git.oblomov.eu Git - linux-2.6/blob - fs/lockd/svc.c

   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/freezer.h>
  29
  30 #include <linux/sunrpc/types.h>
  31 #include <linux/sunrpc/stats.h>
  32 #include <linux/sunrpc/clnt.h>
  33 #include <linux/sunrpc/svc.h>
  34 #include <linux/sunrpc/svcsock.h>
  35 #include <net/ip.h>
  36 #include <linux/lockd/lockd.h>
  37 #include <linux/lockd/sm_inter.h>
  38 #include <linux/nfs.h>
  39
  40 #define NLMDBG_FACILITY         NLMDBG_SVC
  41 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  42 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  43
  44 static struct svc_program       nlmsvc_program;
  45
  46 struct nlmsvc_binding *         nlmsvc_ops;
  47 EXPORT_SYMBOL(nlmsvc_ops);
  48
  49 static DEFINE_MUTEX(nlmsvc_mutex);
  50 static unsigned int             nlmsvc_users;
  51 static pid_t                    nlmsvc_pid;
  52 static struct svc_serv          *nlmsvc_serv;
  53 int                             nlmsvc_grace_period;
  54 unsigned long                   nlmsvc_timeout;
  55
  56 static DECLARE_COMPLETION(lockd_start_done);
  57 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
  58
  59 /*
  60  * These can be set at insmod time (useful for NFS as root filesystem),
  61  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
  62  */
  63 static unsigned long            nlm_grace_period;
  64 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  65 static int                      nlm_udpport, nlm_tcpport;
  66 int                             nsm_use_hostnames = 0;
  67
  68 /*
  69  * Constants needed for the sysctl interface.
  70  */
  71 static const unsigned long      nlm_grace_period_min = 0;
  72 static const unsigned long      nlm_grace_period_max = 240;
  73 static const unsigned long      nlm_timeout_min = 3;
  74 static const unsigned long      nlm_timeout_max = 20;
  75 static const int                nlm_port_min = 0, nlm_port_max = 65535;
  76
  77 static struct ctl_table_header * nlm_sysctl_table;
  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 void
 115 lockd(struct svc_rqst *rqstp)
 116 {
 117         int             err = 0;
 118         unsigned long grace_period_expire;
 119
 120         /* Lock module and set up kernel thread */
 121         /* lockd_up is waiting for us to startup, so will
 122          * be holding a reference to this module, so it
 123          * is safe to just claim another reference
 124          */
 125         __module_get(THIS_MODULE);
 126         lock_kernel();
 127
 128         /*
 129          * Let our maker know we're running.
 130          */
 131         nlmsvc_pid = current->pid;
 132         nlmsvc_serv = rqstp->rq_server;
 133         complete(&lockd_start_done);
 134
 135         daemonize("lockd");
 136         set_freezable();
 137
 138         /* Process request with signals blocked, but allow SIGKILL.  */
 139         allow_signal(SIGKILL);
 140
 141         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 142
 143         if (!nlm_timeout)
 144                 nlm_timeout = LOCKD_DFLT_TIMEO;
 145         nlmsvc_timeout = nlm_timeout * HZ;
 146
 147         grace_period_expire = set_grace_period();
 148
 149         /*
 150          * The main request loop. We don't terminate until the last
 151          * NFS mount or NFS daemon has gone away, and we've been sent a
 152          * signal, or else another process has taken over our job.
 153          */
 154         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
 155                 long timeout = MAX_SCHEDULE_TIMEOUT;
 156                 char buf[RPC_MAX_ADDRBUFLEN];
 157
 158                 if (signalled()) {
 159                         flush_signals(current);
 160                         if (nlmsvc_ops) {
 161                                 nlmsvc_invalidate_all();
 162                                 grace_period_expire = set_grace_period();
 163                         }
 164                 }
 165
 166                 /*
 167                  * Retry any blocked locks that have been notified by
 168                  * the VFS. Don't do this during grace period.
 169                  * (Theoretically, there shouldn't even be blocked locks
 170                  * during grace period).
 171                  */
 172                 if (!nlmsvc_grace_period) {
 173                         timeout = nlmsvc_retry_blocked();
 174                 } else if (time_before(grace_period_expire, jiffies))
 175                         clear_grace_period();
 176
 177                 /*
 178                  * Find a socket with data available and call its
 179                  * recvfrom routine.
