 * 50 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being 51 * enqueued multiply. During normal transport processing this bit 52 * is set by svc_xprt_enqueue and cleared by svc_xprt_received. 53 * Providers should not manipulate this bit directly. 54 * 55 * Some flags can be set to certain values at any time 56 * providing that certain rules are followed: 57 * 58 * XPT_CONN, XPT_DATA: 59 * - Can be set or cleared at any time. 60 * - After a set, svc_xprt_enqueue must be called to enqueue 61 * the transport for processing. 62 * - After a clear, the transport must be read/accepted. 63 * If this succeeds, it must be set again. 64 * XPT_CLOSE: 65 * - Can set at any time. It is never cleared. 66 * XPT_DEAD: 67 * - Can only be set while XPT_BUSY is held which ensures 68 * that no other thread will be using the transport or will 69 * try to set XPT_DEAD. 70 */ 71 int svc_reg_xprt_class(struct svc_xprt_class *xcl) 72 { 73 struct svc_xprt_class *cl; 74 int res = -EEXIST; 75 76 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); 77 78 INIT_LIST_HEAD(&xcl->xcl_list); 79 spin_lock(&svc_xprt_class_lock); 80 /* Make sure there isn't already a class with the same name */ 81 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { 82 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) 83 goto out; 84 } 85 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); 86 res = 0; 87 out: 88 spin_unlock(&svc_xprt_class_lock); 89 return res; 90 } 91 EXPORT_SYMBOL_GPL(svc_reg_xprt_class); 92 93 void svc_unreg_xprt_class(struct svc_xprt_class *xcl) 94 { 95 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); 96 spin_lock(&svc_xprt_class_lock); 97 list_del_init(&xcl->xcl_list); 98 spin_unlock(&svc_xprt_class_lock); 99 } 100 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); 101 102 /* 103 * Format the transport list for printing 104 */ 105 int svc_print_xprts(char *buf, int maxlen) 106 { 107 struct svc_xprt_class *xcl; 108 char tmpstr[80]; 109 int len = 0; 110 buf[0] = '\0'; 111 112 spin_lock(&svc_xprt_class_lock); 113 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 114 int slen; 115 116 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); 117 slen = strlen(tmpstr); 118 if (len + slen > maxlen) 119 break; 120 len += slen; 121 strcat(buf, tmpstr); 122 } 123 spin_unlock(&svc_xprt_class_lock); 124 125 return len; 126 } 127 128 static void svc_xprt_free(struct kref *kref) 129 { 130 struct svc_xprt *xprt = 131 container_of(kref, struct svc_xprt, xpt_ref); 132 struct module *owner = xprt->xpt_class->xcl_owner; 133 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 134 svcauth_unix_info_release(xprt); 135 put_net(xprt->xpt_net); 136 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 137 if (xprt->xpt_bc_xprt) 138 xprt_put(xprt->xpt_bc_xprt); 139 if (xprt->xpt_bc_xps) 140 xprt_switch_put(xprt->xpt_bc_xps); 141 xprt->xpt_ops->xpo_free(xprt); 142 module_put(owner); 143 } 144 145 void svc_xprt_put(struct svc_xprt *xprt) 146 { 147 kref_put(&xprt->xpt_ref, svc_xprt_free); 148 } 149 EXPORT_SYMBOL_GPL(svc_xprt_put); 150 151 /* 152 * Called by transport drivers to initialize the transport independent 153 * portion of the transport instance. 154 */ 155 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 156 struct svc_xprt *xprt, struct svc_serv *serv) 157 { 158 memset(xprt, 0, sizeof(*xprt)); 159 xprt->xpt_class = xcl; 160 xprt->xpt_ops = xcl->xcl_ops; 161 kref_init(&xprt->xpt_ref); 162 xprt->xpt_server = serv; 163 INIT_LIST_HEAD(&xprt->xpt_list); 164 INIT_LIST_HEAD(&xprt->xpt_ready); 165 INIT_LIST_HEAD(&xprt->xpt_deferred); 166 INIT_LIST_HEAD(&xprt->xpt_users); 167 mutex_init(&xprt->xpt_mutex); 168 spin_lock_init(&xprt->xpt_lock); 169 set_bit(XPT_BUSY, &xprt->xpt_flags); 170 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending"); 171 xprt->xpt_net = get_net(net); 172 } 173 EXPORT_SYMBOL_GPL(svc_xprt_init); 174 175 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 176 struct svc_serv *serv, 177 struct net *net, 178 const int family, 179 const unsigned short port, 180 int flags) 181 { 182 struct sockaddr_in sin = { 183 .sin_family = AF_INET, 184 .sin_addr.s_addr = htonl(INADDR_ANY), 185 .sin_port = htons(port), 186 }; 187 #if IS_ENABLED(CONFIG_IPV6) 188 struct sockaddr_in6 sin6 = { 189 .sin6_family = AF_INET6, 190 .sin6_addr = IN6ADDR_ANY_INIT, 191 .sin6_port = htons(port), 192 }; 193 #endif 194 struct sockaddr *sap; 195 size_t len; 196 197 switch (family) { 198 case PF_INET: 199 sap = (struct sockaddr *)&sin; 200 len = sizeof(sin); 201 break; 202 #if IS_ENABLED(CONFIG_IPV6) 203 case PF_INET6: 204 sap = (struct sockaddr *)&sin6; 205 len = sizeof(sin6); 206 break; 207 #endif 208 default: 209 return ERR_PTR(-EAFNOSUPPORT); 210 } 211 212 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 213 } 214 215 /* 216 * svc_xprt_received conditionally queues the transport for