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 #ifdef CONFIG_SYSCTL
  78 static struct ctl_table_header * nlm_sysctl_table;
  79 #endif
  80
  81 static unsigned long get_lockd_grace_period(void)
  82 {
  83         /* Note: nlm_timeout should always be nonzero */
  84         if (nlm_grace_period)
  85                 return roundup(nlm_grace_period, nlm_timeout) * HZ;
  86         else
  87                 return nlm_timeout * 5 * HZ;
  88 }
  89
  90 unsigned long get_nfs_grace_period(void)
  91 {
  92         unsigned long lockdgrace = get_lockd_grace_period();
  93         unsigned long nfsdgrace = 0;
  94
  95         if (nlmsvc_ops)
  96                 nfsdgrace = nlmsvc_ops->get_grace_period();
  97
  98         return max(lockdgrace, nfsdgrace);
  99 }
 100 EXPORT_SYMBOL(get_nfs_grace_period);
 101
 102 static unsigned long set_grace_period(void)
 103 {
 104         nlmsvc_grace_period = 1;
 105         return get_nfs_grace_period() + jiffies;
 106 }
 107
 108 static inline void clear_grace_period(void)
 109 {
 110         nlmsvc_grace_period = 0;
 111 }
 112
 113 /*
 114  * This is the lockd kernel thread
 115  */
 116 static void
 117 lockd(struct svc_rqst *rqstp)
 118 {
 119         int             err = 0;
 120         unsigned long grace_period_expire;
 121
 122         /* Lock module and set up kernel thread */
 123         /* lockd_up is waiting for us to startup, so will
 124          * be holding a reference to this module, so it
 125          * is safe to just claim another reference
 126          */
 127         __module_get(THIS_MODULE);
 128         lock_kernel();
 129
 130         /*
 131          * Let our maker know we're running.
 132          */
 133         nlmsvc_pid = current->pid;
 134         nlmsvc_serv = rqstp->rq_server;
 135         complete(&lockd_start_done);
 136
 137         daemonize("lockd");
 138         set_freezable();
 139
 140         /* Process request with signals blocked, but allow SIGKILL.  */
 141         allow_signal(SIGKILL);
 142
 143         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 144
 145         if (!nlm_timeout)
 146                 nlm_timeout = LOCKD_DFLT_TIMEO;
 147         nlmsvc_timeout = nlm_timeout * HZ;
 148
 149         grace_period_expire = set_grace_period();
 150
 151         /*
 152          * The main request loop. We don't terminate until the last
 153          * NFS mount or NFS daemon has gone away, and we've been sent a
 154          * signal, or else another process has taken over our job.
 155          */
 156         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
 157                 long timeout = MAX_SCHEDULE_TIMEOUT;
 158                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 159
 160                 if (signalled()) {
 161                         flush_signals(current);
 162                         if (nlmsvc_ops) {
 163                                 nlmsvc_invalidate_all();
 164                                 grace_period_expire = set_grace_period();
 165                         }
 166                 }
 167
 168                 /*
 169                  * Retry any blocked locks that have been notified by
 170                  * the VFS. Don't do this during grace period.
 171                  * (Theoretically, there shouldn't even be blocked locks
 172                  * during grace period).
 173                  */
 174                 if (!nlmsvc_grace_period) {
 175                         timeout = nlmsvc_retry_blocked();
 176                 } else if (time_before(grace_period_expire, jiffies))
 177                         clear_grace_period();
 178
 179                 /*
 180                  * Find a socket with data available and call its
 181                  * recvfrom routine.
 182                  */
 183                 err = svc_recv(rqstp, timeout);
 184                 if (err == -EAGAIN || err == -EINTR)
 185                         continue;
 186                 if (err < 0) {
 187                         printk(KERN_WARNING
 188                                "lockd: terminating on error %d\n",
 189                                -err);
 190                         break;
 191                 }
 192
 193                 dprintk("lockd: request from %s\n",
 194                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 195
 196                 svc_process(rqstp);
 197         }
 198
 199         flush_signals(current);
 200
 201         /*
 202          * Check whether there's a new lockd process before
 203          * shutting down the hosts and clearing the slot.
