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/types.h>
11 #include <linux/errno.h>
12 #include <linux/fs.h>
13 #include <linux/nfs_fs.h>
14 #include <linux/utsname.h>
15 #include <linux/smp_lock.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/sunrpc/svc.h>
18 #include <linux/lockd/lockd.h>
19 #include <linux/lockd/sm_inter.h>
20 
21 #define NLMDBG_FACILITY		NLMDBG_CLIENT
22 #define NLMCLNT_GRACE_WAIT	(5*HZ)
23 
24 static int	nlmclnt_test(struct nlm_rqst *, struct file_lock *);
25 static int	nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
26 static int	nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
27 static void	nlmclnt_unlock_callback(struct rpc_task *);
28 static void	nlmclnt_cancel_callback(struct rpc_task *);
29 static int	nlm_stat_to_errno(u32 stat);
30 
31 /*
32  * Cookie counter for NLM requests
33  */
34 static u32	nlm_cookie = 0x1234;
35 
nlmclnt_next_cookie(struct nlm_cookie * c)36 static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
37 {
38 	memcpy(c->data, &nlm_cookie, 4);
39 	memset(c->data+4, 0, 4);
40 	c->len=4;
41 	nlm_cookie++;
42 }
43 
44 /*
45  * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
46  */
47 static inline void
nlmclnt_setlockargs(struct nlm_rqst * req,struct file_lock * fl)48 nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
49 {
50 	struct nlm_args	*argp = &req->a_args;
51 	struct nlm_lock	*lock = &argp->lock;
52 
53 	nlmclnt_next_cookie(&argp->cookie);
54 	argp->state   = nsm_local_state;
55 	memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
56 	lock->caller  = system_utsname.nodename;
57 	lock->oh.data = req->a_owner;
58 	lock->oh.len  = sprintf(req->a_owner, "%d@%s",
59 				current->pid, system_utsname.nodename);
60 	locks_copy_lock(&lock->fl, fl);
61 }
62 
63 /*
64  * Initialize arguments for GRANTED call. The nlm_rqst structure
65  * has been cleared already.
66  */
67 int
nlmclnt_setgrantargs(struct nlm_rqst * call,struct nlm_lock * lock)68 nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
69 {
70 	locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
71 	memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
72 	call->a_args.lock.caller = system_utsname.nodename;
73 	call->a_args.lock.oh.len = lock->oh.len;
74 
75 	/* set default data area */
76 	call->a_args.lock.oh.data = call->a_owner;
77 
78 	if (lock->oh.len > NLMCLNT_OHSIZE) {
79 		void *data = kmalloc(lock->oh.len, GFP_KERNEL);
80 		if (!data)
81 			return 0;
82 		call->a_args.lock.oh.data = (u8 *) data;
83 	}
84 
85 	memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
86 	return 1;
87 }
88 
89 void
nlmclnt_freegrantargs(struct nlm_rqst * call)90 nlmclnt_freegrantargs(struct nlm_rqst *call)
91 {
92 	/*
93 	 * Check whether we allocated memory for the owner.
94 	 */
95 	if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
96 		kfree(call->a_args.lock.oh.data);
97 	}
98 }
99 
100 /*
101  * This is the main entry point for the NLM client.
