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 /** 143 * svc_xprt_deferred_close - Close a transport 144 * @xprt: transport instance 145 * 146 * Used in contexts that need to defer the work of shutting down 147 * the transport to an nfsd thread. 148 */ 149 void svc_xprt_deferred_close(struct svc_xprt *xprt) 150 { 151 if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags)) 152 svc_xprt_enqueue(xprt); 153 } 154 EXPORT_SYMBOL_GPL(svc_xprt_deferred_close); 155 156 static void svc_xprt_free(struct kref *kref) 157 { 158 struct svc_xprt *xprt = 159 container_of(kref, struct svc_xprt, xpt_ref); 160 struct module *owner = xprt->xpt_class->xcl_owner; 161 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 162 svcauth_unix_info_release(xprt); 163 put_cred(xprt->xpt_cred); 164 put_net(xprt->xpt_net); 165 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 166 if (xprt->xpt_bc_xprt) 167 xprt_put(xprt->xpt_bc_xprt); 168 if (xprt->xpt_bc_xps) 169 xprt_switch_put(xprt->xpt_bc_xps); 170 trace_svc_xprt_free(xprt); 171 xprt->xpt_ops->xpo_free(xprt); 172 module_put(owner); 173 } 174 175 void svc_xprt_put(struct svc_xprt *xprt) 176 { 177 kref_put(&xprt->xpt_ref, svc_xprt_free); 178 } 179 EXPORT_SYMBOL_GPL(svc_xprt_put); 180 181 /* 182 * Called by transport drivers to initialize the transport independent 183 * portion of the transport instance. 184 */ 185 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 186 struct svc_xprt *xprt, struct svc_serv *serv) 187 { 188 memset(xprt, 0, sizeof(*xprt)); 189 xprt->xpt_class = xcl; 190 xprt->xpt_ops = xcl->xcl_ops; 191 kref_init(&xprt->xpt_ref); 192 xprt->xpt_server = serv; 193 INIT_LIST_HEAD(&xprt->xpt_list); 194 INIT_LIST_HEAD(&xprt->xpt_ready); 195 INIT_LIST_HEAD(&xprt->xpt_deferred); 196 INIT_LIST_HEAD(&xprt->xpt_users); 197 mutex_init(&xprt->xpt_mutex); 198 spin_lock_init(&xprt->xpt_lock); 199 set_bit(XPT_BUSY, &xprt->xpt_flags); 200 xprt->xpt_net = get_net(net); 201 strcpy(xprt->xpt_remotebuf, "uninitialized"); 202 } 203 EXPORT_SYMBOL_GPL(svc_xprt_init); 204 205 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 206 struct svc_serv *serv, 207 struct net *net, 208 const int family, 209 const unsigned short port, 210 int flags) 211 { 212 struct sockaddr_in sin = { 213 .sin_family = AF_INET, 214 .sin_addr.s_addr = htonl(INADDR_ANY), 215 .sin_port = htons(port), 216 }; 217 #if IS_ENABLED(CONFIG_IPV6) 218 struct sockaddr_in6 sin6 = { 219 .sin6_family = AF_INET6, 220 .sin6_addr = IN6ADDR_ANY_INIT, 221 .sin6_port = htons(port), 222 }; 223 #endif 224 struct svc_xprt *xprt; 225 struct sockaddr *sap; 226 size_t len; 227 228 switch (family) { 229 case PF_INET: 230 sap = (struct sockaddr *)&sin; 231 len = sizeof(sin); 232 break; 233 #if IS_ENABLED(CONFIG_IPV6) 234 case PF_INET6: 235 sap = (struct sockaddr *)&sin6; 236 len = sizeof(sin6); 237 break; 238 #endif 239 default: 240 return ERR_PTR(-EAFNOSUPPORT); 241 } 242 243 xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 244 if (IS_ERR(xprt)) 245 trace_svc_xprt_create_err(serv->sv_program->pg_name, 246 xcl->xcl_name, sap, xprt); 247 return xprt; 248 } 249 250 /** 251 * svc_xprt_received - start next receiver thread 252 * @xprt: controlling transport 253 * 254 * The caller must hold the XPT_BUSY bit and must 255 * not thereafter touch transport data. 256 * 257 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 258 * insufficient) data. 259 */ 260 void svc_xprt_received(struct svc_xprt *xprt) 261 { 262 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 263 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 264 return; 265 } 266 267 trace_svc_xprt_received(xprt); 268 269 /* As soon as we clear busy, the xprt could be closed and 270 * 'put', so we need a reference to call svc_enqueue_xprt with: 271 */ 272 svc_xprt_get(xprt); 273 smp_mb__before_atomic(); 274 clear_bit(XPT_BUSY, &xprt->xpt_flags); 275 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 276 svc_xprt_put(xprt); 277 } 278 EXPORT_SYMBOL_GPL(svc_xprt_received); 279 280 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 281 { 282 clear_bit(XPT_TEMP, &new->xpt_flags); 283 spin_lock_bh(&serv->sv_lock); 284 list_add(&new->xpt_list, &serv->sv_permsocks); 285 spin_unlock_bh(&serv->sv_lock); 286 svc_xprt_received(new); 287 } 288 289 static int _svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 290 struct net *net, const int family, 291 const unsigned short port, int flags, 292 const struct cred *cred) 293 { 294 struct svc_xprt_class *xcl; 295 296 spin_lock(&svc_xprt_class_lock); 297 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 298 struct svc_xprt *newxprt; 299 unsigned short newport; 300 301 if (strcmp(xprt_name, xcl->xcl_name)) 302 continue; 303 304 if (!try_module_get(xcl->xcl_owner)) 305 goto err; 306 307 spin_unlock(&svc_xprt_class_lock); 