1 /* 2 * linux/fs/lockd/svc.c 3 * 4 * This is the central lockd service. 5 * 6 * FIXME: Separate the lockd NFS server functionality from the lockd NFS 7 * client functionality. Oh why didn't Sun create two separate 8 * services in the first place? 9 * 10 * Authors: Olaf Kirch (okir@monad.swb.de) 11 * 12 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> 13 */ 14 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/sysctl.h> 18 #include <linux/moduleparam.h> 19 20 #include <linux/sched.h> 21 #include <linux/errno.h> 22 #include <linux/in.h> 23 #include <linux/uio.h> 24 #include <linux/slab.h> 25 #include <linux/smp.h> 26 #include <linux/smp_lock.h> 27 #include <linux/mutex.h> 28 #include <linux/kthread.h> 29 #include <linux/freezer.h> 30 31 #include <linux/sunrpc/types.h> 32 #include <linux/sunrpc/stats.h> 33 #include <linux/sunrpc/clnt.h> 34 #include <linux/sunrpc/svc.h> 35 #include <linux/sunrpc/svcsock.h> 36 #include <net/ip.h> 37 #include <linux/lockd/lockd.h> 38 #include <linux/lockd/sm_inter.h> 39 #include <linux/nfs.h> 40 41 #define NLMDBG_FACILITY NLMDBG_SVC 42 #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) 43 #define ALLOWED_SIGS (sigmask(SIGKILL)) 44 45 static struct svc_program nlmsvc_program; 46 47 struct nlmsvc_binding * nlmsvc_ops; 48 EXPORT_SYMBOL(nlmsvc_ops); 49 50 static DEFINE_MUTEX(nlmsvc_mutex); 51 static unsigned int nlmsvc_users; 52 static struct task_struct *nlmsvc_task; 53 static struct svc_serv *nlmsvc_serv; 54 int nlmsvc_grace_period; 55 unsigned long nlmsvc_timeout; 56 57 /* 58 * These can be set at insmod time (useful for NFS as root filesystem), 59 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 60 */ 61 static unsigned long nlm_grace_period; 62 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; 63 static int nlm_udpport, nlm_tcpport; 64 int nsm_use_hostnames = 0; 65 66 /* 67 * Constants needed for the sysctl interface. 68 */ 69 static const unsigned long nlm_grace_period_min = 0; 70 static const unsigned long nlm_grace_period_max = 240; 71 static const unsigned long nlm_timeout_min = 3; 72 static const unsigned long nlm_timeout_max = 20; 73 static const int nlm_port_min = 0, nlm_port_max = 65535; 74 75 #ifdef CONFIG_SYSCTL 76 static struct ctl_table_header * nlm_sysctl_table; 77 #endif 78 79 static unsigned long get_lockd_grace_period(void) 80 { 81 /* Note: nlm_timeout should always be nonzero */ 82 if (nlm_grace_period) 83 return roundup(nlm_grace_period, nlm_timeout) * HZ; 84 else 85 return nlm_timeout * 5 * HZ; 86 } 87 88 unsigned long get_nfs_grace_period(void) 89 { 90 unsigned long lockdgrace = get_lockd_grace_period(); 91 unsigned long nfsdgrace = 0; 92 93 if (nlmsvc_ops) 94 nfsdgrace = nlmsvc_ops->get_grace_period(); 95 96 return max(lockdgrace, nfsdgrace); 97 } 98 EXPORT_SYMBOL(get_nfs_grace_period); 99 100 static unsigned long set_grace_period(void) 101 { 102 nlmsvc_grace_period = 1; 103 return get_nfs_grace_period() + jiffies; 104 } 105 106 static inline void clear_grace_period(void) 107 { 108 nlmsvc_grace_period = 0; 109 } 110 111 /* 112 * This is the lockd kernel thread 113 */ 114 static int 115 lockd(void *vrqstp) 116 { 117 int err = 0, preverr = 0; 118 struct svc_rqst *rqstp = vrqstp; 119 unsigned long grace_period_expire; 120 121 /* try_to_freeze() is called from svc_recv() */ 122 set_freezable(); 123 124 /* Allow SIGKILL to tell lockd to drop all of its locks */ 125 allow_signal(SIGKILL); 126 127 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); 128 129 /* 130 * FIXME: it would be nice if lockd didn't spend its entire life 131 * running under the BKL. At the very least, it would be good to 132 * have someone clarify what it's intended to protect here. I've 133 * seen some handwavy posts about posix locking needing to be 134 * done under the BKL, but it's far from clear. 