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) | BIT(XPT_HANDSHAKE))) 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 percpu_counter_inc(&pool->sp_sockets_queued); 466 spin_lock_bh(&pool->sp_lock); 467 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); 468 spin_unlock_bh(&pool->sp_lock); 469 470 /* find a thread for this xprt */ 471 rcu_read_lock(); 472 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 473 if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) 474 continue; 475 percpu_counter_inc(&pool->sp_threads_woken); 476 rqstp->rq_qtime = ktime_get(); 477 wake_up_process(rqstp->rq_task); 478 goto out_unlock; 479 } 480 set_bit(SP_CONGESTED, &pool->sp_flags); 481 rqstp = NULL; 482 out_unlock: 483 rcu_read_unlock(); 484 trace_svc_xprt_enqueue(xprt, rqstp); 485 } 486 EXPORT_SYMBOL_GPL(svc_xprt_enqueue); 487 488 /* 489 * Dequeue the first transport, if there is one. 490 */ 491 static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) 492 { 493 struct svc_xprt *xprt = NULL; 494 495 if (list_empty(&pool->sp_sockets)) 496 goto out; 497 498 spin_lock_bh(&pool->sp_lock); 499 if (likely(!list_empty(&pool->sp_sockets))) { 500 xprt = list_first_entry(&pool->sp_sockets, 501 struct svc_xprt, xpt_ready); 502 list_del_init(&xprt->xpt_ready); 503 svc_xprt_get(xprt); 504 } 505 spin_unlock_bh(&pool->sp_lock); 506 out: 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 * Some svc_serv's will have occasional work to do, even when a xprt is not 577 * waiting to be serviced. This function is there to "kick" a task in one of 578 * those services so that it can wake up and do that work. Note that we only 579 * bother with pool 0 as we don't need to wake up more than one thread for 580 * this purpose. 581 */ 582 void svc_wake_up(struct svc_serv *serv) 583 { 584 struct svc_rqst *rqstp; 585 struct svc_pool *pool; 586 587 pool = &serv->sv_pools[0]; 588 589 rcu_read_lock(); 590 list_for_each_entry_rcu(rqstp, &pool->sp_all_threads, rq_all) { 591 /* skip any that aren't queued */ 592 if (test_bit(RQ_BUSY, &rqstp->rq_flags)) 593 continue; 594 rcu_read_unlock(); 595 wake_up_process(rqstp->rq_task); 596 trace_svc_wake_up(rqstp->rq_task->pid); 597 return; 598 } 599 rcu_read_unlock(); 600 601 /* No free entries available */ 602 set_bit(SP_TASK_PENDING, &pool->sp_flags); 603 smp_wmb(); 604 trace_svc_wake_up(0); 605 } 606 EXPORT_SYMBOL_GPL(svc_wake_up); 607 608 int svc_port_is_privileged(struct sockaddr *sin) 609 { 610 switch (sin->sa_family) { 611 case AF_INET: 612 return ntohs(((struct sockaddr_in *)sin)->sin_port) 613 < PROT_SOCK; 614 case AF_INET6: 615 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) 616 < PROT_SOCK; 617 default: 618 return 0; 619 } 620 } 621 622 /* 623 * Make sure that we don't have too many active connections. If we have, 624 * something must be dropped. It's not clear what will happen if we allow 625 * "too many" connections, but when dealing with network-facing software, 626 * we have to code defensively. Here we do that by imposing hard limits. 627 * 628 * There's no point in trying to do random drop here for DoS 629 * prevention. The NFS clients does 1 reconnect in 15 seconds. An 630 * attacker can easily beat that. 631 * 632 * The only somewhat efficient mechanism would be if drop old 633 * connections from the same IP first. But right now we don't even 634 * record the client IP in svc_sock. 635 * 636 * single-threaded services that expect a lot of clients will probably 637 * need to set sv_maxconn to override the default value which is based 638 * on the number of threads 639 */ 640 static void svc_check_conn_limits(struct svc_serv *serv) 641 { 642 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : 643 (serv->sv_nrthreads+3) * 20; 644 645 if (serv->sv_tmpcnt > limit) { 646 struct svc_xprt *xprt = NULL; 647 spin_lock_bh(&serv->sv_lock); 648 if (!list_empty(&serv->sv_tempsocks)) { 649 /* Try to help the admin */ 650 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n", 651 serv->sv_name, serv->sv_maxconn ? 