102  */
103 int
nlmclnt_proc(struct inode * inode,int cmd,struct file_lock * fl)104 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
105 {
106 	struct nfs_server	*nfssrv = NFS_SERVER(inode);
107 	struct nlm_host		*host;
108 	struct nlm_rqst		reqst, *call = &reqst;
109 	sigset_t		oldset;
110 	unsigned long		flags;
111 	int			status, proto, vers;
112 
113 	vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
114 	if (NFS_PROTO(inode)->version > 3) {
115 		printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
116 		return -ENOLCK;
117 	}
118 
119 	/* Retrieve transport protocol from NFS client */
120 	proto = NFS_CLIENT(inode)->cl_xprt->prot;
121 
122 	if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
123 		return -ENOLCK;
124 
125 	/* Create RPC client handle if not there, and copy soft
126 	 * and intr flags from NFS client. */
127 	if (host->h_rpcclnt == NULL) {
128 		struct rpc_clnt	*clnt;
129 
130 		/* Bind an rpc client to this host handle (does not
131 		 * perform a portmapper lookup) */
132 		if (!(clnt = nlm_bind_host(host))) {
133 			status = -ENOLCK;
134 			goto done;
135 		}
136 		clnt->cl_softrtry = nfssrv->client->cl_softrtry;
137 		clnt->cl_intr     = nfssrv->client->cl_intr;
138 		clnt->cl_chatty   = nfssrv->client->cl_chatty;
139 	}
140 
141 	/* Keep the old signal mask */
142 	spin_lock_irqsave(&current->sigmask_lock, flags);
143 	oldset = current->blocked;
144 
145 	/* If we're cleaning up locks because the process is exiting,
146 	 * perform the RPC call asynchronously. */
147 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
148 	    && fl->fl_type == F_UNLCK
149 	    && (current->flags & PF_EXITING)) {
150 		sigfillset(&current->blocked);	/* Mask all signals */
151 		recalc_sigpending(current);
152 		spin_unlock_irqrestore(&current->sigmask_lock, flags);
153 
154 		call = nlmclnt_alloc_call();
155 		if (!call) {
156 			status = -ENOMEM;
157 			goto out_restore;
158 		}
159 		call->a_flags = RPC_TASK_ASYNC;
160 	} else {
161 		spin_unlock_irqrestore(&current->sigmask_lock, flags);
162 		memset(call, 0, sizeof(*call));
163 		locks_init_lock(&call->a_args.lock.fl);
164 		locks_init_lock(&call->a_res.lock.fl);
165 	}
166 	call->a_host = host;
167 
168 	/* Set up the argument struct */
169 	nlmclnt_setlockargs(call, fl);
170 
171 	if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
172 		if (fl->fl_type != F_UNLCK) {
173 			call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
174 			status = nlmclnt_lock(call, fl);
175 		} else
176 			status = nlmclnt_unlock(call, fl);
177 	} else if (IS_GETLK(cmd))
178 		status = nlmclnt_test(call, fl);
179 	else
180 		status = -EINVAL;
181 
182 	if (status < 0 && (call->a_flags & RPC_TASK_ASYNC))
183 		kfree(call);
184 
185  out_restore:
186 	spin_lock_irqsave(&current->sigmask_lock, flags);
187 	current->blocked = oldset;
188 	recalc_sigpending(current);
189 	spin_unlock_irqrestore(&current->sigmask_lock, flags);
190 
191 done:
192 	dprintk("lockd: clnt proc returns %d\n", status);
193 	nlm_release_host(host);
194 	return status;
195 }
196 
197 /*
198  * Wait while server is in grace period
199  */
200 static inline int
nlmclnt_grace_wait(struct nlm_host * host)201 nlmclnt_grace_wait(struct nlm_host *host)
