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) |
aaaa9942 | 25 | #define NLMCLNT_MAX_RETRIES 3 |
1da177e4 LT |
26 | |
27 | static int nlmclnt_test(struct nlm_rqst *, struct file_lock *); | |
28 | static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *); | |
29 | static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *); | |
1da177e4 LT |
30 | static int nlm_stat_to_errno(u32 stat); |
31 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); | |
16fb2425 | 32 | static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
1da177e4 | 33 | |
963d8fe5 TM |
34 | static const struct rpc_call_ops nlmclnt_unlock_ops; |
35 | static const struct rpc_call_ops nlmclnt_cancel_ops; | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * Cookie counter for NLM requests | |
39 | */ | |
40 | static u32 nlm_cookie = 0x1234; | |
41 | ||
42 | static inline void nlmclnt_next_cookie(struct nlm_cookie *c) | |
43 | { | |
44 | memcpy(c->data, &nlm_cookie, 4); | |
45 | memset(c->data+4, 0, 4); | |
46 | c->len=4; | |
47 | nlm_cookie++; | |
48 | } | |
49 | ||
50 | static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner) | |
51 | { | |
52 | atomic_inc(&lockowner->count); | |
53 | return lockowner; | |
54 | } | |
55 | ||
56 | static void nlm_put_lockowner(struct nlm_lockowner *lockowner) | |
57 | { | |
58 | if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) | |
59 | return; | |
60 | list_del(&lockowner->list); | |
61 | spin_unlock(&lockowner->host->h_lock); | |
62 | nlm_release_host(lockowner->host); | |
63 | kfree(lockowner); | |
64 | } | |
65 | ||
66 | static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) | |
67 | { | |
68 | struct nlm_lockowner *lockowner; | |
69 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
70 | if (lockowner->pid == pid) | |
71 | return -EBUSY; | |
72 | } | |
73 | return 0; | |
74 | } | |
75 | ||
76 | static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) | |
77 | { | |
78 | uint32_t res; | |
79 | do { | |
80 | res = host->h_pidcount++; | |
81 | } while (nlm_pidbusy(host, res) < 0); | |
82 | return res; | |
83 | } | |
84 | ||
85 | static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
86 | { | |
87 | struct nlm_lockowner *lockowner; | |
88 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
89 | if (lockowner->owner != owner) | |
90 | continue; | |
91 | return nlm_get_lockowner(lockowner); | |
92 | } | |
93 | return NULL; | |
94 | } | |
95 | ||
96 | static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
97 | { | |
98 | struct nlm_lockowner *res, *new = NULL; | |
99 | ||
100 | spin_lock(&host->h_lock); | |
101 | res = __nlm_find_lockowner(host, owner); | |
102 | if (res == NULL) { | |
103 | spin_unlock(&host->h_lock); | |
104 | new = (struct nlm_lockowner *)kmalloc(sizeof(*new), GFP_KERNEL); | |
105 | spin_lock(&host->h_lock); | |
106 | res = __nlm_find_lockowner(host, owner); | |
107 | if (res == NULL && new != NULL) { | |
108 | res = new; | |
109 | atomic_set(&new->count, 1); | |
110 | new->owner = owner; | |
111 | new->pid = __nlm_alloc_pid(host); | |
112 | new->host = nlm_get_host(host); | |
113 | list_add(&new->list, &host->h_lockowners); | |
114 | new = NULL; | |
115 | } | |
116 | } | |
117 | spin_unlock(&host->h_lock); | |
f99d49ad | 118 | kfree(new); |
1da177e4 LT |
119 | return res; |
120 | } | |
121 | ||
122 | /* | |
123 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
124 | */ | |
125 | static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) | |
126 | { | |
127 | struct nlm_args *argp = &req->a_args; | |
128 | struct nlm_lock *lock = &argp->lock; | |
129 | ||
130 | nlmclnt_next_cookie(&argp->cookie); | |
131 | argp->state = nsm_local_state; | |
132 | memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh)); | |
133 | lock->caller = system_utsname.nodename; | |
