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                 if (!signalled ())
 316                         status = 0;
 317         }
 318         finish_wait(queue, &wait);
 319         return status;
 320 }
 321
 322 /*
 323  * Generic NLM call
 324  */
 325 int
 326 nlmclnt_call(struct nlm_rqst *req, u32 proc)
 327 {
 328         struct nlm_host *host = req->a_host;
 329         struct rpc_clnt *clnt;
 330         struct nlm_args *argp = &req->a_args;
 331         struct nlm_res  *resp = &req->a_res;
 332         struct file     *filp = argp->lock.fl.fl_file;
 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         if (filp)
 343                 msg.rpc_cred = nfs_file_cred(filp);
 344
 345         do {
 346                 if (host->h_reclaiming && !argp->reclaim)
 347                         goto in_grace_period;
 348
 349                 /* If we have no RPC client yet, create one. */
 350                 if ((clnt = nlm_bind_host(host)) == NULL)
 351                         return -ENOLCK;
 352                 msg.rpc_proc = &clnt->cl_procinfo[proc];
 353
 354                 /* Perform the RPC call. If an error occurs, try again */
 355                 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
 356                         dprintk("lockd: rpc_call returned error %d\n", -status);
 357                         switch (status) {
 358                         case -EPROTONOSUPPORT:
 359                                 status = -EINVAL;
 360                                 break;
 361                         case -ECONNREFUSED:
 362                         case -ETIMEDOUT:
 363                         case -ENOTCONN:
 364                                 nlm_rebind_host(host);
 365                                 status = -EAGAIN;
 366                                 break;
 367                         case -ERESTARTSYS:
 368                                 return signalled () ? -EINTR : status;
 369                         default:
 370                                 break;
 371                         }
 372                         break;
 373                 } else
 374                 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) {
 375                         dprintk("lockd: server in grace period\n");
 376                         if (argp->reclaim) {
 377                                 printk(KERN_WARNING
 378                                      "lockd: spurious grace period reject?!\n");
 379                                 return -ENOLCK;
 380                         }
 381                 } else {
 382                         if (!argp->reclaim) {
 383                                 /* We appear to be out of the grace period */
 384                                 wake_up_all(&host->h_gracewait);
 385                         }
 386                         dprintk("lockd: server returns status %d\n", resp->status);
 387                         return 0;       /* Okay, call complete */
 388                 }
 389
 390 in_grace_period:
 391                 /*
 392                  * The server has rebooted and appears to be in the grace
 393                  * period during which locks are only allowed to be
 394                  * reclaimed.
 395                  * We can only back off and try again later.
 396                  */
 397                 status = nlm_wait_on_grace(&host->h_gracewait);
 398         } while (status == 0);
 399
 400         return status;
 401 }
 402
 403 /*
 404  * Generic NLM call, async version.
 405  */
 406 int
 407 nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
 408 {
 409         struct nlm_host *host = req->a_host;
 410         struct rpc_clnt *clnt;
 411         struct rpc_message msg = {
 412                 .rpc_argp       = &req->a_args,
 413                 .rpc_resp       = &req->a_res,
 414         };
 415         int             status;
 416
 417         dprintk("lockd: call procedure %d on %s (async)\n",
 418                         (int)proc, host->h_name);
 419
 420         /* If we have no RPC client yet, create one. */
 421         if ((clnt = nlm_bind_host(host)) == NULL)