308 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 309 if (IS_ERR(newxprt)) { 310 module_put(xcl->xcl_owner); 311 return PTR_ERR(newxprt); 312 } 313 newxprt->xpt_cred = get_cred(cred); 314 svc_add_new_perm_xprt(serv, newxprt); 315 newport = svc_xprt_local_port(newxprt); 316 return newport; 317 } 318 err: 319 spin_unlock(&svc_xprt_class_lock); 320 /* This errno is exposed to user space. Provide a reasonable 321 * perror msg for a bad transport. */ 322 return -EPROTONOSUPPORT; 323 } 324 325 int svc_create_xprt(struct svc_serv *serv, const char *xprt_name, 326 struct net *net, const int family, 327 const unsigned short port, int flags, 328 const struct cred *cred) 329 { 330 int err; 331 332 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); 333 if (err == -EPROTONOSUPPORT) { 334 request_module("svc%s", xprt_name); 335 err = _svc_create_xprt(serv, xprt_name, net, family, port, flags, cred); 336 } 337 return err; 338 } 339 EXPORT_SYMBOL_GPL(svc_create_xprt); 340 341 /* 342 * Copy the local and remote xprt addresses to the rqstp structure 343 */ 344 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 345 { 346 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 347 rqstp->rq_addrlen = xprt->xpt_remotelen; 348 349 /* 350 * Destination address in request is needed for binding the 351 * source address in RPC replies/callbacks later. 352 */ 353 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 354 rqstp->rq_daddrlen = xprt->xpt_locallen; 355 } 356 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 357 358 /** 359 * svc_print_addr - Format rq_addr field for printing 360 * @rqstp: svc_rqst struct containing address to print 361 * @buf: target buffer for formatted address 362 * @len: length of target buffer 363 * 364 */ 365 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 366 { 367 return __svc_print_addr(svc_addr(rqstp), buf, len); 368 } 369 EXPORT_SYMBOL_GPL(svc_print_addr); 370 371 static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) 372 { 373 unsigned int limit = svc_rpc_per_connection_limit; 374 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); 375 376 return limit == 0 || (nrqsts >= 0 && nrqsts < limit); 377 } 378 379 static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) 380 { 381 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { 382 if (!svc_xprt_slots_in_range(xprt)) 383 return false; 384 atomic_inc(&xprt->xpt_nr_rqsts); 385 set_bit(RQ_DATA, &rqstp->rq_flags); 386 } 387 return true; 388 } 389 390 static void svc_xprt_release_slot(struct svc_rqst *rqstp) 391 { 392 struct svc_xprt *xprt = rqstp->rq_xprt; 393 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { 394 atomic_dec(&xprt->xpt_nr_rqsts); 395 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 396 svc_xprt_enqueue(xprt); 397 } 398 } 399 400 static bool svc_xprt_ready(struct svc_xprt *xprt) 401 { 402 unsigned long xpt_flags; 403 404 /* 405 * If another cpu has recently updated xpt_flags, 406 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to 407 * know about it; otherwise it's possible that both that cpu and 408 * this one could call svc_xprt_enqueue() without either 409 * svc_xprt_enqueue() recognizing that the conditions below 410 * are satisfied, and we could stall indefinitely: 411 */ 412 smp_rmb(); 413 xpt_flags = READ_ONCE(xprt->xpt_flags); 414 415 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) 416 return true; 417 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { 418 if (xprt->xpt_ops->xpo_has_wspace(xprt) && 419 svc_xprt_slots_in_range(xprt)) 420 return true; 421 trace_svc_xprt_no_write_space(xprt); 422 return false; 423 } 424 return false; 425 } 426 427 void svc_xprt_do_enqueue(struct svc_xprt *xprt) 428 { 429 struct svc_pool *pool; 430 struct svc_rqst *rqstp = NULL; 431 int cpu; 432 433 if (!svc_xprt_ready(xprt)) 434 return; 435 436 /* Mark transport as busy. It will remain in this state until 437 * the provider calls svc_xprt_received. We update XPT_BUSY 438 * atomically because it also guards against trying to enqueue 439 * the transport twice. 440 */ 441 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 442 return; 443 444 cpu = get_cpu(); 445 pool = svc_pool_for_cpu(xprt->xpt_server, cpu); 446 447 atomic_long_inc(&pool->sp_stats.packets); 448 449 spin_lock_bh(&pool->sp_lock); 450 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 451 pool->sp_stats.sockets_queued++; 452 spin_unlock_bh(&pool->sp_lock); 453 454 /* find a thread for this xprt */ 455 rcu_read_lock(); 456 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 457 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) 458 continue; 459 atomic_long_inc(&pool->sp_stats.threads_woken); 460 rqstp->rq_qtime = ktime_get(); 461 wake_up_process(rqstp->rq_task); 462 goto out_unlock; 463 } 464 