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/kthread.h> 13 #include <linux/slab.h> 14 #include <net/sock.h> 15 #include <linux/sunrpc/addr.h> 16 #include <linux/sunrpc/stats.h> 17 #include <linux/sunrpc/svc_xprt.h> 18 #include <linux/sunrpc/svcsock.h> 19 #include <linux/sunrpc/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_pool->sp_lock protects most of the fields of that pool. 50 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. 51 * when both need to be taken (rare), svc_serv->sv_lock is first. 52 * The "service mutex" protects svc_serv->sv_nrthread. 53 * svc_sock->sk_lock protects the svc_sock->sk_deferred list 54 * and the ->sk_info_authunix cache. 55 * 56 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being 57 * enqueued multiply. During normal transport processing this bit 58 * is set by svc_xprt_enqueue and cleared by svc_xprt_received. 59 * Providers should not manipulate this bit directly. 60 * 61 * Some flags can be set to certain values at any time 62 * providing that certain rules are followed: 63 * 64 * XPT_CONN, XPT_DATA: 65 * - Can be set or cleared at any time. 66 * - After a set, svc_xprt_enqueue must be called to enqueue 67 * the transport for processing. 68 * - After a clear, the transport must be read/accepted. 69 * If this succeeds, it must be set again. 70 * XPT_CLOSE: 71 * - Can set at any time. It is never cleared. 72 * XPT_DEAD: 73 * - Can only be set while XPT_BUSY is held which ensures 74 * that no other thread will be using the transport or will 75 * try to set XPT_DEAD. 76 */ 77 int svc_reg_xprt_class(struct svc_xprt_class *xcl) 78 { 79 struct svc_xprt_class *cl; 80 int res = -EEXIST; 81 82 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); 83 84 INIT_LIST_HEAD(&xcl->xcl_list); 85 spin_lock(&svc_xprt_class_lock); 86 /* Make sure there isn't already a class with the same name */ 87 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { 88 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) 89 goto out; 90 } 91 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); 92 res = 0; 93 out: 94 spin_unlock(&svc_xprt_class_lock); 95 return res; 96 } 97 EXPORT_SYMBOL_GPL(svc_reg_xprt_class); 98 99 void svc_unreg_xprt_class(struct svc_xprt_class *xcl) 100 { 101 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); 102 spin_lock(&svc_xprt_class_lock); 103 list_del_init(&xcl->xcl_list); 104 spin_unlock(&svc_xprt_class_lock); 105 } 106 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); 107 108 /** 109 * svc_print_xprts - Format the transport list for printing 110 * @buf: target buffer for formatted address 111 * @maxlen: length of target buffer 112 * 113 * Fills in @buf with a string containing a list of transport names, each name 114 * terminated with '\n'. If the buffer is too small, some entries may be 115 * missing, but it is guaranteed that all lines in the output buffer are 116 * complete. 117 * 118 * Returns positive length of the filled-in string. 119 */ 120 int svc_print_xprts(char *buf, int maxlen) 121 { 122 struct svc_xprt_class *xcl; 123 char tmpstr[80]; 124 int len = 0; 125 buf[0] = '\0'; 126 127 spin_lock(&svc_xprt_class_lock); 128 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 129 int slen; 130 131 slen = snprintf(tmpstr, sizeof(tmpstr), "%s %d\n", 132 xcl->xcl_name, xcl->xcl_max_payload); 133 if (slen >= sizeof(tmpstr) || len + slen >= maxlen) 134 break; 135 len += slen; 136 strcat(buf, tmpstr); 137 } 138 spin_unlock(&svc_xprt_class_lock); 139 140 return len; 141 } 142 143 /** 144 * svc_xprt_deferred_close - Close a transport 145 * @xprt: transport instance 146 * 147 * Used in contexts that need to defer the work of shutting down 148 * the transport to an nfsd thread. 149 */ 150 void svc_xprt_deferred_close(struct svc_xprt *xprt) 151 { 152 if (!test_and_set_bit(XPT_CLOSE, &xprt->xpt_flags)) 153 svc_xprt_enqueue(xprt); 154 } 155 EXPORT_SYMBOL_GPL(svc_xprt_deferred_close); 156 157 static void svc_xprt_free(struct kref *kref) 158 { 159 struct svc_xprt *xprt = 160 container_of(kref, struct svc_xprt, xpt_ref); 161 struct module *owner = xprt->xpt_class->xcl_owner; 162 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) 163 svcauth_unix_info_release(xprt); 164 put_cred(xprt->xpt_cred); 165 put_net_track(xprt->xpt_net, &xprt->ns_tracker); 166 /* See comment on corresponding get in xs_setup_bc_tcp(): */ 167 if (xprt->xpt_bc_xprt) 168 xprt_put(xprt->xpt_bc_xprt); 169 if (xprt->xpt_bc_xps) 170 xprt_switch_put(xprt->xpt_bc_xps); 171 trace_svc_xprt_free(xprt); 172 xprt->xpt_ops->xpo_free(xprt); 173 module_put(owner); 174 } 175 176 void svc_xprt_put(struct svc_xprt *xprt) 177 { 178 kref_put(&xprt->xpt_ref, svc_xprt_free); 179 } 180 EXPORT_SYMBOL_GPL(svc_xprt_put); 181 182 /* 183 * Called by transport drivers to initialize the transport independent 184 * portion of the transport instance. 