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/kthread.h>
  29 #include <linux/freezer.h>
  30
  31 #include <linux/sunrpc/types.h>
  32 #include <linux/sunrpc/stats.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/svc.h>
  35 #include <linux/sunrpc/svcsock.h>
  36 #include <net/ip.h>
  37 #include <linux/lockd/lockd.h>
  38 #include <linux/lockd/sm_inter.h>
  39 #include <linux/nfs.h>
  40
  41 #define NLMDBG_FACILITY         NLMDBG_SVC
  42 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  43 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  44
  45 static struct svc_program       nlmsvc_program;
  46
  47 struct nlmsvc_binding *         nlmsvc_ops;
  48 EXPORT_SYMBOL(nlmsvc_ops);
  49
  50 static DEFINE_MUTEX(nlmsvc_mutex);
  51 static unsigned int             nlmsvc_users;
  52 static struct task_struct       *nlmsvc_task;
  53 static struct svc_rqst          *nlmsvc_rqst;
  54 int                             nlmsvc_grace_period;
  55 unsigned long                   nlmsvc_timeout;
  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 int                             nsm_use_hostnames = 0;
  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 #ifdef CONFIG_SYSCTL
  76 static struct ctl_table_header * nlm_sysctl_table;
  77 #endif
  78
  79 static unsigned long get_lockd_grace_period(void)
  80 {
  81         /* Note: nlm_timeout should always be nonzero */
  82         if (nlm_grace_period)
  83                 return roundup(nlm_grace_period, nlm_timeout) * HZ;
  84         else
  85                 return nlm_timeout * 5 * HZ;
  86 }
  87
  88 unsigned long get_nfs_grace_period(void)
  89 {
  90         unsigned long lockdgrace = get_lockd_grace_period();
  91         unsigned long nfsdgrace = 0;
  92
  93         if (nlmsvc_ops)
  94                 nfsdgrace = nlmsvc_ops->get_grace_period();
  95
  96         return max(lockdgrace, nfsdgrace);
  97 }
  98 EXPORT_SYMBOL(get_nfs_grace_period);
  99
 100 static void grace_ender(struct work_struct *not_used)
 101 {
 102         nlmsvc_grace_period = 0;
 103 }
 104
 105 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
 106
 107 static void set_grace_period(void)
 108 {
 109         unsigned long grace_period = get_nfs_grace_period() + jiffies;
 110
 111         nlmsvc_grace_period = 1;
 112         cancel_delayed_work_sync(&grace_period_end);
 113         schedule_delayed_work(&grace_period_end, grace_period);
 114 }
 115
 116 /*
 117  * This is the lockd kernel thread
 118  */
 119 static int
 120 lockd(void *vrqstp)
 121 {
 122         int             err = 0, preverr = 0;
 123         struct svc_rqst *rqstp = vrqstp;
 124
 125         /* try_to_freeze() is called from svc_recv() */
 126         set_freezable();
 127
 128         /* Allow SIGKILL to tell lockd to drop all of its locks */
 129         allow_signal(SIGKILL);
 130
 131         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 132
 133         /*
 134          * FIXME: it would be nice if lockd didn't spend its entire life
 135          * running under the BKL. At the very least, it would be good to
 136          * have someone clarify what it's intended to protect here. I've
 137          * seen some handwavy posts about posix locking needing to be
 138          * done under the BKL, but it's far from clear.
 139          */
 140         lock_kernel();
 141
 142         if (!nlm_timeout)
 143                 nlm_timeout = LOCKD_DFLT_TIMEO;
 144         nlmsvc_timeout = nlm_timeout * HZ;
 145
 146         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.
 151          */
 152         while (!kthread_should_stop()) {
 153                 long timeout = MAX_SCHEDULE_TIMEOUT;
 154                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 155
 156                 if (signalled()) {
 157                         flush_signals(current);
 158                         if (nlmsvc_ops) {
 159                                 nlmsvc_invalidate_all();
 160                                 set_grace_period();
 161                         }
 162                         continue;
 163                 }
 164
 165                 timeout = nlmsvc_retry_blocked();
 166
 167                 /*
 168                  * Find a socket with data available and call its
 169                  * recvfrom routine.
