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); | |
f99d49ad | 115 | kfree(new); |
1da177e4 LT |
116 | return res; |
117 | } | |
118 | ||
119 | /* | |
120 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
121 | */ | |
122 | static 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 | ||
137 | static 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 | */ | |
149 | int | |
150 | nlmclnt_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 | ||
173 | void | |
174 | nlmclnt_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 | */ | |
190 | int | |
191 | nlmclnt_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(¤t->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(¤t->blocked); /* Mask all signals */ | |
238 | recalc_sigpending(); | |
239 | spin_unlock_irqrestore(¤t->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(¤t->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(¤t->sighand->siglock, flags); | |
273 | current->blocked = oldset; | |
274 | recalc_sigpending(); | |
275 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
276 | ||
277 | done: | |
278 | dprintk("lockd: clnt proc returns %d\n", status); | |
279 | nlm_release_host(host); | |
280 | return status; | |
281 | } | |
282 | EXPORT_SYMBOL(nlmclnt_proc); | |
283 | ||
284 | /* | |
285 | * Allocate an NLM RPC call struct | |
286 | */ | |
287 | struct nlm_rqst * | |
288 | nlmclnt_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"); | |
041e0e3b | 301 | schedule_timeout_interruptible(5*HZ); |
1da177e4 LT |
302 | } |
303 | return NULL; | |
304 | } | |
305 | ||
306 | static int nlm_wait_on_grace(wait_queue_head_t *queue) | |
307 | { | |
308 | DEFINE_WAIT(wait); | |
309 | int status = -EINTR; | |
310 | ||
311 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
312 | if (!signalled ()) { | |
313 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 314 | try_to_freeze(); |
1da177e4 LT |
315 | if (!signalled ()) |
316 | status = 0; | |
317 | } | |
318 | finish_wait(queue, &wait); | |
319 | return status; | |
320 | } | |
321 | ||
322 | /* | |
323 | * Generic NLM call | |
324 | */ | |
325 | static int | |
326 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
327 | { | |
328 | struct nlm_host *host = req->a_host; | |
329 | struct rpc_clnt *clnt; | |
330 | struct nlm_args *argp = &req->a_args; | |
331 | struct nlm_res *resp = &req->a_res; | |
332 | struct rpc_message msg = { | |
333 | .rpc_argp = argp, | |
334 | .rpc_resp = resp, | |
335 | }; | |
336 | int status; | |
337 | ||
338 | dprintk("lockd: call procedure %d on %s\n", | |
339 | (int)proc, host->h_name); | |
340 | ||
341 | do { | |
342 | if (host->h_reclaiming && !argp->reclaim) | |
343 | goto in_grace_period; | |
344 | ||
345 | /* If we have no RPC client yet, create one. */ | |
346 | if ((clnt = nlm_bind_host(host)) == NULL) | |
347 | return -ENOLCK; | |
348 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
349 | ||
350 | /* Perform the RPC call. If an error occurs, try again */ | |
351 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
352 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
353 | switch (status) { | |
354 | case -EPROTONOSUPPORT: | |
355 | status = -EINVAL; | |
356 | break; | |
357 | case -ECONNREFUSED: | |
358 | case -ETIMEDOUT: | |
359 | case -ENOTCONN: | |
360 | nlm_rebind_host(host); | |
361 | status = -EAGAIN; | |
362 | break; | |
363 | case -ERESTARTSYS: | |
364 | return signalled () ? -EINTR : status; | |
365 | default: | |
366 | break; | |
367 | } | |
368 | break; | |
369 | } else | |
370 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
371 | dprintk("lockd: server in grace period\n"); | |
372 | if (argp->reclaim) { | |
373 | printk(KERN_WARNING | |
374 | "lockd: spurious grace period reject?!\n"); | |
