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 xprt->xpt_ops->xpo_free(xprt); 140 module_put(owner); 141 } 142 143 void svc_xprt_put(struct svc_xprt *xprt) 144 { 145 kref_put(&xprt->xpt_ref, svc_xprt_free); 146 } 147 EXPORT_SYMBOL_GPL(svc_xprt_put); 148 149 /* 150 * Called by transport drivers to initialize the transport independent 151 * portion of the transport instance. 152 */ 153 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 154 struct svc_xprt *xprt, struct svc_serv *serv) 155 { 156 memset(xprt, 0, sizeof(*xprt)); 157 xprt->xpt_class = xcl; 158 xprt->xpt_ops = xcl->xcl_ops; 159 kref_init(&xprt->xpt_ref); 160 xprt->xpt_server = serv; 161 INIT_LIST_HEAD(&xprt->xpt_list); 162 INIT_LIST_HEAD(&xprt->xpt_ready); 163 INIT_LIST_HEAD(&xprt->xpt_deferred); 164 INIT_LIST_HEAD(&xprt->xpt_users); 165 mutex_init(&xprt->xpt_mutex); 166 spin_lock_init(&xprt->xpt_lock); 167 set_bit(XPT_BUSY, &xprt->xpt_flags); 168 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending"); 169 xprt->xpt_net = get_net(net); 170 } 171 EXPORT_SYMBOL_GPL(svc_xprt_init); 172 173 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 174 struct svc_serv *serv, 175 struct net *net, 176 const int family, 177 const unsigned short port, 178 int flags) 179 { 180 struct sockaddr_in sin = { 181 .sin_family = AF_INET, 182 .sin_addr.s_addr = htonl(INADDR_ANY), 183 .sin_port = htons(port), 184 }; 185 #if IS_ENABLED(CONFIG_IPV6) 186 struct sockaddr_in6 sin6 = { 187 .sin6_family = AF_INET6, 188 .sin6_addr = IN6ADDR_ANY_INIT, 189 .sin6_port = htons(port), 190 }; 191 #endif 192 struct sockaddr *sap; 193 size_t len; 194 195 switch (family) { 196 case PF_INET: 197 sap = (struct sockaddr *)&sin; 198 len = sizeof(sin); 199 break; 200 #if IS_ENABLED(CONFIG_IPV6) 201 case PF_INET6: 202 sap = (struct sockaddr *)&sin6; 203 len = sizeof(sin6); 204 break; 205 #endif 206 default: 207 return ERR_PTR(-EAFNOSUPPORT); 208 } 209 210 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 211 } 212 213 /* 214 * svc_xprt_received conditionally queues the transport for processing 215 * by another thread. The caller must hold the XPT_BUSY bit and must 216 * not thereafter touch transport data. 217 * 218 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 219 * insufficient) data. 220 */ 221 static void svc_xprt_received(struct svc_xprt *xprt) 222 { 223 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 224 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 225 return; 226 } 227 228 /* As soon as we clear busy, the xprt could be closed and 229 * 'put', so we need a reference to call svc_enqueue_xprt with: 230 */ 231 svc_xprt_get(xprt); 232 smp_mb__before_atomic(); 233 clear_bit(XPT_BUSY, &xprt->xpt_flags); 234 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 235 svc_xprt_put(xprt); 236 } 237 238 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 239 { 240 clear_bit(XPT_TEMP, &new->xpt_flags); 241 spin_lock_bh(&serv->sv_lock); 242 list_add(&new->xpt_list, &serv->sv_permsocks); 243 spin_unlock_bh(&serv->sv_lock); 244 svc_xprt_received(new); 245 } 246 247 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 248 struct net *net, const int family, 249 const unsigned short port, int flags) 250 { 251 struct svc_xprt_class *xcl; 252 253 dprintk("svc: creating transport %s[%d]\n", xprt_name, port); 254 spin_lock(&svc_xprt_class_lock); 255 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 256 struct svc_xprt *newxprt; 257 unsigned short newport; 258 259 if (strcmp(xprt_name, xcl->xcl_name)) 260 continue; 261 262 if (!try_module_get(xcl->xcl_owner)) 263 goto err; 264 265 spin_unlock(&svc_xprt_class_lock); 266 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 267 if (IS_ERR(newxprt)) { 268 module_put(xcl->xcl_owner); 269 return PTR_ERR(newxprt); 270 } 271 svc_add_new_perm_xprt(serv, newxprt); 272 newport = svc_xprt_local_port(newxprt); 273 return newport; 274 } 275 err: 276 spin_unlock(&svc_xprt_class_lock); 277 dprintk("svc: transport %s not found\n", xprt_name); 278 279 /* This errno is exposed to user space. Provide a reasonable 280 * perror msg for a bad transport. */ 281 return -EPROTONOSUPPORT; 282 } 283 EXPORT_SYMBOL_GPL(svc_create_xprt); 284 285 /* 286 * Copy the local and remote xprt addresses to the rqstp structure 287 */ 288 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 289 { 290 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 291 rqstp->rq_addrlen = xprt->xpt_remotelen; 292 293 /* 294 * Destination address in request is needed for binding the 295 * source address in RPC replies/callbacks later. 