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 <linux/lockd/lockd.h>
  35 #include <linux/nfs.h>
  36
  37 #define NLMDBG_FACILITY         NLMDBG_SVC
  38 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  39 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  40
  41 static struct svc_program       nlmsvc_program;
  42
  43 struct nlmsvc_binding *         nlmsvc_ops;
  44 EXPORT_SYMBOL(nlmsvc_ops);
  45
  46 static DEFINE_MUTEX(nlmsvc_mutex);
  47 static unsigned int             nlmsvc_users;
  48 static pid_t                    nlmsvc_pid;
  49 int                             nlmsvc_grace_period;
  50 unsigned long                   nlmsvc_timeout;
  51
  52 static DECLARE_COMPLETION(lockd_start_done);
  53 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
  54
  55 /*
  56  * These can be set at insmod time (useful for NFS as root filesystem),
  57  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
  58  */
  59 static unsigned long            nlm_grace_period;
  60 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  61 static int                      nlm_udpport, nlm_tcpport;
  62
  63 /*
  64  * Constants needed for the sysctl interface.
  65  */
  66 static const unsigned long      nlm_grace_period_min = 0;
  67 static const unsigned long      nlm_grace_period_max = 240;
  68 static const unsigned long      nlm_timeout_min = 3;
  69 static const unsigned long      nlm_timeout_max = 20;
  70 static const int                nlm_port_min = 0, nlm_port_max = 65535;
  71
  72 static struct ctl_table_header * nlm_sysctl_table;
  73
  74 static unsigned long set_grace_period(void)
  75 {
  76         unsigned long grace_period;
  77
  78         /* Note: nlm_timeout should always be nonzero */
  79         if (nlm_grace_period)
  80                 grace_period = ((nlm_grace_period + nlm_timeout - 1)
  81                                 / nlm_timeout) * nlm_timeout * HZ;
  82         else
  83                 grace_period = nlm_timeout * 5 * HZ;
  84         nlmsvc_grace_period = 1;
  85         return grace_period + jiffies;
  86 }
  87
  88 static inline void clear_grace_period(void)
  89 {
  90         nlmsvc_grace_period = 0;
  91 }
  92
  93 /*
  94  * This is the lockd kernel thread
  95  */
  96 static void
  97 lockd(struct svc_rqst *rqstp)
  98 {
  99         struct svc_serv *serv = rqstp->rq_server;
 100         int             err = 0;
 101         unsigned long grace_period_expire;
 102
 103         /* Lock module and set up kernel thread */
 104         /* lockd_up is waiting for us to startup, so will
 105          * be holding a reference to this module, so it
 106          * is safe to just claim another reference
 107          */
 108         __module_get(THIS_MODULE);
 109         lock_kernel();
 110
 111         /*
 112          * Let our maker know we're running.
 113          */
 114         nlmsvc_pid = current->pid;
 115         complete(&lockd_start_done);
 116
 117         daemonize("lockd");
 118
 119         /* Process request with signals blocked, but allow SIGKILL.  */
 120         allow_signal(SIGKILL);
 121
 122         /* kick rpciod */
 123         rpciod_up();
 124
 125         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 126
 127         if (!nlm_timeout)
 128                 nlm_timeout = LOCKD_DFLT_TIMEO;
 129         nlmsvc_timeout = nlm_timeout * HZ;
 130
 131         grace_period_expire = set_grace_period();
 132
 133         /*
 134          * The main request loop. We don't terminate until the last
 135          * NFS mount or NFS daemon has gone away, and we've been sent a
 136          * signal, or else another process has taken over our job.
 137          */
 138         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
 139                 long timeout = MAX_SCHEDULE_TIMEOUT;
 140
 141                 if (signalled()) {
 142                         flush_signals(current);
 143                         if (nlmsvc_ops) {
 144                                 nlmsvc_invalidate_all();
 145                                 grace_period_expire = set_grace_period();
 146                         }
 147                 }
 148
 149                 /*
 150                  * Retry any blocked locks that have been notified by
 151                  * the VFS. Don't do this during grace period.
 152                  * (Theoretically, there shouldn't even be blocked locks
 153                  * during grace period).
