1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/net/sunrpc/svc_xprt.c 4 * 5 * Author: Tom Tucker <tom@opengridcomputing.com> 6 */ 7 8 #include <linux/sched.h> 9 #include <linux/errno.h> 10 #include <linux/freezer.h> 11 #include <linux/kthread.h> 12 #include <linux/slab.h> 13 #include <net/sock.h> 14 #include <linux/sunrpc/addr.h> 15 #include <linux/sunrpc/stats.h> 16 #include <linux/sunrpc/svc_xprt.h> 17 #include <linux/sunrpc/svcsock.h> 18 #include <linux/sunrpc/xprt.h> 19 #include <linux/module.h> 20 #include <linux/netdevice.h> 21 #include <trace/events/sunrpc.h> 22 23 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 24 25 static unsigned int svc_rpc_per_connection_limit __read_mostly; 26 module_param(svc_rpc_per_connection_limit, uint, 0644); 27 28 29 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); 30 static int svc_deferred_recv(struct svc_rqst *rqstp); 31 static struct cache_deferred_req *svc_defer(struct cache_req *req); 32 static void svc_age_temp_xprts(struct timer_list *t); 33 static void svc_delete_xprt(struct svc_xprt *xprt); 34 35 /* apparently the "standard" is that clients close 36 * idle connections after 5 minutes, servers after 37 * 6 minutes 38 * http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf 39 */ 40 static int svc_conn_age_period = 6*60; 41 42 /* List of registered transport classes */ 43 static DEFINE_SPINLOCK(svc_xprt_class_lock); 44 static LIST_HEAD(svc_xprt_class_list); 45 46 /* SMP locking strategy: 47 * 48 * svc_pool->sp_lock protects most of the fields of that pool. 49 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. 50 * when both need to be taken (rare), svc_serv->sv_lock is first. 51 * The "service mutex" protects svc_serv->sv_nrthread. 52 * svc_sock->sk_lock protects the svc_sock->sk_deferred list 53 * and the ->sk_info_authunix cache. 54 * 55 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being 56 * enqueued multiply. During normal transport processing this bit 57 * is set by svc_xprt_enqueue and cleared by svc_xprt_received. 58 * Providers should not manipulate this bit directly. 59 * 60 * Some flags can be set to certain values at any time 61 * providing that certain rules are followed: 62 * 63 * XPT_CONN, XPT_DATA: 64 * - Can be set or cleared at any time. 65 * - After a set, svc_xprt_enqueue must be called to enqueue 66 * the transport for processing. 67 * - After a clear, the transport must be read/accepted. 68 * If this succeeds, it must be set again. 69 * XPT_CLOSE: 70 * - Can set at any time. It is never cleared. 71 * XPT_DEAD: 72 * - Can only be set while XPT_BUSY is held which ensures 73 * that no other thread will be using the transport or will 74 * try to set XPT_DEAD. 75 */ 76 int svc_reg_xprt_class(struct svc_xprt_class *xcl) 77 { 78 struct svc_xprt_class *cl; 79 int res = -EEXIST; 80 81 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); 82 83 INIT_LIST_HEAD(&xcl->xcl_list); 84 spin_lock(&svc_xprt_class_lock); 85 /* Make sure there isn't already a class with the same name */ 86 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { 87 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) 88 goto out; 89 } 90 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); 91 res = 0; 92 out: 93 spin_unlock(&svc_xprt_class_lock); 94 return res; 95 } 96 EXPORT_SYMBOL_GPL(svc_reg_xprt_class); 97 98 void svc_unreg_xprt_class(struct svc_xprt_class *xcl) 99 { 100 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); 101 spin_lock(&svc_xprt_class_lock); 102 list_del_init(&xcl->xcl_list); 103 spin_unlock(&svc_xprt_class_lock); 104 } 105 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); 106 107 /** 108 * svc_print_xprts - Format the transport list for printing 109 * @buf: target buffer for formatted address 110 * @maxlen: length of target buffer 111 * 112 * Fills in @buf with a string containing a list of transport names, each name 113 * terminated with '\n'. If the buffer is too small, some entries may be 114 * missing, but it is guaranteed that all lines in the output buffer are 115 * complete. 116 * 117 * Returns positive length of the filled-in string. 