 170                  */
 171                 err = svc_recv(rqstp, timeout);
 172                 if (err == -EAGAIN || err == -EINTR) {
 173                         preverr = err;
 174                         continue;
 175                 }
 176                 if (err < 0) {
 177                         if (err != preverr) {
 178                                 printk(KERN_WARNING "%s: unexpected error "
 179                                         "from svc_recv (%d)\n", __func__, err);
 180                                 preverr = err;
 181                         }
 182                         schedule_timeout_interruptible(HZ);
 183                         continue;
 184                 }
 185                 preverr = err;
 186
 187                 dprintk("lockd: request from %s\n",
 188                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 189
 190                 svc_process(rqstp);
 191         }
 192         flush_signals(current);
 193         cancel_delayed_work_sync(&grace_period_end);
 194         if (nlmsvc_ops)
 195                 nlmsvc_invalidate_all();
 196         nlm_shutdown_hosts();
 197         unlock_kernel();
 198         return 0;
 199 }
 200
 201 /*
 202  * Make any sockets that are needed but not present.
 203  * If nlm_udpport or nlm_tcpport were set as module
 204  * options, make those sockets unconditionally
 205  */
 206 static int make_socks(struct svc_serv *serv, int proto)
 207 {
 208         static int warned;
 209         struct svc_xprt *xprt;
 210         int err = 0;
 211
 212         if (proto == IPPROTO_UDP || nlm_udpport) {
 213                 xprt = svc_find_xprt(serv, "udp", 0, 0);
 214                 if (!xprt)
 215                         err = svc_create_xprt(serv, "udp", nlm_udpport,
 216                                               SVC_SOCK_DEFAULTS);
 217                 else
 218                         svc_xprt_put(xprt);
 219         }
 220         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
 221                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
 222                 if (!xprt)
 223                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
 224                                               SVC_SOCK_DEFAULTS);
 225                 else
 226                         svc_xprt_put(xprt);
 227         }
 228         if (err >= 0) {
 229                 warned = 0;
 230                 err = 0;
 231         } else if (warned++ == 0)
 232                 printk(KERN_WARNING
 233                        "lockd_up: makesock failed, error=%d\n", err);
 234         return err;
 235 }
 236
 237 /*
 238  * Bring up the lockd process if it's not already up.
 239  */
 240 int
 241 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 242 {
 243         struct svc_serv *serv;
 244         int             error = 0;
 245
 246         mutex_lock(&nlmsvc_mutex);
 247         /*
 248          * Check whether we're already up and running.
 249          */
 250         if (nlmsvc_rqst) {
 251                 if (proto)
 252                         error = make_socks(nlmsvc_rqst->rq_server, proto);
 253                 goto out;
 254         }
 255
 256         /*
 257          * Sanity check: if there's no pid,
 258          * we should be the first user ...
 259          */
 260         if (nlmsvc_users)
 261                 printk(KERN_WARNING
 262                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 263
 264         error = -ENOMEM;
 265         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
 266         if (!serv) {
 267                 printk(KERN_WARNING "lockd_up: create service failed\n");
 268                 goto out;
 269         }
 270
 271         if ((error = make_socks(serv, proto)) < 0)
 272                 goto destroy_and_out;
 273
 274         /*
 275          * Create the kernel thread and wait for it to start.
 276          */
 277         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
 278         if (IS_ERR(nlmsvc_rqst)) {
 279                 error = PTR_ERR(nlmsvc_rqst);
 280                 nlmsvc_rqst = NULL;
 281                 printk(KERN_WARNING
 282                         "lockd_up: svc_rqst allocation failed, error=%d\n",
 283                         error);
 284                 goto destroy_and_out;
 285         }
 286
 287         svc_sock_update_bufs(serv);
 288
 289         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
 290         if (IS_ERR(nlmsvc_task)) {
 291                 error = PTR_ERR(nlmsvc_task);
 292                 svc_exit_thread(nlmsvc_rqst);
 293                 nlmsvc_task = NULL;
 294                 nlmsvc_rqst = NULL;
 295                 printk(KERN_WARNING
 296                         "lockd_up: kthread_run failed, error=%d\n", error);
 297                 goto destroy_and_out;
 298         }
 299
 300         /*
 301          * Note: svc_serv structures have an initial use count of 1,
 302          * so we exit through here on both success and failure.