375 | return -ENOLCK; | |
376 | } | |
377 | } else { | |
378 | if (!argp->reclaim) { | |
379 | /* We appear to be out of the grace period */ | |
380 | wake_up_all(&host->h_gracewait); | |
381 | } | |
382 | dprintk("lockd: server returns status %d\n", resp->status); | |
383 | return 0; /* Okay, call complete */ | |
384 | } | |
385 | ||
386 | in_grace_period: | |
387 | /* | |
388 | * The server has rebooted and appears to be in the grace | |
389 | * period during which locks are only allowed to be | |
390 | * reclaimed. | |
391 | * We can only back off and try again later. | |
392 | */ | |
393 | status = nlm_wait_on_grace(&host->h_gracewait); | |
394 | } while (status == 0); | |
395 | ||
396 | return status; | |
397 | } | |
398 | ||
399 | /* | |
400 | * Generic NLM call, async version. | |
401 | */ | |
402 | int | |
403 | nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback) | |
404 | { | |
405 | struct nlm_host *host = req->a_host; | |
406 | struct rpc_clnt *clnt; | |
407 | struct rpc_message msg = { | |
408 | .rpc_argp = &req->a_args, | |
409 | .rpc_resp = &req->a_res, | |
410 | }; | |
411 | int status; | |
412 | ||
413 | dprintk("lockd: call procedure %d on %s (async)\n", | |
414 | (int)proc, host->h_name); | |
415 | ||
416 | /* If we have no RPC client yet, create one. */ | |
417 | if ((clnt = nlm_bind_host(host)) == NULL) | |
418 | return -ENOLCK; | |
419 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
420 | ||
421 | /* bootstrap and kick off the async RPC call */ | |
422 | status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req); | |
423 | ||
424 | return status; | |
425 | } | |
426 | ||
427 | static int | |
428 | nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback) | |
429 | { | |
430 | struct nlm_host *host = req->a_host; | |
431 | struct rpc_clnt *clnt; | |
432 | struct nlm_args *argp = &req->a_args; | |
433 | struct nlm_res *resp = &req->a_res; | |
434 | struct rpc_message msg = { | |
435 | .rpc_argp = argp, | |
436 | .rpc_resp = resp, | |
437 | }; | |
438 | int status; | |
439 | ||
440 | dprintk("lockd: call procedure %d on %s (async)\n", | |
441 | (int)proc, host->h_name); | |
442 | ||
443 | /* If we have no RPC client yet, create one. */ | |
444 | if ((clnt = nlm_bind_host(host)) == NULL) | |
445 | return -ENOLCK; | |
446 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
447 | ||
448 | /* Increment host refcount */ | |
449 | nlm_get_host(host); | |
450 | /* bootstrap and kick off the async RPC call */ | |
451 | status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req); | |
452 | if (status < 0) | |
453 | nlm_release_host(host); | |
454 | return status; | |
455 | } | |
456 | ||
457 | /* | |
458 | * TEST for the presence of a conflicting lock | |
459 | */ | |
460 | static int | |
461 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
462 | { | |
463 | int status; | |
464 | ||
465 | status = nlmclnt_call(req, NLMPROC_TEST); | |
466 | nlmclnt_release_lockargs(req); | |
467 | if (status < 0) | |
468 | return status; | |
469 | ||
470 | status = req->a_res.status; | |
471 | if (status == NLM_LCK_GRANTED) { | |
472 | fl->fl_type = F_UNLCK; | |
473 | } if (status == NLM_LCK_DENIED) { | |
474 | /* | |
475 | * Report the conflicting lock back to the application. | |
476 | */ | |
477 | locks_copy_lock(fl, &req->a_res.lock.fl); | |
478 | fl->fl_pid = 0; | |
479 | } else { | |
480 | return nlm_stat_to_errno(req->a_res.status); | |
481 | } | |
482 | ||
483 | return 0; | |
484 | } | |
485 | ||
486 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
487 | { | |
488 | memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl)); | |
489 | nlm_get_lockowner(new->fl_u.nfs_fl.owner); | |
490 | } | |
491 | ||