185 */ 186 void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl, 187 struct svc_xprt *xprt, struct svc_serv *serv) 188 { 189 memset(xprt, 0, sizeof(*xprt)); 190 xprt->xpt_class = xcl; 191 xprt->xpt_ops = xcl->xcl_ops; 192 kref_init(&xprt->xpt_ref); 193 xprt->xpt_server = serv; 194 INIT_LIST_HEAD(&xprt->xpt_list); 195 INIT_LIST_HEAD(&xprt->xpt_ready); 196 INIT_LIST_HEAD(&xprt->xpt_deferred); 197 INIT_LIST_HEAD(&xprt->xpt_users); 198 mutex_init(&xprt->xpt_mutex); 199 spin_lock_init(&xprt->xpt_lock); 200 set_bit(XPT_BUSY, &xprt->xpt_flags); 201 xprt->xpt_net = get_net_track(net, &xprt->ns_tracker, GFP_ATOMIC); 202 strcpy(xprt->xpt_remotebuf, "uninitialized"); 203 } 204 EXPORT_SYMBOL_GPL(svc_xprt_init); 205 206 static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, 207 struct svc_serv *serv, 208 struct net *net, 209 const int family, 210 const unsigned short port, 211 int flags) 212 { 213 struct sockaddr_in sin = { 214 .sin_family = AF_INET, 215 .sin_addr.s_addr = htonl(INADDR_ANY), 216 .sin_port = htons(port), 217 }; 218 #if IS_ENABLED(CONFIG_IPV6) 219 struct sockaddr_in6 sin6 = { 220 .sin6_family = AF_INET6, 221 .sin6_addr = IN6ADDR_ANY_INIT, 222 .sin6_port = htons(port), 223 }; 224 #endif 225 struct svc_xprt *xprt; 226 struct sockaddr *sap; 227 size_t len; 228 229 switch (family) { 230 case PF_INET: 231 sap = (struct sockaddr *)&sin; 232 len = sizeof(sin); 233 break; 234 #if IS_ENABLED(CONFIG_IPV6) 235 case PF_INET6: 236 sap = (struct sockaddr *)&sin6; 237 len = sizeof(sin6); 238 break; 239 #endif 240 default: 241 return ERR_PTR(-EAFNOSUPPORT); 242 } 243 244 xprt = xcl->xcl_ops->xpo_create(serv, net, sap, len, flags); 245 if (IS_ERR(xprt)) 246 trace_svc_xprt_create_err(serv->sv_program->pg_name, 247 xcl->xcl_name, sap, len, xprt); 248 return xprt; 249 } 250 251 /** 252 * svc_xprt_received - start next receiver thread 253 * @xprt: controlling transport 254 * 255 * The caller must hold the XPT_BUSY bit and must 256 * not thereafter touch transport data. 257 * 258 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or 259 * insufficient) data. 260 */ 261 void svc_xprt_received(struct svc_xprt *xprt) 262 { 263 if (!test_bit(XPT_BUSY, &xprt->xpt_flags)) { 264 WARN_ONCE(1, "xprt=0x%p already busy!", xprt); 265 return; 266 } 267 268 /* As soon as we clear busy, the xprt could be closed and 269 * 'put', so we need a reference to call svc_xprt_enqueue with: 270 */ 271 svc_xprt_get(xprt); 272 smp_mb__before_atomic(); 273 clear_bit(XPT_BUSY, &xprt->xpt_flags); 274 svc_xprt_enqueue(xprt); 275 svc_xprt_put(xprt); 276 } 277 EXPORT_SYMBOL_GPL(svc_xprt_received); 278 279 void svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *new) 280 { 281 clear_bit(XPT_TEMP, &new->xpt_flags); 282 spin_lock_bh(&serv->sv_lock); 283 list_add(&new->xpt_list, &serv->sv_permsocks); 284 spin_unlock_bh(&serv->sv_lock); 285 svc_xprt_received(new); 286 } 287 288 static int _svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 289 struct net *net, const int family, 290 const unsigned short port, int flags, 291 const struct cred *cred) 292 { 293 struct svc_xprt_class *xcl; 294 295 spin_lock(&svc_xprt_class_lock); 296 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { 297 struct svc_xprt *newxprt; 298 unsigned short newport; 299 300 if (strcmp(xprt_name, xcl->xcl_name)) 301 continue; 302 303 if (!try_module_get(xcl->xcl_owner)) 304 goto err; 305 306 spin_unlock(&svc_xprt_class_lock); 307 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags); 308 if (IS_ERR(newxprt)) { 309 module_put(xcl->xcl_owner); 310 return PTR_ERR(newxprt); 311 } 312 newxprt->xpt_cred = get_cred(cred); 313 svc_add_new_perm_xprt(serv, newxprt); 314 newport = svc_xprt_local_port(newxprt); 315 return newport; 316 } 317 err: 318 spin_unlock(&svc_xprt_class_lock); 319 /* This errno is exposed to user space. Provide a reasonable 320 * perror msg for a bad transport. */ 321 return -EPROTONOSUPPORT; 322 } 323 324 /** 325 * svc_xprt_create - Add a new listener to @serv 326 * @serv: target RPC service 327 * @xprt_name: transport class name 328 * @net: network namespace 329 * @family: network address family 330 * @port: listener port 331 * @flags: SVC_SOCK flags 332 * @cred: credential to bind to this transport 333 * 334 * Return values: 335 * %0: New listener added successfully 336 * %-EPROTONOSUPPORT: Requested transport type not supported 337 */ 338 int svc_xprt_create(struct svc_serv *serv, const char *xprt_name, 339 struct net *net, const int family, 340 const unsigned short port, int flags, 341 const struct cred *cred) 342 { 343 int err; 344 345 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); 346 if (err == -EPROTONOSUPPORT) { 347 request_module("svc%s", xprt_name); 348 err = _svc_xprt_create(serv, xprt_name, net, family, port, flags, cred); 349 } 350 return err; 351 } 352 EXPORT_SYMBOL_GPL(svc_xprt_create); 353 354 /* 355 * Copy the local and remote xprt addresses to the rqstp structure 356 */ 357 void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) 358 { 359 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); 360 rqstp->rq_addrlen = xprt->xpt_remotelen; 361 362 /* 363 * Destination address in request is needed for binding the 364 * source address in RPC replies/callbacks later. 