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/stats.h> 14 #include <linux/sunrpc/svc_xprt.h> 15 #include <linux/sunrpc/svcsock.h> 16 #include <linux/sunrpc/xprt.h> 17 #include <linux/module.h> 18 #include <trace/events/sunrpc.h> 19 20 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 21 22 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); 23 static int svc_deferred_recv(struct svc_rqst *rqstp); 24 static struct cache_deferred_req *svc_defer(struct cache_req *req); 25 static void svc_age_temp_xprts(unsigned long closure); 26 static void svc_delete_xprt(struct svc_xprt *xprt); 27 static void svc_xprt_do_enqueue(struct svc_xprt *xprt); 28 29 /* apparently the "standard" is that clients close 30 * idle connections after 5 minutes, servers after 31 * 6 minutes 32 * http://www.connectathon.org/talks96/nfstcp.pdf 33 */ 34 static int svc_conn_age_period = 6*60; 35 36 /* List of registered transport classes */ 37 static DEFINE_SPINLOCK(svc_xprt_class_lock); 38 static LIST_HEAD(svc_xprt_class_list); 39 40 /* SMP locking strategy: 41 * 42 * svc_pool->sp_lock protects most of the fields of that pool. 43 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. 44 * when both need to be taken (rare), svc_serv->sv_lock is first. 45 * BKL protects svc_serv->sv_nrthread. 46 * svc_sock->sk_lock protects the svc_sock->sk_deferred list 47 * and the ->sk_info_authunix cache. 48 * 49 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being 50 * enqueued multiply. During normal transport processing this bit 51 * is set by svc_xprt_enqueue and cleared by svc_xprt_received. 52 * Providers should not manipulate this bit directly. 53 * 54 * Some flags can be set to certain values at any time 55 * providing that certain rules are followed: 56 * 57 * XPT_CONN, XPT_DATA: 58 * - Can be set or cleared at any time. 59 * - After a set, svc_xprt_enqueue must be called to enqueue 60 * the transport for processing. 61 * - After a clear, the transport must be read/accepted. 62 * If this succeeds, it must be set again. 63 * XPT_CLOSE: 64 * - Can set at any time. It is never cleared. 65 * XPT_DEAD: 66 * - Can only be set while XPT_BUSY is held which ensures 67 * that no other thread will be using the transport or will 68 * try to set XPT_DEAD. 69 */ 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 WARN_ON_ONCE(!test_bit(XPT_BUSY, &xprt->xpt_flags)); 224 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) 225 return; 226 /* As soon as we clear busy, the xprt could be closed and 227 * 'put', so we need a reference to call svc_xprt_do_enqueue with: 228 */ 229 svc_xprt_get(xprt); 230 smp_mb__before_atomic(); 231 clear_bit(XPT_BUSY, &xprt->xpt_flags); 232 svc_xprt_do_enqueue(xprt); 233 svc_xprt_put(xprt); 234 } 235 236 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 237 { 238 clear_bit(XPT_TEMP, &new->xpt_flags); 239 spin_lock_bh(&serv->sv_lock); 240 list_add(&new->xpt_list, &serv->sv_permsocks); 241 spin_unlock_bh(&serv->sv_lock); 242 svc_xprt_received(new); 243 } 244 245 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 246 struct net *net, const int family, 247 const unsigned short port, int flags) 248 { 249 struct svc_xprt_class *xcl; 250 251 dprintk("svc: creating transport %s[%d]\n", xprt_name, port); 252 spin_lock(&svc_xprt_class_lock); 253 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 254 struct svc_xprt *newxprt; 255 unsigned short newport; 256 257 if (strcmp(xprt_name, xcl->xcl_name)) 258 continue; 259 260 if (!try_module_get(xcl->xcl_owner)) 261 goto err; 262 263 spin_unlock(&svc_xprt_class_lock); 264 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 265 if (IS_ERR(newxprt)) { 266 module_put(xcl->xcl_owner); 267 return PTR_ERR(newxprt); 268 } 269 svc_add_new_perm_xprt(serv, newxprt); 270 newport = svc_xprt_local_port(newxprt); 271 return newport; 272 } 273 err: 274 spin_unlock(&svc_xprt_class_lock); 275 dprintk("svc: transport %s not found\n", xprt_name); 276 277 /* This errno is exposed to user space. Provide a reasonable 278 * perror msg for a bad transport. */ 279 return -EPROTONOSUPPORT; 280 } 281 EXPORT_SYMBOL_GPL(svc_create_xprt); 282 283 /* 284 * Copy the local and remote xprt addresses to the rqstp structure 285 */ 286 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 287 { 288 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 289 rqstp->rq_addrlen = xprt->xpt_remotelen; 290 291 /* 292 * Destination address in request is needed for binding the 293 * source address in RPC replies/callbacks later. 