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/sched/mm.h> 10 #include <linux/errno.h> 11 #include <linux/freezer.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/sunrpc/bc_xprt.h> 20 #include <linux/module.h> 21 #include <linux/netdevice.h> 22 #include <trace/events/sunrpc.h> 23 24 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 25 26 static unsigned int svc_rpc_per_connection_limit __read_mostly; 27 module_param(svc_rpc_per_connection_limit, uint, 0644); 28 29 30 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); 31 static int svc_deferred_recv(struct svc_rqst *rqstp); 32 static struct cache_deferred_req *svc_defer(struct cache_req *req); 33 static void svc_age_temp_xprts(struct timer_list *t); 34 static void svc_delete_xprt(struct svc_xprt *xprt); 35 36 /* apparently the "standard" is that clients close 37 * idle connections after 5 minutes, servers after 38 * 6 minutes 39 * http://nfsv4bat.org/Documents/ConnectAThon/1996/nfstcp.pdf 40 */ 41 static int svc_conn_age_period = 6*60; 42 43 /* List of registered transport classes */ 44 static DEFINE_SPINLOCK(svc_xprt_class_lock); 45 static LIST_HEAD(svc_xprt_class_list); 46 47 /* SMP locking strategy: 48 * 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 77 /** 78 * svc_reg_xprt_class - Register a server-side RPC transport class 79 * @xcl: New transport class to be registered 80 * 81 * Returns zero on success; otherwise a negative errno is returned. 82 */ 83 int svc_reg_xprt_class(struct svc_xprt_class *xcl) 84 { 85 struct svc_xprt_class *cl; 86 int res = -EEXIST; 87 88 INIT_LIST_HEAD(&xcl->xcl_list); 89 spin_lock(&svc_xprt_class_lock); 90 /* Make sure there isn't already a class with the same name */ 91 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { 92 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) 93 goto out; 94 } 95 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); 96 res = 0; 97 out: 98 spin_unlock(&svc_xprt_class_lock); 99 return res; 100 } 101 EXPORT_SYMBOL_GPL(svc_reg_xprt_class); 102 103 /** 104 * svc_unreg_xprt_class - Unregister a server-side RPC transport class 105 * @xcl: Transport class to be unregistered 106 * 107 */ 108 void svc_unreg_xprt_class(struct svc_xprt_class *xcl) 109 { 110 spin_lock(&svc_xprt_class_lock); 111 list_del_init(&xcl->xcl_list); 112 spin_unlock(&svc_xprt_class_lock); 113 } 114 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); 115 116 /** 117 * svc_print_xprts - Format the transport list for printing 118 * @buf: target buffer for formatted address 119 * @maxlen: length of target buffer 120 * 121 * Fills in @buf with a string containing a list of transport names, each name 122 * terminated with '\n'. If the buffer is too small, some entries may be 123 * missing, but it is guaranteed that all lines in the output buffer are 124 * complete. 125 * 126 * Returns positive length of the filled-in string. 127 */ 128 int svc_print_xprts(char *buf, int maxlen) 129 { 130 struct svc_xprt_class *xcl; 131 char tmpstr[80]; 132 int len = 0; 133 buf[0] = '\0'; 134 135 spin_lock(&svc_xprt_class_lock); 136 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 137 int slen; 138 139 slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", 140 xcl->xcl_name, xcl->xcl_max_payload); 141 if (slen >= sizeof(tmpstr) || len + slen >= maxlen) 142 break; 143 len += slen; 144 strcat(buf, tmpstr); 145 } 146 spin_unlock(&svc_xprt_class_lock); 147 148 return len; 149 } 150 151 /** 152 * svc_xprt_deferred_close - Close a transport 153 * @xprt: transport instance 154 * 155 * Used in contexts that need to defer the work of shutting down 156 * the transport to an nfsd thread. 157 */ 158 void svc_xprt_deferred_close(struct svc_xprt *xprt) 159 { 160 trace_svc_xprt_close(xprt); 161 if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags)) 162 svc_xprt_enqueue(xprt); 163 } 164 EXPORT_SYMBOL_GPL(svc_xprt_deferred_close); 165 166 static void svc_xprt_free(struct kref *kref) 167 { 168 struct svc_xprt *xprt = 169 container_of(kref, struct svc_xprt, xpt_ref); 170 struct module *owner = xprt->xpt_class->xcl_owner; 171 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 172 svcauth_unix_info_release(xprt); 173 put_cred(xprt->xpt_cred); 174 put_net_track(xprt->xpt_net, &xprt->ns_tracker); 175 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 176 if (xprt->xpt_bc_xprt) 177 xprt_put(xprt->xpt_bc_xprt); 178 if (xprt->xpt_bc_xps) 179 xprt_switch_put(xprt->xpt_bc_xps); 180 trace_svc_xprt_free(xprt); 181 xprt->xpt_ops->xpo_free(xprt); 182 module_put(owner); 183 } 184 185 void svc_xprt_put(struct svc_xprt *xprt) 186 { 187 kref_put(&xprt->xpt_ref, svc_xprt_free); 188 } 189 EXPORT_SYMBOL_GPL(svc_xprt_put); 190 191 /* 192 * Called by transport drivers to initialize the transport independent 193 * portion of the transport instance. 