processing 217 * by another thread. The caller must hold the XPT_BUSY bit and must 218 * not thereafter touch transport data. 219 * 220 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 221 * insufficient) data. 222 */ 223 static void svc_xprt_received(struct svc_xprt *xprt) 224 { 225 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 226 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 227 return; 228 } 229 230 /* As soon as we clear busy, the xprt could be closed and 231 * 'put', so we need a reference to call svc_enqueue_xprt with: 232 */ 233 svc_xprt_get(xprt); 234 smp_mb__before_atomic(); 235 clear_bit(XPT_BUSY, &xprt->xpt_flags); 236 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 237 svc_xprt_put(xprt); 238 } 239 240 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 241 { 242 clear_bit(XPT_TEMP, &new->xpt_flags); 243 spin_lock_bh(&serv->sv_lock); 244 list_add(&new->xpt_list, &serv->sv_permsocks); 245 spin_unlock_bh(&serv->sv_lock); 246 svc_xprt_received(new); 247 } 248 249 int _svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 250 struct net *net, const int family, 251 const unsigned short port, int flags) 252 { 253 struct svc_xprt_class *xcl; 254 255 spin_lock(&svc_xprt_class_lock); 256 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 257 struct svc_xprt *newxprt; 258 unsigned short newport; 259 260 if (strcmp(xprt_name, xcl->xcl_name)) 261 continue; 262 263 if (!try_module_get(xcl->xcl_owner)) 264 goto err; 265 266 spin_unlock(&svc_xprt_class_lock); 267 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 268 if (IS_ERR(newxprt)) { 269 module_put(xcl->xcl_owner); 270 return PTR_ERR(newxprt); 271 } 272 svc_add_new_perm_xprt(serv, newxprt); 273 newport = svc_xprt_local_port(newxprt); 274 return newport; 275 } 276 err: 277 spin_unlock(&svc_xprt_class_lock); 278 /* This errno is exposed to user space. Provide a reasonable 279 * perror msg for a bad transport. */ 280 return -EPROTONOSUPPORT; 281 } 282 283 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 284 struct net *net, const int family, 285 const unsigned short port, int flags) 286 { 287 int err; 288 289 dprintk("svc: creating transport %s[%d]\n", xprt_name, port); 290 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags); 291 if (err == -EPROTONOSUPPORT) { 292 request_module("svc%s", xprt_name); 293 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags); 294 } 295 if (err) 296 dprintk("svc: transport %s not found, err %d\n", 297 xprt_name, err); 298 return err; 299 } 300 EXPORT_SYMBOL_GPL(svc_create_xprt); 301 302 /* 303 * Copy the local and remote xprt addresses to the rqstp structure 304 */ 305 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 306 { 307 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 308 rqstp->rq_addrlen = xprt->xpt_remotelen; 309 310 /* 311 * Destination address in request is needed for binding the 312 * source address in RPC replies/callbacks later. 313 */ 314 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 315 rqstp->rq_daddrlen = xprt->xpt_locallen; 316 } 317 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 318 319 /** 320 * svc_print_addr - Format rq_addr field for printing 321 * @rqstp: svc_rqst struct containing address to print 322 * @buf: target buffer for formatted address 323 * @len: length of target buffer 324 * 325 */ 326 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 327 { 328 return __svc_print_addr(svc_addr(rqstp), buf, len); 329 } 330 EXPORT_SYMBOL_GPL(svc_print_addr); 331 332 static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) 333 { 334 if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE))) 335 return true; 336 if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) 337 return xprt->xpt_ops->xpo_has_wspace(xprt); 338 return false; 339 } 340 341 void svc_xprt_do_enqueue(struct svc_xprt *xprt) 342 { 343 struct svc_pool *pool; 344 struct svc_rqst *rqstp = NULL; 345 int cpu; 346 bool queued = false; 347 348 if (!svc_xprt_has_something_to_do(xprt)) 349 goto out; 350 351 /* Mark transport as busy. It will remain in this state until 352 * the provider calls svc_xprt_received. We update XPT_BUSY 353 * atomically because it also guards against trying to enqueue 354 * the transport twice. 