294 */ 295 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 296 rqstp->rq_daddrlen = xprt->xpt_locallen; 297 } 298 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 299 300 /** 301 * svc_print_addr - Format rq_addr field for printing 302 * @rqstp: svc_rqst struct containing address to print 303 * @buf: target buffer for formatted address 304 * @len: length of target buffer 305 * 306 */ 307 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 308 { 309 return __svc_print_addr(svc_addr(rqstp), buf, len); 310 } 311 EXPORT_SYMBOL_GPL(svc_print_addr); 312 313 /* 314 * Queue up an idle server thread. Must have pool->sp_lock held. 315 * Note: this is really a stack rather than a queue, so that we only 316 * use as many different threads as we need, and the rest don't pollute 317 * the cache. 318 */ 319 static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) 320 { 321 list_add(&rqstp->rq_list, &pool->sp_threads); 322 } 323 324 /* 325 * Dequeue an nfsd thread. Must have pool->sp_lock held. 326 */ 327 static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) 328 { 329 list_del(&rqstp->rq_list); 330 } 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 static void svc_xprt_do_enqueue(struct svc_xprt *xprt) 342 { 343 struct svc_pool *pool; 344 struct svc_rqst *rqstp; 345 int cpu; 346 347 if (!svc_xprt_has_something_to_do(xprt)) 348 return; 349 350 /* Mark transport as busy. It will remain in this state until 351 * the provider calls svc_xprt_received. We update XPT_BUSY 352 * atomically because it also guards against trying to enqueue 353 * the transport twice. 354 */ 355 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { 356 /* Don't enqueue transport while already enqueued */ 357 dprintk("svc: transport %p busy, not enqueued\n", xprt); 358 return; 359 } 360 361 cpu = get_cpu(); 362 pool = svc_pool_for_cpu(xprt->xpt_server, cpu); 363 spin_lock_bh(&pool->sp_lock); 364 365 pool->sp_stats.packets++; 366 367 if (!list_empty(&pool->sp_threads)) { 368 rqstp = list_entry(pool->sp_threads.next, 369 struct svc_rqst, 370 rq_list); 371 dprintk("svc: transport %p served by daemon %p\n", 372 xprt, rqstp); 373 svc_thread_dequeue(pool, rqstp); 374 if (rqstp->rq_xprt) 375 printk(KERN_ERR 376 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", 377 rqstp, rqstp->rq_xprt); 378 /* Note the order of the following 3 lines: 379 * We want to assign xprt to rqstp->rq_xprt only _after_ 380 * we've woken up the process, so that we don't race with 381 * the lockless check in svc_get_next_xprt(). 382 */ 383 svc_xprt_get(xprt); 384 wake_up_process(rqstp->rq_task); 385 rqstp->rq_xprt = xprt; 386 pool->sp_stats.threads_woken++; 387 } else { 388 dprintk("svc: transport %p put into queue\n", xprt); 389 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 390 pool->sp_stats.sockets_queued++; 391 } 392 393 spin_unlock_bh(&pool->sp_lock); 394 put_cpu(); 395 } 396 397 /* 398 * Queue up a transport with data pending. If there are idle nfsd 399 * processes, wake 'em up. 400 * 401 */ 402 void svc_xprt_enqueue(struct svc_xprt *xprt) 403 { 404 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) 405 return; 406 svc_xprt_do_enqueue(xprt); 407 } 408 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 409 410 /* 411 * Dequeue the first transport. Must be called with the pool->sp_lock held. 412 */ 413 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 414 { 415 struct svc_xprt *xprt; 416 417 if (list_empty(&pool->sp_sockets)) 418 return NULL; 419 420 xprt = list_entry(pool->sp_sockets.next, 421 struct svc_xprt, xpt_ready); 422 list_del_init(&xprt->xpt_ready); 423 424 dprintk("svc: transport %p dequeued, inuse=%d\n", 425 xprt, atomic_read(&xprt->xpt_ref.refcount)); 426 427 return xprt; 428 } 429 430 /** 431 * svc_reserve - change the space reserved for the reply to a request. 432 * @rqstp: The request in question 433 * @space: new max space to reserve 434 * 435 * Each request reserves some space on the output queue of the transport 436 * to make sure the reply fits. This function reduces that reserved 437 * space to be the amount of space used already, plus @space. 