135 */ 136 lock_kernel(); 137 138 if (!nlm_timeout) 139 nlm_timeout = LOCKD_DFLT_TIMEO; 140 nlmsvc_timeout = nlm_timeout * HZ; 141 142 grace_period_expire = set_grace_period(); 143 144 /* 145 * The main request loop. We don't terminate until the last 146 * NFS mount or NFS daemon has gone away. 147 */ 148 while (!kthread_should_stop()) { 149 long timeout = MAX_SCHEDULE_TIMEOUT; 150 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); 151 152 if (signalled()) { 153 flush_signals(current); 154 if (nlmsvc_ops) { 155 nlmsvc_invalidate_all(); 156 grace_period_expire = set_grace_period(); 157 } 158 continue; 159 } 160 161 /* 162 * Retry any blocked locks that have been notified by 163 * the VFS. Don't do this during grace period. 164 * (Theoretically, there shouldn't even be blocked locks 165 * during grace period). 166 */ 167 if (!nlmsvc_grace_period) { 168 timeout = nlmsvc_retry_blocked(); 169 } else if (time_before(grace_period_expire, jiffies)) 170 clear_grace_period(); 171 172 /* 173 * Find a socket with data available and call its 174 * recvfrom routine. 175 */ 176 err = svc_recv(rqstp, timeout); 177 if (err == -EAGAIN || err == -EINTR) { 178 preverr = err; 179 continue; 180 } 181 if (err < 0) { 182 if (err != preverr) { 183 printk(KERN_WARNING "%s: unexpected error " 184 "from svc_recv (%d)\n", __func__, err); 185 preverr = err; 186 } 187 schedule_timeout_interruptible(HZ); 188 continue; 189 } 190 preverr = err; 191 192 dprintk("lockd: request from %s\n", 193 svc_print_addr(rqstp, buf, sizeof(buf))); 194 195 svc_process(rqstp); 196 } 197 198 flush_signals(current); 199 if (nlmsvc_ops) 200 nlmsvc_invalidate_all(); 201 nlm_shutdown_hosts(); 202 203 unlock_kernel(); 204 205 nlmsvc_task = NULL; 206 nlmsvc_serv = NULL; 207 208 /* Exit the RPC thread */ 209 svc_exit_thread(rqstp); 210 211 return 0; 212 } 213 214 /* 215 * Make any sockets that are needed but not present. 216 * If nlm_udpport or nlm_tcpport were set as module 217 * options, make those sockets unconditionally 218 */ 219 static int make_socks(struct svc_serv *serv, int proto) 220 { 221 static int warned; 222 struct svc_xprt *xprt; 223 int err = 0; 224 225 if (proto == IPPROTO_UDP || nlm_udpport) { 226 xprt = svc_find_xprt(serv, "udp", 0, 0); 227 if (!xprt) 228 err = svc_create_xprt(serv, "udp", nlm_udpport, 229 SVC_SOCK_DEFAULTS); 230 else 231 svc_xprt_put(xprt); 232 } 233 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) { 234 xprt = svc_find_xprt(serv, "tcp", 0, 0); 235 if (!xprt) 236 err = svc_create_xprt(serv, "tcp", nlm_tcpport, 237 SVC_SOCK_DEFAULTS); 238 else 239 svc_xprt_put(xprt); 240 } 241 if (err >= 0) { 242 warned = 0; 243 err = 0; 244 } else if (warned++ == 0) 245 printk(KERN_WARNING 246 "lockd_up: makesock failed, error=%d\n", err); 247 return err; 248 } 249 250 /* 251 * Bring up the lockd process if it's not already up. 252 */ 253 int 254 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 255 { 256 struct svc_serv *serv; 257 struct svc_rqst *rqstp; 258 int error = 0; 259 260 mutex_lock(&nlmsvc_mutex); 261 /* 262 * Check whether we're already up and running. 263 */ 264 if (nlmsvc_serv) { 265 if (proto) 266 error = make_socks(nlmsvc_serv, proto); 267 goto out; 268 } 269 270 /* 271 * Sanity check: if there's no pid, 272 * we should be the first user ... 273 */ 274 if (nlmsvc_users) 275 printk(KERN_WARNING 276 "lockd_up: no pid, %d users??\n", nlmsvc_users); 277 278 error = -ENOMEM; 279 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 280 if (!serv) { 281 printk(KERN_WARNING "lockd_up: create service failed\n"); 282 goto out; 283 } 284 285 if ((error = make_socks(serv, proto)) < 0) 286 goto destroy_and_out; 287 288 /* 289 * Create the kernel thread and wait for it to start. 