Merge master.kernel.org:/pub/scm/linux/kernel/git/dwmw2/audit-2.6
[linux-2.6] / 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 #define NLMCLNT_POLL_TIMEOUT    (30*HZ)
25
26 static int      nlmclnt_test(struct nlm_rqst *, struct file_lock *);
27 static int      nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
28 static int      nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
29 static void     nlmclnt_unlock_callback(struct rpc_task *);
30 static void     nlmclnt_cancel_callback(struct rpc_task *);
31 static int      nlm_stat_to_errno(u32 stat);
32 static void     nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
33
34 /*
35  * Cookie counter for NLM requests
36  */
37 static u32      nlm_cookie = 0x1234;
38
39 static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
40 {
41         memcpy(c->data, &nlm_cookie, 4);
42         memset(c->data+4, 0, 4);
43         c->len=4;
44         nlm_cookie++;
45 }
46
47 static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
48 {
49         atomic_inc(&lockowner->count);
50         return lockowner;
51 }
52
53 static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
54 {
55         if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
56                 return;
57         list_del(&lockowner->list);
58         spin_unlock(&lockowner->host->h_lock);
59         nlm_release_host(lockowner->host);
60         kfree(lockowner);
61 }
62
63 static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
64 {
65         struct nlm_lockowner *lockowner;
66         list_for_each_entry(lockowner, &host->h_lockowners, list) {
67                 if (lockowner->pid == pid)
68                         return -EBUSY;
69         }
70         return 0;
71 }
72
73 static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
74 {
75         uint32_t res;
76         do {
77                 res = host->h_pidcount++;
78         } while (nlm_pidbusy(host, res) < 0);
79         return res;
80 }
81
82 static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
83 {
84         struct nlm_lockowner *lockowner;
85         list_for_each_entry(lockowner, &host->h_lockowners, list) {
86                 if (lockowner->owner != owner)
87                         continue;
88                 return nlm_get_lockowner(lockowner);
89         }
90         return NULL;
91 }
92
93 static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
94 {
95         struct nlm_lockowner *res, *new = NULL;
96
97         spin_lock(&host->h_lock);
98         res = __nlm_find_lockowner(host, owner);
99         if (res == NULL) {
100                 spin_unlock(&host->h_lock);
101                 new = (struct nlm_lockowner *)kmalloc(sizeof(*new), GFP_KERNEL);
102                 spin_lock(&host->h_lock);
103                 res = __nlm_find_lockowner(host, owner);
104                 if (res == NULL && new != NULL) {
105                         res = new;
106                         atomic_set(&new->count, 1);
107                         new->owner = owner;
108                         new->pid = __nlm_alloc_pid(host);
109                         new->host = nlm_get_host(host);
110                         list_add(&new->list, &host->h_lockowners);
111                         new = NULL;
112                 }
113         }
114         spin_unlock(&host->h_lock);
115         if (new != NULL)
116                 kfree(new);
117         return res;
118 }
119
120 /*
121  * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
122  */
123 static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
124 {
125         struct nlm_args *argp = &req->a_args;
126         struct nlm_lock *lock = &argp->lock;
127
128         nlmclnt_next_cookie(&argp->cookie);
129         argp->state   = nsm_local_state;
130         memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
131         lock->caller  = system_utsname.nodename;
132         lock->oh.data = req->a_owner;
133         lock->oh.len  = sprintf(req->a_owner, "%d@%s",
134                                 current->pid, system_utsname.nodename);
135         locks_copy_lock(&lock->fl, fl);
136 }
137
138 static void nlmclnt_release_lockargs(struct nlm_rqst *req)
139 {
140         struct file_lock *fl = &req->a_args.lock.fl;
141
142         if (fl->fl_ops && fl->fl_ops->fl_release_private)
143                 fl->fl_ops->fl_release_private(fl);
144 }
145
146 /*
147  * Initialize arguments for GRANTED call. The nlm_rqst structure
148  * has been cleared already.
149  */
150 int
151 nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
152 {
153         locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
154         memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
155         call->a_args.lock.caller = system_utsname.nodename;
156         call->a_args.lock.oh.len = lock->oh.len;
157
158         /* set default data area */
159         call->a_args.lock.oh.data = call->a_owner;
160
161         if (lock->oh.len > NLMCLNT_OHSIZE) {
162                 void *data = kmalloc(lock->oh.len, GFP_KERNEL);
163                 if (!data) {
164                         nlmclnt_freegrantargs(call);
165                         return 0;
166                 }
167                 call->a_args.lock.oh.data = (u8 *) data;
168         }
169
170         memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
171         return 1;
172 }
173
174 void
175 nlmclnt_freegrantargs(struct nlm_rqst *call)
176 {
177         struct file_lock *fl = &call->a_args.lock.fl;
178         /*
179          * Check whether we allocated memory for the owner.
