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-rw-r--r--fs/lockd/clntproc.c820
1 files changed, 820 insertions, 0 deletions
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
new file mode 100644
index 000000000000..a4407619b1f1
--- /dev/null
+++ b/fs/lockd/clntproc.c
@@ -0,0 +1,820 @@
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
25static int nlmclnt_test(struct nlm_rqst *, struct file_lock *);
26static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
27static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
28static void nlmclnt_unlock_callback(struct rpc_task *);
29static void nlmclnt_cancel_callback(struct rpc_task *);
30static int nlm_stat_to_errno(u32 stat);
31static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
32
33/*
34 * Cookie counter for NLM requests
35 */
36static u32 nlm_cookie = 0x1234;
37
38static 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
46static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
47{
48 atomic_inc(&lockowner->count);
49 return lockowner;
50}
51
52static 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
62static 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
72static 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
81static 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
92static 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 */
122static 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
137static 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 */
149int
150nlmclnt_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
173void
174nlmclnt_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 */
190int
191nlmclnt_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(&current->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(&current->blocked); /* Mask all signals */
238 recalc_sigpending();
239 spin_unlock_irqrestore(&current->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(&current->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(&current->sighand->siglock, flags);
273 current->blocked = oldset;
274 recalc_sigpending();
275 spin_unlock_irqrestore(&current->sighand->siglock, flags);
276
277done:
278 dprintk("lockd: clnt proc returns %d\n", status);
279 nlm_release_host(host);
280 return status;
281}
282EXPORT_SYMBOL(nlmclnt_proc);
283
284/*
285 * Allocate an NLM RPC call struct
286 */
287struct nlm_rqst *
288nlmclnt_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
307static 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(PF_FREEZE);
316 if (!signalled ())
317 status = 0;
318 }
319 finish_wait(queue, &wait);
320 return status;
321}
322
323/*
324 * Generic NLM call
325 */
326static int
327nlmclnt_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
387in_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 */
403int
404nlmsvc_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
428static int
429nlmclnt_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 */
461static int
462nlmclnt_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
487static 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
493static 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
499static 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
504static 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
513static 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 */
551static int
552nlmclnt_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 int status;
557
558 if (!host->h_monitored && nsm_monitor(host) < 0) {
559 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
560 host->h_name);
561 status = -ENOLCK;
562 goto out;
563 }
564
565 do {
566 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
567 if (resp->status != NLM_LCK_BLOCKED)
568 break;
569 status = nlmclnt_block(host, fl, &resp->status);
570 }
571 if (status < 0)
572 goto out;
573 } while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
574
575 if (resp->status == NLM_LCK_GRANTED) {
576 fl->fl_u.nfs_fl.state = host->h_state;
577 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
578 fl->fl_flags |= FL_SLEEP;
579 do_vfs_lock(fl);
580 }
581 status = nlm_stat_to_errno(resp->status);
582out:
583 nlmclnt_release_lockargs(req);
584 return status;
585}
586
587/*
588 * RECLAIM: Try to reclaim a lock
589 */
590int
591nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
592{
593 struct nlm_rqst reqst, *req;
594 int status;
595
596 req = &reqst;
597 memset(req, 0, sizeof(*req));
598 locks_init_lock(&req->a_args.lock.fl);
599 locks_init_lock(&req->a_res.lock.fl);
600 req->a_host = host;
601 req->a_flags = 0;
602
603 /* Set up the argument struct */
604 nlmclnt_setlockargs(req, fl);
605 req->a_args.reclaim = 1;
606
607 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
608 && req->a_res.status == NLM_LCK_GRANTED)
609 return 0;
610
611 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
612 "(errno %d, status %d)\n", fl->fl_pid,
613 status, req->a_res.status);
614
615 /*
616 * FIXME: This is a serious failure. We can
617 *
618 * a. Ignore the problem
619 * b. Send the owning process some signal (Linux doesn't have
620 * SIGLOST, though...)
621 * c. Retry the operation
622 *
623 * Until someone comes up with a simple implementation
624 * for b or c, I'll choose option a.