365 */ 366 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen); 367 rqstp->rq_daddrlen = xprt->xpt_locallen; 368 } 369 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); 370 371 /** 372 * svc_print_addr - Format rq_addr field for printing 373 * @rqstp: svc_rqst struct containing address to print 374 * @buf: target buffer for formatted address 375 * @len: length of target buffer 376 * 377 */ 378 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) 379 { 380 return __svc_print_addr(svc_addr(rqstp), buf, len); 381 } 382 EXPORT_SYMBOL_GPL(svc_print_addr); 383 384 static bool svc_xprt_slots_in_range(struct svc_xprt *xprt) 385 { 386 unsigned int limit = svc_rpc_per_connection_limit; 387 int nrqsts = atomic_read(&xprt->xpt_nr_rqsts); 388 389 return limit == 0 || (nrqsts >= 0 && nrqsts < limit); 390 } 391 392 static bool svc_xprt_reserve_slot(struct svc_rqst *rqstp, struct svc_xprt *xprt) 393 { 394 if (!test_bit(RQ_DATA, &rqstp->rq_flags)) { 395 if (!svc_xprt_slots_in_range(xprt)) 396 return false; 397 atomic_inc(&xprt->xpt_nr_rqsts); 398 set_bit(RQ_DATA, &rqstp->rq_flags); 399 } 400 return true; 401 } 402 403 static void svc_xprt_release_slot(struct svc_rqst *rqstp) 404 { 405 struct svc_xprt *xprt = rqstp->rq_xprt; 406 if (test_and_clear_bit(RQ_DATA, &rqstp->rq_flags)) { 407 atomic_dec(&xprt->xpt_nr_rqsts); 408 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 409 svc_xprt_enqueue(xprt); 410 } 411 } 412 413 static bool svc_xprt_ready(struct svc_xprt *xprt) 414 { 415 unsigned long xpt_flags; 416 417 /* 418 * If another cpu has recently updated xpt_flags, 419 * sk_sock->flags, xpt_reserved, or xpt_nr_rqsts, we need to 420 * know about it; otherwise it's possible that both that cpu and 421 * this one could call svc_xprt_enqueue() without either 422 * svc_xprt_enqueue() recognizing that the conditions below 423 * are satisfied, and we could stall indefinitely: 424 */ 425 smp_rmb(); 426 xpt_flags = READ_ONCE(xprt->xpt_flags); 427 428 if (xpt_flags & BIT(XPT_BUSY)) 429 return false; 430 if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE))) 431 return true; 432 if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) { 433 if (xprt->xpt_ops->xpo_has_wspace(xprt) && 434 svc_xprt_slots_in_range(xprt)) 435 return true; 436 trace_svc_xprt_no_write_space(xprt); 437 return false; 438 } 439 return false; 440 } 441 442 /** 443 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread 444 * @xprt: transport with data pending 445 * 446 */ 447 void svc_xprt_enqueue(struct svc_xprt *xprt) 448 { 449 struct svc_pool *pool; 450 struct svc_rqst *rqstp = NULL; 451 452 if (!svc_xprt_ready(xprt)) 453 return; 454 455 /* Mark transport as busy. It will remain in this state until 456 * the provider calls svc_xprt_received. We update XPT_BUSY 457 * atomically because it also guards against trying to enqueue 458 * the transport twice. 459 */ 460 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 461 return; 462 463 pool = svc_pool_for_cpu(xprt->xpt_server); 464 465 atomic_long_inc(&pool->sp_stats.packets); 466 467 spin_lock_bh(&pool->sp_lock); 468 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 469 pool->sp_stats.sockets_queued++; 470 spin_unlock_bh(&pool->sp_lock); 471 472 /* find a thread for this xprt */ 473 rcu_read_lock(); 474 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 475 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) 476 continue; 477 atomic_long_inc(&pool->sp_stats.threads_woken); 478 rqstp->rq_qtime = ktime_get(); 479 wake_up_process(rqstp->rq_task); 480 goto out_unlock; 481 } 482 set_bit(SP_CONGESTED, &pool->sp_flags); 483 rqstp = NULL; 484 out_unlock: 485 rcu_read_unlock(); 486 trace_svc_xprt_enqueue(xprt, rqstp); 487 } 488 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 489 490 /* 491 * Dequeue the first transport, if there is one. 492 */ 493 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 494 { 495 struct svc_xprt *xprt = NULL; 496 497 if (list_empty(&pool->sp_sockets)) 498 goto out; 499 500 spin_lock_bh(&pool->sp_lock); 501 if (likely(!list_empty(&pool->sp_sockets))) { 502 xprt = list_first_entry(&pool->sp_sockets, 503 struct svc_xprt, xpt_ready); 504 list_del_init(&xprt->xpt_ready); 505 svc_xprt_get(xprt); 506 } 507 spin_unlock_bh(&pool->sp_lock); 508 out: 509 return xprt; 510 } 511 512 /** 513 * svc_reserve - change the space reserved for the reply to a request. 514 * @rqstp: The request in question 515 * @space: new max space to reserve 516 * 517 * Each request reserves some space on the output queue of the transport 518 * to make sure the reply fits. This function reduces that reserved 519 * space to be the amount of space used already, plus @space. 520 * 521 */ 522 void svc_reserve(struct svc_rqst *rqstp, int space) 523 { 524 struct svc_xprt *xprt = rqstp->rq_xprt; 525 526 space += rqstp->rq_res.head[0].iov_len; 527 528 if (xprt && space < rqstp->rq_reserved) { 529 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); 530 rqstp->rq_reserved = space; 531 smp_wmb(); /* See smp_rmb() in svc_xprt_ready() */ 532 svc_xprt_enqueue(xprt); 533 } 534 } 535 EXPORT_SYMBOL_GPL(svc_reserve); 536 537 static void svc_xprt_release(struct svc_rqst *rqstp) 538 { 539 struct svc_xprt *xprt = rqstp->rq_xprt; 540 541 xprt->xpt_ops->xpo_release_rqst(rqstp); 542 543 kfree(rqstp->rq_deferred); 544 rqstp->rq_deferred = NULL; 545 546 pagevec_release(&rqstp->rq_pvec); 547 svc_free_res_pages(rqstp); 548 rqstp->rq_res.page_len = 0; 549 rqstp->rq_res.page_base = 0; 550 551 /* Reset response buffer and release 552 * the reservation. 