fs/lockd/clntproc.c

   1 /*
   2  * linux/fs/lockd/clntproc.c
   3  *
   4  * RPC procedures for the client side NLM implementation
   5  *
   6  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #include <linux/config.h>
  10 #include <linux/module.h>
  11 #include <linux/types.h>
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/nfs_fs.h>
  15 #include <linux/utsname.h>
  16 #include <linux/smp_lock.h>
  17 #include <linux/sunrpc/clnt.h>
  18 #include <linux/sunrpc/svc.h>
  19 #include <linux/lockd/lockd.h>
  20 #include <linux/lockd/sm_inter.h>
  21
  22 #define NLMDBG_FACILITY         NLMDBG_CLIENT
  23 #define NLMCLNT_GRACE_WAIT      (5*HZ)
  24
  25 static int      nlmclnt_test(struct nlm_rqst *, struct file_lock *);
  26 static int      nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
  27 static int      nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
  28 static void     nlmclnt_unlock_callback(struct rpc_task *);
  29 static void     nlmclnt_cancel_callback(struct rpc_task *);
  30 static int      nlm_stat_to_errno(u32 stat);
  31 static void     nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
  32
  33 /*
  34  * Cookie counter for NLM requests
  35  */
  36 static u32      nlm_cookie = 0x1234;
  37
  38 static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
  39 {
  40         memcpy(c->data, &nlm_cookie, 4);
  41         memset(c->data+4, 0, 4);
  42         c->len=4;
  43         nlm_cookie++;
  44 }
  45
  46 static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
  47 {
  48         atomic_inc(&lockowner->count);
  49         return lockowner;
  50 }
  51
  52 static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
  53 {
  54         if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
  55                 return;
  56         list_del(&lockowner->list);
  57         spin_unlock(&lockowner->host->h_lock);
  58         nlm_release_host(lockowner->host);
  59         kfree(lockowner);
  60 }
  61
  62 static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
  63 {
  64         struct nlm_lockowner *lockowner;
  65         list_for_each_entry(lockowner, &host->h_lockowners, list) {
  66                 if (lockowner->pid == pid)
  67                         return -EBUSY;
  68         }
  69         return 0;
  70 }
  71
  72 static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
  73 {
  74         uint32_t res;
  75         do {
  76                 res = host->h_pidcount++;
  77         } while (nlm_pidbusy(host, res) < 0);
  78         return res;
  79 }
  80
  81 static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
  82 {
  83         struct nlm_lockowner *lockowner;
  84         list_for_each_entry(lockowner, &host->h_lockowners, list) {
  85                 if (lockowner->owner != owner)
  86                         continue;
  87                 return nlm_get_lockowner(lockowner);
  88         }
  89         return NULL;
  90 }
  91
  92 static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
  93 {
  94         struct nlm_lockowner *res, *new = NULL;
  95
  96         spin_lock(&host->h_lock);
  97         res = __nlm_find_lockowner(host, owner);
  98         if (res == NULL) {
  99                 spin_unlock(&host->h_lock);
 100                 new = (struct nlm_lockowner *)kmalloc(sizeof(*new), GFP_KERNEL);
 101                 spin_lock(&host->h_lock);
 102                 res = __nlm_find_lockowner(host, owner);
 103                 if (res == NULL && new != NULL) {
 104                         res = new;
 105                         atomic_set(&new->count, 1);
 106                         new->owner = owner;
 107                         new->pid = __nlm_alloc_pid(host);
 108                         new->host = nlm_get_host(host);
 109                         list_add(&new->list, &host->h_lockowners);
 110                         new = NULL;
 111                 }
 112         }
 113         spin_unlock(&host->h_lock);
 114         if (new != NULL)
 115                 kfree(new);
 116         return res;
 117 }
 118
 119 /*
 120  * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
 121  */
 122 static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
 123 {
 124         struct nlm_args *argp = &req->a_args;
 125         struct nlm_lock *lock = &argp->lock;
 126
 127         nlmclnt_next_cookie(&argp->cookie);
 128         argp->state   = nsm_local_state;
 129         memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
 130         lock->caller  = system_utsname.nodename;
 131         lock->oh.data = req->a_owner;
 132         lock->oh.len  = sprintf(req->a_owner, "%d@%s",
 133                                 current->pid, system_utsname.nodename);
 134         locks_copy_lock(&lock->fl, fl);
 135 }
 136
 137 static void nlmclnt_release_lockargs(struct nlm_rqst *req)
 138 {
 139         struct file_lock *fl = &req->a_args.lock.fl;
 140
 141         if (fl->fl_ops && fl->fl_ops->fl_release_private)
 142                 fl->fl_ops->fl_release_private(fl);
 143 }
 144
 145 /*
 146  * Initialize arguments for GRANTED call. The nlm_rqst structure
 147  * has been cleared already.