296 */ 297 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 298 rqstp->rq_daddrlen = xprt->xpt_locallen; 299 } 300 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 301 302 /** 303 * svc_print_addr - Format rq_addr field for printing 304 * @rqstp: svc_rqst struct containing address to print 305 * @buf: target buffer for formatted address 306 * @len: length of target buffer 307 * 308 */ 309 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 310 { 311 return __svc_print_addr(svc_addr(rqstp), buf, len); 312 } 313 EXPORT_SYMBOL_GPL(svc_print_addr); 314 315 static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) 316 { 317 if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE))) 318 return true; 319 if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED))) 320 return xprt->xpt_ops->xpo_has_wspace(xprt); 321 return false; 322 } 323 324 void svc_xprt_do_enqueue(struct svc_xprt *xprt) 325 { 326 struct svc_pool *pool; 327 struct svc_rqst *rqstp = NULL; 328 int cpu; 329 bool queued = false; 330 331 if (!svc_xprt_has_something_to_do(xprt)) 332 goto out; 333 334 /* Mark transport as busy. It will remain in this state until 335 * the provider calls svc_xprt_received. We update XPT_BUSY 336 * atomically because it also guards against trying to enqueue 337 * the transport twice. 338 */ 339 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { 340 /* Don't enqueue transport while already enqueued */ 341 dprintk("svc: transport %p busy, not enqueued\n", xprt); 342 goto out; 343 } 344 345 cpu = get_cpu(); 346 pool = svc_pool_for_cpu(xprt->xpt_server, cpu); 347 348 atomic_long_inc(&pool->sp_stats.packets); 349 350 redo_search: 351 /* find a thread for this xprt */ 352 rcu_read_lock(); 353 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 354 /* Do a lockless check first */ 355 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 356 continue; 357 358 /* 359 * Once the xprt has been queued, it can only be dequeued by 360 * the task that intends to service it. All we can do at that 361 * point is to try to wake this thread back up so that it can 362 * do so. 363 */ 364 if (!queued) { 365 spin_lock_bh(&rqstp->rq_lock); 366 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) { 367 /* already busy, move on... */ 368 spin_unlock_bh(&rqstp->rq_lock); 369 continue; 370 } 371 372 /* this one will do */ 373 rqstp->rq_xprt = xprt; 374 svc_xprt_get(xprt); 375 spin_unlock_bh(&rqstp->rq_lock); 376 } 377 rcu_read_unlock(); 378 379 atomic_long_inc(&pool->sp_stats.threads_woken); 380 wake_up_process(rqstp->rq_task); 381 put_cpu(); 382 goto out; 383 } 384 rcu_read_unlock(); 385 386 /* 387 * We didn't find an idle thread to use, so we need to queue the xprt. 388 * Do so and then search again. If we find one, we can't hook this one 389 * up to it directly but we can wake the thread up in the hopes that it 390 * will pick it up once it searches for a xprt to service. 391 */ 392 if (!queued) { 393 queued = true; 394 dprintk("svc: transport %p put into queue\n", xprt); 395 spin_lock_bh(&pool->sp_lock); 396 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 397 pool->sp_stats.sockets_queued++; 398 spin_unlock_bh(&pool->sp_lock); 399 goto redo_search; 400 } 401 rqstp = NULL; 402 put_cpu(); 403 out: 404 trace_svc_xprt_do_enqueue(xprt, rqstp); 405 } 406 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); 407 408 /* 409 * Queue up a transport with data pending. If there are idle nfsd 410 * processes, wake 'em up. 411 * 412 */ 413 void svc_xprt_enqueue(struct svc_xprt *xprt) 414 { 415 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) 416 return; 417 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 418 } 419 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 420 421 /* 422 * Dequeue the first transport, if there is one. 423 */ 424 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 425 { 426 struct svc_xprt *xprt = NULL; 427 428 if (list_empty(&pool->sp_sockets)) 429 goto out; 430 431 spin_lock_bh(&pool->sp_lock); 432 if (likely(!list_empty(&pool->sp_sockets))) { 433 xprt = list_first_entry(&pool->sp_sockets, 434 struct svc_xprt, xpt_ready); 435 list_del_init(&xprt->xpt_ready); 436 svc_xprt_get(xprt); 437 438 dprintk("svc: transport %p dequeued, inuse=%d\n", 439 xprt, atomic_read(&xprt->xpt_ref.refcount)); 440 } 441 spin_unlock_bh(&pool->sp_lock); 442 out: 443 trace_svc_xprt_dequeue(xprt); 444 return xprt; 445 } 446 447 /** 448 * svc_reserve - change the space reserved for the reply to a request. 449 * @rqstp: The request in question 450 * @space: new max space to reserve 451 * 452 * Each request reserves some space on the output queue of the transport 453 * to make sure the reply fits. This function reduces that reserved 454 * space to be the amount of space used already, plus @space. 