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