652 "max number of connections" : 653 "number of threads"); 654 /* 655 * Always select the oldest connection. It's not fair, 656 * but so is life 657 */ 658 xprt = list_entry(serv->sv_tempsocks.prev, 659 struct svc_xprt, 660 xpt_list); 661 set_bit(XPT_CLOSE, &xprt->xpt_flags); 662 svc_xprt_get(xprt); 663 } 664 spin_unlock_bh(&serv->sv_lock); 665 666 if (xprt) { 667 svc_xprt_enqueue(xprt); 668 svc_xprt_put(xprt); 669 } 670 } 671 } 672 673 static int svc_alloc_arg(struct svc_rqst *rqstp) 674 { 675 struct svc_serv *serv = rqstp->rq_server; 676 struct xdr_buf *arg = &rqstp->rq_arg; 677 unsigned long pages, filled, ret; 678 679 pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT; 680 if (pages > RPCSVC_MAXPAGES) { 681 pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n", 682 pages, RPCSVC_MAXPAGES); 683 /* use as many pages as possible */ 684 pages = RPCSVC_MAXPAGES; 685 } 686 687 for (filled = 0; filled < pages; filled = ret) { 688 ret = alloc_pages_bulk_array(GFP_KERNEL, pages, 689 rqstp->rq_pages); 690 if (ret > filled) 691 /* Made progress, don't sleep yet */ 692 continue; 693 694 set_current_state(TASK_INTERRUPTIBLE); 695 if (signalled() || kthread_should_stop()) { 696 set_current_state(TASK_RUNNING); 697 return -EINTR; 698 } 699 trace_svc_alloc_arg_err(pages, ret); 700 memalloc_retry_wait(GFP_KERNEL); 701 } 702 rqstp->rq_page_end = &rqstp->rq_pages[pages]; 703 rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */ 704 705 /* Make arg->head point to first page and arg->pages point to rest */ 706 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); 707 arg->head[0].iov_len = PAGE_SIZE; 708 arg->pages = rqstp->rq_pages + 1; 709 arg->page_base = 0; 710 /* save at least one page for response */ 711 arg->page_len = (pages-2)*PAGE_SIZE; 712 arg->len = (pages-1)*PAGE_SIZE; 713 arg->tail[0].iov_len = 0; 714 715 rqstp->rq_xid = xdr_zero; 716 return 0; 717 } 718 719 static bool 720 rqst_should_sleep(struct svc_rqst *rqstp) 721 { 722 struct svc_pool *pool = rqstp->rq_pool; 723 724 /* did someone call svc_wake_up? */ 725 if (test_and_clear_bit(SP_TASK_PENDING, &pool->sp_flags)) 726 return false; 727 728 /* was a socket queued? */ 729 if (!list_empty(&pool->sp_sockets)) 730 return false; 731 732 /* are we shutting down? */ 733 if (signalled() || kthread_should_stop()) 734 return false; 735 736 /* are we freezing? */ 737 if (freezing(current)) 738 return false; 739 740 return true; 741 } 742 743 static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) 744 { 745 struct svc_pool *pool = rqstp->rq_pool; 746 long time_left = 0; 747 748 /* rq_xprt should be clear on entry */ 749 WARN_ON_ONCE(rqstp->rq_xprt); 750 751 rqstp->rq_xprt = svc_xprt_dequeue(pool); 752 if (rqstp->rq_xprt) 753 goto out_found; 754 755 /* 756 * We have to be able to interrupt this wait 757 * to bring down the daemons ... 