202 {
203 	if (!host->h_reclaiming)
204 		interruptible_sleep_on_timeout(&host->h_gracewait, 10*HZ);
205 	else
206 		interruptible_sleep_on(&host->h_gracewait);
207 	return signalled()? -ERESTARTSYS : 0;
208 }
209 
210 /*
211  * Allocate an NLM RPC call struct
212  */
213 struct nlm_rqst *
nlmclnt_alloc_call(void)214 nlmclnt_alloc_call(void)
215 {
216 	struct nlm_rqst	*call;
217 
218 	while (!signalled()) {
219 		call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
220 		if (call) {
221 			memset(call, 0, sizeof(*call));
222 			locks_init_lock(&call->a_args.lock.fl);
223 			locks_init_lock(&call->a_res.lock.fl);
224 			return call;
225 		}
226 		printk("nlmclnt_alloc_call: failed, waiting for memory\n");
227 		current->state = TASK_INTERRUPTIBLE;
228 		schedule_timeout(5*HZ);
229 	}
230 	return NULL;
231 }
232 
233 /*
234  * Generic NLM call
235  */
236 int
nlmclnt_call(struct nlm_rqst * req,u32 proc)237 nlmclnt_call(struct nlm_rqst *req, u32 proc)
238 {
239 	struct nlm_host	*host = req->a_host;
240 	struct rpc_clnt	*clnt;
241 	struct nlm_args	*argp = &req->a_args;
242 	struct nlm_res	*resp = &req->a_res;
243 	struct file	*filp = argp->lock.fl.fl_file;
244 	struct rpc_message msg;
245 	int		status;
246 
247 	dprintk("lockd: call procedure %s on %s\n",
248 			nlm_procname(proc), host->h_name);
249 
250 	msg.rpc_proc = proc;
251 	msg.rpc_argp = argp;
252 	msg.rpc_resp = resp;
253 	if (filp)
254 		msg.rpc_cred = nfs_file_cred(filp);
255 	else
256 		msg.rpc_cred = NULL;
257 
258 	do {
259 		if (host->h_reclaiming && !argp->reclaim) {
260 			interruptible_sleep_on(&host->h_gracewait);
261 			continue;
262 		}
263 
264 		/* If we have no RPC client yet, create one. */
265 		if ((clnt = nlm_bind_host(host)) == NULL)
266 			return -ENOLCK;
267 
268 		/* Perform the RPC call. If an error occurs, try again */
269 		if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
270 			dprintk("lockd: rpc_call returned error %d\n", -status);
271 			switch (status) {
272 			case -EPROTONOSUPPORT:
273 				status = -EINVAL;
274 				break;
275 			case -ECONNREFUSED:
276 			case -ETIMEDOUT:
277 			case -ENOTCONN:
278 				nlm_rebind_host(host);
279 				status = -EAGAIN;
280 				break;
281 			case -ERESTARTSYS:
282 				return signalled () ? -EINTR : status;
283 			default:
284 				break;
285 			}
286 			break;
287 		} else
288 		if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) {
289 			dprintk("lockd: server in grace period\n");
290 			if (argp->reclaim) {
291 				printk(KERN_WARNING
292 				     "lockd: spurious grace period reject?!\n");
293 				return -ENOLCK;
294 			}
295 		} else {
296 			dprintk("lockd: server returns status %d\n", resp->status);
297 			return 0;	/* Okay, call complete */
298 		}
299 
300 		/* Back off a little and try again */
301 		interruptible_sleep_on_timeout(&host->h_gracewait, 15*HZ);
302 
303 		/* When the lock requested by F_SETLKW isn't available,
304 		   we will wait until the request can be satisfied. If
305 		   a signal is received during wait, we should return
306 		   -EINTR. */
307 		if (signalled ()) {
308 			status = -EINTR;
309 			break;
310 		}
311 	} while (1);
312 
313 	return status;
314 }
315 
316 /*
317  * Generic NLM call, async version.
