fs/lockd/svcproc.c

   1 /*
   2  * linux/fs/lockd/svcproc.c
   3  *
   4  * Lockd server procedures. We don't implement the NLM_*_RES
   5  * procedures because we don't use the async procedures.
   6  *
   7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/time.h>
  12 #include <linux/slab.h>
  13 #include <linux/smp_lock.h>
  14 #include <linux/lockd/lockd.h>
  15 #include <linux/lockd/share.h>
  16
  17 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  18
  19 #ifdef CONFIG_LOCKD_V4
  20 static __be32
  21 cast_to_nlm(__be32 status, u32 vers)
  22 {
  23         /* Note: status is assumed to be in network byte order !!! */
  24         if (vers != 4){
  25                 switch (status) {
  26                 case nlm_granted:
  27                 case nlm_lck_denied:
  28                 case nlm_lck_denied_nolocks:
  29                 case nlm_lck_blocked:
  30                 case nlm_lck_denied_grace_period:
  31                 case nlm_drop_reply:
  32                         break;
  33                 case nlm4_deadlock:
  34                         status = nlm_lck_denied;
  35                         break;
  36                 default:
  37                         status = nlm_lck_denied_nolocks;
  38                 }
  39         }
  40
  41         return (status);
  42 }
  43 #define cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
  44 #else
  45 #define cast_status(status) (status)
  46 #endif
  47
  48 /*
  49  * Obtain client and file from arguments
  50  */
  51 static __be32
  52 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  53                         struct nlm_host **hostp, struct nlm_file **filp)
  54 {
  55         struct nlm_host         *host = NULL;
  56         struct nlm_file         *file = NULL;
  57         struct nlm_lock         *lock = &argp->lock;
  58         __be32                  error = 0;
  59
  60         /* nfsd callbacks must have been installed for this procedure */
  61         if (!nlmsvc_ops)
  62                 return nlm_lck_denied_nolocks;
  63
  64         /* Obtain host handle */
  65         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  66          || (argp->monitor && nsm_monitor(host) < 0))
  67                 goto no_locks;
  68         *hostp = host;
  69
  70         /* Obtain file pointer. Not used by FREE_ALL call. */
  71         if (filp != NULL) {
  72                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  73                         goto no_locks;
  74                 *filp = file;
  75
  76                 /* Set up the missing parts of the file_lock structure */
  77                 lock->fl.fl_file  = file->f_file;
  78                 lock->fl.fl_owner = (fl_owner_t) host;
  79                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  80         }
  81
  82         return 0;
  83
  84 no_locks:
  85         nlm_release_host(host);
  86         if (error)
  87                 return error;
  88         return nlm_lck_denied_nolocks;
  89 }
  90
  91 /*
  92  * NULL: Test for presence of service
  93  */
  94 static __be32
  95 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  96 {
  97         dprintk("lockd: NULL          called\n");
  98         return rpc_success;
  99 }
 100
 101 /*
 102  * TEST: Check for conflicting lock
 103  */
 104 static __be32
 105 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
 106                                          struct nlm_res  *resp)
 107 {
 108         struct nlm_host *host;
 109         struct nlm_file *file;
 110         __be32 rc = rpc_success;
 111
 112         dprintk("lockd: TEST          called\n");
 113         resp->cookie = argp->cookie;
 114
 115         /* Obtain client and file */
 116         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 117                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 118
 119         /* Now check for conflicting locks */
 120         resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
 121         if (resp->status == nlm_drop_reply)
 122                 rc = rpc_drop_reply;
 123         else
 124                 dprintk("lockd: TEST          status %d vers %d\n",
 125                         ntohl(resp->status), rqstp->rq_vers);
 126
 127         nlm_release_host(host);
 128         nlm_release_file(file);
 129         return rc;
 130 }
 131
 132 static __be32
 133 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 134                                          struct nlm_res  *resp)
 135 {
 136         struct nlm_host *host;
 137         struct nlm_file *file;
 138         __be32 rc = rpc_success;
 139
 140         dprintk("lockd: LOCK          called\n");
 141
 142         resp->cookie = argp->cookie;
 143
 144         /* Obtain client and file */
 145         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 146                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 147
 148 #if 0
 149         /* If supplied state doesn't match current state, we assume it's
 150          * an old request that time-warped somehow. Any error return would
 151          * do in this case because it's irrelevant anyway.
 152          *
 153          * NB: We don't retrieve the remote host's state yet.