180          */
181         if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
182                 kfree(call->a_args.lock.oh.data);
183         }
184         if (fl->fl_ops && fl->fl_ops->fl_release_private)
185                 fl->fl_ops->fl_release_private(fl);
186 }
187
188 /*
189  * This is the main entry point for the NLM client.
190  */
191 int
192 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
193 {
194         struct nfs_server       *nfssrv = NFS_SERVER(inode);
195         struct nlm_host         *host;
196         struct nlm_rqst         reqst, *call = &reqst;
197         sigset_t                oldset;
198         unsigned long           flags;
199         int                     status, proto, vers;
200
201         vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
202         if (NFS_PROTO(inode)->version > 3) {
203                 printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
204                 return -ENOLCK;
205         }
206
207         /* Retrieve transport protocol from NFS client */
208         proto = NFS_CLIENT(inode)->cl_xprt->prot;
209
210         if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
211                 return -ENOLCK;
212
213         /* Create RPC client handle if not there, and copy soft
214          * and intr flags from NFS client. */
215         if (host->h_rpcclnt == NULL) {
216                 struct rpc_clnt *clnt;
217
218                 /* Bind an rpc client to this host handle (does not
219                  * perform a portmapper lookup) */
220                 if (!(clnt = nlm_bind_host(host))) {
221                         status = -ENOLCK;
222                         goto done;
223                 }
224                 clnt->cl_softrtry = nfssrv->client->cl_softrtry;
225                 clnt->cl_intr     = nfssrv->client->cl_intr;
226                 clnt->cl_chatty   = nfssrv->client->cl_chatty;
227         }
228
229         /* Keep the old signal mask */
230         spin_lock_irqsave(&current->sighand->siglock, flags);
231         oldset = current->blocked;
232
233         /* If we're cleaning up locks because the process is exiting,
234          * perform the RPC call asynchronously. */
235         if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
236             && fl->fl_type == F_UNLCK
237             && (current->flags & PF_EXITING)) {
238                 sigfillset(&current->blocked);  /* Mask all signals */
239                 recalc_sigpending();
240                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
241
242                 call = nlmclnt_alloc_call();
243                 if (!call) {
244                         status = -ENOMEM;
245                         goto out_restore;
246                 }
247                 call->a_flags = RPC_TASK_ASYNC;
248         } else {
249                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
250                 memset(call, 0, sizeof(*call));
251                 locks_init_lock(&call->a_args.lock.fl);
252                 locks_init_lock(&call->a_res.lock.fl);
253         }
254         call->a_host = host;
255
256         nlmclnt_locks_init_private(fl, host);
257
258         /* Set up the argument struct */
259         nlmclnt_setlockargs(call, fl);
260
261         if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
262                 if (fl->fl_type != F_UNLCK) {
263                         call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
264                         status = nlmclnt_lock(call, fl);
265                 } else
266                         status = nlmclnt_unlock(call, fl);
267         } else if (IS_GETLK(cmd))
268                 status = nlmclnt_test(call, fl);
269         else
270                 status = -EINVAL;
271
272  out_restore:
273         spin_lock_irqsave(&current->sighand->siglock, flags);
274         current->blocked = oldset;
275         recalc_sigpending();
276         spin_unlock_irqrestore(&current->sighand->siglock, flags);
277
278 done:
279         dprintk("lockd: clnt proc returns %d\n", status);
280         nlm_release_host(host);
281         return status;
282 }
283 EXPORT_SYMBOL(nlmclnt_proc);
284
285 /*
286  * Allocate an NLM RPC call struct
287  */
288 struct nlm_rqst *
289 nlmclnt_alloc_call(void)
290 {
291         struct nlm_rqst *call;
292
293         while (!signalled()) {
294                 call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
295                 if (call) {
296                         memset(call, 0, sizeof(*call));
297                         locks_init_lock(&call->a_args.lock.fl);
298                         locks_init_lock(&call->a_res.lock.fl);
299                         return call;
300                 }
301                 printk("nlmclnt_alloc_call: failed, waiting for memory\n");
302                 schedule_timeout_interruptible(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();
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         long timeout;
557         int status;
558
559         if (!host->h_monitored && nsm_monitor(host) < 0) {
560                 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
561                                         host->h_name);
562                 status = -ENOLCK;
563                 goto out;
564         }
565
566         if (req->a_args.block) {
567                 status = nlmclnt_prepare_block(req, host, fl);
568                 if (status < 0)
569                         goto out;
570         }
571         for(;;) {
572                 status = nlmclnt_call(req, NLMPROC_LOCK);