318  */
319 int
nlmsvc_async_call(struct nlm_rqst * req,u32 proc,rpc_action callback)320 nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
321 {
322 	struct nlm_host	*host = req->a_host;
323 	struct rpc_clnt	*clnt;
324 	struct nlm_args	*argp = &req->a_args;
325 	struct nlm_res	*resp = &req->a_res;
326 	struct rpc_message msg;
327 	int		status;
328 
329 	dprintk("lockd: call procedure %s on %s (async)\n",
330 			nlm_procname(proc), host->h_name);
331 
332 	/* If we have no RPC client yet, create one. */
333 	if ((clnt = nlm_bind_host(host)) == NULL)
334 		return -ENOLCK;
335 
336         /* bootstrap and kick off the async RPC call */
337 	msg.rpc_proc = proc;
338 	msg.rpc_argp = argp;
339 	msg.rpc_resp =resp;
340 	msg.rpc_cred = NULL;
341         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
342 
343 	return status;
344 }
345 
346 int
nlmclnt_async_call(struct nlm_rqst * req,u32 proc,rpc_action callback)347 nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
348 {
349 	struct nlm_host	*host = req->a_host;
350 	struct rpc_clnt	*clnt;
351 	struct nlm_args	*argp = &req->a_args;
352 	struct nlm_res	*resp = &req->a_res;
353 	struct file	*file = argp->lock.fl.fl_file;
354 	struct rpc_message msg;
355 	int		status;
356 
357 	dprintk("lockd: call procedure %s on %s (async)\n",
358 			nlm_procname(proc), host->h_name);
359 
360 	/* If we have no RPC client yet, create one. */
361 	if ((clnt = nlm_bind_host(host)) == NULL)
362 		return -ENOLCK;
363 
364         /* bootstrap and kick off the async RPC call */
365 	msg.rpc_proc = proc;
366 	msg.rpc_argp = argp;
367 	msg.rpc_resp =resp;
368 	if (file)
369 		msg.rpc_cred = nfs_file_cred(file);
370 	else
371 		msg.rpc_cred = NULL;
372 	/* Increment host refcount */
373 	nlm_get_host(host);
374         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
375 	if (status < 0)
376 		nlm_release_host(host);
377 	return status;
378 }
379 
380 /*
381  * TEST for the presence of a conflicting lock
382  */
383 static int
nlmclnt_test(struct nlm_rqst * req,struct file_lock * fl)384 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
385 {
386 	int	status;
387 
388 	if ((status = nlmclnt_call(req, NLMPROC_TEST)) < 0)
389 		return status;
390 
391 	status = req->a_res.status;
392 	if (status == NLM_LCK_GRANTED) {
393 		fl->fl_type = F_UNLCK;
394 	} if (status == NLM_LCK_DENIED) {
395 		/*
396 		 * Report the conflicting lock back to the application.
397 		 * FIXME: Is it OK to report the pid back as well?
398 		 */
399 		locks_copy_lock(fl, &req->a_res.lock.fl);
400 		/* fl->fl_pid = 0; */
401 	} else {
402 		return nlm_stat_to_errno(req->a_res.status);
403 	}
404 
405 	return 0;
406 }
407 
408 static
nlmclnt_insert_lock_callback(struct file_lock * fl)409 void nlmclnt_insert_lock_callback(struct file_lock *fl)
410 {
411 	nlm_get_host(fl->fl_u.nfs_fl.host);
412 }
413 static
nlmclnt_remove_lock_callback(struct file_lock * fl)414 void nlmclnt_remove_lock_callback(struct file_lock *fl)
415 {
416 	if (fl->fl_u.nfs_fl.host) {
417 		nlm_release_host(fl->fl_u.nfs_fl.host);
418 		fl->fl_u.nfs_fl.host = NULL;
419 	}
420 }
421 
422 /*
423  * LOCK: Try to create a lock
424  *
425  *			Programmer Harassment Alert
426  *
427  * When given a blocking lock request in a sync RPC call, the HPUX lockd
428  * will faithfully return LCK_BLOCKED but never cares to notify us when
429  * the lock could be granted. This way, our local process could hang
430  * around forever waiting for the callback.
431  *
432  *  Solution A:	Implement busy-waiting
433  *  Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
434  *
435  * For now I am implementing solution A, because I hate the idea of
436  * re-implementing lockd for a third time in two months. The async
437  * calls shouldn't be too hard to do, however.
438  *
439  * This is one of the lovely things about standards in the NFS area:
440  * they're so soft and squishy you can't really blame HP for doing this.