 204          */
 205         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
 206                 if (nlmsvc_ops)
 207                         nlmsvc_invalidate_all();
 208                 nlm_shutdown_hosts();
 209                 nlmsvc_pid = 0;
 210                 nlmsvc_serv = NULL;
 211         } else
 212                 printk(KERN_DEBUG
 213                         "lockd: new process, skipping host shutdown\n");
 214         wake_up(&lockd_exit);
 215
 216         /* Exit the RPC thread */
 217         svc_exit_thread(rqstp);
 218
 219         /* Release module */
 220         unlock_kernel();
 221         module_put_and_exit(0);
 222 }
 223
 224 /*
 225  * Make any sockets that are needed but not present.
 226  * If nlm_udpport or nlm_tcpport were set as module
 227  * options, make those sockets unconditionally
 228  */
 229 static int make_socks(struct svc_serv *serv, int proto)
 230 {
 231         static int warned;
 232         struct svc_xprt *xprt;
 233         int err = 0;
 234
 235         if (proto == IPPROTO_UDP || nlm_udpport) {
 236                 xprt = svc_find_xprt(serv, "udp", 0, 0);
 237                 if (!xprt)
 238                         err = svc_create_xprt(serv, "udp", nlm_udpport,
 239                                               SVC_SOCK_DEFAULTS);
 240                 else
 241                         svc_xprt_put(xprt);
 242         }
 243         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
 244                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
 245                 if (!xprt)
 246                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
 247                                               SVC_SOCK_DEFAULTS);
 248                 else
 249                         svc_xprt_put(xprt);
 250         }
 251         if (err >= 0) {
 252                 warned = 0;
 253                 err = 0;
 254         } else if (warned++ == 0)
 255                 printk(KERN_WARNING
 256                        "lockd_up: makesock failed, error=%d\n", err);
 257         return err;
 258 }
 259
 260 /*
 261  * Bring up the lockd process if it's not already up.
 262  */
 263 int
 264 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 265 {
 266         struct svc_serv *       serv;
 267         int                     error = 0;
 268
 269         mutex_lock(&nlmsvc_mutex);
 270         /*
 271          * Check whether we're already up and running.
 272          */
 273         if (nlmsvc_pid) {
 274                 if (proto)
 275                         error = make_socks(nlmsvc_serv, proto);
 276                 goto out;
 277         }
 278
 279         /*
 280          * Sanity check: if there's no pid,
 281          * we should be the first user ...
 282          */
 283         if (nlmsvc_users)
 284                 printk(KERN_WARNING
 285                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 286
 287         error = -ENOMEM;
 288         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 289         if (!serv) {
 290                 printk(KERN_WARNING "lockd_up: create service failed\n");
 291                 goto out;
 292         }
 293
 294         if ((error = make_socks(serv, proto)) < 0)
 295                 goto destroy_and_out;
 296
 297         /*
 298          * Create the kernel thread and wait for it to start.
 299          */
 300         error = svc_create_thread(lockd, serv);
 301         if (error) {
 302                 printk(KERN_WARNING
 303                         "lockd_up: create thread failed, error=%d\n", error);
 304                 goto destroy_and_out;
 305         }
 306         wait_for_completion(&lockd_start_done);
 307
 308         /*
 309          * Note: svc_serv structures have an initial use count of 1,
 310          * so we exit through here on both success and failure.
 311          */
 312 destroy_and_out:
 313         svc_destroy(serv);
 314 out:
 315         if (!error)
 316                 nlmsvc_users++;
 317         mutex_unlock(&nlmsvc_mutex);
 318         return error;
 319 }
 320 EXPORT_SYMBOL(lockd_up);
 321
 322 /*
 323  * Decrement the user count and bring down lockd if we're the last.
 324  */
 325 void
 326 lockd_down(void)
 327 {
 328         static int warned;
 329
 330         mutex_lock(&nlmsvc_mutex);
 331         if (nlmsvc_users) {
 332                 if (--nlmsvc_users)
 333                         goto out;
 334         } else
 335                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 336
 337         if (!nlmsvc_pid) {
 338                 if (warned++ == 0)
 339                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 340                 goto out;
 341         }
 342         warned = 0;
 343
 344         kill_proc(nlmsvc_pid, SIGKILL, 1);
 345         /*
 346          * Wait for the lockd process to exit, but since we're holding
 347          * the lockd semaphore, we can't wait around forever ...