438 * 439 */ 440 void svc_reserve(struct svc_rqst *rqstp, int space) 441 { 442 space += rqstp->rq_res.head[0].iov_len; 443 444 if (space < rqstp->rq_reserved) { 445 struct svc_xprt *xprt = rqstp->rq_xprt; 446 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 447 rqstp->rq_reserved = space; 448 449 if (xprt->xpt_ops->xpo_adjust_wspace) 450 xprt->xpt_ops->xpo_adjust_wspace(xprt); 451 svc_xprt_enqueue(xprt); 452 } 453 } 454 EXPORT_SYMBOL_GPL(svc_reserve); 455 456 static void svc_xprt_release(struct svc_rqst *rqstp) 457 { 458 struct svc_xprt *xprt = rqstp->rq_xprt; 459 460 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 461 462 kfree(rqstp->rq_deferred); 463 rqstp->rq_deferred = NULL; 464 465 svc_free_res_pages(rqstp); 466 rqstp->rq_res.page_len = 0; 467 rqstp->rq_res.page_base = 0; 468 469 /* Reset response buffer and release 470 * the reservation. 471 * But first, check that enough space was reserved 472 * for the reply, otherwise we have a bug! 473 */ 474 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 475 printk(KERN_ERR "RPC request reserved %d but used %d\n", 476 rqstp->rq_reserved, 477 rqstp->rq_res.len); 478 479 rqstp->rq_res.head[0].iov_len = 0; 480 svc_reserve(rqstp, 0); 481 rqstp->rq_xprt = NULL; 482 483 svc_xprt_put(xprt); 484 } 485 486 /* 487 * External function to wake up a server waiting for data 488 * This really only makes sense for services like lockd 489 * which have exactly one thread anyway. 490 */ 491 void svc_wake_up(struct svc_serv *serv) 492 { 493 struct svc_rqst *rqstp; 494 unsigned int i; 495 struct svc_pool *pool; 496 497 for (i = 0; i < serv->sv_nrpools; i++) { 498 pool = &serv->sv_pools[i]; 499 500 spin_lock_bh(&pool->sp_lock); 501 if (!list_empty(&pool->sp_threads)) { 502 rqstp = list_entry(pool->sp_threads.next, 503 struct svc_rqst, 504 rq_list); 505 dprintk("svc: daemon %p woken up.\n", rqstp); 506 /* 507 svc_thread_dequeue(pool, rqstp); 508 rqstp->rq_xprt = NULL; 509 */ 510 wake_up_process(rqstp->rq_task); 511 } else 512 pool->sp_task_pending = 1; 513 spin_unlock_bh(&pool->sp_lock); 514 } 515 } 516 EXPORT_SYMBOL_GPL(svc_wake_up); 517 518 int svc_port_is_privileged(struct sockaddr *sin) 519 { 520 switch (sin->sa_family) { 521 case AF_INET: 522 return ntohs(((struct sockaddr_in *)sin)->sin_port) 523 < PROT_SOCK; 524 case AF_INET6: 525 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 526 < PROT_SOCK; 527 default: 528 return 0; 529 } 530 } 531 532 /* 533 * Make sure that we don't have too many active connections. If we have, 534 * something must be dropped. It's not clear what will happen if we allow 535 * "too many" connections, but when dealing with network-facing software, 536 * we have to code defensively. Here we do that by imposing hard limits. 537 * 538 * There's no point in trying to do random drop here for DoS 539 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 540 * attacker can easily beat that. 541 * 542 * The only somewhat efficient mechanism would be if drop old 543 * connections from the same IP first. But right now we don't even 544 * record the client IP in svc_sock. 545 * 546 * single-threaded services that expect a lot of clients will probably 547 * need to set sv_maxconn to override the default value which is based 548 * on the number of threads 549 */ 550 static void svc_check_conn_limits(struct svc_serv *serv) 551 { 552 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 553 (serv->sv_nrthreads+3) * 20; 554 555 if (serv->sv_tmpcnt > limit) { 556 struct svc_xprt *xprt = NULL; 557 spin_lock_bh(&serv->sv_lock); 558 if (!list_empty(&serv->sv_tempsocks)) { 559 /* Try to help the admin */ 560 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 561 serv->sv_name, serv->sv_maxconn ? 