118 */ 119 int svc_print_xprts(char *buf, int maxlen) 120 { 121 struct svc_xprt_class *xcl; 122 char tmpstr[80]; 123 int len = 0; 124 buf[0] = '\0'; 125 126 spin_lock(&svc_xprt_class_lock); 127 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 128 int slen; 129 130 slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", 131 xcl->xcl_name, xcl->xcl_max_payload); 132 if (slen >= sizeof(tmpstr) || len + slen >= maxlen) 133 break; 134 len += slen; 135 strcat(buf, tmpstr); 136 } 137 spin_unlock(&svc_xprt_class_lock); 138 139 return len; 140 } 141 142 static void svc_xprt_free(struct kref *kref) 143 { 144 struct svc_xprt *xprt = 145 container_of(kref, struct svc_xprt, xpt_ref); 146 struct module *owner = xprt->xpt_class->xcl_owner; 147 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 148 svcauth_unix_info_release(xprt); 149 put_cred(xprt->xpt_cred); 150 put_net(xprt->xpt_net); 151 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 152 if (xprt->xpt_bc_xprt) 153 xprt_put(xprt->xpt_bc_xprt); 154 if (xprt->xpt_bc_xps) 155 xprt_switch_put(xprt->xpt_bc_xps); 156 trace_svc_xprt_free(xprt); 157 xprt->xpt_ops->xpo_free(xprt); 158 module_put(owner); 159 } 160 161 void svc_xprt_put(struct svc_xprt *xprt) 162 { 163 kref_put(&xprt->xpt_ref, svc_xprt_free); 164 } 165 EXPORT_SYMBOL_GPL(svc_xprt_put); 166 167 /* 168 * Called by transport drivers to initialize the transport independent 169 * portion of the transport instance. 170 */ 171 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 172 struct svc_xprt *xprt, struct svc_serv *serv) 173 { 174 memset(xprt, 0, sizeof(*xprt)); 175 xprt->xpt_class = xcl; 176 xprt->xpt_ops = xcl->xcl_ops; 177 kref_init(&xprt->xpt_ref); 178 xprt->xpt_server = serv; 179 INIT_LIST_HEAD(&xprt->xpt_list); 180 INIT_LIST_HEAD(&xprt->xpt_ready); 181 INIT_LIST_HEAD(&xprt->xpt_deferred); 182 INIT_LIST_HEAD(&xprt->xpt_users); 183 mutex_init(&xprt->xpt_mutex); 184 spin_lock_init(&xprt->xpt_lock); 185 set_bit(XPT_BUSY, &xprt->xpt_flags); 186 xprt->xpt_net = get_net(net); 187 strcpy(xprt->xpt_remotebuf, "uninitialized"); 188 } 189 EXPORT_SYMBOL_GPL(svc_xprt_init); 190 191 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 192 struct svc_serv *serv, 193 struct net *net, 194 const int family, 195 const unsigned short port, 196 int flags) 197 { 198 struct sockaddr_in sin = { 199 .sin_family = AF_INET, 200 .sin_addr.s_addr = htonl(INADDR_ANY), 201 .sin_port = htons(port), 202 }; 203 #if IS_ENABLED(CONFIG_IPV6) 204 struct sockaddr_in6 sin6 = { 205 .sin6_family = AF_INET6, 206 .sin6_addr = IN6ADDR_ANY_INIT, 207 .sin6_port = htons(port), 208 }; 209 #endif 210 struct svc_xprt *xprt; 211 struct sockaddr *sap; 212 size_t len; 213 214 switch (family) { 215 case PF_INET: 216 sap = (struct sockaddr *)&sin; 217 len = sizeof(sin); 218 break; 219 #if IS_ENABLED(CONFIG_IPV6) 220 case PF_INET6: 221 sap = (struct sockaddr *)&sin6; 222 len = sizeof(sin6); 223 break; 224 #endif 225 default: 226 return ERR_PTR(-EAFNOSUPPORT); 227 } 228 229 xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 230 if (IS_ERR(xprt)) 231 trace_svc_xprt_create_err(serv->sv_program->pg_name, 232 xcl->xcl_name, sap, xprt); 233 return xprt; 234 } 235 236 /* 237 * svc_xprt_received conditionally queues the transport for processing 238 * by another thread. The caller must hold the XPT_BUSY bit and must 239 * not thereafter touch transport data. 240 * 241 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 242 * insufficient) data. 243 */ 244 static void svc_xprt_received(struct svc_xprt *xprt) 245 { 246 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 247 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 248 return; 249 } 250 251 /* As soon as we clear busy, the xprt could be closed and 252 * 'put', so we need a reference to call svc_enqueue_xprt with: 253 */ 254 svc_xprt_get(xprt); 255 smp_mb__before_atomic(); 256 clear_bit(XPT_BUSY, &xprt->xpt_flags); 257 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 258 svc_xprt_put(xprt); 259 } 260 261 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 262 { 263 clear_bit(XPT_TEMP, &new->xpt_flags); 264 spin_lock_bh(&serv->sv_lock); 265 list_add(&new->xpt_list, &serv->sv_permsocks); 266 spin_unlock_bh(&serv->sv_lock); 267 svc_xprt_received(new); 268 } 269 270 static int _svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 271 struct net *net, const int family, 272 const unsigned short port, int flags, 273 const struct cred *cred) 274 { 275 struct svc_xprt_class *xcl; 276 277 spin_lock(&svc_xprt_class_lock); 278 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 279 struct svc_xprt *newxprt; 280 unsigned short newport; 281 282 if (strcmp(xprt_name, xcl->xcl_name)) 283 continue; 284 285 if (!try_module_get(xcl->xcl_owner)) 286 goto err; 287 288 spin_unlock(&svc_xprt_class_lock); 289 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 290 if (IS_ERR(newxprt)) { 291 module_put(xcl->xcl_owner); 