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/config.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/sysctl.h>
  19 #include <linux/moduleparam.h>
  20
  21 #include <linux/sched.h>
  22 #include <linux/errno.h>
  23 #include <linux/in.h>
  24 #include <linux/uio.h>
  25 #include <linux/slab.h>
  26 #include <linux/smp.h>
  27 #include <linux/smp_lock.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/lockd/sm_inter.h>
  36 #include <linux/nfs.h>
  37
  38 #define NLMDBG_FACILITY         NLMDBG_SVC
  39 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  40 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  41
  42 static struct svc_program       nlmsvc_program;
  43 extern struct svc_program       nsmsvc_program;
  44
  45 struct nlmsvc_binding *         nlmsvc_ops;
  46 EXPORT_SYMBOL(nlmsvc_ops);
  47
  48 static DECLARE_MUTEX(nlmsvc_sema);
  49 static unsigned int             nlmsvc_users;
  50 static pid_t                    nlmsvc_pid;
  51 int                             nlmsvc_grace_period;
  52 unsigned long                   nlmsvc_timeout;
  53
  54 static DECLARE_MUTEX_LOCKED(lockd_start);
  55 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
  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 static int                      nlm_use_kstatd = 1;
  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 static struct ctl_table_header * nlm_sysctl_table;
  76
  77 static unsigned long set_grace_period(void)
  78 {
  79         unsigned long grace_period;
  80
  81         /* Note: nlm_timeout should always be nonzero */
  82         if (nlm_grace_period)
  83                 grace_period = ((nlm_grace_period + nlm_timeout - 1)
  84                                 / nlm_timeout) * nlm_timeout * HZ;
  85         else
  86                 grace_period = nlm_timeout * 5 * HZ;
  87         nlmsvc_grace_period = 1;
  88         return grace_period + jiffies;
  89 }
  90
  91 static inline void clear_grace_period(void)
  92 {
  93         nlmsvc_grace_period = 0;
  94 }
  95
  96 /*
  97  * This is the lockd kernel thread
  98  */
  99 static void
 100 lockd(struct svc_rqst *rqstp)
 101 {
 102         struct svc_serv *serv = rqstp->rq_server;
 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         up(&lockd_start);
 119
 120         daemonize("lockd");
 121
 122         /* Set up statd */
 123 #ifdef CONFIG_STATD
 124         if (!nlm_use_kstatd || nsm_kernel_statd_init() < 0)
 125                 nsm_statd_upcalls_init();
 126 #else
 127         nsm_statd_upcalls_init();
 128 #endif
 129
 130         /* Process request with signals blocked, but allow SIGKILL.  */
 131         allow_signal(SIGKILL);
 132
 133         /* kick rpciod */
 134         rpciod_up();
 135
 136 #ifndef CONFIG_STATD
 137         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 138 #else
 139         dprintk("NFS lockd/statd started (ver " LOCKD_VERSION ").\n");
 140 #endif
 141
 142         if (!nlm_timeout)
 143                 nlm_timeout = LOCKD_DFLT_TIMEO;
 144         nlmsvc_timeout = nlm_timeout * HZ;
 145
 146         grace_period_expire = set_grace_period();
 147
 148         /*
 149          * The main request loop. We don't terminate until the last
 150          * NFS mount or NFS daemon has gone away, and we've been sent a
 151          * signal, or else another process has taken over our job.
 152          */
 153         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
 154                 long timeout = MAX_SCHEDULE_TIMEOUT;
 155
 156                 if (signalled()) {
 157                         flush_signals(current);
 158                         if (nlmsvc_ops) {
 159                                 nlmsvc_invalidate_all();
 160                                 grace_period_expire = set_grace_period();
 161                         }
 162                 }
 163
 164                 /*
 165                  * Retry any blocked locks that have been notified by
 166                  * the VFS. Don't do this during grace period.
 167                  * (Theoretically, there shouldn't even be blocked locks
 168                  * during grace period).
 169                  */
 170                 if (!nlmsvc_grace_period) {
 171                         timeout = nlmsvc_retry_blocked();
 172                 } else if (time_before(grace_period_expire, jiffies))
 173                         clear_grace_period();
 174
 175                 /*
 176                  * Find a socket with data available and call its
 177                  * recvfrom routine.