355 */ 356 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { 357 /* Don't enqueue transport while already enqueued */ 358 dprintk("svc: transport %p busy, not enqueued\n", xprt); 359 goto out; 360 } 361 362 cpu = get_cpu(); 363 pool = svc_pool_for_cpu(xprt->xpt_server, cpu); 364 365 atomic_long_inc(&pool->sp_stats.packets); 366 367 redo_search: 368 /* find a thread for this xprt */ 369 rcu_read_lock(); 370 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 371 /* Do a lockless check first */ 372 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 373 continue; 374 375 /* 376 * Once the xprt has been queued, it can only be dequeued by 377 * the task that intends to service it. All we can do at that 378 * point is to try to wake this thread back up so that it can 379 * do so. 380 */ 381 if (!queued) { 382 spin_lock_bh(&rqstp->rq_lock); 383 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) { 384 /* already busy, move on... */ 385 spin_unlock_bh(&rqstp->rq_lock); 386 continue; 387 } 388 389 /* this one will do */ 390 rqstp->rq_xprt = xprt; 391 svc_xprt_get(xprt); 392 spin_unlock_bh(&rqstp->rq_lock); 393 } 394 rcu_read_unlock(); 395 396 atomic_long_inc(&pool->sp_stats.threads_woken); 397 wake_up_process(rqstp->rq_task); 398 put_cpu(); 399 goto out; 400 } 401 rcu_read_unlock(); 402 403 /* 404 * We didn't find an idle thread to use, so we need to queue the xprt. 405 * Do so and then search again. If we find one, we can't hook this one 406 * up to it directly but we can wake the thread up in the hopes that it 407 * will pick it up once it searches for a xprt to service. 408 */ 409 if (!queued) { 410 queued = true; 411 dprintk("svc: transport %p put into queue\n", xprt); 412 spin_lock_bh(&pool->sp_lock); 413 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 414 pool->sp_stats.sockets_queued++; 415 spin_unlock_bh(&pool->sp_lock); 416 goto redo_search; 417 } 418 rqstp = NULL; 419 put_cpu(); 420 out: 421 trace_svc_xprt_do_enqueue(xprt, rqstp); 422 } 423 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); 424 425 /* 426 * Queue up a transport with data pending. If there are idle nfsd 427 * processes, wake 'em up. 428 * 429 */ 430 void svc_xprt_enqueue(struct svc_xprt *xprt) 431 { 432 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) 433 return; 434 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 435 } 436 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 437 438 /* 439 * Dequeue the first transport, if there is one. 440 */ 441 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 442 { 443 struct svc_xprt *xprt = NULL; 444 445 if (list_empty(&pool->sp_sockets)) 446 goto out; 447 448 spin_lock_bh(&pool->sp_lock); 449 if (likely(!list_empty(&pool->sp_sockets))) { 450 xprt = list_first_entry(&pool->sp_sockets, 451 struct svc_xprt, xpt_ready); 452 list_del_init(&xprt->xpt_ready); 453 svc_xprt_get(xprt); 454 455 dprintk("svc: transport %p dequeued, inuse=%d\n", 456 xprt, atomic_read(&xprt->xpt_ref.refcount)); 457 } 458 spin_unlock_bh(&pool->sp_lock); 459 out: 460 trace_svc_xprt_dequeue(xprt); 461 return xprt; 462 } 463 464 /** 465 * svc_reserve - change the space reserved for the reply to a request. 466 * @rqstp: The request in question 467 * @space: new max space to reserve 468 * 469 * Each request reserves some space on the output queue of the transport 470 * to make sure the reply fits. This function reduces that reserved 471 * space to be the amount of space used already, plus @space. 472 * 473 */ 474 void svc_reserve(struct svc_rqst *rqstp, int space) 475 { 476 space += rqstp->rq_res.head[0].iov_len; 477 478 if (space < rqstp->rq_reserved) { 479 struct svc_xprt *xprt = rqstp->rq_xprt; 480 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 481 rqstp->rq_reserved = space; 482 483 if (xprt->xpt_ops->xpo_adjust_wspace) 484 xprt->xpt_ops->xpo_adjust_wspace(xprt); 485 svc_xprt_enqueue(xprt); 486 } 487 } 488 EXPORT_SYMBOL_GPL(svc_reserve); 489 490 static void svc_xprt_release(struct svc_rqst *rqstp) 491 { 492 struct svc_xprt *xprt = rqstp->rq_xprt; 493 494 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 495 496 kfree(rqstp->rq_deferred); 497 rqstp->rq_deferred = NULL; 498 499 svc_free_res_pages(rqstp); 500 rqstp->rq_res.page_len = 0; 501 rqstp->rq_res.page_base = 0; 502 503 /* Reset response buffer and release 504 * the reservation. 505 * But first, check that enough space was reserved 506 * for the reply, otherwise we have a bug! 507 */ 508 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 509 printk(KERN_ERR "RPC request reserved %d but used %d\n", 510 rqstp->rq_reserved, 511 rqstp->rq_res.len); 512 513 rqstp->rq_res.head[0].iov_len = 0; 514 svc_reserve(rqstp, 0); 515 rqstp->rq_xprt = NULL; 516 517 svc_xprt_put(xprt); 518 } 519 520 /* 521 * Some svc_serv's will have occasional work to do, even when a xprt is not 522 * waiting to be serviced. This function is there to "kick" a task in one of 523 * those services so that it can wake up and do that work. Note that we only 524 * bother with pool 0 as we don't need to wake up more than one thread for 525 * this purpose. 526 */ 527 void svc_wake_up(struct svc_serv *serv) 528 { 529 struct svc_rqst *rqstp; 530 struct svc_pool *pool; 531 532 pool = &serv->sv_pools[0]; 533 534 rcu_read_lock(); 535 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 536 /* skip any that aren't queued */ 537 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 538 continue; 539 rcu_read_unlock(); 540 dprintk("svc: daemon %p woken up.