set_bit(SP_CONGESTED, &pool->sp_flags); 465 rqstp = NULL; 466 out_unlock: 467 rcu_read_unlock(); 468 put_cpu(); 469 trace_svc_xprt_do_enqueue(xprt, rqstp); 470 } 471 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); 472 473 /* 474 * Queue up a transport with data pending. If there are idle nfsd 475 * processes, wake 'em up. 476 * 477 */ 478 void svc_xprt_enqueue(struct svc_xprt *xprt) 479 { 480 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) 481 return; 482 xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); 483 } 484 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 485 486 /* 487 * Dequeue the first transport, if there is one. 488 */ 489 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 490 { 491 struct svc_xprt *xprt = NULL; 492 493 if (list_empty(&pool->sp_sockets)) 494 goto out; 495 496 spin_lock_bh(&pool->sp_lock); 497 if (likely(!list_empty(&pool->sp_sockets))) { 498 xprt = list_first_entry(&pool->sp_sockets, 499 struct svc_xprt, xpt_ready); 500 list_del_init(&xprt->xpt_ready); 501 svc_xprt_get(xprt); 502 } 503 spin_unlock_bh(&pool->sp_lock); 504 out: 505 return xprt; 506 } 507 508 /** 509 * svc_reserve - change the space reserved for the reply to a request. 510 * @rqstp: The request in question 511 * @space: new max space to reserve 512 * 513 * Each request reserves some space on the output queue of the transport 514 * to make sure the reply fits. This function reduces that reserved 515 * space to be the amount of space used already, plus @space. 516 * 517 */ 518 void svc_reserve(struct svc_rqst *rqstp, int space) 519 { 520 struct svc_xprt *xprt = rqstp->rq_xprt; 521 522 space += rqstp->rq_res.head[0].iov_len; 523 524 if (xprt && space < rqstp->rq_reserved) { 525 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 526 rqstp->rq_reserved = space; 527 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 528 svc_xprt_enqueue(xprt); 529 } 530 } 531 EXPORT_SYMBOL_GPL(svc_reserve); 532 533 static void svc_xprt_release(struct svc_rqst *rqstp) 534 { 535 struct svc_xprt *xprt = rqstp->rq_xprt; 536 537 xprt->xpt_ops->xpo_release_rqst(rqstp); 538 539 kfree(rqstp->rq_deferred); 540 rqstp->rq_deferred = NULL; 541 542 svc_free_res_pages(rqstp); 543 rqstp->rq_res.page_len = 0; 544 rqstp->rq_res.page_base = 0; 545 546 /* Reset response buffer and release 547 * the reservation. 548 * But first, check that enough space was reserved 549 * for the reply, otherwise we have a bug! 550 */ 551 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 552 printk(KERN_ERR "RPC request reserved %d but used %d\n", 553 rqstp->rq_reserved, 554 rqstp->rq_res.len); 555 556 rqstp->rq_res.head[0].iov_len = 0; 557 svc_reserve(rqstp, 0); 558 svc_xprt_release_slot(rqstp); 559 rqstp->rq_xprt = NULL; 560 svc_xprt_put(xprt); 561 } 562 563 /* 564 * Some svc_serv's will have occasional work to do, even when a xprt is not 565 * waiting to be serviced. This function is there to "kick" a task in one of 566 * those services so that it can wake up and do that work. Note that we only 567 * bother with pool 0 as we don't need to wake up more than one thread for 568 * this purpose. 569 */ 570 void svc_wake_up(struct svc_serv *serv) 571 { 572 struct svc_rqst *rqstp; 573 struct svc_pool *pool; 574 575 pool = &serv->sv_pools[0]; 576 577 rcu_read_lock(); 578 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 579 /* skip any that aren't queued */ 580 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 581 continue; 582 rcu_read_unlock(); 583 wake_up_process(rqstp->rq_task); 584 trace_svc_wake_up(rqstp->rq_task->pid); 585 return; 586 } 587 rcu_read_unlock(); 588 589 /* No free entries available */ 590 set_bit(SP_TASK_PENDING, &pool->sp_flags); 591 smp_wmb(); 592 trace_svc_wake_up(0); 593 } 594 EXPORT_SYMBOL_GPL(svc_wake_up); 595 596 int svc_port_is_privileged(struct sockaddr *sin) 597 { 598 switch (sin->sa_family) { 599 case AF_INET: 600 return ntohs(((struct sockaddr_in *)sin)->sin_port) 601 < PROT_SOCK; 602 case AF_INET6: 603 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 604 < PROT_SOCK; 605 default: 606 return 0; 607 } 608 } 609 610 /* 611 * Make sure that we don't have too many active connections. If we have, 612 * something must be dropped. It's not clear what will happen if we allow 613 * "too many" connections, but when dealing with network-facing software, 614 * we have to code defensively. Here we do that by imposing hard limits. 