290 */ 291 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]); 292 if (IS_ERR(rqstp)) { 293 error = PTR_ERR(rqstp); 294 printk(KERN_WARNING 295 "lockd_up: svc_rqst allocation failed, error=%d\n", 296 error); 297 goto destroy_and_out; 298 } 299 300 svc_sock_update_bufs(serv); 301 nlmsvc_serv = rqstp->rq_server; 302 303 nlmsvc_task = kthread_run(lockd, rqstp, serv->sv_name); 304 if (IS_ERR(nlmsvc_task)) { 305 error = PTR_ERR(nlmsvc_task); 306 nlmsvc_task = NULL; 307 nlmsvc_serv = NULL; 308 printk(KERN_WARNING 309 "lockd_up: kthread_run failed, error=%d\n", error); 310 svc_exit_thread(rqstp); 311 goto destroy_and_out; 312 } 313 314 /* 315 * Note: svc_serv structures have an initial use count of 1, 316 * so we exit through here on both success and failure. 317 */ 318 destroy_and_out: 319 svc_destroy(serv); 320 out: 321 if (!error) 322 nlmsvc_users++; 323 mutex_unlock(&nlmsvc_mutex); 324 return error; 325 } 326 EXPORT_SYMBOL(lockd_up); 327 328 /* 329 * Decrement the user count and bring down lockd if we're the last. 330 */ 331 void 332 lockd_down(void) 333 { 334 mutex_lock(&nlmsvc_mutex); 335 if (nlmsvc_users) { 336 if (--nlmsvc_users) 337 goto out; 338 } else { 339 printk(KERN_ERR "lockd_down: no users! task=%p\n", 340 nlmsvc_task); 341 BUG(); 342 } 343 344 if (!nlmsvc_task) { 345 printk(KERN_ERR "lockd_down: no lockd running.\n"); 346 BUG(); 347 } 348 kthread_stop(nlmsvc_task); 349 out: 350 mutex_unlock(&nlmsvc_mutex); 351 } 352 EXPORT_SYMBOL(lockd_down); 353 354 #ifdef CONFIG_SYSCTL 355 356 /* 357 * Sysctl parameters (same as module parameters, different interface). 358 */ 359 360 static ctl_table nlm_sysctls[] = { 361 { 362 .ctl_name = CTL_UNNUMBERED, 363 .procname = "nlm_grace_period", 364 .data = &nlm_grace_period, 365 .maxlen = sizeof(unsigned long), 366 .mode = 0644, 367 .proc_handler = &proc_doulongvec_minmax, 368 .extra1 = (unsigned long *) &nlm_grace_period_min, 369 .extra2 = (unsigned long *) &nlm_grace_period_max, 370 }, 371 { 372 .ctl_name = CTL_UNNUMBERED, 373 .procname = "nlm_timeout", 374 .data = &nlm_timeout, 375 .maxlen = sizeof(unsigned long), 376 .mode = 0644, 377 .proc_handler = &proc_doulongvec_minmax, 378 .extra1 = (unsigned long *) &nlm_timeout_min, 379 .extra2 = (unsigned long *) &nlm_timeout_max, 380 }, 381 { 382 .ctl_name = CTL_UNNUMBERED, 383 .procname = "nlm_udpport", 384 .data = &nlm_udpport, 385 .maxlen = sizeof(int), 386 .mode = 0644, 387 .proc_handler = &proc_dointvec_minmax, 388 .extra1 = (int *) &nlm_port_min, 389 .extra2 = (int *) &nlm_port_max, 390 }, 391 { 392 .ctl_name = CTL_UNNUMBERED, 393 .procname = "nlm_tcpport", 394 .data = &nlm_tcpport, 395 .maxlen = sizeof(int), 396 .mode = 0644, 397 .proc_handler = &proc_dointvec_minmax, 398 .extra1 = (int *) &nlm_port_min, 399 .extra2 = (int *) &nlm_port_max, 400 }, 401 { 402 .ctl_name = CTL_UNNUMBERED, 403 .procname = "nsm_use_hostnames", 404 .data = &nsm_use_hostnames, 405 .maxlen = sizeof(int), 406 .mode = 0644, 407 .proc_handler = &proc_dointvec, 408 }, 409 { 410 .ctl_name = CTL_UNNUMBERED, 411 .procname = "nsm_local_state", 412 .data = &nsm_local_state, 413 .maxlen = sizeof(int), 414 .mode = 0644, 415 .proc_handler = &proc_dointvec, 416 }, 417 { .ctl_name = 0 } 418 }; 419 420 static ctl_table nlm_sysctl_dir[] = { 421 { 422 .ctl_name = CTL_UNNUMBERED, 423 .procname = "nfs", 424 .mode = 0555, 425 .child = nlm_sysctls, 426 }, 427 { .ctl_name = 0 } 428 }; 429 430 static ctl_table nlm_sysctl_root[] = { 431 { 432 .ctl_name = CTL_FS, 433 .procname = "fs", 434 .mode = 0555, 435 .child = nlm_sysctl_dir, 436 }, 437 { .ctl_name = 0 } 438 }; 439 440 #endif /* CONFIG_SYSCTL */ 441 442 /* 443 * Module (and sysfs) parameters. 