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
  29 #include <linux/sunrpc/types.h>
  30 #include <linux/sunrpc/stats.h>
  31 #include <linux/sunrpc/clnt.h>
  32 #include <linux/sunrpc/svc.h>
  33 #include <linux/sunrpc/svcsock.h>
  34 #include <net/ip.h>
  35 #include <linux/lockd/lockd.h>
  36 #include <linux/lockd/sm_inter.h>
  37 #include <linux/nfs.h>
  38
  39 #define NLMDBG_FACILITY         NLMDBG_SVC
  40 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  41 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  42
  43 static struct svc_program       nlmsvc_program;
  44
  45 struct nlmsvc_binding *         nlmsvc_ops;
  46 EXPORT_SYMBOL(nlmsvc_ops);
  47
  48 static DEFINE_MUTEX(nlmsvc_mutex);
  49 static unsigned int             nlmsvc_users;
  50 static pid_t                    nlmsvc_pid;
  51 static struct svc_serv          *nlmsvc_serv;
  52 int                             nlmsvc_grace_period;
  53 unsigned long                   nlmsvc_timeout;
  54
  55 static DECLARE_COMPLETION(lockd_start_done);
  56 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
  57
  58 /*
  59  * These can be set at insmod time (useful for NFS as root filesystem),
  60  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
  61  */
  62 static unsigned long            nlm_grace_period;
  63 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  64 static int                      nlm_udpport, nlm_tcpport;
  65 int                             nsm_use_hostnames = 0;
  66
  67 /*
  68  * Constants needed for the sysctl interface.
  69  */
  70 static const unsigned long      nlm_grace_period_min = 0;
  71 static const unsigned long      nlm_grace_period_max = 240;
  72 static const unsigned long      nlm_timeout_min = 3;
  73 static const unsigned long      nlm_timeout_max = 20;
  74 static const int                nlm_port_min = 0, nlm_port_max = 65535;
  75
  76 static struct ctl_table_header * nlm_sysctl_table;
  77
  78 static unsigned long set_grace_period(void)
  79 {
  80         unsigned long grace_period;
  81
  82         /* Note: nlm_timeout should always be nonzero */
  83         if (nlm_grace_period)
  84                 grace_period = ((nlm_grace_period + nlm_timeout - 1)
  85                                 / nlm_timeout) * nlm_timeout * HZ;
  86         else
  87                 grace_period = nlm_timeout * 5 * HZ;
  88         nlmsvc_grace_period = 1;
  89         return grace_period + jiffies;
  90 }
  91
  92 static inline void clear_grace_period(void)
  93 {
  94         nlmsvc_grace_period = 0;
  95 }
  96
  97 /*
  98  * This is the lockd kernel thread
  99  */
 100 static void
 101 lockd(struct svc_rqst *rqstp)
 102 {
 103         int             err = 0;
 104         unsigned long grace_period_expire;
 105
 106         /* Lock module and set up kernel thread */
 107         /* lockd_up is waiting for us to startup, so will
 108          * be holding a reference to this module, so it
 109          * is safe to just claim another reference
 110          */
 111         __module_get(THIS_MODULE);
 112         lock_kernel();
 113
 114         /*
 115          * Let our maker know we're running.
 116          */
 117         nlmsvc_pid = current->pid;
 118         nlmsvc_serv = rqstp->rq_server;
 119         complete(&lockd_start_done);
 120
 121         daemonize("lockd");
 122
 123         /* Process request with signals blocked, but allow SIGKILL.  */
 124         allow_signal(SIGKILL);
 125
 126         /* kick rpciod */
 127         rpciod_up();
 128
 129         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 130
 131         if (!nlm_timeout)
 132                 nlm_timeout = LOCKD_DFLT_TIMEO;
 133         nlmsvc_timeout = nlm_timeout * HZ;
 134
 135         grace_period_expire = set_grace_period();
 136
 137         /*
 138          * The main request loop. We don't terminate until the last
 139          * NFS mount or NFS daemon has gone away, and we've been sent a
 140          * signal, or else another process has taken over our job.