 180                  */
 181                 err = svc_recv(rqstp, timeout);
 182                 if (err == -EAGAIN || err == -EINTR)
 183                         continue;
 184                 if (err < 0) {
 185                         printk(KERN_WARNING
 186                                "lockd: terminating on error %d\n",
 187                                -err);
 188                         break;
 189                 }
 190
 191                 dprintk("lockd: request from %s\n",
 192                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 193
 194                 svc_process(rqstp);
 195         }
 196
 197         flush_signals(current);
 198
 199         /*
 200          * Check whether there's a new lockd process before
 201          * shutting down the hosts and clearing the slot.
 202          */
 203         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
 204                 if (nlmsvc_ops)
 205                         nlmsvc_invalidate_all();
 206                 nlm_shutdown_hosts();
 207                 nlmsvc_pid = 0;
 208                 nlmsvc_serv = NULL;
 209         } else
 210                 printk(KERN_DEBUG
 211                         "lockd: new process, skipping host shutdown\n");
 212         wake_up(&lockd_exit);
 213
 214         /* Exit the RPC thread */
 215         svc_exit_thread(rqstp);
 216
 217         /* Release module */
 218         unlock_kernel();
 219         module_put_and_exit(0);
 220 }
 221
 222
 223 static int find_socket(struct svc_serv *serv, int proto)
 224 {
 225         struct svc_sock *svsk;
 226         int found = 0;
 227         list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
 228                 if (svsk->sk_sk->sk_protocol == proto) {
 229                         found = 1;
 230                         break;
 231                 }
 232         return found;
 233 }
 234
 235 /*
 236  * Make any sockets that are needed but not present.
 237  * If nlm_udpport or nlm_tcpport were set as module
 238  * options, make those sockets unconditionally
 239  */
 240 static int make_socks(struct svc_serv *serv, int proto)
 241 {
 242         static int warned;
 243         int err = 0;
 244
 245         if (proto == IPPROTO_UDP || nlm_udpport)
 246                 if (!find_socket(serv, IPPROTO_UDP))
 247                         err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport,
 248                                                 SVC_SOCK_DEFAULTS);
 249         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
 250                 if (!find_socket(serv, IPPROTO_TCP))
 251                         err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport,
 252                                                 SVC_SOCK_DEFAULTS);
 253
 254         if (err >= 0) {
 255                 warned = 0;
 256                 err = 0;
 257         } else if (warned++ == 0)
 258                 printk(KERN_WARNING
 259                        "lockd_up: makesock failed, error=%d\n", err);
 260         return err;
 261 }
 262
 263 /*
 264  * Bring up the lockd process if it's not already up.
 265  */
 266 int
 267 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 268 {
 269         struct svc_serv *       serv;
 270         int                     error = 0;
 271
 272         mutex_lock(&nlmsvc_mutex);
 273         /*
 274          * Check whether we're already up and running.
 275          */
 276         if (nlmsvc_pid) {
 277                 if (proto)
 278                         error = make_socks(nlmsvc_serv, proto);
 279                 goto out;
 280         }
 281
 282         /*
 283          * Sanity check: if there's no pid,
 284          * we should be the first user ...
 285          */
 286         if (nlmsvc_users)
 287                 printk(KERN_WARNING
 288                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 289
 290         error = -ENOMEM;
 291         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 292         if (!serv) {
 293                 printk(KERN_WARNING "lockd_up: create service failed\n");
 294                 goto out;
 295         }
 296
 297         if ((error = make_socks(serv, proto)) < 0)
 298                 goto destroy_and_out;
 299
 300         /*
 301          * Create the kernel thread and wait for it to start.
 302          */
 303         error = svc_create_thread(lockd, serv);
 304         if (error) {
 305                 printk(KERN_WARNING
 306                         "lockd_up: create thread failed, error=%d\n", error);
 307                 goto destroy_and_out;
 308         }
 309         wait_for_completion(&lockd_start_done);
 310
 311         /*
 312          * Note: svc_serv structures have an initial use count of 1,
 313          * so we exit through here on both success and failure.
 314          */
 315 destroy_and_out:
 316         svc_destroy(serv);
 317 out:
 318         if (!error)
 319                 nlmsvc_users++;
 320         mutex_unlock(&nlmsvc_mutex);
 321         return error;
 322 }
 323 EXPORT_SYMBOL(lockd_up);
 324
 325 /*
 326  * Decrement the user count and bring down lockd if we're the last.