553 * But first, check that enough space was reserved 554 * for the reply, otherwise we have a bug! 555 */ 556 if ((rqstp->rq_res.len) > rqstp->rq_reserved) 557 printk(KERN_ERR "RPC request reserved %d but used %d\n", 558 rqstp->rq_reserved, 559 rqstp->rq_res.len); 560 561 rqstp->rq_res.head[0].iov_len = 0; 562 svc_reserve(rqstp, 0); 563 svc_xprt_release_slot(rqstp); 564 rqstp->rq_xprt = NULL; 565 svc_xprt_put(xprt); 566 } 567 568 /* 569 * Some svc_serv's will have occasional work to do, even when a xprt is not 570 * waiting to be serviced. This function is there to "kick" a task in one of 571 * those services so that it can wake up and do that work. Note that we only 572 * bother with pool 0 as we don't need to wake up more than one thread for 573 * this purpose. 574 */ 575 void svc_wake_up(struct svc_serv *serv) 576 { 577 struct svc_rqst *rqstp; 578 struct svc_pool *pool; 579 580 pool = &serv->sv_pools[0]; 581 582 rcu_read_lock(); 583 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 584 /* skip any that aren't queued */ 585 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 586 continue; 587 rcu_read_unlock(); 588 wake_up_process(rqstp->rq_task); 589 trace_svc_wake_up(rqstp->rq_task->pid); 590 return; 591 } 592 rcu_read_unlock(); 593 594 /* No free entries available */ 595 set_bit(SP_TASK_PENDING, &pool->sp_flags); 596 smp_wmb(); 597 trace_svc_wake_up(0); 598 } 599 EXPORT_SYMBOL_GPL(svc_wake_up); 600 601 int svc_port_is_privileged(struct sockaddr *sin) 602 { 603 switch (sin->sa_family) { 604 case AF_INET: 605 return ntohs(((struct sockaddr_in *)sin)->sin_port) 606 < PROT_SOCK; 607 case AF_INET6: 608 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 609 < PROT_SOCK; 610 default: 611 return 0; 612 } 613 } 614 615 /* 616 * Make sure that we don't have too many active connections. If we have, 617 * something must be dropped. It's not clear what will happen if we allow 618 * "too many" connections, but when dealing with network-facing software, 619 * we have to code defensively. Here we do that by imposing hard limits. 620 * 621 * There's no point in trying to do random drop here for DoS 622 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 623 * attacker can easily beat that. 624 * 625 * The only somewhat efficient mechanism would be if drop old 626 * connections from the same IP first. But right now we don't even 627 * record the client IP in svc_sock. 628 * 629 * single-threaded services that expect a lot of clients will probably 630 * need to set sv_maxconn to override the default value which is based 631 * on the number of threads 632 */ 633 static void svc_check_conn_limits(struct svc_serv *serv) 634 { 635 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 636 (serv->sv_nrthreads+3) * 20; 637 638 if (serv->sv_tmpcnt > limit) { 639 struct svc_xprt *xprt = NULL; 640 spin_lock_bh(&serv->sv_lock); 641 if (!list_empty(&serv->sv_tempsocks)) { 642 /* Try to help the admin */ 643 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 644 serv->sv_name, serv->sv_maxconn ? 645 "max number of connections" : 646 "number of threads"); 647 /* 648 * Always select the oldest connection. It's not fair, 649 * but so is life 650 */ 651 xprt = list_entry(serv->sv_tempsocks.prev, 652 struct svc_xprt, 653 xpt_list); 654 set_bit(XPT_CLOSE, &xprt->xpt_flags); 655 svc_xprt_get(xprt); 656 } 657 spin_unlock_bh(&serv->sv_lock); 658 659 if (xprt) { 660 svc_xprt_enqueue(xprt); 661 svc_xprt_put(xprt); 662 } 663 } 664 } 665 666 static int svc_alloc_arg(struct svc_rqst *rqstp) 667 { 668 struct svc_serv *serv = rqstp->rq_server; 669 struct xdr_buf *arg = &rqstp->rq_arg; 670 unsigned long pages, filled, ret; 671 672 pagevec_init(&rqstp->rq_pvec); 673 674 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 675 if (pages > RPCSVC_MAXPAGES) { 676 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", 677 pages, RPCSVC_MAXPAGES); 678 /* use as many pages as possible */ 679 pages = RPCSVC_MAXPAGES; 680 } 681 682 for (filled = 0; filled < pages; filled = ret) { 683 ret = alloc_pages_bulk_array(GFP_KERNEL, pages, 684 rqstp->rq_pages); 685 if (ret > filled) 686 /* Made progress, don't sleep yet */ 687 continue; 688 689 set_current_state(TASK_INTERRUPTIBLE); 690 if (signalled() || kthread_should_stop()) { 691 set_current_state(TASK_RUNNING); 692 return -EINTR; 693 } 694 trace_svc_alloc_arg_err(pages); 695 memalloc_retry_wait(GFP_KERNEL); 696 } 697 rqstp->rq_page_end = &rqstp->rq_pages[pages]; 698 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ 699 700 /* Make arg->head point to first page and arg->pages point to rest */ 701 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 702 arg->head[0].iov_len = PAGE_SIZE; 703 arg->pages = rqstp->rq_pages + 1; 704 arg->page_base = 0; 705 /* save at least one page for response */ 706 arg->page_len = (pages-2)*PAGE_SIZE; 707 arg->len = (pages-1)*PAGE_SIZE; 708 arg->tail[0].iov_len = 0; 709 return 0; 710 } 711 712 static bool 713 rqst_should_sleep(struct svc_rqst *rqstp) 714 { 715 struct svc_pool *pool = rqstp->rq_pool; 716 717 /* did someone call svc_wake_up? */ 718 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 719 return false; 720 721 /* was a socket queued? */ 722 if (!list_empty(&pool->sp_sockets)) 723 return false; 724 725 /* are we shutting down? */ 726 if (signalled() || kthread_should_stop()) 727 return false; 728 729 /* are we freezing? */ 730 if (freezing(current)) 731 return false; 732 733 return true; 734 } 735 736 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 737 { 738 struct svc_pool *pool = rqstp->rq_pool; 739 long time_left = 0; 740 741 /* rq_xprt should be clear on entry */ 742 WARN_ON_ONCE(rqstp->rq_xprt); 743 744 rqstp->rq_xprt = svc_xprt_dequeue(pool); 745 if (rqstp->rq_xprt) 746 goto out_found; 747 748 /* 749 * We have to be able to interrupt this wait 750 * to bring down the daemons ... 