615 * 616 * There's no point in trying to do random drop here for DoS 617 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 618 * attacker can easily beat that. 619 * 620 * The only somewhat efficient mechanism would be if drop old 621 * connections from the same IP first. But right now we don't even 622 * record the client IP in svc_sock. 623 * 624 * single-threaded services that expect a lot of clients will probably 625 * need to set sv_maxconn to override the default value which is based 626 * on the number of threads 627 */ 628 static void svc_check_conn_limits(struct svc_serv *serv) 629 { 630 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 631 (serv->sv_nrthreads+3) * 20; 632 633 if (serv->sv_tmpcnt > limit) { 634 struct svc_xprt *xprt = NULL; 635 spin_lock_bh(&serv->sv_lock); 636 if (!list_empty(&serv->sv_tempsocks)) { 637 /* Try to help the admin */ 638 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 639 serv->sv_name, serv->sv_maxconn ? 640 "max number of connections" : 641 "number of threads"); 642 /* 643 * Always select the oldest connection. It's not fair, 644 * but so is life 645 */ 646 xprt = list_entry(serv->sv_tempsocks.prev, 647 struct svc_xprt, 648 xpt_list); 649 set_bit(XPT_CLOSE, &xprt->xpt_flags); 650 svc_xprt_get(xprt); 651 } 652 spin_unlock_bh(&serv->sv_lock); 653 654 if (xprt) { 655 svc_xprt_enqueue(xprt); 656 svc_xprt_put(xprt); 657 } 658 } 659 } 660 661 static int svc_alloc_arg(struct svc_rqst *rqstp) 662 { 663 struct svc_serv *serv = rqstp->rq_server; 664 struct xdr_buf *arg = &rqstp->rq_arg; 665 unsigned long pages, filled; 666 667 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 668 if (pages > RPCSVC_MAXPAGES) { 669 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", 670 pages, RPCSVC_MAXPAGES); 671 /* use as many pages as possible */ 672 pages = RPCSVC_MAXPAGES; 673 } 674 675 for (;;) { 676 filled = alloc_pages_bulk_array(GFP_KERNEL, pages, 677 rqstp->rq_pages); 678 if (filled == pages) 679 break; 680 681 set_current_state(TASK_INTERRUPTIBLE); 682 if (signalled() || kthread_should_stop()) { 683 set_current_state(TASK_RUNNING); 684 return -EINTR; 685 } 686 schedule_timeout(msecs_to_jiffies(500)); 687 } 688 rqstp->rq_page_end = &rqstp->rq_pages[pages]; 689 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ 690 691 /* Make arg->head point to first page and arg->pages point to rest */ 692 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 693 arg->head[0].iov_len = PAGE_SIZE; 694 arg->pages = rqstp->rq_pages + 1; 695 arg->page_base = 0; 696 /* save at least one page for response */ 697 arg->page_len = (pages-2)*PAGE_SIZE; 698 arg->len = (pages-1)*PAGE_SIZE; 699 arg->tail[0].iov_len = 0; 700 return 0; 701 } 702 703 static bool 704 rqst_should_sleep(struct svc_rqst *rqstp) 705 { 706 struct svc_pool *pool = rqstp->rq_pool; 707 708 /* did someone call svc_wake_up? */ 709 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 710 return false; 711 712 /* was a socket queued? */ 713 if (!list_empty(&pool->sp_sockets)) 714 return false; 715 716 /* are we shutting down? */ 717 if (signalled() || kthread_should_stop()) 718 return false; 719 720 /* are we freezing? */ 721 if (freezing(current)) 722 return false; 723 724 return true; 725 } 726 727 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 728 { 729 struct svc_pool *pool = rqstp->rq_pool; 730 long time_left = 0; 731 732 /* rq_xprt should be clear on entry */ 733 WARN_ON_ONCE(rqstp->rq_xprt); 734 735 rqstp->rq_xprt = svc_xprt_dequeue(pool); 736 if (rqstp->rq_xprt) 737 goto out_found; 738 739 /* 740 * We have to be able to interrupt this wait 741 * to bring down the daemons ... 742 */ 743 set_current_state(TASK_INTERRUPTIBLE); 744 smp_mb__before_atomic(); 745 clear_bit(SP_CONGESTED, &pool->sp_flags); 746 clear_bit(RQ_BUSY, &rqstp->rq_flags); 747 smp_mb__after_atomic(); 748 749 if (likely(rqst_should_sleep(rqstp))) 750 time_left = schedule_timeout(timeout); 751 else 752 __set_current_state(TASK_RUNNING); 753 754 try_to_freeze(); 755 756 set_bit(RQ_BUSY, &rqstp->rq_flags); 757 smp_mb__after_atomic(); 758 rqstp->rq_xprt = svc_xprt_dequeue(pool); 759 if (rqstp->rq_xprt) 760 goto out_found; 761 762 if (!time_left) 763 atomic_long_inc(&pool->sp_stats.threads_timedout); 764 765 if (signalled() || kthread_should_stop()) 766 return ERR_PTR(-EINTR); 767 return ERR_PTR(-EAGAIN); 768 out_found: 769 /* Normally we will wait up to 5 seconds for any required 770 * cache information to be provided. 771 */ 772 if (!test_bit(SP_CONGESTED, &pool->sp_flags)) 773 rqstp->rq_chandle.thread_wait = 5*HZ; 774 else 775 rqstp->rq_chandle.thread_wait = 1*HZ; 776 trace_svc_xprt_dequeue(rqstp); 777 return rqstp->rq_xprt; 778 } 779 780 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 781 { 782 spin_lock_bh(&serv->sv_lock); 783 set_bit(XPT_TEMP, &newxpt->xpt_flags); 784 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 785 serv->sv_tmpcnt++; 786 if (serv->sv_temptimer.function == NULL) { 787 /* setup timer to age temp transports */ 788 serv->sv_temptimer.function = svc_age_temp_xprts; 789 mod_timer(&serv->sv_temptimer, 790 jiffies + svc_conn_age_period * HZ); 791 } 792 spin_unlock_bh(&serv->sv_lock); 793 svc_xprt_received(newxpt); 