573                 if (status < 0)
574                         goto out_unblock;
575                 if (resp->status != NLM_LCK_BLOCKED)
576                         break;
577                 /* Wait on an NLM blocking lock */
578                 timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT);
579                 /* Did a reclaimer thread notify us of a server reboot? */
580                 if (resp->status ==  NLM_LCK_DENIED_GRACE_PERIOD)
581                         continue;
582                 if (resp->status != NLM_LCK_BLOCKED)
583                         break;
584                 if (timeout >= 0)
585                         continue;
586                 /* We were interrupted. Send a CANCEL request to the server
587                  * and exit
588                  */
589                 status = (int)timeout;
590                 goto out_unblock;
591         }
592
593         if (resp->status == NLM_LCK_GRANTED) {
594                 fl->fl_u.nfs_fl.state = host->h_state;
595                 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
596                 fl->fl_flags |= FL_SLEEP;
597                 do_vfs_lock(fl);
598         }
599         status = nlm_stat_to_errno(resp->status);
600 out_unblock:
601         nlmclnt_finish_block(req);
602         /* Cancel the blocked request if it is still pending */
603         if (resp->status == NLM_LCK_BLOCKED)
604                 nlmclnt_cancel(host, fl);
605 out:
606         nlmclnt_release_lockargs(req);
607         return status;
608 }
609
610 /*
611  * RECLAIM: Try to reclaim a lock
612  */
613 int
614 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
615 {
616         struct nlm_rqst reqst, *req;
617         int             status;
618
619         req = &reqst;
620         memset(req, 0, sizeof(*req));
621         locks_init_lock(&req->a_args.lock.fl);
622         locks_init_lock(&req->a_res.lock.fl);
623         req->a_host  = host;
624         req->a_flags = 0;
625
626         /* Set up the argument struct */
627         nlmclnt_setlockargs(req, fl);
628         req->a_args.reclaim = 1;
629
630         if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
631          && req->a_res.status == NLM_LCK_GRANTED)
632                 return 0;
633
634         printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
635                                 "(errno %d, status %d)\n", fl->fl_pid,
636                                 status, req->a_res.status);
637
638         /*
639          * FIXME: This is a serious failure. We can
640          *
641          *  a.  Ignore the problem
642          *  b.  Send the owning process some signal (Linux doesn't have
643          *      SIGLOST, though...)
644          *  c.  Retry the operation
645          *
646          * Until someone comes up with a simple implementation
647          * for b or c, I'll choose option a.
648          */
649
650         return -ENOLCK;
651 }
652
653 /*
654  * UNLOCK: remove an existing lock
655  */
656 static int
657 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
658 {
659         struct nlm_res  *resp = &req->a_res;
660         int             status;
661
662         /* Clean the GRANTED flag now so the lock doesn't get
663          * reclaimed while we're stuck in the unlock call. */
664         fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
665
666         if (req->a_flags & RPC_TASK_ASYNC) {
667                 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
668                                         nlmclnt_unlock_callback);
669                 /* Hrmf... Do the unlock early since locks_remove_posix()
670                  * really expects us to free the lock synchronously */
671                 do_vfs_lock(fl);
672                 if (status < 0) {
673                         nlmclnt_release_lockargs(req);
674                         kfree(req);
675                 }
676                 return status;
677         }
678
679         status = nlmclnt_call(req, NLMPROC_UNLOCK);
680         nlmclnt_release_lockargs(req);
681         if (status < 0)
682                 return status;
683
684         do_vfs_lock(fl);
685         if (resp->status == NLM_LCK_GRANTED)
686                 return 0;
687
688         if (resp->status != NLM_LCK_DENIED_NOLOCKS)
689                 printk("lockd: unexpected unlock status: %d\n", resp->status);
690
691         /* What to do now? I'm out of my depth... */
692
693         return -ENOLCK;
694 }
695
696 static void
697 nlmclnt_unlock_callback(struct rpc_task *task)
698 {
699         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
700         int             status = req->a_res.status;
701
702         if (RPC_ASSASSINATED(task))
703                 goto die;
704
705         if (task->tk_status < 0) {
706                 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
707                 goto retry_rebind;
708         }
709         if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
710                 rpc_delay(task, NLMCLNT_GRACE_WAIT);
711                 goto retry_unlock;
712         }
713         if (status != NLM_LCK_GRANTED)
714                 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
715 die:
716         nlm_release_host(req->a_host);
717         nlmclnt_release_lockargs(req);
718         kfree(req);
719         return;
720  retry_rebind:
721         nlm_rebind_host(req->a_host);
722  retry_unlock:
723         rpc_restart_call(task);
724 }
725
726 /*
727  * Cancel a blocked lock request.
