BKL: remove extraneous #include <smp_lock.h>
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / lockd / clntproc.c
blob332c54cf75e0f465f5ba91cc66999df386d4d4e0
1 /*
2 * linux/fs/lockd/clntproc.c
4 * RPC procedures for the client side NLM implementation
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
9 #include <linux/module.h>
10 #include <linux/slab.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/freezer.h>
17 #include <linux/sunrpc/clnt.h>
18 #include <linux/sunrpc/svc.h>
19 #include <linux/lockd/lockd.h>
21 #define NLMDBG_FACILITY NLMDBG_CLIENT
22 #define NLMCLNT_GRACE_WAIT (5*HZ)
23 #define NLMCLNT_POLL_TIMEOUT (30*HZ)
24 #define NLMCLNT_MAX_RETRIES 3
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 int nlm_stat_to_errno(__be32 stat);
30 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
31 static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
33 static const struct rpc_call_ops nlmclnt_unlock_ops;
34 static const struct rpc_call_ops nlmclnt_cancel_ops;
37 * Cookie counter for NLM requests
39 static atomic_t nlm_cookie = ATOMIC_INIT(0x1234);
41 void nlmclnt_next_cookie(struct nlm_cookie *c)
43 u32 cookie = atomic_inc_return(&nlm_cookie);
45 memcpy(c->data, &cookie, 4);
46 c->len=4;
49 static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
51 atomic_inc(&lockowner->count);
52 return lockowner;
55 static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
57 if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
58 return;
59 list_del(&lockowner->list);
60 spin_unlock(&lockowner->host->h_lock);
61 nlm_release_host(lockowner->host);
62 kfree(lockowner);
65 static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
67 struct nlm_lockowner *lockowner;
68 list_for_each_entry(lockowner, &host->h_lockowners, list) {
69 if (lockowner->pid == pid)
70 return -EBUSY;
72 return 0;
75 static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
77 uint32_t res;
78 do {
79 res = host->h_pidcount++;
80 } while (nlm_pidbusy(host, res) < 0);
81 return res;
84 static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
86 struct nlm_lockowner *lockowner;
87 list_for_each_entry(lockowner, &host->h_lockowners, list) {
88 if (lockowner->owner != owner)
89 continue;
90 return nlm_get_lockowner(lockowner);
92 return NULL;
95 static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
97 struct nlm_lockowner *res, *new = NULL;
99 spin_lock(&host->h_lock);
100 res = __nlm_find_lockowner(host, owner);
101 if (res == NULL) {
102 spin_unlock(&host->h_lock);
103 new = kmalloc(sizeof(*new), GFP_KERNEL);
104 spin_lock(&host->h_lock);
105 res = __nlm_find_lockowner(host, owner);
106 if (res == NULL && new != NULL) {
107 res = new;
108 atomic_set(&new->count, 1);
109 new->owner = owner;
110 new->pid = __nlm_alloc_pid(host);
111 new->host = nlm_get_host(host);
112 list_add(&new->list, &host->h_lockowners);
113 new = NULL;
116 spin_unlock(&host->h_lock);
117 kfree(new);
118 return res;
122 * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
124 static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
126 struct nlm_args *argp = &req->a_args;
127 struct nlm_lock *lock = &argp->lock;
129 nlmclnt_next_cookie(&argp->cookie);
130 memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh));
131 lock->caller = utsname()->nodename;
132 lock->oh.data = req->a_owner;
133 lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
134 (unsigned int)fl->fl_u.nfs_fl.owner->pid,
135 utsname()->nodename);
136 lock->svid = fl->fl_u.nfs_fl.owner->pid;
137 lock->fl.fl_start = fl->fl_start;
138 lock->fl.fl_end = fl->fl_end;
139 lock->fl.fl_type = fl->fl_type;
142 static void nlmclnt_release_lockargs(struct nlm_rqst *req)
144 BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
148 * nlmclnt_proc - Perform a single client-side lock request
149 * @host: address of a valid nlm_host context representing the NLM server
150 * @cmd: fcntl-style file lock operation to perform
151 * @fl: address of arguments for the lock operation
154 int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl)
156 struct nlm_rqst *call;
157 int status;
159 nlm_get_host(host);
160 call = nlm_alloc_call(host);
161 if (call == NULL)
162 return -ENOMEM;
164 nlmclnt_locks_init_private(fl, host);
165 /* Set up the argument struct */
166 nlmclnt_setlockargs(call, fl);
168 if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
169 if (fl->fl_type != F_UNLCK) {
170 call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
171 status = nlmclnt_lock(call, fl);
172 } else
173 status = nlmclnt_unlock(call, fl);
174 } else if (IS_GETLK(cmd))
175 status = nlmclnt_test(call, fl);
176 else
177 status = -EINVAL;
178 fl->fl_ops->fl_release_private(fl);
179 fl->fl_ops = NULL;
181 dprintk("lockd: clnt proc returns %d\n", status);
182 return status;
184 EXPORT_SYMBOL_GPL(nlmclnt_proc);
187 * Allocate an NLM RPC call struct
189 * Note: the caller must hold a reference to host. In case of failure,
190 * this reference will be released.