134 | lock->oh.data = req->a_owner; | |
7bab377f TM |
135 | lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
136 | (unsigned int)fl->fl_u.nfs_fl.owner->pid, | |
137 | system_utsname.nodename); | |
138 | lock->svid = fl->fl_u.nfs_fl.owner->pid; | |
3a649b88 TM |
139 | lock->fl.fl_start = fl->fl_start; |
140 | lock->fl.fl_end = fl->fl_end; | |
141 | lock->fl.fl_type = fl->fl_type; | |
1da177e4 LT |
142 | } |
143 | ||
144 | static void nlmclnt_release_lockargs(struct nlm_rqst *req) | |
145 | { | |
3a649b88 | 146 | BUG_ON(req->a_args.lock.fl.fl_ops != NULL); |
1da177e4 LT |
147 | } |
148 | ||
1da177e4 LT |
149 | /* |
150 | * This is the main entry point for the NLM client. | |
151 | */ | |
152 | int | |
153 | nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl) | |
154 | { | |
155 | struct nfs_server *nfssrv = NFS_SERVER(inode); | |
156 | struct nlm_host *host; | |
157 | struct nlm_rqst reqst, *call = &reqst; | |
158 | sigset_t oldset; | |
159 | unsigned long flags; | |
160 | int status, proto, vers; | |
161 | ||
162 | vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1; | |
163 | if (NFS_PROTO(inode)->version > 3) { | |
164 | printk(KERN_NOTICE "NFSv4 file locking not implemented!\n"); | |
165 | return -ENOLCK; | |
166 | } | |
167 | ||
168 | /* Retrieve transport protocol from NFS client */ | |
169 | proto = NFS_CLIENT(inode)->cl_xprt->prot; | |
170 | ||
171 | if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers))) | |
172 | return -ENOLCK; | |
173 | ||
174 | /* Create RPC client handle if not there, and copy soft | |
175 | * and intr flags from NFS client. */ | |
176 | if (host->h_rpcclnt == NULL) { | |
177 | struct rpc_clnt *clnt; | |
178 | ||
179 | /* Bind an rpc client to this host handle (does not | |
180 | * perform a portmapper lookup) */ | |
181 | if (!(clnt = nlm_bind_host(host))) { | |
182 | status = -ENOLCK; | |
183 | goto done; | |
184 | } | |
185 | clnt->cl_softrtry = nfssrv->client->cl_softrtry; | |
f518e35a | 186 | clnt->cl_intr = nfssrv->client->cl_intr; |
1da177e4 LT |
187 | } |
188 | ||
189 | /* Keep the old signal mask */ | |
190 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
191 | oldset = current->blocked; | |
192 | ||
193 | /* If we're cleaning up locks because the process is exiting, | |
194 | * perform the RPC call asynchronously. */ | |
195 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) | |
196 | && fl->fl_type == F_UNLCK | |
197 | && (current->flags & PF_EXITING)) { | |
198 | sigfillset(¤t->blocked); /* Mask all signals */ | |
199 | recalc_sigpending(); | |
200 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
201 | ||
202 | call = nlmclnt_alloc_call(); | |
203 | if (!call) { | |
204 | status = -ENOMEM; | |
205 | goto out_restore; | |
206 | } | |
207 | call->a_flags = RPC_TASK_ASYNC; | |
208 | } else { | |
209 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
210 | memset(call, 0, sizeof(*call)); | |
211 | locks_init_lock(&call->a_args.lock.fl); | |
212 | locks_init_lock(&call->a_res.lock.fl); | |
213 | } | |
214 | call->a_host = host; | |
215 | ||
216 | nlmclnt_locks_init_private(fl, host); | |
217 | ||
218 | /* Set up the argument struct */ | |
219 | nlmclnt_setlockargs(call, fl); | |
220 | ||
221 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { | |
222 | if (fl->fl_type != F_UNLCK) { | |
223 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
224 | status = nlmclnt_lock(call, fl); | |
225 | } else | |
226 | status = nlmclnt_unlock(call, fl); | |
227 | } else if (IS_GETLK(cmd)) | |
228 | status = nlmclnt_test(call, fl); | |
229 | else | |
230 | status = -EINVAL; | |
231 | ||
232 | out_restore: | |
233 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
234 | current->blocked = oldset; | |
235 | recalc_sigpending(); | |
236 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