562 "max number of connections" : 563 "number of threads"); 564 /* 565 * Always select the oldest connection. It's not fair, 566 * but so is life 567 */ 568 xprt = list_entry(serv->sv_tempsocks.prev, 569 struct svc_xprt, 570 xpt_list); 571 set_bit(XPT_CLOSE, &xprt->xpt_flags); 572 svc_xprt_get(xprt); 573 } 574 spin_unlock_bh(&serv->sv_lock); 575 576 if (xprt) { 577 svc_xprt_enqueue(xprt); 578 svc_xprt_put(xprt); 579 } 580 } 581 } 582 583 static int svc_alloc_arg(struct svc_rqst *rqstp) 584 { 585 struct svc_serv *serv = rqstp->rq_server; 586 struct xdr_buf *arg; 587 int pages; 588 int i; 589 590 /* now allocate needed pages. If we get a failure, sleep briefly */ 591 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; 592 WARN_ON_ONCE(pages >= RPCSVC_MAXPAGES); 593 if (pages >= RPCSVC_MAXPAGES) 594 /* use as many pages as possible */ 595 pages = RPCSVC_MAXPAGES - 1; 596 for (i = 0; i < pages ; i++) 597 while (rqstp->rq_pages[i] == NULL) { 598 struct page *p = alloc_page(GFP_KERNEL); 599 if (!p) { 600 set_current_state(TASK_INTERRUPTIBLE); 601 if (signalled() || kthread_should_stop()) { 602 set_current_state(TASK_RUNNING); 603 return -EINTR; 604 } 605 schedule_timeout(msecs_to_jiffies(500)); 606 } 607 rqstp->rq_pages[i] = p; 608 } 609 rqstp->rq_page_end = &rqstp->rq_pages[i]; 610 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ 611 612 /* Make arg->head point to first page and arg->pages point to rest */ 613 arg = &rqstp->rq_arg; 614 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 615 arg->head[0].iov_len = PAGE_SIZE; 616 arg->pages = rqstp->rq_pages + 1; 617 arg->page_base = 0; 618 /* save at least one page for response */ 619 arg->page_len = (pages-2)*PAGE_SIZE; 620 arg->len = (pages-1)*PAGE_SIZE; 621 arg->tail[0].iov_len = 0; 622 return 0; 623 } 624 625 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 626 { 627 struct svc_xprt *xprt; 628 struct svc_pool *pool = rqstp->rq_pool; 629 long time_left = 0; 630 631 /* Normally we will wait up to 5 seconds for any required 632 * cache information to be provided. 633 */ 634 rqstp->rq_chandle.thread_wait = 5*HZ; 635 636 spin_lock_bh(&pool->sp_lock); 637 xprt = svc_xprt_dequeue(pool); 638 if (xprt) { 639 rqstp->rq_xprt = xprt; 640 svc_xprt_get(xprt); 641 642 /* As there is a shortage of threads and this request 643 * had to be queued, don't allow the thread to wait so 644 * long for cache updates. 645 */ 646 rqstp->rq_chandle.thread_wait = 1*HZ; 647 pool->sp_task_pending = 0; 648 } else { 649 if (pool->sp_task_pending) { 650 pool->sp_task_pending = 0; 651 xprt = ERR_PTR(-EAGAIN); 652 goto out; 653 } 654 /* 655 * We have to be able to interrupt this wait 656 * to bring down the daemons ... 657 */ 658 set_current_state(TASK_INTERRUPTIBLE); 659 660 /* No data pending. Go to sleep */ 661 svc_thread_enqueue(pool, rqstp); 662 spin_unlock_bh(&pool->sp_lock); 663 664 if (!(signalled() || kthread_should_stop())) { 665 time_left = schedule_timeout(timeout); 666 __set_current_state(TASK_RUNNING); 667 668 try_to_freeze(); 669 670 xprt = rqstp->rq_xprt; 671 if (xprt != NULL) 672 return xprt; 673 } else 674 __set_current_state(TASK_RUNNING); 675 676 spin_lock_bh(&pool->sp_lock); 677 if (!time_left) 678 pool->sp_stats.threads_timedout++; 679 680 xprt = rqstp->rq_xprt; 681 if (!xprt) { 682 svc_thread_dequeue(pool, rqstp); 683 spin_unlock_bh(&pool->sp_lock); 684 dprintk("svc: server %p, no data yet\n", rqstp); 685 if (signalled() || kthread_should_stop()) 686 return ERR_PTR(-EINTR); 687 else 688 return ERR_PTR(-EAGAIN); 689 } 690 } 691 out: 692 spin_unlock_bh(&pool->sp_lock); 693 return xprt; 694 } 695 696 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 697 { 698 spin_lock_bh(&serv->sv_lock); 699 set_bit(XPT_TEMP, &newxpt->xpt_flags); 700 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 701 serv->sv_tmpcnt++; 702 if (serv->sv_temptimer.function == NULL) { 703 /* setup timer to age temp transports */ 704 setup_timer(&serv->sv_temptimer, svc_age_temp_xprts, 705 (unsigned long)serv); 706 mod_timer(&serv->sv_temptimer, 707 jiffies + svc_conn_age_period * HZ); 708 } 709 spin_unlock_bh(&serv->sv_lock); 710 svc_xprt_received(newxpt); 711 } 712 713 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 714 { 715 struct svc_serv *serv = rqstp->rq_server; 716 int len = 0; 717 718 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 719 dprintk("svc_recv: found XPT_CLOSE\n"); 720 svc_delete_xprt(xprt); 721 /* Leave XPT_BUSY set on the dead xprt: */ 722 return 0; 723 } 724 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 725 struct svc_xprt *newxpt; 726 /* 727 * We know this module_get will succeed because the 728 * listener holds a reference too 729 */ 730 __module_get(xprt->xpt_class->xcl_owner); 731 svc_check_conn_limits(xprt->xpt_server); 732 newxpt = xprt->xpt_ops->xpo_accept(xprt); 733 if (newxpt) 734 svc_add_new_temp_xprt(serv, newxpt); 735 else 736 