release/src-rt-6.x.4708/linux/linux-2.6.36/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/smp_lock.h>
  13 #include <linux/lockd/lockd.h>
  14 #include <linux/lockd/share.h>
  15
  16 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  17
  18 #ifdef CONFIG_LOCKD_V4
  19 static __be32
  20 cast_to_nlm(__be32 status, u32 vers)
  21 {
  22         /* Note: status is assumed to be in network byte order !!! */
  23         if (vers != 4){
  24                 switch (status) {
  25                 case nlm_granted:
  26                 case nlm_lck_denied:
  27                 case nlm_lck_denied_nolocks:
  28                 case nlm_lck_blocked:
  29                 case nlm_lck_denied_grace_period:
  30                 case nlm_drop_reply:
  31                         break;
  32                 case nlm4_deadlock:
  33                         status = nlm_lck_denied;
  34                         break;
  35                 default:
  36                         status = nlm_lck_denied_nolocks;
  37                 }
  38         }
  39
  40         return (status);
  41 }
  42 #define cast_status(status) (cast_to_nlm(status, rqstp->rq_vers))
  43 #else
  44 #define cast_status(status) (status)
  45 #endif
  46
  47 /*
  48  * Obtain client and file from arguments
  49  */
  50 static __be32
  51 nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
  52                         struct nlm_host **hostp, struct nlm_file **filp)
  53 {
  54         struct nlm_host         *host = NULL;
  55         struct nlm_file         *file = NULL;
  56         struct nlm_lock         *lock = &argp->lock;
  57         __be32                  error = 0;
  58
  59         /* nfsd callbacks must have been installed for this procedure */
  60         if (!nlmsvc_ops)
  61                 return nlm_lck_denied_nolocks;
  62
  63         /* Obtain host handle */
  64         if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
  65          || (argp->monitor && nsm_monitor(host) < 0))
  66                 goto no_locks;
  67         *hostp = host;
  68
  69         /* Obtain file pointer. Not used by FREE_ALL call. */
  70         if (filp != NULL) {
  71                 if ((error = nlm_lookup_file(rqstp, &file, &lock->fh)) != 0)
  72                         goto no_locks;
  73                 *filp = file;
  74
  75                 /* Set up the missing parts of the file_lock structure */
  76                 lock->fl.fl_file  = file->f_file;
  77                 lock->fl.fl_owner = (fl_owner_t) host;
  78                 lock->fl.fl_lmops = &nlmsvc_lock_operations;
  79         }
  80
  81         return 0;
  82
  83 no_locks:
  84         nlm_release_host(host);
  85         if (error)
  86                 return error;
  87         return nlm_lck_denied_nolocks;
  88 }
  89
  90 /*
  91  * NULL: Test for presence of service
  92  */
  93 static __be32
  94 nlmsvc_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
  95 {
  96         dprintk("lockd: NULL          called\n");
  97         return rpc_success;
  98 }
  99
 100 /*
 101  * TEST: Check for conflicting lock
 102  */
 103 static __be32
 104 nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
 105                                          struct nlm_res  *resp)
 106 {
 107         struct nlm_host *host;
 108         struct nlm_file *file;
 109         __be32 rc = rpc_success;
 110
 111         dprintk("lockd: TEST          called\n");
 112         resp->cookie = argp->cookie;
 113
 114         /* Obtain client and file */
 115         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 116                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 117
 118         /* Now check for conflicting locks */
 119         resp->status = cast_status(nlmsvc_testlock(rqstp, file, host, &argp->lock, &resp->lock, &resp->cookie));
 120         if (resp->status == nlm_drop_reply)
 121                 rc = rpc_drop_reply;
 122         else
 123                 dprintk("lockd: TEST          status %d vers %d\n",
 124                         ntohl(resp->status), rqstp->rq_vers);
 125
 126         nlm_release_host(host);
 127         nlm_release_file(file);
 128         return rc;
 129 }
 130
 131 static __be32
 132 nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 133                                          struct nlm_res  *resp)
 134 {
 135         struct nlm_host *host;
 136         struct nlm_file *file;
 137         __be32 rc = rpc_success;