 178                  */
 179                 err = svc_recv(serv, rqstp, timeout);
 180                 if (err == -EAGAIN || err == -EINTR)
 181                         continue;
 182                 if (err < 0) {
 183                         printk(KERN_WARNING
 184                                "lockd: terminating on error %d\n",
 185                                -err);
 186                         break;
 187                 }
 188
 189                 dprintk("lockd: request from %08x\n",
 190                         (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
 191
 192                 svc_process(serv, rqstp);
 193
 194         }
 195
 196         /*
 197          * Check whether there's a new lockd process before
 198          * shutting down the hosts and clearing the slot.
 199          */
 200         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
 201                 if (nlmsvc_ops)
 202                         nlmsvc_invalidate_all();
 203                 nlm_shutdown_hosts();
 204                 nlmsvc_pid = 0;
 205         } else
 206                 printk(KERN_DEBUG
 207                         "lockd: new process, skipping host shutdown\n");
 208         wake_up(&lockd_exit);
 209
 210         /* Exit the RPC thread */
 211         svc_exit_thread(rqstp);
 212
 213         /* release rpciod */
 214         rpciod_down();
 215
 216         /* Release module */
 217         unlock_kernel();
 218         module_put_and_exit(0);
 219 }
 220
 221 /*
 222  * Bring up the lockd process if it's not already up.
 223  */
 224 int
 225 lockd_up(void)
 226 {
 227         static int              warned;
 228         struct svc_program *    prog;
 229         struct svc_serv *       serv;
 230         int                     error = 0;
 231
 232         down(&nlmsvc_sema);
 233         /*
 234          * Unconditionally increment the user count ... this is
 235          * the number of clients who _want_ a lockd process.
 236          */
 237         nlmsvc_users++;
 238         /*
 239          * Check whether we're already up and running.
 240          */
 241         if (nlmsvc_pid)
 242                 goto out;
 243
 244         /*
 245          * Sanity check: if there's no pid,
 246          * we should be the first user ...
 247          */
 248         if (nlmsvc_users > 1)
 249                 printk(KERN_WARNING
 250                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 251
 252         /* Register NLM program and possibly NSM (if using kstatd) */
 253         error = -ENOMEM;
 254         prog = &nlmsvc_program;
 255 #ifdef CONFIG_STATD
 256         if (nlm_use_kstatd)
 257                 prog = &nsmsvc_program;
 258 #endif
 259         serv = svc_create(prog, LOCKD_BUFSIZE);
 260         if (!serv) {
 261                 printk(KERN_WARNING "lockd_up: create service failed\n");
 262                 goto out;
 263         }
 264
 265         if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0
 266 #ifdef CONFIG_NFSD_TCP
 267          || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
 268 #endif
 269                 ) {
 270                 if (warned++ == 0)
 271                         printk(KERN_WARNING
 272                                 "lockd_up: makesock failed, error=%d\n", error);
 273                 goto destroy_and_out;
 274         }
 275         warned = 0;
 276
 277         /*
 278          * Create the kernel thread and wait for it to start.
 279          */
 280         error = svc_create_thread(lockd, serv);
 281         if (error) {
 282                 printk(KERN_WARNING
 283                         "lockd_up: create thread failed, error=%d\n", error);
 284                 goto destroy_and_out;
 285         }
 286         down(&lockd_start);
 287
 288         /*
 289          * Note: svc_serv structures have an initial use count of 1,
 290          * so we exit through here on both success and failure.
 291          */
 292 destroy_and_out:
 293         svc_destroy(serv);
 294 out:
 295         up(&nlmsvc_sema);
 296         return error;
 297 }
 298 EXPORT_SYMBOL(lockd_up);
 299
 300 /*
 301  * Decrement the user count and bring down lockd if we're the last.
 302  */
 303 void
 304 lockd_down(void)
 305 {
 306         static int warned;
 307
 308         down(&nlmsvc_sema);
 309         if (nlmsvc_users) {
 310                 if (--nlmsvc_users)
 311                         goto out;
 312         } else
 313                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 314
 315         if (!nlmsvc_pid) {
 316                 if (warned++ == 0)
 317                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 318                 goto out;
 319         }
 320         warned = 0;
 321
 322         kill_proc(nlmsvc_pid, SIGKILL, 1);
 323         /*
 324          * Wait for the lockd process to exit, but since we're holding
 325          * the lockd semaphore, we can't wait around forever ...
