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
 145                 if (signalled()) {
 146                         flush_signals(current);
 147                         if (nlmsvc_ops) {
 148                                 nlmsvc_invalidate_all();
 149                                 grace_period_expire = set_grace_period();
 150                         }
 151                 }
 152
 153                 /*
 154                  * Retry any blocked locks that have been notified by
 155                  * the VFS. Don't do this during grace period.
 156                  * (Theoretically, there shouldn't even be blocked locks
 157                  * during grace period).
 158                  */
 159                 if (!nlmsvc_grace_period) {
 160                         timeout = nlmsvc_retry_blocked();
 161                 } else if (time_before(grace_period_expire, jiffies))
 162                         clear_grace_period();
 163
 164                 /*
 165                  * Find a socket with data available and call its
 166                  * recvfrom routine.
 167                  */
 168                 err = svc_recv(rqstp, timeout);
 169                 if (err == -EAGAIN || err == -EINTR)
 170                         continue;
 171                 if (err < 0) {
 172                         printk(KERN_WARNING
 173                                "lockd: terminating on error %d\n",
 174                                -err);
 175                         break;
 176                 }
 177
 178                 dprintk("lockd: request from %08x\n",
 179                         (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
 180
 181                 svc_process(rqstp);
 182
 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 static int make_socks(struct svc_serv *serv, int proto)
 227 {
 228         /* Make any sockets that are needed but not present.
 229          * If nlm_udpport or nlm_tcpport were set as module
 230          * options, make those sockets unconditionally
 231          */
 232         static int              warned;
 233         int err = 0;
 234         if (proto == IPPROTO_UDP || nlm_udpport)
 235                 if (!find_socket(serv, IPPROTO_UDP))
 236                         err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport);
 237         if (err == 0 && (proto == IPPROTO_TCP || nlm_tcpport))
 238                 if (!find_socket(serv, IPPROTO_TCP))
 239                         err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport);
 240         if (!err)
 241                 warned = 0;
 242         else if (warned++ == 0)
 243                 printk(KERN_WARNING
 244                        "lockd_up: makesock failed, error=%d\n", err);
 245         return err;
 246 }
 247
 248 /*
 249  * Bring up the lockd process if it's not already up.
 250  */
 251 int
 252 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 253 {
 254         struct svc_serv *       serv;
 255         int                     error = 0;
 256
 257         mutex_lock(&nlmsvc_mutex);
 258         /*
 259          * Check whether we're already up and running.
 260          */
 261         if (nlmsvc_pid) {
 262                 if (proto)
 263                         error = make_socks(nlmsvc_serv, proto);
 264                 goto out;
 265         }
 266
 267         /*
 268          * Sanity check: if there's no pid,
 269          * we should be the first user ...
 270          */
 271         if (nlmsvc_users)
 272                 printk(KERN_WARNING
 273                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 274
 275         error = -ENOMEM;
 276         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 277         if (!serv) {
 278                 printk(KERN_WARNING "lockd_up: create service failed\n");
 279                 goto out;
 280         }
 281
 282         if ((error = make_socks(serv, proto)) < 0)
 283                 goto destroy_and_out;
 284
 285         /*
 286          * Create the kernel thread and wait for it to start.
 287          */
 288         error = svc_create_thread(lockd, serv);
 289         if (error) {
 290                 printk(KERN_WARNING
 291                         "lockd_up: create thread failed, error=%d\n", error);
 292                 goto destroy_and_out;
 293         }
 294         wait_for_completion(&lockd_start_done);
 295
 296         /*
 297          * Note: svc_serv structures have an initial use count of 1,
 298          * so we exit through here on both success and failure.
 299          */
 300 destroy_and_out:
 301         svc_destroy(serv);
 302 out:
 303         if (!error)
 304                 nlmsvc_users++;
 305         mutex_unlock(&nlmsvc_mutex);
 306         return error;
 307 }
 308 EXPORT_SYMBOL(lockd_up);
 309
 310 /*
 311  * Decrement the user count and bring down lockd if we're the last.
 312  */
 313 void
 314 lockd_down(void)
 315 {
 316         static int warned;
 317
 318         mutex_lock(&nlmsvc_mutex);
 319         if (nlmsvc_users) {
 320                 if (--nlmsvc_users)
 321                         goto out;
 322         } else
 323                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
 324
 325         if (!nlmsvc_pid) {
 326                 if (warned++ == 0)
 327                         printk(KERN_WARNING "lockd_down: no lockd running.\n");
 328                 goto out;
 329         }
 330         warned = 0;
 331
 332         kill_proc(nlmsvc_pid, SIGKILL, 1);
 333         /*
 334          * Wait for the lockd process to exit, but since we're holding
 335          * the lockd semaphore, we can't wait around forever ...