292 return PTR_ERR(newxprt); 293 } 294 newxprt->xpt_cred = get_cred(cred); 295 svc_add_new_perm_xprt(serv, newxprt); 296 newport = svc_xprt_local_port(newxprt); 297 return newport; 298 } 299 err: 300 spin_unlock(&svc_xprt_class_lock); 301 /* This errno is exposed to user space. Provide a reasonable 302 * perror msg for a bad transport. */ 303 return -EPROTONOSUPPORT; 304 } 305 306 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 307 struct net *net, const int family, 308 const unsigned short port, int flags, 309 const struct cred *cred) 310 { 311 int err; 312 313 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); 314 if (err == -EPROTONOSUPPORT) { 315 request_module("svc%s", xprt_name); 316 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); 317 } 318 return err; 319 } 320 EXPORT_SYMBOL_GPL(svc_create_xprt); 321 322 /* 323 * Copy the local and remote xprt addresses to the rqstp structure 324 */ 325 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 326 { 327 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 328 rqstp->rq_addrlen = xprt->xpt_remotelen; 329 330 /* 331 * Destination address in request is needed for binding the 332 * source address in RPC replies/callbacks later. 333 */ 334 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 335 rqstp->rq_daddrlen = xprt->xpt_locallen; 336 } 337 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 338 339 /** 340 * svc_print_addr - Format rq_addr field for printing 341 * @rqstp: svc_rqst struct containing address to print 342 * @buf: target buffer for formatted address 343 * @len: length of target buffer 344 * 345 */ 346 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 347 { 348 return __svc_print_addr(svc_addr(rqstp), buf, len); 349 } 350 EXPORT_SYMBOL_GPL(svc_print_addr); 351 352 static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) 353 { 354 unsigned int limit = svc_rpc_per_connection_limit; 355 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); 356 357 return limit == 0 || (nrqsts >= 0 && nrqsts < limit); 358 } 359 360 static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) 361 { 362 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { 363 if (!svc_xprt_slots_in_range(xprt)) 364 return false; 365 atomic_inc(&xprt->xpt_nr_rqsts); 366 set_bit(RQ_DATA, &rqstp->rq_flags); 367 } 368 return true; 369 } 370 371 static void svc_xprt_release_slot(struct svc_rqst *rqstp) 372 { 373 struct svc_xprt *xprt = rqstp->rq_xprt; 374 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { 375 atomic_dec(&xprt->xpt_nr_rqsts); 376 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 377 svc_xprt_enqueue(xprt); 378 } 379 } 380 381 static bool svc_xprt_ready(struct svc_xprt *xprt) 382 { 383 unsigned long xpt_flags; 384 385 /* 386 * If another cpu has recently updated xpt_flags, 387 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to 388 * know about it; otherwise it's possible that both that cpu and 389 * this one could call svc_xprt_enqueue() without either 390 * svc_xprt_enqueue() recognizing that the conditions below 391 * are satisfied, and we could stall indefinitely: 392 */ 393 smp_rmb(); 394 xpt_flags = READ_ONCE(xprt->xpt_flags); 395 396 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) 397 return true; 398 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { 399 if (xprt->xpt_ops->xpo_has_wspace(xprt) && 400 svc_xprt_slots_in_range(xprt)) 401 return true; 402 trace_svc_xprt_no_write_space(xprt); 403 return false; 404 } 405 return false; 406 } 407 408 void svc_xprt_do_enqueue(struct svc_xprt *xprt) 409 { 410 struct svc_pool *pool; 411 struct svc_rqst *rqstp = NULL; 412 int cpu; 413 414 if (!svc_xprt_ready(xprt)) 415 return; 416 417 /* Mark transport as busy. It will remain in this state until 418 * the provider calls svc_xprt_received. We update XPT_BUSY 419 * atomically because it also guards against trying to enqueue 420 * the transport twice. 