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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/lockd/clntproc.c | |
4 | * | |
5 | * RPC procedures for the client side NLM implementation | |
6 | * | |
7 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | |
8 | */ | |
9 | ||
1da177e4 | 10 | #include <linux/module.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 | ||
9de3ec1d BC |
50 | static struct nlm_lockowner * |
51 | nlmclnt_get_lockowner(struct nlm_lockowner *lockowner) | |
1da177e4 | 52 | { |
431f125b | 53 | refcount_inc(&lockowner->count); |
1da177e4 LT |
54 | return lockowner; |
55 | } | |
56 | ||
291adeb2 | 57 | static void nlmclnt_put_lockowner(struct nlm_lockowner *lockowner) |
1da177e4 | 58 | { |
431f125b | 59 | if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) |
1da177e4 LT |
60 | return; |
61 | list_del(&lockowner->list); | |
62 | spin_unlock(&lockowner->host->h_lock); | |
8ea6ecc8 | 63 | nlmclnt_release_host(lockowner->host); |
1da177e4 LT |
64 | kfree(lockowner); |
65 | } | |
66 | ||
67 | static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) | |
68 | { | |
69 | struct nlm_lockowner *lockowner; | |
70 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
71 | if (lockowner->pid == pid) | |
72 | return -EBUSY; | |
73 | } | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) | |
78 | { | |
79 | uint32_t res; | |
80 | do { | |
81 | res = host->h_pidcount++; | |
82 | } while (nlm_pidbusy(host, res) < 0); | |
83 | return res; | |
84 | } | |
85 | ||
9de3ec1d | 86 | static struct nlm_lockowner *__nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner) |
1da177e4 LT |
87 | { |
88 | struct nlm_lockowner *lockowner; | |
89 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
90 | if (lockowner->owner != owner) | |
91 | continue; | |
9de3ec1d | 92 | return nlmclnt_get_lockowner(lockowner); |
1da177e4 LT |
93 | } |
94 | return NULL; | |
95 | } | |
96 | ||
9de3ec1d | 97 | static struct nlm_lockowner *nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner) |
1da177e4 LT |
98 | { |
99 | struct nlm_lockowner *res, *new = NULL; | |
100 | ||
101 | spin_lock(&host->h_lock); | |
9de3ec1d | 102 | res = __nlmclnt_find_lockowner(host, owner); |
1da177e4 LT |
103 | if (res == NULL) { |
104 | spin_unlock(&host->h_lock); | |
f52720ca | 105 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
1da177e4 | 106 | spin_lock(&host->h_lock); |
9de3ec1d | 107 | res = __nlmclnt_find_lockowner(host, owner); |
1da177e4 LT |
108 | if (res == NULL && new != NULL) { |
109 | res = new; | |
431f125b | 110 | refcount_set(&new->count, 1); |
1da177e4 LT |
111 | new->owner = owner; |
112 | new->pid = __nlm_alloc_pid(host); | |
113 | new->host = nlm_get_host(host); | |
114 | list_add(&new->list, &host->h_lockowners); | |
115 | new = NULL; | |
116 | } | |
117 | } | |
118 | spin_unlock(&host->h_lock); | |
f99d49ad | 119 | kfree(new); |
1da177e4 LT |
120 | return res; |
121 | } | |
122 | ||
123 | /* | |
124 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
125 | */ | |
126 | static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) | |
127 | { | |
128 | struct nlm_args *argp = &req->a_args; | |
129 | struct nlm_lock *lock = &argp->lock; | |
9a1b6bf8 | 130 | char *nodename = req->a_host->h_rpcclnt->cl_nodename; |
1da177e4 LT |
131 | |
132 | nlmclnt_next_cookie(&argp->cookie); | |
64bed6cb | 133 | memcpy(&lock->fh, NFS_FH(locks_inode(fl->fl_file)), sizeof(struct nfs_fh)); |
9a1b6bf8 | 134 | lock->caller = nodename; |
1da177e4 | 135 | lock->oh.data = req->a_owner; |
7bab377f TM |
136 | lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
137 | (unsigned int)fl->fl_u.nfs_fl.owner->pid, | |
9a1b6bf8 | 138 | nodename); |
7bab377f | 139 | lock->svid = fl->fl_u.nfs_fl.owner->pid; |
3a649b88 TM |
140 | lock->fl.fl_start = fl->fl_start; |
141 | lock->fl.fl_end = fl->fl_end; | |
142 | lock->fl.fl_type = fl->fl_type; | |
1da177e4 LT |
143 | } |
144 | ||
145 | static void nlmclnt_release_lockargs(struct nlm_rqst *req) | |
146 | { | |
26269348 | 147 | WARN_ON_ONCE(req->a_args.lock.fl.fl_ops != NULL); |
1da177e4 LT |
148 | } |
149 | ||
1093a60e CL |
150 | /** |
151 | * nlmclnt_proc - Perform a single client-side lock request | |
152 | * @host: address of a valid nlm_host context representing the NLM server | |
153 | * @cmd: fcntl-style file lock operation to perform | |