module_put(xprt->xpt_class->xcl_owner); 737 } else { 738 /* XPT_DATA|XPT_DEFERRED case: */ 739 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 740 rqstp, rqstp->rq_pool->sp_id, xprt, 741 atomic_read(&xprt->xpt_ref.refcount)); 742 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 743 if (rqstp->rq_deferred) 744 len = svc_deferred_recv(rqstp); 745 else 746 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 747 dprintk("svc: got len=%d\n", len); 748 rqstp->rq_reserved = serv->sv_max_mesg; 749 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 750 } 751 /* clear XPT_BUSY: */ 752 svc_xprt_received(xprt); 753 return len; 754 } 755 756 /* 757 * Receive the next request on any transport. This code is carefully 758 * organised not to touch any cachelines in the shared svc_serv 759 * structure, only cachelines in the local svc_pool. 760 */ 761 int svc_recv(struct svc_rqst *rqstp, long timeout) 762 { 763 struct svc_xprt *xprt = NULL; 764 struct svc_serv *serv = rqstp->rq_server; 765 int len, err; 766 767 dprintk("svc: server %p waiting for data (to = %ld)\n", 768 rqstp, timeout); 769 770 if (rqstp->rq_xprt) 771 printk(KERN_ERR 772 "svc_recv: service %p, transport not NULL!\n", 773 rqstp); 774 775 err = svc_alloc_arg(rqstp); 776 if (err) 777 goto out; 778 779 try_to_freeze(); 780 cond_resched(); 781 err = -EINTR; 782 if (signalled() || kthread_should_stop()) 783 goto out; 784 785 xprt = svc_get_next_xprt(rqstp, timeout); 786 if (IS_ERR(xprt)) { 787 err = PTR_ERR(xprt); 788 goto out; 789 } 790 791 len = svc_handle_xprt(rqstp, xprt); 792 793 /* No data, incomplete (TCP) read, or accept() */ 794 err = -EAGAIN; 795 if (len <= 0) 796 goto out_release; 797 798 clear_bit(XPT_OLD, &xprt->xpt_flags); 799 800 rqstp->rq_secure = xprt->xpt_ops->xpo_secure_port(rqstp); 801 rqstp->rq_chandle.defer = svc_defer; 802 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 803 804 if (serv->sv_stats) 805 serv->sv_stats->netcnt++; 806 trace_svc_recv(rqstp, len); 807 return len; 808 out_release: 809 rqstp->rq_res.len = 0; 810 svc_xprt_release(rqstp); 811 out: 812 trace_svc_recv(rqstp, err); 813 return err; 814 } 815 EXPORT_SYMBOL_GPL(svc_recv); 816 817 /* 818 * Drop request 819 */ 820 void svc_drop(struct svc_rqst *rqstp) 821 { 822 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); 823 svc_xprt_release(rqstp); 824 } 825 EXPORT_SYMBOL_GPL(svc_drop); 826 827 /* 828 * Return reply to client. 829 */ 830 int svc_send(struct svc_rqst *rqstp) 831 { 832 struct svc_xprt *xprt; 833 int len = -EFAULT; 834 struct xdr_buf *xb; 835 836 xprt = rqstp->rq_xprt; 837 if (!xprt) 838 goto out; 839 840 /* release the receive skb before sending the reply */ 841 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); 842 843 /* calculate over-all length */ 844 xb = &rqstp->rq_res; 845 xb->len = xb->head[0].iov_len + 846 xb->page_len + 847 xb->tail[0].iov_len; 848 849 /* Grab mutex to serialize outgoing data. */ 850 mutex_lock(&xprt->xpt_mutex); 851 if (test_bit(XPT_DEAD, &xprt->xpt_flags) 852 || test_bit(XPT_CLOSE, &xprt->xpt_flags)) 853 len = -ENOTCONN; 854 else 855 len = xprt->xpt_ops->xpo_sendto(rqstp); 856 mutex_unlock(&xprt->xpt_mutex); 857 rpc_wake_up(&xprt->xpt_bc_pending); 858 svc_xprt_release(rqstp); 859 860 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 861 len = 0; 862 out: 863 trace_svc_send(rqstp, len); 864 return len; 865 } 866 867 /* 868 * Timer function to close old temporary transports, using 869 * a mark-and-sweep algorithm. 870 */ 871 static void svc_age_temp_xprts(unsigned long closure) 872 { 873 struct svc_serv *serv = (struct svc_serv *)closure; 874 struct svc_xprt *xprt; 875 struct list_head *le, *next; 876 877 dprintk("svc_age_temp_xprts\n"); 878 879 if (!spin_trylock_bh(&serv->sv_lock)) { 880 /* busy, try again 1 sec later */ 881 dprintk("svc_age_temp_xprts: busy\n"); 882 mod_timer(&serv->sv_temptimer, jiffies + HZ); 883 return; 884 } 885 886 list_for_each_safe(le, next, &serv->sv_tempsocks) { 887 xprt = list_entry(le, struct svc_xprt, xpt_list); 888 889 /* First time through, just mark it OLD. Second time 890 * through, close it. */ 891 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 892 continue; 893 if (atomic_read(&xprt->xpt_ref.refcount) > 1 || 894 test_bit(XPT_BUSY, &xprt->xpt_flags)) 895 continue; 896 list_del_init(le); 