455 * 456 */ 457 void svc_reserve(struct svc_rqst *rqstp, int space) 458 { 459 space += rqstp->rq_res.head[0].iov_len; 460 461 if (space < rqstp->rq_reserved) { 462 struct svc_xprt *xprt = rqstp->rq_xprt; 463 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 464 rqstp->rq_reserved = space; 465 466 if (xprt->xpt_ops->xpo_adjust_wspace) 467 xprt->xpt_ops->xpo_adjust_wspace(xprt); 468 svc_xprt_enqueue(xprt); 469 } 470 } 471 EXPORT_SYMBOL_GPL(svc_reserve); 472 473 static void svc_xprt_release(struct svc_rqst *rqstp) 474 { 475 struct svc_xprt *xprt = rqstp->rq_xprt; 476 477 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 478 479 kfree(rqstp->rq_deferred); 480 rqstp->rq_deferred = NULL; 481 482 svc_free_res_pages(rqstp); 483 rqstp->rq_res.page_len = 0; 484 rqstp->rq_res.page_base = 0; 485 486 /* Reset response buffer and release 487 * the reservation. 488 * But first, check that enough space was reserved 489 * for the reply, otherwise we have a bug! 490 */ 491 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 492 printk(KERN_ERR "RPC request reserved %d but used %d\n", 493 rqstp->rq_reserved, 494 rqstp->rq_res.len); 495 496 rqstp->rq_res.head[0].iov_len = 0; 497 svc_reserve(rqstp, 0); 498 rqstp->rq_xprt = NULL; 499 500 svc_xprt_put(xprt); 501 } 502 503 /* 504 * Some svc_serv's will have occasional work to do, even when a xprt is not 505 * waiting to be serviced. This function is there to "kick" a task in one of 506 * those services so that it can wake up and do that work. Note that we only 507 * bother with pool 0 as we don't need to wake up more than one thread for 508 * this purpose. 509 */ 510 void svc_wake_up(struct svc_serv *serv) 511 { 512 struct svc_rqst *rqstp; 513 struct svc_pool *pool; 514 515 pool = &serv->sv_pools[0]; 516 517 rcu_read_lock(); 518 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 519 /* skip any that aren't queued */ 520 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 521 continue; 522 rcu_read_unlock(); 523 dprintk("svc: daemon %p woken up.\n", rqstp); 524 wake_up_process(rqstp->rq_task); 525 trace_svc_wake_up(rqstp->rq_task->pid); 526 return; 527 } 528 rcu_read_unlock(); 529 530 /* No free entries available */ 531 set_bit(SP_TASK_PENDING, &pool->sp_flags); 532 smp_wmb(); 533 trace_svc_wake_up(0); 534 } 535 EXPORT_SYMBOL_GPL(svc_wake_up); 536 537 int svc_port_is_privileged(struct sockaddr *sin) 538 { 539 switch (sin->sa_family) { 540 case AF_INET: 541 return ntohs(((struct sockaddr_in *)sin)->sin_port) 542 < PROT_SOCK; 543 case AF_INET6: 544 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 545 < PROT_SOCK; 546 default: 547 return 0; 548 } 549 } 550 551 /* 552 * Make sure that we don't have too many active connections. If we have, 553 * something must be dropped. It's not clear what will happen if we allow 554 * "too many" connections, but when dealing with network-facing software, 555 * we have to code defensively. Here we do that by imposing hard limits. 556 * 557 * There's no point in trying to do random drop here for DoS 558 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 559 * attacker can easily beat that. 560 * 561 * The only somewhat efficient mechanism would be if drop old 562 * connections from the same IP first. But right now we don't even 563 * record the client IP in svc_sock. 564 * 565 * single-threaded services that expect a lot of clients will probably 566 * need to set sv_maxconn to override the default value which is based 567 * on the number of threads 568 */ 569 static void svc_check_conn_limits(struct svc_serv *serv) 570 { 571 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 572 (serv->sv_nrthreads+3) * 20; 573 574 if (serv->sv_tmpcnt > limit) { 575 struct svc_xprt *xprt = NULL; 576 spin_lock_bh(&serv->sv_lock); 577 if (!list_empty(&serv->sv_tempsocks)) { 578 /* Try to help the admin */ 579 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 580 serv->sv_name, serv->sv_maxconn ? 