758 */ 759 set_current_state(TASK_INTERRUPTIBLE); 760 smp_mb__before_atomic(); 761 clear_bit(SP_CONGESTED, &pool->sp_flags); 762 clear_bit(RQ_BUSY, &rqstp->rq_flags); 763 smp_mb__after_atomic(); 764 765 if (likely(rqst_should_sleep(rqstp))) 766 time_left = schedule_timeout(timeout); 767 else 768 __set_current_state(TASK_RUNNING); 769 770 try_to_freeze(); 771 772 set_bit(RQ_BUSY, &rqstp->rq_flags); 773 smp_mb__after_atomic(); 774 rqstp->rq_xprt = svc_xprt_dequeue(pool); 775 if (rqstp->rq_xprt) 776 goto out_found; 777 778 if (!time_left) 779 percpu_counter_inc(&pool->sp_threads_timedout); 780 781 if (signalled() || kthread_should_stop()) 782 return ERR_PTR(-EINTR); 783 return ERR_PTR(-EAGAIN); 784 out_found: 785 /* Normally we will wait up to 5 seconds for any required 786 * cache information to be provided. 787 */ 788 if (!test_bit(SP_CONGESTED, &pool->sp_flags)) 789 rqstp->rq_chandle.thread_wait = 5*HZ; 790 else 791 rqstp->rq_chandle.thread_wait = 1*HZ; 792 trace_svc_xprt_dequeue(rqstp); 793 return rqstp->rq_xprt; 794 } 795 796 static void svc_add_new_temp_xprt(struct svc_serv *serv, struct svc_xprt *newxpt) 797 { 798 spin_lock_bh(&serv->sv_lock); 799 set_bit(XPT_TEMP, &newxpt->xpt_flags); 800 list_add(&newxpt->xpt_list, &serv->sv_tempsocks); 801 serv->sv_tmpcnt++; 802 if (serv->sv_temptimer.function == NULL) { 803 /* setup timer to age temp transports */ 804 serv->sv_temptimer.function = svc_age_temp_xprts; 805 mod_timer(&serv->sv_temptimer, 806 jiffies + svc_conn_age_period * HZ); 807 } 808 spin_unlock_bh(&serv->sv_lock); 809 svc_xprt_received(newxpt); 810 } 811 812 static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) 813 { 814 struct svc_serv *serv = rqstp->rq_server; 815 int len = 0; 816 817 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { 818 if (test_and_clear_bit(XPT_KILL_TEMP, &xprt->xpt_flags)) 819 xprt->xpt_ops->xpo_kill_temp_xprt(xprt); 820 svc_delete_xprt(xprt); 821 /* Leave XPT_BUSY set on the dead xprt: */ 822 goto out; 823 } 824 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { 825 struct svc_xprt *newxpt; 826 /* 827 * We know this module_get will succeed because the 828 * listener holds a reference too 829 */ 830 __module_get(xprt->xpt_class->xcl_owner); 831 svc_check_conn_limits(xprt->xpt_server); 832 newxpt = xprt->xpt_ops->xpo_accept(xprt); 833 if (newxpt) { 834 newxpt->xpt_cred = get_cred(xprt->xpt_cred); 835 svc_add_new_temp_xprt(serv, newxpt); 836 trace_svc_xprt_accept(newxpt, serv->sv_name); 837 } else { 838 module_put(xprt->xpt_class->xcl_owner); 839 } 840 svc_xprt_received(xprt); 841 } else if (test_bit(XPT_HANDSHAKE, &xprt->xpt_flags)) { 842 xprt->xpt_ops->xpo_handshake(xprt); 843 svc_xprt_received(xprt); 844 } else if (svc_xprt_reserve_slot(rqstp, xprt)) { 845 /* XPT_DATA|XPT_DEFERRED case: */ 846 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", 847 rqstp, rqstp->rq_pool->sp_id, xprt, 848 kref_read(&xprt->xpt_ref)); 849 rqstp->rq_deferred = svc_deferred_dequeue(xprt); 850 if (rqstp->rq_deferred) 851 len = svc_deferred_recv(rqstp); 852 else 853 len = xprt->xpt_ops->xpo_recvfrom(rqstp); 854 rqstp->rq_stime = ktime_get(); 855 rqstp->rq_reserved = serv->sv_max_mesg; 856 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); 857 } else 858 svc_xprt_received(xprt); 859 860 out: 861 return len; 862 } 863 864 /* 865 * Receive the next request on any transport. This code is carefully 866 * organised not to touch any cachelines in the shared svc_serv 867 * structure, only cachelines in the local svc_pool. 868 */ 869 int svc_recv(struct svc_rqst *rqstp, long timeout) 870 { 871 struct svc_xprt *xprt = NULL; 872 struct svc_serv *serv = rqstp->rq_server; 873 int len, err; 874 875 err = svc_alloc_arg(rqstp); 