 138
 139         dprintk("lockd: LOCK          called\n");
 140
 141         resp->cookie = argp->cookie;
 142
 143         /* Obtain client and file */
 144         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 145                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 146
 147
 148         /* Now try to lock the file */
 149         resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
 150                                                argp->block, &argp->cookie,
 151                                                argp->reclaim));
 152         if (resp->status == nlm_drop_reply)
 153                 rc = rpc_drop_reply;
 154         else
 155                 dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
 156
 157         nlm_release_host(host);
 158         nlm_release_file(file);
 159         return rc;
 160 }
 161
 162 static __be32
 163 nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct nlm_args *argp,
 164                                            struct nlm_res  *resp)
 165 {
 166         struct nlm_host *host;
 167         struct nlm_file *file;
 168
 169         dprintk("lockd: CANCEL        called\n");
 170
 171         resp->cookie = argp->cookie;
 172
 173         /* Don't accept requests during grace period */
 174         if (locks_in_grace()) {
 175                 resp->status = nlm_lck_denied_grace_period;
 176                 return rpc_success;
 177         }
 178
 179         /* Obtain client and file */
 180         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 181                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 182
 183         /* Try to cancel request. */
 184         resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
 185
 186         dprintk("lockd: CANCEL        status %d\n", ntohl(resp->status));
 187         nlm_release_host(host);
 188         nlm_release_file(file);
 189         return rpc_success;
 190 }
 191
 192 /*
 193  * UNLOCK: release a lock
 194  */
 195 static __be32
 196 nlmsvc_proc_unlock(struct svc_rqst *rqstp, struct nlm_args *argp,
 197                                            struct nlm_res  *resp)
 198 {
 199         struct nlm_host *host;
 200         struct nlm_file *file;
 201
 202         dprintk("lockd: UNLOCK        called\n");
 203
 204         resp->cookie = argp->cookie;
 205
 206         /* Don't accept new lock requests during grace period */
 207         if (locks_in_grace()) {
 208                 resp->status = nlm_lck_denied_grace_period;
 209                 return rpc_success;
 210         }
 211
 212         /* Obtain client and file */
 213         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 214                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 215
 216         /* Now try to remove the lock */
 217         resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
 218
 219         dprintk("lockd: UNLOCK        status %d\n", ntohl(resp->status));
 220         nlm_release_host(host);
 221         nlm_release_file(file);
 222         return rpc_success;
 223 }
 224
 225 /*
 226  * GRANTED: A server calls us to tell that a process' lock request
 227  * was granted
 228  */
 229 static __be32
 230 nlmsvc_proc_granted(struct svc_rqst *rqstp, struct nlm_args *argp,
 231                                             struct nlm_res  *resp)
 232 {
 233         resp->cookie = argp->cookie;
 234
 235         dprintk("lockd: GRANTED       called\n");
 236         resp->status = nlmclnt_grant(svc_addr(rqstp), &argp->lock);
 237         dprintk("lockd: GRANTED       status %d\n", ntohl(resp->status));
 238         return rpc_success;
 239 }
 240
 241 /*
 242  * This is the generic lockd callback for async RPC calls
 243  */
 244 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 245 {
 246         dprintk("lockd: %5u callback returned %d\n", task->tk_pid,
 247                         -task->tk_status);
 248 }
 249
 250 static void nlmsvc_callback_release(void *data)
 251 {
 252         lock_kernel();
 253         nlm_release_call(data);
 254         unlock_kernel();
 255 }
 256
 257 static const struct rpc_call_ops nlmsvc_callback_ops = {
 258         .rpc_call_done = nlmsvc_callback_exit,
 259         .rpc_release = nlmsvc_callback_release,
 260 };
 261
 262 /*
 263  * `Async' versions of the above service routines. They aren't really,
 264  * because we send the callback before the reply proper. I hope this
 265  * doesn't break any clients.
