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_rqst *nlmsvc_rqst; 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 flush_signals(current); 198 if (nlmsvc_ops) 199 nlmsvc_invalidate_all(); 200 nlm_shutdown_hosts(); 201 unlock_kernel(); 202 return 0; 203 } 204 205 /* 206 * Make any sockets that are needed but not present. 207 * If nlm_udpport or nlm_tcpport were set as module 208 * options, make those sockets unconditionally 209 */ 210 static int make_socks(struct svc_serv *serv, int proto) 211 { 212 static int warned; 213 struct svc_xprt *xprt; 214 int err = 0; 215 216 if (proto == IPPROTO_UDP || nlm_udpport) { 217 xprt = svc_find_xprt(serv, "udp", 0, 0); 218 if (!xprt) 219 err = svc_create_xprt(serv, "udp", nlm_udpport, 220 SVC_SOCK_DEFAULTS); 221 else 222 svc_xprt_put(xprt); 223 } 224 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) { 225 xprt = svc_find_xprt(serv, "tcp", 0, 0); 226 if (!xprt) 227 err = svc_create_xprt(serv, "tcp", nlm_tcpport, 228 SVC_SOCK_DEFAULTS); 229 else 230 svc_xprt_put(xprt); 231 } 232 if (err >= 0) { 233 warned = 0; 234 err = 0; 235 } else if (warned++ == 0) 236 printk(KERN_WARNING 237 "lockd_up: makesock failed, error=%d\n", err); 238 return err; 239 } 240 241 /* 242 * Bring up the lockd process if it's not already up. 243 */ 244 int 245 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ 246 { 247 struct svc_serv *serv; 248 int error = 0; 249 250 mutex_lock(&nlmsvc_mutex); 251 /* 252 * Check whether we're already up and running. 253 */ 254 if (nlmsvc_rqst) { 255 if (proto) 256 error = make_socks(nlmsvc_rqst->rq_server, proto); 257 goto out; 258 } 259 260 /* 261 * Sanity check: if there's no pid, 262 * we should be the first user ... 263 */ 264 if (nlmsvc_users) 265 printk(KERN_WARNING 266 "lockd_up: no pid, %d users??\n", nlmsvc_users); 267 268 error = -ENOMEM; 269 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); 270 if (!serv) { 271 printk(KERN_WARNING "lockd_up: create service failed\n"); 272 goto out; 273 } 274 275 if ((error = make_socks(serv, proto)) < 0) 276 goto destroy_and_out; 277 278 /* 279 * Create the kernel thread and wait for it to start. 280 */ 281 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); 282 if (IS_ERR(nlmsvc_rqst)) { 283 error = PTR_ERR(nlmsvc_rqst); 284 nlmsvc_rqst = NULL; 285 printk(KERN_WARNING 286 "lockd_up: svc_rqst allocation failed, error=%d\n", 287 error); 288 goto destroy_and_out; 289 } 290 291 svc_sock_update_bufs(serv); 292 293 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); 294 if (IS_ERR(nlmsvc_task)) { 295 error = PTR_ERR(nlmsvc_task); 296 svc_exit_thread(nlmsvc_rqst); 297 nlmsvc_task = NULL; 298 nlmsvc_rqst = NULL; 299 printk(KERN_WARNING 300 "lockd_up: kthread_run failed, error=%d\n", error); 301 goto destroy_and_out; 302 } 303 304 /* 305 * Note: svc_serv structures have an initial use count of 1, 306 * so we exit through here on both success and failure. 307 */ 308 destroy_and_out: 309 svc_destroy(serv); 310 out: 311 if (!error) 312 nlmsvc_users++; 313 mutex_unlock(&nlmsvc_mutex); 314 return error; 315 } 316 EXPORT_SYMBOL(lockd_up); 317 318 /* 319 * Decrement the user count and bring down lockd if we're the last. 320 */ 321 void 322 lockd_down(void) 323 { 324 mutex_lock(&nlmsvc_mutex); 325 if (nlmsvc_users) { 326 if (--nlmsvc_users) 327 goto out; 328 } else { 329 printk(KERN_ERR "lockd_down: no users! task=%p\n", 330 nlmsvc_task); 331 BUG(); 332 } 333 334 if (!nlmsvc_task) { 335 printk(KERN_ERR "lockd_down: no lockd running.