876 if (err) 877 goto out; 878 879 try_to_freeze(); 880 cond_resched(); 881 err = -EINTR; 882 if (signalled() || kthread_should_stop()) 883 goto out; 884 885 xprt = svc_get_next_xprt(rqstp, timeout); 886 if (IS_ERR(xprt)) { 887 err = PTR_ERR(xprt); 888 goto out; 889 } 890 891 len = svc_handle_xprt(rqstp, xprt); 892 893 /* No data, incomplete (TCP) read, or accept() */ 894 err = -EAGAIN; 895 if (len <= 0) 896 goto out_release; 897 trace_svc_xdr_recvfrom(&rqstp->rq_arg); 898 899 clear_bit(XPT_OLD, &xprt->xpt_flags); 900 901 rqstp->rq_chandle.defer = svc_defer; 902 903 if (serv->sv_stats) 904 serv->sv_stats->netcnt++; 905 return len; 906 out_release: 907 rqstp->rq_res.len = 0; 908 svc_xprt_release(rqstp); 909 out: 910 return err; 911 } 912 EXPORT_SYMBOL_GPL(svc_recv); 913 914 /* 915 * Drop request 916 */ 917 void svc_drop(struct svc_rqst *rqstp) 918 { 919 trace_svc_drop(rqstp); 920 svc_xprt_release(rqstp); 921 } 922 EXPORT_SYMBOL_GPL(svc_drop); 923 924 /** 925 * svc_send - Return reply to client 926 * @rqstp: RPC transaction context 927 * 928 */ 929 void svc_send(struct svc_rqst *rqstp) 930 { 931 struct svc_xprt *xprt; 932 struct xdr_buf *xb; 933 int status; 934 935 xprt = rqstp->rq_xprt; 936 if (!xprt) 937 return; 938 939 /* calculate over-all length */ 940 xb = &rqstp->rq_res; 941 xb->len = xb->head[0].iov_len + 942 xb->page_len + 943 xb->tail[0].iov_len; 944 trace_svc_xdr_sendto(rqstp->rq_xid, xb); 945 trace_svc_stats_latency(rqstp); 946 947 status = xprt->xpt_ops->xpo_sendto(rqstp); 948 949 trace_svc_send(rqstp, status); 950 svc_xprt_release(rqstp); 951 } 952 953 /* 954 * Timer function to close old temporary transports, using 955 * a mark-and-sweep algorithm. 956 */ 957 static void svc_age_temp_xprts(struct timer_list *t) 958 { 959 struct svc_serv *serv = from_timer(serv, t, sv_temptimer); 960 struct svc_xprt *xprt; 961 struct list_head *le, *next; 962 963 dprintk("svc_age_temp_xprts\n"); 964 965 if (!spin_trylock_bh(&serv->sv_lock)) { 966 /* busy, try again 1 sec later */ 967 dprintk("svc_age_temp_xprts: busy\n"); 968 mod_timer(&serv->sv_temptimer, jiffies + HZ); 969 return; 970 } 971 972 list_for_each_safe(le, next, &serv->sv_tempsocks) { 973 xprt = list_entry(le, struct svc_xprt, xpt_list); 974 975 /* First time through, just mark it OLD. Second time 976 * through, close it. */ 977 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) 978 continue; 979 if (kref_read(&xprt->xpt_ref) > 1 || 980 test_bit(XPT_BUSY, &xprt->xpt_flags)) 981 continue; 982 list_del_init(le); 983 set_bit(XPT_CLOSE, &xprt->xpt_flags); 984 dprintk("queuing xprt %p for closing\n", xprt); 985 986 /* a thread will dequeue and close it soon */ 987 svc_xprt_enqueue(xprt); 988 } 989 spin_unlock_bh(&serv->sv_lock); 990 991 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); 992 } 993 994 /* Close temporary transports whose xpt_local matches server_addr immediately 995 * instead of waiting for them to be picked up by the timer. 996 * 997 * This is meant to be called from a notifier_block that runs when an ip 998 * address is deleted. 