\n", rqstp); 541 wake_up_process(rqstp->rq_task); 542 trace_svc_wake_up(rqstp->rq_task->pid); 543 return; 544 } 545 rcu_read_unlock(); 546 547 /* No free entries available */ 548 set_bit(SP_TASK_PENDING, &pool->sp_flags); 549 smp_wmb(); 550 trace_svc_wake_up(0); 551 } 552 EXPORT_SYMBOL_GPL(svc_wake_up); 553 554 int svc_port_is_privileged(struct sockaddr *sin) 555 { 556 switch (sin->sa_family) { 557 case AF_INET: 558 return ntohs(((struct sockaddr_in *)sin)->sin_port) 559 < PROT_SOCK; 560 case AF_INET6: 561 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 562 < PROT_SOCK; 563 default: 564 return 0; 565 } 566 } 567 568 /* 569 * Make sure that we don't have too many active connections. If we have, 570 * something must be dropped. It's not clear what will happen if we allow 571 * "too many" connections, but when dealing with network-facing software, 572 * we have to code defensively. Here we do that by imposing hard limits. 573 * 574 * There's no point in trying to do random drop here for DoS 575 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 576 * attacker can easily beat that. 577 * 578 * The only somewhat efficient mechanism would be if drop old 579 * connections from the same IP first. But right now we don't even 580 * record the client IP in svc_sock. 581 * 582 * single-threaded services that expect a lot of clients will probably 583 * need to set sv_maxconn to override the default value which is based 584 * on the number of threads 585 */ 586 static void svc_check_conn_limits(struct svc_serv *serv) 587 { 588 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 589 (serv->sv_nrthreads+3) * 20; 590 591 if (serv->sv_tmpcnt > limit) { 592 struct svc_xprt *xprt = NULL; 593 spin_lock_bh(&serv->sv_lock); 594 if (!list_empty(&serv->sv_tempsocks)) { 595 /* Try to help the admin */ 596 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 597 serv->sv_name, serv->sv_maxconn ? 598 "max number of connections" : 599 "number of threads"); 600 /* 601 * Always select the oldest connection. It's not fair, 602 * but so is life 603 */ 604 xprt = list_entry(serv->sv_tempsocks.prev, 605 struct svc_xprt, 606 xpt_list); 607 set_bit(XPT_CLOSE, &xprt->xpt_flags); 608 svc_xprt_get(xprt); 609 } 610 spin_unlock_bh(&serv->sv_lock); 611 612 if (xprt) { 613 svc_xprt_enqueue(xprt); 614 svc_xprt_put(xprt); 615 } 616 } 617 } 618 619 static int svc_alloc_arg(struct svc_rqst *rqstp) 620 { 621 struct svc_serv *serv = rqstp->rq_server; 622 struct xdr_buf *arg; 623 int pages; 624 int i; 625 626 /* now allocate needed pages. If we get a failure, sleep briefly */ 627 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; 628 WARN_ON_ONCE(pages >= RPCSVC_MAXPAGES); 629 if (pages >= RPCSVC_MAXPAGES) 630 /* use as many pages as possible */ 631 pages = RPCSVC_MAXPAGES - 1; 632 for (i = 0; i < pages ; i++) 633 while (rqstp->rq_pages[i] == NULL) { 634 struct page *p = alloc_page(GFP_KERNEL); 635 if (!p) { 636 set_current_state(TASK_INTERRUPTIBLE); 637 if (signalled() || kthread_should_stop()) { 638 set_current_state(TASK_RUNNING); 639 return -EINTR; 640 } 641 schedule_timeout(msecs_to_jiffies(500)); 642 } 643 rqstp->rq_pages[i] = p; 644 } 645 rqstp->rq_page_end = &rqstp->rq_pages[i]; 646 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ 647 648 /* Make arg->head point to first page and arg->pages point to rest */ 649 arg = &rqstp->rq_arg; 650 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 651 arg->head[0].iov_len = PAGE_SIZE; 652 arg->pages = rqstp->rq_pages + 1; 653 arg->page_base = 0; 654 /* save at least one page for response */ 655 arg->page_len = (pages-2)*PAGE_SIZE; 656 arg->len = (pages-1)*PAGE_SIZE; 657 arg->tail[0].iov_len = 0; 658 return 0; 659 } 660 661 static bool 662 rqst_should_sleep(struct svc_rqst *rqstp) 663 { 664 struct svc_pool *pool = rqstp->rq_pool; 665 666 /* did someone call svc_wake_up? */ 667 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 668 return false; 669 670 /* was a socket queued? */ 671 if (!list_empty(&pool->sp_sockets)) 672 return false; 673 674 /* are we shutting down? */ 675 if (signalled() || kthread_should_stop()) 676 return false; 677 678 /* are we freezing? */ 679 if (freezing(current)) 680 return false; 681 682 return true; 683 } 684 685 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 686 { 687 struct svc_xprt *xprt; 688 struct svc_pool *pool = rqstp->rq_pool; 689 long time_left = 0; 690 691 /* rq_xprt should be clear on entry */ 692 WARN_ON_ONCE(rqstp->rq_xprt); 693 694 /* Normally we will wait up to 5 seconds for any required 695 * cache information to be provided. 696 */ 697 rqstp->rq_chandle.thread_wait = 5*HZ; 698 699 xprt = svc_xprt_dequeue(pool); 700 if (xprt) { 701 rqstp->rq_xprt = xprt; 702 703 /* As there is a shortage of threads and this request 704 * had to be queued, don't allow the thread to wait so 705 * long for cache updates. 