444 */ 445 446 #define param_set_min_max(name, type, which_strtol, min, max) \ 447 static int param_set_##name(const char *val, struct kernel_param *kp) \ 448 { \ 449 char *endp; \ 450 __typeof__(type) num = which_strtol(val, &endp, 0); \ 451 if (endp == val || *endp || num < (min) || num > (max)) \ 452 return -EINVAL; \ 453 *((int *) kp->arg) = num; \ 454 return 0; \ 455 } 456 457 static inline int is_callback(u32 proc) 458 { 459 return proc == NLMPROC_GRANTED 460 || proc == NLMPROC_GRANTED_MSG 461 || proc == NLMPROC_TEST_RES 462 || proc == NLMPROC_LOCK_RES 463 || proc == NLMPROC_CANCEL_RES 464 || proc == NLMPROC_UNLOCK_RES 465 || proc == NLMPROC_NSM_NOTIFY; 466 } 467 468 469 static int lockd_authenticate(struct svc_rqst *rqstp) 470 { 471 rqstp->rq_client = NULL; 472 switch (rqstp->rq_authop->flavour) { 473 case RPC_AUTH_NULL: 474 case RPC_AUTH_UNIX: 475 if (rqstp->rq_proc == 0) 476 return SVC_OK; 477 if (is_callback(rqstp->rq_proc)) { 478 /* Leave it to individual procedures to 479 * call nlmsvc_lookup_host(rqstp) 480 */ 481 return SVC_OK; 482 } 483 return svc_set_client(rqstp); 484 } 485 return SVC_DENIED; 486 } 487 488 489 param_set_min_max(port, int, simple_strtol, 0, 65535) 490 param_set_min_max(grace_period, unsigned long, simple_strtoul, 491 nlm_grace_period_min, nlm_grace_period_max) 492 param_set_min_max(timeout, unsigned long, simple_strtoul, 493 nlm_timeout_min, nlm_timeout_max) 494 495 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 496 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 497 MODULE_LICENSE("GPL"); 498 499 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 500 &nlm_grace_period, 0644); 501 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 502 &nlm_timeout, 0644); 503 module_param_call(nlm_udpport, param_set_port, param_get_int, 504 &nlm_udpport, 0644); 505 module_param_call(nlm_tcpport, param_set_port, param_get_int, 506 &nlm_tcpport, 0644); 507 module_param(nsm_use_hostnames, bool, 0644); 508 509 /* 510 * Initialising and terminating the module. 511 */ 512 513 static int __init init_nlm(void) 514 { 515 #ifdef CONFIG_SYSCTL 516 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 517 return nlm_sysctl_table ? 0 : -ENOMEM; 518 #else 519 return 0; 520 #endif 521 } 522 523 static void __exit exit_nlm(void) 524 { 525 /* FIXME: delete all NLM clients */ 526 nlm_shutdown_hosts(); 527 #ifdef CONFIG_SYSCTL 528 unregister_sysctl_table(nlm_sysctl_table); 529 #endif 530 } 531 532 module_init(init_nlm); 533 module_exit(exit_nlm); 534 535 /* 536 * Define NLM program and procedures 537 */ 538 static struct svc_version nlmsvc_version1 = { 539 .vs_vers = 1, 540 .vs_nproc = 17, 541 .vs_proc = nlmsvc_procedures, 542 .vs_xdrsize = NLMSVC_XDRSIZE, 543 }; 544 static struct svc_version nlmsvc_version3 = { 545 .vs_vers = 3, 546 .vs_nproc = 24, 547 .vs_proc = nlmsvc_procedures, 548 .vs_xdrsize = NLMSVC_XDRSIZE, 549 }; 550 #ifdef CONFIG_LOCKD_V4 551 static struct svc_version nlmsvc_version4 = { 552 .vs_vers = 4, 553 .vs_nproc = 24, 554 .vs_proc = nlmsvc_procedures4, 555 .vs_xdrsize = NLMSVC_XDRSIZE, 556 }; 557 #endif 558 static struct svc_version * nlmsvc_version[] = { 559 [1] = &nlmsvc_version1, 560 [3] = &nlmsvc_version3, 561 #ifdef CONFIG_LOCKD_V4 562 [4] = &nlmsvc_version4, 563 #endif 564 }; 565 566 static struct svc_stat nlmsvc_stats; 567 568 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 569 static struct svc_program nlmsvc_program = { 570 .pg_prog = NLM_PROGRAM, /* program number */ 571 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 572 .pg_vers = nlmsvc_version, /* version table */ 573 .pg_name = "lockd", /* service name */ 574 .pg_class = "nfsd", /* share authentication with nfsd */ 575 .pg_stats = &nlmsvc_stats, /* stats table */ 576 .pg_authenticate = &lockd_authenticate /* export authentication */ 577 }; 578