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Commit | Line | Data |
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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 | ||
1da177e4 LT |
9 | #include <linux/module.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> | |
7dfb7103 | 15 | #include <linux/freezer.h> |
1da177e4 LT |
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) | |
ecdbf769 | 23 | #define NLMCLNT_POLL_TIMEOUT (30*HZ) |
aaaa9942 | 24 | #define NLMCLNT_MAX_RETRIES 3 |
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 *); | |
e8c5c045 | 29 | static int nlm_stat_to_errno(__be32 stat); |
1da177e4 | 30 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); |
16fb2425 | 31 | static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
1da177e4 | 32 | |
963d8fe5 TM |
33 | static const struct rpc_call_ops nlmclnt_unlock_ops; |
34 | static const struct rpc_call_ops nlmclnt_cancel_ops; | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * Cookie counter for NLM requests | |
38 | */ | |
031d869d | 39 | static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
1da177e4 | 40 | |
031d869d | 41 | void nlmclnt_next_cookie(struct nlm_cookie *c) |
1da177e4 | 42 | { |
031d869d OK |
43 | u32 cookie = atomic_inc_return(&nlm_cookie); |
44 | ||
45 | memcpy(c->data, &cookie, 4); | |
1da177e4 | 46 | c->len=4; |
1da177e4 LT |
47 | } |
48 | ||
49 | static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner) | |
50 | { | |
51 | atomic_inc(&lockowner->count); | |
52 | return lockowner; | |
53 | } | |
54 | ||
55 | static void nlm_put_lockowner(struct nlm_lockowner *lockowner) | |
56 | { | |
57 | if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) | |
58 | return; | |
59 | list_del(&lockowner->list); | |
60 | spin_unlock(&lockowner->host->h_lock); | |
61 | nlm_release_host(lockowner->host); | |
62 | kfree(lockowner); | |
63 | } | |
64 | ||
65 | static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) | |
66 | { | |
67 | struct nlm_lockowner *lockowner; | |
68 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
69 | if (lockowner->pid == pid) | |
70 | return -EBUSY; | |
71 | } | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) | |
76 | { | |
77 | uint32_t res; | |
78 | do { | |
79 | res = host->h_pidcount++; | |
80 | } while (nlm_pidbusy(host, res) < 0); | |
81 | return res; | |
82 | } | |
83 | ||
84 | static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
85 | { | |
86 | struct nlm_lockowner *lockowner; | |
87 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
88 | if (lockowner->owner != owner) | |
89 | continue; | |
90 | return nlm_get_lockowner(lockowner); | |
91 | } | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
96 | { | |
97 | struct nlm_lockowner *res, *new = NULL; | |
98 | ||
99 | spin_lock(&host->h_lock); | |
100 | res = __nlm_find_lockowner(host, owner); | |
101 | if (res == NULL) { | |
102 | spin_unlock(&host->h_lock); | |
f52720ca | 103 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
1da177e4 LT |
104 | spin_lock(&host->h_lock); |
105 | res = __nlm_find_lockowner(host, owner); | |
106 | if (res == NULL && new != NULL) { | |
107 | res = new; | |
108 | atomic_set(&new->count, 1); | |
109 | new->owner = owner; | |
110 | new->pid = __nlm_alloc_pid(host); | |
111 | new->host = nlm_get_host(host); | |
112 | list_add(&new->list, &host->h_lockowners); | |
113 | new = NULL; | |
114 | } | |
115 | } | |
116 | spin_unlock(&host->h_lock); | |
f99d49ad | 117 | kfree(new); |
1da177e4 LT |
118 | return res; |
119 | } | |
120 | ||
121 | /* | |
122 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
123 | */ | |
124 | static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) | |
125 | { | |
126 | struct nlm_args *argp = &req->a_args; | |
127 | struct nlm_lock *lock = &argp->lock; | |
128 | ||
129 | nlmclnt_next_cookie(&argp->cookie); | |
130 | argp->state = nsm_local_state; | |