 422                 return -ENOLCK;
 423         msg.rpc_proc = &clnt->cl_procinfo[proc];
 424
 425         /* bootstrap and kick off the async RPC call */
 426         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
 427
 428         return status;
 429 }
 430
 431 int
 432 nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
 433 {
 434         struct nlm_host *host = req->a_host;
 435         struct rpc_clnt *clnt;
 436         struct nlm_args *argp = &req->a_args;
 437         struct nlm_res  *resp = &req->a_res;
 438         struct file     *file = argp->lock.fl.fl_file;
 439         struct rpc_message msg = {
 440                 .rpc_argp       = argp,
 441                 .rpc_resp       = resp,
 442         };
 443         int             status;
 444
 445         dprintk("lockd: call procedure %d on %s (async)\n",
 446                         (int)proc, host->h_name);
 447
 448         /* If we have no RPC client yet, create one. */
 449         if ((clnt = nlm_bind_host(host)) == NULL)
 450                 return -ENOLCK;
 451         msg.rpc_proc = &clnt->cl_procinfo[proc];
 452
 453         /* bootstrap and kick off the async RPC call */
 454         if (file)
 455                 msg.rpc_cred = nfs_file_cred(file);
 456         /* Increment host refcount */
 457         nlm_get_host(host);
 458         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
 459         if (status < 0)
 460                 nlm_release_host(host);
 461         return status;
 462 }
 463
 464 /*
 465  * TEST for the presence of a conflicting lock
 466  */
 467 static int
 468 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
 469 {
 470         int     status;
 471
 472         status = nlmclnt_call(req, NLMPROC_TEST);
 473         nlmclnt_release_lockargs(req);
 474         if (status < 0)
 475                 return status;
 476
 477         status = req->a_res.status;
 478         if (status == NLM_LCK_GRANTED) {
 479                 fl->fl_type = F_UNLCK;
 480         } if (status == NLM_LCK_DENIED) {
 481                 /*
 482                  * Report the conflicting lock back to the application.
 483                  */
 484                 locks_copy_lock(fl, &req->a_res.lock.fl);
 485                 fl->fl_pid = 0;
 486         } else {
 487                 return nlm_stat_to_errno(req->a_res.status);
 488         }
 489
 490         return 0;
 491 }
 492
 493 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
 494 {
 495         memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
 496         nlm_get_lockowner(new->fl_u.nfs_fl.owner);
 497 }
 498
 499 static void nlmclnt_locks_release_private(struct file_lock *fl)
 500 {
 501         nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
 502         fl->fl_ops = NULL;
 503 }
 504
 505 static struct file_lock_operations nlmclnt_lock_ops = {
 506         .fl_copy_lock = nlmclnt_locks_copy_lock,
 507         .fl_release_private = nlmclnt_locks_release_private,
 508 };
 509
 510 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
 511 {
 512         BUG_ON(fl->fl_ops != NULL);
 513         fl->fl_u.nfs_fl.state = 0;
 514         fl->fl_u.nfs_fl.flags = 0;
 515         fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
 516         fl->fl_ops = &nlmclnt_lock_ops;
 517 }
 518
 519 /*
 520  * LOCK: Try to create a lock
 521  *
 522  *                      Programmer Harassment Alert
 523  *
 524  * When given a blocking lock request in a sync RPC call, the HPUX lockd
 525  * will faithfully return LCK_BLOCKED but never cares to notify us when
 526  * the lock could be granted. This way, our local process could hang
 527  * around forever waiting for the callback.
 528  *
 529  *  Solution A: Implement busy-waiting
 530  *  Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
 531  *
 532  * For now I am implementing solution A, because I hate the idea of
 533  * re-implementing lockd for a third time in two months. The async
 534  * calls shouldn't be too hard to do, however.
 535  *
 536  * This is one of the lovely things about standards in the NFS area:
 537  * they're so soft and squishy you can't really blame HP for doing this.