192 struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
194 struct nlm_rqst *call;
196 for(;;) {
197 call = kzalloc(sizeof(*call), GFP_KERNEL);
198 if (call != NULL) {
199 atomic_set(&call->a_count, 1);
200 locks_init_lock(&call->a_args.lock.fl);
201 locks_init_lock(&call->a_res.lock.fl);
202 call->a_host = host;
203 return call;
205 if (signalled())
206 break;
207 printk("nlm_alloc_call: failed, waiting for memory\n");
208 schedule_timeout_interruptible(5*HZ);
210 nlm_release_host(host);
211 return NULL;
214 void nlm_release_call(struct nlm_rqst *call)
216 if (!atomic_dec_and_test(&call->a_count))
217 return;
218 nlm_release_host(call->a_host);
219 nlmclnt_release_lockargs(call);
220 kfree(call);
223 static void nlmclnt_rpc_release(void *data)
225 nlm_release_call(data);
228 static int nlm_wait_on_grace(wait_queue_head_t *queue)
230 DEFINE_WAIT(wait);
231 int status = -EINTR;
233 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
234 if (!signalled ()) {
235 schedule_timeout(NLMCLNT_GRACE_WAIT);
236 try_to_freeze();
237 if (!signalled ())
238 status = 0;
240 finish_wait(queue, &wait);
241 return status;
245 * Generic NLM call
247 static int
248 nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
250 struct nlm_host *host = req->a_host;
251 struct rpc_clnt *clnt;
252 struct nlm_args *argp = &req->a_args;
253 struct nlm_res *resp = &req->a_res;
254 struct rpc_message msg = {
255 .rpc_argp = argp,
256 .rpc_resp = resp,
257 .rpc_cred = cred,
259 int status;
261 dprintk("lockd: call procedure %d on %s\n",
262 (int)proc, host->h_name);
264 do {
265 if (host->h_reclaiming && !argp->reclaim)
266 goto in_grace_period;
268 /* If we have no RPC client yet, create one. */
269 if ((clnt = nlm_bind_host(host)) == NULL)
270 return -ENOLCK;
271 msg.rpc_proc = &clnt->cl_procinfo[proc];
273 /* Perform the RPC call. If an error occurs, try again */
274 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
275 dprintk("lockd: rpc_call returned error %d\n", -status);
276 switch (status) {
277 case -EPROTONOSUPPORT:
278 status = -EINVAL;
279 break;
280 case -ECONNREFUSED:
281 case -ETIMEDOUT:
282 case -ENOTCONN:
283 nlm_rebind_host(host);
284 status = -EAGAIN;
285 break;
286 case -ERESTARTSYS:
287 return signalled () ? -EINTR : status;
288 default:
289 break;
291 break;
292 } else
293 if (resp->status == nlm_lck_denied_grace_period) {
294 dprintk("lockd: server in grace period\n");
295 if (argp->reclaim) {
296 printk(KERN_WARNING
297 "lockd: spurious grace period reject?!\n");
298 return -ENOLCK;
300 } else {
301 if (!argp->reclaim) {
302 /* We appear to be out of the grace period */
303 wake_up_all(&host->h_gracewait);
305 dprintk("lockd: server returns status %d\n", resp->status);
306 return 0; /* Okay, call complete */
309 in_grace_period:
311 * The server has rebooted and appears to be in the grace
312 * period during which locks are only allowed to be
313 * reclaimed.
314 * We can only back off and try again later.
316 status = nlm_wait_on_grace(&host->h_gracewait);
317 } while (status == 0);
319 return status;
323 * Generic NLM call, async version.