237 | ||
238 | done: | |
239 | dprintk("lockd: clnt proc returns %d\n", status); | |
240 | nlm_release_host(host); | |
241 | return status; | |
242 | } | |
243 | EXPORT_SYMBOL(nlmclnt_proc); | |
244 | ||
245 | /* | |
246 | * Allocate an NLM RPC call struct | |
247 | */ | |
248 | struct nlm_rqst * | |
249 | nlmclnt_alloc_call(void) | |
250 | { | |
251 | struct nlm_rqst *call; | |
252 | ||
36943fa4 TM |
253 | for(;;) { |
254 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
255 | if (call != NULL) { | |
1da177e4 LT |
256 | locks_init_lock(&call->a_args.lock.fl); |
257 | locks_init_lock(&call->a_res.lock.fl); | |
258 | return call; | |
259 | } | |
36943fa4 TM |
260 | if (signalled()) |
261 | break; | |
1da177e4 | 262 | printk("nlmclnt_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 263 | schedule_timeout_interruptible(5*HZ); |
1da177e4 LT |
264 | } |
265 | return NULL; | |
266 | } | |
267 | ||
268 | static int nlm_wait_on_grace(wait_queue_head_t *queue) | |
269 | { | |
270 | DEFINE_WAIT(wait); | |
271 | int status = -EINTR; | |
272 | ||
273 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
274 | if (!signalled ()) { | |
275 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 276 | try_to_freeze(); |
1da177e4 LT |
277 | if (!signalled ()) |
278 | status = 0; | |
279 | } | |
280 | finish_wait(queue, &wait); | |
281 | return status; | |
282 | } | |
283 | ||
284 | /* | |
285 | * Generic NLM call | |
286 | */ | |
287 | static int | |
288 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
289 | { | |
290 | struct nlm_host *host = req->a_host; | |
291 | struct rpc_clnt *clnt; | |
292 | struct nlm_args *argp = &req->a_args; | |
293 | struct nlm_res *resp = &req->a_res; | |
294 | struct rpc_message msg = { | |
295 | .rpc_argp = argp, | |
296 | .rpc_resp = resp, | |
297 | }; | |
298 | int status; | |
299 | ||
300 | dprintk("lockd: call procedure %d on %s\n", | |
301 | (int)proc, host->h_name); | |
302 | ||
303 | do { | |
304 | if (host->h_reclaiming && !argp->reclaim) | |
305 | goto in_grace_period; | |
306 | ||
307 | /* If we have no RPC client yet, create one. */ | |
308 | if ((clnt = nlm_bind_host(host)) == NULL) | |
309 | return -ENOLCK; | |
310 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
311 | ||
312 | /* Perform the RPC call. If an error occurs, try again */ | |
313 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
314 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
315 | switch (status) { | |
316 | case -EPROTONOSUPPORT: | |
317 | status = -EINVAL; | |
318 | break; | |
319 | case -ECONNREFUSED: | |
320 | case -ETIMEDOUT: | |
321 | case -ENOTCONN: | |
322 | nlm_rebind_host(host); | |
323 | status = -EAGAIN; | |
324 | break; | |
325 | case -ERESTARTSYS: | |
326 | return signalled () ? -EINTR : status; | |
327 | default: | |
328 | break; | |
329 | } | |
330 | break; | |
331 | } else | |
332 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
333 | dprintk("lockd: server in grace period\n"); | |
334 | if (argp->reclaim) { | |
335 | printk(KERN_WARNING | |
336 | "lockd: spurious grace period reject?!\n"); | |
337 | return -ENOLCK; | |
338 | } | |
339 | } else { | |
340 | if (!argp->reclaim) { | |
341 | /* We appear to be out of the grace period */ | |
342 | wake_up_all(&host->h_gracewait); | |
343 | } | |
344 | dprintk("lockd: server returns status %d\n", resp->status); | |
345 | return 0; /* Okay, call complete */ | |
346 | } | |
347 | ||
348 | in_grace_period: | |
349 | /* | |
350 | * The server has rebooted and appears to be in the grace | |
351 | * period during which locks are only allowed to be | |
352 | * reclaimed. | |
353 | * We can only back off and try again later. | |
354 | */ | |
355 | status = nlm_wait_on_grace(&host->h_gracewait); | |
356 | } while (status == 0); | |
357 | ||
358 | return status; | |