421 */ 422 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 423 return; 424 425 cpu = get_cpu(); 426 pool = svc_pool_for_cpu(xprt->xpt_server, cpu); 427 428 atomic_long_inc(&pool->sp_stats.packets); 429 430 spin_lock_bh(&pool->sp_lock); 431 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 432 pool->sp_stats.sockets_queued++; 433 spin_unlock_bh(&pool->sp_lock); 434 435 /* find a thread for this xprt */ 436 rcu_read_lock(); 437 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 438 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) 439 continue; 440 atomic_long_inc(&pool->sp_stats.threads_woken); 441 rqstp->rq_qtime = ktime_get(); 442 wake_up_process(rqstp->rq_task); 443 goto out_unlock; 444 } 445 set_bit(SP_CONGESTED, &pool->sp_flags); 446 rqstp = NULL; 447 out_unlock: 448 rcu_read_unlock(); 449 put_cpu(); 450 trace_svc_xprt_do_enqueue(xprt, rqstp); 451 } 452 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); 453 454 /* 455 * Queue up a transport with data pending. If there are idle nfsd 456 * processes, wake 'em up. 457 * 458 */ 459 void svc_xprt_enqueue(struct svc_xprt *xprt) 460 { 461 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) 462 return; 463 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 464 } 465 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 466 467 /* 468 * Dequeue the first transport, if there is one. 469 */ 470 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 471 { 472 struct svc_xprt *xprt = NULL; 473 474 if (list_empty(&pool->sp_sockets)) 475 goto out; 476 477 spin_lock_bh(&pool->sp_lock); 478 if (likely(!list_empty(&pool->sp_sockets))) { 479 xprt = list_first_entry(&pool->sp_sockets, 480 struct svc_xprt, xpt_ready); 481 list_del_init(&xprt->xpt_ready); 482 svc_xprt_get(xprt); 483 } 484 spin_unlock_bh(&pool->sp_lock); 485 out: 486 return xprt; 487 } 488 489 /** 490 * svc_reserve - change the space reserved for the reply to a request. 491 * @rqstp: The request in question 492 * @space: new max space to reserve 493 * 494 * Each request reserves some space on the output queue of the transport 495 * to make sure the reply fits. This function reduces that reserved 496 * space to be the amount of space used already, plus @space. 497 * 498 */ 499 void svc_reserve(struct svc_rqst *rqstp, int space) 500 { 501 struct svc_xprt *xprt = rqstp->rq_xprt; 502 503 space += rqstp->rq_res.head[0].iov_len; 504 505 if (xprt && space < rqstp->rq_reserved) { 506 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 507 rqstp->rq_reserved = space; 508 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 509 svc_xprt_enqueue(xprt); 510 } 511 } 512 EXPORT_SYMBOL_GPL(svc_reserve); 513 514 static void svc_xprt_release(struct svc_rqst *rqstp) 515 { 516 struct svc_xprt *xprt = rqstp->rq_xprt; 517 518 xprt->xpt_ops->xpo_release_rqst(rqstp); 519 520 kfree(rqstp->rq_deferred); 521 rqstp->rq_deferred = NULL; 522 523 svc_free_res_pages(rqstp); 524 rqstp->rq_res.page_len = 0; 525 rqstp->rq_res.page_base = 0; 526 527 /* Reset response buffer and release 528 * the reservation. 529 * But first, check that enough space was reserved 530 * for the reply, otherwise we have a bug! 531 */ 532 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 533 printk(KERN_ERR "RPC request reserved %d but used %d\n", 534 rqstp->rq_reserved, 535 rqstp->rq_res.len); 536 537 rqstp->rq_res.head[0].iov_len = 0; 538 svc_reserve(rqstp, 0); 539 svc_xprt_release_slot(rqstp); 540 rqstp->rq_xprt = NULL; 541 svc_xprt_put(xprt); 542 } 543 544 /* 545 * Some svc_serv's will have occasional work to do, even when a xprt is not 546 * waiting to be serviced. This function is there to "kick" a task in one of 547 * those services so that it can wake up and do that work. Note that we only 548 * bother with pool 0 as we don't need to wake up more than one thread for 549 * this purpose. 550 */ 551 void svc_wake_up(struct svc_serv *serv) 552 { 553 struct svc_rqst *rqstp; 554 struct svc_pool *pool; 555 556 pool = &serv->sv_pools[0]; 557 558 rcu_read_lock(); 559 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 560 /* skip any that aren't queued */ 561 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 562 continue; 563 rcu_read_unlock(); 564 wake_up_process(rqstp->rq_task); 565 trace_svc_wake_up(rqstp->rq_task->pid); 566 return; 567 } 568 rcu_read_unlock(); 569 570 /* No free entries available */ 571 set_bit(SP_TASK_PENDING, &pool->sp_flags); 572 smp_wmb(); 573 trace_svc_wake_up(0); 574 } 575 EXPORT_SYMBOL_GPL(svc_wake_up); 576 577 int svc_port_is_privileged(struct sockaddr *sin) 578 { 579 switch (sin->sa_family) { 580 case AF_INET: 581 return ntohs(((struct sockaddr_in *)sin)->sin_port) 582 < PROT_SOCK; 583 case AF_INET6: 584 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 585 < PROT_SOCK; 586 default: 587 return 0; 588 } 589 } 590 591 /* 592 * Make sure that we don't have too many active connections. If we have, 593 * something must be dropped. It's not clear what will happen if we allow 594 * "too many" connections, but when dealing with network-facing software, 595 * we have to code defensively. Here we do that by imposing hard limits. 