751 */ 752 set_current_state(TASK_INTERRUPTIBLE); 753 smp_mb__before_atomic(); 754 clear_bit(SP_CONGESTED, &pool->sp_flags); 755 clear_bit(RQ_BUSY, &rqstp->rq_flags); 756 smp_mb__after_atomic(); 757 758 if (likely(rqst_should_sleep(rqstp))) 759 time_left = schedule_timeout(timeout); 760 else 761 __set_current_state(TASK_RUNNING); 762 763 try_to_freeze(); 764 765 set_bit(RQ_BUSY, &rqstp->rq_flags); 766 smp_mb__after_atomic(); 767 rqstp->rq_xprt = svc_xprt_dequeue(pool); 768 if (rqstp->rq_xprt) 769 goto out_found; 770 771 if (!time_left) 772 atomic_long_inc(&pool->sp_stats.threads_timedout); 773 774 if (signalled() || kthread_should_stop()) 775 return ERR_PTR(-EINTR); 776 return ERR_PTR(-EAGAIN); 777 out_found: 778 /* Normally we will wait up to 5 seconds for any required 779 * cache information to be provided. 780 */ 781 if (!test_bit(SP_CONGESTED, &pool->sp_flags)) 782 rqstp->rq_chandle.thread_wait = 5*HZ; 783 else 784 rqstp->rq_chandle.thread_wait = 1*HZ; 785 trace_svc_xprt_dequeue(rqstp); 786 return rqstp->rq_xprt; 787 } 788 789 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 790 { 791 spin_lock_bh(&serv->sv_lock); 792 set_bit(XPT_TEMP, &newxpt->xpt_flags); 793 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 794 serv->sv_tmpcnt++; 795 if (serv->sv_temptimer.function == NULL) { 796 /* setup timer to age temp transports */ 797 serv->sv_temptimer.function = svc_age_temp_xprts; 798 mod_timer(&serv->sv_temptimer, 799 jiffies + svc_conn_age_period * HZ); 800 } 801 spin_unlock_bh(&serv->sv_lock); 802 svc_xprt_received(newxpt); 803 } 804 805 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 806 { 807 struct svc_serv *serv = rqstp->rq_server; 808 int len = 0; 809 810 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 811 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 812 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 813 svc_delete_xprt(xprt); 814 /* Leave XPT_BUSY set on the dead xprt: */ 815 goto out; 816 } 817 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 818 struct svc_xprt *newxpt; 819 /* 820 * We know this module_get will succeed because the 821 * listener holds a reference too 822 */ 823 __module_get(xprt->xpt_class->xcl_owner); 824 svc_check_conn_limits(xprt->xpt_server); 825 newxpt = xprt->xpt_ops->xpo_accept(xprt); 826 if (newxpt) { 827 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 828 svc_add_new_temp_xprt(serv, newxpt); 829 trace_svc_xprt_accept(newxpt, serv->sv_name); 830 } else { 831 module_put(xprt->xpt_class->xcl_owner); 832 } 833 svc_xprt_received(xprt); 834 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 835 /* XPT_DATA|XPT_DEFERRED case: */ 836 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 837 rqstp, rqstp->rq_pool->sp_id, xprt, 838 kref_read(&xprt->xpt_ref)); 839 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 840 if (rqstp->rq_deferred) 841 len = svc_deferred_recv(rqstp); 842 else 843 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 844 rqstp->rq_stime = ktime_get(); 845 rqstp->rq_reserved = serv->sv_max_mesg; 846 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 847 } else 848 svc_xprt_received(xprt); 849 850 out: 851 return len; 852 } 853 854 /* 855 * Receive the next request on any transport. This code is carefully 856 * organised not to touch any cachelines in the shared svc_serv 857 * structure, only cachelines in the local svc_pool. 858 */ 859 int svc_recv(struct svc_rqst *rqstp, long timeout) 860 { 861 struct svc_xprt *xprt = NULL; 862 struct svc_serv *serv = rqstp->rq_server; 863 int len, err; 864 865 err = svc_alloc_arg(rqstp); 866 if (err) 867 goto out; 868 869 try_to_freeze(); 870 cond_resched(); 871 err = -EINTR; 872 if (signalled() || kthread_should_stop()) 873 goto out; 874 875 xprt = svc_get_next_xprt(rqstp, timeout); 876 if (IS_ERR(xprt)) { 877 err = PTR_ERR(xprt); 878 goto out; 879 } 880 881 len = svc_handle_xprt(rqstp, xprt); 882 883 /* No data, incomplete (TCP) read, or accept() */ 884 err = -EAGAIN; 885 if (len <= 0) 886 goto out_release; 887 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 888 889 clear_bit(XPT_OLD, &xprt->xpt_flags); 890 891 xprt->xpt_ops->xpo_secure_port(rqstp); 892 rqstp->rq_chandle.defer = svc_defer; 893 rqstp->rq_xid = svc_getu32(&rqstp->rq_arg.head[0]); 894 895 if (serv->sv_stats) 896 serv->sv_stats->netcnt++; 897 return len; 898 out_release: 899 rqstp->rq_res.len = 0; 900 svc_xprt_release(rqstp); 901 out: 902 return err; 903 } 904 EXPORT_SYMBOL_GPL(svc_recv); 905 906 /* 907 * Drop request 908 */ 909 void svc_drop(struct svc_rqst *rqstp) 910 { 911 trace_svc_drop(rqstp); 912 svc_xprt_release(rqstp); 913 } 914 EXPORT_SYMBOL_GPL(svc_drop); 915 916 /* 917 * Return reply to client. 918 */ 919 int svc_send(struct svc_rqst *rqstp) 920 { 921 struct svc_xprt *xprt; 922 int len = -EFAULT; 923 struct xdr_buf *xb; 924 925 xprt = rqstp->rq_xprt; 926 if (!xprt) 927 goto out; 928 929 /* calculate over-all length */ 930 xb = &rqstp->rq_res; 931 xb->len = xb->head[0].iov_len + 932 xb->page_len + 933 xb->tail[0].iov_len; 934 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 935 trace_svc_stats_latency(rqstp); 936 937 len = xprt->xpt_ops->xpo_sendto(rqstp); 938 939 trace_svc_send(rqstp, len); 940 svc_xprt_release(rqstp); 941 942 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) 943 len = 0; 944 out: 945 return len; 946 } 947 948 /* 949 * Timer function to close old temporary transports, using 950 * a mark-and-sweep algorithm. 