325 static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
327 struct nlm_host *host = req->a_host;
328 struct rpc_clnt *clnt;
329 struct rpc_task_setup task_setup_data = {
330 .rpc_message = msg,
331 .callback_ops = tk_ops,
332 .callback_data = req,
333 .flags = RPC_TASK_ASYNC,
336 dprintk("lockd: call procedure %d on %s (async)\n",
337 (int)proc, host->h_name);
339 /* If we have no RPC client yet, create one. */
340 clnt = nlm_bind_host(host);
341 if (clnt == NULL)
342 goto out_err;
343 msg->rpc_proc = &clnt->cl_procinfo[proc];
344 task_setup_data.rpc_client = clnt;
346 /* bootstrap and kick off the async RPC call */
347 return rpc_run_task(&task_setup_data);
348 out_err:
349 tk_ops->rpc_release(req);
350 return ERR_PTR(-ENOLCK);
353 static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
355 struct rpc_task *task;
357 task = __nlm_async_call(req, proc, msg, tk_ops);
358 if (IS_ERR(task))
359 return PTR_ERR(task);
360 rpc_put_task(task);
361 return 0;
365 * NLM asynchronous call.
367 int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
369 struct rpc_message msg = {
370 .rpc_argp = &req->a_args,
371 .rpc_resp = &req->a_res,
373 return nlm_do_async_call(req, proc, &msg, tk_ops);
376 int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
378 struct rpc_message msg = {
379 .rpc_argp = &req->a_res,
381 return nlm_do_async_call(req, proc, &msg, tk_ops);
385 * NLM client asynchronous call.
387 * Note that although the calls are asynchronous, and are therefore
388 * guaranteed to complete, we still always attempt to wait for
389 * completion in order to be able to correctly track the lock
390 * state.
392 static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
394 struct rpc_message msg = {
395 .rpc_argp = &req->a_args,
396 .rpc_resp = &req->a_res,
397 .rpc_cred = cred,
399 struct rpc_task *task;
400 int err;
402 task = __nlm_async_call(req, proc, &msg, tk_ops);
403 if (IS_ERR(task))
404 return PTR_ERR(task);
405 err = rpc_wait_for_completion_task(task);
406 rpc_put_task(task);
407 return err;
411 * TEST for the presence of a conflicting lock
413 static int
414 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
416 int status;
418 status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST);
419 if (status < 0)
420 goto out;
422 switch (req->a_res.status) {
423 case nlm_granted:
424 fl->fl_type = F_UNLCK;
425 break;
426 case nlm_lck_denied:
428 * Report the conflicting lock back to the application.
430 fl->fl_start = req->a_res.lock.fl.fl_start;
431 fl->fl_end = req->a_res.lock.fl.fl_end;
432 fl->fl_type = req->a_res.lock.fl.fl_type;
433 fl->fl_pid = 0;
434 break;
435 default:
436 status = nlm_stat_to_errno(req->a_res.status);
438 out:
439 nlm_release_call(req);
440 return status;
443 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
445 spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
446 new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
447 new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
448 list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
449 spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
452 static void nlmclnt_locks_release_private(struct file_lock *fl)
454 spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
455 list_del(&fl->fl_u.nfs_fl.list);
456 spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
457 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
460 static const struct file_lock_operations nlmclnt_lock_ops = {
461 .fl_copy_lock = nlmclnt_locks_copy_lock,
462 .fl_release_private = nlmclnt_locks_release_private,
465 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
467 BUG_ON(fl->fl_ops != NULL);
468 fl->fl_u.nfs_fl.state = 0;
469 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
470 INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
471 fl->fl_ops = &nlmclnt_lock_ops;
474 static int do_vfs_lock(struct file_lock *fl)
476 int res = 0;
477 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
478 case FL_POSIX:
479 res = posix_lock_file_wait(fl->fl_file, fl);
480 break;
481 case FL_FLOCK:
482 res = flock_lock_file_wait(fl->fl_file, fl);
483 break;
484 default:
485 BUG();
487 return res;
491 * LOCK: Try to create a lock
493 * Programmer Harassment Alert
495 * When given a blocking lock request in a sync RPC call, the HPUX lockd
496 * will faithfully return LCK_BLOCKED but never cares to notify us when
497 * the lock could be granted. This way, our local process could hang
498 * around forever waiting for the callback.
500 * Solution A: Implement busy-waiting
501 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
503 * For now I am implementing solution A, because I hate the idea of
504 * re-implementing lockd for a third time in two months. The async
505 * calls shouldn't be too hard to do, however.
507 * This is one of the lovely things about standards in the NFS area:
508 * they're so soft and squishy you can't really blame HP for doing this.