999 */ 1000 void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr) 1001 { 1002 struct svc_xprt *xprt; 1003 struct list_head *le, *next; 1004 LIST_HEAD(to_be_closed); 1005 1006 spin_lock_bh(&serv->sv_lock); 1007 list_for_each_safe(le, next, &serv->sv_tempsocks) { 1008 xprt = list_entry(le, struct svc_xprt, xpt_list); 1009 if (rpc_cmp_addr(server_addr, (struct sockaddr *) 1010 &xprt->xpt_local)) { 1011 dprintk("svc_age_temp_xprts_now: found %p\n", xprt); 1012 list_move(le, &to_be_closed); 1013 } 1014 } 1015 spin_unlock_bh(&serv->sv_lock); 1016 1017 while (!list_empty(&to_be_closed)) { 1018 le = to_be_closed.next; 1019 list_del_init(le); 1020 xprt = list_entry(le, struct svc_xprt, xpt_list); 1021 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1022 set_bit(XPT_KILL_TEMP, &xprt->xpt_flags); 1023 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n", 1024 xprt); 1025 svc_xprt_enqueue(xprt); 1026 } 1027 } 1028 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now); 1029 1030 static void call_xpt_users(struct svc_xprt *xprt) 1031 { 1032 struct svc_xpt_user *u; 1033 1034 spin_lock(&xprt->xpt_lock); 1035 while (!list_empty(&xprt->xpt_users)) { 1036 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list); 1037 list_del_init(&u->list); 1038 u->callback(u); 1039 } 1040 spin_unlock(&xprt->xpt_lock); 1041 } 1042 1043 /* 1044 * Remove a dead transport 1045 */ 1046 static void svc_delete_xprt(struct svc_xprt *xprt) 1047 { 1048 struct svc_serv *serv = xprt->xpt_server; 1049 struct svc_deferred_req *dr; 1050 1051 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) 1052 return; 1053 1054 trace_svc_xprt_detach(xprt); 1055 xprt->xpt_ops->xpo_detach(xprt); 1056 if (xprt->xpt_bc_xprt) 1057 xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); 1058 1059 spin_lock_bh(&serv->sv_lock); 1060 list_del_init(&xprt->xpt_list); 1061 WARN_ON_ONCE(!list_empty(&xprt->xpt_ready)); 1062 if (test_bit(XPT_TEMP, &xprt->xpt_flags)) 1063 serv->sv_tmpcnt--; 1064 spin_unlock_bh(&serv->sv_lock); 1065 1066 while ((dr = svc_deferred_dequeue(xprt)) != NULL) 1067 free_deferred(xprt, dr); 1068 1069 call_xpt_users(xprt); 1070 svc_xprt_put(xprt); 1071 } 1072 1073 /** 1074 * svc_xprt_close - Close a client connection 1075 * @xprt: transport to disconnect 1076 * 1077 */ 1078 void svc_xprt_close(struct svc_xprt *xprt) 1079 { 1080 trace_svc_xprt_close(xprt); 1081 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1082 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) 1083 /* someone else will have to effect the close */ 1084 return; 1085 /* 1086 * We expect svc_close_xprt() to work even when no threads are 1087 * running (e.g., while configuring the server before starting 1088 * any threads), so if the transport isn't busy, we delete 1089 * it ourself: 1090 */ 1091 svc_delete_xprt(xprt); 1092 } 1093 EXPORT_SYMBOL_GPL(svc_xprt_close); 1094 1095 static int svc_close_list(struct svc_serv *serv, struct list_head *xprt_list, struct net *net) 1096 { 1097 struct svc_xprt *xprt; 1098 int ret = 0; 1099 1100 spin_lock_bh(&serv->sv_lock); 1101 list_for_each_entry(xprt, xprt_list, xpt_list) { 1102 if (xprt->xpt_net != net) 1103 continue; 1104 ret++; 1105 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1106 svc_xprt_enqueue(xprt); 1107 } 1108 spin_unlock_bh(&serv->sv_lock); 1109 return ret; 1110 } 1111 1112 static struct svc_xprt *svc_dequeue_net(struct svc_serv *serv, struct net *net) 1113 { 1114 struct svc_pool *pool; 1115 struct svc_xprt *xprt; 1116 struct svc_xprt *tmp; 1117 int i; 1118 1119 for (i = 0; i < serv->sv_nrpools; i++) { 1120 pool = &serv->sv_pools[i]; 1121 1122 spin_lock_bh(&pool->sp_lock); 1123 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) { 1124 if (xprt->xpt_net != net) 1125 continue; 1126 list_del_init(&xprt->xpt_ready); 1127 spin_unlock_bh(&pool->sp_lock); 1128 return xprt; 1129 } 1130 spin_unlock_bh(&pool->sp_lock); 1131 } 1132 return NULL; 1133 } 1134 1135 static void svc_clean_up_xprts(struct svc_serv *serv, struct net *net) 1136 { 1137 struct svc_xprt *xprt; 1138 1139 while ((xprt = svc_dequeue_net(serv, net))) { 1140 set_bit(XPT_CLOSE, &xprt->xpt_flags); 1141 svc_delete_xprt(xprt); 1142 } 1143 } 1144 1145 /** 1146 * svc_xprt_destroy_all - Destroy transports associated with @serv 1147 * @serv: RPC service to be shut down 1148 * @net: target network namespace 1149 * 1150 * Server threads may still be running (especially in the case where the 1151 * service is still running in other network namespaces). 