\n"); 336 BUG(); 337 } 338 kthread_stop(nlmsvc_task); 339 svc_exit_thread(nlmsvc_rqst); 340 nlmsvc_task = NULL; 341 nlmsvc_rqst = NULL; 342 out: 343 mutex_unlock(&nlmsvc_mutex); 344 } 345 EXPORT_SYMBOL(lockd_down); 346 347 #ifdef CONFIG_SYSCTL 348 349 /* 350 * Sysctl parameters (same as module parameters, different interface). 351 */ 352 353 static ctl_table nlm_sysctls[] = { 354 { 355 .ctl_name = CTL_UNNUMBERED, 356 .procname = "nlm_grace_period", 357 .data = &nlm_grace_period, 358 .maxlen = sizeof(unsigned long), 359 .mode = 0644, 360 .proc_handler = &proc_doulongvec_minmax, 361 .extra1 = (unsigned long *) &nlm_grace_period_min, 362 .extra2 = (unsigned long *) &nlm_grace_period_max, 363 }, 364 { 365 .ctl_name = CTL_UNNUMBERED, 366 .procname = "nlm_timeout", 367 .data = &nlm_timeout, 368 .maxlen = sizeof(unsigned long), 369 .mode = 0644, 370 .proc_handler = &proc_doulongvec_minmax, 371 .extra1 = (unsigned long *) &nlm_timeout_min, 372 .extra2 = (unsigned long *) &nlm_timeout_max, 373 }, 374 { 375 .ctl_name = CTL_UNNUMBERED, 376 .procname = "nlm_udpport", 377 .data = &nlm_udpport, 378 .maxlen = sizeof(int), 379 .mode = 0644, 380 .proc_handler = &proc_dointvec_minmax, 381 .extra1 = (int *) &nlm_port_min, 382 .extra2 = (int *) &nlm_port_max, 383 }, 384 { 385 .ctl_name = CTL_UNNUMBERED, 386 .procname = "nlm_tcpport", 387 .data = &nlm_tcpport, 388 .maxlen = sizeof(int), 389 .mode = 0644, 390 .proc_handler = &proc_dointvec_minmax, 391 .extra1 = (int *) &nlm_port_min, 392 .extra2 = (int *) &nlm_port_max, 393 }, 394 { 395 .ctl_name = CTL_UNNUMBERED, 396 .procname = "nsm_use_hostnames", 397 .data = &nsm_use_hostnames, 398 .maxlen = sizeof(int), 399 .mode = 0644, 400 .proc_handler = &proc_dointvec, 401 }, 402 { 403 .ctl_name = CTL_UNNUMBERED, 404 .procname = "nsm_local_state", 405 .data = &nsm_local_state, 406 .maxlen = sizeof(int), 407 .mode = 0644, 408 .proc_handler = &proc_dointvec, 409 }, 410 { .ctl_name = 0 } 411 }; 412 413 static ctl_table nlm_sysctl_dir[] = { 414 { 415 .ctl_name = CTL_UNNUMBERED, 416 .procname = "nfs", 417 .mode = 0555, 418 .child = nlm_sysctls, 419 }, 420 { .ctl_name = 0 } 421 }; 422 423 static ctl_table nlm_sysctl_root[] = { 424 { 425 .ctl_name = CTL_FS, 426 .procname = "fs", 427 .mode = 0555, 428 .child = nlm_sysctl_dir, 429 }, 430 { .ctl_name = 0 } 431 }; 432 433 #endif /* CONFIG_SYSCTL */ 434 435 /* 436 * Module (and sysfs) parameters. 437 */ 438 439 #define param_set_min_max(name, type, which_strtol, min, max) \ 440 static int param_set_##name(const char *val, struct kernel_param *kp) \ 441 { \ 442 char *endp; \ 443 __typeof__(type) num = which_strtol(val, &endp, 0); \ 444 if (endp == val || *endp || num < (min) || num > (max)) \ 445 return -EINVAL; \ 446 *((int *) kp->arg) = num; \ 447 return 0; \ 448 } 449 450 static inline int is_callback(u32 proc) 451 { 452 return proc == NLMPROC_GRANTED 453 || proc == NLMPROC_GRANTED_MSG 454 || proc == NLMPROC_TEST_RES 455 || proc == NLMPROC_LOCK_RES 456 || proc == NLMPROC_CANCEL_RES 