194 */ 195 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 196 struct svc_xprt *xprt, struct svc_serv *serv) 197 { 198 memset(xprt, 0, sizeof(*xprt)); 199 xprt->xpt_class = xcl; 200 xprt->xpt_ops = xcl->xcl_ops; 201 kref_init(&xprt->xpt_ref); 202 xprt->xpt_server = serv; 203 INIT_LIST_HEAD(&xprt->xpt_list); 204 INIT_LIST_HEAD(&xprt->xpt_deferred); 205 INIT_LIST_HEAD(&xprt->xpt_users); 206 mutex_init(&xprt->xpt_mutex); 207 spin_lock_init(&xprt->xpt_lock); 208 set_bit(XPT_BUSY, &xprt->xpt_flags); 209 xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC); 210 strcpy(xprt->xpt_remotebuf, "uninitialized"); 211 } 212 EXPORT_SYMBOL_GPL(svc_xprt_init); 213 214 /** 215 * svc_xprt_received - start next receiver thread 216 * @xprt: controlling transport 217 * 218 * The caller must hold the XPT_BUSY bit and must 219 * not thereafter touch transport data. 220 * 221 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 222 * insufficient) data. 223 */ 224 void svc_xprt_received(struct svc_xprt *xprt) 225 { 226 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 227 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 228 return; 229 } 230 231 /* As soon as we clear busy, the xprt could be closed and 232 * 'put', so we need a reference to call svc_xprt_enqueue with: 233 */ 234 svc_xprt_get(xprt); 235 smp_mb__before_atomic(); 236 clear_bit(XPT_BUSY, &xprt->xpt_flags); 237 svc_xprt_enqueue(xprt); 238 svc_xprt_put(xprt); 239 } 240 EXPORT_SYMBOL_GPL(svc_xprt_received); 241 242 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 243 { 244 clear_bit(XPT_TEMP, &new->xpt_flags); 245 spin_lock_bh(&serv->sv_lock); 246 list_add(&new->xpt_list, &serv->sv_permsocks); 247 spin_unlock_bh(&serv->sv_lock); 248 svc_xprt_received(new); 249 } 250 251 static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 252 struct net *net, struct sockaddr *sap, 253 size_t len, int flags, const struct cred *cred) 254 { 255 struct svc_xprt_class *xcl; 256 257 spin_lock(&svc_xprt_class_lock); 258 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 259 struct svc_xprt *newxprt; 260 unsigned short newport; 261 262 if (strcmp(xprt_name, xcl->xcl_name)) 263 continue; 264 265 if (!try_module_get(xcl->xcl_owner)) 266 goto err; 267 268 spin_unlock(&svc_xprt_class_lock); 269 newxprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 270 if (IS_ERR(newxprt)) { 271 trace_svc_xprt_create_err(serv->sv_program->pg_name, 272 xcl->xcl_name, sap, len, 273 newxprt); 274 module_put(xcl->xcl_owner); 275 return PTR_ERR(newxprt); 276 } 277 newxprt->xpt_cred = get_cred(cred); 278 svc_add_new_perm_xprt(serv, newxprt); 279 newport = svc_xprt_local_port(newxprt); 280 return newport; 281 } 282 err: 283 spin_unlock(&svc_xprt_class_lock); 284 /* This errno is exposed to user space. Provide a reasonable 285 * perror msg for a bad transport. */ 286 return -EPROTONOSUPPORT; 287 } 288 289 /** 290 * svc_xprt_create_from_sa - Add a new listener to @serv from socket address 291 * @serv: target RPC service 292 * @xprt_name: transport class name 293 * @net: network namespace 294 * @sap: socket address pointer 295 * @flags: SVC_SOCK flags 296 * @cred: credential to bind to this transport 297 * 298 * Return local xprt port on success or %-EPROTONOSUPPORT on failure 299 */ 300 int svc_xprt_create_from_sa(struct svc_serv *serv, const char *xprt_name, 301 struct net *net, struct sockaddr *sap, 302 int flags, const struct cred *cred) 303 { 304 size_t len; 305 int err; 306 307 switch (sap->sa_family) { 308 case AF_INET: 309 len = sizeof(struct sockaddr_in); 310 break; 311 #if IS_ENABLED(CONFIG_IPV6) 312 case AF_INET6: 313 len = sizeof(struct sockaddr_in6); 314 break; 315 #endif 316 default: 317 return -EAFNOSUPPORT; 318 } 319 320 err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags, cred); 321 if (err == -EPROTONOSUPPORT) { 322 request_module("svc%s", xprt_name); 323 err = _svc_xprt_create(serv, xprt_name, net, sap, len, flags, 324 cred); 325 } 326 327 return err; 328 } 329 EXPORT_SYMBOL_GPL(svc_xprt_create_from_sa); 330 331 /** 332 * svc_xprt_create - Add a new listener to @serv 333 * @serv: target RPC service 334 * @xprt_name: transport class name 335 * @net: network namespace 336 * @family: network address family 337 * @port: listener port 338 * @flags: SVC_SOCK flags 339 * @cred: credential to bind to this transport 340 * 341 * Return local xprt port on success or %-EPROTONOSUPPORT on failure 342 */ 343 int svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 344 struct net *net, const int family, 345 const unsigned short port, int flags, 346 const struct cred *cred) 347 { 348 struct sockaddr_in sin = { 349 .sin_family = AF_INET, 350 .sin_addr.s_addr = htonl(INADDR_ANY), 351 .sin_port = htons(port), 352 }; 353 #if IS_ENABLED(CONFIG_IPV6) 354 struct sockaddr_in6 sin6 = { 355 .sin6_family = AF_INET6, 356 .sin6_addr = IN6ADDR_ANY_INIT, 357 .sin6_port = htons(port), 358 }; 359 #endif 360 struct sockaddr *sap; 361 362 switch (family) { 363 case PF_INET: 364 sap = (struct sockaddr *)&sin; 365 break; 366 #if IS_ENABLED(CONFIG_IPV6) 367 case PF_INET6: 368 sap = (struct sockaddr *)&sin6; 369 break; 370 #endif 371 default: 372 return -EAFNOSUPPORT; 373 } 374 375 return svc_xprt_create_from_sa(serv, xprt_name, net, sap, flags, cred); 376 } 377 EXPORT_SYMBOL_GPL(svc_xprt_create); 378 379 /* 380 * Copy the local and remote xprt addresses to the rqstp structure 381 */ 382 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 383 { 384 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 385 rqstp->rq_addrlen = xprt->xpt_remotelen; 386 387 /* 388 * Destination address in request is needed for binding the 389 * source address in RPC replies/callbacks later. 