 266  */
 267 static __be32 nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_args *argp,
 268                 __be32 (*func)(struct svc_rqst *, struct nlm_args *, struct nlm_res  *))
 269 {
 270         struct nlm_host *host;
 271         struct nlm_rqst *call;
 272         __be32 stat;
 273
 274         host = nlmsvc_lookup_host(rqstp,
 275                                   argp->lock.caller,
 276                                   argp->lock.len);
 277         if (host == NULL)
 278                 return rpc_system_err;
 279
 280         call = nlm_alloc_call(host);
 281         if (call == NULL)
 282                 return rpc_system_err;
 283
 284         stat = func(rqstp, argp, &call->a_res);
 285         if (stat != 0) {
 286                 nlm_release_call(call);
 287                 return stat;
 288         }
 289
 290         call->a_flags = RPC_TASK_ASYNC;
 291         if (nlm_async_reply(call, proc, &nlmsvc_callback_ops) < 0)
 292                 return rpc_system_err;
 293         return rpc_success;
 294 }
 295
 296 static __be32 nlmsvc_proc_test_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 297                                              void            *resp)
 298 {
 299         dprintk("lockd: TEST_MSG      called\n");
 300         return nlmsvc_callback(rqstp, NLMPROC_TEST_RES, argp, nlmsvc_proc_test);
 301 }
 302
 303 static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 304                                              void            *resp)
 305 {
 306         dprintk("lockd: LOCK_MSG      called\n");
 307         return nlmsvc_callback(rqstp, NLMPROC_LOCK_RES, argp, nlmsvc_proc_lock);
 308 }
 309
 310 static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 311                                                void            *resp)
 312 {
 313         dprintk("lockd: CANCEL_MSG    called\n");
 314         return nlmsvc_callback(rqstp, NLMPROC_CANCEL_RES, argp, nlmsvc_proc_cancel);
 315 }
 316
 317 static __be32
 318 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 319                                                void            *resp)
 320 {
 321         dprintk("lockd: UNLOCK_MSG    called\n");
 322         return nlmsvc_callback(rqstp, NLMPROC_UNLOCK_RES, argp, nlmsvc_proc_unlock);
 323 }
 324
 325 static __be32
 326 nlmsvc_proc_granted_msg(struct svc_rqst *rqstp, struct nlm_args *argp,
 327                                                 void            *resp)
 328 {
 329         dprintk("lockd: GRANTED_MSG   called\n");
 330         return nlmsvc_callback(rqstp, NLMPROC_GRANTED_RES, argp, nlmsvc_proc_granted);
 331 }
 332
 333 /*
 334  * SHARE: create a DOS share or alter existing share.
 335  */
 336 static __be32
 337 nlmsvc_proc_share(struct svc_rqst *rqstp, struct nlm_args *argp,
 338                                           struct nlm_res  *resp)
 339 {
 340         struct nlm_host *host;
 341         struct nlm_file *file;
 342
 343         dprintk("lockd: SHARE         called\n");
 344
 345         resp->cookie = argp->cookie;
 346
 347         /* Don't accept new lock requests during grace period */
 348         if (locks_in_grace() && !argp->reclaim) {
 349                 resp->status = nlm_lck_denied_grace_period;
 350                 return rpc_success;
 351         }
 352
 353         /* Obtain client and file */
 354         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 355                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 356
 357         /* Now try to create the share */
 358         resp->status = cast_status(nlmsvc_share_file(host, file, argp));
 359
 360         dprintk("lockd: SHARE         status %d\n", ntohl(resp->status));
 361         nlm_release_host(host);
 362         nlm_release_file(file);
 363         return rpc_success;
 364 }
 365
 366 /*
 367  * UNSHARE: Release a DOS share.
 368  */
 369 static __be32
 370 nlmsvc_proc_unshare(struct svc_rqst *rqstp, struct nlm_args *argp,
 371                                             struct nlm_res  *resp)
 372 {
 373         struct nlm_host *host;
 374         struct nlm_file *file;
 375
 376         dprintk("lockd: UNSHARE       called\n");
 377
 378         resp->cookie = argp->cookie;
 379
 380         /* Don't accept requests during grace period */
 381         if (locks_in_grace()) {
 382                 resp->status = nlm_lck_denied_grace_period;
 383                 return rpc_success;
 384         }
 385
 386         /* Obtain client and file */
 387         if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
 388                 return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;
 389
 390         /* Now try to unshare the file */
 391         resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));
 392
 393         dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
 394         nlm_release_host(host);
 395         nlm_release_file(file);
 396         return rpc_success;
 397 }
 398
 399 /*
 400  * NM_LOCK: Create an unmonitored lock
 401  */
 402 static __be32
 403 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
 404                                             struct nlm_res  *resp)
 405 {
 406         dprintk("lockd: NM_LOCK       called\n");
 407
 408         argp->monitor = 0;              /* just clean the monitor flag */
 409         return nlmsvc_proc_lock(rqstp, argp, resp);
 410 }
 411
 412 /*
 413  * FREE_ALL: Release all locks and shares held by client
 414  */
 415 static __be32
 416 nlmsvc_proc_free_all(struct svc_rqst *rqstp, struct nlm_args *argp,
 417                                              void            *resp)
 418 {
 419         struct nlm_host *host;
 420
 421         /* Obtain client */
 422         if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
 423                 return rpc_success;
 424
 425         nlmsvc_free_host_resources(host);
 426         nlm_release_host(host);
 427         return rpc_success;
 428 }
 429
 430 /*
 431  * SM_NOTIFY: private callback from statd (not part of official NLM proto)
 432  */
 433 static __be32
 434 nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 435                                               void              *resp)
 436 {
 437         dprintk("lockd: SM_NOTIFY     called\n");
 438
 439         if (!nlm_privileged_requester(rqstp)) {
 440                 char buf[RPC_MAX_ADDRBUFLEN];
 441                 printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
 442                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 443                 return rpc_system_err;
 444         }
 445
 446         nlm_host_rebooted(argp);
 447         return rpc_success;
 448 }
 449
 450 /*
 451  * client sent a GRANTED_RES, let's remove the associated block
 452  */
 453 static __be32
 454 nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res  *argp,
 455                                                 void            *resp)
 456 {
 457         if (!nlmsvc_ops)
 458                 return rpc_success;
 459
 460         dprintk("lockd: GRANTED_RES   called\n");
 461
 462         nlmsvc_grant_reply(&argp->cookie, argp->status);
 463         return rpc_success;
 464 }
 465
 466 /*
 467  * NLM Server procedures.