581 "max number of connections" : 582 "number of threads"); 583 /* 584 * Always select the oldest connection. It's not fair, 585 * but so is life 586 */ 587 xprt = list_entry(serv->sv_tempsocks.prev, 588 struct svc_xprt, 589 xpt_list); 590 set_bit(XPT_CLOSE, &xprt->xpt_flags); 591 svc_xprt_get(xprt); 592 } 593 spin_unlock_bh(&serv->sv_lock); 594 595 if (xprt) { 596 svc_xprt_enqueue(xprt); 597 svc_xprt_put(xprt); 598 } 599 } 600 } 601 602 static int svc_alloc_arg(struct svc_rqst *rqstp) 603 { 604 struct svc_serv *serv = rqstp->rq_server; 605 struct xdr_buf *arg; 606 int pages; 607 int i; 608 609 /* now allocate needed pages. If we get a failure, sleep briefly */ 610 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; 611 WARN_ON_ONCE(pages >= RPCSVC_MAXPAGES); 612 if (pages >= RPCSVC_MAXPAGES) 613 /* use as many pages as possible */ 614 pages = RPCSVC_MAXPAGES - 1; 615 for (i = 0; i < pages ; i++) 616 while (rqstp->rq_pages[i] == NULL) { 617 struct page *p = alloc_page(GFP_KERNEL); 618 if (!p) { 619 set_current_state(TASK_INTERRUPTIBLE); 620 if (signalled() || kthread_should_stop()) { 621 set_current_state(TASK_RUNNING); 622 return -EINTR; 623 } 624 schedule_timeout(msecs_to_jiffies(500)); 625 } 626 rqstp->rq_pages[i] = p; 627 } 628 rqstp->rq_page_end = &rqstp->rq_pages[i]; 629 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ 630 631 /* Make arg->head point to first page and arg->pages point to rest */ 632 arg = &rqstp->rq_arg; 633 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 634 arg->head[0].iov_len = PAGE_SIZE; 635 arg->pages = rqstp->rq_pages + 1; 636 arg->page_base = 0; 637 /* save at least one page for response */ 638 arg->page_len = (pages-2)*PAGE_SIZE; 639 arg->len = (pages-1)*PAGE_SIZE; 640 arg->tail[0].iov_len = 0; 641 return 0; 642 } 643 644 static bool 645 rqst_should_sleep(struct svc_rqst *rqstp) 646 { 647 struct svc_pool *pool = rqstp->rq_pool; 648 649 /* did someone call svc_wake_up? */ 650 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 651 return false; 652 653 /* was a socket queued? */ 654 if (!list_empty(&pool->sp_sockets)) 655 return false; 656 657 /* are we shutting down? */ 658 if (signalled() || kthread_should_stop()) 659 return false; 660 661 /* are we freezing? */ 662 if (freezing(current)) 663 return false; 664 665 return true; 666 } 667 668 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 669 { 670 struct svc_xprt *xprt; 671 struct svc_pool *pool = rqstp->rq_pool; 672 long time_left = 0; 673 674 /* rq_xprt should be clear on entry */ 675 WARN_ON_ONCE(rqstp->rq_xprt); 676 677 /* Normally we will wait up to 5 seconds for any required 678 * cache information to be provided. 679 */ 680 rqstp->rq_chandle.thread_wait = 5*HZ; 681 682 xprt = svc_xprt_dequeue(pool); 683 if (xprt) { 684 rqstp->rq_xprt = xprt; 685 686 /* As there is a shortage of threads and this request 687 * had to be queued, don't allow the thread to wait so 688 * long for cache updates. 689 */ 690 rqstp->rq_chandle.thread_wait = 1*HZ; 691 clear_bit(SP_TASK_PENDING, &pool->sp_flags); 692 return xprt; 693 } 694 695 /* 696 * We have to be able to interrupt this wait 697 * to bring down the daemons ... 698 */ 699 set_current_state(TASK_INTERRUPTIBLE); 700 clear_bit(RQ_BUSY, &rqstp->rq_flags); 701 smp_mb(); 702 703 if (likely(rqst_should_sleep(rqstp))) 704 time_left = schedule_timeout(timeout); 705 else 706 __set_current_state(TASK_RUNNING); 707 708 try_to_freeze(); 709 710 spin_lock_bh(&rqstp->rq_lock); 711 set_bit(RQ_BUSY, &rqstp->rq_flags); 712 spin_unlock_bh(&rqstp->rq_lock); 713 714 xprt = rqstp->rq_xprt; 715 if (xprt != NULL) 716 return xprt; 717 718 if (!time_left) 719 atomic_long_inc(&pool->sp_stats.threads_timedout); 720 721 if (signalled() || kthread_should_stop()) 722 return ERR_PTR(-EINTR); 723 return ERR_PTR(-EAGAIN); 724 } 725 726 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 727 { 728 spin_lock_bh(&serv->sv_lock); 729 set_bit(XPT_TEMP, &newxpt->xpt_flags); 730 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 731 serv->sv_tmpcnt++; 732 if (serv->sv_temptimer.function == NULL) { 733 /* setup timer to age temp transports */ 734 setup_timer(&serv->sv_temptimer, svc_age_temp_xprts, 735 (unsigned long)serv); 736 mod_timer(&serv->sv_temptimer, 737 jiffies + svc_conn_age_period * HZ); 738 } 739 spin_unlock_bh(&serv->sv_lock); 740 svc_xprt_received(newxpt); 741 } 742 743 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 744 { 745 struct svc_serv *serv = rqstp->rq_server; 746 int len = 0; 747 748 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 749 dprintk("svc_recv: found XPT_CLOSE\n"); 750 svc_delete_xprt(xprt); 751 /* Leave XPT_BUSY set on the dead xprt: */ 752 goto out; 753 } 754 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 755 struct svc_xprt *newxpt; 756 /* 757 * We know this module_get will succeed because the 758 * listener holds a reference too 759 */ 760 __module_get(xprt->xpt_class->xcl_owner); 761 svc_check_conn_limits(xprt->xpt_server); 762 newxpt = xprt->xpt_ops->xpo_accept(xprt); 763 if (newxpt) 764 svc_add_new_temp_xprt(serv, newxpt); 765 else 766 module_put(xprt->xpt_class->xcl_owner); 767 } else { 768 /* XPT_DATA|XPT_DEFERRED case: */ 769 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 770 rqstp, rqstp->rq_pool->sp_id, xprt, 771 atomic_read(&xprt->xpt_ref.refcount)); 772 