706 */ 707 rqstp->rq_chandle.thread_wait = 1*HZ; 708 clear_bit(SP_TASK_PENDING, &pool->sp_flags); 709 return xprt; 710 } 711 712 /* 713 * We have to be able to interrupt this wait 714 * to bring down the daemons ... 715 */ 716 set_current_state(TASK_INTERRUPTIBLE); 717 clear_bit(RQ_BUSY, &rqstp->rq_flags); 718 smp_mb(); 719 720 if (likely(rqst_should_sleep(rqstp))) 721 time_left = schedule_timeout(timeout); 722 else 723 __set_current_state(TASK_RUNNING); 724 725 try_to_freeze(); 726 727 spin_lock_bh(&rqstp->rq_lock); 728 set_bit(RQ_BUSY, &rqstp->rq_flags); 729 spin_unlock_bh(&rqstp->rq_lock); 730 731 xprt = rqstp->rq_xprt; 732 if (xprt != NULL) 733 return xprt; 734 735 if (!time_left) 736 atomic_long_inc(&pool->sp_stats.threads_timedout); 737 738 if (signalled() || kthread_should_stop()) 739 return ERR_PTR(-EINTR); 740 return ERR_PTR(-EAGAIN); 741 } 742 743 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 744 { 745 spin_lock_bh(&serv->sv_lock); 746 set_bit(XPT_TEMP, &newxpt->xpt_flags); 747 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 748 serv->sv_tmpcnt++; 749 if (serv->sv_temptimer.function == NULL) { 750 /* setup timer to age temp transports */ 751 setup_timer(&serv->sv_temptimer, svc_age_temp_xprts, 752 (unsigned long)serv); 753 mod_timer(&serv->sv_temptimer, 754 jiffies + svc_conn_age_period * HZ); 755 } 756 spin_unlock_bh(&serv->sv_lock); 757 svc_xprt_received(newxpt); 758 } 759 760 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 761 { 762 struct svc_serv *serv = rqstp->rq_server; 763 int len = 0; 764 765 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 766 dprintk("svc_recv: found XPT_CLOSE\n"); 767 svc_delete_xprt(xprt); 768 /* Leave XPT_BUSY set on the dead xprt: */ 769 goto out; 770 } 771 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 772 struct svc_xprt *newxpt; 773 /* 774 * We know this module_get will succeed because the 775 * listener holds a reference too 776 */ 777 __module_get(xprt->xpt_class->xcl_owner); 778 svc_check_conn_limits(xprt->xpt_server); 779 newxpt = xprt->xpt_ops->xpo_accept(xprt); 780 if (newxpt) 781 svc_add_new_temp_xprt(serv, newxpt); 782 else 783 module_put(xprt->xpt_class->xcl_owner); 784 } else { 785 /* XPT_DATA|XPT_DEFERRED case: */ 786 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 787 rqstp, rqstp->rq_pool->sp_id, xprt, 788 atomic_read(&xprt->xpt_ref.refcount)); 789 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 790 if (rqstp->rq_deferred) 791 len = svc_deferred_recv(rqstp); 792 else 793 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 794 dprintk("svc: got len=%d\n", len); 795 rqstp->rq_reserved = serv->sv_max_mesg; 796 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 797 } 798 /* clear XPT_BUSY: */ 799 svc_xprt_received(xprt); 800 out: 801 trace_svc_handle_xprt(xprt, len); 802 return len; 803 } 804 805 /* 806 * Receive the next request on any transport. This code is carefully 807 * organised not to touch any cachelines in the shared svc_serv 808 * structure, only cachelines in the local svc_pool. 809 */ 810 int svc_recv(struct svc_rqst *rqstp, long timeout) 811 { 812 struct svc_xprt *xprt = NULL; 813 struct svc_serv *serv = rqstp->rq_server; 814 int len, err; 815 816 dprintk("svc: server %p waiting for data (to = %ld)\n", 817 rqstp, timeout); 818 819 if (rqstp->rq_xprt) 820 printk(KERN_ERR 821 "svc_recv: service %p, transport not NULL!\n", 822 rqstp); 823 824 err = svc_alloc_arg(rqstp); 825 if (err) 826 goto out; 827 828 try_to_freeze(); 829 cond_resched(); 830 err = -EINTR; 831 if (signalled() || kthread_should_stop()) 832 goto out; 833 834 xprt = svc_get_next_xprt(rqstp, timeout); 835 if (IS_ERR(xprt)) { 836 err = PTR_ERR(xprt); 837 goto out; 838 } 839 840 len = svc_handle_xprt(rqstp, xprt); 841 842 /* No data, incomplete (TCP) read, or accept() */ 843 err = -EAGAIN; 844 if (len <= 0) 845 goto out_release; 846 847 clear_bit(XPT_OLD, &xprt->xpt_flags); 848 849 if (xprt->xpt_ops->xpo_secure_port(rqstp)) 850 set_bit(RQ_SECURE, &rqstp->rq_flags); 851 else 852 clear_bit(RQ_SECURE, &rqstp->rq_flags); 853 rqstp->rq_chandle.defer = svc_defer; 854 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 855 856 if (serv->sv_stats) 857 serv->sv_stats->netcnt++; 858 trace_svc_recv(rqstp, len); 859 return len; 860 out_release: 861 rqstp->rq_res.len = 0; 862 svc_xprt_release(rqstp); 863 out: 864 trace_svc_recv(rqstp, err); 865 return err; 866 } 867 EXPORT_SYMBOL_GPL(svc_recv); 868 869 /* 870 * Drop request 871 */ 872 void svc_drop(struct svc_rqst *rqstp) 873 { 874 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); 875 svc_xprt_release(rqstp); 876 } 877 EXPORT_SYMBOL_GPL(svc_drop); 878 879 /* 880 * Return reply to client. 