441  */
442 static int
nlmclnt_lock(struct nlm_rqst * req,struct file_lock * fl)443 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
444 {
445 	struct nlm_host	*host = req->a_host;
446 	struct nlm_res	*resp = &req->a_res;
447 	int		status;
448 
449 	if (!host->h_monitored && nsm_monitor(host) < 0) {
450 		printk(KERN_NOTICE "lockd: failed to monitor %s\n",
451 					host->h_name);
452 		return -ENOLCK;
453 	}
454 
455 	do {
456 		if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
457 			if (resp->status != NLM_LCK_BLOCKED)
458 				break;
459 			status = nlmclnt_block(host, fl, &resp->status);
460 		}
461 		if (status < 0)
462 			return status;
463 	} while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
464 
465 	if (resp->status == NLM_LCK_GRANTED) {
466 		fl->fl_u.nfs_fl.state = host->h_state;
467 		fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
468 		fl->fl_u.nfs_fl.host = host;
469 		fl->fl_insert = nlmclnt_insert_lock_callback;
470 		fl->fl_remove = nlmclnt_remove_lock_callback;
471 	}
472 
473 	return nlm_stat_to_errno(resp->status);
474 }
475 
476 /*
477  * RECLAIM: Try to reclaim a lock
478  */
479 int
nlmclnt_reclaim(struct nlm_host * host,struct file_lock * fl)480 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
481 {
482 	struct nlm_rqst reqst, *req;
483 	int		status;
484 
485 	req = &reqst;
486 	memset(req, 0, sizeof(*req));
487 	locks_init_lock(&req->a_args.lock.fl);
488 	locks_init_lock(&req->a_res.lock.fl);
489 	req->a_host  = host;
490 	req->a_flags = 0;
491 
492 	/* Set up the argument struct */
493 	nlmclnt_setlockargs(req, fl);
494 	req->a_args.reclaim = 1;
495 
496 	if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
497 	 && req->a_res.status == NLM_LCK_GRANTED)
498 		return 0;
499 
500 	printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
501 				"(errno %d, status %d)\n", fl->fl_pid,
502 				status, req->a_res.status);
503 
504 	/*
505 	 * FIXME: This is a serious failure. We can
506 	 *
507 	 *  a.	Ignore the problem
508 	 *  b.	Send the owning process some signal (Linux doesn't have
509 	 *	SIGLOST, though...)
510 	 *  c.	Retry the operation
511 	 *
512 	 * Until someone comes up with a simple implementation
513 	 * for b or c, I'll choose option a.
514 	 */
515 
516 	return -ENOLCK;
517 }
518 
519 /*
520  * UNLOCK: remove an existing lock
521  */
522 static int
nlmclnt_unlock(struct nlm_rqst * req,struct file_lock * fl)523 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
524 {
525 	struct nlm_res	*resp = &req->a_res;
526 	int		status;
527 
528 	/* Clean the GRANTED flag now so the lock doesn't get
529 	 * reclaimed while we're stuck in the unlock call. */
530 	fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
531 
532 	if (req->a_flags & RPC_TASK_ASYNC) {
533 		return nlmclnt_async_call(req, NLMPROC_UNLOCK,
534 					nlmclnt_unlock_callback);
535 	}
536 
537 	if ((status = nlmclnt_call(req, NLMPROC_UNLOCK)) < 0)
538 		return status;
539 
540 	if (resp->status == NLM_LCK_GRANTED)
541 		return 0;
542 
543 	if (resp->status != NLM_LCK_DENIED_NOLOCKS)
544 		printk("lockd: unexpected unlock status: %d\n", resp->status);
545 
546 	/* What to do now? I'm out of my depth... */
547 
548 	return -ENOLCK;
549 }
550 
551 static void
nlmclnt_unlock_callback(struct rpc_task * task)552 nlmclnt_unlock_callback(struct rpc_task *task)
553 {
554 	struct nlm_rqst	*req = (struct nlm_rqst *) task->tk_calldata;
555 	int		status = req->a_res.status;
556 
557 	if (RPC_ASSASSINATED(task))
558 		goto die;
559 
560 	if (task->tk_status < 0) {
561 		dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
562 		goto retry_rebind;
563 	}
564 	if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
565 		rpc_delay(task, NLMCLNT_GRACE_WAIT);
566 		goto retry_unlock;
567 	}
568 	if (status != NLM_LCK_GRANTED)
569 		printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
570 
571 die:
572 	nlm_release_host(req->a_host);
573 	kfree(req);
574 	return;
575  retry_rebind:
576 	nlm_rebind_host(req->a_host);
577  retry_unlock:
578 	rpc_restart_call(task);
579 }
580 
581 /*
582  * Cancel a blocked lock request.