 148  */
 149 int
 150 nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
 151 {
 152         locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
 153         memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
 154         call->a_args.lock.caller = system_utsname.nodename;
 155         call->a_args.lock.oh.len = lock->oh.len;
 156
 157         /* set default data area */
 158         call->a_args.lock.oh.data = call->a_owner;
 159
 160         if (lock->oh.len > NLMCLNT_OHSIZE) {
 161                 void *data = kmalloc(lock->oh.len, GFP_KERNEL);
 162                 if (!data) {
 163                         nlmclnt_freegrantargs(call);
 164                         return 0;
 165                 }
 166                 call->a_args.lock.oh.data = (u8 *) data;
 167         }
 168
 169         memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
 170         return 1;
 171 }
 172
 173 void
 174 nlmclnt_freegrantargs(struct nlm_rqst *call)
 175 {
 176         struct file_lock *fl = &call->a_args.lock.fl;
 177         /*
 178          * Check whether we allocated memory for the owner.
 179          */
 180         if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
 181                 kfree(call->a_args.lock.oh.data);
 182         }
 183         if (fl->fl_ops && fl->fl_ops->fl_release_private)
 184                 fl->fl_ops->fl_release_private(fl);
 185 }
 186
 187 /*
 188  * This is the main entry point for the NLM client.
 189  */
 190 int
 191 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 192 {
 193         struct nfs_server       *nfssrv = NFS_SERVER(inode);
 194         struct nlm_host         *host;
 195         struct nlm_rqst         reqst, *call = &reqst;
 196         sigset_t                oldset;
 197         unsigned long           flags;
 198         int                     status, proto, vers;
 199
 200         vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
 201         if (NFS_PROTO(inode)->version > 3) {
 202                 printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
 203                 return -ENOLCK;
 204         }
 205
 206         /* Retrieve transport protocol from NFS client */
 207         proto = NFS_CLIENT(inode)->cl_xprt->prot;
 208
 209         if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
 210                 return -ENOLCK;
 211
 212         /* Create RPC client handle if not there, and copy soft
 213          * and intr flags from NFS client. */
 214         if (host->h_rpcclnt == NULL) {
 215                 struct rpc_clnt *clnt;
 216
 217                 /* Bind an rpc client to this host handle (does not
 218                  * perform a portmapper lookup) */
 219                 if (!(clnt = nlm_bind_host(host))) {
 220                         status = -ENOLCK;
 221                         goto done;
 222                 }
 223                 clnt->cl_softrtry = nfssrv->client->cl_softrtry;
 224                 clnt->cl_intr     = nfssrv->client->cl_intr;
 225                 clnt->cl_chatty   = nfssrv->client->cl_chatty;
 226         }
 227
 228         /* Keep the old signal mask */
 229         spin_lock_irqsave(&current->sighand->siglock, flags);
 230         oldset = current->blocked;
 231
 232         /* If we're cleaning up locks because the process is exiting,
 233          * perform the RPC call asynchronously. */
 234         if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
 235             && fl->fl_type == F_UNLCK
 236             && (current->flags & PF_EXITING)) {
 237                 sigfillset(&current->blocked);  /* Mask all signals */
 238                 recalc_sigpending();
 239                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 240
 241                 call = nlmclnt_alloc_call();
 242                 if (!call) {
 243                         status = -ENOMEM;
 244                         goto out_restore;
 245                 }
 246                 call->a_flags = RPC_TASK_ASYNC;
 247         } else {
 248                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 249                 memset(call, 0, sizeof(*call));
 250                 locks_init_lock(&call->a_args.lock.fl);
 251                 locks_init_lock(&call->a_res.lock.fl);
 252         }
 253         call->a_host = host;
 254
 255         nlmclnt_locks_init_private(fl, host);
 256
 257         /* Set up the argument struct */
 258         nlmclnt_setlockargs(call, fl);
 259
 260         if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
 261                 if (fl->fl_type != F_UNLCK) {
 262                         call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
 263                         status = nlmclnt_lock(call, fl);
 264                 } else
 265                         status = nlmclnt_unlock(call, fl);
 266         } else if (IS_GETLK(cmd))
 267                 status = nlmclnt_test(call, fl);
 268         else
 269                 status = -EINVAL;
 270
 271  out_restore:
 272         spin_lock_irqsave(&current->sighand->siglock, flags);