 154          */
 155         if (host->h_nsmstate && host->h_nsmstate != argp->state) {
 156                 resp->status = nlm_lck_denied_nolocks;
 157         } else
 158 #endif
 159
 160         /* Now try to lock the file */
 161         resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 162                                                argp->block, &argp->cookie,
 163                                                argp->reclaim));
 164         if (resp->status == nlm_drop_reply)
 165                 rc = rpc_drop_reply;
 166         else
 167                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 168
 169         nlm_release_host(host);
 170         nlm_release_file(file);
 171         return rc;
 172 }
 173
 174 static __be32
 175 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 176                                            struct nlm_res  *resp)
 177 {
 178         struct nlm_host *host;
 179         struct nlm_file *file;
 180
 181         dprintk("lockd: CANCEL        called\n");
 182
 183         resp->cookie = argp->cookie;
 184
 185         /* Don't accept requests during grace period */
 186         if (locks_in_grace()) {
 187                 resp->status = nlm_lck_denied_grace_period;
 188                 return rpc_success;
 189         }
 190
 191         /* Obtain client and file */
 192         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 193                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 194
 195         /* Try to cancel request. */
 196         resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
 197
 198         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 199         nlm_release_host(host);
 200         nlm_release_file(file);
 201         return rpc_success;
 202 }
 203
 204 /*
 205  * UNLOCK: release a lock
 206  */
 207 static __be32
 208 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 209                                            struct nlm_res  *resp)
 210 {
 211         struct nlm_host *host;
 212         struct nlm_file *file;
 213
 214         dprintk("lockd: UNLOCK        called\n");
 215
 216         resp->cookie = argp->cookie;
 217
 218         /* Don't accept new lock requests during grace period */
 219         if (locks_in_grace()) {
 220                 resp->status = nlm_lck_denied_grace_period;
 221                 return rpc_success;
 222         }
 223
 224         /* Obtain client and file */
 225         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 226                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 227
 228         /* Now try to remove the lock */
 229         resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
 230
 231         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 232         nlm_release_host(host);
 233         nlm_release_file(file);
 234         return rpc_success;
 235 }
 236
 237 /*
 238  * GRANTED: A server calls us to tell that a process' lock request
 239  * was granted
 240  */
 241 static __be32
 242 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 243                                             struct nlm_res  *resp)
 244 {
 245         resp->cookie = argp->cookie;
 246
 247         dprintk("lockd: GRANTED       called\n");
 248         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 249         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 250         return rpc_success;
 251 }
 252
 253 /*
 254  * This is the generic lockd callback for async RPC calls
 255  */
 256 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 257 {
 258         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 259                         -task->tk_status);
 260 }
 261
 262 static void nlmsvc_callback_release(void *data)
 263 {
 264         lock_kernel();
 265         nlm_release_call(data);
 266         unlock_kernel();
 267 }
 268
 269 static const struct rpc_call_ops nlmsvc_callback_ops = {
 270         .rpc_call_done = nlmsvc_callback_exit,
 271         .rpc_release = nlmsvc_callback_release,
 272 };
 273
 274 /*
 275  * `Async' versions of the above service routines. They aren't really,
 276  * because we send the callback before the reply proper. I hope this
 277  * doesn't break any clients.
 278  */
 279 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 280                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 281 {
 282         struct nlm_host *host;
 283         struct nlm_rqst *call;
 284         __be32 stat;
 285
 286         host = nlmsvc_lookup_host(rqstp,
 287                                   argp->lock.caller,
 288                                   argp->lock.len);
 289         if (host == NULL)
 290                 return rpc_system_err;
 291
 292         call = nlm_alloc_call(host);
 293         if (call == NULL)
 294                 return rpc_system_err;
 295
 296         stat = func(rqstp, argp, &call->a_res);
 297         if (stat != 0) {
 298                 nlm_release_call(call);
 299                 return stat;
 300         }
 301
 302         call->a_flags = RPC_TASK_ASYNC;
 303         if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 304                 return rpc_system_err;
 305         return rpc_success;
 306 }
 307
 308 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 309                                              void            *resp)
 310 {
 311         dprintk("lockd: TEST_MSG      called\n");
 312         return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
 313 }
 314
 315 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 316                                              void            *resp)
 317 {
 318         dprintk("lockd: LOCK_MSG      called\n");
 319         return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
 320 }
 321
 322 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 323                                                void            *resp)
 324 {
 325         dprintk("lockd: CANCEL_MSG    called\n");
 326         return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
 327 }
 328
 329 static __be32
 330 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 331                                                void            *resp)
 332 {
 333         dprintk("lockd: UNLOCK_MSG    called\n");
 334         return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
 335 }
 336
 337 static __be32
 338 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 339                                                 void            *resp)
 340 {
 341         dprintk("lockd: GRANTED_MSG   called\n");
 342         return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
 343 }
 344
 345 /*
 346  * SHARE: create a DOS share or alter existing share.