794 } 795 796 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 797 { 798 struct svc_serv *serv = rqstp->rq_server; 799 int len = 0; 800 801 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 802 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 803 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 804 svc_delete_xprt(xprt); 805 /* Leave XPT_BUSY set on the dead xprt: */ 806 goto out; 807 } 808 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 809 struct svc_xprt *newxpt; 810 /* 811 * We know this module_get will succeed because the 812 * listener holds a reference too 813 */ 814 __module_get(xprt->xpt_class->xcl_owner); 815 svc_check_conn_limits(xprt->xpt_server); 816 newxpt = xprt->xpt_ops->xpo_accept(xprt); 817 if (newxpt) { 818 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 819 svc_add_new_temp_xprt(serv, newxpt); 820 trace_svc_xprt_accept(newxpt, serv->sv_name); 821 } else { 822 module_put(xprt->xpt_class->xcl_owner); 823 } 824 svc_xprt_received(xprt); 825 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 826 /* XPT_DATA|XPT_DEFERRED case: */ 827 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 828 rqstp, rqstp->rq_pool->sp_id, xprt, 829 kref_read(&xprt->xpt_ref)); 830 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 831 if (rqstp->rq_deferred) 832 len = svc_deferred_recv(rqstp); 833 else 834 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 835 rqstp->rq_stime = ktime_get(); 836 rqstp->rq_reserved = serv->sv_max_mesg; 837 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 838 } 839 out: 840 trace_svc_handle_xprt(xprt, len); 841 return len; 842 } 843 844 /* 845 * Receive the next request on any transport. This code is carefully 846 * organised not to touch any cachelines in the shared svc_serv 847 * structure, only cachelines in the local svc_pool. 848 */ 849 int svc_recv(struct svc_rqst *rqstp, long timeout) 850 { 851 struct svc_xprt *xprt = NULL; 852 struct svc_serv *serv = rqstp->rq_server; 853 int len, err; 854 855 err = svc_alloc_arg(rqstp); 856 if (err) 857 goto out; 858 859 try_to_freeze(); 860 cond_resched(); 861 err = -EINTR; 862 if (signalled() || kthread_should_stop()) 863 goto out; 864 865 xprt = svc_get_next_xprt(rqstp, timeout); 866 if (IS_ERR(xprt)) { 867 err = PTR_ERR(xprt); 868 goto out; 869 } 870 871 len = svc_handle_xprt(rqstp, xprt); 872 873 /* No data, incomplete (TCP) read, or accept() */ 874 err = -EAGAIN; 875 if (len <= 0) 876 goto out_release; 877 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 878 879 clear_bit(XPT_OLD, &xprt->xpt_flags); 880 881 xprt->xpt_ops->xpo_secure_port(rqstp); 882 rqstp->rq_chandle.defer = svc_defer; 883 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 884 885 if (serv->sv_stats) 886 serv->sv_stats->netcnt++; 887 return len; 888 out_release: 889 rqstp->rq_res.len = 0; 890 svc_xprt_release(rqstp); 891 out: 892 return err; 893 } 894 EXPORT_SYMBOL_GPL(svc_recv); 895 896 /* 897 * Drop request 898 */ 899 void svc_drop(struct svc_rqst *rqstp) 900 { 901 trace_svc_drop(rqstp); 902 svc_xprt_release(rqstp); 903 } 904 EXPORT_SYMBOL_GPL(svc_drop); 905 906 /* 907 * Return reply to client. 908 */ 909 int svc_send(struct svc_rqst *rqstp) 910 { 911 struct svc_xprt *xprt; 912 int len = -EFAULT; 913 struct xdr_buf *xb; 914 915 xprt = rqstp->rq_xprt; 916 if (!xprt) 917 goto out; 918 919 /* calculate over-all length */ 920 xb = &rqstp->rq_res; 921 xb->len = xb->head[0].iov_len + 922 xb->page_len + 923 xb->tail[0].iov_len; 924 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 925 trace_svc_stats_latency(rqstp); 926 927 len = xprt->xpt_ops->xpo_sendto(rqstp); 928 929 trace_svc_send(rqstp, len); 930 svc_xprt_release(rqstp); 931 932 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 933 len = 0; 934 out: 935 return len; 936 } 937 938 /* 939 * Timer function to close old temporary transports, using 940 * a mark-and-sweep algorithm. 941 */ 942 static void svc_age_temp_xprts(struct timer_list *t) 943 { 944 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 945 struct svc_xprt *xprt; 946 struct list_head *le, *next; 947 948 dprintk("svc_age_temp_xprts\n"); 949 950 if (!spin_trylock_bh(&serv->sv_lock)) { 951 /* busy, try again 1 sec later */ 952 dprintk("svc_age_temp_xprts: busy\n"); 953 mod_timer(&serv->sv_temptimer, jiffies + HZ); 954 return; 955 } 956 957 list_for_each_safe(le, next, &serv->sv_tempsocks) { 958 xprt = list_entry(le, struct svc_xprt, xpt_list); 959 960 /* First time through, just mark it OLD. Second time 961 * through, close it. */ 962 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 963 continue; 964 if (kref_read(&xprt->xpt_ref) > 1 || 965 test_bit(XPT_BUSY, &xprt->xpt_flags)) 966 continue; 967 list_del_init(le); 968 set_bit(XPT_CLOSE, &xprt->xpt_flags); 969 dprintk("queuing xprt %p for closing\n", xprt); 970 971 /* a thread will dequeue and close it soon */ 972 svc_xprt_enqueue(xprt); 973 } 974 spin_unlock_bh(&serv->sv_lock); 975 976 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 977 } 978 979 /* Close temporary transports whose xpt_local matches server_addr immediately 980 * instead of waiting for them to be picked up by the timer. 