blob: 14b3ce87fa29cd96162678fb754936e22c99caec [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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)
Trond Myklebustecdbf762005-06-22 17:16:31 +000024#define NLMCLNT_POLL_TIMEOUT (30*HZ)
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26static int nlmclnt_test(struct nlm_rqst *, struct file_lock *);
27static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
28static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
29static void nlmclnt_unlock_callback(struct rpc_task *);
30static void nlmclnt_cancel_callback(struct rpc_task *);
31static int nlm_stat_to_errno(u32 stat);
32static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
33
34/*
35 * Cookie counter for NLM requests
36 */
37static u32 nlm_cookie = 0x1234;
38
39static 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
47static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
48{
49 atomic_inc(&lockowner->count);
50 return lockowner;
51}
52
53static 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
63static 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
73static 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
82static 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
93static 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 */
123static 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
138static 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 */
150int
151nlmclnt_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
174void
175nlmclnt_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 */
191int
192nlmclnt_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
278done:
279 dprintk("lockd: clnt proc returns %d\n", status);
280 nlm_release_host(host);
281 return status;
282}
283EXPORT_SYMBOL(nlmclnt_proc);
284
285/*
286 * Allocate an NLM RPC call struct
287 */
288struct nlm_rqst *
289nlmclnt_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 current->state = TASK_INTERRUPTIBLE;
303 schedule_timeout(5*HZ);
304 }
305 return NULL;
306}
307
308static int nlm_wait_on_grace(wait_queue_head_t *queue)
309{
310 DEFINE_WAIT(wait);
311 int status = -EINTR;
312
313 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
314 if (!signalled ()) {
315 schedule_timeout(NLMCLNT_GRACE_WAIT);
Christoph Lameter3e1d1d22005-06-24 23:13:50 -0700316 try_to_freeze();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 if (!signalled ())
318 status = 0;
319 }
320 finish_wait(queue, &wait);
321 return status;
322}
323
324/*
325 * Generic NLM call
326 */
327static int
328nlmclnt_call(struct nlm_rqst *req, u32 proc)
329{
330 struct nlm_host *host = req->a_host;
331 struct rpc_clnt *clnt;
332 struct nlm_args *argp = &req->a_args;
333 struct nlm_res *resp = &req->a_res;
334 struct rpc_message msg = {
335 .rpc_argp = argp,
336 .rpc_resp = resp,
337 };
338 int status;
339
340 dprintk("lockd: call procedure %d on %s\n",
341 (int)proc, host->h_name);
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
388in_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 */
404int
405nlmsvc_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
429static int
430nlmclnt_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 rpc_message msg = {
437 .rpc_argp = argp,
438 .rpc_resp = resp,
439 };
440 int status;
441
442 dprintk("lockd: call procedure %d on %s (async)\n",
443 (int)proc, host->h_name);
444
445 /* If we have no RPC client yet, create one. */
446 if ((clnt = nlm_bind_host(host)) == NULL)
447 return -ENOLCK;
448 msg.rpc_proc = &clnt->cl_procinfo[proc];
449
450 /* Increment host refcount */
451 nlm_get_host(host);
452 /* bootstrap and kick off the async RPC call */
453 status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
454 if (status < 0)
455 nlm_release_host(host);
456 return status;
457}
458
459/*
460 * TEST for the presence of a conflicting lock
461 */
462static int
463nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
464{
465 int status;
466
467 status = nlmclnt_call(req, NLMPROC_TEST);
468 nlmclnt_release_lockargs(req);
469 if (status < 0)
470 return status;
471
472 status = req->a_res.status;
473 if (status == NLM_LCK_GRANTED) {
474 fl->fl_type = F_UNLCK;
475 } if (status == NLM_LCK_DENIED) {
476 /*
477 * Report the conflicting lock back to the application.
478 */
479 locks_copy_lock(fl, &req->a_res.lock.fl);
480 fl->fl_pid = 0;
481 } else {
482 return nlm_stat_to_errno(req->a_res.status);
483 }
484
485 return 0;
486}
487
488static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
489{
490 memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
491 nlm_get_lockowner(new->fl_u.nfs_fl.owner);
492}
493
494static void nlmclnt_locks_release_private(struct file_lock *fl)
495{
496 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
497 fl->fl_ops = NULL;
498}
499
500static struct file_lock_operations nlmclnt_lock_ops = {
501 .fl_copy_lock = nlmclnt_locks_copy_lock,
502 .fl_release_private = nlmclnt_locks_release_private,
503};
504
505static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
506{
507 BUG_ON(fl->fl_ops != NULL);
508 fl->fl_u.nfs_fl.state = 0;
509 fl->fl_u.nfs_fl.flags = 0;
510 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
511 fl->fl_ops = &nlmclnt_lock_ops;
512}
513
514static void do_vfs_lock(struct file_lock *fl)
515{
516 int res = 0;
517 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
518 case FL_POSIX:
519 res = posix_lock_file_wait(fl->fl_file, fl);
520 break;
521 case FL_FLOCK:
522 res = flock_lock_file_wait(fl->fl_file, fl);
523 break;
524 default:
525 BUG();
526 }
527 if (res < 0)
528 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
529 __FUNCTION__);
530}
531
532/*
533 * LOCK: Try to create a lock
534 *
535 * Programmer Harassment Alert
536 *
537 * When given a blocking lock request in a sync RPC call, the HPUX lockd
538 * will faithfully return LCK_BLOCKED but never cares to notify us when
539 * the lock could be granted. This way, our local process could hang
540 * around forever waiting for the callback.