596 * 597 * There's no point in trying to do random drop here for DoS 598 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 599 * attacker can easily beat that. 600 * 601 * The only somewhat efficient mechanism would be if drop old 602 * connections from the same IP first. But right now we don't even 603 * record the client IP in svc_sock. 604 * 605 * single-threaded services that expect a lot of clients will probably 606 * need to set sv_maxconn to override the default value which is based 607 * on the number of threads 608 */ 609 static void svc_check_conn_limits(struct svc_serv *serv) 610 { 611 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 612 (serv->sv_nrthreads+3) * 20; 613 614 if (serv->sv_tmpcnt > limit) { 615 struct svc_xprt *xprt = NULL; 616 spin_lock_bh(&serv->sv_lock); 617 if (!list_empty(&serv->sv_tempsocks)) { 618 /* Try to help the admin */ 619 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 620 serv->sv_name, serv->sv_maxconn ? 621 "max number of connections" : 622 "number of threads"); 623 /* 624 * Always select the oldest connection. It's not fair, 625 * but so is life 626 */ 627 xprt = list_entry(serv->sv_tempsocks.prev, 628 struct svc_xprt, 629 xpt_list); 630 set_bit(XPT_CLOSE, &xprt->xpt_flags); 631 svc_xprt_get(xprt); 632 } 633 spin_unlock_bh(&serv->sv_lock); 634 635 if (xprt) { 636 svc_xprt_enqueue(xprt); 637 svc_xprt_put(xprt); 638 } 639 } 640 } 641 642 static int svc_alloc_arg(struct svc_rqst *rqstp) 643 { 644 struct svc_serv *serv = rqstp->rq_server; 645 struct xdr_buf *arg; 646 int pages; 647 int i; 648 649 /* now allocate needed pages. If we get a failure, sleep briefly */ 650 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 651 if (pages > RPCSVC_MAXPAGES) { 652 pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n", 653 pages, RPCSVC_MAXPAGES); 654 /* use as many pages as possible */ 655 pages = RPCSVC_MAXPAGES; 656 } 657 for (i = 0; i < pages ; i++) 658 while (rqstp->rq_pages[i] == NULL) { 659 struct page *p = alloc_page(GFP_KERNEL); 660 if (!p) { 661 set_current_state(TASK_INTERRUPTIBLE); 662 if (signalled() || kthread_should_stop()) { 663 set_current_state(TASK_RUNNING); 664 return -EINTR; 665 } 666 schedule_timeout(msecs_to_jiffies(500)); 667 } 668 rqstp->rq_pages[i] = p; 669 } 670 rqstp->rq_page_end = &rqstp->rq_pages[i]; 671 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ 672 673 /* Make arg->head point to first page and arg->pages point to rest */ 674 arg = &rqstp->rq_arg; 675 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 676 arg->head[0].iov_len = PAGE_SIZE; 677 arg->pages = rqstp->rq_pages + 1; 678 arg->page_base = 0; 679 /* save at least one page for response */ 680 arg->page_len = (pages-2)*PAGE_SIZE; 681 arg->len = (pages-1)*PAGE_SIZE; 682 arg->tail[0].iov_len = 0; 683 return 0; 684 } 685 686 static bool 687 rqst_should_sleep(struct svc_rqst *rqstp) 688 { 689 struct svc_pool *pool = rqstp->rq_pool; 690 691 /* did someone call svc_wake_up? */ 692 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 693 return false; 694 695 /* was a socket queued? */ 696 if (!list_empty(&pool->sp_sockets)) 697 return false; 698 699 /* are we shutting down? */ 700 if (signalled() || kthread_should_stop()) 701 return false; 702 703 /* are we freezing? */ 704 if (freezing(current)) 705 return false; 706 707 return true; 708 } 709 710 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 711 { 712 struct svc_pool *pool = rqstp->rq_pool; 713 long time_left = 0; 714 715 /* rq_xprt should be clear on entry */ 716 WARN_ON_ONCE(rqstp->rq_xprt); 717 718 rqstp->rq_xprt = svc_xprt_dequeue(pool); 719 if (rqstp->rq_xprt) 720 goto out_found; 721 722 /* 723 * We have to be able to interrupt this wait 724 * to bring down the daemons ... 725 */ 726 set_current_state(TASK_INTERRUPTIBLE); 727 smp_mb__before_atomic(); 728 clear_bit(SP_CONGESTED, &pool->sp_flags); 729 clear_bit(RQ_BUSY, &rqstp->rq_flags); 730 smp_mb__after_atomic(); 731 732 if (likely(rqst_should_sleep(rqstp))) 733 time_left = schedule_timeout(timeout); 734 else 735 __set_current_state(TASK_RUNNING); 736 737 try_to_freeze(); 738 739 set_bit(RQ_BUSY, &rqstp->rq_flags); 740 smp_mb__after_atomic(); 741 rqstp->rq_xprt = svc_xprt_dequeue(pool); 742 if (rqstp->rq_xprt) 743 goto out_found; 744 745 if (!time_left) 746 atomic_long_inc(&pool->sp_stats.threads_timedout); 747 748 if (signalled() || kthread_should_stop()) 749 return ERR_PTR(-EINTR); 750 return ERR_PTR(-EAGAIN); 751 out_found: 752 /* Normally we will wait up to 5 seconds for any required 753 * cache information to be provided. 