Commit | Line | Data |
---|---|---|
1da177e4 LT |
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) | |
ecdbf769 | 24 | #define NLMCLNT_POLL_TIMEOUT (30*HZ) |
1da177e4 LT |
25 | |
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 void nlmclnt_unlock_callback(struct rpc_task *); | |
30 | static void nlmclnt_cancel_callback(struct rpc_task *); | |
31 | static int nlm_stat_to_errno(u32 stat); | |
32 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); | |
33 | ||
34 | /* | |
35 | * Cookie counter for NLM requests | |
36 | */ | |
37 | static u32 nlm_cookie = 0x1234; | |
38 | ||
39 | static 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 | ||
47 | static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner) | |
48 | { | |
49 | atomic_inc(&lockowner->count); | |
50 | return lockowner; | |
51 | } | |
52 | ||
53 | static 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 | ||
63 | static 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 | ||
73 | static 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 | ||
82 | static 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 | ||
93 | static 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 | */ | |
123 | static 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 | ||
138 | static 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 | */ | |
150 | int | |
151 | nlmclnt_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 | ||
174 | void | |
175 | nlmclnt_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 | */ | |
191 | int | |
192 | nlmclnt_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(¤t->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(¤t->blocked); /* Mask all signals */ | |
239 | recalc_sigpending(); | |
240 | spin_unlock_irqrestore(¤t->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(¤t->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(¤t->sighand->siglock, flags); | |
274 | current->blocked = oldset; | |
275 | recalc_sigpending(); | |
276 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
277 | ||
278 | done: | |
279 | dprintk("lockd: clnt proc returns %d\n", status); | |
280 | nlm_release_host(host); | |
281 | return status; | |
282 | } | |
283 | EXPORT_SYMBOL(nlmclnt_proc); | |
284 | ||
285 | /* | |
286 | * Allocate an NLM RPC call struct | |
287 | */ | |
288 | struct nlm_rqst * | |
289 | nlmclnt_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"); | |
041e0e3b | 302 | schedule_timeout_interruptible(5*HZ); |
1da177e4 LT |
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); | |
3e1d1d28 | 315 | try_to_freeze(); |
1da177e4 LT |
316 | if (!signalled ()) |
317 | status = 0; | |
318 | } | |
319 | finish_wait(queue, &wait); | |
320 | return status; | |
321 | } | |
322 | ||
323 | /* | |
324 | * Generic NLM call | |
325 | */ | |
326 | static int | |
327 | nlmclnt_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 | ||
387 | in_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 | */ | |
403 | int | |
404 | nlmsvc_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 | ||
428 | static int | |
429 | nlmclnt_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 | */ | |
461 | static int | |
462 | nlmclnt_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 | ||
487 | static 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 | ||
493 | static 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 | ||
499 | static 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 | ||
504 | static 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 | ||
513 | static 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 | */ | |
551 | static int | |
552 | nlmclnt_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; | |
ecdbf769 TM |
556 | long timeout; |
557 | int status; | |
1da177e4 LT |
558 | |
559 | if (!host->h_monitored && nsm_monitor(host) < 0) { | |
560 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", | |
561 | host->h_name); | |
562 | status = -ENOLCK; | |
563 | goto out; | |
564 | } | |
565 | ||
ecdbf769 TM |
566 | if (req->a_args.block) { |
567 | status = nlmclnt_prepare_block(req, host, fl); | |
1da177e4 LT |
568 | if (status < 0) |
569 | goto out; | |
ecdbf769 TM |
570 | } |
571 | for(;;) { | |
572 | status = nlmclnt_call(req, NLMPROC_LOCK); | |
573 | if (status < 0) | |