359 | } | |
360 | ||
361 | /* | |
362 | * Generic NLM call, async version. | |
363 | */ | |
963d8fe5 | 364 | int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
365 | { |
366 | struct nlm_host *host = req->a_host; | |
367 | struct rpc_clnt *clnt; | |
368 | struct rpc_message msg = { | |
369 | .rpc_argp = &req->a_args, | |
370 | .rpc_resp = &req->a_res, | |
371 | }; | |
372 | int status; | |
373 | ||
374 | dprintk("lockd: call procedure %d on %s (async)\n", | |
375 | (int)proc, host->h_name); | |
376 | ||
377 | /* If we have no RPC client yet, create one. */ | |
378 | if ((clnt = nlm_bind_host(host)) == NULL) | |
379 | return -ENOLCK; | |
380 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
381 | ||
382 | /* bootstrap and kick off the async RPC call */ | |
963d8fe5 | 383 | status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req); |
1da177e4 LT |
384 | |
385 | return status; | |
386 | } | |
387 | ||
963d8fe5 | 388 | static int nlmclnt_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
389 | { |
390 | struct nlm_host *host = req->a_host; | |
391 | struct rpc_clnt *clnt; | |
392 | struct nlm_args *argp = &req->a_args; | |
393 | struct nlm_res *resp = &req->a_res; | |
394 | struct rpc_message msg = { | |
395 | .rpc_argp = argp, | |
396 | .rpc_resp = resp, | |
397 | }; | |
398 | int status; | |
399 | ||
400 | dprintk("lockd: call procedure %d on %s (async)\n", | |
401 | (int)proc, host->h_name); | |
402 | ||
403 | /* If we have no RPC client yet, create one. */ | |
404 | if ((clnt = nlm_bind_host(host)) == NULL) | |
405 | return -ENOLCK; | |
406 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
407 | ||
408 | /* Increment host refcount */ | |
409 | nlm_get_host(host); | |
410 | /* bootstrap and kick off the async RPC call */ | |
963d8fe5 | 411 | status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req); |
1da177e4 LT |
412 | if (status < 0) |
413 | nlm_release_host(host); | |
414 | return status; | |
415 | } | |
416 | ||
417 | /* | |
418 | * TEST for the presence of a conflicting lock | |
419 | */ | |
420 | static int | |
421 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
422 | { | |
423 | int status; | |
424 | ||
425 | status = nlmclnt_call(req, NLMPROC_TEST); | |
426 | nlmclnt_release_lockargs(req); | |
427 | if (status < 0) | |
428 | return status; | |
429 | ||
430 | status = req->a_res.status; | |
431 | if (status == NLM_LCK_GRANTED) { | |
432 | fl->fl_type = F_UNLCK; | |
433 | } if (status == NLM_LCK_DENIED) { | |
434 | /* | |
435 | * Report the conflicting lock back to the application. | |
436 | */ | |
e4cd038a TM |
437 | fl->fl_start = req->a_res.lock.fl.fl_start; |
438 | fl->fl_end = req->a_res.lock.fl.fl_start; | |
439 | fl->fl_type = req->a_res.lock.fl.fl_type; | |
1da177e4 LT |
440 | fl->fl_pid = 0; |
441 | } else { | |
442 | return nlm_stat_to_errno(req->a_res.status); | |
443 | } | |
444 | ||
445 | return 0; | |
446 | } | |
447 | ||
448 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
449 | { | |
4c060b53 TM |
450 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
451 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
452 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
453 | } |
454 | ||
455 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
456 | { | |
4c060b53 | 457 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 458 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
459 | } |
460 | ||
461 | static struct file_lock_operations nlmclnt_lock_ops = { | |
462 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
463 | .fl_release_private = nlmclnt_locks_release_private, | |
464 | }; | |
465 | ||
466 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
467 | { | |
468 | BUG_ON(fl->fl_ops != NULL); | |