225a719f | 131 | memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh)); |
e9ff3990 | 132 | lock->caller = utsname()->nodename; |
1da177e4 | 133 | lock->oh.data = req->a_owner; |
7bab377f TM |
134 | lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
135 | (unsigned int)fl->fl_u.nfs_fl.owner->pid, | |
e9ff3990 | 136 | utsname()->nodename); |
7bab377f | 137 | lock->svid = fl->fl_u.nfs_fl.owner->pid; |
3a649b88 TM |
138 | lock->fl.fl_start = fl->fl_start; |
139 | lock->fl.fl_end = fl->fl_end; | |
140 | lock->fl.fl_type = fl->fl_type; | |
1da177e4 LT |
141 | } |
142 | ||
143 | static void nlmclnt_release_lockargs(struct nlm_rqst *req) | |
144 | { | |
3a649b88 | 145 | BUG_ON(req->a_args.lock.fl.fl_ops != NULL); |
1da177e4 LT |
146 | } |
147 | ||
1093a60e CL |
148 | /** |
149 | * nlmclnt_proc - Perform a single client-side lock request | |
150 | * @host: address of a valid nlm_host context representing the NLM server | |
151 | * @cmd: fcntl-style file lock operation to perform | |
152 | * @fl: address of arguments for the lock operation | |
153 | * | |
1da177e4 | 154 | */ |
1093a60e | 155 | int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl) |
1da177e4 | 156 | { |
92737230 | 157 | struct nlm_rqst *call; |
1da177e4 LT |
158 | sigset_t oldset; |
159 | unsigned long flags; | |
1093a60e | 160 | int status; |
1da177e4 | 161 | |
1093a60e | 162 | nlm_get_host(host); |
92737230 TM |
163 | call = nlm_alloc_call(host); |
164 | if (call == NULL) | |
165 | return -ENOMEM; | |
1da177e4 | 166 | |
92737230 TM |
167 | nlmclnt_locks_init_private(fl, host); |
168 | /* Set up the argument struct */ | |
169 | nlmclnt_setlockargs(call, fl); | |
1da177e4 LT |
170 | |
171 | /* Keep the old signal mask */ | |
172 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
173 | oldset = current->blocked; | |
174 | ||
175 | /* If we're cleaning up locks because the process is exiting, | |
176 | * perform the RPC call asynchronously. */ | |
177 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) | |
178 | && fl->fl_type == F_UNLCK | |
179 | && (current->flags & PF_EXITING)) { | |
180 | sigfillset(¤t->blocked); /* Mask all signals */ | |
181 | recalc_sigpending(); | |
1da177e4 | 182 | |
1da177e4 | 183 | call->a_flags = RPC_TASK_ASYNC; |
1da177e4 | 184 | } |
92737230 | 185 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
1da177e4 LT |
186 | |
187 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { | |
188 | if (fl->fl_type != F_UNLCK) { | |
189 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
190 | status = nlmclnt_lock(call, fl); | |
191 | } else | |
192 | status = nlmclnt_unlock(call, fl); | |
193 | } else if (IS_GETLK(cmd)) | |
194 | status = nlmclnt_test(call, fl); | |
195 | else | |
196 | status = -EINVAL; | |
197 | ||
92737230 TM |
198 | fl->fl_ops->fl_release_private(fl); |
199 | fl->fl_ops = NULL; | |
200 | ||
1da177e4 LT |
201 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
202 | current->blocked = oldset; | |
203 | recalc_sigpending(); | |
204 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
205 | ||
1da177e4 | 206 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
207 | return status; |
208 | } | |
1093a60e | 209 | EXPORT_SYMBOL_GPL(nlmclnt_proc); |
1da177e4 LT |
210 | |
211 | /* | |
212 | * Allocate an NLM RPC call struct | |
92737230 TM |
213 | * |
214 | * Note: the caller must hold a reference to host. In case of failure, | |
215 | * this reference will be released. | |
1da177e4 | 216 | */ |
92737230 | 217 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
218 | { |
219 | struct nlm_rqst *call; | |
220 | ||
36943fa4 TM |
221 | for(;;) { |
222 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
223 | if (call != NULL) { | |
1da177e4 LT |
224 | locks_init_lock(&call->a_args.lock.fl); |
225 | locks_init_lock(&call->a_res.lock.fl); | |
92737230 | 226 | call->a_host = host; |