897 set_bit(XPT_CLOSE, &xprt->xpt_flags); 898 set_bit(XPT_DETACHED, &xprt->xpt_flags); 899 dprintk("queuing xprt %p for closing\n", xprt); 900 901 /* a thread will dequeue and close it soon */ 902 svc_xprt_enqueue(xprt); 903 } 904 spin_unlock_bh(&serv->sv_lock); 905 906 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 907 } 908 909 static void call_xpt_users(struct svc_xprt *xprt) 910 { 911 struct svc_xpt_user *u; 912 913 spin_lock(&xprt->xpt_lock); 914 while (!list_empty(&xprt->xpt_users)) { 915 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 916 list_del(&u->list); 917 u->callback(u); 918 } 919 spin_unlock(&xprt->xpt_lock); 920 } 921 922 /* 923 * Remove a dead transport 924 */ 925 static void svc_delete_xprt(struct svc_xprt *xprt) 926 { 927 struct svc_serv *serv = xprt->xpt_server; 928 struct svc_deferred_req *dr; 929 930 /* Only do this once */ 931 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 932 BUG(); 933 934 dprintk("svc: svc_delete_xprt(%p)\n", xprt); 935 xprt->xpt_ops->xpo_detach(xprt); 936 937 spin_lock_bh(&serv->sv_lock); 938 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) 939 list_del_init(&xprt->xpt_list); 940 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 941 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 942 serv->sv_tmpcnt--; 943 spin_unlock_bh(&serv->sv_lock); 944 945 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 946 kfree(dr); 947 948 call_xpt_users(xprt); 949 svc_xprt_put(xprt); 950 } 951 952 void svc_close_xprt(struct svc_xprt *xprt) 953 { 954 set_bit(XPT_CLOSE, &xprt->xpt_flags); 955 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 956 /* someone else will have to effect the close */ 957 return; 958 /* 959 * We expect svc_close_xprt() to work even when no threads are 960 * running (e.g., while configuring the server before starting 961 * any threads), so if the transport isn't busy, we delete 962 * it ourself: 963 */ 964 svc_delete_xprt(xprt); 965 } 966 EXPORT_SYMBOL_GPL(svc_close_xprt); 967 968 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 969 { 970 struct svc_xprt *xprt; 971 int ret = 0; 972 973 spin_lock(&serv->sv_lock); 974 list_for_each_entry(xprt, xprt_list, xpt_list) { 975 if (xprt->xpt_net != net) 976 continue; 977 ret++; 978 set_bit(XPT_CLOSE, &xprt->xpt_flags); 979 svc_xprt_enqueue(xprt); 980 } 981 spin_unlock(&serv->sv_lock); 982 return ret; 983 } 984 985 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 986 { 987 struct svc_pool *pool; 988 struct svc_xprt *xprt; 989 struct svc_xprt *tmp; 990 int i; 991 992 for (i = 0; i < serv->sv_nrpools; i++) { 993 pool = &serv->sv_pools[i]; 994 995 spin_lock_bh(&pool->sp_lock); 996 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 997 if (xprt->xpt_net != net) 998 continue; 999 list_del_init(&xprt->xpt_ready); 1000 spin_unlock_bh(&pool->sp_lock); 1001 return xprt; 1002 } 1003 spin_unlock_bh(&pool->sp_lock); 1004 } 1005 return NULL; 1006 } 1007 1008 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1009 { 1010 struct svc_xprt *xprt; 1011 1012 while ((xprt = svc_dequeue_net(serv, net))) { 1013 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1014 svc_delete_xprt(xprt); 1015 } 1016 } 1017 1018 /* 1019 * Server threads may still be running (especially in the case where the 1020 * service is still running in other network namespaces). 1021 * 1022 * So we shut down sockets the same way we would on a running server, by 1023 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1024 * the close. In the case there are no such other threads, 1025 * threads running, svc_clean_up_xprts() does a simple version of a 1026 * server's main event loop, and in the case where there are other 1027 * threads, we may need to wait a little while and then check again to 1028 * see if they're done. 1029 */ 1030 void svc_close_net(struct svc_serv *serv, struct net *net) 1031 { 1032 int delay = 0; 1033 1034 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1035 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1036 1037 svc_clean_up_xprts(serv, net); 1038 msleep(delay++); 1039 } 1040 } 1041 1042 /* 1043 * Handle defer and revisit of requests 1044 */ 1045 1046 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1047 { 1048 struct svc_deferred_req *dr = 1049 container_of(dreq, struct svc_deferred_req, handle); 