469 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 470 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 471 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
472 | fl->fl_ops = &nlmclnt_lock_ops; |
473 | } | |
474 | ||
475 | static void do_vfs_lock(struct file_lock *fl) | |
476 | { | |
477 | int res = 0; | |
478 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
479 | case FL_POSIX: | |
480 | res = posix_lock_file_wait(fl->fl_file, fl); | |
481 | break; | |
482 | case FL_FLOCK: | |
483 | res = flock_lock_file_wait(fl->fl_file, fl); | |
484 | break; | |
485 | default: | |
486 | BUG(); | |
487 | } | |
488 | if (res < 0) | |
489 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", | |
490 | __FUNCTION__); | |
491 | } | |
492 | ||
493 | /* | |
494 | * LOCK: Try to create a lock | |
495 | * | |
496 | * Programmer Harassment Alert | |
497 | * | |
498 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
499 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
500 | * the lock could be granted. This way, our local process could hang | |
501 | * around forever waiting for the callback. | |
502 | * | |
503 | * Solution A: Implement busy-waiting | |
504 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
505 | * | |
506 | * For now I am implementing solution A, because I hate the idea of | |
507 | * re-implementing lockd for a third time in two months. The async | |
508 | * calls shouldn't be too hard to do, however. | |
509 | * | |
510 | * This is one of the lovely things about standards in the NFS area: | |
511 | * they're so soft and squishy you can't really blame HP for doing this. | |
512 | */ | |
513 | static int | |
514 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
515 | { | |
516 | struct nlm_host *host = req->a_host; | |
517 | struct nlm_res *resp = &req->a_res; | |
3a649b88 TM |
518 | struct nlm_wait *block = NULL; |
519 | int status = -ENOLCK; | |
1da177e4 LT |
520 | |
521 | if (!host->h_monitored && nsm_monitor(host) < 0) { | |
522 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", | |
523 | host->h_name); | |
1da177e4 LT |
524 | goto out; |
525 | } | |
526 | ||
3a649b88 | 527 | block = nlmclnt_prepare_block(host, fl); |
ecdbf769 TM |
528 | for(;;) { |
529 | status = nlmclnt_call(req, NLMPROC_LOCK); | |
530 | if (status < 0) | |
531 | goto out_unblock; | |
3a649b88 | 532 | if (!req->a_args.block) |
ecdbf769 | 533 | break; |
ecdbf769 TM |
534 | /* Did a reclaimer thread notify us of a server reboot? */ |
535 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) | |
536 | continue; | |
537 | if (resp->status != NLM_LCK_BLOCKED) | |
538 | break; | |
3a649b88 TM |
539 | /* Wait on an NLM blocking lock */ |
540 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
541 | /* if we were interrupted. Send a CANCEL request to the server | |
ecdbf769 TM |
542 | * and exit |
543 | */ | |
3a649b88 TM |
544 | if (status < 0) |
545 | goto out_unblock; | |
546 | if (resp->status != NLM_LCK_BLOCKED) | |
547 | break; | |
ecdbf769 | 548 | } |
1da177e4 LT |
549 | |
550 | if (resp->status == NLM_LCK_GRANTED) { | |
551 | fl->fl_u.nfs_fl.state = host->h_state; | |
1da177e4 | 552 | fl->fl_flags |= FL_SLEEP; |
4c060b53 | 553 | /* Ensure the resulting lock will get added to granted list */ |
1da177e4 LT |
554 | do_vfs_lock(fl); |
555 | } | |
556 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 557 | out_unblock: |
3a649b88 | 558 | nlmclnt_finish_block(block); |
ecdbf769 TM |
559 | /* Cancel the blocked request if it is still pending */ |
560 | if (resp->status == NLM_LCK_BLOCKED) | |
16fb2425 | 561 | nlmclnt_cancel(host, req->a_args.block, fl); |
1da177e4 LT |
562 | out: |
563 | nlmclnt_release_lockargs(req); | |
564 | return status; | |
565 | } | |
566 | ||
567 | /* | |
568 | * RECLAIM: Try to reclaim a lock | |
569 | */ | |
570 | int | |
571 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