492 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
493 | { | |
494 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); | |
495 | fl->fl_ops = NULL; | |
496 | } | |
497 | ||
498 | static struct file_lock_operations nlmclnt_lock_ops = { | |
499 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
500 | .fl_release_private = nlmclnt_locks_release_private, | |
501 | }; | |
502 | ||
503 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
504 | { | |
505 | BUG_ON(fl->fl_ops != NULL); | |
506 | fl->fl_u.nfs_fl.state = 0; | |
507 | fl->fl_u.nfs_fl.flags = 0; | |
508 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); | |
509 | fl->fl_ops = &nlmclnt_lock_ops; | |
510 | } | |
511 | ||
512 | static void do_vfs_lock(struct file_lock *fl) | |
513 | { | |
514 | int res = 0; | |
515 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
516 | case FL_POSIX: | |
517 | res = posix_lock_file_wait(fl->fl_file, fl); | |
518 | break; | |
519 | case FL_FLOCK: | |
520 | res = flock_lock_file_wait(fl->fl_file, fl); | |
521 | break; | |
522 | default: | |
523 | BUG(); | |
524 | } | |
525 | if (res < 0) | |
526 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", | |
527 | __FUNCTION__); | |
528 | } | |
529 | ||
530 | /* | |
531 | * LOCK: Try to create a lock | |
532 | * | |
533 | * Programmer Harassment Alert | |
534 | * | |
535 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
536 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
537 | * the lock could be granted. This way, our local process could hang | |
538 | * around forever waiting for the callback. | |
539 | * | |
540 | * Solution A: Implement busy-waiting | |
541 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
542 | * | |
543 | * For now I am implementing solution A, because I hate the idea of | |
544 | * re-implementing lockd for a third time in two months. The async | |
545 | * calls shouldn't be too hard to do, however. | |
546 | * | |
547 | * This is one of the lovely things about standards in the NFS area: | |
548 | * they're so soft and squishy you can't really blame HP for doing this. | |
549 | */ | |
550 | static int | |
551 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
552 | { | |
553 | struct nlm_host *host = req->a_host; | |
554 | struct nlm_res *resp = &req->a_res; | |
ecdbf769 TM |
555 | long timeout; |
556 | int status; | |
1da177e4 LT |
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 | ||
ecdbf769 TM |
565 | if (req->a_args.block) { |
566 | status = nlmclnt_prepare_block(req, host, fl); | |
1da177e4 LT |
567 | if (status < 0) |
568 | goto out; | |
ecdbf769 TM |
569 | } |
570 | for(;;) { | |
571 | status = nlmclnt_call(req, NLMPROC_LOCK); | |
572 | if (status < 0) | |
573 | goto out_unblock; | |
574 | if (resp->status != NLM_LCK_BLOCKED) | |
575 | break; | |
576 | /* Wait on an NLM blocking lock */ | |
577 | timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT); | |
578 | /* Did a reclaimer thread notify us of a server reboot? */ | |
579 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) | |
580 | continue; | |
581 | if (resp->status != NLM_LCK_BLOCKED) | |
582 | break; | |
583 | if (timeout >= 0) | |
584 | continue; | |
585 | /* We were interrupted. Send a CANCEL request to the server | |
586 | * and exit | |
587 | */ | |
588 | status = (int)timeout; | |
589 | goto out_unblock; | |
590 | } | |
1da177e4 LT |
591 | |
592 | if (resp->status == NLM_LCK_GRANTED) { | |
593 | fl->fl_u.nfs_fl.state = host->h_state; | |
594 | fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED; | |
595 | fl->fl_flags |= FL_SLEEP; | |
596 | do_vfs_lock(fl); | |
597 | } | |
598 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 TM |
599 | out_unblock: |
600 | nlmclnt_finish_block(req); | |