1152 * 1153 * So we shut down sockets the same way we would on a running server, by 1154 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do 1155 * the close. In the case there are no such other threads, 1156 * threads running, svc_clean_up_xprts() does a simple version of a 1157 * server's main event loop, and in the case where there are other 1158 * threads, we may need to wait a little while and then check again to 1159 * see if they're done. 1160 */ 1161 void svc_xprt_destroy_all(struct svc_serv *serv, struct net *net) 1162 { 1163 int delay = 0; 1164 1165 while (svc_close_list(serv, &serv->sv_permsocks, net) + 1166 svc_close_list(serv, &serv->sv_tempsocks, net)) { 1167 1168 svc_clean_up_xprts(serv, net); 1169 msleep(delay++); 1170 } 1171 } 1172 EXPORT_SYMBOL_GPL(svc_xprt_destroy_all); 1173 1174 /* 1175 * Handle defer and revisit of requests 1176 */ 1177 1178 static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 1179 { 1180 struct svc_deferred_req *dr = 1181 container_of(dreq, struct svc_deferred_req, handle); 1182 struct svc_xprt *xprt = dr->xprt; 1183 1184 spin_lock(&xprt->xpt_lock); 1185 set_bit(XPT_DEFERRED, &xprt->xpt_flags); 1186 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { 1187 spin_unlock(&xprt->xpt_lock); 1188 trace_svc_defer_drop(dr); 1189 free_deferred(xprt, dr); 1190 svc_xprt_put(xprt); 1191 return; 1192 } 1193 dr->xprt = NULL; 1194 list_add(&dr->handle.recent, &xprt->xpt_deferred); 1195 spin_unlock(&xprt->xpt_lock); 1196 trace_svc_defer_queue(dr); 1197 svc_xprt_enqueue(xprt); 1198 svc_xprt_put(xprt); 1199 } 1200 1201 /* 1202 * Save the request off for later processing. The request buffer looks 1203 * like this: 1204 * 1205 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> 1206 * 1207 * This code can only handle requests that consist of an xprt-header 1208 * and rpc-header. 1209 */ 1210 static struct cache_deferred_req *svc_defer(struct cache_req *req) 1211 { 1212 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); 1213 struct svc_deferred_req *dr; 1214 1215 if (rqstp->rq_arg.page_len || !test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags)) 1216 return NULL; /* if more than a page, give up FIXME */ 1217 if (rqstp->rq_deferred) { 1218 dr = rqstp->rq_deferred; 1219 rqstp->rq_deferred = NULL; 1220 } else { 1221 size_t skip; 1222 size_t size; 1223 /* FIXME maybe discard if size too large */ 1224 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; 1225 dr = kmalloc(size, GFP_KERNEL); 1226 if (dr == NULL) 1227 return NULL; 1228 1229 dr->handle.owner = rqstp->rq_server; 1230 dr->prot = rqstp->rq_prot; 1231 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); 1232 dr->addrlen = rqstp->rq_addrlen; 1233 dr->daddr = rqstp->rq_daddr; 1234 dr->argslen = rqstp->rq_arg.len >> 2; 1235 1236 /* back up head to the start of the buffer and copy */ 1237 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; 1238 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, 1239 dr->argslen << 2); 1240 } 1241 dr->xprt_ctxt = rqstp->rq_xprt_ctxt; 1242 rqstp->rq_xprt_ctxt = NULL; 1243 trace_svc_defer(rqstp); 1244 svc_xprt_get(rqstp->rq_xprt); 1245 dr->xprt = rqstp->rq_xprt; 1246 set_bit(RQ_DROPME, &rqstp->rq_flags); 1247 1248 dr->handle.revisit = svc_revisit; 1249 return &dr->handle; 1250 } 1251 1252 /* 1253 * recv data from a deferred request into an active one 1254 */ 1255 static noinline int svc_deferred_recv(struct svc_rqst *rqstp) 1256 { 1257 struct svc_deferred_req *dr = rqstp->rq_deferred; 1258 1259 trace_svc_defer_recv(dr); 1260 1261 /* setup iov_base past transport header */ 1262 rqstp->rq_arg.head[0].iov_base = dr->args; 1263 /* The iov_len does not include the transport header bytes */ 1264 rqstp->rq_arg.head[0].iov_len = dr->argslen << 2; 1265 rqstp->rq_arg.page_len = 0; 1266 /* The rq_arg.len includes the transport header bytes */ 1267 rqstp->rq_arg.len = dr->argslen << 2; 1268 rqstp->rq_prot = dr->prot; 1269 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); 1270 rqstp->rq_addrlen = dr->addrlen; 1271 /* Save off transport header len in case we get deferred again */ 1272 rqstp->rq_daddr = dr->daddr; 1273 rqstp->rq_respages = rqstp->rq_pages; 1274 rqstp->rq_xprt_ctxt = dr->xprt_ctxt; 1275 1276 dr->xprt_ctxt = NULL; 1277 svc_xprt_received(rqstp->rq_xprt); 1278 return dr->argslen << 2; 1279 } 1280 1281 1282 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 1283 { 1284 struct svc_deferred_req *dr = NULL; 1285 1286 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) 1287 return NULL; 1288 spin_lock(&xprt->xpt_lock); 1289 if (!list_empty(&xprt->xpt_deferred)) { 1290 dr = list_entry(xprt->xpt_deferred.next, 1291 struct svc_deferred_req, 1292 handle.recent); 1293 list_del_init(&dr->handle.recent); 1294 } else 1295 clear_bit(XPT_DEFERRED, &xprt->xpt_flags); 1296 spin_unlock(&xprt->xpt_lock); 1297 return dr; 1298 } 1299 1300 /** 1301 * svc_find_xprt - find an RPC transport instance 1302 * @serv: pointer to svc_serv to search 1303 * @xcl_name: C string containing transport's class name 1304 * @net: owner net pointer 1305 * @af: Address family of transport's local address 1306 * @port: transport's IP port number 1307 * 1308 * Return the transport instance pointer for the endpoint accepting 1309 * connections/peer traffic from the specified transport class, 1310 * address family and port. 1311 * 1312 * Specifying 0 for the address family or port is effectively a 1313 * wild-card, and will result in matching the first transport in the 1314 * service's list that has a matching class name. 1315 */ 1316 struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name, 1317 struct net *net, const sa_family_t af, 1318 const unsigned short port) 1319 { 1320 struct svc_xprt *xprt; 1321 struct svc_xprt *found = NULL; 1322 1323 /* Sanity check the args */ 1324 if (serv == NULL || xcl_name == NULL) 1325 return found; 1326 1327 spin_lock_bh(&serv->sv_lock); 1328 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1329 if (xprt->xpt_net != net) 1330 continue; 1331 if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) 1332 continue; 1333 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) 1334 continue; 1335 if (port != 0 && port != svc_xprt_local_port(xprt)) 1336 continue; 1337 found = xprt; 1338 svc_xprt_get(xprt); 1339 break; 1340 } 1341 spin_unlock_bh(&serv->sv_lock); 1342 return found; 1343 } 1344 EXPORT_SYMBOL_GPL(svc_find_xprt); 1345 1346 static int svc_one_xprt_name(const struct svc_xprt *xprt, 1347 char *pos, int remaining) 1348 { 1349 int len; 1350 1351 len = snprintf(pos, remaining, "%s %u\n", 1352 xprt->xpt_class->xcl_name, 1353 svc_xprt_local_port(xprt)); 1354 if (len >= remaining) 1355 return -ENAMETOOLONG; 1356 return len; 1357 } 1358 1359 /** 1360 * svc_xprt_names - format a buffer with a list of transport names 1361 * @serv: pointer to an RPC service 1362 * @buf: pointer to a buffer to be filled in 1363 * @buflen: length of buffer to be filled in 1364 * 1365 * Fills in @buf with a string containing a list of transport names, 1366 * each name terminated with '\n'. 