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 | ||
1da177e4 | 9 | #include <linux/module.h> |
405f5571 | 10 | #include <linux/smp_lock.h> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
1da177e4 LT |
12 | #include <linux/types.h> |
13 | #include <linux/errno.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/nfs_fs.h> | |
16 | #include <linux/utsname.h> | |
7dfb7103 | 17 | #include <linux/freezer.h> |
1da177e4 LT |
18 | #include <linux/sunrpc/clnt.h> |
19 | #include <linux/sunrpc/svc.h> | |
20 | #include <linux/lockd/lockd.h> | |
1da177e4 LT |
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 *); | |
e8c5c045 | 30 | static int nlm_stat_to_errno(__be32 stat); |
1da177e4 | 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 | */ | |
031d869d | 40 | static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
1da177e4 | 41 | |
031d869d | 42 | void nlmclnt_next_cookie(struct nlm_cookie *c) |
1da177e4 | 43 | { |
031d869d OK |
44 | u32 cookie = atomic_inc_return(&nlm_cookie); |
45 | ||
46 | memcpy(c->data, &cookie, 4); | |
1da177e4 | 47 | c->len=4; |
1da177e4 LT |
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); | |
f52720ca | 104 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
1da177e4 LT |
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); | |
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; |
1093a60e | 158 | int status; |
1da177e4 | 159 | |
1093a60e | 160 | nlm_get_host(host); |
92737230 TM |
161 | call = nlm_alloc_call(host); |
162 | if (call == NULL) | |
163 | return -ENOMEM; | |
1da177e4 | 164 | |
92737230 TM |
165 | nlmclnt_locks_init_private(fl, host); |
166 | /* Set up the argument struct */ | |
167 | nlmclnt_setlockargs(call, fl); | |
1da177e4 | 168 | |
5cd973c4 | 169 | lock_kernel(); |
1da177e4 LT |
170 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { |
171 | if (fl->fl_type != F_UNLCK) { | |
172 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
173 | status = nlmclnt_lock(call, fl); | |
174 | } else | |
175 | status = nlmclnt_unlock(call, fl); | |
176 | } else if (IS_GETLK(cmd)) | |
177 | status = nlmclnt_test(call, fl); | |
178 | else | |
179 | status = -EINVAL; | |
180 | ||
92737230 TM |
181 | fl->fl_ops->fl_release_private(fl); |
182 | fl->fl_ops = NULL; | |
5cd973c4 | 183 | unlock_kernel(); |
92737230 | 184 | |
1da177e4 | 185 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
186 | return status; |
187 | } | |
1093a60e | 188 | EXPORT_SYMBOL_GPL(nlmclnt_proc); |
1da177e4 LT |
189 | |
190 | /* | |
191 | * Allocate an NLM RPC call struct | |
92737230 TM |
192 | * |
193 | * Note: the caller must hold a reference to host. In case of failure, | |
194 | * this reference will be released. | |
1da177e4 | 195 | */ |
92737230 | 196 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
197 | { |
198 | struct nlm_rqst *call; | |
199 | ||
36943fa4 TM |
200 | for(;;) { |
201 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
202 | if (call != NULL) { | |
5e7f37a7 | 203 | atomic_set(&call->a_count, 1); |
1da177e4 LT |
204 | locks_init_lock(&call->a_args.lock.fl); |
205 | locks_init_lock(&call->a_res.lock.fl); | |
92737230 | 206 | call->a_host = host; |
1da177e4 LT |
207 | return call; |
208 | } | |
36943fa4 TM |
209 | if (signalled()) |
210 | break; | |
92737230 | 211 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 212 | schedule_timeout_interruptible(5*HZ); |
1da177e4 | 213 | } |
92737230 | 214 | nlm_release_host(host); |
1da177e4 LT |
215 | return NULL; |
216 | } | |
217 | ||
92737230 TM |
218 | void nlm_release_call(struct nlm_rqst *call) |
219 | { | |
5e7f37a7 TM |
220 | if (!atomic_dec_and_test(&call->a_count)) |
221 | return; | |
92737230 TM |