1da177e4 LT |
227 | return call; |
228 | } | |
36943fa4 TM |
229 | if (signalled()) |
230 | break; | |
92737230 | 231 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 232 | schedule_timeout_interruptible(5*HZ); |
1da177e4 | 233 | } |
92737230 | 234 | nlm_release_host(host); |
1da177e4 LT |
235 | return NULL; |
236 | } | |
237 | ||
92737230 TM |
238 | void nlm_release_call(struct nlm_rqst *call) |
239 | { | |
240 | nlm_release_host(call->a_host); | |
241 | nlmclnt_release_lockargs(call); | |
242 | kfree(call); | |
243 | } | |
244 | ||
245 | static void nlmclnt_rpc_release(void *data) | |
246 | { | |
65fdf7d2 | 247 | nlm_release_call(data); |
92737230 TM |
248 | } |
249 | ||
1da177e4 LT |
250 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
251 | { | |
252 | DEFINE_WAIT(wait); | |
253 | int status = -EINTR; | |
254 | ||
255 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
256 | if (!signalled ()) { | |
257 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 258 | try_to_freeze(); |
1da177e4 LT |
259 | if (!signalled ()) |
260 | status = 0; | |
261 | } | |
262 | finish_wait(queue, &wait); | |
263 | return status; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Generic NLM call | |
268 | */ | |
269 | static int | |
270 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
271 | { | |
272 | struct nlm_host *host = req->a_host; | |
273 | struct rpc_clnt *clnt; | |
274 | struct nlm_args *argp = &req->a_args; | |
275 | struct nlm_res *resp = &req->a_res; | |
276 | struct rpc_message msg = { | |
277 | .rpc_argp = argp, | |
278 | .rpc_resp = resp, | |
279 | }; | |
280 | int status; | |
281 | ||
282 | dprintk("lockd: call procedure %d on %s\n", | |
283 | (int)proc, host->h_name); | |
284 | ||
285 | do { | |
286 | if (host->h_reclaiming && !argp->reclaim) | |
287 | goto in_grace_period; | |
288 | ||
289 | /* If we have no RPC client yet, create one. */ | |
290 | if ((clnt = nlm_bind_host(host)) == NULL) | |
291 | return -ENOLCK; | |
292 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
293 | ||
294 | /* Perform the RPC call. If an error occurs, try again */ | |
295 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
296 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
297 | switch (status) { | |
298 | case -EPROTONOSUPPORT: | |
299 | status = -EINVAL; | |
300 | break; | |
301 | case -ECONNREFUSED: | |
302 | case -ETIMEDOUT: | |
303 | case -ENOTCONN: | |
304 | nlm_rebind_host(host); | |
305 | status = -EAGAIN; | |
306 | break; | |
307 | case -ERESTARTSYS: | |
308 | return signalled () ? -EINTR : status; | |
309 | default: | |
310 | break; | |
311 | } | |
312 | break; | |
313 | } else | |
e8c5c045 | 314 | if (resp->status == nlm_lck_denied_grace_period) { |
1da177e4 LT |
315 | dprintk("lockd: server in grace period\n"); |
316 | if (argp->reclaim) { | |
317 | printk(KERN_WARNING | |
318 | "lockd: spurious grace period reject?!\n"); | |
319 | return -ENOLCK; | |
320 | } | |
321 | } else { | |
322 | if (!argp->reclaim) { | |
323 | /* We appear to be out of the grace period */ | |
324 | wake_up_all(&host->h_gracewait); | |
325 | } | |
326 | dprintk("lockd: server returns status %d\n", resp->status); | |
327 | return 0; /* Okay, call complete */ | |
328 | } | |
329 | ||
330 | in_grace_period: | |
331 | /* | |
332 | * The server has rebooted and appears to be in the grace | |
333 | * period during which locks are only allowed to be | |
334 | * reclaimed. | |
335 | * We can only back off and try again later. | |
336 | */ | |
337 | status = nlm_wait_on_grace(&host->h_gracewait); | |
338 | } while (status == 0); | |
339 | ||
340 | return status; | |
341 | } | |
342 | ||
343 | /* | |
344 | * Generic NLM call, async version. | |
345 | */ | |
d4716624 | 346 | static int __nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
347 | { |
348 | struct nlm_host *host = req->a_host; | |
349 | struct rpc_clnt *clnt; | |