 273         current->blocked = oldset;
 274         recalc_sigpending();
 275         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 276
 277 done:
 278         dprintk("lockd: clnt proc returns %d\n", status);
 279         nlm_release_host(host);
 280         return status;
 281 }
 282 EXPORT_SYMBOL(nlmclnt_proc);
 283
 284 /*
 285  * Allocate an NLM RPC call struct
 286  */
 287 struct nlm_rqst *
 288 nlmclnt_alloc_call(void)
 289 {
 290         struct nlm_rqst *call;
 291
 292         while (!signalled()) {
 293                 call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
 294                 if (call) {
 295                         memset(call, 0, sizeof(*call));
 296                         locks_init_lock(&call->a_args.lock.fl);
 297                         locks_init_lock(&call->a_res.lock.fl);
 298                         return call;
 299                 }
 300                 printk("nlmclnt_alloc_call: failed, waiting for memory\n");
 301                 current->state = TASK_INTERRUPTIBLE;
 302                 schedule_timeout(5*HZ);
 303         }
 304         return NULL;
 305 }
 306
 307 static int nlm_wait_on_grace(wait_queue_head_t *queue)
 308 {
 309         DEFINE_WAIT(wait);
 310         int status = -EINTR;
 311
 312         prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
 313         if (!signalled ()) {
 314                 schedule_timeout(NLMCLNT_GRACE_WAIT);
 315                 try_to_freeze(PF_FREEZE);
 316                 if (!signalled ())
 317                         status = 0;
 318         }
 319         finish_wait(queue, &wait);
 320         return status;
 321 }
 322
 323 /*
 324  * Generic NLM call
 325  */
 326 static int
 327 nlmclnt_call(struct nlm_rqst *req, u32 proc)
 328 {
 329         struct nlm_host *host = req->a_host;
 330         struct rpc_clnt *clnt;
 331         struct nlm_args *argp = &req->a_args;
 332         struct nlm_res  *resp = &req->a_res;
 333         struct rpc_message msg = {
 334                 .rpc_argp       = argp,
 335                 .rpc_resp       = resp,
 336         };
 337         int             status;
 338
 339         dprintk("lockd: call procedure %d on %s\n",
 340                         (int)proc, host->h_name);
 341
 342         do {
 343                 if (host->h_reclaiming && !argp->reclaim)
 344                         goto in_grace_period;
 345
 346                 /* If we have no RPC client yet, create one. */
 347                 if ((clnt = nlm_bind_host(host)) == NULL)
 348                         return -ENOLCK;
 349                 msg.rpc_proc = &clnt->cl_procinfo[proc];
 350
 351                 /* Perform the RPC call. If an error occurs, try again */
 352                 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
 353                         dprintk("lockd: rpc_call returned error %d\n", -status);
 354                         switch (status) {
 355                         case -EPROTONOSUPPORT:
 356                                 status = -EINVAL;
 357                                 break;
 358                         case -ECONNREFUSED:
 359                         case -ETIMEDOUT:
 360                         case -ENOTCONN:
 361                                 nlm_rebind_host(host);
 362                                 status = -EAGAIN;
 363                                 break;
 364                         case -ERESTARTSYS:
 365                                 return signalled () ? -EINTR : status;
 366                         default:
 367                                 break;
 368                         }
 369                         break;
 370                 } else
 371                 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) {
 372                         dprintk("lockd: server in grace period\n");
 373                         if (argp->reclaim) {
 374                                 printk(KERN_WARNING
 375                                      "lockd: spurious grace period reject?!\n");
 376                                 return -ENOLCK;
 377                         }
 378                 } else {
 379                         if (!argp->reclaim) {
 380                                 /* We appear to be out of the grace period */
 381                                 wake_up_all(&host->h_gracewait);
 382                         }
 383                         dprintk("lockd: server returns status %d\n", resp->status);
 384                         return 0;       /* Okay, call complete */
 385                 }
 386
 387 in_grace_period:
 388                 /*
 389                  * The server has rebooted and appears to be in the grace
 390                  * period during which locks are only allowed to be
 391                  * reclaimed.
 392                  * We can only back off and try again later.
 393                  */
 394                 status = nlm_wait_on_grace(&host->h_gracewait);
 395         } while (status == 0);
 396
 397         return status;
 398 }
 399
 400 /*
 401  * Generic NLM call, async version.