222 | nlm_release_host(call->a_host); |
223 | nlmclnt_release_lockargs(call); | |
224 | kfree(call); | |
225 | } | |
226 | ||
227 | static void nlmclnt_rpc_release(void *data) | |
228 | { | |
a86dc496 | 229 | lock_kernel(); |
65fdf7d2 | 230 | nlm_release_call(data); |
a86dc496 | 231 | unlock_kernel(); |
92737230 TM |
232 | } |
233 | ||
1da177e4 LT |
234 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
235 | { | |
236 | DEFINE_WAIT(wait); | |
237 | int status = -EINTR; | |
238 | ||
239 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
240 | if (!signalled ()) { | |
241 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 242 | try_to_freeze(); |
1da177e4 LT |
243 | if (!signalled ()) |
244 | status = 0; | |
245 | } | |
246 | finish_wait(queue, &wait); | |
247 | return status; | |
248 | } | |
249 | ||
250 | /* | |
251 | * Generic NLM call | |
252 | */ | |
253 | static int | |
d11d10cc | 254 | nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc) |
1da177e4 LT |
255 | { |
256 | struct nlm_host *host = req->a_host; | |
257 | struct rpc_clnt *clnt; | |
258 | struct nlm_args *argp = &req->a_args; | |
259 | struct nlm_res *resp = &req->a_res; | |
260 | struct rpc_message msg = { | |
261 | .rpc_argp = argp, | |
262 | .rpc_resp = resp, | |
d11d10cc | 263 | .rpc_cred = cred, |
1da177e4 LT |
264 | }; |
265 | int status; | |
266 | ||
267 | dprintk("lockd: call procedure %d on %s\n", | |
268 | (int)proc, host->h_name); | |
269 | ||
270 | do { | |
271 | if (host->h_reclaiming && !argp->reclaim) | |
272 | goto in_grace_period; | |
273 | ||
274 | /* If we have no RPC client yet, create one. */ | |
275 | if ((clnt = nlm_bind_host(host)) == NULL) | |
276 | return -ENOLCK; | |
277 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
278 | ||
279 | /* Perform the RPC call. If an error occurs, try again */ | |
280 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
281 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
282 | switch (status) { | |
283 | case -EPROTONOSUPPORT: | |
284 | status = -EINVAL; | |
285 | break; | |
286 | case -ECONNREFUSED: | |
287 | case -ETIMEDOUT: | |
288 | case -ENOTCONN: | |
289 | nlm_rebind_host(host); | |
290 | status = -EAGAIN; | |
291 | break; | |
292 | case -ERESTARTSYS: | |
293 | return signalled () ? -EINTR : status; | |
294 | default: | |
295 | break; | |
296 | } | |
297 | break; | |
298 | } else | |
e8c5c045 | 299 | if (resp->status == nlm_lck_denied_grace_period) { |
1da177e4 LT |
300 | dprintk("lockd: server in grace period\n"); |
301 | if (argp->reclaim) { | |
302 | printk(KERN_WARNING | |
303 | "lockd: spurious grace period reject?!\n"); | |
304 | return -ENOLCK; | |
305 | } | |
306 | } else { | |
307 | if (!argp->reclaim) { | |
308 | /* We appear to be out of the grace period */ | |
309 | wake_up_all(&host->h_gracewait); | |
310 | } | |
311 | dprintk("lockd: server returns status %d\n", resp->status); | |
312 | return 0; /* Okay, call complete */ | |
313 | } | |
314 | ||
315 | in_grace_period: | |
316 | /* | |
317 | * The server has rebooted and appears to be in the grace | |
318 | * period during which locks are only allowed to be | |
319 | * reclaimed. | |
320 | * We can only back off and try again later. | |
321 | */ | |
322 | status = nlm_wait_on_grace(&host->h_gracewait); | |
323 | } while (status == 0); | |
324 | ||
325 | return status; | |
326 | } | |
327 | ||
328 | /* | |
329 | * Generic NLM call, async version. | |
330 | */ | |
dc9d8d04 | 331 | static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
332 | { |
333 | struct nlm_host *host = req->a_host; | |
334 | struct rpc_clnt *clnt; | |
dc9d8d04 TM |
335 | struct rpc_task_setup task_setup_data = { |