1da177e4 LT |
350 | |
351 | dprintk("lockd: call procedure %d on %s (async)\n", | |
352 | (int)proc, host->h_name); | |
353 | ||
354 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
355 | clnt = nlm_bind_host(host); |
356 | if (clnt == NULL) | |
357 | goto out_err; | |
d4716624 | 358 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
1da177e4 | 359 | |
1da177e4 | 360 | /* bootstrap and kick off the async RPC call */ |
a995e9eb | 361 | return rpc_call_async(clnt, msg, RPC_TASK_ASYNC, tk_ops, req); |
92737230 | 362 | out_err: |
a995e9eb TM |
363 | tk_ops->rpc_release(req); |
364 | return -ENOLCK; | |
1da177e4 LT |
365 | } |
366 | ||
d4716624 TM |
367 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
368 | { | |
369 | struct rpc_message msg = { | |
370 | .rpc_argp = &req->a_args, | |
371 | .rpc_resp = &req->a_res, | |
372 | }; | |
373 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
374 | } | |
375 | ||
376 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
377 | { | |
378 | struct rpc_message msg = { | |
379 | .rpc_argp = &req->a_res, | |
380 | }; | |
381 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
382 | } | |
383 | ||
1da177e4 LT |
384 | /* |
385 | * TEST for the presence of a conflicting lock | |
386 | */ | |
387 | static int | |
388 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
389 | { | |
390 | int status; | |
391 | ||
392 | status = nlmclnt_call(req, NLMPROC_TEST); | |
1da177e4 | 393 | if (status < 0) |
92737230 | 394 | goto out; |
1da177e4 | 395 | |
92737230 | 396 | switch (req->a_res.status) { |
e8c5c045 | 397 | case nlm_granted: |
92737230 TM |
398 | fl->fl_type = F_UNLCK; |
399 | break; | |
e8c5c045 | 400 | case nlm_lck_denied: |
92737230 TM |
401 | /* |
402 | * Report the conflicting lock back to the application. | |
403 | */ | |
404 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
405 | fl->fl_end = req->a_res.lock.fl.fl_start; | |
406 | fl->fl_type = req->a_res.lock.fl.fl_type; | |
407 | fl->fl_pid = 0; | |
408 | break; | |
409 | default: | |
410 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 411 | } |
92737230 TM |
412 | out: |
413 | nlm_release_call(req); | |
414 | return status; | |
1da177e4 LT |
415 | } |
416 | ||
417 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
418 | { | |
4c060b53 TM |
419 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
420 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
421 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
422 | } |
423 | ||
424 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
425 | { | |
4c060b53 | 426 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 427 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
428 | } |
429 | ||
430 | static struct file_lock_operations nlmclnt_lock_ops = { | |
431 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
432 | .fl_release_private = nlmclnt_locks_release_private, | |
433 | }; | |
434 | ||
435 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
436 | { | |
437 | BUG_ON(fl->fl_ops != NULL); | |
438 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 439 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 440 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
441 | fl->fl_ops = &nlmclnt_lock_ops; |
442 | } | |
443 | ||
9b073574 | 444 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
445 | { |
446 | int res = 0; | |
447 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
448 | case FL_POSIX: | |
449 | res = posix_lock_file_wait(fl->fl_file, fl); | |
450 | break; | |
451 | case FL_FLOCK: | |
452 | res = flock_lock_file_wait(fl->fl_file, fl); | |
453 | break; | |
454 | default: | |
455 | BUG(); | |
456 | } | |
9b073574 | 457 | return res; |
1da177e4 LT |
458 | } |
459 | ||
460 | /* | |
461 | * LOCK: Try to create a lock | |
462 | * | |
463 | * Programmer Harassment Alert | |
464 | * | |
465 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