541 *
542 * Solution A: Implement busy-waiting
543 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
544 *
545 * For now I am implementing solution A, because I hate the idea of
546 * re-implementing lockd for a third time in two months. The async
547 * calls shouldn't be too hard to do, however.
548 *
549 * This is one of the lovely things about standards in the NFS area:
550 * they're so soft and squishy you can't really blame HP for doing this.
551 */
552static int
553nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
554{
555 struct nlm_host *host = req->a_host;
556 struct nlm_res *resp = &req->a_res;
Trond Myklebustecdbf762005-06-22 17:16:31 +0000557 long timeout;
558 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 if (!host->h_monitored && nsm_monitor(host) < 0) {
561 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
562 host->h_name);
563 status = -ENOLCK;
564 goto out;
565 }
566
Trond Myklebustecdbf762005-06-22 17:16:31 +0000567 if (req->a_args.block) {
568 status = nlmclnt_prepare_block(req, host, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 if (status < 0)
570 goto out;
Trond Myklebustecdbf762005-06-22 17:16:31 +0000571 }
572 for(;;) {
573 status = nlmclnt_call(req, NLMPROC_LOCK);
574 if (status < 0)
575 goto out_unblock;
576 if (resp->status != NLM_LCK_BLOCKED)
577 break;
578 /* Wait on an NLM blocking lock */
579 timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT);
580 /* Did a reclaimer thread notify us of a server reboot? */
581 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD)
582 continue;
583 if (resp->status != NLM_LCK_BLOCKED)
584 break;
585 if (timeout >= 0)
586 continue;
587 /* We were interrupted. Send a CANCEL request to the server
588 * and exit
589 */
590 status = (int)timeout;
591 goto out_unblock;
592 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
594 if (resp->status == NLM_LCK_GRANTED) {
595 fl->fl_u.nfs_fl.state = host->h_state;
596 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
597 fl->fl_flags |= FL_SLEEP;
598 do_vfs_lock(fl);
599 }
600 status = nlm_stat_to_errno(resp->status);
Trond Myklebustecdbf762005-06-22 17:16:31 +0000601out_unblock:
602 nlmclnt_finish_block(req);
603 /* Cancel the blocked request if it is still pending */
604 if (resp->status == NLM_LCK_BLOCKED)
605 nlmclnt_cancel(host, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606out:
607 nlmclnt_release_lockargs(req);
608 return status;
609}
610
611/*
612 * RECLAIM: Try to reclaim a lock
613 */
614int
615nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
616{
617 struct nlm_rqst reqst, *req;
618 int status;
619
620 req = &reqst;
621 memset(req, 0, sizeof(*req));
622 locks_init_lock(&req->a_args.lock.fl);
623 locks_init_lock(&req->a_res.lock.fl);
624 req->a_host = host;
625 req->a_flags = 0;
626
627 /* Set up the argument struct */
628 nlmclnt_setlockargs(req, fl);
629 req->a_args.reclaim = 1;
630
631 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
632 && req->a_res.status == NLM_LCK_GRANTED)
633 return 0;
634
635 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
636 "(errno %d, status %d)\n", fl->fl_pid,
637 status, req->a_res.status);
638
639 /*
640 * FIXME: This is a serious failure. We can
641 *
642 * a. Ignore the problem
643 * b. Send the owning process some signal (Linux doesn't have
644 * SIGLOST, though...)
645 * c. Retry the operation
646 *
647 * Until someone comes up with a simple implementation
648 * for b or c, I'll choose option a.