510 static int
511 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
513 struct rpc_cred *cred = nfs_file_cred(fl->fl_file);
514 struct nlm_host *host = req->a_host;
515 struct nlm_res *resp = &req->a_res;
516 struct nlm_wait *block = NULL;
517 unsigned char fl_flags = fl->fl_flags;
518 unsigned char fl_type;
519 int status = -ENOLCK;
521 if (nsm_monitor(host) < 0)
522 goto out;
523 req->a_args.state = nsm_local_state;
525 fl->fl_flags |= FL_ACCESS;
526 status = do_vfs_lock(fl);
527 fl->fl_flags = fl_flags;
528 if (status < 0)
529 goto out;
531 block = nlmclnt_prepare_block(host, fl);
532 again:
534 * Initialise resp->status to a valid non-zero value,
535 * since 0 == nlm_lck_granted
537 resp->status = nlm_lck_blocked;
538 for(;;) {
539 /* Reboot protection */
540 fl->fl_u.nfs_fl.state = host->h_state;
541 status = nlmclnt_call(cred, req, NLMPROC_LOCK);
542 if (status < 0)
543 break;
544 /* Did a reclaimer thread notify us of a server reboot? */
545 if (resp->status == nlm_lck_denied_grace_period)
546 continue;
547 if (resp->status != nlm_lck_blocked)
548 break;
549 /* Wait on an NLM blocking lock */
550 status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT);
551 if (status < 0)
552 break;
553 if (resp->status != nlm_lck_blocked)
554 break;
557 /* if we were interrupted while blocking, then cancel the lock request
558 * and exit
560 if (resp->status == nlm_lck_blocked) {
561 if (!req->a_args.block)
562 goto out_unlock;
563 if (nlmclnt_cancel(host, req->a_args.block, fl) == 0)
564 goto out_unblock;
567 if (resp->status == nlm_granted) {
568 down_read(&host->h_rwsem);
569 /* Check whether or not the server has rebooted */
570 if (fl->fl_u.nfs_fl.state != host->h_state) {
571 up_read(&host->h_rwsem);
572 goto again;
574 /* Ensure the resulting lock will get added to granted list */
575 fl->fl_flags |= FL_SLEEP;
576 if (do_vfs_lock(fl) < 0)
577 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);
578 up_read(&host->h_rwsem);
579 fl->fl_flags = fl_flags;
580 status = 0;
582 if (status < 0)
583 goto out_unlock;
585 * EAGAIN doesn't make sense for sleeping locks, and in some
586 * cases NLM_LCK_DENIED is returned for a permanent error. So
587 * turn it into an ENOLCK.
589 if (resp->status == nlm_lck_denied && (fl_flags & FL_SLEEP))
590 status = -ENOLCK;
591 else
592 status = nlm_stat_to_errno(resp->status);
593 out_unblock:
594 nlmclnt_finish_block(block);
595 out:
596 nlm_release_call(req);
597 return status;
598 out_unlock:
599 /* Fatal error: ensure that we remove the lock altogether */
600 dprintk("lockd: lock attempt ended in fatal error.\n"
601 " Attempting to unlock.\n");
602 nlmclnt_finish_block(block);
603 fl_type = fl->fl_type;
604 fl->fl_type = F_UNLCK;
605 down_read(&host->h_rwsem);
606 do_vfs_lock(fl);
607 up_read(&host->h_rwsem);
608 fl->fl_type = fl_type;
609 fl->fl_flags = fl_flags;
610 nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
611 return status;
615 * RECLAIM: Try to reclaim a lock
618 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
620 struct nlm_rqst reqst, *req;
621 int status;
623 req = &reqst;
624 memset(req, 0, sizeof(*req));
625 locks_init_lock(&req->a_args.lock.fl);
626 locks_init_lock(&req->a_res.lock.fl);
627 req->a_host = host;
628 req->a_flags = 0;
630 /* Set up the argument struct */
631 nlmclnt_setlockargs(req, fl);
632 req->a_args.reclaim = 1;
634 status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK);
635 if (status >= 0 && req->a_res.status == nlm_granted)
636 return 0;
638 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
639 "(errno %d, status %d)\n", fl->fl_pid,
640 status, ntohl(req->a_res.status));
643 * FIXME: This is a serious failure. We can
645 * a. Ignore the problem
646 * b. Send the owning process some signal (Linux doesn't have
647 * SIGLOST, though...)
648 * c. Retry the operation
650 * Until someone comes up with a simple implementation
651 * for b or c, I'll choose option a.
654 return -ENOLCK;
658 * UNLOCK: remove an existing lock
660 static int
661 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
663 struct nlm_host *host = req->a_host;
664 struct nlm_res *resp = &req->a_res;
665 int status;
666 unsigned char fl_flags = fl->fl_flags;
669 * Note: the server is supposed to either grant us the unlock
670 * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
671 * case, we want to unlock.