 141          */
 142         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
 143                 long timeout = MAX_SCHEDULE_TIMEOUT;
 144                 char buf[RPC_MAX_ADDRBUFLEN];
 145
 146                 if (signalled()) {
 147                         flush_signals(current);
 148                         if (nlmsvc_ops) {
 149                                 nlmsvc_invalidate_all();
 150                                 grace_period_expire = set_grace_period();
 151                         }
 152                 }
 153
 154                 /*
 155                  * Retry any blocked locks that have been notified by
 156                  * the VFS. Don't do this during grace period.
 157                  * (Theoretically, there shouldn't even be blocked locks
 158                  * during grace period).
 159                  */
 160                 if (!nlmsvc_grace_period) {
 161                         timeout = nlmsvc_retry_blocked();
 162                 } else if (time_before(grace_period_expire, jiffies))
 163                         clear_grace_period();
 164
 165                 /*
 166                  * Find a socket with data available and call its
 167                  * recvfrom routine.
 168                  */
 169                 err = svc_recv(rqstp, timeout);
 170                 if (err == -EAGAIN || err == -EINTR)
 171                         continue;
 172                 if (err < 0) {
 173                         printk(KERN_WARNING
 174                                "lockd: terminating on error %d\n",
 175                                -err);
 176                         break;
 177                 }
 178
 179                 dprintk("lockd: request from %s\n",
 180                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 181
 182                 svc_process(rqstp);
 183         }
 184
 185         flush_signals(current);
 186
 187         /*
 188          * Check whether there's a new lockd process before
 189          * shutting down the hosts and clearing the slot.
 190          */
 191         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
 192                 if (nlmsvc_ops)
 193                         nlmsvc_invalidate_all();
 194                 nlm_shutdown_hosts();
 195                 nlmsvc_pid = 0;
 196                 nlmsvc_serv = NULL;
 197         } else
 198                 printk(KERN_DEBUG
 199                         "lockd: new process, skipping host shutdown\n");
 200         wake_up(&lockd_exit);
 201
 202         /* Exit the RPC thread */
 203         svc_exit_thread(rqstp);
 204
 205         /* release rpciod */
 206         rpciod_down();
 207
 208         /* Release module */
 209         unlock_kernel();
 210         module_put_and_exit(0);
 211 }
 212
 213
 214 static int find_socket(struct svc_serv *serv, int proto)
 215 {
 216         struct svc_sock *svsk;
 217         int found = 0;
 218         list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
 219                 if (svsk->sk_sk->sk_protocol == proto) {
 220                         found = 1;
 221                         break;
 222                 }
 223         return found;
 224 }
 225
 226 /*
 227  * Make any sockets that are needed but not present.
 228  * If nlm_udpport or nlm_tcpport were set as module
 229  * options, make those sockets unconditionally
 230  */
 231 static int make_socks(struct svc_serv *serv, int proto)
 232 {
 233         static int warned;
 234         int err = 0;
 235
 236         if (proto == IPPROTO_UDP || nlm_udpport)
 237                 if (!find_socket(serv, IPPROTO_UDP))
 238                         err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport,
 239                                                 SVC_SOCK_DEFAULTS);
 240         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
 241                 if (!find_socket(serv, IPPROTO_TCP))
 242                         err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport,
 243                                                 SVC_SOCK_DEFAULTS);
 244
 245         if (err >= 0) {
 246                 warned = 0;
 247                 err = 0;
 248         } else if (warned++ == 0)
 249                 printk(KERN_WARNING
 250                        "lockd_up: makesock failed, error=%d\n", err);
 251         return err;
 252 }
 253
 254 /*
 255  * Bring up the lockd process if it's not already up.
 256  */
 257 int
 258 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 259 {
 260         struct svc_serv *       serv;
 261         int                     error = 0;
 262
 263         mutex_lock(&nlmsvc_mutex);
 264         /*
 265          * Check whether we're already up and running.
 266          */
 267         if (nlmsvc_pid) {
 268                 if (proto)
 269                         error = make_socks(nlmsvc_serv, proto);
 270                 goto out;
 271         }
 272
 273         /*
 274          * Sanity check: if there's no pid,
 275          * we should be the first user ...