 402  */
 403 int
 404 nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
 405 {
 406         struct nlm_host *host = req->a_host;
 407         struct rpc_clnt *clnt;
 408         struct rpc_message msg = {
 409                 .rpc_argp       = &req->a_args,
 410                 .rpc_resp       = &req->a_res,
 411         };
 412         int             status;
 413
 414         dprintk("lockd: call procedure %d on %s (async)\n",
 415                         (int)proc, host->h_name);
 416
 417         /* If we have no RPC client yet, create one. */
 418         if ((clnt = nlm_bind_host(host)) == NULL)
 419                 return -ENOLCK;
 420         msg.rpc_proc = &clnt->cl_procinfo[proc];
 421
 422         /* bootstrap and kick off the async RPC call */
 423         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
 424
 425         return status;
 426 }
 427
 428 static int
 429 nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
 430 {
 431         struct nlm_host *host = req->a_host;
 432         struct rpc_clnt *clnt;
 433         struct nlm_args *argp = &req->a_args;
 434         struct nlm_res  *resp = &req->a_res;
 435         struct rpc_message msg = {
 436                 .rpc_argp       = argp,
 437                 .rpc_resp       = resp,
 438         };
 439         int             status;
 440
 441         dprintk("lockd: call procedure %d on %s (async)\n",
 442                         (int)proc, host->h_name);
 443
 444         /* If we have no RPC client yet, create one. */
 445         if ((clnt = nlm_bind_host(host)) == NULL)
 446                 return -ENOLCK;
 447         msg.rpc_proc = &clnt->cl_procinfo[proc];
 448
 449         /* Increment host refcount */
 450         nlm_get_host(host);
 451         /* bootstrap and kick off the async RPC call */
 452         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
 453         if (status < 0)
 454                 nlm_release_host(host);
 455         return status;
 456 }
 457
 458 /*
 459  * TEST for the presence of a conflicting lock
 460  */
 461 static int
 462 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
 463 {
 464         int     status;
 465
 466         status = nlmclnt_call(req, NLMPROC_TEST);
 467         nlmclnt_release_lockargs(req);
 468         if (status < 0)
 469                 return status;
 470
 471         status = req->a_res.status;
 472         if (status == NLM_LCK_GRANTED) {
 473                 fl->fl_type = F_UNLCK;
 474         } if (status == NLM_LCK_DENIED) {
 475                 /*
 476                  * Report the conflicting lock back to the application.
 477                  */
 478                 locks_copy_lock(fl, &req->a_res.lock.fl);
 479                 fl->fl_pid = 0;
 480         } else {
 481                 return nlm_stat_to_errno(req->a_res.status);
 482         }
 483
 484         return 0;
 485 }
 486
 487 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
 488 {
 489         memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
 490         nlm_get_lockowner(new->fl_u.nfs_fl.owner);
 491 }
 492
 493 static void nlmclnt_locks_release_private(struct file_lock *fl)
 494 {
 495         nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
 496         fl->fl_ops = NULL;
 497 }
 498
 499 static struct file_lock_operations nlmclnt_lock_ops = {
 500         .fl_copy_lock = nlmclnt_locks_copy_lock,
 501         .fl_release_private = nlmclnt_locks_release_private,
 502 };
 503
 504 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
 505 {
 506         BUG_ON(fl->fl_ops != NULL);
 507         fl->fl_u.nfs_fl.state = 0;
 508         fl->fl_u.nfs_fl.flags = 0;
 509         fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
 510         fl->fl_ops = &nlmclnt_lock_ops;
 511 }
 512
 513 static void do_vfs_lock(struct file_lock *fl)
 514 {
 515         int res = 0;
 516         switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
 517                 case FL_POSIX:
 518                         res = posix_lock_file_wait(fl->fl_file, fl);
 519                         break;
 520                 case FL_FLOCK:
 521                         res = flock_lock_file_wait(fl->fl_file, fl);
 522                         break;
 523                 default:
 524                         BUG();
 525         }
 526         if (res < 0)
 527                 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
 528                                 __FUNCTION__);
 529 }
 530
 531 /*
 532  * LOCK: Try to create a lock
 533  *
 534  *                      Programmer Harassment Alert
 535  *
 536  * When given a blocking lock request in a sync RPC call, the HPUX lockd
 537  * will faithfully return LCK_BLOCKED but never cares to notify us when
 538  * the lock could be granted. This way, our local process could hang
 539  * around forever waiting for the callback.