 154                  */
 155                 if (!nlmsvc_grace_period) {
 156                         timeout = nlmsvc_retry_blocked();
 157                 } else if (time_before(grace_period_expire, jiffies))
 158                         clear_grace_period();
 159
 160                 /*
 161                  * Find a socket with data available and call its
 162                  * recvfrom routine.
 163                  */
 164                 err = svc_recv(serv, rqstp, timeout);
 165                 if (err == -EAGAIN || err == -EINTR)
 166                         continue;
 167                 if (err < 0) {
 168                         printk(KERN_WARNING
 169                                "lockd: terminating on error %d\n",
 170                                -err);
 171                         break;
 172                 }
 173
 174                 dprintk("lockd: request from %08x\n",
 175                         (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
 176
 177                 svc_process(serv, rqstp);
 178
 179         }
 180
 181         flush_signals(current);
 182
 183         /*
 184          * Check whether there's a new lockd process before
 185          * shutting down the hosts and clearing the slot.
 186          */
 187         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
 188                 if (nlmsvc_ops)
 189                         nlmsvc_invalidate_all();
 190                 nlm_shutdown_hosts();
 191                 nlmsvc_pid = 0;
 192         } else
 193                 printk(KERN_DEBUG
 194                         "lockd: new process, skipping host shutdown\n");
 195         wake_up(&lockd_exit);
 196
 197         /* Exit the RPC thread */
 198         svc_exit_thread(rqstp);
 199
 200         /* release rpciod */
 201         rpciod_down();
 202
 203         /* Release module */
 204         unlock_kernel();
 205         module_put_and_exit(0);
 206 }
 207
 208 /*
 209  * Bring up the lockd process if it's not already up.
 210  */
 211 int
 212 lockd_up(void)
 213 {
 214         static int              warned;
 215         struct svc_serv *       serv;
 216         int                     error = 0;
 217
 218         mutex_lock(&nlmsvc_mutex);
 219         /*
 220          * Unconditionally increment the user count ... this is
 221          * the number of clients who _want_ a lockd process.
 222          */
 223         nlmsvc_users++;
 224         /*
 225          * Check whether we're already up and running.
 226          */
 227         if (nlmsvc_pid)
 228                 goto out;
 229
 230         /*
 231          * Sanity check: if there's no pid,
 232          * we should be the first user ...
 233          */
 234         if (nlmsvc_users > 1)
 235                 printk(KERN_WARNING
 236                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 237
 238         error = -ENOMEM;
 239         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE);
 240         if (!serv) {
 241                 printk(KERN_WARNING "lockd_up: create service failed\n");
 242                 goto out;
 243         }
 244
 245         if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0
 246 #ifdef CONFIG_NFSD_TCP
 247          || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
 248 #endif
 249                 ) {
 250                 if (warned++ == 0)
 251                         printk(KERN_WARNING
 252                                 "lockd_up: makesock failed, error=%d\n", error);
 253                 goto destroy_and_out;
 254         }
 255         warned = 0;
 256
 257         /*
 258          * Create the kernel thread and wait for it to start.
 259          */
 260         error = svc_create_thread(lockd, serv);
 261         if (error) {
 262                 printk(KERN_WARNING
 263                         "lockd_up: create thread failed, error=%d\n", error);
 264                 goto destroy_and_out;
 265         }
 266         wait_for_completion(&lockd_start_done);
 267
 268         /*
 269          * Note: svc_serv structures have an initial use count of 1,
 270          * so we exit through here on both success and failure.
 271          */
 272 destroy_and_out:
 273         svc_destroy(serv);
 274 out:
 275         mutex_unlock(&nlmsvc_mutex);
 276         return error;
 277 }
 278 EXPORT_SYMBOL(lockd_up);
 279
 280 /*
 281  * Decrement the user count and bring down lockd if we're the last.