 327  */
 328 void
 329 lockd_down(void)
 330 {
 331         static int warned;
 332
 333         mutex_lock(&nlmsvc_mutex);
 334         if (nlmsvc_users) {
 335                 if (--nlmsvc_users)
 336                         goto out;
 337         } else
 338                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 339
 340         if (!nlmsvc_pid) {
 341                 if (warned++ == 0)
 342                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 343                 goto out;
 344         }
 345         warned = 0;
 346
 347         kill_proc(nlmsvc_pid, SIGKILL, 1);
 348         /*
 349          * Wait for the lockd process to exit, but since we're holding
 350          * the lockd semaphore, we can't wait around forever ...
 351          */
 352         clear_thread_flag(TIF_SIGPENDING);
 353         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 354         if (nlmsvc_pid) {
 355                 printk(KERN_WARNING
 356                         "lockd_down: lockd failed to exit, clearing pid\n");
 357                 nlmsvc_pid = 0;
 358         }
 359         spin_lock_irq(&current->sighand->siglock);
 360         recalc_sigpending();
 361         spin_unlock_irq(&current->sighand->siglock);
 362 out:
 363         mutex_unlock(&nlmsvc_mutex);
 364 }
 365 EXPORT_SYMBOL(lockd_down);
 366
 367 /*
 368  * Sysctl parameters (same as module parameters, different interface).
 369  */
 370
 371 static ctl_table nlm_sysctls[] = {
 372         {
 373                 .ctl_name       = CTL_UNNUMBERED,
 374                 .procname       = "nlm_grace_period",
 375                 .data           = &nlm_grace_period,
 376                 .maxlen         = sizeof(unsigned long),
 377                 .mode           = 0644,
 378                 .proc_handler   = &proc_doulongvec_minmax,
 379                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 380                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 381         },
 382         {
 383                 .ctl_name       = CTL_UNNUMBERED,
 384                 .procname       = "nlm_timeout",
 385                 .data           = &nlm_timeout,
 386                 .maxlen         = sizeof(unsigned long),
 387                 .mode           = 0644,
 388                 .proc_handler   = &proc_doulongvec_minmax,
 389                 .extra1         = (unsigned long *) &nlm_timeout_min,
 390                 .extra2         = (unsigned long *) &nlm_timeout_max,
 391         },
 392         {
 393                 .ctl_name       = CTL_UNNUMBERED,
 394                 .procname       = "nlm_udpport",
 395                 .data           = &nlm_udpport,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = &proc_dointvec_minmax,
 399                 .extra1         = (int *) &nlm_port_min,
 400                 .extra2         = (int *) &nlm_port_max,
 401         },
 402         {
 403                 .ctl_name       = CTL_UNNUMBERED,
 404                 .procname       = "nlm_tcpport",
 405                 .data           = &nlm_tcpport,
 406                 .maxlen         = sizeof(int),
 407                 .mode           = 0644,
 408                 .proc_handler   = &proc_dointvec_minmax,
 409                 .extra1         = (int *) &nlm_port_min,
 410                 .extra2         = (int *) &nlm_port_max,
 411         },
 412         {
 413                 .ctl_name       = CTL_UNNUMBERED,
 414                 .procname       = "nsm_use_hostnames",
 415                 .data           = &nsm_use_hostnames,
 416                 .maxlen         = sizeof(int),
 417                 .mode           = 0644,
 418                 .proc_handler   = &proc_dointvec,
 419         },
 420         {
 421                 .ctl_name       = CTL_UNNUMBERED,
 422                 .procname       = "nsm_local_state",
 423                 .data           = &nsm_local_state,
 424                 .maxlen         = sizeof(int),
 425                 .mode           = 0644,
 426                 .proc_handler   = &proc_dointvec,
 427         },
 428         { .ctl_name = 0 }
 429 };
 430
 431 static ctl_table nlm_sysctl_dir[] = {
 432         {
 433                 .ctl_name       = CTL_UNNUMBERED,
 434                 .procname       = "nfs",
 435                 .mode           = 0555,
 436                 .child          = nlm_sysctls,
 437         },
 438         { .ctl_name = 0 }
 439 };
 440
 441 static ctl_table nlm_sysctl_root[] = {
 442         {
 443                 .ctl_name       = CTL_FS,
 444                 .procname       = "fs",
 445                 .mode           = 0555,
 446                 .child          = nlm_sysctl_dir,
 447         },
 448         { .ctl_name = 0 }
 449 };
 450
 451 /*
 452  * Module (and sysfs) parameters.