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 773 if (rqstp->rq_deferred) 774 len = svc_deferred_recv(rqstp); 775 else 776 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 777 dprintk("svc: got len=%d\n", len); 778 rqstp->rq_reserved = serv->sv_max_mesg; 779 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 780 } 781 /* clear XPT_BUSY: */ 782 svc_xprt_received(xprt); 783 out: 784 trace_svc_handle_xprt(xprt, len); 785 return len; 786 } 787 788 /* 789 * Receive the next request on any transport. This code is carefully 790 * organised not to touch any cachelines in the shared svc_serv 791 * structure, only cachelines in the local svc_pool. 792 */ 793 int svc_recv(struct svc_rqst *rqstp, long timeout) 794 { 795 struct svc_xprt *xprt = NULL; 796 struct svc_serv *serv = rqstp->rq_server; 797 int len, err; 798 799 dprintk("svc: server %p waiting for data (to = %ld)\n", 800 rqstp, timeout); 801 802 if (rqstp->rq_xprt) 803 printk(KERN_ERR 804 "svc_recv: service %p, transport not NULL!\n", 805 rqstp); 806 807 err = svc_alloc_arg(rqstp); 808 if (err) 809 goto out; 810 811 try_to_freeze(); 812 cond_resched(); 813 err = -EINTR; 814 if (signalled() || kthread_should_stop()) 815 goto out; 816 817 xprt = svc_get_next_xprt(rqstp, timeout); 818 if (IS_ERR(xprt)) { 819 err = PTR_ERR(xprt); 820 goto out; 821 } 822 823 len = svc_handle_xprt(rqstp, xprt); 824 825 /* No data, incomplete (TCP) read, or accept() */ 826 err = -EAGAIN; 827 if (len <= 0) 828 goto out_release; 829 830 clear_bit(XPT_OLD, &xprt->xpt_flags); 831 832 if (xprt->xpt_ops->xpo_secure_port(rqstp)) 833 set_bit(RQ_SECURE, &rqstp->rq_flags); 834 else 835 clear_bit(RQ_SECURE, &rqstp->rq_flags); 836 rqstp->rq_chandle.defer = svc_defer; 837 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 838 839 if (serv->sv_stats) 840 serv->sv_stats->netcnt++; 841 trace_svc_recv(rqstp, len); 842 return len; 843 out_release: 844 rqstp->rq_res.len = 0; 845 svc_xprt_release(rqstp); 846 out: 847 trace_svc_recv(rqstp, err); 848 return err; 849 } 850 EXPORT_SYMBOL_GPL(svc_recv); 851 852 /* 853 * Drop request 854 */ 855 void svc_drop(struct svc_rqst *rqstp) 856 { 857 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); 858 svc_xprt_release(rqstp); 859 } 860 EXPORT_SYMBOL_GPL(svc_drop); 861 862 /* 863 * Return reply to client. 864 */ 865 int svc_send(struct svc_rqst *rqstp) 866 { 867 struct svc_xprt *xprt; 868 int len = -EFAULT; 869 struct xdr_buf *xb; 870 871 xprt = rqstp->rq_xprt; 872 if (!xprt) 873 goto out; 874 875 /* release the receive skb before sending the reply */ 876 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 877 878 /* calculate over-all length */ 879 xb = &rqstp->rq_res; 880 xb->len = xb->head[0].iov_len + 881 xb->page_len + 882 xb->tail[0].iov_len; 883 884 /* Grab mutex to serialize outgoing data. */ 885 mutex_lock(&xprt->xpt_mutex); 886 if (test_bit(XPT_DEAD, &xprt->xpt_flags) 887 || test_bit(XPT_CLOSE, &xprt->xpt_flags)) 888 len = -ENOTCONN; 889 else 890 len = xprt->xpt_ops->xpo_sendto(rqstp); 891 mutex_unlock(&xprt->xpt_mutex); 892 rpc_wake_up(&xprt->xpt_bc_pending); 893 svc_xprt_release(rqstp); 894 895 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 896 len = 0; 897 out: 898 trace_svc_send(rqstp, len); 899 return len; 900 } 901 902 /* 903 * Timer function to close old temporary transports, using 904 * a mark-and-sweep algorithm. 905 */ 906 static void svc_age_temp_xprts(unsigned long closure) 907 { 908 struct svc_serv *serv = (struct svc_serv *)closure; 909 struct svc_xprt *xprt; 910 struct list_head *le, *next; 911 912 dprintk("svc_age_temp_xprts\n"); 913 914 if (!spin_trylock_bh(&serv->sv_lock)) { 915 /* busy, try again 1 sec later */ 916 dprintk("svc_age_temp_xprts: busy\n"); 917 mod_timer(&serv->sv_temptimer, jiffies + HZ); 918 return; 919 } 920 921 list_for_each_safe(le, next, &serv->sv_tempsocks) { 922 xprt = list_entry(le, struct svc_xprt, xpt_list); 923 924 /* First time through, just mark it OLD. Second time 925 * through, close it. */ 926 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 927 continue; 928 if (atomic_read(&xprt->xpt_ref.refcount) > 1 || 929 test_bit(XPT_BUSY, &xprt->xpt_flags)) 930 continue; 931 list_del_init(le); 932 set_bit(XPT_CLOSE, &xprt->xpt_flags); 933 dprintk("queuing xprt %p for closing\n", xprt); 934 935 /* a thread will dequeue and close it soon */ 936 svc_xprt_enqueue(xprt); 937 } 938 spin_unlock_bh(&serv->sv_lock); 939 940 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 941 } 942 943 /* Close temporary transports whose xpt_local matches server_addr immediately 944 * instead of waiting for them to be picked up by the timer. 