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(¤t->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(¤t->blocked); /* Mask all signals */
238 recalc_sigpending();
239 spin_unlock_irqrestore(¤t->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(¤t->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(¤t->sighand->siglock, flags);
273 current->blocked = oldset;
274 recalc_sigpending();
275 spin_unlock_irqrestore(¤t->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(¤t->sighand->siglock, flags);
708 oldset = current->blocked;
709 sigfillset(¤t->blocked);
710 recalc_sigpending();
711 spin_unlock_irqrestore(¤t->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(¤t->sighand->siglock, flags);
729 current->blocked = oldset;
730 recalc_sigpending();
731 spin_unlock_irqrestore(¤t->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 }
811
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