390 */ 391 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 392 rqstp->rq_daddrlen = xprt->xpt_locallen; 393 } 394 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 395 396 /** 397 * svc_print_addr - Format rq_addr field for printing 398 * @rqstp: svc_rqst struct containing address to print 399 * @buf: target buffer for formatted address 400 * @len: length of target buffer 401 * 402 */ 403 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 404 { 405 return __svc_print_addr(svc_addr(rqstp), buf, len); 406 } 407 EXPORT_SYMBOL_GPL(svc_print_addr); 408 409 static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) 410 { 411 unsigned int limit = svc_rpc_per_connection_limit; 412 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); 413 414 return limit == 0 || (nrqsts >= 0 && nrqsts < limit); 415 } 416 417 static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) 418 { 419 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { 420 if (!svc_xprt_slots_in_range(xprt)) 421 return false; 422 atomic_inc(&xprt->xpt_nr_rqsts); 423 set_bit(RQ_DATA, &rqstp->rq_flags); 424 } 425 return true; 426 } 427 428 static void svc_xprt_release_slot(struct svc_rqst *rqstp) 429 { 430 struct svc_xprt *xprt = rqstp->rq_xprt; 431 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { 432 atomic_dec(&xprt->xpt_nr_rqsts); 433 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 434 svc_xprt_enqueue(xprt); 435 } 436 } 437 438 static bool svc_xprt_ready(struct svc_xprt *xprt) 439 { 440 unsigned long xpt_flags; 441 442 /* 443 * If another cpu has recently updated xpt_flags, 444 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to 445 * know about it; otherwise it's possible that both that cpu and 446 * this one could call svc_xprt_enqueue() without either 447 * svc_xprt_enqueue() recognizing that the conditions below 448 * are satisfied, and we could stall indefinitely: 449 */ 450 smp_rmb(); 451 xpt_flags = READ_ONCE(xprt->xpt_flags); 452 453 trace_svc_xprt_enqueue(xprt, xpt_flags); 454 if (xpt_flags & BIT(XPT_BUSY)) 455 return false; 456 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE) | BIT(XPT_HANDSHAKE))) 457 return true; 458 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { 459 if (xprt->xpt_ops->xpo_has_wspace(xprt) && 460 svc_xprt_slots_in_range(xprt)) 461 return true; 462 trace_svc_xprt_no_write_space(xprt); 463 return false; 464 } 465 return false; 466 } 467 468 /** 469 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread 470 * @xprt: transport with data pending 471 * 472 */ 473 void svc_xprt_enqueue(struct svc_xprt *xprt) 474 { 475 struct svc_pool *pool; 476 477 if (!svc_xprt_ready(xprt)) 478 return; 479 480 /* Mark transport as busy. It will remain in this state until 481 * the provider calls svc_xprt_received. We update XPT_BUSY 482 * atomically because it also guards against trying to enqueue 483 * the transport twice. 484 */ 485 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 486 return; 487 488 pool = svc_pool_for_cpu(xprt->xpt_server); 489 490 percpu_counter_inc(&pool->sp_sockets_queued); 491 lwq_enqueue(&xprt->xpt_ready, &pool->sp_xprts); 492 493 svc_pool_wake_idle_thread(pool); 494 } 495 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 496 497 /* 498 * Dequeue the first transport, if there is one. 499 */ 500 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 501 { 502 struct svc_xprt *xprt = NULL; 503 504 xprt = lwq_dequeue(&pool->sp_xprts, struct svc_xprt, xpt_ready); 505 if (xprt) 506 svc_xprt_get(xprt); 507 return xprt; 508 } 509 510 /** 511 * svc_reserve - change the space reserved for the reply to a request. 512 * @rqstp: The request in question 513 * @space: new max space to reserve 514 * 515 * Each request reserves some space on the output queue of the transport 516 * to make sure the reply fits. This function reduces that reserved 517 * space to be the amount of space used already, plus @space. 518 * 519 */ 520 void svc_reserve(struct svc_rqst *rqstp, int space) 521 { 522 struct svc_xprt *xprt = rqstp->rq_xprt; 523 524 space += rqstp->rq_res.head[0].iov_len; 525 526 if (xprt && space < rqstp->rq_reserved) { 527 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 528 rqstp->rq_reserved = space; 529 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 530 svc_xprt_enqueue(xprt); 531 } 532 } 533 EXPORT_SYMBOL_GPL(svc_reserve); 534 535 static void free_deferred(struct svc_xprt *xprt, struct svc_deferred_req *dr) 536 { 537 if (!dr) 538 return; 539 540 xprt->xpt_ops->xpo_release_ctxt(xprt, dr->xprt_ctxt); 541 kfree(dr); 542 } 543 544 static void svc_xprt_release(struct svc_rqst *rqstp) 545 { 546 struct svc_xprt *xprt = rqstp->rq_xprt; 547 548 xprt->xpt_ops->xpo_release_ctxt(xprt, rqstp->rq_xprt_ctxt); 549 rqstp->rq_xprt_ctxt = NULL; 550 551 free_deferred(xprt, rqstp->rq_deferred); 552 rqstp->rq_deferred = NULL; 553 554 svc_rqst_release_pages(rqstp); 555 rqstp->rq_res.page_len = 0; 556 rqstp->rq_res.page_base = 0; 557 558 /* Reset response buffer and release 559 * the reservation. 560 * But first, check that enough space was reserved 561 * for the reply, otherwise we have a bug! 562 */ 563 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 564 printk(KERN_ERR "RPC request reserved %d but used %d\n", 565 rqstp->rq_reserved, 566 rqstp->rq_res.len); 567 568 rqstp->rq_res.head[0].iov_len = 0; 569 svc_reserve(rqstp, 0); 570 svc_xprt_release_slot(rqstp); 571 rqstp->rq_xprt = NULL; 572 svc_xprt_put(xprt); 573 } 574 575 /** 576 * svc_wake_up - Wake up a service thread for non-transport work 577 * @serv: RPC service 578 * 579 * Some svc_serv's will have occasional work to do, even when a xprt is not 580 * waiting to be serviced. This function is there to "kick" a task in one of 581 * those services so that it can wake up and do that work. Note that we only 582 * bother with pool 0 as we don't need to wake up more than one thread for 583 * this purpose. 