 276          */
 277         if (nlmsvc_users)
 278                 printk(KERN_WARNING
 279                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 280
 281         error = -ENOMEM;
 282         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 283         if (!serv) {
 284                 printk(KERN_WARNING "lockd_up: create service failed\n");
 285                 goto out;
 286         }
 287
 288         if ((error = make_socks(serv, proto)) < 0)
 289                 goto destroy_and_out;
 290
 291         /*
 292          * Create the kernel thread and wait for it to start.
 293          */
 294         error = svc_create_thread(lockd, serv);
 295         if (error) {
 296                 printk(KERN_WARNING
 297                         "lockd_up: create thread failed, error=%d\n", error);
 298                 goto destroy_and_out;
 299         }
 300         wait_for_completion(&lockd_start_done);
 301
 302         /*
 303          * Note: svc_serv structures have an initial use count of 1,
 304          * so we exit through here on both success and failure.
 305          */
 306 destroy_and_out:
 307         svc_destroy(serv);
 308 out:
 309         if (!error)
 310                 nlmsvc_users++;
 311         mutex_unlock(&nlmsvc_mutex);
 312         return error;
 313 }
 314 EXPORT_SYMBOL(lockd_up);
 315
 316 /*
 317  * Decrement the user count and bring down lockd if we're the last.
 318  */
 319 void
 320 lockd_down(void)
 321 {
 322         static int warned;
 323
 324         mutex_lock(&nlmsvc_mutex);
 325         if (nlmsvc_users) {
 326                 if (--nlmsvc_users)
 327                         goto out;
 328         } else
 329                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 330
 331         if (!nlmsvc_pid) {
 332                 if (warned++ == 0)
 333                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 334                 goto out;
 335         }
 336         warned = 0;
 337
 338         kill_proc(nlmsvc_pid, SIGKILL, 1);
 339         /*
 340          * Wait for the lockd process to exit, but since we're holding
 341          * the lockd semaphore, we can't wait around forever ...
 342          */
 343         clear_thread_flag(TIF_SIGPENDING);
 344         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 345         if (nlmsvc_pid) {
 346                 printk(KERN_WARNING
 347                         "lockd_down: lockd failed to exit, clearing pid\n");
 348                 nlmsvc_pid = 0;
 349         }
 350         spin_lock_irq(&current->sighand->siglock);
 351         recalc_sigpending();
 352         spin_unlock_irq(&current->sighand->siglock);
 353 out:
 354         mutex_unlock(&nlmsvc_mutex);
 355 }
 356 EXPORT_SYMBOL(lockd_down);
 357
 358 /*
 359  * Sysctl parameters (same as module parameters, different interface).
 360  */
 361
 362 static ctl_table nlm_sysctls[] = {
 363         {
 364                 .ctl_name       = CTL_UNNUMBERED,
 365                 .procname       = "nlm_grace_period",
 366                 .data           = &nlm_grace_period,
 367                 .maxlen         = sizeof(unsigned long),
 368                 .mode           = 0644,
 369                 .proc_handler   = &proc_doulongvec_minmax,
 370                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 371                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 372         },
 373         {
 374                 .ctl_name       = CTL_UNNUMBERED,
 375                 .procname       = "nlm_timeout",
 376                 .data           = &nlm_timeout,
 377                 .maxlen         = sizeof(unsigned long),
 378                 .mode           = 0644,
 379                 .proc_handler   = &proc_doulongvec_minmax,
 380                 .extra1         = (unsigned long *) &nlm_timeout_min,
 381                 .extra2         = (unsigned long *) &nlm_timeout_max,
 382         },
 383         {
 384                 .ctl_name       = CTL_UNNUMBERED,
 385                 .procname       = "nlm_udpport",
 386                 .data           = &nlm_udpport,
 387                 .maxlen         = sizeof(int),
 388                 .mode           = 0644,
 389                 .proc_handler   = &proc_dointvec_minmax,
 390                 .extra1         = (int *) &nlm_port_min,