 453  */
 454
 455 #define param_set_min_max(name, type, which_strtol, min, max)           \
 456 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 457 {                                                                       \
 458         char *endp;                                                     \
 459         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 460         if (endp == val || *endp || num < (min) || num > (max))         \
 461                 return -EINVAL;                                         \
 462         *((int *) kp->arg) = num;                                       \
 463         return 0;                                                       \
 464 }
 465
 466 static inline int is_callback(u32 proc)
 467 {
 468         return proc == NLMPROC_GRANTED
 469                 || proc == NLMPROC_GRANTED_MSG
 470                 || proc == NLMPROC_TEST_RES
 471                 || proc == NLMPROC_LOCK_RES
 472                 || proc == NLMPROC_CANCEL_RES
 473                 || proc == NLMPROC_UNLOCK_RES
 474                 || proc == NLMPROC_NSM_NOTIFY;
 475 }
 476
 477
 478 static int lockd_authenticate(struct svc_rqst *rqstp)
 479 {
 480         rqstp->rq_client = NULL;
 481         switch (rqstp->rq_authop->flavour) {
 482                 case RPC_AUTH_NULL:
 483                 case RPC_AUTH_UNIX:
 484                         if (rqstp->rq_proc == 0)
 485                                 return SVC_OK;
 486                         if (is_callback(rqstp->rq_proc)) {
 487                                 /* Leave it to individual procedures to
 488                                  * call nlmsvc_lookup_host(rqstp)
 489                                  */
 490                                 return SVC_OK;
 491                         }
 492                         return svc_set_client(rqstp);
 493         }
 494         return SVC_DENIED;
 495 }
 496
 497
 498 param_set_min_max(port, int, simple_strtol, 0, 65535)
 499 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 500                   nlm_grace_period_min, nlm_grace_period_max)
 501 param_set_min_max(timeout, unsigned long, simple_strtoul,
 502                   nlm_timeout_min, nlm_timeout_max)
 503
 504 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 505 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 506 MODULE_LICENSE("GPL");
 507
 508 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 509                   &nlm_grace_period, 0644);
 510 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 511                   &nlm_timeout, 0644);
 512 module_param_call(nlm_udpport, param_set_port, param_get_int,
 513                   &nlm_udpport, 0644);
 514 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 515                   &nlm_tcpport, 0644);
 516 module_param(nsm_use_hostnames, bool, 0644);
 517
 518 /*
 519  * Initialising and terminating the module.
 520  */
 521
 522 static int __init init_nlm(void)
 523 {
 524         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 525         return nlm_sysctl_table ? 0 : -ENOMEM;
 526 }
 527
 528 static void __exit exit_nlm(void)
 529 {
 530         /* FIXME: delete all NLM clients */
 531         nlm_shutdown_hosts();
 532         unregister_sysctl_table(nlm_sysctl_table);
 533 }
 534
 535 module_init(init_nlm);
 536 module_exit(exit_nlm);
 537
 538 /*
 539  * Define NLM program and procedures
 540  */
 541 static struct svc_version       nlmsvc_version1 = {
 542                 .vs_vers        = 1,
 543                 .vs_nproc       = 17,
 544                 .vs_proc        = nlmsvc_procedures,
 545                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 546 };
 547 static struct svc_version       nlmsvc_version3 = {
 548                 .vs_vers        = 3,
 549                 .vs_nproc       = 24,
 550                 .vs_proc        = nlmsvc_procedures,
 551                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 552 };
 553 #ifdef CONFIG_LOCKD_V4
 554 static struct svc_version       nlmsvc_version4 = {
 555                 .vs_vers        = 4,
 556                 .vs_nproc       = 24,
 557                 .vs_proc        = nlmsvc_procedures4,
 558                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 559 };
 560 #endif
 561 static struct svc_version *     nlmsvc_version[] = {
 562         [1] = &nlmsvc_version1,
 563         [3] = &nlmsvc_version3,
 564 #ifdef CONFIG_LOCKD_V4
 565         [4] = &nlmsvc_version4,
 566 #endif
 567 };
 568
 569 static struct svc_stat          nlmsvc_stats;
 570
 571 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 572 static struct svc_program       nlmsvc_program = {
 573         .pg_prog                = NLM_PROGRAM,          /* program number */
 574         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 575         .pg_vers                = nlmsvc_version,       /* version table */
 576         .pg_name                = "lockd",              /* service name */
 577         .pg_class               = "nfsd",               /* share authentication with nfsd */
 578         .pg_stats               = &nlmsvc_stats,        /* stats table */
 579         .pg_authenticate = &lockd_authenticate  /* export authentication */
 580 };