951 */ 952 static void svc_age_temp_xprts(struct timer_list *t) 953 { 954 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 955 struct svc_xprt *xprt; 956 struct list_head *le, *next; 957 958 dprintk("svc_age_temp_xprts\n"); 959 960 if (!spin_trylock_bh(&serv->sv_lock)) { 961 /* busy, try again 1 sec later */ 962 dprintk("svc_age_temp_xprts: busy\n"); 963 mod_timer(&serv->sv_temptimer, jiffies + HZ); 964 return; 965 } 966 967 list_for_each_safe(le, next, &serv->sv_tempsocks) { 968 xprt = list_entry(le, struct svc_xprt, xpt_list); 969 970 /* First time through, just mark it OLD. Second time 971 * through, close it. */ 972 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 973 continue; 974 if (kref_read(&xprt->xpt_ref) > 1 || 975 test_bit(XPT_BUSY, &xprt->xpt_flags)) 976 continue; 977 list_del_init(le); 978 set_bit(XPT_CLOSE, &xprt->xpt_flags); 979 dprintk("queuing xprt %p for closing\n", xprt); 980 981 /* a thread will dequeue and close it soon */ 982 svc_xprt_enqueue(xprt); 983 } 984 spin_unlock_bh(&serv->sv_lock); 985 986 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 987 } 988 989 /* Close temporary transports whose xpt_local matches server_addr immediately 990 * instead of waiting for them to be picked up by the timer. 991 * 992 * This is meant to be called from a notifier_block that runs when an ip 993 * address is deleted. 994 */ 995 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 996 { 997 struct svc_xprt *xprt; 998 struct list_head *le, *next; 999 LIST_HEAD(to_be_closed); 1000 1001 spin_lock_bh(&serv->sv_lock); 1002 list_for_each_safe(le, next, &serv->sv_tempsocks) { 1003 xprt = list_entry(le, struct svc_xprt, xpt_list); 1004 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 1005 &xprt->xpt_local)) { 1006 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 1007 list_move(le, &to_be_closed); 1008 } 1009 } 1010 spin_unlock_bh(&serv->sv_lock); 1011 1012 while (!list_empty(&to_be_closed)) { 1013 le = to_be_closed.next; 1014 list_del_init(le); 1015 xprt = list_entry(le, struct svc_xprt, xpt_list); 1016 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1017 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 1018 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 1019 xprt); 1020 svc_xprt_enqueue(xprt); 1021 } 1022 } 1023 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1024 1025 static void call_xpt_users(struct svc_xprt *xprt) 1026 { 1027 struct svc_xpt_user *u; 1028 1029 spin_lock(&xprt->xpt_lock); 1030 while (!list_empty(&xprt->xpt_users)) { 1031 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1032 list_del_init(&u->list); 1033 u->callback(u); 1034 } 1035 spin_unlock(&xprt->xpt_lock); 1036 } 1037 1038 /* 1039 * Remove a dead transport 1040 */ 1041 static void svc_delete_xprt(struct svc_xprt *xprt) 1042 { 1043 struct svc_serv *serv = xprt->xpt_server; 1044 struct svc_deferred_req *dr; 1045 1046 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1047 return; 1048 1049 trace_svc_xprt_detach(xprt); 1050 xprt->xpt_ops->xpo_detach(xprt); 1051 if (xprt->xpt_bc_xprt) 1052 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1053 1054 spin_lock_bh(&serv->sv_lock); 1055 list_del_init(&xprt->xpt_list); 1056 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 1057 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1058 serv->sv_tmpcnt--; 1059 spin_unlock_bh(&serv->sv_lock); 1060 1061 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1062 kfree(dr); 1063 1064 call_xpt_users(xprt); 1065 svc_xprt_put(xprt); 1066 } 1067 1068 /** 1069 * svc_xprt_close - Close a client connection 1070 * @xprt: transport to disconnect 1071 * 1072 */ 1073 void svc_xprt_close(struct svc_xprt *xprt) 1074 { 1075 trace_svc_xprt_close(xprt); 1076 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1077 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1078 /* someone else will have to effect the close */ 1079 return; 1080 /* 1081 * We expect svc_close_xprt() to work even when no threads are 1082 * running (e.g., while configuring the server before starting 1083 * any threads), so if the transport isn't busy, we delete 1084 * it ourself: 1085 */ 1086 svc_delete_xprt(xprt); 1087 } 1088 EXPORT_SYMBOL_GPL(svc_xprt_close); 1089 1090 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1091 { 1092 struct svc_xprt *xprt; 1093 int ret = 0; 1094 1095 spin_lock_bh(&serv->sv_lock); 1096 list_for_each_entry(xprt, xprt_list, xpt_list) { 1097 if (xprt->xpt_net != net) 1098 continue; 1099 ret++; 1100 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1101 svc_xprt_enqueue(xprt); 1102 } 1103 spin_unlock_bh(&serv->sv_lock); 1104 return ret; 1105 } 1106 1107 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1108 { 1109 struct svc_pool *pool; 1110 struct svc_xprt *xprt; 1111 struct svc_xprt *tmp; 1112 int i; 1113 1114 for (i = 0; i < serv->sv_nrpools; i++) { 1115 pool = &serv->sv_pools[i]; 1116 1117 spin_lock_bh(&pool->sp_lock); 1118 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1119 if (xprt->xpt_net != net) 1120 continue; 1121 list_del_init(&xprt->xpt_ready); 1122 spin_unlock_bh(&pool->sp_lock); 1123 return xprt; 1124 } 1125 spin_unlock_bh(&pool->sp_lock); 1126 } 1127 return NULL; 1128 } 1129 1130 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1131 { 1132 struct svc_xprt *xprt; 1133 1134 while ((xprt = svc_dequeue_net(serv, net))) { 1135 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1136 svc_delete_xprt(xprt); 1137 } 1138 } 1139 1140 /** 1141 * svc_xprt_destroy_all - Destroy transports associated with @serv 1142 * @serv: RPC service to be shut down 1143 * @net: target network namespace 1144 * 1145 * Server threads may still be running (especially in the case where the 1146 * service is still running in other network namespaces). 