574 | goto out_unblock; | |
575 | if (resp->status != NLM_LCK_BLOCKED) | |
576 | break; | |
577 | /* Wait on an NLM blocking lock */ | |
578 | timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT); | |
579 | /* Did a reclaimer thread notify us of a server reboot? */ | |
580 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) | |
581 | continue; | |
582 | if (resp->status != NLM_LCK_BLOCKED) | |
583 | break; | |
584 | if (timeout >= 0) | |
585 | continue; | |
586 | /* We were interrupted. Send a CANCEL request to the server | |
587 | * and exit | |
588 | */ | |
589 | status = (int)timeout; | |
590 | goto out_unblock; | |
591 | } | |
1da177e4 LT |
592 | |
593 | if (resp->status == NLM_LCK_GRANTED) { | |
594 | fl->fl_u.nfs_fl.state = host->h_state; | |
595 | fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED; | |
596 | fl->fl_flags |= FL_SLEEP; | |
597 | do_vfs_lock(fl); | |
598 | } | |
599 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 TM |
600 | out_unblock: |
601 | nlmclnt_finish_block(req); | |
602 | /* Cancel the blocked request if it is still pending */ | |
603 | if (resp->status == NLM_LCK_BLOCKED) | |
604 | nlmclnt_cancel(host, fl); | |
1da177e4 LT |
605 | out: |
606 | nlmclnt_release_lockargs(req); | |
607 | return status; | |
608 | } | |
609 | ||
610 | /* | |
611 | * RECLAIM: Try to reclaim a lock | |
612 | */ | |
613 | int | |
614 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
615 | { | |
616 | struct nlm_rqst reqst, *req; | |
617 | int status; | |
618 | ||
619 | req = &reqst; | |
620 | memset(req, 0, sizeof(*req)); | |
621 | locks_init_lock(&req->a_args.lock.fl); | |
622 | locks_init_lock(&req->a_res.lock.fl); | |
623 | req->a_host = host; | |
624 | req->a_flags = 0; | |
625 | ||
626 | /* Set up the argument struct */ | |
627 | nlmclnt_setlockargs(req, fl); | |
628 | req->a_args.reclaim = 1; | |
629 | ||
630 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
631 | && req->a_res.status == NLM_LCK_GRANTED) | |
632 | return 0; | |
633 | ||
634 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
635 | "(errno %d, status %d)\n", fl->fl_pid, | |
636 | status, req->a_res.status); | |
637 | ||
638 | /* | |
639 | * FIXME: This is a serious failure. We can | |
640 | * | |
641 | * a. Ignore the problem | |
642 | * b. Send the owning process some signal (Linux doesn't have | |
643 | * SIGLOST, though...) | |
644 | * c. Retry the operation | |
645 | * | |
646 | * Until someone comes up with a simple implementation | |
647 | * for b or c, I'll choose option a. | |
648 | */ | |
649 | ||
650 | return -ENOLCK; | |
651 | } | |
652 | ||
653 | /* | |
654 | * UNLOCK: remove an existing lock | |
655 | */ | |
656 | static int | |
657 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
658 | { | |
659 | struct nlm_res *resp = &req->a_res; | |
660 | int status; | |
661 | ||
662 | /* Clean the GRANTED flag now so the lock doesn't get | |
663 | * reclaimed while we're stuck in the unlock call. */ | |
664 | fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED; | |
665 | ||
666 | if (req->a_flags & RPC_TASK_ASYNC) { | |
667 | status = nlmclnt_async_call(req, NLMPROC_UNLOCK, | |
668 | nlmclnt_unlock_callback); | |
669 | /* Hrmf... Do the unlock early since locks_remove_posix() | |
670 | * really expects us to free the lock synchronously */ | |
671 | do_vfs_lock(fl); | |
672 | if (status < 0) { | |
673 | nlmclnt_release_lockargs(req); | |
674 | kfree(req); | |
675 | } | |
676 | return status; | |
677 | } | |
678 | ||
679 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
680 | nlmclnt_release_lockargs(req); | |
681 | if (status < 0) | |
682 | return status; | |
683 | ||
684 | do_vfs_lock(fl); | |
685 | if (resp->status == NLM_LCK_GRANTED) | |
686 | return 0; | |
687 | ||
688 | if (resp->status != NLM_LCK_DENIED_NOLOCKS) | |
689 | printk("lockd: unexpected unlock status: %d\n", resp->status); | |
690 | ||
691 | /* What to do now? I'm out of my depth... */ | |
692 | ||
693 | return -ENOLCK; | |
694 | } | |
695 | ||
696 | static void | |
697 | nlmclnt_unlock_callback(struct rpc_task *task) | |
698 | { | |
699 | struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata; | |
700 | int status = req->a_res.status; | |
701 | ||
702 | if (RPC_ASSASSINATED(task)) | |