 282  */
 283 void
 284 lockd_down(void)
 285 {
 286         static int warned;
 287
 288         mutex_lock(&nlmsvc_mutex);
 289         if (nlmsvc_users) {
 290                 if (--nlmsvc_users)
 291                         goto out;
 292         } else
 293                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 294
 295         if (!nlmsvc_pid) {
 296                 if (warned++ == 0)
 297                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 298                 goto out;
 299         }
 300         warned = 0;
 301
 302         kill_proc(nlmsvc_pid, SIGKILL, 1);
 303         /*
 304          * Wait for the lockd process to exit, but since we're holding
 305          * the lockd semaphore, we can't wait around forever ...
 306          */
 307         clear_thread_flag(TIF_SIGPENDING);
 308         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 309         if (nlmsvc_pid) {
 310                 printk(KERN_WARNING
 311                         "lockd_down: lockd failed to exit, clearing pid\n");
 312                 nlmsvc_pid = 0;
 313         }
 314         spin_lock_irq(&current->sighand->siglock);
 315         recalc_sigpending();
 316         spin_unlock_irq(&current->sighand->siglock);
 317 out:
 318         mutex_unlock(&nlmsvc_mutex);
 319 }
 320 EXPORT_SYMBOL(lockd_down);
 321
 322 /*
 323  * Sysctl parameters (same as module parameters, different interface).
 324  */
 325
 326 /* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
 327 #define CTL_UNNUMBERED          -2
 328
 329 static ctl_table nlm_sysctls[] = {
 330         {
 331                 .ctl_name       = CTL_UNNUMBERED,
 332                 .procname       = "nlm_grace_period",
 333                 .data           = &nlm_grace_period,
 334                 .maxlen         = sizeof(unsigned long),
 335                 .mode           = 0644,
 336                 .proc_handler   = &proc_doulongvec_minmax,
 337                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 338                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 339         },
 340         {
 341                 .ctl_name       = CTL_UNNUMBERED,
 342                 .procname       = "nlm_timeout",
 343                 .data           = &nlm_timeout,
 344                 .maxlen         = sizeof(unsigned long),
 345                 .mode           = 0644,
 346                 .proc_handler   = &proc_doulongvec_minmax,
 347                 .extra1         = (unsigned long *) &nlm_timeout_min,
 348                 .extra2         = (unsigned long *) &nlm_timeout_max,
 349         },
 350         {
 351                 .ctl_name       = CTL_UNNUMBERED,
 352                 .procname       = "nlm_udpport",
 353                 .data           = &nlm_udpport,
 354                 .maxlen         = sizeof(int),
 355                 .mode           = 0644,
 356                 .proc_handler   = &proc_dointvec_minmax,
 357                 .extra1         = (int *) &nlm_port_min,
 358                 .extra2         = (int *) &nlm_port_max,
 359         },
 360         {
 361                 .ctl_name       = CTL_UNNUMBERED,
 362                 .procname       = "nlm_tcpport",
 363                 .data           = &nlm_tcpport,
 364                 .maxlen         = sizeof(int),
 365                 .mode           = 0644,
 366                 .proc_handler   = &proc_dointvec_minmax,
 367                 .extra1         = (int *) &nlm_port_min,
 368                 .extra2         = (int *) &nlm_port_max,
 369         },
 370         { .ctl_name = 0 }
 371 };
 372
 373 static ctl_table nlm_sysctl_dir[] = {
 374         {
 375                 .ctl_name       = CTL_UNNUMBERED,
 376                 .procname       = "nfs",
 377                 .mode           = 0555,
 378                 .child          = nlm_sysctls,
 379         },
 380         { .ctl_name = 0 }
 381 };
 382
 383 static ctl_table nlm_sysctl_root[] = {
 384         {
 385                 .ctl_name       = CTL_FS,
 386                 .procname       = "fs",
 387                 .mode           = 0555,
 388                 .child          = nlm_sysctl_dir,
 389         },
 390         { .ctl_name = 0 }
 391 };
 392
 393 /*
 394  * Module (and driverfs) parameters.