336 | .rpc_message = msg, | |
337 | .callback_ops = tk_ops, | |
338 | .callback_data = req, | |
339 | .flags = RPC_TASK_ASYNC, | |
340 | }; | |
1da177e4 LT |
341 | |
342 | dprintk("lockd: call procedure %d on %s (async)\n", | |
343 | (int)proc, host->h_name); | |
344 | ||
345 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
346 | clnt = nlm_bind_host(host); |
347 | if (clnt == NULL) | |
348 | goto out_err; | |
d4716624 | 349 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
dc9d8d04 | 350 | task_setup_data.rpc_client = clnt; |
1da177e4 | 351 | |
1da177e4 | 352 | /* bootstrap and kick off the async RPC call */ |
dc9d8d04 | 353 | return rpc_run_task(&task_setup_data); |
92737230 | 354 | out_err: |
a995e9eb | 355 | tk_ops->rpc_release(req); |
dc9d8d04 TM |
356 | return ERR_PTR(-ENOLCK); |
357 | } | |
358 | ||
359 | static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) | |
360 | { | |
361 | struct rpc_task *task; | |
362 | ||
363 | task = __nlm_async_call(req, proc, msg, tk_ops); | |
364 | if (IS_ERR(task)) | |
365 | return PTR_ERR(task); | |
366 | rpc_put_task(task); | |
367 | return 0; | |
1da177e4 LT |
368 | } |
369 | ||
dc9d8d04 TM |
370 | /* |
371 | * NLM asynchronous call. | |
372 | */ | |
d4716624 TM |
373 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
374 | { | |
375 | struct rpc_message msg = { | |
376 | .rpc_argp = &req->a_args, | |
377 | .rpc_resp = &req->a_res, | |
378 | }; | |
dc9d8d04 | 379 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
d4716624 TM |
380 | } |
381 | ||
382 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
383 | { | |
384 | struct rpc_message msg = { | |
385 | .rpc_argp = &req->a_res, | |
386 | }; | |
dc9d8d04 TM |
387 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
388 | } | |
389 | ||
390 | /* | |
391 | * NLM client asynchronous call. | |
392 | * | |
393 | * Note that although the calls are asynchronous, and are therefore | |
394 | * guaranteed to complete, we still always attempt to wait for | |
395 | * completion in order to be able to correctly track the lock | |
396 | * state. | |
397 | */ | |
d11d10cc | 398 | static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
dc9d8d04 TM |
399 | { |
400 | struct rpc_message msg = { | |
401 | .rpc_argp = &req->a_args, | |
402 | .rpc_resp = &req->a_res, | |
d11d10cc | 403 | .rpc_cred = cred, |
dc9d8d04 TM |
404 | }; |
405 | struct rpc_task *task; | |
406 | int err; | |
407 | ||
408 | task = __nlm_async_call(req, proc, &msg, tk_ops); | |
409 | if (IS_ERR(task)) | |
410 | return PTR_ERR(task); | |
411 | err = rpc_wait_for_completion_task(task); | |
412 | rpc_put_task(task); | |
413 | return err; | |
d4716624 TM |
414 | } |
415 | ||
1da177e4 LT |
416 | /* |
417 | * TEST for the presence of a conflicting lock | |
418 | */ | |
419 | static int | |
420 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
421 | { | |
422 | int status; | |
423 | ||
d11d10cc | 424 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST); |
1da177e4 | 425 | if (status < 0) |
92737230 | 426 | goto out; |
1da177e4 | 427 | |
92737230 | 428 | switch (req->a_res.status) { |
e8c5c045 | 429 | case nlm_granted: |
92737230 TM |
430 | fl->fl_type = F_UNLCK; |
431 | break; | |
e8c5c045 | 432 | case nlm_lck_denied: |
92737230 TM |
433 | /* |
434 | * Report the conflicting lock back to the application. | |
435 | */ | |
436 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
d67d1c7b | 437 | fl->fl_end = req->a_res.lock.fl.fl_end; |
92737230 TM |
438 | fl->fl_type = req->a_res.lock.fl.fl_type; |
439 | fl->fl_pid = 0; | |
440 | break; | |
441 | default: | |
442 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 443 | } |
92737230 TM |
444 | out: |