583  * We always use an async RPC call for this in order not to hang a
584  * process that has been Ctrl-C'ed.
585  */
586 int
nlmclnt_cancel(struct nlm_host * host,struct file_lock * fl)587 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
588 {
589 	struct nlm_rqst	*req;
590 	unsigned long	flags;
591 	sigset_t	oldset;
592 	int		status;
593 
594 	/* Block all signals while setting up call */
595 	spin_lock_irqsave(&current->sigmask_lock, flags);
596 	oldset = current->blocked;
597 	sigfillset(&current->blocked);
598 	recalc_sigpending(current);
599 	spin_unlock_irqrestore(&current->sigmask_lock, flags);
600 
601 	req = nlmclnt_alloc_call();
602 	if (!req)
603 		return -ENOMEM;
604 	req->a_host  = host;
605 	req->a_flags = RPC_TASK_ASYNC;
606 
607 	nlmclnt_setlockargs(req, fl);
608 
609 	status = nlmclnt_async_call(req, NLMPROC_CANCEL,
610 					nlmclnt_cancel_callback);
611 	if (status < 0)
612 		kfree(req);
613 
614 	spin_lock_irqsave(&current->sigmask_lock, flags);
615 	current->blocked = oldset;
616 	recalc_sigpending(current);
617 	spin_unlock_irqrestore(&current->sigmask_lock, flags);
618 
619 	return status;
620 }
621 
622 static void
nlmclnt_cancel_callback(struct rpc_task * task)623 nlmclnt_cancel_callback(struct rpc_task *task)
624 {
625 	struct nlm_rqst	*req = (struct nlm_rqst *) task->tk_calldata;
626 
627 	if (RPC_ASSASSINATED(task))
628 		goto die;
629 
630 	if (task->tk_status < 0) {
631 		dprintk("lockd: CANCEL call error %d, retrying.\n",
632 					task->tk_status);
633 		goto retry_cancel;
634 	}
635 
636 	dprintk("lockd: cancel status %d (task %d)\n",
637 			req->a_res.status, task->tk_pid);
638 
639 	switch (req->a_res.status) {
640 	case NLM_LCK_GRANTED:
641 	case NLM_LCK_DENIED_GRACE_PERIOD:
642 		/* Everything's good */
643 		break;
644 	case NLM_LCK_DENIED_NOLOCKS:
645 		dprintk("lockd: CANCEL failed (server has no locks)\n");
646 		goto retry_cancel;
647 	default:
648 		printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
649 			req->a_res.status);
650 	}
651 
652 die:
653 	nlm_release_host(req->a_host);
654 	kfree(req);
655 	return;
656 
657 retry_cancel:
658 	nlm_rebind_host(req->a_host);
659 	rpc_restart_call(task);
660 	rpc_delay(task, 30 * HZ);
661 }
662 
663 /*
664  * Convert an NLM status code to a generic kernel errno
665  */
666 static int
nlm_stat_to_errno(u32 status)667 nlm_stat_to_errno(u32 status)
668 {
669 	switch(status) {
670 	case NLM_LCK_GRANTED:
671 		return 0;
672 	case NLM_LCK_DENIED:
673 		return -EAGAIN;
674 	case NLM_LCK_DENIED_NOLOCKS:
675 	case NLM_LCK_DENIED_GRACE_PERIOD:
676 		return -ENOLCK;
677 	case NLM_LCK_BLOCKED:
678 		printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
679 		return -ENOLCK;
680 #ifdef CONFIG_LOCKD_V4
681 	case NLM_DEADLCK:
682 		return -EDEADLK;
683 	case NLM_ROFS:
684 		return -EROFS;
685 	case NLM_STALE_FH:
686 		return -ESTALE;
687 	case NLM_FBIG:
688 		return -EOVERFLOW;
689 	case NLM_FAILED:
690 		return -ENOLCK;
691 #endif
692 	}
693 	printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
694 	return -ENOLCK;
695 }
696