981 * 982 * This is meant to be called from a notifier_block that runs when an ip 983 * address is deleted. 984 */ 985 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 986 { 987 struct svc_xprt *xprt; 988 struct list_head *le, *next; 989 LIST_HEAD(to_be_closed); 990 991 spin_lock_bh(&serv->sv_lock); 992 list_for_each_safe(le, next, &serv->sv_tempsocks) { 993 xprt = list_entry(le, struct svc_xprt, xpt_list); 994 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 995 &xprt->xpt_local)) { 996 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 997 list_move(le, &to_be_closed); 998 } 999 } 1000 spin_unlock_bh(&serv->sv_lock); 1001 1002 while (!list_empty(&to_be_closed)) { 1003 le = to_be_closed.next; 1004 list_del_init(le); 1005 xprt = list_entry(le, struct svc_xprt, xpt_list); 1006 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1007 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 1008 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 1009 xprt); 1010 svc_xprt_enqueue(xprt); 1011 } 1012 } 1013 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1014 1015 static void call_xpt_users(struct svc_xprt *xprt) 1016 { 1017 struct svc_xpt_user *u; 1018 1019 spin_lock(&xprt->xpt_lock); 1020 while (!list_empty(&xprt->xpt_users)) { 1021 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1022 list_del_init(&u->list); 1023 u->callback(u); 1024 } 1025 spin_unlock(&xprt->xpt_lock); 1026 } 1027 1028 /* 1029 * Remove a dead transport 1030 */ 1031 static void svc_delete_xprt(struct svc_xprt *xprt) 1032 { 1033 struct svc_serv *serv = xprt->xpt_server; 1034 struct svc_deferred_req *dr; 1035 1036 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1037 return; 1038 1039 trace_svc_xprt_detach(xprt); 1040 xprt->xpt_ops->xpo_detach(xprt); 1041 if (xprt->xpt_bc_xprt) 1042 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1043 1044 spin_lock_bh(&serv->sv_lock); 1045 list_del_init(&xprt->xpt_list); 1046 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 1047 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1048 serv->sv_tmpcnt--; 1049 spin_unlock_bh(&serv->sv_lock); 1050 1051 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1052 kfree(dr); 1053 1054 call_xpt_users(xprt); 1055 svc_xprt_put(xprt); 1056 } 1057 1058 void svc_close_xprt(struct svc_xprt *xprt) 1059 { 1060 trace_svc_xprt_close(xprt); 1061 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1062 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1063 /* someone else will have to effect the close */ 1064 return; 1065 /* 1066 * We expect svc_close_xprt() to work even when no threads are 1067 * running (e.g., while configuring the server before starting 1068 * any threads), so if the transport isn't busy, we delete 1069 * it ourself: 1070 */ 1071 svc_delete_xprt(xprt); 1072 } 1073 EXPORT_SYMBOL_GPL(svc_close_xprt); 1074 1075 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1076 { 1077 struct svc_xprt *xprt; 1078 int ret = 0; 1079 1080 spin_lock_bh(&serv->sv_lock); 1081 list_for_each_entry(xprt, xprt_list, xpt_list) { 1082 if (xprt->xpt_net != net) 1083 continue; 1084 ret++; 1085 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1086 svc_xprt_enqueue(xprt); 1087 } 1088 spin_unlock_bh(&serv->sv_lock); 1089 return ret; 1090 } 1091 1092 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1093 { 1094 struct svc_pool *pool; 1095 struct svc_xprt *xprt; 1096 struct svc_xprt *tmp; 1097 int i; 1098 1099 for (i = 0; i < serv->sv_nrpools; i++) { 1100 pool = &serv->sv_pools[i]; 1101 1102 spin_lock_bh(&pool->sp_lock); 1103 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1104 if (xprt->xpt_net != net) 1105 continue; 1106 list_del_init(&xprt->xpt_ready); 1107 spin_unlock_bh(&pool->sp_lock); 1108 return xprt; 1109 } 1110 spin_unlock_bh(&pool->sp_lock); 1111 } 1112 return NULL; 1113 } 1114 1115 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1116 { 1117 struct svc_xprt *xprt; 1118 1119 while ((xprt = svc_dequeue_net(serv, net))) { 1120 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1121 svc_delete_xprt(xprt); 1122 } 1123 } 1124 1125 /* 1126 * Server threads may still be running (especially in the case where the 1127 * service is still running in other network namespaces). 