881 */ 882 int svc_send(struct svc_rqst *rqstp) 883 { 884 struct svc_xprt *xprt; 885 int len = -EFAULT; 886 struct xdr_buf *xb; 887 888 xprt = rqstp->rq_xprt; 889 if (!xprt) 890 goto out; 891 892 /* release the receive skb before sending the reply */ 893 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 894 895 /* calculate over-all length */ 896 xb = &rqstp->rq_res; 897 xb->len = xb->head[0].iov_len + 898 xb->page_len + 899 xb->tail[0].iov_len; 900 901 /* Grab mutex to serialize outgoing data. */ 902 mutex_lock(&xprt->xpt_mutex); 903 if (test_bit(XPT_DEAD, &xprt->xpt_flags) 904 || test_bit(XPT_CLOSE, &xprt->xpt_flags)) 905 len = -ENOTCONN; 906 else 907 len = xprt->xpt_ops->xpo_sendto(rqstp); 908 mutex_unlock(&xprt->xpt_mutex); 909 rpc_wake_up(&xprt->xpt_bc_pending); 910 svc_xprt_release(rqstp); 911 912 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 913 len = 0; 914 out: 915 trace_svc_send(rqstp, len); 916 return len; 917 } 918 919 /* 920 * Timer function to close old temporary transports, using 921 * a mark-and-sweep algorithm. 922 */ 923 static void svc_age_temp_xprts(unsigned long closure) 924 { 925 struct svc_serv *serv = (struct svc_serv *)closure; 926 struct svc_xprt *xprt; 927 struct list_head *le, *next; 928 929 dprintk("svc_age_temp_xprts\n"); 930 931 if (!spin_trylock_bh(&serv->sv_lock)) { 932 /* busy, try again 1 sec later */ 933 dprintk("svc_age_temp_xprts: busy\n"); 934 mod_timer(&serv->sv_temptimer, jiffies + HZ); 935 return; 936 } 937 938 list_for_each_safe(le, next, &serv->sv_tempsocks) { 939 xprt = list_entry(le, struct svc_xprt, xpt_list); 940 941 /* First time through, just mark it OLD. Second time 942 * through, close it. */ 943 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 944 continue; 945 if (atomic_read(&xprt->xpt_ref.refcount) > 1 || 946 test_bit(XPT_BUSY, &xprt->xpt_flags)) 947 continue; 948 list_del_init(le); 949 set_bit(XPT_CLOSE, &xprt->xpt_flags); 950 dprintk("queuing xprt %p for closing\n", xprt); 951 952 /* a thread will dequeue and close it soon */ 953 svc_xprt_enqueue(xprt); 954 } 955 spin_unlock_bh(&serv->sv_lock); 956 957 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 958 } 959 960 /* Close temporary transports whose xpt_local matches server_addr immediately 961 * instead of waiting for them to be picked up by the timer. 962 * 963 * This is meant to be called from a notifier_block that runs when an ip 964 * address is deleted. 965 */ 966 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 967 { 968 struct svc_xprt *xprt; 969 struct svc_sock *svsk; 970 struct socket *sock; 971 struct list_head *le, *next; 972 LIST_HEAD(to_be_closed); 973 struct linger no_linger = { 974 .l_onoff = 1, 975 .l_linger = 0, 976 }; 977 978 spin_lock_bh(&serv->sv_lock); 979 list_for_each_safe(le, next, &serv->sv_tempsocks) { 980 xprt = list_entry(le, struct svc_xprt, xpt_list); 981 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 982 &xprt->xpt_local)) { 983 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 984 list_move(le, &to_be_closed); 985 } 986 } 987 spin_unlock_bh(&serv->sv_lock); 988 989 while (!list_empty(&to_be_closed)) { 990 le = to_be_closed.next; 991 list_del_init(le); 992 xprt = list_entry(le, struct svc_xprt, xpt_list); 993 dprintk("svc_age_temp_xprts_now: closing %p\n", xprt); 994 svsk = container_of(xprt, struct svc_sock, sk_xprt); 995 sock = svsk->sk_sock; 996 kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER, 997 (char *)&no_linger, sizeof(no_linger)); 998 svc_close_xprt(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(&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 /* Only do this once */ 1025 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1026 BUG(); 1027 1028 dprintk("svc: svc_delete_xprt(%p)\n", xprt); 1029 xprt->xpt_ops->xpo_detach(xprt); 1030 1031 spin_lock_bh(&serv->sv_lock); 1032 list_del_init(&xprt->xpt_list); 1033 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 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 kfree(dr); 1040 1041 call_xpt_users(xprt); 1042 svc_xprt_put(xprt); 1043 } 1044 1045 void svc_close_xprt(struct svc_xprt *xprt) 1046 { 1047 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1048 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1049 /* someone else will have to effect the close */ 1050 return; 1051 /* 1052 * We expect svc_close_xprt() to work even when no threads are 1053 * running (e.g., while configuring the server before starting 1054 * any threads), so if the transport isn't busy, we delete 1055 * it ourself: 1056 */ 1057 svc_delete_xprt(xprt); 1058 } 1059 EXPORT_SYMBOL_GPL(svc_close_xprt); 1060 1061 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1062 { 1063 struct svc_xprt *xprt; 1064 int ret = 0; 1065 1066 spin_lock(&serv->sv_lock); 1067 list_for_each_entry(xprt, xprt_list, xpt_list) { 1068 if (xprt->xpt_net != net) 1069 continue; 1070 ret++; 1071 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1072 svc_xprt_enqueue(xprt); 1073 } 1074 spin_unlock(&serv->sv_lock); 1075 return