 326          */
 327         clear_thread_flag(TIF_SIGPENDING);
 328         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 329         if (nlmsvc_pid) {
 330                 printk(KERN_WARNING
 331                         "lockd_down: lockd failed to exit, clearing pid\n");
 332                 nlmsvc_pid = 0;
 333         }
 334         spin_lock_irq(&current->sighand->siglock);
 335         recalc_sigpending();
 336         spin_unlock_irq(&current->sighand->siglock);
 337 out:
 338         up(&nlmsvc_sema);
 339 }
 340 EXPORT_SYMBOL(lockd_down);
 341
 342 /*
 343  * Sysctl parameters (same as module parameters, different interface).
 344  */
 345
 346 /* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
 347 #define CTL_UNNUMBERED          -2
 348
 349 static ctl_table nlm_sysctls[] = {
 350         {
 351                 .ctl_name       = CTL_UNNUMBERED,
 352                 .procname       = "nlm_grace_period",
 353                 .data           = &nlm_grace_period,
 354                 .maxlen         = sizeof(int),
 355                 .mode           = 0644,
 356                 .proc_handler   = &proc_doulongvec_minmax,
 357                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 358                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 359         },
 360         {
 361                 .ctl_name       = CTL_UNNUMBERED,
 362                 .procname       = "nlm_timeout",
 363                 .data           = &nlm_timeout,
 364                 .maxlen         = sizeof(int),
 365                 .mode           = 0644,
 366                 .proc_handler   = &proc_doulongvec_minmax,
 367                 .extra1         = (unsigned long *) &nlm_timeout_min,
 368                 .extra2         = (unsigned long *) &nlm_timeout_max,
 369         },
 370         {
 371                 .ctl_name       = CTL_UNNUMBERED,
 372                 .procname       = "nlm_udpport",
 373                 .data           = &nlm_udpport,
 374                 .maxlen         = sizeof(int),
 375                 .mode           = 0644,
 376                 .proc_handler   = &proc_dointvec_minmax,
 377                 .extra1         = (int *) &nlm_port_min,
 378                 .extra2         = (int *) &nlm_port_max,
 379         },
 380         {
 381                 .ctl_name       = CTL_UNNUMBERED,
 382                 .procname       = "nlm_tcpport",
 383                 .data           = &nlm_tcpport,
 384                 .maxlen         = sizeof(int),
 385                 .mode           = 0644,
 386                 .proc_handler   = &proc_dointvec_minmax,
 387                 .extra1         = (int *) &nlm_port_min,
 388                 .extra2         = (int *) &nlm_port_max,
 389         },
 390 #ifdef CONFIG_STATD
 391         {
 392                 .ctl_name       = CTL_UNNUMBERED,
 393                 .procname       = "nlm_use_kstatd",
 394                 .data           = &nlm_use_kstatd,
 395                 .maxlen         = sizeof(int),
 396                 .mode           = 0644,
 397                 .proc_handler   = &proc_dointvec,
 398         },
 399 #endif
 400         { .ctl_name = 0 }
 401 };
 402
 403 static ctl_table nlm_sysctl_dir[] = {
 404         {
 405                 .ctl_name       = CTL_UNNUMBERED,
 406                 .procname       = "nfs",
 407                 .mode           = 0555,
 408                 .child          = nlm_sysctls,
 409         },
 410         { .ctl_name = 0 }
 411 };
 412
 413 static ctl_table nlm_sysctl_root[] = {
 414         {
 415                 .ctl_name       = CTL_FS,
 416                 .procname       = "fs",
 417                 .mode           = 0555,
 418                 .child          = nlm_sysctl_dir,
 419         },
 420         { .ctl_name = 0 }
 421 };
 422
 423 /*
 424  * Module (and driverfs) parameters.