 348          */
 349         clear_thread_flag(TIF_SIGPENDING);
 350         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 351         if (nlmsvc_pid) {
 352                 printk(KERN_WARNING
 353                         "lockd_down: lockd failed to exit, clearing pid\n");
 354                 nlmsvc_pid = 0;
 355         }
 356         spin_lock_irq(&current->sighand->siglock);
 357         recalc_sigpending();
 358         spin_unlock_irq(&current->sighand->siglock);
 359 out:
 360         mutex_unlock(&nlmsvc_mutex);
 361 }
 362 EXPORT_SYMBOL(lockd_down);
 363
 364 #ifdef CONFIG_SYSCTL
 365
 366 /*
 367  * Sysctl parameters (same as module parameters, different interface).
 368  */
 369
 370 static ctl_table nlm_sysctls[] = {
 371         {
 372                 .ctl_name       = CTL_UNNUMBERED,
 373                 .procname       = "nlm_grace_period",
 374                 .data           = &nlm_grace_period,
 375                 .maxlen         = sizeof(unsigned long),
 376                 .mode           = 0644,
 377                 .proc_handler   = &proc_doulongvec_minmax,
 378                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 379                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 380         },
 381         {
 382                 .ctl_name       = CTL_UNNUMBERED,
 383                 .procname       = "nlm_timeout",
 384                 .data           = &nlm_timeout,
 385                 .maxlen         = sizeof(unsigned long),
 386                 .mode           = 0644,
 387                 .proc_handler   = &proc_doulongvec_minmax,
 388                 .extra1         = (unsigned long *) &nlm_timeout_min,
 389                 .extra2         = (unsigned long *) &nlm_timeout_max,
 390         },
 391         {
 392                 .ctl_name       = CTL_UNNUMBERED,
 393                 .procname       = "nlm_udpport",
 394                 .data           = &nlm_udpport,
 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       = "nlm_tcpport",
 404                 .data           = &nlm_tcpport,
 405                 .maxlen         = sizeof(int),
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dointvec_minmax,
 408                 .extra1         = (int *) &nlm_port_min,
 409                 .extra2         = (int *) &nlm_port_max,
 410         },
 411         {
 412                 .ctl_name       = CTL_UNNUMBERED,
 413                 .procname       = "nsm_use_hostnames",
 414                 .data           = &nsm_use_hostnames,
 415                 .maxlen         = sizeof(int),
 416                 .mode           = 0644,
 417                 .proc_handler   = &proc_dointvec,
 418         },
 419         {
 420                 .ctl_name       = CTL_UNNUMBERED,
 421                 .procname       = "nsm_local_state",
 422                 .data           = &nsm_local_state,
 423                 .maxlen         = sizeof(int),
 424                 .mode           = 0644,
 425                 .proc_handler   = &proc_dointvec,
 426         },
 427         { .ctl_name = 0 }
 428 };
 429
 430 static ctl_table nlm_sysctl_dir[] = {
 431         {
 432                 .ctl_name       = CTL_UNNUMBERED,
 433                 .procname       = "nfs",
 434                 .mode           = 0555,
 435                 .child          = nlm_sysctls,
 436         },
 437         { .ctl_name = 0 }
 438 };
 439
 440 static ctl_table nlm_sysctl_root[] = {
 441         {
 442                 .ctl_name       = CTL_FS,
 443                 .procname       = "fs",
 444                 .mode           = 0555,
 445                 .child          = nlm_sysctl_dir,
 446         },
 447         { .ctl_name = 0 }
 448 };
 449
 450 #endif  /* CONFIG_SYSCTL */
 451
 452 /*
 453  * Module (and sysfs) parameters.