445 | nlm_release_call(req); | |
446 | return status; | |
1da177e4 LT |
447 | } |
448 | ||
449 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
450 | { | |
4c060b53 TM |
451 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
452 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
453 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
454 | } |
455 | ||
456 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
457 | { | |
4c060b53 | 458 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 459 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
460 | } |
461 | ||
6aed6285 | 462 | static const struct file_lock_operations nlmclnt_lock_ops = { |
1da177e4 LT |
463 | .fl_copy_lock = nlmclnt_locks_copy_lock, |
464 | .fl_release_private = nlmclnt_locks_release_private, | |
465 | }; | |
466 | ||
467 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
468 | { | |
469 | BUG_ON(fl->fl_ops != NULL); | |
470 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 471 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 472 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
473 | fl->fl_ops = &nlmclnt_lock_ops; |
474 | } | |
475 | ||
9b073574 | 476 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
477 | { |
478 | int res = 0; | |
479 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
480 | case FL_POSIX: | |
481 | res = posix_lock_file_wait(fl->fl_file, fl); | |
482 | break; | |
483 | case FL_FLOCK: | |
484 | res = flock_lock_file_wait(fl->fl_file, fl); | |
485 | break; | |
486 | default: | |
487 | BUG(); | |
488 | } | |
9b073574 | 489 | return res; |
1da177e4 LT |
490 | } |
491 | ||
492 | /* | |
493 | * LOCK: Try to create a lock | |
494 | * | |
495 | * Programmer Harassment Alert | |
496 | * | |
497 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
498 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
499 | * the lock could be granted. This way, our local process could hang | |
500 | * around forever waiting for the callback. | |
501 | * | |
502 | * Solution A: Implement busy-waiting | |
503 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
504 | * | |
505 | * For now I am implementing solution A, because I hate the idea of | |
506 | * re-implementing lockd for a third time in two months. The async | |
507 | * calls shouldn't be too hard to do, however. | |
508 | * | |
509 | * This is one of the lovely things about standards in the NFS area: | |
510 | * they're so soft and squishy you can't really blame HP for doing this. | |
511 | */ | |
512 | static int | |
513 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
514 | { | |
d11d10cc | 515 | struct rpc_cred *cred = nfs_file_cred(fl->fl_file); |
1da177e4 LT |
516 | struct nlm_host *host = req->a_host; |
517 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 518 | struct nlm_wait *block = NULL; |
01c3b861 | 519 | unsigned char fl_flags = fl->fl_flags; |
5f50c0c6 | 520 | unsigned char fl_type; |
3a649b88 | 521 | int status = -ENOLCK; |
1da177e4 | 522 | |
501c1ed3 | 523 | if (nsm_monitor(host) < 0) |
1da177e4 | 524 | goto out; |
6c9dc425 | 525 | req->a_args.state = nsm_local_state; |
501c1ed3 | 526 | |
01c3b861 TM |
527 | fl->fl_flags |= FL_ACCESS; |
528 | status = do_vfs_lock(fl); | |
4a9af59f | 529 | fl->fl_flags = fl_flags; |
01c3b861 TM |
530 | if (status < 0) |
531 | goto out; | |
1da177e4 | 532 | |
3a649b88 | 533 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 534 | again: |
5f50c0c6 TM |
535 | /* |
536 | * Initialise resp->status to a valid non-zero value, | |
537 | * since 0 == nlm_lck_granted | |
538 | */ | |
539 | resp->status = nlm_lck_blocked; | |
ecdbf769 | 540 | for(;;) { |
28df955a TM |
541 | /* Reboot protection */ |