ret; 1076 } 1077 1078 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1079 { 1080 struct svc_pool *pool; 1081 struct svc_xprt *xprt; 1082 struct svc_xprt *tmp; 1083 int i; 1084 1085 for (i = 0; i < serv->sv_nrpools; i++) { 1086 pool = &serv->sv_pools[i]; 1087 1088 spin_lock_bh(&pool->sp_lock); 1089 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1090 if (xprt->xpt_net != net) 1091 continue; 1092 list_del_init(&xprt->xpt_ready); 1093 spin_unlock_bh(&pool->sp_lock); 1094 return xprt; 1095 } 1096 spin_unlock_bh(&pool->sp_lock); 1097 } 1098 return NULL; 1099 } 1100 1101 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1102 { 1103 struct svc_xprt *xprt; 1104 1105 while ((xprt = svc_dequeue_net(serv, net))) { 1106 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1107 svc_delete_xprt(xprt); 1108 } 1109 } 1110 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_close_net(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 1135 /* 1136 * Handle defer and revisit of requests 1137 */ 1138 1139 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1140 { 1141 struct svc_deferred_req *dr = 1142 container_of(dreq, struct svc_deferred_req, handle); 1143 struct svc_xprt *xprt = dr->xprt; 1144 1145 spin_lock(&xprt->xpt_lock); 1146 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1147 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1148 spin_unlock(&xprt->xpt_lock); 1149 dprintk("revisit canceled\n"); 1150 svc_xprt_put(xprt); 1151 kfree(dr); 1152 return; 1153 } 1154 dprintk("revisit queued\n"); 1155 dr->xprt = NULL; 1156 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1157 spin_unlock(&xprt->xpt_lock); 1158 svc_xprt_enqueue(xprt); 1159 svc_xprt_put(xprt); 1160 } 1161 1162 /* 1163 * Save the request off for later processing. The request buffer looks 1164 * like this: 1165 * 1166 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1167 * 1168 * This code can only handle requests that consist of an xprt-header 1169 * and rpc-header. 1170 */ 1171 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1172 { 1173 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1174 struct svc_deferred_req *dr; 1175 1176 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1177 return NULL; /* if more than a page, give up FIXME */ 1178 if (rqstp->rq_deferred) { 1179 dr = rqstp->rq_deferred; 1180 rqstp->rq_deferred = NULL; 1181 } else { 1182 size_t skip; 1183 size_t size; 1184 /* FIXME maybe discard if size too large */ 1185 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1186 dr = kmalloc(size, GFP_KERNEL); 1187 if (dr == NULL) 1188 return NULL; 1189 1190 dr->handle.owner = rqstp->rq_server; 1191 dr->prot = rqstp->rq_prot; 1192 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1193 dr->addrlen = rqstp->rq_addrlen; 1194 dr->daddr = rqstp->rq_daddr; 1195 dr->argslen = rqstp->rq_arg.len >> 2; 1196 dr->xprt_hlen = rqstp->rq_xprt_hlen; 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 svc_xprt_get(rqstp->rq_xprt); 1204 dr->xprt = rqstp->rq_xprt; 1205 set_bit(RQ_DROPME, &rqstp->rq_flags); 1206 1207 dr->handle.revisit = svc_revisit; 1208 return &dr->handle; 1209 } 1210 1211 /* 1212 * recv data from a deferred request into an active one 1213 */ 1214 static int svc_deferred_recv(struct svc_rqst *rqstp) 1215 { 1216 struct svc_deferred_req *dr = rqstp->rq_deferred; 1217 1218 /* setup iov_base past transport header */ 1219 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); 1220 /* The iov_len does not include the transport header bytes */ 1221 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; 1222 rqstp->rq_arg.page_len = 0; 1223 /* The rq_arg.len includes the transport header bytes */ 1224 rqstp->rq_arg.len = dr->argslen<<2; 1225 rqstp->rq_prot = dr->prot; 1226 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1227 rqstp->rq_addrlen = dr->addrlen; 1228 /* Save off transport header len in case we get deferred again */ 1229 rqstp->rq_xprt_hlen = dr->xprt_hlen; 1230 rqstp->rq_daddr = dr->daddr; 1231 rqstp->rq_respages = rqstp->rq_pages; 1232 return (dr->argslen<<2) - dr->xprt_hlen; 1233 } 1234 1235 1236 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1237 { 1238 struct svc_deferred_req *dr = NULL; 1239 1240 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1241 return NULL; 1242 spin_lock(&xprt->xpt_lock); 1243 if (!list_empty(&xprt->xpt_deferred)) { 1244 dr = list_entry(xprt->xpt_deferred.next, 1245 struct svc_deferred_req, 1246 handle.recent); 1247 list_del_init(&dr->handle.recent); 1248 } else 1249 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1250 spin_unlock(&xprt->xpt_lock); 1251 return dr; 1252 } 1253 1254 /** 1255 * svc_find_xprt - find an RPC transport instance 1256 * @serv: pointer to svc_serv to search 1257 * @xcl_name: C string containing transport's class name 1258 * @net: owner net pointer 1259 * @af: Address family of transport's local