 454  */
 455
 456 #define param_set_min_max(name, type, which_strtol, min, max)           \
 457 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 458 {                                                                       \
 459         char *endp;                                                     \
 460         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 461         if (endp == val || *endp || num < (min) || num > (max))         \
 462                 return -EINVAL;                                         \
 463         *((int *) kp->arg) = num;                                       \
 464         return 0;                                                       \
 465 }
 466
 467 static inline int is_callback(u32 proc)
 468 {
 469         return proc == NLMPROC_GRANTED
 470                 || proc == NLMPROC_GRANTED_MSG
 471                 || proc == NLMPROC_TEST_RES
 472                 || proc == NLMPROC_LOCK_RES
 473                 || proc == NLMPROC_CANCEL_RES
 474                 || proc == NLMPROC_UNLOCK_RES
 475                 || proc == NLMPROC_NSM_NOTIFY;
 476 }
 477
 478
 479 static int lockd_authenticate(struct svc_rqst *rqstp)
 480 {
 481         rqstp->rq_client = NULL;
 482         switch (rqstp->rq_authop->flavour) {
 483                 case RPC_AUTH_NULL:
 484                 case RPC_AUTH_UNIX:
 485                         if (rqstp->rq_proc == 0)
 486                                 return SVC_OK;
 487                         if (is_callback(rqstp->rq_proc)) {
 488                                 /* Leave it to individual procedures to
 489                                  * call nlmsvc_lookup_host(rqstp)
 490                                  */
 491                                 return SVC_OK;
 492                         }
 493                         return svc_set_client(rqstp);
 494         }
 495         return SVC_DENIED;
 496 }
 497
 498
 499 param_set_min_max(port, int, simple_strtol, 0, 65535)
 500 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 501                   nlm_grace_period_min, nlm_grace_period_max)
 502 param_set_min_max(timeout, unsigned long, simple_strtoul,
 503                   nlm_timeout_min, nlm_timeout_max)
 504
 505 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 506 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 507 MODULE_LICENSE("GPL");
 508
 509 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 510                   &nlm_grace_period, 0644);
 511 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 512                   &nlm_timeout, 0644);
 513 module_param_call(nlm_udpport, param_set_port, param_get_int,
 514                   &nlm_udpport, 0644);
 515 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 516                   &nlm_tcpport, 0644);
 517 module_param(nsm_use_hostnames, bool, 0644);
 518
 519 /*
 520  * Initialising and terminating the module.
 521  */
 522
 523 static int __init init_nlm(void)
 524 {
 525 #ifdef CONFIG_SYSCTL
 526         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 527         return nlm_sysctl_table ? 0 : -ENOMEM;
 528 #else
 529         return 0;
 530 #endif
 531 }
 532
 533 static void __exit exit_nlm(void)
 534 {
 535         /* FIXME: delete all NLM clients */
 536         nlm_shutdown_hosts();
 537 #ifdef CONFIG_SYSCTL
 538         unregister_sysctl_table(nlm_sysctl_table);
 539 #endif
 540 }
 541
 542 module_init(init_nlm);
 543 module_exit(exit_nlm);
 544
 545 /*
 546  * Define NLM program and procedures
 547  */
 548 static struct svc_version       nlmsvc_version1 = {
 549                 .vs_vers        = 1,
 550                 .vs_nproc       = 17,
 551                 .vs_proc        = nlmsvc_procedures,
 552                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 553 };
 554 static struct svc_version       nlmsvc_version3 = {
 555                 .vs_vers        = 3,
 556                 .vs_nproc       = 24,
 557                 .vs_proc        = nlmsvc_procedures,
 558                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 559 };
 560 #ifdef CONFIG_LOCKD_V4
 561 static struct svc_version       nlmsvc_version4 = {
 562                 .vs_vers        = 4,
 563                 .vs_nproc       = 24,
 564                 .vs_proc        = nlmsvc_procedures4,
 565                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 566 };
 567 #endif
 568 static struct svc_version *     nlmsvc_version[] = {
 569         [1] = &nlmsvc_version1,
 570         [3] = &nlmsvc_version3,
 571 #ifdef CONFIG_LOCKD_V4
 572         [4] = &nlmsvc_version4,
 573 #endif
 574 };
 575
 576 static struct svc_stat          nlmsvc_stats;
 577
 578 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 579 static struct svc_program       nlmsvc_program = {
 580         .pg_prog                = NLM_PROGRAM,          /* program number */
 581         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 582         .pg_vers                = nlmsvc_version,       /* version table */
 583         .pg_name                = "lockd",              /* service name */
 584         .pg_class               = "nfsd",               /* share authentication with nfsd */
 585         .pg_stats               = &nlmsvc_stats,        /* stats table */
 586         .pg_authenticate = &lockd_authenticate  /* export authentication */
 587 };