584 */ 585 void svc_wake_up(struct svc_serv *serv) 586 { 587 struct svc_pool *pool = &serv->sv_pools[0]; 588 589 set_bit(SP_TASK_PENDING, &pool->sp_flags); 590 svc_pool_wake_idle_thread(pool); 591 } 592 EXPORT_SYMBOL_GPL(svc_wake_up); 593 594 int svc_port_is_privileged(struct sockaddr *sin) 595 { 596 switch (sin->sa_family) { 597 case AF_INET: 598 return ntohs(((struct sockaddr_in *)sin)->sin_port) 599 < PROT_SOCK; 600 case AF_INET6: 601 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 602 < PROT_SOCK; 603 default: 604 return 0; 605 } 606 } 607 608 /* 609 * Make sure that we don't have too many active connections. If we have, 610 * something must be dropped. It's not clear what will happen if we allow 611 * "too many" connections, but when dealing with network-facing software, 612 * we have to code defensively. Here we do that by imposing hard limits. 613 * 614 * There's no point in trying to do random drop here for DoS 615 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 616 * attacker can easily beat that. 617 * 618 * The only somewhat efficient mechanism would be if drop old 619 * connections from the same IP first. But right now we don't even 620 * record the client IP in svc_sock. 621 * 622 * single-threaded services that expect a lot of clients will probably 623 * need to set sv_maxconn to override the default value which is based 624 * on the number of threads 625 */ 626 static void svc_check_conn_limits(struct svc_serv *serv) 627 { 628 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 629 (serv->sv_nrthreads+3) * 20; 630 631 if (serv->sv_tmpcnt > limit) { 632 struct svc_xprt *xprt = NULL; 633 spin_lock_bh(&serv->sv_lock); 634 if (!list_empty(&serv->sv_tempsocks)) { 635 /* Try to help the admin */ 636 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 637 serv->sv_name, serv->sv_maxconn ? 638 "max number of connections" : 639 "number of threads"); 640 /* 641 * Always select the oldest connection. It's not fair, 642 * but so is life 643 */ 644 xprt = list_entry(serv->sv_tempsocks.prev, 645 struct svc_xprt, 646 xpt_list); 647 set_bit(XPT_CLOSE, &xprt->xpt_flags); 648 svc_xprt_get(xprt); 649 } 650 spin_unlock_bh(&serv->sv_lock); 651 652 if (xprt) { 653 svc_xprt_enqueue(xprt); 654 svc_xprt_put(xprt); 655 } 656 } 657 } 658 659 static bool svc_alloc_arg(struct svc_rqst *rqstp) 660 { 661 struct svc_serv *serv = rqstp->rq_server; 662 struct xdr_buf *arg = &rqstp->rq_arg; 663 unsigned long pages, filled, ret; 664 665 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 666 if (pages > RPCSVC_MAXPAGES) { 667 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", 668 pages, RPCSVC_MAXPAGES); 669 /* use as many pages as possible */ 670 pages = RPCSVC_MAXPAGES; 671 } 672 673 for (filled = 0; filled < pages; filled = ret) { 674 ret = alloc_pages_bulk_array(GFP_KERNEL, pages, 675 rqstp->rq_pages); 676 if (ret > filled) 677 /* Made progress, don't sleep yet */ 678 continue; 679 680 set_current_state(TASK_IDLE); 681 if (svc_thread_should_stop(rqstp)) { 682 set_current_state(TASK_RUNNING); 683 return false; 684 } 685 trace_svc_alloc_arg_err(pages, ret); 686 memalloc_retry_wait(GFP_KERNEL); 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; 700 701 rqstp->rq_xid = xdr_zero; 702 return true; 703 } 704 705 static bool 706 svc_thread_should_sleep(struct svc_rqst *rqstp) 707 { 708 struct svc_pool *pool = rqstp->rq_pool; 709 710 /* did someone call svc_wake_up? */ 711 if (test_bit(SP_TASK_PENDING, &pool->sp_flags)) 712 return false; 713 714 /* was a socket queued? */ 715 if (!lwq_empty(&pool->sp_xprts)) 716 return false; 717 718 /* are we shutting down? */ 719 if (svc_thread_should_stop(rqstp)) 720 return false; 721 722 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 723 if (svc_is_backchannel(rqstp)) { 724 if (!lwq_empty(&rqstp->rq_server->sv_cb_list)) 725 return false; 726 } 727 #endif 728 729 return true; 730 } 731 732 static void svc_thread_wait_for_work(struct svc_rqst *rqstp) 733 { 734 struct svc_pool *pool = rqstp->rq_pool; 735 736 if (svc_thread_should_sleep(rqstp)) { 737 set_current_state(TASK_IDLE | TASK_FREEZABLE); 738 llist_add(&rqstp->rq_idle, &pool->sp_idle_threads); 739 if (likely(svc_thread_should_sleep(rqstp))) 740 schedule(); 741 742 while (!llist_del_first_this(&pool->sp_idle_threads, 743 &rqstp->rq_idle)) { 744 /* Work just became available. This thread can only 745 * handle it after removing rqstp from the idle 746 * list. If that attempt failed, some other thread 747 * must have queued itself after finding no 748 * work to do, so that thread has taken responsibly 749 * for this new work. This thread can safely sleep 750 * until woken again. 