 303          */
 304 destroy_and_out:
 305         svc_destroy(serv);
 306 out:
 307         if (!error)
 308                 nlmsvc_users++;
 309         mutex_unlock(&nlmsvc_mutex);
 310         return error;
 311 }
 312 EXPORT_SYMBOL(lockd_up);
 313
 314 /*
 315  * Decrement the user count and bring down lockd if we're the last.
 316  */
 317 void
 318 lockd_down(void)
 319 {
 320         mutex_lock(&nlmsvc_mutex);
 321         if (nlmsvc_users) {
 322                 if (--nlmsvc_users)
 323                         goto out;
 324         } else {
 325                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
 326                         nlmsvc_task);
 327                 BUG();
 328         }
 329
 330         if (!nlmsvc_task) {
 331                 printk(KERN_ERR "lockd_down: no lockd running.\n");
 332                 BUG();
 333         }
 334         kthread_stop(nlmsvc_task);
 335         svc_exit_thread(nlmsvc_rqst);
 336         nlmsvc_task = NULL;
 337         nlmsvc_rqst = NULL;
 338 out:
 339         mutex_unlock(&nlmsvc_mutex);
 340 }
 341 EXPORT_SYMBOL(lockd_down);
 342
 343 #ifdef CONFIG_SYSCTL
 344
 345 /*
 346  * Sysctl parameters (same as module parameters, different interface).
 347  */
 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(unsigned long),
 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(unsigned long),
 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         {
 391                 .ctl_name       = CTL_UNNUMBERED,
 392                 .procname       = "nsm_use_hostnames",
 393                 .data           = &nsm_use_hostnames,
 394                 .maxlen         = sizeof(int),
 395                 .mode           = 0644,
 396                 .proc_handler   = &proc_dointvec,
 397         },
 398         {
 399                 .ctl_name       = CTL_UNNUMBERED,
 400                 .procname       = "nsm_local_state",
 401                 .data           = &nsm_local_state,
 402                 .maxlen         = sizeof(int),
 403                 .mode           = 0644,
 404                 .proc_handler   = &proc_dointvec,
 405         },
 406         { .ctl_name = 0 }
 407 };
 408
 409 static ctl_table nlm_sysctl_dir[] = {
 410         {
 411                 .ctl_name       = CTL_UNNUMBERED,
 412                 .procname       = "nfs",
 413                 .mode           = 0555,
 414                 .child          = nlm_sysctls,
 415         },
 416         { .ctl_name = 0 }
 417 };
 418
 419 static ctl_table nlm_sysctl_root[] = {
 420         {
 421                 .ctl_name       = CTL_FS,
 422                 .procname       = "fs",
 423                 .mode           = 0555,
 424                 .child          = nlm_sysctl_dir,
 425         },
 426         { .ctl_name = 0 }
 427 };
 428
 429 #endif  /* CONFIG_SYSCTL */
 430
 431 /*
 432  * Module (and sysfs) parameters.