542 | fl->fl_u.nfs_fl.state = host->h_state; | |
d11d10cc | 543 | status = nlmclnt_call(cred, req, NLMPROC_LOCK); |
ecdbf769 | 544 | if (status < 0) |
ecdbf769 | 545 | break; |
ecdbf769 | 546 | /* Did a reclaimer thread notify us of a server reboot? */ |
e8c5c045 | 547 | if (resp->status == nlm_lck_denied_grace_period) |
ecdbf769 | 548 | continue; |
e8c5c045 | 549 | if (resp->status != nlm_lck_blocked) |
ecdbf769 | 550 | break; |
3a649b88 TM |
551 | /* Wait on an NLM blocking lock */ |
552 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
3a649b88 | 553 | if (status < 0) |
5f50c0c6 | 554 | break; |
e8c5c045 | 555 | if (resp->status != nlm_lck_blocked) |
3a649b88 | 556 | break; |
ecdbf769 | 557 | } |
1da177e4 | 558 | |
5f50c0c6 TM |
559 | /* if we were interrupted while blocking, then cancel the lock request |
560 | * and exit | |
561 | */ | |
562 | if (resp->status == nlm_lck_blocked) { | |
563 | if (!req->a_args.block) | |
564 | goto out_unlock; | |
565 | if (nlmclnt_cancel(host, req->a_args.block, fl) == 0) | |
566 | goto out_unblock; | |
567 | } | |
568 | ||
e8c5c045 | 569 | if (resp->status == nlm_granted) { |
28df955a TM |
570 | down_read(&host->h_rwsem); |
571 | /* Check whether or not the server has rebooted */ | |
572 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
573 | up_read(&host->h_rwsem); | |
574 | goto again; | |
575 | } | |
4c060b53 | 576 | /* Ensure the resulting lock will get added to granted list */ |
4a9af59f | 577 | fl->fl_flags |= FL_SLEEP; |
9b073574 | 578 | if (do_vfs_lock(fl) < 0) |
8e24eea7 | 579 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__); |
28df955a | 580 | up_read(&host->h_rwsem); |
4a9af59f | 581 | fl->fl_flags = fl_flags; |
5f50c0c6 | 582 | status = 0; |
1da177e4 | 583 | } |
5f50c0c6 TM |
584 | if (status < 0) |
585 | goto out_unlock; | |
cc77b152 MS |
586 | /* |
587 | * EAGAIN doesn't make sense for sleeping locks, and in some | |
588 | * cases NLM_LCK_DENIED is returned for a permanent error. So | |
589 | * turn it into an ENOLCK. | |
590 | */ | |
591 | if (resp->status == nlm_lck_denied && (fl_flags & FL_SLEEP)) | |
592 | status = -ENOLCK; | |
593 | else | |
594 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 595 | out_unblock: |
3a649b88 | 596 | nlmclnt_finish_block(block); |
1da177e4 | 597 | out: |
92737230 | 598 | nlm_release_call(req); |
1da177e4 | 599 | return status; |
5f50c0c6 TM |
600 | out_unlock: |
601 | /* Fatal error: ensure that we remove the lock altogether */ | |
602 | dprintk("lockd: lock attempt ended in fatal error.\n" | |
603 | " Attempting to unlock.\n"); | |
604 | nlmclnt_finish_block(block); | |
605 | fl_type = fl->fl_type; | |
606 | fl->fl_type = F_UNLCK; | |
607 | down_read(&host->h_rwsem); | |
608 | do_vfs_lock(fl); | |
609 | up_read(&host->h_rwsem); | |
610 | fl->fl_type = fl_type; | |
611 | fl->fl_flags = fl_flags; | |
d11d10cc | 612 | nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); |
5f50c0c6 | 613 | return status; |
1da177e4 LT |
614 | } |
615 | ||
616 | /* | |
617 | * RECLAIM: Try to reclaim a lock | |
618 | */ | |
619 | int | |
620 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
621 | { | |
622 | struct nlm_rqst reqst, *req; | |
623 | int status; | |
624 | ||
625 | req = &reqst; | |
626 | memset(req, 0, sizeof(*req)); | |
627 | locks_init_lock(&req->a_args.lock.fl); | |
628 | locks_init_lock(&req->a_res.lock.fl); | |
629 | req->a_host = host; | |
630 | req->a_flags = 0; | |
631 | ||
632 | /* Set up the argument struct */ | |
633 | nlmclnt_setlockargs(req, fl); | |
634 | req->a_args.reclaim = 1; | |
635 | ||
d11d10cc TM |
636 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK); |