address 1260 * @port: transport's IP port number 1261 * 1262 * Return the transport instance pointer for the endpoint accepting 1263 * connections/peer traffic from the specified transport class, 1264 * address family and port. 1265 * 1266 * Specifying 0 for the address family or port is effectively a 1267 * wild-card, and will result in matching the first transport in the 1268 * service's list that has a matching class name. 1269 */ 1270 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1271 struct net *net, const sa_family_t af, 1272 const unsigned short port) 1273 { 1274 struct svc_xprt *xprt; 1275 struct svc_xprt *found = NULL; 1276 1277 /* Sanity check the args */ 1278 if (serv == NULL || xcl_name == NULL) 1279 return found; 1280 1281 spin_lock_bh(&serv->sv_lock); 1282 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1283 if (xprt->xpt_net != net) 1284 continue; 1285 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1286 continue; 1287 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1288 continue; 1289 if (port != 0 && port != svc_xprt_local_port(xprt)) 1290 continue; 1291 found = xprt; 1292 svc_xprt_get(xprt); 1293 break; 1294 } 1295 spin_unlock_bh(&serv->sv_lock); 1296 return found; 1297 } 1298 EXPORT_SYMBOL_GPL(svc_find_xprt); 1299 1300 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1301 char *pos, int remaining) 1302 { 1303 int len; 1304 1305 len = snprintf(pos, remaining, "%s %u\n", 1306 xprt->xpt_class->xcl_name, 1307 svc_xprt_local_port(xprt)); 1308 if (len >= remaining) 1309 return -ENAMETOOLONG; 1310 return len; 1311 } 1312 1313 /** 1314 * svc_xprt_names - format a buffer with a list of transport names 1315 * @serv: pointer to an RPC service 1316 * @buf: pointer to a buffer to be filled in 1317 * @buflen: length of buffer to be filled in 1318 * 1319 * Fills in @buf with a string containing a list of transport names, 1320 * each name terminated with '\n'. 1321 * 1322 * Returns positive length of the filled-in string on success; otherwise 1323 * a negative errno value is returned if an error occurs. 1324 */ 1325 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1326 { 1327 struct svc_xprt *xprt; 1328 int len, totlen; 1329 char *pos; 1330 1331 /* Sanity check args */ 1332 if (!serv) 1333 return 0; 1334 1335 spin_lock_bh(&serv->sv_lock); 1336 1337 pos = buf; 1338 totlen = 0; 1339 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1340 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1341 if (len < 0) { 1342 *buf = '\0'; 1343 totlen = len; 1344 } 1345 if (len <= 0) 1346 break; 1347 1348 pos += len; 1349 totlen += len; 1350 } 1351 1352 spin_unlock_bh(&serv->sv_lock); 1353 return totlen; 1354 } 1355 EXPORT_SYMBOL_GPL(svc_xprt_names); 1356 1357 1358 /*----------------------------------------------------------------------------*/ 1359 1360 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1361 { 1362 unsigned int pidx = (unsigned int)*pos; 1363 struct svc_serv *serv = m->private; 1364 1365 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1366 1367 if (!pidx) 1368 return SEQ_START_TOKEN; 1369 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1370 } 1371 1372 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1373 { 1374 struct svc_pool *pool = p; 1375 struct svc_serv *serv = m->private; 1376 1377 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1378 1379 if (p == SEQ_START_TOKEN) { 1380 pool = &serv->sv_pools[0]; 1381 } else { 1382 unsigned int pidx = (pool - &serv->sv_pools[0]); 1383 if (pidx < serv->sv_nrpools-1) 1384 pool = &serv->sv_pools[pidx+1]; 1385 else 1386 pool = NULL; 1387 } 1388 ++*pos; 1389 return pool; 1390 } 1391 1392 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1393 { 1394 } 1395 1396 static int svc_pool_stats_show(struct seq_file *m, void *p) 1397 { 1398 struct svc_pool *pool = p; 1399 1400 if (p == SEQ_START_TOKEN) { 1401 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1402 return 0; 1403 } 1404 1405 seq_printf(m, "%u %lu %lu %lu %lu\n", 1406 pool->sp_id, 1407 (unsigned long)atomic_long_read(&pool->sp_stats.packets), 1408 pool->sp_stats.sockets_queued, 1409 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken), 1410 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout)); 1411 1412 return 0; 1413 } 1414 1415 static const struct seq_operations svc_pool_stats_seq_ops = { 1416 .start = svc_pool_stats_start, 1417 .next = svc_pool_stats_next, 1418 .stop = svc_pool_stats_stop, 1419 .show = svc_pool_stats_show, 1420 }; 1421 1422 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1423 { 1424 int err; 1425 1426 err = seq_open(file, &svc_pool_stats_seq_ops); 1427 if (!err) 1428 ((struct seq_file *) file->private_data)->private = serv; 1429 return err; 1430 } 1431 EXPORT_SYMBOL(svc_pool_stats_open); 1432 1433 /*----------------------------------------------------------------------------*/ 1434