 433  */
 434
 435 #define param_set_min_max(name, type, which_strtol, min, max)           \
 436 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 437 {                                                                       \
 438         char *endp;                                                     \
 439         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 440         if (endp == val || *endp || num < (min) || num > (max))         \
 441                 return -EINVAL;                                         \
 442         *((int *) kp->arg) = num;                                       \
 443         return 0;                                                       \
 444 }
 445
 446 static inline int is_callback(u32 proc)
 447 {
 448         return proc == NLMPROC_GRANTED
 449                 || proc == NLMPROC_GRANTED_MSG
 450                 || proc == NLMPROC_TEST_RES
 451                 || proc == NLMPROC_LOCK_RES
 452                 || proc == NLMPROC_CANCEL_RES
 453                 || proc == NLMPROC_UNLOCK_RES
 454                 || proc == NLMPROC_NSM_NOTIFY;
 455 }
 456
 457
 458 static int lockd_authenticate(struct svc_rqst *rqstp)
 459 {
 460         rqstp->rq_client = NULL;
 461         switch (rqstp->rq_authop->flavour) {
 462                 case RPC_AUTH_NULL:
 463                 case RPC_AUTH_UNIX:
 464                         if (rqstp->rq_proc == 0)
 465                                 return SVC_OK;
 466                         if (is_callback(rqstp->rq_proc)) {
 467                                 /* Leave it to individual procedures to
 468                                  * call nlmsvc_lookup_host(rqstp)
 469                                  */
 470                                 return SVC_OK;
 471                         }
 472                         return svc_set_client(rqstp);
 473         }
 474         return SVC_DENIED;
 475 }
 476
 477
 478 param_set_min_max(port, int, simple_strtol, 0, 65535)
 479 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 480                   nlm_grace_period_min, nlm_grace_period_max)
 481 param_set_min_max(timeout, unsigned long, simple_strtoul,
 482                   nlm_timeout_min, nlm_timeout_max)
 483
 484 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 485 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 486 MODULE_LICENSE("GPL");
 487
 488 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 489                   &nlm_grace_period, 0644);
 490 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 491                   &nlm_timeout, 0644);
 492 module_param_call(nlm_udpport, param_set_port, param_get_int,
 493                   &nlm_udpport, 0644);
 494 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 495                   &nlm_tcpport, 0644);
 496 module_param(nsm_use_hostnames, bool, 0644);
 497
 498 /*
 499  * Initialising and terminating the module.
 500  */
 501
 502 static int __init init_nlm(void)
 503 {
 504 #ifdef CONFIG_SYSCTL
 505         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 506         return nlm_sysctl_table ? 0 : -ENOMEM;
 507 #else
 508         return 0;
 509 #endif
 510 }
 511
 512 static void __exit exit_nlm(void)
 513 {
 514         /* FIXME: delete all NLM clients */
 515         nlm_shutdown_hosts();
 516 #ifdef CONFIG_SYSCTL
 517         unregister_sysctl_table(nlm_sysctl_table);
 518 #endif
 519 }
 520
 521 module_init(init_nlm);
 522 module_exit(exit_nlm);
 523
 524 /*
 525  * Define NLM program and procedures
 526  */
 527 static struct svc_version       nlmsvc_version1 = {
 528                 .vs_vers        = 1,
 529                 .vs_nproc       = 17,
 530                 .vs_proc        = nlmsvc_procedures,
 531                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 532 };
 533 static struct svc_version       nlmsvc_version3 = {
 534                 .vs_vers        = 3,
 535                 .vs_nproc       = 24,
 536                 .vs_proc        = nlmsvc_procedures,
 537                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 538 };
 539 #ifdef CONFIG_LOCKD_V4
 540 static struct svc_version       nlmsvc_version4 = {
 541                 .vs_vers        = 4,
 542                 .vs_nproc       = 24,
 543                 .vs_proc        = nlmsvc_procedures4,
 544                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 545 };
 546 #endif
 547 static struct svc_version *     nlmsvc_version[] = {
 548         [1] = &nlmsvc_version1,
 549         [3] = &nlmsvc_version3,
 550 #ifdef CONFIG_LOCKD_V4
 551         [4] = &nlmsvc_version4,
 552 #endif
 553 };
 554
 555 static struct svc_stat          nlmsvc_stats;
 556
 557 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 558 static struct svc_program       nlmsvc_program = {
 559         .pg_prog                = NLM_PROGRAM,          /* program number */
 560         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 561         .pg_vers                = nlmsvc_version,       /* version table */
 562         .pg_name                = "lockd",              /* service name */
 563         .pg_class               = "nfsd",               /* share authentication with nfsd */
 564         .pg_stats               = &nlmsvc_stats,        /* stats table */
 565         .pg_authenticate = &lockd_authenticate  /* export authentication */
 566 };