1128 * 1129 * So we shut down sockets the same way we would on a running server, by 1130 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1131 * the close. In the case there are no such other threads, 1132 * threads running, svc_clean_up_xprts() does a simple version of a 1133 * server's main event loop, and in the case where there are other 1134 * threads, we may need to wait a little while and then check again to 1135 * see if they're done. 1136 */ 1137 void svc_close_net(struct svc_serv *serv, struct net *net) 1138 { 1139 int delay = 0; 1140 1141 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1142 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1143 1144 svc_clean_up_xprts(serv, net); 1145 msleep(delay++); 1146 } 1147 } 1148 1149 /* 1150 * Handle defer and revisit of requests 1151 */ 1152 1153 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1154 { 1155 struct svc_deferred_req *dr = 1156 container_of(dreq, struct svc_deferred_req, handle); 1157 struct svc_xprt *xprt = dr->xprt; 1158 1159 spin_lock(&xprt->xpt_lock); 1160 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1161 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1162 spin_unlock(&xprt->xpt_lock); 1163 trace_svc_defer_drop(dr); 1164 svc_xprt_put(xprt); 1165 kfree(dr); 1166 return; 1167 } 1168 dr->xprt = NULL; 1169 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1170 spin_unlock(&xprt->xpt_lock); 1171 trace_svc_defer_queue(dr); 1172 svc_xprt_enqueue(xprt); 1173 svc_xprt_put(xprt); 1174 } 1175 1176 /* 1177 * Save the request off for later processing. The request buffer looks 1178 * like this: 1179 * 1180 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1181 * 1182 * This code can only handle requests that consist of an xprt-header 1183 * and rpc-header. 1184 */ 1185 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1186 { 1187 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1188 struct svc_deferred_req *dr; 1189 1190 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1191 return NULL; /* if more than a page, give up FIXME */ 1192 if (rqstp->rq_deferred) { 1193 dr = rqstp->rq_deferred; 1194 rqstp->rq_deferred = NULL; 1195 } else { 1196 size_t skip; 1197 size_t size; 1198 /* FIXME maybe discard if size too large */ 1199 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1200 dr = kmalloc(size, GFP_KERNEL); 1201 if (dr == NULL) 1202 return NULL; 1203 1204 dr->handle.owner = rqstp->rq_server; 1205 dr->prot = rqstp->rq_prot; 1206 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1207 dr->addrlen = rqstp->rq_addrlen; 1208 dr->daddr = rqstp->rq_daddr; 1209 dr->argslen = rqstp->rq_arg.len >> 2; 1210 dr->xprt_hlen = rqstp->rq_xprt_hlen; 1211 1212 /* back up head to the start of the buffer and copy */ 1213 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1214 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1215 dr->argslen << 2); 1216 } 1217 trace_svc_defer(rqstp); 1218 svc_xprt_get(rqstp->rq_xprt); 1219 dr->xprt = rqstp->rq_xprt; 1220 set_bit(RQ_DROPME, &rqstp->rq_flags); 1221 1222 dr->handle.revisit = svc_revisit; 1223 return &dr->handle; 1224 } 1225 1226 /* 1227 * recv data from a deferred request into an active one 1228 */ 1229 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1230 { 1231 struct svc_deferred_req *dr = rqstp->rq_deferred; 1232 1233 trace_svc_defer_recv(dr); 1234 1235 /* setup iov_base past transport header */ 1236 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); 1237 /* The iov_len does not include the transport header bytes */ 1238 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; 1239 rqstp->rq_arg.page_len = 0; 1240 /* The rq_arg.len includes the transport header bytes */ 1241 rqstp->rq_arg.len = dr->argslen<<2; 1242 rqstp->rq_prot = dr->prot; 1243 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1244 rqstp->rq_addrlen = dr->addrlen; 1245 /* Save off transport header len in case we get deferred again */ 1246 rqstp->rq_xprt_hlen = dr->xprt_hlen; 1247 rqstp->rq_daddr = dr->daddr; 1248 rqstp->rq_respages = rqstp->rq_pages; 1249 svc_xprt_received(rqstp->rq_xprt); 1250 return (dr->argslen<<2) - dr->xprt_hlen; 1251 } 1252 1253 1254 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1255 { 1256 struct svc_deferred_req *dr = NULL; 1257 1258 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1259 return NULL; 1260 spin_lock(&xprt->xpt_lock); 1261 if (!list_empty(&xprt->xpt_deferred)) { 1262 dr = list_entry(xprt->xpt_deferred.next, 1263 struct svc_deferred_req, 1264 handle.recent); 1265 list_del_init(&dr->handle.recent); 1266 } else 1267 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1268 spin_unlock(&xprt->xpt_lock); 1269 return dr; 1270 } 1271 1272 /** 1273 * svc_find_xprt - find an RPC transport instance 1274 * @serv: pointer to svc_serv to search 1275 * @xcl_name: C string containing transport's class name 1276 * @net: owner net pointer 1277 * @af: Address family of transport's local address 1278 * @port: transport's IP port number 1279 * 1280 * Return the transport instance pointer for the endpoint accepting 1281 * connections/peer traffic from the specified transport class, 1282 * address family and port. 1283 * 1284 * Specifying 0 for the address family or port is effectively a 1285 * wild-card, and will result in matching the first transport in the 1286 * service's list that has a matching class name. 1287 */ 1288 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1289 struct net *net, const sa_family_t af, 1290 const unsigned short port) 1291 { 1292 struct svc_xprt *xprt; 1293 struct svc_xprt *found = NULL; 1294 1295 /* Sanity check the args */ 1296 if (serv == NULL || xcl_name == NULL) 1297 return found; 1298 1299 spin_lock_bh(&serv->sv_lock); 1300 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1301 if (xprt->xpt_net != net) 1302 continue; 1303 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1304 continue; 1305 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1306 continue; 1307 if (port != 0 && port != svc_xprt_local_port(xprt)) 1308 continue; 1309 found = xprt; 1310 svc_xprt_get(xprt); 1311 break; 1312 } 1313 spin_unlock_bh(&serv->sv_lock); 1314 return found; 1315 } 1316 EXPORT_SYMBOL_GPL(svc_find_xprt); 1317 1318 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1319 char *pos, int remaining) 1320 { 1321 int len; 1322 1323 len = snprintf(pos, remaining, "%s %u\n", 1324 xprt->xpt_class->xcl_name, 1325 svc_xprt_local_port(xprt)); 1326 if (len >= remaining) 1327 return -ENAMETOOLONG; 1328 return len; 1329 } 1330 1331 /** 1332 * svc_xprt_names - format a buffer with a list of transport names 1333 * @serv: pointer to an RPC service 1334 * @buf: pointer to a buffer to be filled in 1335 * @buflen: length of buffer to be filled in 1336 * 1337 * Fills in @buf with a string containing a list of transport names, 1338 * each name terminated with '\n'. 1339 * 1340 * Returns positive length of the filled-in string on success; otherwise 1341 * a negative errno value is returned if an error occurs. 1342 */ 1343 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1344 { 1345 struct svc_xprt *xprt; 1346 int len, totlen; 1347 char *pos; 1348 1349 /* Sanity check args */ 1350 if (!serv) 1351 return 0; 1352 1353 spin_lock_bh(&serv->sv_lock); 1354 1355 pos = buf; 1356 totlen = 0; 1357 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1358 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1359 if (len < 0) { 1360 *buf = '\0'; 1361 totlen = len; 1362 } 1363 if (len <= 0) 1364 break; 1365 1366 pos += len; 1367 totlen += len; 1368 } 1369 1370 spin_unlock_bh(&serv->sv_lock); 1371 return totlen; 1372 } 1373 EXPORT_SYMBOL_GPL(svc_xprt_names); 1374 1375 1376 /*----------------------------------------------------------------------------*/ 1377 1378 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1379 { 1380 unsigned int pidx = (unsigned int)*pos; 1381 struct svc_serv *serv = m->private; 1382 1383 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1384 1385 if (!pidx) 1386 return SEQ_START_TOKEN; 1387 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1388 } 1389 1390 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1391 { 1392 struct svc_pool *pool = p; 1393 struct svc_serv *serv = m->private; 1394 1395 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1396 1397 if (p == SEQ_START_TOKEN) { 1398 pool = &serv->sv_pools[0]; 1399 } else { 1400 unsigned int pidx = (pool - &serv->sv_pools[0]); 1401 if (pidx < serv->sv_nrpools-1) 1402 pool = &serv->sv_pools[pidx+1]; 1403 else 1404 pool = NULL; 1405 } 1406 ++*pos; 1407 return pool; 1408 } 1409 1410 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1411 { 1412 } 1413 1414 static int svc_pool_stats_show(struct seq_file *m, void *p) 1415 { 1416 struct svc_pool *pool = p; 1417 1418 if (p == SEQ_START_TOKEN) { 1419 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1420 return 0; 1421 } 1422 1423 seq_printf(m, "%u %lu %lu %lu %lu\n", 1424 pool->sp_id, 1425 (unsigned long)atomic_long_read(&pool->sp_stats.packets), 1426 pool->sp_stats.sockets_queued, 1427 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken), 1428 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout)); 1429 1430 return 0; 1431 } 1432 1433 static const struct seq_operations svc_pool_stats_seq_ops = { 1434 .start = svc_pool_stats_start, 1435 .next = svc_pool_stats_next, 1436 .stop = svc_pool_stats_stop, 1437 .show = svc_pool_stats_show, 1438 }; 1439 1440 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1441 { 1442 int err; 1443 1444 err = seq_open(file, &svc_pool_stats_seq_ops); 1445 if (!err) 1446 ((struct seq_file *) file->private_data)->private = serv; 1447 return err; 1448 } 1449 EXPORT_SYMBOL(svc_pool_stats_open); 1450 1451 /*----------------------------------------------------------------------------*/ 1452