945 * 946 * This is meant to be called from a notifier_block that runs when an ip 947 * address is deleted. 948 */ 949 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 950 { 951 struct svc_xprt *xprt; 952 struct svc_sock *svsk; 953 struct socket *sock; 954 struct list_head *le, *next; 955 LIST_HEAD(to_be_closed); 956 struct linger no_linger = { 957 .l_onoff = 1, 958 .l_linger = 0, 959 }; 960 961 spin_lock_bh(&serv->sv_lock); 962 list_for_each_safe(le, next, &serv->sv_tempsocks) { 963 xprt = list_entry(le, struct svc_xprt, xpt_list); 964 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 965 &xprt->xpt_local)) { 966 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 967 list_move(le, &to_be_closed); 968 } 969 } 970 spin_unlock_bh(&serv->sv_lock); 971 972 while (!list_empty(&to_be_closed)) { 973 le = to_be_closed.next; 974 list_del_init(le); 975 xprt = list_entry(le, struct svc_xprt, xpt_list); 976 dprintk("svc_age_temp_xprts_now: closing %p\n", xprt); 977 svsk = container_of(xprt, struct svc_sock, sk_xprt); 978 sock = svsk->sk_sock; 979 kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER, 980 (char *)&no_linger, sizeof(no_linger)); 981 svc_close_xprt(xprt); 982 } 983 } 984 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 985 986 static void call_xpt_users(struct svc_xprt *xprt) 987 { 988 struct svc_xpt_user *u; 989 990 spin_lock(&xprt->xpt_lock); 991 while (!list_empty(&xprt->xpt_users)) { 992 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 993 list_del(&u->list); 994 u->callback(u); 995 } 996 spin_unlock(&xprt->xpt_lock); 997 } 998 999 /* 1000 * Remove a dead transport 1001 */ 1002 static void svc_delete_xprt(struct svc_xprt *xprt) 1003 { 1004 struct svc_serv *serv = xprt->xpt_server; 1005 struct svc_deferred_req *dr; 1006 1007 /* Only do this once */ 1008 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1009 BUG(); 1010 1011 dprintk("svc: svc_delete_xprt(%p)\n", xprt); 1012 xprt->xpt_ops->xpo_detach(xprt); 1013 1014 spin_lock_bh(&serv->sv_lock); 1015 list_del_init(&xprt->xpt_list); 1016 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 1017 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1018 serv->sv_tmpcnt--; 1019 spin_unlock_bh(&serv->sv_lock); 1020 1021 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1022 kfree(dr); 1023 1024 call_xpt_users(xprt); 1025 svc_xprt_put(xprt); 1026 } 1027 1028 void svc_close_xprt(struct svc_xprt *xprt) 1029 { 1030 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1031 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1032 /* someone else will have to effect the close */ 1033 return; 1034 /* 1035 * We expect svc_close_xprt() to work even when no threads are 1036 * running (e.g., while configuring the server before starting 1037 * any threads), so if the transport isn't busy, we delete 1038 * it ourself: 1039 */ 1040 svc_delete_xprt(xprt); 1041 } 1042 EXPORT_SYMBOL_GPL(svc_close_xprt); 1043 1044 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1045 { 1046 struct svc_xprt *xprt; 1047 int ret = 0; 1048 1049 spin_lock(&serv->sv_lock); 1050 list_for_each_entry(xprt, xprt_list, xpt_list) { 1051 if (xprt->xpt_net != net) 1052 continue; 1053 ret++; 1054 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1055 svc_xprt_enqueue(xprt); 1056 } 1057 spin_unlock(&serv->sv_lock); 1058 return ret; 1059 } 1060 1061 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1062 { 1063 struct svc_pool *pool; 1064 struct svc_xprt *xprt; 1065 struct svc_xprt *tmp; 1066 int i; 1067 1068 for (i = 0; i < serv->sv_nrpools; i++) { 1069 pool = &serv->sv_pools[i]; 1070 1071 spin_lock_bh(&pool->sp_lock); 1072 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1073 if (xprt->xpt_net != net) 1074 continue; 1075 list_del_init(&xprt->xpt_ready); 1076 spin_unlock_bh(&pool->sp_lock); 1077 return xprt; 1078 } 1079 spin_unlock_bh(&pool->sp_lock); 1080 } 1081 return NULL; 1082 } 1083 1084 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1085 { 1086 struct svc_xprt *xprt; 1087 1088 while ((xprt = svc_dequeue_net(serv, net))) { 1089 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1090 svc_delete_xprt(xprt); 1091 } 1092 } 1093 1094 /* 1095 * Server threads may still be running (especially in the case where the 1096 * service is still running in other network namespaces). 