 391                 .extra2         = (int *) &nlm_port_max,
 392         },
 393         {
 394                 .ctl_name       = CTL_UNNUMBERED,
 395                 .procname       = "nlm_tcpport",
 396                 .data           = &nlm_tcpport,
 397                 .maxlen         = sizeof(int),
 398                 .mode           = 0644,
 399                 .proc_handler   = &proc_dointvec_minmax,
 400                 .extra1         = (int *) &nlm_port_min,
 401                 .extra2         = (int *) &nlm_port_max,
 402         },
 403         {
 404                 .ctl_name       = CTL_UNNUMBERED,
 405                 .procname       = "nsm_use_hostnames",
 406                 .data           = &nsm_use_hostnames,
 407                 .maxlen         = sizeof(int),
 408                 .mode           = 0644,
 409                 .proc_handler   = &proc_dointvec,
 410         },
 411         {
 412                 .ctl_name       = CTL_UNNUMBERED,
 413                 .procname       = "nsm_local_state",
 414                 .data           = &nsm_local_state,
 415                 .maxlen         = sizeof(int),
 416                 .mode           = 0644,
 417                 .proc_handler   = &proc_dointvec,
 418         },
 419         { .ctl_name = 0 }
 420 };
 421
 422 static ctl_table nlm_sysctl_dir[] = {
 423         {
 424                 .ctl_name       = CTL_UNNUMBERED,
 425                 .procname       = "nfs",
 426                 .mode           = 0555,
 427                 .child          = nlm_sysctls,
 428         },
 429         { .ctl_name = 0 }
 430 };
 431
 432 static ctl_table nlm_sysctl_root[] = {
 433         {
 434                 .ctl_name       = CTL_FS,
 435                 .procname       = "fs",
 436                 .mode           = 0555,
 437                 .child          = nlm_sysctl_dir,
 438         },
 439         { .ctl_name = 0 }
 440 };
 441
 442 /*
 443  * Module (and driverfs) 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         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
 516         return nlm_sysctl_table ? 0 : -ENOMEM;
 517 }
 518
 519 static void __exit exit_nlm(void)
 520 {
 521         /* FIXME: delete all NLM clients */
 522         nlm_shutdown_hosts();
 523         unregister_sysctl_table(nlm_sysctl_table);
 524 }
 525
 526 module_init(init_nlm);
 527 module_exit(exit_nlm);
 528
 529 /*
 530  * Define NLM program and procedures
 531  */
 532 static struct svc_version       nlmsvc_version1 = {
 533                 .vs_vers        = 1,
 534                 .vs_nproc       = 17,
 535                 .vs_proc        = nlmsvc_procedures,
 536                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 537 };
 538 static struct svc_version       nlmsvc_version3 = {
 539                 .vs_vers        = 3,
 540                 .vs_nproc       = 24,
 541                 .vs_proc        = nlmsvc_procedures,
 542                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 543 };
 544 #ifdef CONFIG_LOCKD_V4
 545 static struct svc_version       nlmsvc_version4 = {
 546                 .vs_vers        = 4,
 547                 .vs_nproc       = 24,
 548                 .vs_proc        = nlmsvc_procedures4,
 549                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 550 };
 551 #endif
 552 static struct svc_version *     nlmsvc_version[] = {
 553         [1] = &nlmsvc_version1,
 554         [3] = &nlmsvc_version3,
 555 #ifdef CONFIG_LOCKD_V4
 556         [4] = &nlmsvc_version4,
 557 #endif
 558 };
 559
 560 static struct svc_stat          nlmsvc_stats;
 561
 562 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 563 static struct svc_program       nlmsvc_program = {
 564         .pg_prog                = NLM_PROGRAM,          /* program number */
 565         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 566         .pg_vers                = nlmsvc_version,       /* version table */
 567         .pg_name                = "lockd",              /* service name */
 568         .pg_class               = "nfsd",               /* share authentication with nfsd */
 569         .pg_stats               = &nlmsvc_stats,        /* stats table */
 570         .pg_authenticate = &lockd_authenticate  /* export authentication */
 571 };