466 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
467 | * the lock could be granted. This way, our local process could hang | |
468 | * around forever waiting for the callback. | |
469 | * | |
470 | * Solution A: Implement busy-waiting | |
471 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
472 | * | |
473 | * For now I am implementing solution A, because I hate the idea of | |
474 | * re-implementing lockd for a third time in two months. The async | |
475 | * calls shouldn't be too hard to do, however. | |
476 | * | |
477 | * This is one of the lovely things about standards in the NFS area: | |
478 | * they're so soft and squishy you can't really blame HP for doing this. | |
479 | */ | |
480 | static int | |
481 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
482 | { | |
483 | struct nlm_host *host = req->a_host; | |
484 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 485 | struct nlm_wait *block = NULL; |
01c3b861 | 486 | unsigned char fl_flags = fl->fl_flags; |
3a649b88 | 487 | int status = -ENOLCK; |
1da177e4 | 488 | |
977faf39 | 489 | if (nsm_monitor(host) < 0) { |
1da177e4 LT |
490 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", |
491 | host->h_name); | |
1da177e4 LT |
492 | goto out; |
493 | } | |
01c3b861 TM |
494 | fl->fl_flags |= FL_ACCESS; |
495 | status = do_vfs_lock(fl); | |
4a9af59f | 496 | fl->fl_flags = fl_flags; |
01c3b861 TM |
497 | if (status < 0) |
498 | goto out; | |
1da177e4 | 499 | |
3a649b88 | 500 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 501 | again: |
ecdbf769 | 502 | for(;;) { |
28df955a TM |
503 | /* Reboot protection */ |
504 | fl->fl_u.nfs_fl.state = host->h_state; | |
ecdbf769 TM |
505 | status = nlmclnt_call(req, NLMPROC_LOCK); |
506 | if (status < 0) | |
507 | goto out_unblock; | |
3a649b88 | 508 | if (!req->a_args.block) |
ecdbf769 | 509 | break; |
ecdbf769 | 510 | /* Did a reclaimer thread notify us of a server reboot? */ |
e8c5c045 | 511 | if (resp->status == nlm_lck_denied_grace_period) |
ecdbf769 | 512 | continue; |
e8c5c045 | 513 | if (resp->status != nlm_lck_blocked) |
ecdbf769 | 514 | break; |
3a649b88 TM |
515 | /* Wait on an NLM blocking lock */ |
516 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
517 | /* if we were interrupted. Send a CANCEL request to the server | |
ecdbf769 TM |
518 | * and exit |
519 | */ | |
3a649b88 TM |
520 | if (status < 0) |
521 | goto out_unblock; | |
e8c5c045 | 522 | if (resp->status != nlm_lck_blocked) |
3a649b88 | 523 | break; |
ecdbf769 | 524 | } |
1da177e4 | 525 | |
e8c5c045 | 526 | if (resp->status == nlm_granted) { |
28df955a TM |
527 | down_read(&host->h_rwsem); |
528 | /* Check whether or not the server has rebooted */ | |
529 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
530 | up_read(&host->h_rwsem); | |
531 | goto again; | |
532 | } | |
4c060b53 | 533 | /* Ensure the resulting lock will get added to granted list */ |
4a9af59f | 534 | fl->fl_flags |= FL_SLEEP; |
9b073574 TM |
535 | if (do_vfs_lock(fl) < 0) |
536 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); | |
28df955a | 537 | up_read(&host->h_rwsem); |
4a9af59f | 538 | fl->fl_flags = fl_flags; |
1da177e4 LT |
539 | } |
540 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 541 | out_unblock: |
3a649b88 | 542 | nlmclnt_finish_block(block); |
ecdbf769 | 543 | /* Cancel the blocked request if it is still pending */ |
e8c5c045 | 544 | if (resp->status == nlm_lck_blocked) |
16fb2425 | 545 | nlmclnt_cancel(host, req->a_args.block, fl); |
1da177e4 | 546 | out: |
92737230 | 547 | nlm_release_call(req); |
1da177e4 LT |
548 | return status; |
549 | } | |
550 | ||
551 | /* | |
552 | * RECLAIM: Try to reclaim a lock | |
553 | */ | |
554 | int | |
555 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
556 | { | |
557 | struct nlm_rqst reqst, *req; | |
558 | int status; | |
559 | ||
560 | req = &reqst; | |