 468  */
 469
 470 #define nlmsvc_encode_norep     nlmsvc_encode_void
 471 #define nlmsvc_decode_norep     nlmsvc_decode_void
 472 #define nlmsvc_decode_testres   nlmsvc_decode_void
 473 #define nlmsvc_decode_lockres   nlmsvc_decode_void
 474 #define nlmsvc_decode_unlockres nlmsvc_decode_void
 475 #define nlmsvc_decode_cancelres nlmsvc_decode_void
 476 #define nlmsvc_decode_grantedres        nlmsvc_decode_void
 477
 478 #define nlmsvc_proc_none        nlmsvc_proc_null
 479 #define nlmsvc_proc_test_res    nlmsvc_proc_null
 480 #define nlmsvc_proc_lock_res    nlmsvc_proc_null
 481 #define nlmsvc_proc_cancel_res  nlmsvc_proc_null
 482 #define nlmsvc_proc_unlock_res  nlmsvc_proc_null
 483
 484 struct nlm_void                 { int dummy; };
 485
 486 #define PROC(name, xargt, xrest, argt, rest, respsize)  \
 487  { .pc_func     = (svc_procfunc) nlmsvc_proc_##name,    \
 488    .pc_decode   = (kxdrproc_t) nlmsvc_decode_##xargt,   \
 489    .pc_encode   = (kxdrproc_t) nlmsvc_encode_##xrest,   \
 490    .pc_release  = NULL,                                 \
 491    .pc_argsize  = sizeof(struct nlm_##argt),            \
 492    .pc_ressize  = sizeof(struct nlm_##rest),            \
 493    .pc_xdrressize = respsize,                           \
 494  }
 495
 496 #define Ck      (1+XDR_QUADLEN(NLM_MAXCOOKIELEN))       /* cookie */
 497 #define St      1                               /* status */
 498 #define No      (1+1024/4)                      /* Net Obj */
 499 #define Rg      2                               /* range - offset + size */
 500
 501 struct svc_procedure            nlmsvc_procedures[] = {
 502   PROC(null,            void,           void,           void,   void, 1),
 503   PROC(test,            testargs,       testres,        args,   res, Ck+St+2+No+Rg),
 504   PROC(lock,            lockargs,       res,            args,   res, Ck+St),
 505   PROC(cancel,          cancargs,       res,            args,   res, Ck+St),
 506   PROC(unlock,          unlockargs,     res,            args,   res, Ck+St),
 507   PROC(granted,         testargs,       res,            args,   res, Ck+St),
 508   PROC(test_msg,        testargs,       norep,          args,   void, 1),
 509   PROC(lock_msg,        lockargs,       norep,          args,   void, 1),
 510   PROC(cancel_msg,      cancargs,       norep,          args,   void, 1),
 511   PROC(unlock_msg,      unlockargs,     norep,          args,   void, 1),
 512   PROC(granted_msg,     testargs,       norep,          args,   void, 1),
 513   PROC(test_res,        testres,        norep,          res,    void, 1),
 514   PROC(lock_res,        lockres,        norep,          res,    void, 1),
 515   PROC(cancel_res,      cancelres,      norep,          res,    void, 1),
 516   PROC(unlock_res,      unlockres,      norep,          res,    void, 1),
 517   PROC(granted_res,     res,            norep,          res,    void, 1),
 518   /* statd callback */
 519   PROC(sm_notify,       reboot,         void,           reboot, void, 1),
 520   PROC(none,            void,           void,           void,   void, 1),
 521   PROC(none,            void,           void,           void,   void, 1),
 522   PROC(none,            void,           void,           void,   void, 1),
 523   PROC(share,           shareargs,      shareres,       args,   res, Ck+St+1),
 524   PROC(unshare,         shareargs,      shareres,       args,   res, Ck+St+1),
 525   PROC(nm_lock,         lockargs,       res,            args,   res, Ck+St),
 526   PROC(free_all,        notify,         void,           args,   void, 0),
 527
 528 };