1367 * 1368 * Returns positive length of the filled-in string on success; otherwise 1369 * a negative errno value is returned if an error occurs. 1370 */ 1371 int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen) 1372 { 1373 struct svc_xprt *xprt; 1374 int len, totlen; 1375 char *pos; 1376 1377 /* Sanity check args */ 1378 if (!serv) 1379 return 0; 1380 1381 spin_lock_bh(&serv->sv_lock); 1382 1383 pos = buf; 1384 totlen = 0; 1385 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { 1386 len = svc_one_xprt_name(xprt, pos, buflen - totlen); 1387 if (len < 0) { 1388 *buf = '\0'; 1389 totlen = len; 1390 } 1391 if (len <= 0) 1392 break; 1393 1394 pos += len; 1395 totlen += len; 1396 } 1397 1398 spin_unlock_bh(&serv->sv_lock); 1399 return totlen; 1400 } 1401 EXPORT_SYMBOL_GPL(svc_xprt_names); 1402 1403 1404 /*----------------------------------------------------------------------------*/ 1405 1406 static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 1407 { 1408 unsigned int pidx = (unsigned int)*pos; 1409 struct svc_serv *serv = m->private; 1410 1411 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx); 1412 1413 if (!pidx) 1414 return SEQ_START_TOKEN; 1415 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]); 1416 } 1417 1418 static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos) 1419 { 1420 struct svc_pool *pool = p; 1421 struct svc_serv *serv = m->private; 1422 1423 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos); 1424 1425 if (p == SEQ_START_TOKEN) { 1426 pool = &serv->sv_pools[0]; 1427 } else { 1428 unsigned int pidx = (pool - &serv->sv_pools[0]); 1429 if (pidx < serv->sv_nrpools-1) 1430 pool = &serv->sv_pools[pidx+1]; 1431 else 1432 pool = NULL; 1433 } 1434 ++*pos; 1435 return pool; 1436 } 1437 1438 static void svc_pool_stats_stop(struct seq_file *m, void *p) 1439 { 1440 } 1441 1442 static int svc_pool_stats_show(struct seq_file *m, void *p) 1443 { 1444 struct svc_pool *pool = p; 1445 1446 if (p == SEQ_START_TOKEN) { 1447 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n"); 1448 return 0; 1449 } 1450 1451 seq_printf(m, "%u %llu %llu %llu %llu\n", 1452 pool->sp_id, 1453 percpu_counter_sum_positive(&pool->sp_sockets_queued), 1454 percpu_counter_sum_positive(&pool->sp_sockets_queued), 1455 percpu_counter_sum_positive(&pool->sp_threads_woken), 1456 percpu_counter_sum_positive(&pool->sp_threads_timedout)); 1457 1458 return 0; 1459 } 1460 1461 static const struct seq_operations svc_pool_stats_seq_ops = { 1462 .start = svc_pool_stats_start, 1463 .next = svc_pool_stats_next, 1464 .stop = svc_pool_stats_stop, 1465 .show = svc_pool_stats_show, 1466 }; 1467 1468 int svc_pool_stats_open(struct svc_serv *serv, struct file *file) 1469 { 1470 int err; 1471 1472 err = seq_open(file, &svc_pool_stats_seq_ops); 1473 if (!err) 1474 ((struct seq_file *) file->private_data)->private = serv; 1475 return err; 1476 } 1477 EXPORT_SYMBOL(svc_pool_stats_open); 1478 1479 /*----------------------------------------------------------------------------*/ 1480