751 */ 752 schedule(); 753 set_current_state(TASK_IDLE | TASK_FREEZABLE); 754 } 755 __set_current_state(TASK_RUNNING); 756 } else { 757 cond_resched(); 758 } 759 try_to_freeze(); 760 } 761 762 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 763 { 764 spin_lock_bh(&serv->sv_lock); 765 set_bit(XPT_TEMP, &newxpt->xpt_flags); 766 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 767 serv->sv_tmpcnt++; 768 if (serv->sv_temptimer.function == NULL) { 769 /* setup timer to age temp transports */ 770 serv->sv_temptimer.function = svc_age_temp_xprts; 771 mod_timer(&serv->sv_temptimer, 772 jiffies + svc_conn_age_period * HZ); 773 } 774 spin_unlock_bh(&serv->sv_lock); 775 svc_xprt_received(newxpt); 776 } 777 778 static void svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 779 { 780 struct svc_serv *serv = rqstp->rq_server; 781 int len = 0; 782 783 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 784 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 785 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 786 svc_delete_xprt(xprt); 787 /* Leave XPT_BUSY set on the dead xprt: */ 788 goto out; 789 } 790 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 791 struct svc_xprt *newxpt; 792 /* 793 * We know this module_get will succeed because the 794 * listener holds a reference too 795 */ 796 __module_get(xprt->xpt_class->xcl_owner); 797 svc_check_conn_limits(xprt->xpt_server); 798 newxpt = xprt->xpt_ops->xpo_accept(xprt); 799 if (newxpt) { 800 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 801 svc_add_new_temp_xprt(serv, newxpt); 802 trace_svc_xprt_accept(newxpt, serv->sv_name); 803 } else { 804 module_put(xprt->xpt_class->xcl_owner); 805 } 806 svc_xprt_received(xprt); 807 } else if (test_bit(XPT_HANDSHAKE, &xprt->xpt_flags)) { 808 xprt->xpt_ops->xpo_handshake(xprt); 809 svc_xprt_received(xprt); 810 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 811 /* XPT_DATA|XPT_DEFERRED case: */ 812 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 813 if (rqstp->rq_deferred) 814 len = svc_deferred_recv(rqstp); 815 else 816 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 817 rqstp->rq_reserved = serv->sv_max_mesg; 818 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 819 if (len <= 0) 820 goto out; 821 822 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 823 824 clear_bit(XPT_OLD, &xprt->xpt_flags); 825 826 rqstp->rq_chandle.defer = svc_defer; 827 828 if (serv->sv_stats) 829 serv->sv_stats->netcnt++; 830 percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived); 831 rqstp->rq_stime = ktime_get(); 832 svc_process(rqstp); 833 } else 834 svc_xprt_received(xprt); 835 836 out: 837 rqstp->rq_res.len = 0; 838 svc_xprt_release(rqstp); 839 } 840 841 static void svc_thread_wake_next(struct svc_rqst *rqstp) 842 { 843 if (!svc_thread_should_sleep(rqstp)) 844 /* More work pending after I dequeued some, 845 * wake another worker 846 */ 847 svc_pool_wake_idle_thread(rqstp->rq_pool); 848 } 849 850 /** 851 * svc_recv - Receive and process the next request on any transport 852 * @rqstp: an idle RPC service thread 853 * 854 * This code is carefully organised not to touch any cachelines in 855 * the shared svc_serv structure, only cachelines in the local 856 * svc_pool. 857 */ 858 void svc_recv(struct svc_rqst *rqstp) 859 { 860 struct svc_pool *pool = rqstp->rq_pool; 861 862 if (!svc_alloc_arg(rqstp)) 863 return; 864 865 svc_thread_wait_for_work(rqstp); 866 867 clear_bit(SP_TASK_PENDING, &pool->sp_flags); 868 869 if (svc_thread_should_stop(rqstp)) { 870 svc_thread_wake_next(rqstp); 871 return; 872 } 873 874 rqstp->rq_xprt = svc_xprt_dequeue(pool); 875 if (rqstp->rq_xprt) { 876 struct svc_xprt *xprt = rqstp->rq_xprt; 877 878 svc_thread_wake_next(rqstp); 879 /* Normally we will wait up to 5 seconds for any required 880 * cache information to be provided. When there are no 881 * idle threads, we reduce the wait time. 882 */ 883 if (pool->sp_idle_threads.first) 884 rqstp->rq_chandle.thread_wait = 5 * HZ; 885 else 886 rqstp->rq_chandle.thread_wait = 1 * HZ; 887 888 trace_svc_xprt_dequeue(rqstp); 889 svc_handle_xprt(rqstp, xprt); 890 } 891 892 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 893 if (svc_is_backchannel(rqstp)) { 894 struct svc_serv *serv = rqstp->rq_server; 895 struct rpc_rqst *req; 896 897 req = lwq_dequeue(&serv->sv_cb_list, 898 struct rpc_rqst, rq_bc_list); 899 if (req) { 900 svc_thread_wake_next(rqstp); 901 svc_process_bc(req, rqstp); 902 } 903 } 904 #endif 905 } 906 EXPORT_SYMBOL_GPL(svc_recv); 907 908 /* 909 * Drop request 910 */ 911 void svc_drop(struct svc_rqst *rqstp) 912 { 913 trace_svc_drop(rqstp); 914 } 915 EXPORT_SYMBOL_GPL(svc_drop); 916 917 /** 918 * svc_send - Return reply to client 919 * @rqstp: RPC transaction context 920 * 921 */ 922 void svc_send(struct svc_rqst *rqstp) 923 { 924 struct svc_xprt *xprt; 925 struct xdr_buf *xb; 926 int status; 927 928 xprt = rqstp->rq_xprt; 929 930 /* calculate over-all length */ 931 xb = &rqstp->rq_res; 932 xb->len = xb->head[0].iov_len + 933 xb->page_len + 934 xb->tail[0].iov_len; 935 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 936 trace_svc_stats_latency(rqstp); 937 938 status = xprt->xpt_ops->xpo_sendto(rqstp); 939 940 trace_svc_send(rqstp, status); 941 } 942 943 /* 944 * Timer function to close old temporary transports, using 945 * a mark-and-sweep algorithm. 