601 | /* Cancel the blocked request if it is still pending */ | |
602 | if (resp->status == NLM_LCK_BLOCKED) | |
603 | nlmclnt_cancel(host, fl); | |
1da177e4 LT |
604 | out: |
605 | nlmclnt_release_lockargs(req); | |
606 | return status; | |
607 | } | |
608 | ||
609 | /* | |
610 | * RECLAIM: Try to reclaim a lock | |
611 | */ | |
612 | int | |
613 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
614 | { | |
615 | struct nlm_rqst reqst, *req; | |
616 | int status; | |
617 | ||
618 | req = &reqst; | |
619 | memset(req, 0, sizeof(*req)); | |
620 | locks_init_lock(&req->a_args.lock.fl); | |
621 | locks_init_lock(&req->a_res.lock.fl); | |
622 | req->a_host = host; | |
623 | req->a_flags = 0; | |
624 | ||
625 | /* Set up the argument struct */ | |
626 | nlmclnt_setlockargs(req, fl); | |
627 | req->a_args.reclaim = 1; | |
628 | ||
629 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
630 | && req->a_res.status == NLM_LCK_GRANTED) | |
631 | return 0; | |
632 | ||
633 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
634 | "(errno %d, status %d)\n", fl->fl_pid, | |
635 | status, req->a_res.status); | |
636 | ||
637 | /* | |
638 | * FIXME: This is a serious failure. We can | |
639 | * | |
640 | * a. Ignore the problem | |
641 | * b. Send the owning process some signal (Linux doesn't have | |
642 | * SIGLOST, though...) | |
643 | * c. Retry the operation | |
644 | * | |
645 | * Until someone comes up with a simple implementation | |
646 | * for b or c, I'll choose option a. | |
647 | */ | |
648 | ||
649 | return -ENOLCK; | |
650 | } | |
651 | ||
652 | /* | |
653 | * UNLOCK: remove an existing lock | |
654 | */ | |
655 | static int | |
656 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
657 | { | |
658 | struct nlm_res *resp = &req->a_res; | |
659 | int status; | |
660 | ||
661 | /* Clean the GRANTED flag now so the lock doesn't get | |
662 | * reclaimed while we're stuck in the unlock call. */ | |
663 | fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED; | |
664 | ||
665 | if (req->a_flags & RPC_TASK_ASYNC) { | |
666 | status = nlmclnt_async_call(req, NLMPROC_UNLOCK, | |
667 | nlmclnt_unlock_callback); | |
668 | /* Hrmf... Do the unlock early since locks_remove_posix() | |
669 | * really expects us to free the lock synchronously */ | |
670 | do_vfs_lock(fl); | |
671 | if (status < 0) { | |
672 | nlmclnt_release_lockargs(req); | |
673 | kfree(req); | |
674 | } | |
675 | return status; | |
676 | } | |
677 | ||
678 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
679 | nlmclnt_release_lockargs(req); | |
680 | if (status < 0) | |
681 | return status; | |
682 | ||
683 | do_vfs_lock(fl); | |
684 | if (resp->status == NLM_LCK_GRANTED) | |
685 | return 0; | |
686 | ||
687 | if (resp->status != NLM_LCK_DENIED_NOLOCKS) | |
688 | printk("lockd: unexpected unlock status: %d\n", resp->status); | |
689 | ||
690 | /* What to do now? I'm out of my depth... */ | |
691 | ||
692 | return -ENOLCK; | |
693 | } | |
694 | ||
695 | static void | |
696 | nlmclnt_unlock_callback(struct rpc_task *task) | |
697 | { | |
698 | struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata; | |
699 | int status = req->a_res.status; | |
700 | ||
701 | if (RPC_ASSASSINATED(task)) | |
702 | goto die; | |
703 | ||
704 | if (task->tk_status < 0) { | |
705 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
706 | goto retry_rebind; | |
707 | } | |
708 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
709 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
710 | goto retry_unlock; | |
711 | } | |
712 | if (status != NLM_LCK_GRANTED) | |
713 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
714 | die: | |
715 | nlm_release_host(req->a_host); | |
716 | nlmclnt_release_lockargs(req); | |