 540  *
 541  *  Solution A: Implement busy-waiting
 542  *  Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
 543  *
 544  * For now I am implementing solution A, because I hate the idea of
 545  * re-implementing lockd for a third time in two months. The async
 546  * calls shouldn't be too hard to do, however.
 547  *
 548  * This is one of the lovely things about standards in the NFS area:
 549  * they're so soft and squishy you can't really blame HP for doing this.
 550  */
 551 static int
 552 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
 553 {
 554         struct nlm_host *host = req->a_host;
 555         struct nlm_res  *resp = &req->a_res;
 556         int             status;
 557
 558         if (!host->h_monitored && nsm_monitor(host) < 0) {
 559                 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
 560                                         host->h_name);
 561                 status = -ENOLCK;
 562                 goto out;
 563         }
 564
 565         do {
 566                 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
 567                         if (resp->status != NLM_LCK_BLOCKED)
 568                                 break;
 569                         status = nlmclnt_block(host, fl, &resp->status);
 570                 }
 571                 if (status < 0)
 572                         goto out;
 573         } while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
 574
 575         if (resp->status == NLM_LCK_GRANTED) {
 576                 fl->fl_u.nfs_fl.state = host->h_state;
 577                 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
 578                 fl->fl_flags |= FL_SLEEP;
 579                 do_vfs_lock(fl);
 580         }
 581         status = nlm_stat_to_errno(resp->status);
 582 out:
 583         nlmclnt_release_lockargs(req);
 584         return status;
 585 }
 586
 587 /*
 588  * RECLAIM: Try to reclaim a lock
 589  */
 590 int
 591 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
 592 {
 593         struct nlm_rqst reqst, *req;
 594         int             status;
 595
 596         req = &reqst;
 597         memset(req, 0, sizeof(*req));
 598         locks_init_lock(&req->a_args.lock.fl);
 599         locks_init_lock(&req->a_res.lock.fl);
 600         req->a_host  = host;
 601         req->a_flags = 0;
 602
 603         /* Set up the argument struct */
 604         nlmclnt_setlockargs(req, fl);
 605         req->a_args.reclaim = 1;
 606
 607         if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
 608          && req->a_res.status == NLM_LCK_GRANTED)
 609                 return 0;
 610
 611         printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
 612                                 "(errno %d, status %d)\n", fl->fl_pid,
 613                                 status, req->a_res.status);
 614
 615         /*
 616          * FIXME: This is a serious failure. We can
 617          *
 618          *  a.  Ignore the problem
 619          *  b.  Send the owning process some signal (Linux doesn't have
 620          *      SIGLOST, though...)
 621          *  c.  Retry the operation
 622          *
 623          * Until someone comes up with a simple implementation
 624          * for b or c, I'll choose option a.
 625          */
 626
 627         return -ENOLCK;
 628 }
 629
 630 /*
 631  * UNLOCK: remove an existing lock
 632  */
 633 static int
 634 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
 635 {
 636         struct nlm_res  *resp = &req->a_res;
 637         int             status;
 638
 639         /* Clean the GRANTED flag now so the lock doesn't get
 640          * reclaimed while we're stuck in the unlock call. */
 641         fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
 642
 643         if (req->a_flags & RPC_TASK_ASYNC) {
 644                 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
 645                                         nlmclnt_unlock_callback);
 646                 /* Hrmf... Do the unlock early since locks_remove_posix()
 647                  * really expects us to free the lock synchronously */
 648                 do_vfs_lock(fl);
 649                 if (status < 0) {
 650                         nlmclnt_release_lockargs(req);
 651                         kfree(req);
 652                 }
 653                 return status;
 654         }
 655
 656         status = nlmclnt_call(req, NLMPROC_UNLOCK);
 657         nlmclnt_release_lockargs(req);
 658         if (status < 0)
 659                 return status;
 660
 661         do_vfs_lock(fl);
 662         if (resp->status == NLM_LCK_GRANTED)
 663                 return 0;
 664
 665         if (resp->status != NLM_LCK_DENIED_NOLOCKS)
 666                 printk("lockd: unexpected unlock status: %d\n", resp->status);
 667
 668         /* What to do now? I'm out of my depth... */
 669
 670         return -ENOLCK;
 671 }
 672
 673 static void
 674 nlmclnt_unlock_callback(struct rpc_task *task)
 675 {
 676         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
 677         int             status = req->a_res.status;
 678
 679         if (RPC_ASSASSINATED(task))
 680                 goto die;
 681
 682         if (task->tk_status < 0) {
 683                 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
 684                 goto retry_rebind;
 685         }
 686         if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
 687                 rpc_delay(task, NLMCLNT_GRACE_WAIT);
 688                 goto retry_unlock;
 689         }
 690         if (status != NLM_LCK_GRANTED)
 691                 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
 692 die:
 693         nlm_release_host(req->a_host);
 694         nlmclnt_release_lockargs(req);
 695         kfree(req);
 696         return;
 697  retry_rebind:
 698         nlm_rebind_host(req->a_host);
 699  retry_unlock:
 700         rpc_restart_call(task);
 701 }
 702
 703 /*
 704  * Cancel a blocked lock request.