572 | { | |
573 | struct nlm_rqst reqst, *req; | |
574 | int status; | |
575 | ||
576 | req = &reqst; | |
577 | memset(req, 0, sizeof(*req)); | |
578 | locks_init_lock(&req->a_args.lock.fl); | |
579 | locks_init_lock(&req->a_res.lock.fl); | |
580 | req->a_host = host; | |
581 | req->a_flags = 0; | |
582 | ||
583 | /* Set up the argument struct */ | |
584 | nlmclnt_setlockargs(req, fl); | |
585 | req->a_args.reclaim = 1; | |
586 | ||
587 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
588 | && req->a_res.status == NLM_LCK_GRANTED) | |
589 | return 0; | |
590 | ||
591 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
592 | "(errno %d, status %d)\n", fl->fl_pid, | |
593 | status, req->a_res.status); | |
594 | ||
595 | /* | |
596 | * FIXME: This is a serious failure. We can | |
597 | * | |
598 | * a. Ignore the problem | |
599 | * b. Send the owning process some signal (Linux doesn't have | |
600 | * SIGLOST, though...) | |
601 | * c. Retry the operation | |
602 | * | |
603 | * Until someone comes up with a simple implementation | |
604 | * for b or c, I'll choose option a. | |
605 | */ | |
606 | ||
607 | return -ENOLCK; | |
608 | } | |
609 | ||
610 | /* | |
611 | * UNLOCK: remove an existing lock | |
612 | */ | |
613 | static int | |
614 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
615 | { | |
616 | struct nlm_res *resp = &req->a_res; | |
617 | int status; | |
618 | ||
30f4e20a TM |
619 | /* |
620 | * Note: the server is supposed to either grant us the unlock | |
621 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
622 | * case, we want to unlock. | |
623 | */ | |
624 | do_vfs_lock(fl); | |
625 | ||
1da177e4 LT |
626 | if (req->a_flags & RPC_TASK_ASYNC) { |
627 | status = nlmclnt_async_call(req, NLMPROC_UNLOCK, | |
963d8fe5 | 628 | &nlmclnt_unlock_ops); |
1da177e4 LT |
629 | /* Hrmf... Do the unlock early since locks_remove_posix() |
630 | * really expects us to free the lock synchronously */ | |
1da177e4 LT |
631 | if (status < 0) { |
632 | nlmclnt_release_lockargs(req); | |
633 | kfree(req); | |
634 | } | |
635 | return status; | |
636 | } | |
637 | ||
638 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
639 | nlmclnt_release_lockargs(req); | |
640 | if (status < 0) | |
641 | return status; | |
642 | ||
1da177e4 LT |
643 | if (resp->status == NLM_LCK_GRANTED) |
644 | return 0; | |
645 | ||
646 | if (resp->status != NLM_LCK_DENIED_NOLOCKS) | |
647 | printk("lockd: unexpected unlock status: %d\n", resp->status); | |
648 | ||
649 | /* What to do now? I'm out of my depth... */ | |
650 | ||
651 | return -ENOLCK; | |
652 | } | |
653 | ||
963d8fe5 | 654 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 655 | { |
963d8fe5 | 656 | struct nlm_rqst *req = data; |
1da177e4 LT |
657 | int status = req->a_res.status; |
658 | ||
659 | if (RPC_ASSASSINATED(task)) | |
660 | goto die; | |
661 | ||
662 | if (task->tk_status < 0) { | |
663 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
664 | goto retry_rebind; | |
665 | } | |
666 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
667 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
668 | goto retry_unlock; | |
669 | } | |
670 | if (status != NLM_LCK_GRANTED) | |
671 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
672 | die: | |
673 | nlm_release_host(req->a_host); | |
674 | nlmclnt_release_lockargs(req); | |
675 | kfree(req); | |
676 | return; | |
677 | retry_rebind: | |
678 | nlm_rebind_host(req->a_host); | |
679 | retry_unlock: | |
680 | rpc_restart_call(task); | |
681 | } | |
682 | ||
963d8fe5 TM |
683 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
684 | .rpc_call_done = nlmclnt_unlock_callback, | |
685 | }; | |
686 | ||
1da177e4 LT |
687 | /* |
688 | * Cancel a blocked lock request. | |
689 | * We always use an async RPC call for this in order not to hang a | |