754 */ 755 if (!test_bit(SP_CONGESTED, &pool->sp_flags)) 756 rqstp->rq_chandle.thread_wait = 5*HZ; 757 else 758 rqstp->rq_chandle.thread_wait = 1*HZ; 759 trace_svc_xprt_dequeue(rqstp); 760 return rqstp->rq_xprt; 761 } 762 763 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 764 { 765 spin_lock_bh(&serv->sv_lock); 766 set_bit(XPT_TEMP, &newxpt->xpt_flags); 767 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 768 serv->sv_tmpcnt++; 769 if (serv->sv_temptimer.function == NULL) { 770 /* setup timer to age temp transports */ 771 serv->sv_temptimer.function = svc_age_temp_xprts; 772 mod_timer(&serv->sv_temptimer, 773 jiffies + svc_conn_age_period * HZ); 774 } 775 spin_unlock_bh(&serv->sv_lock); 776 svc_xprt_received(newxpt); 777 } 778 779 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 780 { 781 struct svc_serv *serv = rqstp->rq_server; 782 int len = 0; 783 784 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 785 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 786 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 787 svc_delete_xprt(xprt); 788 /* Leave XPT_BUSY set on the dead xprt: */ 789 goto out; 790 } 791 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 792 struct svc_xprt *newxpt; 793 /* 794 * We know this module_get will succeed because the 795 * listener holds a reference too 796 */ 797 __module_get(xprt->xpt_class->xcl_owner); 798 svc_check_conn_limits(xprt->xpt_server); 799 newxpt = xprt->xpt_ops->xpo_accept(xprt); 800 if (newxpt) { 801 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 802 svc_add_new_temp_xprt(serv, newxpt); 803 trace_svc_xprt_accept(newxpt, serv->sv_name); 804 } else 805 module_put(xprt->xpt_class->xcl_owner); 806 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 807 /* XPT_DATA|XPT_DEFERRED case: */ 808 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 809 rqstp, rqstp->rq_pool->sp_id, xprt, 810 kref_read(&xprt->xpt_ref)); 811 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 812 if (rqstp->rq_deferred) 813 len = svc_deferred_recv(rqstp); 814 else 815 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 816 rqstp->rq_stime = ktime_get(); 817 rqstp->rq_reserved = serv->sv_max_mesg; 818 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 819 } 820 /* clear XPT_BUSY: */ 821 svc_xprt_received(xprt); 822 out: 823 trace_svc_handle_xprt(xprt, len); 824 return len; 825 } 826 827 /* 828 * Receive the next request on any transport. This code is carefully 829 * organised not to touch any cachelines in the shared svc_serv 830 * structure, only cachelines in the local svc_pool. 831 */ 832 int svc_recv(struct svc_rqst *rqstp, long timeout) 833 { 834 struct svc_xprt *xprt = NULL; 835 struct svc_serv *serv = rqstp->rq_server; 836 int len, err; 837 838 err = svc_alloc_arg(rqstp); 839 if (err) 840 goto out; 841 842 try_to_freeze(); 843 cond_resched(); 844 err = -EINTR; 845 if (signalled() || kthread_should_stop()) 846 goto out; 847 848 xprt = svc_get_next_xprt(rqstp, timeout); 849 if (IS_ERR(xprt)) { 850 err = PTR_ERR(xprt); 851 goto out; 852 } 853 854 len = svc_handle_xprt(rqstp, xprt); 855 856 /* No data, incomplete (TCP) read, or accept() */ 857 err = -EAGAIN; 858 if (len <= 0) 859 goto out_release; 860 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 861 862 clear_bit(XPT_OLD, &xprt->xpt_flags); 863 864 xprt->xpt_ops->xpo_secure_port(rqstp); 865 rqstp->rq_chandle.defer = svc_defer; 866 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 867 868 if (serv->sv_stats) 869 serv->sv_stats->netcnt++; 870 return len; 871 out_release: 872 rqstp->rq_res.len = 0; 873 svc_xprt_release(rqstp); 874 out: 875 return err; 876 } 877 EXPORT_SYMBOL_GPL(svc_recv); 878 879 /* 880 * Drop request 881 */ 882 void svc_drop(struct svc_rqst *rqstp) 883 { 884 trace_svc_drop(rqstp); 885 svc_xprt_release(rqstp); 886 } 887 EXPORT_SYMBOL_GPL(svc_drop); 888 889 /* 890 * Return reply to client. 891 */ 892 int svc_send(struct svc_rqst *rqstp) 893 { 894 struct svc_xprt *xprt; 895 int len = -EFAULT; 896 struct xdr_buf *xb; 897 898 xprt = rqstp->rq_xprt; 899 if (!xprt) 900 goto out; 901 902 /* calculate over-all length */ 903 xb = &rqstp->rq_res; 904 xb->len = xb->head[0].iov_len + 905 xb->page_len + 906 xb->tail[0].iov_len; 907 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 908 trace_svc_stats_latency(rqstp); 909 910 len = xprt->xpt_ops->xpo_sendto(rqstp); 911 912 trace_svc_send(rqstp, len); 913 svc_xprt_release(rqstp); 914 915 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 916 len = 0; 917 out: 918 return len; 919 } 920 921 /* 922 * Timer function to close old temporary transports, using 923 * a mark-and-sweep algorithm. 