673 fl->fl_flags |= FL_EXISTS;
674 down_read(&host->h_rwsem);
675 status = do_vfs_lock(fl);
676 up_read(&host->h_rwsem);
677 fl->fl_flags = fl_flags;
678 if (status == -ENOENT) {
679 status = 0;
680 goto out;
683 atomic_inc(&req->a_count);
684 status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
685 NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
686 if (status < 0)
687 goto out;
689 if (resp->status == nlm_granted)
690 goto out;
692 if (resp->status != nlm_lck_denied_nolocks)
693 printk("lockd: unexpected unlock status: %d\n", resp->status);
694 /* What to do now? I'm out of my depth... */
695 status = -ENOLCK;
696 out:
697 nlm_release_call(req);
698 return status;
701 static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
703 struct nlm_rqst *req = data;
704 u32 status = ntohl(req->a_res.status);
706 if (RPC_ASSASSINATED(task))
707 goto die;
709 if (task->tk_status < 0) {
710 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
711 goto retry_rebind;
713 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
714 rpc_delay(task, NLMCLNT_GRACE_WAIT);
715 goto retry_unlock;
717 if (status != NLM_LCK_GRANTED)
718 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
719 die:
720 return;
721 retry_rebind:
722 nlm_rebind_host(req->a_host);
723 retry_unlock:
724 rpc_restart_call(task);
727 static const struct rpc_call_ops nlmclnt_unlock_ops = {
728 .rpc_call_done = nlmclnt_unlock_callback,
729 .rpc_release = nlmclnt_rpc_release,
733 * Cancel a blocked lock request.
734 * We always use an async RPC call for this in order not to hang a
735 * process that has been Ctrl-C'ed.
737 static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
739 struct nlm_rqst *req;
740 int status;
742 dprintk("lockd: blocking lock attempt was interrupted by a signal.\n"
743 " Attempting to cancel lock.\n");
745 req = nlm_alloc_call(nlm_get_host(host));
746 if (!req)
747 return -ENOMEM;
748 req->a_flags = RPC_TASK_ASYNC;
750 nlmclnt_setlockargs(req, fl);
751 req->a_args.block = block;
753 atomic_inc(&req->a_count);
754 status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
755 NLMPROC_CANCEL, &nlmclnt_cancel_ops);
756 if (status == 0 && req->a_res.status == nlm_lck_denied)
757 status = -ENOLCK;
758 nlm_release_call(req);
759 return status;
762 static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
764 struct nlm_rqst *req = data;
765 u32 status = ntohl(req->a_res.status);
767 if (RPC_ASSASSINATED(task))
768 goto die;
770 if (task->tk_status < 0) {
771 dprintk("lockd: CANCEL call error %d, retrying.\n",
772 task->tk_status);
773 goto retry_cancel;
776 dprintk("lockd: cancel status %u (task %u)\n",
777 status, task->tk_pid);
779 switch (status) {
780 case NLM_LCK_GRANTED:
781 case NLM_LCK_DENIED_GRACE_PERIOD:
782 case NLM_LCK_DENIED:
783 /* Everything's good */
784 break;
785 case NLM_LCK_DENIED_NOLOCKS:
786 dprintk("lockd: CANCEL failed (server has no locks)\n");
787 goto retry_cancel;
788 default:
789 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
790 status);
793 die:
794 return;
796 retry_cancel:
797 /* Don't ever retry more than 3 times */
798 if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
799 goto die;
800 nlm_rebind_host(req->a_host);
801 rpc_restart_call(task);
802 rpc_delay(task, 30 * HZ);
805 static const struct rpc_call_ops nlmclnt_cancel_ops = {
806 .rpc_call_done = nlmclnt_cancel_callback,
807 .rpc_release = nlmclnt_rpc_release,
811 * Convert an NLM status code to a generic kernel errno
813 static int
814 nlm_stat_to_errno(__be32 status)
816 switch(ntohl(status)) {
817 case NLM_LCK_GRANTED:
818 return 0;
819 case NLM_LCK_DENIED:
820 return -EAGAIN;
821 case NLM_LCK_DENIED_NOLOCKS:
822 case NLM_LCK_DENIED_GRACE_PERIOD:
823 return -ENOLCK;
824 case NLM_LCK_BLOCKED:
825 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
826 return -ENOLCK;
827 #ifdef CONFIG_LOCKD_V4
828 case NLM_DEADLCK:
829 return -EDEADLK;
830 case NLM_ROFS:
831 return -EROFS;
832 case NLM_STALE_FH:
833 return -ESTALE;
834 case NLM_FBIG:
835 return -EOVERFLOW;
836 case NLM_FAILED:
837 return -ENOLCK;
838 #endif
840 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
841 return -ENOLCK;