1147 * 1148 * So we shut down sockets the same way we would on a running server, by 1149 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1150 * the close. In the case there are no such other threads, 1151 * threads running, svc_clean_up_xprts() does a simple version of a 1152 * server's main event loop, and in the case where there are other 1153 * threads, we may need to wait a little while and then check again to 1154 * see if they're done. 1155 */ 1156 void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) 1157 { 1158 int delay = 0; 1159 1160 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1161 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1162 1163 svc_clean_up_xprts(serv, net); 1164 msleep(delay++); 1165 } 1166 } 1167 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); 1168 1169 /* 1170 * Handle defer and revisit of requests 1171 */ 1172 1173 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1174 { 1175 struct svc_deferred_req *dr = 1176 container_of(dreq, struct svc_deferred_req, handle); 1177 struct svc_xprt *xprt = dr->xprt; 1178 1179 spin_lock(&xprt->xpt_lock); 1180 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1181 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1182 spin_unlock(&xprt->xpt_lock); 1183 trace_svc_defer_drop(dr); 1184 svc_xprt_put(xprt); 1185 kfree(dr); 1186 return; 1187 } 1188 dr->xprt = NULL; 1189 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1190 spin_unlock(&xprt->xpt_lock); 1191 trace_svc_defer_queue(dr); 1192 svc_xprt_enqueue(xprt); 1193 svc_xprt_put(xprt); 1194 } 1195 1196 /* 1197 * Save the request off for later processing. The request buffer looks 1198 * like this: 1199 * 1200 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1201 * 1202 * This code can only handle requests that consist of an xprt-header 1203 * and rpc-header. 1204 */ 1205 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1206 { 1207 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1208 struct svc_deferred_req *dr; 1209 1210 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1211 return NULL; /* if more than a page, give up FIXME */ 1212 if (rqstp->rq_deferred) { 1213 dr = rqstp->rq_deferred; 1214 rqstp->rq_deferred = NULL; 1215 } else { 1216 size_t skip; 1217 size_t size; 1218 /* FIXME maybe discard if size too large */ 1219 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1220 dr = kmalloc(size, GFP_KERNEL); 1221 if (dr == NULL) 1222 return NULL; 1223 1224 dr->handle.owner = rqstp->rq_server; 1225 dr->prot = rqstp->rq_prot; 1226 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1227 dr->addrlen = rqstp->rq_addrlen; 1228 dr->daddr = rqstp->rq_daddr; 1229 dr->argslen = rqstp->rq_arg.len >> 2; 1230 dr->xprt_ctxt = rqstp->rq_xprt_ctxt; 1231 rqstp->rq_xprt_ctxt = NULL; 1232 1233 /* back up head to the start of the buffer and copy */ 1234 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1235 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1236 dr->argslen << 2); 1237 } 1238 trace_svc_defer(rqstp); 1239 svc_xprt_get(rqstp->rq_xprt); 1240 dr->xprt = rqstp->rq_xprt; 1241 __set_bit(RQ_DROPME, &rqstp->rq_flags); 1242 1243 dr->handle.revisit = svc_revisit; 1244 return &dr->handle; 1245 } 1246 1247 /* 1248 * recv data from a deferred request into an active one 1249 */ 1250 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1251 { 1252 struct svc_deferred_req *dr = rqstp->rq_deferred; 1253 1254 trace_svc_defer_recv(dr); 1255 1256 /* setup iov_base past transport header */ 1257 rqstp->rq_arg.head[0].iov_base = dr->args; 1258 /* The iov_len does not include the transport header bytes */ 1259 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; 1260 rqstp->rq_arg.page_len = 0; 1261 /* The rq_arg.len includes the transport header bytes */ 1262 rqstp->rq_arg.len = dr->argslen << 2; 1263 rqstp->rq_prot = dr->prot; 1264 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1265 rqstp->rq_addrlen = dr->addrlen; 1266 /* Save off transport header len in case we get deferred again */ 1267 rqstp->rq_daddr = dr->daddr; 1268 rqstp->rq_respages = rqstp->rq_pages; 1269 rqstp->rq_xprt_ctxt = dr->xprt_ctxt; 1270 svc_xprt_received(rqstp->rq_xprt); 1271 return dr->argslen << 2; 1272 } 1273 1274 1275 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1276 { 1277 struct svc_deferred_req *dr = NULL; 1278 1279 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1280 return NULL; 1281 spin_lock(&xprt->xpt_lock); 1282 if (!list_empty(&xprt->xpt_deferred)) { 1283 dr = list_entry(xprt->xpt_deferred.next, 1284 struct