 538  */
 539 static int
 540 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
 541 {
 542         struct nlm_host *host = req->a_host;
 543         struct nlm_res  *resp = &req->a_res;
 544         int             status;
 545
 546         if (!host->h_monitored && nsm_monitor(host) < 0) {
 547                 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
 548                                         host->h_name);
 549                 status = -ENOLCK;
 550                 goto out;
 551         }
 552
 553         do {
 554                 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
 555                         if (resp->status != NLM_LCK_BLOCKED)
 556                                 break;
 557                         status = nlmclnt_block(host, fl, &resp->status);
 558                 }
 559                 if (status < 0)
 560                         goto out;
 561         } while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
 562
 563         if (resp->status == NLM_LCK_GRANTED) {
 564                 fl->fl_u.nfs_fl.state = host->h_state;
 565                 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
 566                 fl->fl_flags |= FL_SLEEP;
 567                 if (posix_lock_file_wait(fl->fl_file, fl) < 0)
 568                                 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
 569                                                 __FUNCTION__);
 570         }
 571         status = nlm_stat_to_errno(resp->status);
 572 out:
 573         nlmclnt_release_lockargs(req);
 574         return status;
 575 }
 576
 577 /*
 578  * RECLAIM: Try to reclaim a lock
 579  */
 580 int
 581 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
 582 {
 583         struct nlm_rqst reqst, *req;
 584         int             status;
 585
 586         req = &reqst;
 587         memset(req, 0, sizeof(*req));
 588         locks_init_lock(&req->a_args.lock.fl);
 589         locks_init_lock(&req->a_res.lock.fl);
 590         req->a_host  = host;
 591         req->a_flags = 0;
 592
 593         /* Set up the argument struct */
 594         nlmclnt_setlockargs(req, fl);
 595         req->a_args.reclaim = 1;
 596
 597         if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
 598          && req->a_res.status == NLM_LCK_GRANTED)
 599                 return 0;
 600
 601         printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
 602                                 "(errno %d, status %d)\n", fl->fl_pid,
 603                                 status, req->a_res.status);
 604
 605         /*
 606          * FIXME: This is a serious failure. We can
 607          *
 608          *  a.  Ignore the problem
 609          *  b.  Send the owning process some signal (Linux doesn't have
 610          *      SIGLOST, though...)
 611          *  c.  Retry the operation
 612          *
 613          * Until someone comes up with a simple implementation
 614          * for b or c, I'll choose option a.
 615          */
 616
 617         return -ENOLCK;
 618 }
 619
 620 /*
 621  * UNLOCK: remove an existing lock
 622  */
 623 static int
 624 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
 625 {
 626         struct nlm_res  *resp = &req->a_res;
 627         int             status;
 628
 629         /* Clean the GRANTED flag now so the lock doesn't get
 630          * reclaimed while we're stuck in the unlock call. */
 631         fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
 632
 633         if (req->a_flags & RPC_TASK_ASYNC) {
 634                 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
 635                                         nlmclnt_unlock_callback);
 636                 /* Hrmf... Do the unlock early since locks_remove_posix()
 637                  * really expects us to free the lock synchronously */
 638                 posix_lock_file(fl->fl_file, fl);
 639                 if (status < 0) {
 640                         nlmclnt_release_lockargs(req);
 641                         kfree(req);
 642                 }
 643                 return status;
 644         }
 645
 646         status = nlmclnt_call(req, NLMPROC_UNLOCK);
 647         nlmclnt_release_lockargs(req);
 648         if (status < 0)
 649                 return status;
 650
 651         posix_lock_file(fl->fl_file, fl);
 652         if (resp->status == NLM_LCK_GRANTED)
 653                 return 0;
 654
 655         if (resp->status != NLM_LCK_DENIED_NOLOCKS)
 656                 printk("lockd: unexpected unlock status: %d\n", resp->status);
 657
 658         /* What to do now? I'm out of my depth... */
 659
 660         return -ENOLCK;
 661 }
 662
 663 static void
 664 nlmclnt_unlock_callback(struct rpc_task *task)
 665 {
 666         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
 667         int             status = req->a_res.status;
 668
 669         if (RPC_ASSASSINATED(task))
 670                 goto die;
 671
 672         if (task->tk_status < 0) {
 673                 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
 674                 goto retry_rebind;
 675         }
 676         if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
 677                 rpc_delay(task, NLMCLNT_GRACE_WAIT);
 678                 goto retry_unlock;
 679         }
 680         if (status != NLM_LCK_GRANTED)
 681                 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
 682 die:
 683         nlm_release_host(req->a_host);
 684         nlmclnt_release_lockargs(req);
 685         kfree(req);
 686         return;
 687  retry_rebind:
 688         nlm_rebind_host(req->a_host);
 689  retry_unlock:
 690         rpc_restart_call(task);
 691 }
 692
 693 /*
 694  * Cancel a blocked lock request.