637 | if (status >= 0 && req->a_res.status == nlm_granted) | |
1da177e4 LT |
638 | return 0; |
639 | ||
640 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
641 | "(errno %d, status %d)\n", fl->fl_pid, | |
e8c5c045 | 642 | status, ntohl(req->a_res.status)); |
1da177e4 LT |
643 | |
644 | /* | |
645 | * FIXME: This is a serious failure. We can | |
646 | * | |
647 | * a. Ignore the problem | |
648 | * b. Send the owning process some signal (Linux doesn't have | |
649 | * SIGLOST, though...) | |
650 | * c. Retry the operation | |
651 | * | |
652 | * Until someone comes up with a simple implementation | |
653 | * for b or c, I'll choose option a. | |
654 | */ | |
655 | ||
656 | return -ENOLCK; | |
657 | } | |
658 | ||
659 | /* | |
660 | * UNLOCK: remove an existing lock | |
661 | */ | |
662 | static int | |
663 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
664 | { | |
28df955a | 665 | struct nlm_host *host = req->a_host; |
1da177e4 | 666 | struct nlm_res *resp = &req->a_res; |
4a9af59f TM |
667 | int status; |
668 | unsigned char fl_flags = fl->fl_flags; | |
1da177e4 | 669 | |
30f4e20a TM |
670 | /* |
671 | * Note: the server is supposed to either grant us the unlock | |
672 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
673 | * case, we want to unlock. | |
674 | */ | |
9b073574 | 675 | fl->fl_flags |= FL_EXISTS; |
28df955a | 676 | down_read(&host->h_rwsem); |
4a9af59f TM |
677 | status = do_vfs_lock(fl); |
678 | up_read(&host->h_rwsem); | |
679 | fl->fl_flags = fl_flags; | |
680 | if (status == -ENOENT) { | |
681 | status = 0; | |
9b073574 TM |
682 | goto out; |
683 | } | |
30f4e20a | 684 | |
dc9d8d04 | 685 | atomic_inc(&req->a_count); |
d11d10cc TM |
686 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
687 | NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 | 688 | if (status < 0) |
92737230 | 689 | goto out; |
1da177e4 | 690 | |
e8c5c045 | 691 | if (resp->status == nlm_granted) |
92737230 | 692 | goto out; |
1da177e4 | 693 | |
e8c5c045 | 694 | if (resp->status != nlm_lck_denied_nolocks) |
1da177e4 | 695 | printk("lockd: unexpected unlock status: %d\n", resp->status); |
1da177e4 | 696 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
697 | status = -ENOLCK; |
698 | out: | |
699 | nlm_release_call(req); | |
700 | return status; | |
1da177e4 LT |
701 | } |
702 | ||
963d8fe5 | 703 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 704 | { |
963d8fe5 | 705 | struct nlm_rqst *req = data; |
e8c5c045 | 706 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
707 | |
708 | if (RPC_ASSASSINATED(task)) | |
709 | goto die; | |
710 | ||
711 | if (task->tk_status < 0) { | |
712 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
713 | goto retry_rebind; | |
714 | } | |
715 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
716 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
717 | goto retry_unlock; | |
718 | } | |
719 | if (status != NLM_LCK_GRANTED) | |
720 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
721 | die: | |
1da177e4 LT |
722 | return; |
723 | retry_rebind: | |
a86dc496 | 724 | lock_kernel(); |
1da177e4 | 725 | nlm_rebind_host(req->a_host); |
a86dc496 | 726 | unlock_kernel(); |
1da177e4 LT |
727 | retry_unlock: |
728 | rpc_restart_call(task); | |
729 | } | |
730 | ||
963d8fe5 TM |
731 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
732 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 733 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
734 | }; |
735 | ||
1da177e4 LT |
736 | /* |
737 | * Cancel a blocked lock request. | |
738 | * We always use an async RPC call for this in order not to hang a | |
739 | * process that has been Ctrl-C'ed. | |
740 | */ | |