 347  */
 348 static __be32
 349 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 350                                           struct nlm_res  *resp)
 351 {
 352         struct nlm_host *host;
 353         struct nlm_file *file;
 354
 355         dprintk("lockd: SHARE         called\n");
 356
 357         resp->cookie = argp->cookie;
 358
 359         /* Don't accept new lock requests during grace period */
 360         if (locks_in_grace() && !argp->reclaim) {
 361                 resp->status = nlm_lck_denied_grace_period;
 362                 return rpc_success;
 363         }
 364
 365         /* Obtain client and file */
 366         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 367                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 368
 369         /* Now try to create the share */
 370         resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 371
 372         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 373         nlm_release_host(host);
 374         nlm_release_file(file);
 375         return rpc_success;
 376 }
 377
 378 /*
 379  * UNSHARE: Release a DOS share.
 380  */
 381 static __be32
 382 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 383                                             struct nlm_res  *resp)
 384 {
 385         struct nlm_host *host;
 386         struct nlm_file *file;
 387
 388         dprintk("lockd: UNSHARE       called\n");
 389
 390         resp->cookie = argp->cookie;
 391
 392         /* Don't accept requests during grace period */
 393         if (locks_in_grace()) {
 394                 resp->status = nlm_lck_denied_grace_period;
 395                 return rpc_success;
 396         }
 397
 398         /* Obtain client and file */
 399         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 400                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 401
 402         /* Now try to unshare the file */
 403         resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 404
 405         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 406         nlm_release_host(host);
 407         nlm_release_file(file);
 408         return rpc_success;
 409 }
 410
 411 /*
 412  * NM_LOCK: Create an unmonitored lock
 413  */
 414 static __be32
 415 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 416                                             struct nlm_res  *resp)
 417 {
 418         dprintk("lockd: NM_LOCK       called\n");
 419
 420         argp->monitor = 0;              /* just clean the monitor flag */
 421         return nlmsvc_proc_lock(rqstp, argp, resp);
 422 }
 423
 424 /*
 425  * FREE_ALL: Release all locks and shares held by client
 426  */
 427 static __be32
 428 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 429                                              void            *resp)
 430 {
 431         struct nlm_host *host;
 432
 433         /* Obtain client */
 434         if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 435                 return rpc_success;
 436
 437         nlmsvc_free_host_resources(host);
 438         nlm_release_host(host);
 439         return rpc_success;
 440 }
 441
 442 /*
 443  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 444  */
 445 static __be32
 446 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 447                                               void              *resp)
 448 {
 449         dprintk("lockd: SM_NOTIFY     called\n");
 450
 451         if (!nlm_privileged_requester(rqstp)) {
 452                 char buf[RPC_MAX_ADDRBUFLEN];
 453                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 454                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 455                 return rpc_system_err;
 456         }
 457
 458         nlm_host_rebooted(argp);
 459         return rpc_success;
 460 }
 461
 462 /*
 463  * client sent a GRANTED_RES, let's remove the associated block
 464  */
 465 static __be32
 466 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 467                                                 void            *resp)
 468 {
 469         if (!nlmsvc_ops)
 470                 return rpc_success;
 471
 472         dprintk("lockd: GRANTED_RES   called\n");
 473
 474         nlmsvc_grant_reply(&argp->cookie, argp->status);
 475         return rpc_success;
 476 }
 477
 478 /*
 479  * NLM Server procedures.
 480  */
 481
 482 #define nlmsvc_encode_norep     nlmsvc_encode_void
 483 #define nlmsvc_decode_norep     nlmsvc_decode_void
 484 #define nlmsvc_decode_testres   nlmsvc_decode_void
 485 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 486 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 487 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 488 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 489
 490 #define nlmsvc_proc_none        nlmsvc_proc_null
 491 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 492 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 493 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 494 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 495
 496 struct nlm_void                 { int dummy; };
 497
 498 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 499  { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 500    .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 501    .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 502    .pc_release  = NULL,                                 \
 503    .pc_argsize  = sizeof(struct nlm_##argt),            \
 504    .pc_ressize  = sizeof(struct nlm_##rest),            \
 505    .pc_xdrressize = respsize,                           \
 506  }
 507
 508 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 509 #define St      1                               /* status */
 510 #define No      (1+1024/4)                      /* Net Obj */
 511 #define Rg      2                               /* range - offset + size */
 512
 513 struct svc_procedure            nlmsvc_procedures[] = {
 514   PROC(null,            void,           void,           void,   void, 1),
 515   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 516   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 517   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 518   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 519   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 520   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 521   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 522   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 523   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 524   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 525   PROC(test_res,        testres,        norep,          res,    void, 1),
 526   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 527   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 528   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 529   PROC(granted_res,     res,            norep,          res,    void, 1),
 530   /* statd callback */
 531   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 532   PROC(none,            void,           void,           void,   void, 1),
 533   PROC(none,            void,           void,           void,   void, 1),
 534   PROC(none,            void,           void,           void,   void, 1),
 535   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 536   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 537   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 538   PROC(free_all,        notify,         void,           args,   void, 0),
 539
 540 };