924 */ 925 static void svc_age_temp_xprts(struct timer_list *t) 926 { 927 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 928 struct svc_xprt *xprt; 929 struct list_head *le, *next; 930 931 dprintk("svc_age_temp_xprts\n"); 932 933 if (!spin_trylock_bh(&serv->sv_lock)) { 934 /* busy, try again 1 sec later */ 935 dprintk("svc_age_temp_xprts: busy\n"); 936 mod_timer(&serv->sv_temptimer, jiffies + HZ); 937 return; 938 } 939 940 list_for_each_safe(le, next, &serv->sv_tempsocks) { 941 xprt = list_entry(le, struct svc_xprt, xpt_list); 942 943 /* First time through, just mark it OLD. Second time 944 * through, close it. */ 945 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 946 continue; 947 if (kref_read(&xprt->xpt_ref) > 1 || 948 test_bit(XPT_BUSY, &xprt->xpt_flags)) 949 continue; 950 list_del_init(le); 951 set_bit(XPT_CLOSE, &xprt->xpt_flags); 952 dprintk("queuing xprt %p for closing\n", xprt); 953 954 /* a thread will dequeue and close it soon */ 955 svc_xprt_enqueue(xprt); 956 } 957 spin_unlock_bh(&serv->sv_lock); 958 959 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 960 } 961 962 /* Close temporary transports whose xpt_local matches server_addr immediately 963 * instead of waiting for them to be picked up by the timer. 964 * 965 * This is meant to be called from a notifier_block that runs when an ip 966 * address is deleted. 967 */ 968 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 969 { 970 struct svc_xprt *xprt; 971 struct list_head *le, *next; 972 LIST_HEAD(to_be_closed); 973 974 spin_lock_bh(&serv->sv_lock); 975 list_for_each_safe(le, next, &serv->sv_tempsocks) { 976 xprt = list_entry(le, struct svc_xprt, xpt_list); 977 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 978 &xprt->xpt_local)) { 979 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 980 list_move(le, &to_be_closed); 981 } 982 } 983 spin_unlock_bh(&serv->sv_lock); 984 985 while (!list_empty(&to_be_closed)) { 986 le = to_be_closed.next; 987 list_del_init(le); 988 xprt = list_entry(le, struct svc_xprt, xpt_list); 989 set_bit(XPT_CLOSE, &xprt->xpt_flags); 990 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 991 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 992 xprt); 993 svc_xprt_enqueue(xprt); 994 } 995 } 996 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 997 998 static void call_xpt_users(struct svc_xprt *xprt) 999 { 1000 struct svc_xpt_user *u; 1001 1002 spin_lock(&xprt->xpt_lock); 1003 while (!list_empty(&xprt->xpt_users)) { 1004 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1005 list_del_init(&u->list); 1006 u->callback(u); 1007 } 1008 spin_unlock(&xprt->xpt_lock); 1009 } 1010 1011 /* 1012 * Remove a dead transport 1013 */ 1014 static void svc_delete_xprt(struct svc_xprt *xprt) 1015 { 1016 struct svc_serv *serv = xprt->xpt_server; 1017 struct svc_deferred_req *dr; 1018 1019 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1020 return; 1021 1022 trace_svc_xprt_detach(xprt); 1023 xprt->xpt_ops->xpo_detach(xprt); 1024 if (xprt->xpt_bc_xprt) 1025 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1026 1027 spin_lock_bh(&serv->sv_lock); 1028 list_del_init(&xprt->xpt_list); 1029 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 1030 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1031 serv->sv_tmpcnt--; 1032 spin_unlock_bh(&serv->sv_lock); 1033 1034 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1035 kfree(dr); 1036 1037 call_xpt_users(xprt); 1038 svc_xprt_put(xprt); 1039 } 1040 1041 void svc_close_xprt(struct svc_xprt *xprt) 1042 { 1043 trace_svc_xprt_close(xprt); 1044 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1045 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1046 /* someone else will have to effect the close */ 1047 return; 1048 /* 1049 * We expect svc_close_xprt() to work even when no threads are 1050 * running (e.g., while configuring the server before starting 1051 * any threads), so if the transport isn't busy, we delete 1052 * it ourself: 1053 */ 1054 svc_delete_xprt(xprt); 1055 } 1056 EXPORT_SYMBOL_GPL(svc_close_xprt); 1057 1058 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1059 { 1060 struct svc_xprt *xprt; 1061 int ret = 0; 1062 1063 spin_lock(&serv->sv_lock); 1064 list_for_each_entry(xprt, xprt_list, xpt_list) { 1065 if (xprt->xpt_net != net) 1066 continue; 1067 ret++; 