1050 struct svc_xprt *xprt = dr->xprt; 1051 1052 spin_lock(&xprt->xpt_lock); 1053 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1054 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1055 spin_unlock(&xprt->xpt_lock); 1056 dprintk("revisit canceled\n"); 1057 svc_xprt_put(xprt); 1058 kfree(dr); 1059 return; 1060 } 1061 dprintk("revisit queued\n"); 1062 dr->xprt = NULL; 1063 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1064 spin_unlock(&xprt->xpt_lock); 1065 svc_xprt_enqueue(xprt); 1066 svc_xprt_put(xprt); 1067 } 1068 1069 /* 1070 * Save the request off for later processing. The request buffer looks 1071 * like this: 1072 * 1073 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1074 * 1075 * This code can only handle requests that consist of an xprt-header 1076 * and rpc-header. 1077 */ 1078 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1079 { 1080 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1081 struct svc_deferred_req *dr; 1082 1083 if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral) 1084 return NULL; /* if more than a page, give up FIXME */ 1085 if (rqstp->rq_deferred) { 1086 dr = rqstp->rq_deferred; 1087 rqstp->rq_deferred = NULL; 1088 } else { 1089 size_t skip; 1090 size_t size; 1091 /* FIXME maybe discard if size too large */ 1092 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1093 dr = kmalloc(size, GFP_KERNEL); 1094 if (dr == NULL) 1095 return NULL; 1096 1097 dr->handle.owner = rqstp->rq_server; 1098 dr->prot = rqstp->rq_prot; 1099 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1100 dr->addrlen = rqstp->rq_addrlen; 1101 dr->daddr = rqstp->rq_daddr; 1102 dr->argslen = rqstp->rq_arg.len >> 2; 1103 dr->xprt_hlen = rqstp->rq_xprt_hlen; 1104 1105 /* back up head to the start of the buffer and copy */ 1106 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1107 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1108 dr->argslen << 2); 1109 } 1110 svc_xprt_get(rqstp->rq_xprt); 1111 dr->xprt = rqstp->rq_xprt; 1112 rqstp->rq_dropme = true; 1113 1114 dr->handle.revisit = svc_revisit; 1115 return &dr->handle; 1116 } 1117 1118 /* 1119 * recv data from a deferred request into an active one 1120 */ 1121 static int svc_deferred_recv(struct svc_rqst *rqstp) 1122 { 1123 struct svc_deferred_req *dr = rqstp->rq_deferred; 1124 1125 /* setup iov_base past transport header */ 1126 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); 1127 /* The iov_len does not include the transport header bytes */ 1128 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; 1129 rqstp->rq_arg.page_len = 0; 1130 /* The rq_arg.len includes the transport header bytes */ 1131 rqstp->rq_arg.len = dr->argslen<<2; 1132 rqstp->rq_prot = dr->prot; 1133 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1134 rqstp->rq_addrlen = dr->addrlen; 1135 /* Save off transport header len in case we get deferred again */ 1136 rqstp->rq_xprt_hlen = dr->xprt_hlen; 1137 rqstp->rq_daddr = dr->daddr; 1138 rqstp->rq_respages = rqstp->rq_pages; 1139 return (dr->argslen<<2) - dr->xprt_hlen; 1140 } 1141 1142 1143 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1144 { 1145 struct svc_deferred_req *dr = NULL; 1146 1147 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1148 return NULL; 1149 spin_lock(&xprt->xpt_lock); 1150 if (!list_empty(&xprt->xpt_deferred)) { 1151 dr = list_entry(xprt->xpt_deferred.next, 1152 struct svc_deferred_req, 1153 handle.recent); 1154 list_del_init(&dr->handle.recent); 1155 } else 1156 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1157 spin_unlock(&xprt->xpt_lock); 1158 return dr; 1159 } 1160 1161 /** 1162 * svc_find_xprt - find an RPC transport instance 1163 * @serv: pointer to svc_serv to search 1164 * @xcl_name: C string containing transport's class name 1165 * @net: owner net pointer 1166 * @af: Address family of transport's local address 1167 * @port: transport's IP port number 1168 * 1169 * Return the transport instance pointer for the endpoint accepting 1170 * connections/peer traffic from the specified transport class, 1171 * address family and port. 1172 * 1173 * Specifying 0 for the address family or port is effectively a 1174 * wild-card, and will result in matching the first transport in the 1175 * service's list that has a matching class name. 1176 */ 1177 