 395  */
 396
 397 #define param_set_min_max(name, type, which_strtol, min, max)           \
 398 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 399 {                                                                       \
 400         char *endp;                                                     \
 401         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 402         if (endp == val || *endp || num < (min) || num > (max))         \
 403                 return -EINVAL;                                         \
 404         *((int *) kp->arg) = num;                                       \
 405         return 0;                                                       \
 406 }
 407
 408 static inline int is_callback(u32 proc)
 409 {
 410         return proc == NLMPROC_GRANTED
 411                 || proc == NLMPROC_GRANTED_MSG
 412                 || proc == NLMPROC_TEST_RES
 413                 || proc == NLMPROC_LOCK_RES
 414                 || proc == NLMPROC_CANCEL_RES
 415                 || proc == NLMPROC_UNLOCK_RES
 416                 || proc == NLMPROC_NSM_NOTIFY;
 417 }
 418
 419
 420 static int lockd_authenticate(struct svc_rqst *rqstp)
 421 {
 422         rqstp->rq_client = NULL;
 423         switch (rqstp->rq_authop->flavour) {
 424                 case RPC_AUTH_NULL:
 425                 case RPC_AUTH_UNIX:
 426                         if (rqstp->rq_proc == 0)
 427                                 return SVC_OK;
 428                         if (is_callback(rqstp->rq_proc)) {
 429                                 /* Leave it to individual procedures to
 430                                  * call nlmsvc_lookup_host(rqstp)
 431                                  */
 432                                 return SVC_OK;
 433                         }
 434                         return svc_set_client(rqstp);
 435         }
 436         return SVC_DENIED;
 437 }
 438
 439
 440 param_set_min_max(port, int, simple_strtol, 0, 65535)
 441 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 442                   nlm_grace_period_min, nlm_grace_period_max)
 443 param_set_min_max(timeout, unsigned long, simple_strtoul,
 444                   nlm_timeout_min, nlm_timeout_max)
 445
 446 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 447 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 448 MODULE_LICENSE("GPL");
 449
 450 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 451                   &nlm_grace_period, 0644);
 452 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 453                   &nlm_timeout, 0644);
 454 module_param_call(nlm_udpport, param_set_port, param_get_int,
 455                   &nlm_udpport, 0644);
 456 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 457                   &nlm_tcpport, 0644);
 458
 459 /*
 460  * Initialising and terminating the module.
 461  */
 462
 463 static int __init init_nlm(void)
 464 {
 465         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
 466         return nlm_sysctl_table ? 0 : -ENOMEM;
 467 }
 468
 469 static void __exit exit_nlm(void)
 470 {
 471         /* FIXME: delete all NLM clients */
 472         nlm_shutdown_hosts();
 473         unregister_sysctl_table(nlm_sysctl_table);
 474 }
 475
 476 module_init(init_nlm);
 477 module_exit(exit_nlm);
 478
 479 /*
 480  * Define NLM program and procedures
 481  */
 482 static struct svc_version       nlmsvc_version1 = {
 483                 .vs_vers        = 1,
 484                 .vs_nproc       = 17,
 485                 .vs_proc        = nlmsvc_procedures,
 486                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 487 };
 488 static struct svc_version       nlmsvc_version3 = {
 489                 .vs_vers        = 3,
 490                 .vs_nproc       = 24,
 491                 .vs_proc        = nlmsvc_procedures,
 492                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 493 };
 494 #ifdef CONFIG_LOCKD_V4
 495 static struct svc_version       nlmsvc_version4 = {
 496                 .vs_vers        = 4,
 497                 .vs_nproc       = 24,
 498                 .vs_proc        = nlmsvc_procedures4,
 499                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 500 };
 501 #endif
 502 static struct svc_version *     nlmsvc_version[] = {
 503         [1] = &nlmsvc_version1,
 504         [3] = &nlmsvc_version3,
 505 #ifdef CONFIG_LOCKD_V4
 506         [4] = &nlmsvc_version4,
 507 #endif
 508 };
 509
 510 static struct svc_stat          nlmsvc_stats;
 511
 512 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 513 static struct svc_program       nlmsvc_program = {
 514         .pg_prog                = NLM_PROGRAM,          /* program number */
 515         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 516         .pg_vers                = nlmsvc_version,       /* version table */
 517         .pg_name                = "lockd",              /* service name */
 518         .pg_class               = "nfsd",               /* share authentication with nfsd */
 519         .pg_stats               = &nlmsvc_stats,        /* stats table */
 520         .pg_authenticate = &lockd_authenticate  /* export authentication */
 521 };