1097 * 1098 * So we shut down sockets the same way we would on a running server, by 1099 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1100 * the close. In the case there are no such other threads, 1101 * threads running, svc_clean_up_xprts() does a simple version of a 1102 * server's main event loop, and in the case where there are other 1103 * threads, we may need to wait a little while and then check again to 1104 * see if they're done. 1105 */ 1106 void svc_close_net(struct svc_serv *serv, struct net *net) 1107 { 1108 int delay = 0; 1109 1110 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1111 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1112 1113 svc_clean_up_xprts(serv, net); 1114 msleep(delay++); 1115 } 1116 } 1117 1118 /* 1119 * Handle defer and revisit of requests 1120 */ 1121 1122 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1123 { 1124 struct svc_deferred_req *dr = 1125 container_of(dreq, struct svc_deferred_req, handle); 1126 struct svc_xprt *xprt = dr->xprt; 1127 1128 spin_lock(&xprt->xpt_lock); 1129 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1130 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1131 spin_unlock(&xprt->xpt_lock); 1132 dprintk("revisit canceled\n"); 1133 svc_xprt_put(xprt); 1134 kfree(dr); 1135 return; 1136 } 1137 dprintk("revisit queued\n"); 1138 dr->xprt = NULL; 1139 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1140 spin_unlock(&xprt->xpt_lock); 1141 svc_xprt_enqueue(xprt); 1142 svc_xprt_put(xprt); 1143 } 1144 1145 /* 1146 * Save the request off for later processing. The request buffer looks 1147 * like this: 1148 * 1149 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1150 * 1151 * This code can only handle requests that consist of an xprt-header 1152 * and rpc-header. 1153 */ 1154 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1155 { 1156 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1157 struct svc_deferred_req *dr; 1158 1159 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1160 return NULL; /* if more than a page, give up FIXME */ 1161 if (rqstp->rq_deferred) { 1162 dr = rqstp->rq_deferred; 1163 rqstp->rq_deferred = NULL; 1164 } else { 1165 size_t skip; 1166 size_t size; 1167 /* FIXME maybe discard if size too large */ 1168 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1169 dr = kmalloc(size, GFP_KERNEL); 1170 if (dr == NULL) 1171 return NULL; 1172 1173 dr->handle.owner = rqstp->rq_server; 1174 dr->prot = rqstp->rq_prot; 1175 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1176 dr->addrlen = rqstp->rq_addrlen; 1177 dr->daddr = rqstp->rq_daddr; 1178 dr->argslen = rqstp->rq_arg.len >> 2; 1179 dr->xprt_hlen = rqstp->rq_xprt_hlen; 1180 1181 /* back up head to the start of the buffer and copy */ 1182 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1183 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1184 dr->argslen << 2); 1185 } 1186 svc_xprt_get(rqstp->rq_xprt); 1187 dr->xprt = rqstp->rq_xprt; 1188 set_bit(RQ_DROPME, &rqstp->rq_flags); 1189 1190 dr->handle.revisit = svc_revisit; 1191 return &dr->handle; 1192 } 1193 1194 /* 1195 * recv data from a deferred request into an active one 1196 */ 1197 static int svc_deferred_recv(struct svc_rqst *rqstp) 1198 { 1199 struct svc_deferred_req *dr = rqstp->rq_deferred; 1200 1201 /* setup iov_base past transport header */ 1202 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); 1203 /* The iov_len does not include the transport header bytes */ 1204 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; 1205 rqstp->rq_arg.page_len = 0; 1206 /* The rq_arg.len includes the transport header bytes */ 1207 rqstp->rq_arg.len = dr->argslen<<2; 1208 rqstp->rq_prot = dr->prot; 1209 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1210 rqstp->rq_addrlen = dr->addrlen; 1211 /* Save off transport header len in case we get deferred again */ 1212 rqstp->rq_xprt_hlen = dr->xprt_hlen; 1213 rqstp->rq_daddr = dr->daddr; 1214 rqstp->rq_respages = rqstp->rq_pages; 1215 return (dr->argslen<<2) - dr->xprt_hlen; 1216 } 1217 1218 1219 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1220 { 1221 struct svc_deferred_req *dr = NULL; 1222 1223 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1224 return NULL; 1225 spin_lock(&xprt->xpt_lock); 1226 if (!list_empty(&xprt->xpt_deferred)) { 1227 dr = list_entry(xprt->xpt_deferred.next, 1228 struct svc_deferred_req, 1229 handle.recent); 1230 list_del_init(&dr->handle.recent); 1231 } else 1232 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1233 spin_unlock(&xprt->xpt_lock); 1234 return dr; 1235 } 1236 1237 /** 1238 * svc_find_xprt - find an RPC transport instance 1239 * @serv: pointer to svc_serv to search 1240 * @xcl_name: C string containing transport's class name 1241 * @net: owner net pointer 1242 * @af: Address family of transport's local address 1243 * @port: transport's IP port number 1244 * 1245 * Return the transport instance pointer for the endpoint accepting 1246 * connections/peer traffic from the specified transport class, 1247 * address family and port. 1248 * 1249 * Specifying 0 for the address family or port is effectively a 1250 * wild-card, and will result in matching the first transport in the 1251 * service's list that has a matching class name. 1252 */ 1253 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1254 struct net *net, const sa_family_t af, 1255 const unsigned short port) 1256 { 1257 struct svc_xprt *xprt; 1258 struct svc_xprt *found = NULL; 1259 1260 /* Sanity check the args */ 1261 if (serv == NULL || xcl_name == NULL) 1262 return found; 1263 1264 spin_lock_bh(&serv->sv_lock); 1265 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1266 if (xprt->xpt_net != net) 1267 continue; 1268 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1269 continue; 1270 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1271 continue; 1272 if (port != 0 && port != svc_xprt_local_port(xprt)) 1273 continue; 1274 found = xprt; 1275 svc_xprt_get(xprt); 1276 break; 1277 } 1278 spin_unlock_bh(&serv->sv_lock); 1279 return found; 1280 } 1281 EXPORT_SYMBOL_GPL(svc_find_xprt); 1282 1283 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1284 char *pos, int remaining) 1285 { 1286 int len; 1287 1288 len = snprintf(pos, remaining, "%s %u\n", 1289 xprt->xpt_class->xcl_name, 1290 svc_xprt_local_port(xprt)); 1291 if (len >= remaining) 1292 return -ENAMETOOLONG; 1293 return len; 1294 } 1295 1296 /** 1297 * svc_xprt_names - format a buffer with a list of transport names 1298 * @serv: pointer to an RPC service 1299 * @buf: pointer to a buffer to be filled in 1300 * @buflen: length of buffer to be filled in 1301 * 1302 * Fills in @buf with a string containing a list of transport names, 1303 * each name terminated with '\n'. 1304 * 1305 * Returns positive length of the filled-in string on success; otherwise 1306 * a negative errno value is returned if an error occurs. 1307 */ 1308 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1309 { 1310 struct svc_xprt *xprt; 1311 int len, totlen; 1312 char *pos; 1313 1314 /* Sanity check args */ 1315 if (!serv) 1316 return 0; 1317 1318 spin_lock_bh(&serv->sv_lock); 1319 1320 pos = buf; 1321 totlen = 0; 1322 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1323 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1324 if (len < 0) { 1325 *buf = '\0'; 1326 totlen = len; 1327 } 1328 if (len <= 0) 1329 break; 1330 1331 pos += len; 1332 totlen += len; 1333 } 1334 1335 spin_unlock_bh(&serv->sv_lock); 1336 return totlen; 1337 } 1338 EXPORT_SYMBOL_GPL(svc_xprt_names); 1339 1340 1341 /*----------------------------------------------------------------------------*/ 1342 1343 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1344 { 1345 unsigned int pidx = (unsigned int)*pos; 1346 struct svc_serv *serv = m->private; 1347 1348 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1349 1350 if (!pidx) 1351 return SEQ_START_TOKEN; 1352 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1353 } 1354 1355 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1356 { 1357 struct svc_pool *pool = p; 1358 struct svc_serv *serv = m->private; 1359 1360 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1361 1362 if (p == SEQ_START_TOKEN) { 1363 pool = &serv->sv_pools[0]; 1364 } else { 1365 unsigned int pidx = (pool - &serv->sv_pools[0]); 1366 if (pidx < serv->sv_nrpools-1) 1367 pool = &serv->sv_pools[pidx+1]; 1368 else 1369 pool = NULL; 1370 } 1371 ++*pos; 1372 return pool; 1373 } 1374 1375 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1376 { 1377 } 1378 1379 static int svc_pool_stats_show(struct seq_file *m, void *p) 1380 { 1381 struct svc_pool *pool = p; 1382 1383 if (p == SEQ_START_TOKEN) { 1384 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1385 return 0; 1386 } 1387 1388 seq_printf(m, "%u %lu %lu %lu %lu\n", 1389 pool->sp_id, 1390 (unsigned long)atomic_long_read(&pool->sp_stats.packets), 1391 pool->sp_stats.sockets_queued, 1392 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken), 1393 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout)); 1394 1395 return 0; 1396 } 1397 1398 static const struct seq_operations svc_pool_stats_seq_ops = { 1399 .start = svc_pool_stats_start, 1400 .next = svc_pool_stats_next, 1401 .stop = svc_pool_stats_stop, 1402 .show = svc_pool_stats_show, 1403 }; 1404 1405 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1406 { 1407 int err; 1408 1409 err = seq_open(file, &svc_pool_stats_seq_ops); 1410 if (!err) 1411 ((struct seq_file *) file->private_data)->private = serv; 1412 return err; 1413 } 1414 EXPORT_SYMBOL(svc_pool_stats_open); 1415 1416 /*----------------------------------------------------------------------------*/ 1417