625 */
626
627 return -ENOLCK;
628}
629
630/*
631 * UNLOCK: remove an existing lock
632 */
633static int
634nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
635{
636 struct nlm_res *resp = &req->a_res;
637 int status;
638
639 /* Clean the GRANTED flag now so the lock doesn't get
640 * reclaimed while we're stuck in the unlock call. */
641 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
642
643 if (req->a_flags & RPC_TASK_ASYNC) {
644 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
645 nlmclnt_unlock_callback);
646 /* Hrmf... Do the unlock early since locks_remove_posix()
647 * really expects us to free the lock synchronously */
648 do_vfs_lock(fl);
649 if (status < 0) {
650 nlmclnt_release_lockargs(req);
651 kfree(req);
652 }
653 return status;
654 }
655
656 status = nlmclnt_call(req, NLMPROC_UNLOCK);
657 nlmclnt_release_lockargs(req);
658 if (status < 0)
659 return status;
660
661 do_vfs_lock(fl);
662 if (resp->status == NLM_LCK_GRANTED)
663 return 0;
664
665 if (resp->status != NLM_LCK_DENIED_NOLOCKS)
666 printk("lockd: unexpected unlock status: %d\n", resp->status);
667
668 /* What to do now? I'm out of my depth... */
669
670 return -ENOLCK;
671}
672
673static void
674nlmclnt_unlock_callback(struct rpc_task *task)
675{
676 struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
677 int status = req->a_res.status;
678
679 if (RPC_ASSASSINATED(task))
680 goto die;
681
682 if (task->tk_status < 0) {
683 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
684 goto retry_rebind;
685 }
686 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
687 rpc_delay(task, NLMCLNT_GRACE_WAIT);
688 goto retry_unlock;
689 }
690 if (status != NLM_LCK_GRANTED)
691 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
692die:
693 nlm_release_host(req->a_host);
694 nlmclnt_release_lockargs(req);
695 kfree(req);
696 return;
697 retry_rebind:
698 nlm_rebind_host(req->a_host);
699 retry_unlock:
700 rpc_restart_call(task);
701}
702
703/*
704 * Cancel a blocked lock request.
705 * We always use an async RPC call for this in order not to hang a
706 * process that has been Ctrl-C'ed.
707 */
708int
709nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
710{
711 struct nlm_rqst *req;
712 unsigned long flags;
713 sigset_t oldset;
714 int status;
715
716 /* Block all signals while setting up call */
717 spin_lock_irqsave(&current->sighand->siglock, flags);
718 oldset = current->blocked;
719 sigfillset(&current->blocked);
720 recalc_sigpending();
721 spin_unlock_irqrestore(&current->sighand->siglock, flags);
722
723 req = nlmclnt_alloc_call();
724 if (!req)
725 return -ENOMEM;
726 req->a_host = host;
727 req->a_flags = RPC_TASK_ASYNC;
728
729 nlmclnt_setlockargs(req, fl);
730
731 status = nlmclnt_async_call(req, NLMPROC_CANCEL,
732 nlmclnt_cancel_callback);
733 if (status < 0) {
734 nlmclnt_release_lockargs(req);
735 kfree(req);
736 }
737
738 spin_lock_irqsave(&current->sighand->siglock, flags);
739 current->blocked = oldset;
740 recalc_sigpending();
741 spin_unlock_irqrestore(&current->sighand->siglock, flags);
742
743 return status;
744}
745
746static void
747nlmclnt_cancel_callback(struct rpc_task *task)
748{
749 struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
750
751 if (RPC_ASSASSINATED(task))
752 goto die;
753
754 if (task->tk_status < 0) {
755 dprintk("lockd: CANCEL call error %d, retrying.\n",
756 task->tk_status);
757 goto retry_cancel;
758 }
759
760 dprintk("lockd: cancel status %d (task %d)\n",
761 req->a_res.status, task->tk_pid);
762
763 switch (req->a_res.status) {
764 case NLM_LCK_GRANTED:
765 case NLM_LCK_DENIED_GRACE_PERIOD:
766 /* Everything's good */
767 break;
768 case NLM_LCK_DENIED_NOLOCKS:
769 dprintk("lockd: CANCEL failed (server has no locks)\n");
770 goto retry_cancel;
771 default:
772 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
773 req->a_res.status);
774 }
775
776die:
777 nlm_release_host(req->a_host);
778 nlmclnt_release_lockargs(req);
779 kfree(req);
780 return;
781
782retry_cancel:
783 nlm_rebind_host(req->a_host);
784 rpc_restart_call(task);
785 rpc_delay(task, 30 * HZ);
786}
787
788/*
789 * Convert an NLM status code to a generic kernel errno
790 */
791static int
792nlm_stat_to_errno(u32 status)
793{
794 switch(status) {
795 case NLM_LCK_GRANTED:
796 return 0;
797 case NLM_LCK_DENIED:
798 return -EAGAIN;
799 case NLM_LCK_DENIED_NOLOCKS:
800 case NLM_LCK_DENIED_GRACE_PERIOD:
801 return -ENOLCK;
802 case NLM_LCK_BLOCKED:
803 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
804 return -ENOLCK;
805#ifdef CONFIG_LOCKD_V4
806 case NLM_DEADLCK:
807 return -EDEADLK;
808 case NLM_ROFS:
809 return -EROFS;
810 case NLM_STALE_FH:
811 return -ESTALE;
812 case NLM_FBIG:
813 return -EOVERFLOW;
814 case NLM_FAILED:
815 return -ENOLCK;
816#endif
817 }
818 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
819 return -ENOLCK;
820}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-01 14:39:28 -0400