717 | kfree(req); | |
718 | return; | |
719 | retry_rebind: | |
720 | nlm_rebind_host(req->a_host); | |
721 | retry_unlock: | |
722 | rpc_restart_call(task); | |
723 | } | |
724 | ||
725 | /* | |
726 | * Cancel a blocked lock request. | |
727 | * We always use an async RPC call for this in order not to hang a | |
728 | * process that has been Ctrl-C'ed. | |
729 | */ | |
730 | int | |
731 | nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl) | |
732 | { | |
733 | struct nlm_rqst *req; | |
734 | unsigned long flags; | |
735 | sigset_t oldset; | |
736 | int status; | |
737 | ||
738 | /* Block all signals while setting up call */ | |
739 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
740 | oldset = current->blocked; | |
741 | sigfillset(¤t->blocked); | |
742 | recalc_sigpending(); | |
743 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
744 | ||
745 | req = nlmclnt_alloc_call(); | |
746 | if (!req) | |
747 | return -ENOMEM; | |
748 | req->a_host = host; | |
749 | req->a_flags = RPC_TASK_ASYNC; | |
750 | ||
751 | nlmclnt_setlockargs(req, fl); | |
752 | ||
753 | status = nlmclnt_async_call(req, NLMPROC_CANCEL, | |
754 | nlmclnt_cancel_callback); | |
755 | if (status < 0) { | |
756 | nlmclnt_release_lockargs(req); | |
757 | kfree(req); | |
758 | } | |
759 | ||
760 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
761 | current->blocked = oldset; | |
762 | recalc_sigpending(); | |
763 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
764 | ||
765 | return status; | |
766 | } | |
767 | ||
768 | static void | |
769 | nlmclnt_cancel_callback(struct rpc_task *task) | |
770 | { | |
771 | struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata; | |
772 | ||
773 | if (RPC_ASSASSINATED(task)) | |
774 | goto die; | |
775 | ||
776 | if (task->tk_status < 0) { | |
777 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
778 | task->tk_status); | |
779 | goto retry_cancel; | |
780 | } | |
781 | ||
782 | dprintk("lockd: cancel status %d (task %d)\n", | |
783 | req->a_res.status, task->tk_pid); | |
784 | ||
785 | switch (req->a_res.status) { | |
786 | case NLM_LCK_GRANTED: | |
787 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
788 | /* Everything's good */ | |
789 | break; | |
790 | case NLM_LCK_DENIED_NOLOCKS: | |
791 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
792 | goto retry_cancel; | |
793 | default: | |
794 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
795 | req->a_res.status); | |
796 | } | |
797 | ||
798 | die: | |
799 | nlm_release_host(req->a_host); | |
800 | nlmclnt_release_lockargs(req); | |
801 | kfree(req); | |
802 | return; | |
803 | ||
804 | retry_cancel: | |
805 | nlm_rebind_host(req->a_host); | |
806 | rpc_restart_call(task); | |
807 | rpc_delay(task, 30 * HZ); | |
808 | } | |
809 | ||
810 | /* | |
811 | * Convert an NLM status code to a generic kernel errno | |
812 | */ | |
813 | static int | |
814 | nlm_stat_to_errno(u32 status) | |
815 | { | |
816 | switch(status) { | |
817 | case NLM_LCK_GRANTED: | |
818 | return 0; | |
819 | case NLM_LCK_DENIED: | |
820 | return -EAGAIN; | |
821 | case NLM_LCK_DENIED_NOLOCKS: | |
822 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
823 | return -ENOLCK; | |
824 | case NLM_LCK_BLOCKED: | |
825 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
826 | return -ENOLCK; | |
827 | #ifdef CONFIG_LOCKD_V4 | |
828 | case NLM_DEADLCK: | |
829 | return -EDEADLK; | |
830 | case NLM_ROFS: | |
831 | return -EROFS; | |
832 | case NLM_STALE_FH: | |
833 | return -ESTALE; | |
834 | case NLM_FBIG: | |
835 | return -EOVERFLOW; | |
836 | case NLM_FAILED: | |
837 | return -ENOLCK; | |
838 | #endif | |
839 | } | |
840 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
841 | return -ENOLCK; | |
842 | } |