561 | memset(req, 0, sizeof(*req)); | |
562 | locks_init_lock(&req->a_args.lock.fl); | |
563 | locks_init_lock(&req->a_res.lock.fl); | |
564 | req->a_host = host; | |
565 | req->a_flags = 0; | |
566 | ||
567 | /* Set up the argument struct */ | |
568 | nlmclnt_setlockargs(req, fl); | |
569 | req->a_args.reclaim = 1; | |
570 | ||
571 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
e8c5c045 | 572 | && req->a_res.status == nlm_granted) |
1da177e4 LT |
573 | return 0; |
574 | ||
575 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
576 | "(errno %d, status %d)\n", fl->fl_pid, | |
e8c5c045 | 577 | status, ntohl(req->a_res.status)); |
1da177e4 LT |
578 | |
579 | /* | |
580 | * FIXME: This is a serious failure. We can | |
581 | * | |
582 | * a. Ignore the problem | |
583 | * b. Send the owning process some signal (Linux doesn't have | |
584 | * SIGLOST, though...) | |
585 | * c. Retry the operation | |
586 | * | |
587 | * Until someone comes up with a simple implementation | |
588 | * for b or c, I'll choose option a. | |
589 | */ | |
590 | ||
591 | return -ENOLCK; | |
592 | } | |
593 | ||
594 | /* | |
595 | * UNLOCK: remove an existing lock | |
596 | */ | |
597 | static int | |
598 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
599 | { | |
28df955a | 600 | struct nlm_host *host = req->a_host; |
1da177e4 | 601 | struct nlm_res *resp = &req->a_res; |
4a9af59f TM |
602 | int status; |
603 | unsigned char fl_flags = fl->fl_flags; | |
1da177e4 | 604 | |
30f4e20a TM |
605 | /* |
606 | * Note: the server is supposed to either grant us the unlock | |
607 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
608 | * case, we want to unlock. | |
609 | */ | |
9b073574 | 610 | fl->fl_flags |= FL_EXISTS; |
28df955a | 611 | down_read(&host->h_rwsem); |
4a9af59f TM |
612 | status = do_vfs_lock(fl); |
613 | up_read(&host->h_rwsem); | |
614 | fl->fl_flags = fl_flags; | |
615 | if (status == -ENOENT) { | |
616 | status = 0; | |
9b073574 TM |
617 | goto out; |
618 | } | |
30f4e20a | 619 | |
92737230 TM |
620 | if (req->a_flags & RPC_TASK_ASYNC) |
621 | return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 LT |
622 | |
623 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
1da177e4 | 624 | if (status < 0) |
92737230 | 625 | goto out; |
1da177e4 | 626 | |
e8c5c045 | 627 | if (resp->status == nlm_granted) |
92737230 | 628 | goto out; |
1da177e4 | 629 | |
e8c5c045 | 630 | if (resp->status != nlm_lck_denied_nolocks) |
1da177e4 | 631 | printk("lockd: unexpected unlock status: %d\n", resp->status); |
1da177e4 | 632 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
633 | status = -ENOLCK; |
634 | out: | |
635 | nlm_release_call(req); | |
636 | return status; | |
1da177e4 LT |
637 | } |
638 | ||
963d8fe5 | 639 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 640 | { |
963d8fe5 | 641 | struct nlm_rqst *req = data; |
e8c5c045 | 642 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
643 | |
644 | if (RPC_ASSASSINATED(task)) | |
645 | goto die; | |
646 | ||
647 | if (task->tk_status < 0) { | |
648 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
649 | goto retry_rebind; | |
650 | } | |
651 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
652 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
653 | goto retry_unlock; | |
654 | } | |
655 | if (status != NLM_LCK_GRANTED) | |
656 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
657 | die: | |
1da177e4 LT |
658 | return; |
659 | retry_rebind: | |
660 | nlm_rebind_host(req->a_host); | |
661 | retry_unlock: | |
662 | rpc_restart_call(task); | |
663 | } | |
664 | ||
963d8fe5 TM |
665 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
666 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 667 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
668 | }; |
669 | ||
1da177e4 LT |
670 | /* |
671 | * Cancel a blocked lock request. | |