svc_deferred_req, 1285 handle.recent); 1286 list_del_init(&dr->handle.recent); 1287 } else 1288 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1289 spin_unlock(&xprt->xpt_lock); 1290 return dr; 1291 } 1292 1293 /** 1294 * svc_find_xprt - find an RPC transport instance 1295 * @serv: pointer to svc_serv to search 1296 * @xcl_name: C string containing transport's class name 1297 * @net: owner net pointer 1298 * @af: Address family of transport's local address 1299 * @port: transport's IP port number 1300 * 1301 * Return the transport instance pointer for the endpoint accepting 1302 * connections/peer traffic from the specified transport class, 1303 * address family and port. 1304 * 1305 * Specifying 0 for the address family or port is effectively a 1306 * wild-card, and will result in matching the first transport in the 1307 * service's list that has a matching class name. 1308 */ 1309 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1310 struct net *net, const sa_family_t af, 1311 const unsigned short port) 1312 { 1313 struct svc_xprt *xprt; 1314 struct svc_xprt *found = NULL; 1315 1316 /* Sanity check the args */ 1317 if (serv == NULL || xcl_name == NULL) 1318 return found; 1319 1320 spin_lock_bh(&serv->sv_lock); 1321 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1322 if (xprt->xpt_net != net) 1323 continue; 1324 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1325 continue; 1326 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1327 continue; 1328 if (port != 0 && port != svc_xprt_local_port(xprt)) 1329 continue; 1330 found = xprt; 1331 svc_xprt_get(xprt); 1332 break; 1333 } 1334 spin_unlock_bh(&serv->sv_lock); 1335 return found; 1336 } 1337 EXPORT_SYMBOL_GPL(svc_find_xprt); 1338 1339 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1340 char *pos, int remaining) 1341 { 1342 int len; 1343 1344 len = snprintf(pos, remaining, "%s %u\n", 1345 xprt->xpt_class->xcl_name, 1346 svc_xprt_local_port(xprt)); 1347 if (len >= remaining) 1348 return -ENAMETOOLONG; 1349 return len; 1350 } 1351 1352 /** 1353 * svc_xprt_names - format a buffer with a list of transport names 1354 * @serv: pointer to an RPC service 1355 * @buf: pointer to a buffer to be filled in 1356 * @buflen: length of buffer to be filled in 1357 * 1358 * Fills in @buf with a string containing a list of transport names, 1359 * each name terminated with '\n'. 1360 * 1361 * Returns positive length of the filled-in string on success; otherwise 1362 * a negative errno value is returned if an error occurs. 1363 */ 1364 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1365 { 1366 struct svc_xprt *xprt; 1367 int len, totlen; 1368 char *pos; 1369 1370 /* Sanity check args */ 1371 if (!serv) 1372 return 0; 1373 1374 spin_lock_bh(&serv->sv_lock); 1375 1376 pos = buf; 1377 totlen = 0; 1378 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1379 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1380 if (len < 0) { 1381 *buf = '\0'; 1382 totlen = len; 1383 } 1384 if (len <= 0) 1385 break; 1386 1387 pos += len; 1388 totlen += len; 1389 } 1390 1391 spin_unlock_bh(&serv->sv_lock); 1392 return totlen; 1393 } 1394 EXPORT_SYMBOL_GPL(svc_xprt_names); 1395 1396 1397 /*----------------------------------------------------------------------------*/ 1398 1399 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1400 { 1401 unsigned int pidx = (unsigned int)*pos; 1402 struct svc_serv *serv = m->private; 1403 1404 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1405 1406 if (!pidx) 1407 return SEQ_START_TOKEN; 1408 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1409 } 1410 1411 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1412 { 1413 struct svc_pool *pool = p; 1414 struct svc_serv *serv = m->private; 1415 1416 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1417 1418 if (p == SEQ_START_TOKEN) { 1419 pool = &serv->sv_pools[0]; 1420 } else { 1421 unsigned int pidx = (pool - &serv->sv_pools[0]); 1422 if (pidx < serv->sv_nrpools-1) 1423 pool = &serv->sv_pools[pidx+1]; 1424 else 1425 pool = NULL; 1426 } 1427 ++*pos; 1428 return pool; 1429 } 1430 1431 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1432 { 1433 } 1434 1435 static int svc_pool_stats_show(struct seq_file *m, void *p) 1436 { 1437 struct svc_pool *pool = p; 1438 1439 if (p == SEQ_START_TOKEN) { 1440 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1441 return 0; 1442 } 1443 1444 seq_printf(m, "%u %lu %lu %lu %lu\n", 1445 pool->sp_id, 1446 (unsigned long)atomic_long_read(&pool->sp_stats.packets), 1447 pool->sp_stats.sockets_queued, 1448 (unsigned long)atomic_long_read(&pool->sp_stats.threads_woken), 1449 (unsigned long)atomic_long_read(&pool->sp_stats.threads_timedout)); 1450 1451 return 0; 1452 } 1453 1454 static const struct seq_operations svc_pool_stats_seq_ops = { 1455 .start = svc_pool_stats_start, 1456 .next = svc_pool_stats_next, 1457 .stop = svc_pool_stats_stop, 1458 .show = svc_pool_stats_show, 1459 }; 1460 1461 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1462 { 1463 int err; 1464 1465 err = seq_open(file, &svc_pool_stats_seq_ops); 1466 if (!err) 1467 ((struct seq_file *) file->private_data)->private = serv; 1468 return err; 1469 } 1470 EXPORT_SYMBOL(svc_pool_stats_open); 1471 1472 /*----------------------------------------------------------------------------*/ 1473