 705  * We always use an async RPC call for this in order not to hang a
 706  * process that has been Ctrl-C'ed.
 707  */
 708 int
 709 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
 710 {
 711         struct nlm_rqst *req;
 712         unsigned long   flags;
 713         sigset_t        oldset;
 714         int             status;
 715
 716         /* Block all signals while setting up call */
 717         spin_lock_irqsave(&current->sighand->siglock, flags);
 718         oldset = current->blocked;
 719         sigfillset(&current->blocked);
 720         recalc_sigpending();
 721         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 722
 723         req = nlmclnt_alloc_call();
 724         if (!req)
 725                 return -ENOMEM;
 726         req->a_host  = host;
 727         req->a_flags = RPC_TASK_ASYNC;
 728
 729         nlmclnt_setlockargs(req, fl);
 730
 731         status = nlmclnt_async_call(req, NLMPROC_CANCEL,
 732                                         nlmclnt_cancel_callback);
 733         if (status < 0) {
 734                 nlmclnt_release_lockargs(req);
 735                 kfree(req);
 736         }
 737
 738         spin_lock_irqsave(&current->sighand->siglock, flags);
 739         current->blocked = oldset;
 740         recalc_sigpending();
 741         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 742
 743         return status;
 744 }
 745
 746 static void
 747 nlmclnt_cancel_callback(struct rpc_task *task)
 748 {
 749         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
 750
 751         if (RPC_ASSASSINATED(task))
 752                 goto die;
 753
 754         if (task->tk_status < 0) {
 755                 dprintk("lockd: CANCEL call error %d, retrying.\n",
 756                                         task->tk_status);
 757                 goto retry_cancel;
 758         }
 759
 760         dprintk("lockd: cancel status %d (task %d)\n",
 761                         req->a_res.status, task->tk_pid);
 762
 763         switch (req->a_res.status) {
 764         case NLM_LCK_GRANTED:
 765         case NLM_LCK_DENIED_GRACE_PERIOD:
 766                 /* Everything's good */
 767                 break;
 768         case NLM_LCK_DENIED_NOLOCKS:
 769                 dprintk("lockd: CANCEL failed (server has no locks)\n");
 770                 goto retry_cancel;
 771         default:
 772                 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
 773                         req->a_res.status);
 774         }
 775
 776 die:
 777         nlm_release_host(req->a_host);
 778         nlmclnt_release_lockargs(req);
 779         kfree(req);
 780         return;
 781
 782 retry_cancel:
 783         nlm_rebind_host(req->a_host);
 784         rpc_restart_call(task);
 785         rpc_delay(task, 30 * HZ);
 786 }
 787
 788 /*
 789  * Convert an NLM status code to a generic kernel errno
 790  */
 791 static int
 792 nlm_stat_to_errno(u32 status)
 793 {
 794         switch(status) {
 795         case NLM_LCK_GRANTED:
 796                 return 0;
 797         case NLM_LCK_DENIED:
 798                 return -EAGAIN;
 799         case NLM_LCK_DENIED_NOLOCKS:
 800         case NLM_LCK_DENIED_GRACE_PERIOD:
 801                 return -ENOLCK;
 802         case NLM_LCK_BLOCKED:
 803                 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
 804                 return -ENOLCK;
 805 #ifdef CONFIG_LOCKD_V4
 806         case NLM_DEADLCK:
 807                 return -EDEADLK;
 808         case NLM_ROFS:
 809                 return -EROFS;
 810         case NLM_STALE_FH:
 811                 return -ESTALE;
 812         case NLM_FBIG:
 813                 return -EOVERFLOW;
 814         case NLM_FAILED:
 815                 return -ENOLCK;
 816 #endif
 817         }
 818         printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
 819         return -ENOLCK;
 820 }