 695  * We always use an async RPC call for this in order not to hang a
 696  * process that has been Ctrl-C'ed.
 697  */
 698 int
 699 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
 700 {
 701         struct nlm_rqst *req;
 702         unsigned long   flags;
 703         sigset_t        oldset;
 704         int             status;
 705
 706         /* Block all signals while setting up call */
 707         spin_lock_irqsave(&current->sighand->siglock, flags);
 708         oldset = current->blocked;
 709         sigfillset(&current->blocked);
 710         recalc_sigpending();
 711         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 712
 713         req = nlmclnt_alloc_call();
 714         if (!req)
 715                 return -ENOMEM;
 716         req->a_host  = host;
 717         req->a_flags = RPC_TASK_ASYNC;
 718
 719         nlmclnt_setlockargs(req, fl);
 720
 721         status = nlmclnt_async_call(req, NLMPROC_CANCEL,
 722                                         nlmclnt_cancel_callback);
 723         if (status < 0) {
 724                 nlmclnt_release_lockargs(req);
 725                 kfree(req);
 726         }
 727
 728         spin_lock_irqsave(&current->sighand->siglock, flags);
 729         current->blocked = oldset;
 730         recalc_sigpending();
 731         spin_unlock_irqrestore(&current->sighand->siglock, flags);
 732
 733         return status;
 734 }
 735
 736 static void
 737 nlmclnt_cancel_callback(struct rpc_task *task)
 738 {
 739         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
 740
 741         if (RPC_ASSASSINATED(task))
 742                 goto die;
 743
 744         if (task->tk_status < 0) {
 745                 dprintk("lockd: CANCEL call error %d, retrying.\n",
 746                                         task->tk_status);
 747                 goto retry_cancel;
 748         }
 749
 750         dprintk("lockd: cancel status %d (task %d)\n",
 751                         req->a_res.status, task->tk_pid);
 752
 753         switch (req->a_res.status) {
 754         case NLM_LCK_GRANTED:
 755         case NLM_LCK_DENIED_GRACE_PERIOD:
 756                 /* Everything's good */
 757                 break;
 758         case NLM_LCK_DENIED_NOLOCKS:
 759                 dprintk("lockd: CANCEL failed (server has no locks)\n");
 760                 goto retry_cancel;
 761         default:
 762                 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
 763                         req->a_res.status);
 764         }
 765
 766 die:
 767         nlm_release_host(req->a_host);
 768         nlmclnt_release_lockargs(req);
 769         kfree(req);
 770         return;
 771
 772 retry_cancel:
 773         nlm_rebind_host(req->a_host);
 774         rpc_restart_call(task);
 775         rpc_delay(task, 30 * HZ);
 776 }
 777
 778 /*
 779  * Convert an NLM status code to a generic kernel errno
 780  */
 781 static int
 782 nlm_stat_to_errno(u32 status)
 783 {
 784         switch(status) {
 785         case NLM_LCK_GRANTED:
 786                 return 0;
 787         case NLM_LCK_DENIED:
 788                 return -EAGAIN;
 789         case NLM_LCK_DENIED_NOLOCKS:
 790         case NLM_LCK_DENIED_GRACE_PERIOD:
 791                 return -ENOLCK;
 792         case NLM_LCK_BLOCKED:
 793                 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
 794                 return -ENOLCK;
 795 #ifdef CONFIG_LOCKD_V4
 796         case NLM_DEADLCK:
 797                 return -EDEADLK;
 798         case NLM_ROFS:
 799                 return -EROFS;
 800         case NLM_STALE_FH:
 801                 return -ESTALE;
 802         case NLM_FBIG:
 803                 return -EOVERFLOW;
 804         case NLM_FAILED:
 805                 return -ENOLCK;
 806 #endif
 807         }
 808         printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
 809         return -ENOLCK;
 810 }