 425  */
 426
 427 #define param_set_min_max(name, type, which_strtol, min, max)           \
 428 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 429 {                                                                       \
 430         char *endp;                                                     \
 431         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 432         if (endp == val || *endp || num < (min) || num > (max))         \
 433                 return -EINVAL;                                         \
 434         *((int *) kp->arg) = num;                                       \
 435         return 0;                                                       \
 436 }
 437
 438 param_set_min_max(port, int, simple_strtol, 0, 65535)
 439 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 440                   nlm_grace_period_min, nlm_grace_period_max)
 441 param_set_min_max(timeout, unsigned long, simple_strtoul,
 442                   nlm_timeout_min, nlm_timeout_max)
 443
 444 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 445 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 446 MODULE_LICENSE("GPL");
 447
 448 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 449                   &nlm_grace_period, 0644);
 450 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 451                   &nlm_timeout, 0644);
 452 module_param_call(nlm_udpport, param_set_port, param_get_int,
 453                   &nlm_udpport, 0644);
 454 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 455                   &nlm_tcpport, 0644);
 456
 457 /*
 458  * Initialising and terminating the module.
 459  */
 460
 461 static int __init init_nlm(void)
 462 {
 463         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
 464         return nlm_sysctl_table ? 0 : -ENOMEM;
 465 }
 466
 467 static void __exit exit_nlm(void)
 468 {
 469         /* FIXME: delete all NLM clients */
 470         nlm_shutdown_hosts();
 471         unregister_sysctl_table(nlm_sysctl_table);
 472 }
 473
 474 module_init(init_nlm);
 475 module_exit(exit_nlm);
 476
 477 /*
 478  * Define NLM program and procedures
 479  */
 480 static struct svc_version       nlmsvc_version1 = {
 481                 .vs_vers        = 1,
 482                 .vs_nproc       = 17,
 483                 .vs_proc        = nlmsvc_procedures,
 484                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 485 };
 486 static struct svc_version       nlmsvc_version3 = {
 487                 .vs_vers        = 3,
 488                 .vs_nproc       = 24,
 489                 .vs_proc        = nlmsvc_procedures,
 490                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 491 };
 492 #ifdef CONFIG_LOCKD_V4
 493 static struct svc_version       nlmsvc_version4 = {
 494                 .vs_vers        = 4,
 495                 .vs_nproc       = 24,
 496                 .vs_proc        = nlmsvc_procedures4,
 497                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 498 };
 499 #endif
 500 static struct svc_version *     nlmsvc_version[] = {
 501         [1] = &nlmsvc_version1,
 502         [3] = &nlmsvc_version3,
 503 #ifdef CONFIG_LOCKD_V4
 504         [4] = &nlmsvc_version4,
 505 #endif
 506 };
 507
 508 static struct svc_stat          nlmsvc_stats;
 509
 510 #define NLM_NRVERS      (sizeof(nlmsvc_version)/sizeof(nlmsvc_version[0]))
 511 static struct svc_program       nlmsvc_program = {
 512         .pg_prog                = NLM_PROGRAM,          /* program number */
 513         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 514         .pg_vers                = nlmsvc_version,       /* version table */
 515         .pg_name                = "lockd",              /* service name */
 516         .pg_class               = "nfsd",               /* share authentication with nfsd */
 517         .pg_stats               = &nlmsvc_stats,        /* stats table */
 518 };
 519
 520 #ifdef CONFIG_STATD
 521 /*
 522  * Define NSM program and procedures
 523  */
 524 static struct svc_version       nsmsvc_version1 = {
 525                 .vs_vers        = 1,
 526                 .vs_nproc       = 7,
 527                 .vs_proc        = nsmsvc_procedures,
 528                 .vs_xdrsize     = SMSVC_XDRSIZE,
 529 };
 530 static struct svc_version *     nsmsvc_version[] = {
 531         [1] = &nsmsvc_version1,
 532 };
 533
 534 static struct svc_stat          nsmsvc_stats;
 535
 536 #define SM_NRVERS       (sizeof(nsmsvc_version)/sizeof(nsmsvc_version[0]))
 537 struct svc_program      nsmsvc_program = {
 538         .pg_next        = &nlmsvc_program,
 539         .pg_prog        = SM_PROGRAM,           /* program number */
 540         .pg_nvers       = SM_NRVERS,            /* number of entries in nlmsvc_version */
 541         .pg_vers        = nsmsvc_version,       /* version table */
 542         .pg_name        = "statd",              /* service name */
 543         .pg_class       = "nfsd",               /* share authentication with nfsd */
 544         .pg_stats       = &nsmsvc_stats,        /* stats table */
 545 };
 546 #endif
 547