690 | * process that has been Ctrl-C'ed. | |
691 | */ | |
16fb2425 | 692 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
693 | { |
694 | struct nlm_rqst *req; | |
695 | unsigned long flags; | |
696 | sigset_t oldset; | |
697 | int status; | |
698 | ||
699 | /* Block all signals while setting up call */ | |
700 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
701 | oldset = current->blocked; | |
702 | sigfillset(¤t->blocked); | |
703 | recalc_sigpending(); | |
704 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
705 | ||
706 | req = nlmclnt_alloc_call(); | |
707 | if (!req) | |
708 | return -ENOMEM; | |
709 | req->a_host = host; | |
710 | req->a_flags = RPC_TASK_ASYNC; | |
711 | ||
712 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 713 | req->a_args.block = block; |
1da177e4 | 714 | |
963d8fe5 | 715 | status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
1da177e4 LT |
716 | if (status < 0) { |
717 | nlmclnt_release_lockargs(req); | |
718 | kfree(req); | |
719 | } | |
720 | ||
721 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
722 | current->blocked = oldset; | |
723 | recalc_sigpending(); | |
724 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
725 | ||
726 | return status; | |
727 | } | |
728 | ||
963d8fe5 | 729 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 730 | { |
963d8fe5 | 731 | struct nlm_rqst *req = data; |
1da177e4 LT |
732 | |
733 | if (RPC_ASSASSINATED(task)) | |
734 | goto die; | |
735 | ||
736 | if (task->tk_status < 0) { | |
737 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
738 | task->tk_status); | |
739 | goto retry_cancel; | |
740 | } | |
741 | ||
742 | dprintk("lockd: cancel status %d (task %d)\n", | |
743 | req->a_res.status, task->tk_pid); | |
744 | ||
745 | switch (req->a_res.status) { | |
746 | case NLM_LCK_GRANTED: | |
747 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 748 | case NLM_LCK_DENIED: |
1da177e4 LT |
749 | /* Everything's good */ |
750 | break; | |
751 | case NLM_LCK_DENIED_NOLOCKS: | |
752 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
753 | goto retry_cancel; | |
754 | default: | |
755 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
756 | req->a_res.status); | |
757 | } | |
758 | ||
759 | die: | |
760 | nlm_release_host(req->a_host); | |
761 | nlmclnt_release_lockargs(req); | |
762 | kfree(req); | |
763 | return; | |
764 | ||
765 | retry_cancel: | |
aaaa9942 TM |
766 | /* Don't ever retry more than 3 times */ |
767 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
768 | goto die; | |
1da177e4 LT |
769 | nlm_rebind_host(req->a_host); |
770 | rpc_restart_call(task); | |
771 | rpc_delay(task, 30 * HZ); | |
772 | } | |
773 | ||
963d8fe5 TM |
774 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
775 | .rpc_call_done = nlmclnt_cancel_callback, | |
776 | }; | |
777 | ||
1da177e4 LT |
778 | /* |
779 | * Convert an NLM status code to a generic kernel errno | |
780 | */ | |
781 | static int | |
782 | nlm_stat_to_errno(u32 status) | |
783 | { | |
784 | switch(status) { | |
785 | case NLM_LCK_GRANTED: | |
786 | return 0; | |
787 | case NLM_LCK_DENIED: | |
788 | return -EAGAIN; | |
789 | case NLM_LCK_DENIED_NOLOCKS: | |
790 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
791 | return -ENOLCK; | |
792 | case NLM_LCK_BLOCKED: | |
793 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
794 | return -ENOLCK; | |
795 | #ifdef CONFIG_LOCKD_V4 | |
796 | case NLM_DEADLCK: | |
797 | return -EDEADLK; | |
798 | case NLM_ROFS: | |
799 | return -EROFS; | |
800 | case NLM_STALE_FH: | |
801 | return -ESTALE; | |
802 | case NLM_FBIG: | |
803 | return -EOVERFLOW; | |
804 | case NLM_FAILED: | |
805 | return -ENOLCK; | |
806 | #endif | |
807 | } | |
808 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
809 | return -ENOLCK; | |
810 | } |