457 || proc == NLMPROC_UNLOCK_RES 458 || proc == NLMPROC_NSM_NOTIFY; 459 } 460 461 462 static int lockd_authenticate(struct svc_rqst *rqstp) 463 { 464 rqstp->rq_client = NULL; 465 switch (rqstp->rq_authop->flavour) { 466 case RPC_AUTH_NULL: 467 case RPC_AUTH_UNIX: 468 if (rqstp->rq_proc == 0) 469 return SVC_OK; 470 if (is_callback(rqstp->rq_proc)) { 471 /* Leave it to individual procedures to 472 * call nlmsvc_lookup_host(rqstp) 473 */ 474 return SVC_OK; 475 } 476 return svc_set_client(rqstp); 477 } 478 return SVC_DENIED; 479 } 480 481 482 param_set_min_max(port, int, simple_strtol, 0, 65535) 483 param_set_min_max(grace_period, unsigned long, simple_strtoul, 484 nlm_grace_period_min, nlm_grace_period_max) 485 param_set_min_max(timeout, unsigned long, simple_strtoul, 486 nlm_timeout_min, nlm_timeout_max) 487 488 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); 489 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); 490 MODULE_LICENSE("GPL"); 491 492 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, 493 &nlm_grace_period, 0644); 494 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, 495 &nlm_timeout, 0644); 496 module_param_call(nlm_udpport, param_set_port, param_get_int, 497 &nlm_udpport, 0644); 498 module_param_call(nlm_tcpport, param_set_port, param_get_int, 499 &nlm_tcpport, 0644); 500 module_param(nsm_use_hostnames, bool, 0644); 501 502 /* 503 * Initialising and terminating the module. 504 */ 505 506 static int __init init_nlm(void) 507 { 508 #ifdef CONFIG_SYSCTL 509 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); 510 return nlm_sysctl_table ? 0 : -ENOMEM; 511 #else 512 return 0; 513 #endif 514 } 515 516 static void __exit exit_nlm(void) 517 { 518 /* FIXME: delete all NLM clients */ 519 nlm_shutdown_hosts(); 520 #ifdef CONFIG_SYSCTL 521 unregister_sysctl_table(nlm_sysctl_table); 522 #endif 523 } 524 525 module_init(init_nlm); 526 module_exit(exit_nlm); 527 528 /* 529 * Define NLM program and procedures 530 */ 531 static struct svc_version nlmsvc_version1 = { 532 .vs_vers = 1, 533 .vs_nproc = 17, 534 .vs_proc = nlmsvc_procedures, 535 .vs_xdrsize = NLMSVC_XDRSIZE, 536 }; 537 static struct svc_version nlmsvc_version3 = { 538 .vs_vers = 3, 539 .vs_nproc = 24, 540 .vs_proc = nlmsvc_procedures, 541 .vs_xdrsize = NLMSVC_XDRSIZE, 542 }; 543 #ifdef CONFIG_LOCKD_V4 544 static struct svc_version nlmsvc_version4 = { 545 .vs_vers = 4, 546 .vs_nproc = 24, 547 .vs_proc = nlmsvc_procedures4, 548 .vs_xdrsize = NLMSVC_XDRSIZE, 549 }; 550 #endif 551 static struct svc_version * nlmsvc_version[] = { 552 [1] = &nlmsvc_version1, 553 [3] = &nlmsvc_version3, 554 #ifdef CONFIG_LOCKD_V4 555 [4] = &nlmsvc_version4, 556 #endif 557 }; 558 559 static struct svc_stat nlmsvc_stats; 560 561 #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) 562 static struct svc_program nlmsvc_program = { 563 .pg_prog = NLM_PROGRAM, /* program number */ 564 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ 565 .pg_vers = nlmsvc_version, /* version table */ 566 .pg_name = "lockd", /* service name */ 567 .pg_class = "nfsd", /* share authentication with nfsd */ 568 .pg_stats = &nlmsvc_stats, /* stats table */ 569 .pg_authenticate = &lockd_authenticate /* export authentication */ 570 }; 571