 336          */
 337         clear_thread_flag(TIF_SIGPENDING);
 338         interruptible_sleep_on_timeout(&lockd_exit, HZ);
 339         if (nlmsvc_pid) {
 340                 printk(KERN_WARNING
 341                         "lockd_down: lockd failed to exit, clearing pid\n");
 342                 nlmsvc_pid = 0;
 343         }
 344         spin_lock_irq(&current->sighand->siglock);
 345         recalc_sigpending();
 346         spin_unlock_irq(&current->sighand->siglock);
 347 out:
 348         mutex_unlock(&nlmsvc_mutex);
 349 }
 350 EXPORT_SYMBOL(lockd_down);
 351
 352 /*
 353  * Sysctl parameters (same as module parameters, different interface).
 354  */
 355
 356 static ctl_table nlm_sysctls[] = {
 357         {
 358                 .ctl_name       = CTL_UNNUMBERED,
 359                 .procname       = "nlm_grace_period",
 360                 .data           = &nlm_grace_period,
 361                 .maxlen         = sizeof(unsigned long),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_doulongvec_minmax,
 364                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 365                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 366         },
 367         {
 368                 .ctl_name       = CTL_UNNUMBERED,
 369                 .procname       = "nlm_timeout",
 370                 .data           = &nlm_timeout,
 371                 .maxlen         = sizeof(unsigned long),
 372                 .mode           = 0644,
 373                 .proc_handler   = &proc_doulongvec_minmax,
 374                 .extra1         = (unsigned long *) &nlm_timeout_min,
 375                 .extra2         = (unsigned long *) &nlm_timeout_max,
 376         },
 377         {
 378                 .ctl_name       = CTL_UNNUMBERED,
 379                 .procname       = "nlm_udpport",
 380                 .data           = &nlm_udpport,
 381                 .maxlen         = sizeof(int),
 382                 .mode           = 0644,
 383                 .proc_handler   = &proc_dointvec_minmax,
 384                 .extra1         = (int *) &nlm_port_min,
 385                 .extra2         = (int *) &nlm_port_max,
 386         },
 387         {
 388                 .ctl_name       = CTL_UNNUMBERED,
 389                 .procname       = "nlm_tcpport",
 390                 .data           = &nlm_tcpport,
 391                 .maxlen         = sizeof(int),
 392                 .mode           = 0644,
 393                 .proc_handler   = &proc_dointvec_minmax,
 394                 .extra1         = (int *) &nlm_port_min,
 395                 .extra2         = (int *) &nlm_port_max,
 396         },
 397         {
 398                 .ctl_name       = CTL_UNNUMBERED,
 399                 .procname       = "nsm_use_hostnames",
 400                 .data           = &nsm_use_hostnames,
 401                 .maxlen         = sizeof(int),
 402                 .mode           = 0644,
 403                 .proc_handler   = &proc_dointvec,
 404         },
 405         {
 406                 .ctl_name       = CTL_UNNUMBERED,
 407                 .procname       = "nsm_local_state",
 408                 .data           = &nsm_local_state,
 409                 .maxlen         = sizeof(int),
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dointvec,
 412         },
 413         { .ctl_name = 0 }
 414 };
 415
 416 static ctl_table nlm_sysctl_dir[] = {
 417         {
 418                 .ctl_name       = CTL_UNNUMBERED,
 419                 .procname       = "nfs",
 420                 .mode           = 0555,
 421                 .child          = nlm_sysctls,
 422         },
 423         { .ctl_name = 0 }
 424 };
 425
 426 static ctl_table nlm_sysctl_root[] = {
 427         {
 428                 .ctl_name       = CTL_FS,
 429                 .procname       = "fs",
 430                 .mode           = 0555,
 431                 .child          = nlm_sysctl_dir,
 432         },
 433         { .ctl_name = 0 }
 434 };
 435
 436 /*
 437  * Module (and driverfs) parameters.