1068 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1069 svc_xprt_enqueue(xprt); 1070 } 1071 spin_unlock(&serv->sv_lock); 1072 return ret; 1073 } 1074 1075 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1076 { 1077 struct svc_pool *pool; 1078 struct svc_xprt *xprt; 1079 struct svc_xprt *tmp; 1080 int i; 1081 1082 for (i = 0; i < serv->sv_nrpools; i++) { 1083 pool = &serv->sv_pools[i]; 1084 1085 spin_lock_bh(&pool->sp_lock); 1086 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1087 if (xprt->xpt_net != net) 1088 continue; 1089 list_del_init(&xprt->xpt_ready); 1090 spin_unlock_bh(&pool->sp_lock); 1091 return xprt; 1092 } 1093 spin_unlock_bh(&pool->sp_lock); 1094 } 1095 return NULL; 1096 } 1097 1098 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1099 { 1100 struct svc_xprt *xprt; 1101 1102 while ((xprt = svc_dequeue_net(serv, net))) { 1103 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1104 svc_delete_xprt(xprt); 1105 } 1106 } 1107 1108 /* 1109 * Server threads may still be running (especially in the case where the 1110 * service is still running in other network namespaces). 1111 * 1112 * So we shut down sockets the same way we would on a running server, by 1113 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1114 * the close. In the case there are no such other threads, 1115 * threads running, svc_clean_up_xprts() does a simple version of a 1116 * server's main event loop, and in the case where there are other 1117 * threads, we may need to wait a little while and then check again to 1118 * see if they're done. 1119 */ 1120 void svc_close_net(struct svc_serv *serv, struct net *net) 1121 { 1122 int delay = 0; 1123 1124 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1125 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1126 1127 svc_clean_up_xprts(serv, net); 1128 msleep(delay++); 1129 } 1130 } 1131 1132 /* 1133 * Handle defer and revisit of requests 1134 */ 1135 1136 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1137 { 1138 struct svc_deferred_req *dr = 1139 container_of(dreq, struct svc_deferred_req, handle); 1140 struct svc_xprt *xprt = dr->xprt; 1141 1142 spin_lock(&xprt->xpt_lock); 1143 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1144 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1145 spin_unlock(&xprt->xpt_lock); 1146 trace_svc_defer_drop(dr); 1147 svc_xprt_put(xprt); 1148 kfree(dr); 1149 return; 1150 } 1151 dr->xprt = NULL; 1152 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1153 spin_unlock(&xprt->xpt_lock); 1154 trace_svc_defer_queue(dr); 1155 svc_xprt_enqueue(xprt); 1156 svc_xprt_put(xprt); 1157 } 1158 1159 /* 1160 * Save the request off for later processing. The request buffer looks 1161 * like this: 1162 * 1163 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1164 * 1165 * This code can only handle requests that consist of an xprt-header 1166 * and rpc-header. 1167 */ 1168 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1169 { 1170 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1171 struct svc_deferred_req *dr; 1172 1173 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1174 return NULL; /* if more than a page, give up FIXME */ 1175 if (rqstp->rq_deferred) { 1176 dr = rqstp->rq_deferred; 1177 rqstp->rq_deferred = NULL; 1178 } else { 1179 size_t skip; 1180 size_t size; 1181 /* FIXME maybe discard if size too large */ 1182 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1183 dr = kmalloc(size, GFP_KERNEL); 1184 if (dr == NULL) 1185 return NULL; 1186 1187 dr->handle.owner = rqstp->rq_server; 1188 dr->prot = rqstp->rq_prot; 1189 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1190 dr->addrlen = rqstp->rq_addrlen; 1191 dr->daddr = rqstp->rq_daddr; 1192 dr->argslen = rqstp->rq_arg.len >> 2; 1193 dr->xprt_hlen = rqstp->rq_xprt_hlen; 1194 1195 /* back up head to the start of the buffer and copy */ 1196 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1197 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1198 dr->argslen << 2); 1199 } 1200 trace_svc_defer(rqstp); 1201 svc_xprt_get(rqstp->rq_xprt); 1202 dr->xprt = rqstp->rq_xprt; 1203 set_bit(RQ_DROPME, &rqstp->rq_flags); 1204 1205 dr->handle.revisit = svc_revisit; 1206 return &dr->handle; 1207 } 1208 1209 /* 1210 * recv data from a deferred request into an active one 1211 */ 1212 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1213 { 1214 struct svc_deferred_req *dr = rqstp->rq_deferred; 1215 1216 trace_svc_defer_recv(dr); 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