703 | goto die; | |
704 | ||
705 | if (task->tk_status < 0) { | |
706 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
707 | goto retry_rebind; | |
708 | } | |
709 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
710 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
711 | goto retry_unlock; | |
712 | } | |
713 | if (status != NLM_LCK_GRANTED) | |
714 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
715 | die: | |
716 | nlm_release_host(req->a_host); | |
717 | nlmclnt_release_lockargs(req); | |
718 | kfree(req); | |
719 | return; | |
720 | retry_rebind: | |
721 | nlm_rebind_host(req->a_host); | |
722 | retry_unlock: | |
723 | rpc_restart_call(task); | |
724 | } | |
725 | ||
726 | /* | |
727 | * Cancel a blocked lock request. | |
728 | * We always use an async RPC call for this in order not to hang a | |
729 | * process that has been Ctrl-C'ed. | |
730 | */ | |
731 | int | |
732 | nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl) | |
733 | { | |
734 | struct nlm_rqst *req; | |
735 | unsigned long flags; | |
736 | sigset_t oldset; | |
737 | int status; | |
738 | ||
739 | /* Block all signals while setting up call */ | |
740 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
741 | oldset = current->blocked; | |
742 | sigfillset(¤t->blocked); | |
743 | recalc_sigpending(); | |
744 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
745 | ||
746 | req = nlmclnt_alloc_call(); | |
747 | if (!req) | |
748 | return -ENOMEM; | |
749 | req->a_host = host; | |
750 | req->a_flags = RPC_TASK_ASYNC; | |
751 | ||
752 | nlmclnt_setlockargs(req, fl); | |
753 | ||
754 | status = nlmclnt_async_call(req, NLMPROC_CANCEL, | |
755 | nlmclnt_cancel_callback); | |
756 | if (status < 0) { | |
757 | nlmclnt_release_lockargs(req); | |
758 | kfree(req); | |
759 | } | |
760 | ||
761 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
762 | current->blocked = oldset; | |
763 | recalc_sigpending(); | |
764 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
765 | ||
766 | return status; | |
767 | } | |
768 | ||
769 | static void | |
770 | nlmclnt_cancel_callback(struct rpc_task *task) | |
771 | { | |
772 | struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata; | |
773 | ||
774 | if (RPC_ASSASSINATED(task)) | |
775 | goto die; | |
776 | ||
777 | if (task->tk_status < 0) { | |
778 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
779 | task->tk_status); | |
780 | goto retry_cancel; | |
781 | } | |
782 | ||
783 | dprintk("lockd: cancel status %d (task %d)\n", | |
784 | req->a_res.status, task->tk_pid); | |
785 | ||
786 | switch (req->a_res.status) { | |
787 | case NLM_LCK_GRANTED: | |
788 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
789 | /* Everything's good */ | |
790 | break; | |
791 | case NLM_LCK_DENIED_NOLOCKS: | |
792 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
793 | goto retry_cancel; | |
794 | default: | |
795 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
796 | req->a_res.status); | |
797 | } | |
798 | ||
799 | die: | |
800 | nlm_release_host(req->a_host); | |
801 | nlmclnt_release_lockargs(req); | |
802 | kfree(req); | |
803 | return; | |
804 | ||
805 | retry_cancel: | |
806 | nlm_rebind_host(req->a_host); | |
807 | rpc_restart_call(task); | |
808 | rpc_delay(task, 30 * HZ); | |
809 | } | |
810 | ||
811 | /* | |
812 | * Convert an NLM status code to a generic kernel errno | |
813 | */ | |
814 | static int | |
815 | nlm_stat_to_errno(u32 status) | |
816 | { | |
817 | switch(status) { | |
818 | case NLM_LCK_GRANTED: | |
819 | return 0; | |
820 | case NLM_LCK_DENIED: | |
821 | return -EAGAIN; | |
822 | case NLM_LCK_DENIED_NOLOCKS: | |
823 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
824 | return -ENOLCK; | |
825 | case NLM_LCK_BLOCKED: | |
826 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
827 | return -ENOLCK; | |
828 | #ifdef CONFIG_LOCKD_V4 | |
829 | case NLM_DEADLCK: | |
830 | return -EDEADLK; | |
831 | case NLM_ROFS: | |
832 | return -EROFS; | |
833 | case NLM_STALE_FH: | |
834 | return -ESTALE; | |
835 | case NLM_FBIG: | |
836 | return -EOVERFLOW; | |
837 | case NLM_FAILED: | |
838 | return -ENOLCK; | |
839 | #endif | |
840 | } | |
841 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
842 | return -ENOLCK; | |
843 | } |