 438  */
 439
 440 #define param_set_min_max(name, type, which_strtol, min, max)           \
 441 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 442 {                                                                       \
 443         char *endp;                                                     \
 444         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 445         if (endp == val || *endp || num < (min) || num > (max))         \
 446                 return -EINVAL;                                         \
 447         *((int *) kp->arg) = num;                                       \
 448         return 0;                                                       \
 449 }
 450
 451 static inline int is_callback(u32 proc)
 452 {
 453         return proc == NLMPROC_GRANTED
 454                 || proc == NLMPROC_GRANTED_MSG
 455                 || proc == NLMPROC_TEST_RES
 456                 || proc == NLMPROC_LOCK_RES
 457                 || proc == NLMPROC_CANCEL_RES
 458                 || proc == NLMPROC_UNLOCK_RES
 459                 || proc == NLMPROC_NSM_NOTIFY;
 460 }
 461
 462
 463 static int lockd_authenticate(struct svc_rqst *rqstp)
 464 {
 465         rqstp->rq_client = NULL;
 466         switch (rqstp->rq_authop->flavour) {
 467                 case RPC_AUTH_NULL:
 468                 case RPC_AUTH_UNIX:
 469                         if (rqstp->rq_proc == 0)
 470                                 return SVC_OK;
 471                         if (is_callback(rqstp->rq_proc)) {
 472                                 /* Leave it to individual procedures to
 473                                  * call nlmsvc_lookup_host(rqstp)
 474                                  */
 475                                 return SVC_OK;
 476                         }
 477                         return svc_set_client(rqstp);
 478         }
 479         return SVC_DENIED;
 480 }
 481
 482
 483 param_set_min_max(port, int, simple_strtol, 0, 65535)
 484 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 485                   nlm_grace_period_min, nlm_grace_period_max)
 486 param_set_min_max(timeout, unsigned long, simple_strtoul,
 487                   nlm_timeout_min, nlm_timeout_max)
 488
 489 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 490 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 491 MODULE_LICENSE("GPL");
 492
 493 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 494                   &nlm_grace_period, 0644);
 495 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 496                   &nlm_timeout, 0644);
 497 module_param_call(nlm_udpport, param_set_port, param_get_int,
 498                   &nlm_udpport, 0644);
 499 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 500                   &nlm_tcpport, 0644);
 501 module_param(nsm_use_hostnames, bool, 0644);
 502
 503 /*
 504  * Initialising and terminating the module.
 505  */
 506
 507 static int __init init_nlm(void)
 508 {
 509         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
 510         return nlm_sysctl_table ? 0 : -ENOMEM;
 511 }
 512
 513 static void __exit exit_nlm(void)
 514 {
 515         /* FIXME: delete all NLM clients */
 516         nlm_shutdown_hosts();
 517         unregister_sysctl_table(nlm_sysctl_table);
 518 }
 519
 520 module_init(init_nlm);
 521 module_exit(exit_nlm);
 522
 523 /*
 524  * Define NLM program and procedures
 525  */
 526 static struct svc_version       nlmsvc_version1 = {
 527                 .vs_vers        = 1,
 528                 .vs_nproc       = 17,
 529                 .vs_proc        = nlmsvc_procedures,
 530                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 531 };
 532 static struct svc_version       nlmsvc_version3 = {
 533                 .vs_vers        = 3,
 534                 .vs_nproc       = 24,
 535                 .vs_proc        = nlmsvc_procedures,
 536                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 537 };
 538 #ifdef CONFIG_LOCKD_V4
 539 static struct svc_version       nlmsvc_version4 = {
 540                 .vs_vers        = 4,
 541                 .vs_nproc       = 24,
 542                 .vs_proc        = nlmsvc_procedures4,
 543                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 544 };
 545 #endif
 546 static struct svc_version *     nlmsvc_version[] = {
 547         [1] = &nlmsvc_version1,
 548         [3] = &nlmsvc_version3,
 549 #ifdef CONFIG_LOCKD_V4
 550         [4] = &nlmsvc_version4,
 551 #endif
 552 };
 553
 554 static struct svc_stat          nlmsvc_stats;
 555
 556 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 557 static struct svc_program       nlmsvc_program = {
 558         .pg_prog                = NLM_PROGRAM,          /* program number */
 559         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 560         .pg_vers                = nlmsvc_version,       /* version table */
 561         .pg_name                = "lockd",              /* service name */
 562         .pg_class               = "nfsd",               /* share authentication with nfsd */
 563         .pg_stats               = &nlmsvc_stats,        /* stats table */
 564         .pg_authenticate = &lockd_authenticate  /* export authentication */
 565 };