946 */ 947 static void svc_age_temp_xprts(struct timer_list *t) 948 { 949 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 950 struct svc_xprt *xprt; 951 struct list_head *le, *next; 952 953 dprintk("svc_age_temp_xprts\n"); 954 955 if (!spin_trylock_bh(&serv->sv_lock)) { 956 /* busy, try again 1 sec later */ 957 dprintk("svc_age_temp_xprts: busy\n"); 958 mod_timer(&serv->sv_temptimer, jiffies + HZ); 959 return; 960 } 961 962 list_for_each_safe(le, next, &serv->sv_tempsocks) { 963 xprt = list_entry(le, struct svc_xprt, xpt_list); 964 965 /* First time through, just mark it OLD. Second time 966 * through, close it. */ 967 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 968 continue; 969 if (kref_read(&xprt->xpt_ref) > 1 || 970 test_bit(XPT_BUSY, &xprt->xpt_flags)) 971 continue; 972 list_del_init(le); 973 set_bit(XPT_CLOSE, &xprt->xpt_flags); 974 dprintk("queuing xprt %p for closing\n", xprt); 975 976 /* a thread will dequeue and close it soon */ 977 svc_xprt_enqueue(xprt); 978 } 979 spin_unlock_bh(&serv->sv_lock); 980 981 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 982 } 983 984 /* Close temporary transports whose xpt_local matches server_addr immediately 985 * instead of waiting for them to be picked up by the timer. 986 * 987 * This is meant to be called from a notifier_block that runs when an ip 988 * address is deleted. 989 */ 990 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 991 { 992 struct svc_xprt *xprt; 993 struct list_head *le, *next; 994 LIST_HEAD(to_be_closed); 995 996 spin_lock_bh(&serv->sv_lock); 997 list_for_each_safe(le, next, &serv->sv_tempsocks) { 998 xprt = list_entry(le, struct svc_xprt, xpt_list); 999 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 1000 &xprt->xpt_local)) { 1001 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 1002 list_move(le, &to_be_closed); 1003 } 1004 } 1005 spin_unlock_bh(&serv->sv_lock); 1006 1007 while (!list_empty(&to_be_closed)) { 1008 le = to_be_closed.next; 1009 list_del_init(le); 1010 xprt = list_entry(le, struct svc_xprt, xpt_list); 1011 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1012 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 1013 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 1014 xprt); 1015 svc_xprt_enqueue(xprt); 1016 } 1017 } 1018 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1019 1020 static void call_xpt_users(struct svc_xprt *xprt) 1021 { 1022 struct svc_xpt_user *u; 1023 1024 spin_lock(&xprt->xpt_lock); 1025 while (!list_empty(&xprt->xpt_users)) { 1026 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1027 list_del_init(&u->list); 1028 u->callback(u); 1029 } 1030 spin_unlock(&xprt->xpt_lock); 1031 } 1032 1033 /* 1034 * Remove a dead transport 1035 */ 1036 static void svc_delete_xprt(struct svc_xprt *xprt) 1037 { 1038 struct svc_serv *serv = xprt->xpt_server; 1039 struct svc_deferred_req *dr; 1040 1041 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1042 return; 1043 1044 trace_svc_xprt_detach(xprt); 1045 xprt->xpt_ops->xpo_detach(xprt); 1046 if (xprt->xpt_bc_xprt) 1047 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1048 1049 spin_lock_bh(&serv->sv_lock); 1050 list_del_init(&xprt->xpt_list); 1051 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1052 serv->sv_tmpcnt--; 1053 spin_unlock_bh(&serv->sv_lock); 1054 1055 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1056 free_deferred(xprt, dr); 1057 1058 call_xpt_users(xprt); 1059 svc_xprt_put(xprt); 1060 } 1061 1062 /** 1063 * svc_xprt_close - Close a client connection 1064 * @xprt: transport to disconnect 1065 * 1066 */ 1067 void svc_xprt_close(struct svc_xprt *xprt) 1068 { 1069 trace_svc_xprt_close(xprt); 1070 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1071 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1072 /* someone else will have to effect the close */ 1073 return; 1074 /* 1075 * We expect svc_close_xprt() to work even when no threads are 1076 * running (e.g., while configuring the server before starting 1077 * any threads), so if the transport isn't busy, we delete 1078 * it ourself: 1079 */ 1080 svc_delete_xprt(xprt); 1081 } 1082 EXPORT_SYMBOL_GPL(svc_xprt_close); 1083 1084 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1085 { 1086 struct svc_xprt *xprt; 1087 int ret = 0; 1088 1089 spin_lock_bh(&serv->sv_lock); 1090 list_for_each_entry(xprt, xprt_list, xpt_list) { 1091 if (xprt->xpt_net != net) 1092 continue; 1093 ret++; 1094 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1095 svc_xprt_enqueue(xprt); 1096 } 1097 spin_unlock_bh(&serv->sv_lock); 1098 return ret; 1099 } 1100 1101 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1102 { 1103 struct svc_xprt *xprt; 1104 int i; 1105 1106 for (i = 0; i < serv->sv_nrpools; i++) { 1107 struct svc_pool *pool = &serv->sv_pools[i]; 1108 struct llist_node *q, **t1, *t2; 1109 1110 q = lwq_dequeue_all(&pool->sp_xprts); 1111 lwq_for_each_safe(xprt, t1, t2, &q, xpt_ready) { 1112 if (xprt->xpt_net == net) { 1113 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1114 svc_delete_xprt(xprt); 1115 xprt = NULL; 1116 } 1117 } 1118 1119 if (q) 1120 lwq_enqueue_batch(q, &pool->sp_xprts); 1121 } 1122 } 1123 1124 /** 1125 * svc_xprt_destroy_all - Destroy transports associated with @serv 1126 * @serv: RPC service to be shut down 1127 * @net: target network namespace 1128 * 1129 * Server threads may still be running (especially in the case where the 1130 * service is still running in other network namespaces). 