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1178 struct net *net, const sa_family_t af, 1179 const unsigned short port) 1180 { 1181 struct svc_xprt *xprt; 1182 struct svc_xprt *found = NULL; 1183 1184 /* Sanity check the args */ 1185 if (serv == NULL || xcl_name == NULL) 1186 return found; 1187 1188 spin_lock_bh(&serv->sv_lock); 1189 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1190 if (xprt->xpt_net != net) 1191 continue; 1192 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1193 continue; 1194 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1195 continue; 1196 if (port != 0 && port != svc_xprt_local_port(xprt)) 1197 continue; 1198 found = xprt; 1199 svc_xprt_get(xprt); 1200 break; 1201 } 1202 spin_unlock_bh(&serv->sv_lock); 1203 return found; 1204 } 1205 EXPORT_SYMBOL_GPL(svc_find_xprt); 1206 1207 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1208 char *pos, int remaining) 1209 { 1210 int len; 1211 1212 len = snprintf(pos, remaining, "%s %u\n", 1213 xprt->xpt_class->xcl_name, 1214 svc_xprt_local_port(xprt)); 1215 if (len >= remaining) 1216 return -ENAMETOOLONG; 1217 return len; 1218 } 1219 1220 /** 1221 * svc_xprt_names - format a buffer with a list of transport names 1222 * @serv: pointer to an RPC service 1223 * @buf: pointer to a buffer to be filled in 1224 * @buflen: length of buffer to be filled in 1225 * 1226 * Fills in @buf with a string containing a list of transport names, 1227 * each name terminated with '\n'. 1228 * 1229 * Returns positive length of the filled-in string on success; otherwise 1230 * a negative errno value is returned if an error occurs. 1231 */ 1232 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1233 { 1234 struct svc_xprt *xprt; 1235 int len, totlen; 1236 char *pos; 1237 1238 /* Sanity check args */ 1239 if (!serv) 1240 return 0; 1241 1242 spin_lock_bh(&serv->sv_lock); 1243 1244 pos = buf; 1245 totlen = 0; 1246 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1247 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1248 if (len < 0) { 1249 *buf = '\0'; 1250 totlen = len; 1251 } 1252 if (len <= 0) 1253 break; 1254 1255 pos += len; 1256 totlen += len; 1257 } 1258 1259 spin_unlock_bh(&serv->sv_lock); 1260 return totlen; 1261 } 1262 EXPORT_SYMBOL_GPL(svc_xprt_names); 1263 1264 1265 /*----------------------------------------------------------------------------*/ 1266 1267 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1268 { 1269 unsigned int pidx = (unsigned int)*pos; 1270 struct svc_serv *serv = m->private; 1271 1272 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1273 1274 if (!pidx) 1275 return SEQ_START_TOKEN; 1276 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1277 } 1278 1279 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1280 { 1281 struct svc_pool *pool = p; 1282 struct svc_serv *serv = m->private; 1283 1284 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1285 1286 if (p == SEQ_START_TOKEN) { 1287 pool = &serv->sv_pools[0]; 1288 } else { 1289 unsigned int pidx = (pool - &serv->sv_pools[0]); 1290 if (pidx < serv->sv_nrpools-1) 1291 pool = &serv->sv_pools[pidx+1]; 1292 else 1293 pool = NULL; 1294 } 1295 ++*pos; 1296 return pool; 1297 } 1298 1299 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1300 { 1301 } 1302 1303 static int svc_pool_stats_show(struct seq_file *m, void *p) 1304 { 1305 struct svc_pool *pool = p; 1306 1307 if (p == SEQ_START_TOKEN) { 1308 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1309 return 0; 1310 } 1311 1312 seq_printf(m, "%u %lu %lu %lu %lu\n", 1313 pool->sp_id, 1314 pool->sp_stats.packets, 1315 pool->sp_stats.sockets_queued, 1316 pool->sp_stats.threads_woken, 1317 pool->sp_stats.threads_timedout); 1318 1319 return 0; 1320 } 1321 1322 static const struct seq_operations svc_pool_stats_seq_ops = { 1323 .start = svc_pool_stats_start, 1324 .next = svc_pool_stats_next, 1325 .stop = svc_pool_stats_stop, 1326 .show = svc_pool_stats_show, 1327 }; 1328 1329 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1330 { 1331 int err; 1332 1333 err = seq_open(file, &svc_pool_stats_seq_ops); 1334 if (!err) 1335 ((struct seq_file *) file->private_data)->private = serv; 1336 return err; 1337 } 1338 EXPORT_SYMBOL(svc_pool_stats_open); 1339 1340 /*----------------------------------------------------------------------------*/ 1341