672 | * We always use an async RPC call for this in order not to hang a | |
673 | * process that has been Ctrl-C'ed. | |
674 | */ | |
16fb2425 | 675 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
676 | { |
677 | struct nlm_rqst *req; | |
678 | unsigned long flags; | |
679 | sigset_t oldset; | |
680 | int status; | |
681 | ||
682 | /* Block all signals while setting up call */ | |
683 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
684 | oldset = current->blocked; | |
685 | sigfillset(¤t->blocked); | |
686 | recalc_sigpending(); | |
687 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
688 | ||
92737230 | 689 | req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4 LT |
690 | if (!req) |
691 | return -ENOMEM; | |
1da177e4 LT |
692 | req->a_flags = RPC_TASK_ASYNC; |
693 | ||
694 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 695 | req->a_args.block = block; |
1da177e4 | 696 | |
92737230 | 697 | status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
1da177e4 LT |
698 | |
699 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
700 | current->blocked = oldset; | |
701 | recalc_sigpending(); | |
702 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
703 | ||
704 | return status; | |
705 | } | |
706 | ||
963d8fe5 | 707 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 708 | { |
963d8fe5 | 709 | struct nlm_rqst *req = data; |
e8c5c045 | 710 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
711 | |
712 | if (RPC_ASSASSINATED(task)) | |
713 | goto die; | |
714 | ||
715 | if (task->tk_status < 0) { | |
716 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
717 | task->tk_status); | |
718 | goto retry_cancel; | |
719 | } | |
720 | ||
c041b5ff | 721 | dprintk("lockd: cancel status %u (task %u)\n", |
e8c5c045 | 722 | status, task->tk_pid); |
1da177e4 | 723 | |
e8c5c045 | 724 | switch (status) { |
1da177e4 LT |
725 | case NLM_LCK_GRANTED: |
726 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 727 | case NLM_LCK_DENIED: |
1da177e4 LT |
728 | /* Everything's good */ |
729 | break; | |
730 | case NLM_LCK_DENIED_NOLOCKS: | |
731 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
732 | goto retry_cancel; | |
733 | default: | |
734 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
e8c5c045 | 735 | status); |
1da177e4 LT |
736 | } |
737 | ||
738 | die: | |
1da177e4 LT |
739 | return; |
740 | ||
741 | retry_cancel: | |
aaaa9942 TM |
742 | /* Don't ever retry more than 3 times */ |
743 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
744 | goto die; | |
1da177e4 LT |
745 | nlm_rebind_host(req->a_host); |
746 | rpc_restart_call(task); | |
747 | rpc_delay(task, 30 * HZ); | |
748 | } | |
749 | ||
963d8fe5 TM |
750 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
751 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 752 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
753 | }; |
754 | ||
1da177e4 LT |
755 | /* |
756 | * Convert an NLM status code to a generic kernel errno | |
757 | */ | |
758 | static int | |
e8c5c045 | 759 | nlm_stat_to_errno(__be32 status) |
1da177e4 | 760 | { |
e8c5c045 | 761 | switch(ntohl(status)) { |
1da177e4 LT |
762 | case NLM_LCK_GRANTED: |
763 | return 0; | |
764 | case NLM_LCK_DENIED: | |
765 | return -EAGAIN; | |
766 | case NLM_LCK_DENIED_NOLOCKS: | |
767 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
768 | return -ENOLCK; | |
769 | case NLM_LCK_BLOCKED: | |
770 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
771 | return -ENOLCK; | |
772 | #ifdef CONFIG_LOCKD_V4 | |
773 | case NLM_DEADLCK: | |
774 | return -EDEADLK; | |
775 | case NLM_ROFS: | |
776 | return -EROFS; | |
777 | case NLM_STALE_FH: | |
778 | return -ESTALE; | |
779 | case NLM_FBIG: | |
780 | return -EOVERFLOW; | |
781 | case NLM_FAILED: | |
782 | return -ENOLCK; | |
783 | #endif | |
784 | } | |
785 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
786 | return -ENOLCK; | |
787 | } |