1131 * 1132 * So we shut down sockets the same way we would on a running server, by 1133 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1134 * the close. In the case there are no such other threads, 1135 * threads running, svc_clean_up_xprts() does a simple version of a 1136 * server's main event loop, and in the case where there are other 1137 * threads, we may need to wait a little while and then check again to 1138 * see if they're done. 1139 */ 1140 void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) 1141 { 1142 int delay = 0; 1143 1144 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1145 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1146 1147 svc_clean_up_xprts(serv, net); 1148 msleep(delay++); 1149 } 1150 } 1151 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); 1152 1153 /* 1154 * Handle defer and revisit of requests 1155 */ 1156 1157 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1158 { 1159 struct svc_deferred_req *dr = 1160 container_of(dreq, struct svc_deferred_req, handle); 1161 struct svc_xprt *xprt = dr->xprt; 1162 1163 spin_lock(&xprt->xpt_lock); 1164 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1165 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1166 spin_unlock(&xprt->xpt_lock); 1167 trace_svc_defer_drop(dr); 1168 free_deferred(xprt, dr); 1169 svc_xprt_put(xprt); 1170 return; 1171 } 1172 dr->xprt = NULL; 1173 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1174 spin_unlock(&xprt->xpt_lock); 1175 trace_svc_defer_queue(dr); 1176 svc_xprt_enqueue(xprt); 1177 svc_xprt_put(xprt); 1178 } 1179 1180 /* 1181 * Save the request off for later processing. The request buffer looks 1182 * like this: 1183 * 1184 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1185 * 1186 * This code can only handle requests that consist of an xprt-header 1187 * and rpc-header. 1188 */ 1189 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1190 { 1191 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1192 struct svc_deferred_req *dr; 1193 1194 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1195 return NULL; /* if more than a page, give up FIXME */ 1196 if (rqstp->rq_deferred) { 1197 dr = rqstp->rq_deferred; 1198 rqstp->rq_deferred = NULL; 1199 } else { 1200 size_t skip; 1201 size_t size; 1202 /* FIXME maybe discard if size too large */ 1203 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1204 dr = kmalloc(size, GFP_KERNEL); 1205 if (dr == NULL) 1206 return NULL; 1207 1208 dr->handle.owner = rqstp->rq_server; 1209 dr->prot = rqstp->rq_prot; 1210 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1211 dr->addrlen = rqstp->rq_addrlen; 1212 dr->daddr = rqstp->rq_daddr; 1213 dr->argslen = rqstp->rq_arg.len >> 2; 1214 1215 /* back up head to the start of the buffer and copy */ 1216 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1217 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1218 dr->argslen << 2); 1219 } 1220 dr->xprt_ctxt = rqstp->rq_xprt_ctxt; 1221 rqstp->rq_xprt_ctxt = NULL; 1222 trace_svc_defer(rqstp); 1223 svc_xprt_get(rqstp->rq_xprt); 1224 dr->xprt = rqstp->rq_xprt; 1225 set_bit(RQ_DROPME, &rqstp->rq_flags); 1226 1227 dr->handle.revisit = svc_revisit; 1228 return &dr->handle; 1229 } 1230 1231 /* 1232 * recv data from a deferred request into an active one 1233 */ 1234 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1235 { 1236 struct svc_deferred_req *dr = rqstp->rq_deferred; 1237 1238 trace_svc_defer_recv(dr); 1239 1240 /* setup iov_base past transport header */ 1241 rqstp->rq_arg.head[0].iov_base = dr->args; 1242 /* The iov_len does not include the transport header bytes */ 1243 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; 1244 rqstp->rq_arg.page_len = 0; 1245 /* The rq_arg.len includes the transport header bytes */ 1246 rqstp->rq_arg.len = dr->argslen << 2; 1247 rqstp->rq_prot = dr->prot; 1248 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1249 rqstp->rq_addrlen = dr->addrlen; 1250 /* Save off transport header len in case we get deferred again */ 1251 rqstp->rq_daddr = dr->daddr; 1252 rqstp->rq_respages = rqstp->rq_pages; 1253 rqstp->rq_xprt_ctxt = dr->xprt_ctxt; 1254 1255 dr->xprt_ctxt = NULL; 1256 svc_xprt_received(rqstp->rq_xprt); 1257 return dr->argslen << 2; 1258 } 1259 1260 1261 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1262 { 1263 struct svc_deferred_req *dr = NULL; 1264 1265 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1266 return NULL; 1267 spin_lock(&xprt->xpt_lock); 1268 if (!list_empty(&xprt->xpt_deferred)) { 1269 dr = list_entry(xprt->xpt_deferred.next, 1270 struct svc_deferred_req, 1271 handle.recent); 1272 list_del_init(&dr->handle.recent); 1273 } else 1274 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1275 spin_unlock(&xprt->xpt_lock); 1276 return dr; 1277 } 1278 1279 /** 1280 * svc_find_listener - find an RPC transport instance 1281 * @serv: pointer to svc_serv to search 1282 * @xcl_name: C string containing transport's class name 1283 * @net: owner net pointer 1284 * @sa: sockaddr containing address 1285 * 1286 * Return the transport instance pointer for the endpoint accepting 1287 * connections/peer traffic from the specified transport class, 1288 * and matching sockaddr. 