649 */
650
651 return -ENOLCK;
652}
653
654/*
655 * UNLOCK: remove an existing lock
656 */
657static int
658nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
659{
660 struct nlm_res *resp = &req->a_res;
661 int status;
662
663 /* Clean the GRANTED flag now so the lock doesn't get
664 * reclaimed while we're stuck in the unlock call. */
665 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
666
667 if (req->a_flags & RPC_TASK_ASYNC) {
668 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
669 nlmclnt_unlock_callback);
670 /* Hrmf... Do the unlock early since locks_remove_posix()
671 * really expects us to free the lock synchronously */
672 do_vfs_lock(fl);
673 if (status < 0) {
674 nlmclnt_release_lockargs(req);
675 kfree(req);
676 }
677 return status;
678 }
679
680 status = nlmclnt_call(req, NLMPROC_UNLOCK);
681 nlmclnt_release_lockargs(req);
682 if (status < 0)
683 return status;
684
685 do_vfs_lock(fl);
686 if (resp->status == NLM_LCK_GRANTED)
687 return 0;
688
689 if (resp->status != NLM_LCK_DENIED_NOLOCKS)
690 printk("lockd: unexpected unlock status: %d\n", resp->status);
691
692 /* What to do now? I'm out of my depth... */
693
694 return -ENOLCK;
695}
696
697static void
698nlmclnt_unlock_callback(struct rpc_task *task)
699{
700 struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
701 int status = req->a_res.status;
702
703 if (RPC_ASSASSINATED(task))
704 goto die;
705
706 if (task->tk_status < 0) {
707 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
708 goto retry_rebind;
709 }
710 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
711 rpc_delay(task, NLMCLNT_GRACE_WAIT);
712 goto retry_unlock;
713 }
714 if (status != NLM_LCK_GRANTED)
715 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
716die:
717 nlm_release_host(req->a_host);
718 nlmclnt_release_lockargs(req);
719 kfree(req);
720 return;
721 retry_rebind:
722 nlm_rebind_host(req->a_host);
723 retry_unlock:
724 rpc_restart_call(task);
725}
726
727/*
728 * Cancel a blocked lock request.
729 * We always use an async RPC call for this in order not to hang a
730 * process that has been Ctrl-C'ed.
731 */
732int
733nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
734{
735 struct nlm_rqst *req;
736 unsigned long flags;
737 sigset_t oldset;
738 int status;
739
740 /* Block all signals while setting up call */
741 spin_lock_irqsave(&current->sighand->siglock, flags);
742 oldset = current->blocked;
743 sigfillset(&current->blocked);
744 recalc_sigpending();
745 spin_unlock_irqrestore(&current->sighand->siglock, flags);
746
747 req = nlmclnt_alloc_call();
748 if (!req)
749 return -ENOMEM;
750 req->a_host = host;
751 req->a_flags = RPC_TASK_ASYNC;
752
753 nlmclnt_setlockargs(req, fl);
754
755 status = nlmclnt_async_call(req, NLMPROC_CANCEL,
756 nlmclnt_cancel_callback);
757 if (status < 0) {
758 nlmclnt_release_lockargs(req);
759 kfree(req);
760 }
761
762 spin_lock_irqsave(&current->sighand->siglock, flags);
763 current->blocked = oldset;
764 recalc_sigpending();
765 spin_unlock_irqrestore(&current->sighand->siglock, flags);
766
767 return status;
768}
769
770static void
771nlmclnt_cancel_callback(struct rpc_task *task)
772{
773 struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
774
775 if (RPC_ASSASSINATED(task))
776 goto die;
777
778 if (task->tk_status < 0) {
779 dprintk("lockd: CANCEL call error %d, retrying.\n",
780 task->tk_status);
781 goto retry_cancel;
782 }
783
784 dprintk("lockd: cancel status %d (task %d)\n",
785 req->a_res.status, task->tk_pid);
786
787 switch (req->a_res.status) {
788 case NLM_LCK_GRANTED:
789 case NLM_LCK_DENIED_GRACE_PERIOD:
790 /* Everything's good */
791 break;
792 case NLM_LCK_DENIED_NOLOCKS:
793 dprintk("lockd: CANCEL failed (server has no locks)\n");
794 goto retry_cancel;
795 default:
796 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
797 req->a_res.status);
798 }
799
800die:
801 nlm_release_host(req->a_host);
802 nlmclnt_release_lockargs(req);
803 kfree(req);
804 return;
805
806retry_cancel:
807 nlm_rebind_host(req->a_host);
808 rpc_restart_call(task);
809 rpc_delay(task, 30 * HZ);
810}
811
812/*
813 * Convert an NLM status code to a generic kernel errno
814 */
815static int
816nlm_stat_to_errno(u32 status)
817{
818 switch(status) {
819 case NLM_LCK_GRANTED:
820 return 0;
821 case NLM_LCK_DENIED:
822 return -EAGAIN;
823 case NLM_LCK_DENIED_NOLOCKS:
824 case NLM_LCK_DENIED_GRACE_PERIOD:
825 return -ENOLCK;
826 case NLM_LCK_BLOCKED:
827 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
828 return -ENOLCK;
829#ifdef CONFIG_LOCKD_V4
830 case NLM_DEADLCK:
831 return -EDEADLK;
832 case NLM_ROFS:
833 return -EROFS;
834 case NLM_STALE_FH:
835 return -ESTALE;
836 case NLM_FBIG:
837 return -EOVERFLOW;
838 case NLM_FAILED:
839 return -ENOLCK;
840#endif
841 }
842 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
843 return -ENOLCK;
844}