16fb2425 | 741 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
742 | { |
743 | struct nlm_rqst *req; | |
6b4b3a75 TM |
744 | int status; |
745 | ||
746 | dprintk("lockd: blocking lock attempt was interrupted by a signal.\n" | |
747 | " Attempting to cancel lock.\n"); | |
1da177e4 | 748 | |
92737230 | 749 | req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4 LT |
750 | if (!req) |
751 | return -ENOMEM; | |
1da177e4 LT |
752 | req->a_flags = RPC_TASK_ASYNC; |
753 | ||
754 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 755 | req->a_args.block = block; |
1da177e4 | 756 | |
6b4b3a75 | 757 | atomic_inc(&req->a_count); |
d11d10cc TM |
758 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
759 | NLMPROC_CANCEL, &nlmclnt_cancel_ops); | |
6b4b3a75 TM |
760 | if (status == 0 && req->a_res.status == nlm_lck_denied) |
761 | status = -ENOLCK; | |
762 | nlm_release_call(req); | |
763 | return status; | |
1da177e4 LT |
764 | } |
765 | ||
963d8fe5 | 766 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 767 | { |
963d8fe5 | 768 | struct nlm_rqst *req = data; |
e8c5c045 | 769 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
770 | |
771 | if (RPC_ASSASSINATED(task)) | |
772 | goto die; | |
773 | ||
774 | if (task->tk_status < 0) { | |
775 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
776 | task->tk_status); | |
777 | goto retry_cancel; | |
778 | } | |
779 | ||
c041b5ff | 780 | dprintk("lockd: cancel status %u (task %u)\n", |
e8c5c045 | 781 | status, task->tk_pid); |
1da177e4 | 782 | |
e8c5c045 | 783 | switch (status) { |
1da177e4 LT |
784 | case NLM_LCK_GRANTED: |
785 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 786 | case NLM_LCK_DENIED: |
1da177e4 LT |
787 | /* Everything's good */ |
788 | break; | |
789 | case NLM_LCK_DENIED_NOLOCKS: | |
790 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
791 | goto retry_cancel; | |
792 | default: | |
793 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
e8c5c045 | 794 | status); |
1da177e4 LT |
795 | } |
796 | ||
797 | die: | |
1da177e4 LT |
798 | return; |
799 | ||
800 | retry_cancel: | |
aaaa9942 TM |
801 | /* Don't ever retry more than 3 times */ |
802 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
803 | goto die; | |
a86dc496 | 804 | lock_kernel(); |
1da177e4 | 805 | nlm_rebind_host(req->a_host); |
a86dc496 | 806 | unlock_kernel(); |
1da177e4 LT |
807 | rpc_restart_call(task); |
808 | rpc_delay(task, 30 * HZ); | |
809 | } | |
810 | ||
963d8fe5 TM |
811 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
812 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 813 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
814 | }; |
815 | ||
1da177e4 LT |
816 | /* |
817 | * Convert an NLM status code to a generic kernel errno | |
818 | */ | |
819 | static int | |
e8c5c045 | 820 | nlm_stat_to_errno(__be32 status) |
1da177e4 | 821 | { |
e8c5c045 | 822 | switch(ntohl(status)) { |
1da177e4 LT |
823 | case NLM_LCK_GRANTED: |
824 | return 0; | |
825 | case NLM_LCK_DENIED: | |
826 | return -EAGAIN; | |
827 | case NLM_LCK_DENIED_NOLOCKS: | |
828 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
829 | return -ENOLCK; | |
830 | case NLM_LCK_BLOCKED: | |
831 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
832 | return -ENOLCK; | |
833 | #ifdef CONFIG_LOCKD_V4 | |
834 | case NLM_DEADLCK: | |
835 | return -EDEADLK; | |
836 | case NLM_ROFS: | |
837 | return -EROFS; | |
838 | case NLM_STALE_FH: | |
839 | return -ESTALE; | |
840 | case NLM_FBIG: | |
841 | return -EOVERFLOW; | |
842 | case NLM_FAILED: | |
843 | return -ENOLCK; | |
844 | #endif | |
845 | } | |
846 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
847 | return -ENOLCK; | |
848 | } |