1289 */ 1290 struct svc_xprt *svc_find_listener(struct svc_serv *serv, const char *xcl_name, 1291 struct net *net, const struct sockaddr *sa) 1292 { 1293 struct svc_xprt *xprt; 1294 struct svc_xprt *found = NULL; 1295 1296 spin_lock_bh(&serv->sv_lock); 1297 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1298 if (xprt->xpt_net != net) 1299 continue; 1300 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1301 continue; 1302 if (!rpc_cmp_addr_port(sa, (struct sockaddr *)&xprt->xpt_local)) 1303 continue; 1304 found = xprt; 1305 svc_xprt_get(xprt); 1306 break; 1307 } 1308 spin_unlock_bh(&serv->sv_lock); 1309 return found; 1310 } 1311 EXPORT_SYMBOL_GPL(svc_find_listener); 1312 1313 /** 1314 * svc_find_xprt - find an RPC transport instance 1315 * @serv: pointer to svc_serv to search 1316 * @xcl_name: C string containing transport's class name 1317 * @net: owner net pointer 1318 * @af: Address family of transport's local address 1319 * @port: transport's IP port number 1320 * 1321 * Return the transport instance pointer for the endpoint accepting 1322 * connections/peer traffic from the specified transport class, 1323 * address family and port. 1324 * 1325 * Specifying 0 for the address family or port is effectively a 1326 * wild-card, and will result in matching the first transport in the 1327 * service's list that has a matching class name. 1328 */ 1329 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1330 struct net *net, const sa_family_t af, 1331 const unsigned short port) 1332 { 1333 struct svc_xprt *xprt; 1334 struct svc_xprt *found = NULL; 1335 1336 /* Sanity check the args */ 1337 if (serv == NULL || xcl_name == NULL) 1338 return found; 1339 1340 spin_lock_bh(&serv->sv_lock); 1341 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1342 if (xprt->xpt_net != net) 1343 continue; 1344 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1345 continue; 1346 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1347 continue; 1348 if (port != 0 && port != svc_xprt_local_port(xprt)) 1349 continue; 1350 found = xprt; 1351 svc_xprt_get(xprt); 1352 break; 1353 } 1354 spin_unlock_bh(&serv->sv_lock); 1355 return found; 1356 } 1357 EXPORT_SYMBOL_GPL(svc_find_xprt); 1358 1359 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1360 char *pos, int remaining) 1361 { 1362 int len; 1363 1364 len = snprintf(pos, remaining, "%s %u\n", 1365 xprt->xpt_class->xcl_name, 1366 svc_xprt_local_port(xprt)); 1367 if (len >= remaining) 1368 return -ENAMETOOLONG; 1369 return len; 1370 } 1371 1372 /** 1373 * svc_xprt_names - format a buffer with a list of transport names 1374 * @serv: pointer to an RPC service 1375 * @buf: pointer to a buffer to be filled in 1376 * @buflen: length of buffer to be filled in 1377 * 1378 * Fills in @buf with a string containing a list of transport names, 1379 * each name terminated with '\n'. 1380 * 1381 * Returns positive length of the filled-in string on success; otherwise 1382 * a negative errno value is returned if an error occurs. 1383 */ 1384 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1385 { 1386 struct svc_xprt *xprt; 1387 int len, totlen; 1388 char *pos; 1389 1390 /* Sanity check args */ 1391 if (!serv) 1392 return 0; 1393 1394 spin_lock_bh(&serv->sv_lock); 1395 1396 pos = buf; 1397 totlen = 0; 1398 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1399 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1400 if (len < 0) { 1401 *buf = '\0'; 1402 totlen = len; 1403 } 1404 if (len <= 0) 1405 break; 1406 1407 pos += len; 1408 totlen += len; 1409 } 1410 1411 spin_unlock_bh(&serv->sv_lock); 1412 return totlen; 1413 } 1414 EXPORT_SYMBOL_GPL(svc_xprt_names); 1415 1416 /*----------------------------------------------------------------------------*/ 1417 1418 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1419 { 1420 unsigned int pidx = (unsigned int)*pos; 1421 struct svc_info *si = m->private; 1422 1423 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1424 1425 mutex_lock(si->mutex); 1426 1427 if (!pidx) 1428 return SEQ_START_TOKEN; 1429 if (!si->serv) 1430 return NULL; 1431 return pidx > si->serv->sv_nrpools ? NULL 1432 : &si->serv->sv_pools[pidx - 1]; 1433 } 1434 1435 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1436 { 1437 struct svc_pool *pool = p; 1438 struct svc_info *si = m->private; 1439 struct svc_serv *serv = si->serv; 1440 1441 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1442 1443 if (!serv) { 1444 pool = NULL; 1445 } else if (p == SEQ_START_TOKEN) { 1446 pool = &serv->sv_pools[0]; 1447 } else { 1448 unsigned int pidx = (pool - &serv->sv_pools[0]); 1449 if (pidx < serv->sv_nrpools-1) 1450 pool = &serv->sv_pools[pidx+1]; 1451 else 1452 pool = NULL; 1453 } 1454 ++*pos; 1455 return pool; 1456 } 1457 1458 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1459 { 1460 struct svc_info *si = m->private; 1461 1462 mutex_unlock(si->mutex); 1463 } 1464 1465 static int svc_pool_stats_show(struct seq_file *m, void *p) 1466 { 1467 struct svc_pool *pool = p; 1468 1469 if (p == SEQ_START_TOKEN) { 1470 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1471 return 0; 1472 } 1473 1474 seq_printf(m, "%u %llu %llu %llu 0\n", 1475 pool->sp_id, 1476 percpu_counter_sum_positive(&pool->sp_messages_arrived), 1477 percpu_counter_sum_positive(&pool->sp_sockets_queued), 1478 percpu_counter_sum_positive(&pool->sp_threads_woken)); 1479 1480 return 0; 1481 } 1482 1483 static const struct seq_operations svc_pool_stats_seq_ops = { 1484 .start = svc_pool_stats_start, 1485 .next = svc_pool_stats_next, 1486 .stop = svc_pool_stats_stop, 1487 .show = svc_pool_stats_show, 1488 }; 1489 1490 int svc_pool_stats_open(struct svc_info *info, struct file *file) 1491 { 1492 struct seq_file *seq; 1493 int err; 1494 1495 err = seq_open(file, &svc_pool_stats_seq_ops); 1496 if (err) 1497 return err; 1498 seq = file->private_data; 1499 seq->private = info; 1500 1501 return 0; 1502 } 1503 EXPORT_SYMBOL(svc_pool_stats_open); 1504 1505 /*----------------------------------------------------------------------------*/ 1506