728  * We always use an async RPC call for this in order not to hang a
729  * process that has been Ctrl-C'ed.
730  */
731 int
732 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
733 {
734         struct nlm_rqst *req;
735         unsigned long   flags;
736         sigset_t        oldset;
737         int             status;
738
739         /* Block all signals while setting up call */
740         spin_lock_irqsave(&current->sighand->siglock, flags);
741         oldset = current->blocked;
742         sigfillset(&current->blocked);
743         recalc_sigpending();
744         spin_unlock_irqrestore(&current->sighand->siglock, flags);
745
746         req = nlmclnt_alloc_call();
747         if (!req)
748                 return -ENOMEM;
749         req->a_host  = host;
750         req->a_flags = RPC_TASK_ASYNC;
751
752         nlmclnt_setlockargs(req, fl);
753
754         status = nlmclnt_async_call(req, NLMPROC_CANCEL,
755                                         nlmclnt_cancel_callback);
756         if (status < 0) {
757                 nlmclnt_release_lockargs(req);
758                 kfree(req);
759         }
760
761         spin_lock_irqsave(&current->sighand->siglock, flags);
762         current->blocked = oldset;
763         recalc_sigpending();
764         spin_unlock_irqrestore(&current->sighand->siglock, flags);
765
766         return status;
767 }
768
769 static void
770 nlmclnt_cancel_callback(struct rpc_task *task)
771 {
772         struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
773
774         if (RPC_ASSASSINATED(task))
775                 goto die;
776
777         if (task->tk_status < 0) {
778                 dprintk("lockd: CANCEL call error %d, retrying.\n",
779                                         task->tk_status);
780                 goto retry_cancel;
781         }
782
783         dprintk("lockd: cancel status %d (task %d)\n",
784                         req->a_res.status, task->tk_pid);
785
786         switch (req->a_res.status) {
787         case NLM_LCK_GRANTED:
788         case NLM_LCK_DENIED_GRACE_PERIOD:
789                 /* Everything's good */
790                 break;
791         case NLM_LCK_DENIED_NOLOCKS:
792                 dprintk("lockd: CANCEL failed (server has no locks)\n");
793                 goto retry_cancel;
794         default:
795                 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
796                         req->a_res.status);
797         }
798
799 die:
800         nlm_release_host(req->a_host);
801         nlmclnt_release_lockargs(req);
802         kfree(req);
803         return;
804
805 retry_cancel:
806         nlm_rebind_host(req->a_host);
807         rpc_restart_call(task);
808         rpc_delay(task, 30 * HZ);
809 }
810
811 /*
812  * Convert an NLM status code to a generic kernel errno
813  */
814 static int
815 nlm_stat_to_errno(u32 status)
816 {
817         switch(status) {
818         case NLM_LCK_GRANTED:
819                 return 0;
820         case NLM_LCK_DENIED:
821                 return -EAGAIN;
822         case NLM_LCK_DENIED_NOLOCKS:
823         case NLM_LCK_DENIED_GRACE_PERIOD:
824                 return -ENOLCK;
825         case NLM_LCK_BLOCKED:
826                 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
827                 return -ENOLCK;
828 #ifdef CONFIG_LOCKD_V4
829         case NLM_DEADLCK:
830                 return -EDEADLK;
831         case NLM_ROFS:
832                 return -EROFS;
833         case NLM_STALE_FH:
834                 return -ESTALE;
835         case NLM_FBIG:
836                 return -EOVERFLOW;
837         case NLM_FAILED:
838                 return -ENOLCK;
839 #endif
840         }
841         printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
842         return -ENOLCK;
843 }