154 | * @fl: address of arguments for the lock operation | |
b1ece737 | 155 | * @data: address of data to be sent to callback operations |
1093a60e | 156 | * |
1da177e4 | 157 | */ |
b1ece737 | 158 | int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl, void *data) |
1da177e4 | 159 | { |
92737230 | 160 | struct nlm_rqst *call; |
1093a60e | 161 | int status; |
b1ece737 | 162 | const struct nlmclnt_operations *nlmclnt_ops = host->h_nlmclnt_ops; |
1da177e4 | 163 | |
92737230 TM |
164 | call = nlm_alloc_call(host); |
165 | if (call == NULL) | |
166 | return -ENOMEM; | |
1da177e4 | 167 | |
b1ece737 BC |
168 | if (nlmclnt_ops && nlmclnt_ops->nlmclnt_alloc_call) |
169 | nlmclnt_ops->nlmclnt_alloc_call(data); | |
170 | ||
92737230 | 171 | nlmclnt_locks_init_private(fl, host); |
bf884891 AV |
172 | if (!fl->fl_u.nfs_fl.owner) { |
173 | /* lockowner allocation has failed */ | |
174 | nlmclnt_release_call(call); | |
175 | return -ENOMEM; | |
176 | } | |
92737230 TM |
177 | /* Set up the argument struct */ |
178 | nlmclnt_setlockargs(call, fl); | |
b1ece737 | 179 | call->a_callback_data = data; |
1da177e4 | 180 | |
1da177e4 LT |
181 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { |
182 | if (fl->fl_type != F_UNLCK) { | |
183 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
184 | status = nlmclnt_lock(call, fl); | |
185 | } else | |
186 | status = nlmclnt_unlock(call, fl); | |
187 | } else if (IS_GETLK(cmd)) | |
188 | status = nlmclnt_test(call, fl); | |
189 | else | |
190 | status = -EINVAL; | |
92737230 TM |
191 | fl->fl_ops->fl_release_private(fl); |
192 | fl->fl_ops = NULL; | |
193 | ||
1da177e4 | 194 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
195 | return status; |
196 | } | |
1093a60e | 197 | EXPORT_SYMBOL_GPL(nlmclnt_proc); |
1da177e4 LT |
198 | |
199 | /* | |
200 | * Allocate an NLM RPC call struct | |
201 | */ | |
92737230 | 202 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
203 | { |
204 | struct nlm_rqst *call; | |
205 | ||
36943fa4 TM |
206 | for(;;) { |
207 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
208 | if (call != NULL) { | |
fbca30c5 | 209 | refcount_set(&call->a_count, 1); |
1da177e4 LT |
210 | locks_init_lock(&call->a_args.lock.fl); |
211 | locks_init_lock(&call->a_res.lock.fl); | |
446945ab | 212 | call->a_host = nlm_get_host(host); |
1da177e4 LT |
213 | return call; |
214 | } | |
36943fa4 TM |
215 | if (signalled()) |
216 | break; | |
92737230 | 217 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 218 | schedule_timeout_interruptible(5*HZ); |
1da177e4 LT |
219 | } |
220 | return NULL; | |
221 | } | |
222 | ||
7db836d4 | 223 | void nlmclnt_release_call(struct nlm_rqst *call) |
92737230 | 224 | { |
b1ece737 BC |
225 | const struct nlmclnt_operations *nlmclnt_ops = call->a_host->h_nlmclnt_ops; |
226 | ||
fbca30c5 | 227 | if (!refcount_dec_and_test(&call->a_count)) |
5e7f37a7 | 228 | return; |
b1ece737 BC |
229 | if (nlmclnt_ops && nlmclnt_ops->nlmclnt_release_call) |
230 | nlmclnt_ops->nlmclnt_release_call(call->a_callback_data); | |
8ea6ecc8 | 231 | nlmclnt_release_host(call->a_host); |
92737230 TM |
232 | nlmclnt_release_lockargs(call); |
233 | kfree(call); | |
234 | } | |
235 | ||
236 | static void nlmclnt_rpc_release(void *data) | |
237 | { | |
7db836d4 | 238 | nlmclnt_release_call(data); |
92737230 TM |
239 | } |
240 | ||
1da177e4 LT |
241 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
242 | { | |
243 | DEFINE_WAIT(wait); | |
244 | int status = -EINTR; | |
245 | ||
246 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
247 | if (!signalled ()) { | |
248 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 249 | try_to_freeze(); |
1da177e4 LT |
250 | if (!signalled ()) |
251 | status = 0; | |
252 | } | |
253 | finish_wait(queue, &wait); | |
254 | return status; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Generic NLM call | |
259 | */ | |
260 | static int | |
a52458b4 | 261 | nlmclnt_call(const struct cred *cred, struct nlm_rqst *req, u32 proc) |
1da177e4 LT |
262 | { |
263 | struct nlm_host *host = req->a_host; | |
264 | struct rpc_clnt *clnt; | |
265 | struct nlm_args *argp = &req->a_args; | |
266 | struct nlm_res *resp = &req->a_res; | |
267 | struct rpc_message msg = { | |
268 | .rpc_argp = argp, | |
269 | .rpc_resp = resp, | |
d11d10cc | 270 | .rpc_cred = cred, |
1da177e4 LT |
271 | }; |
272 | int status; | |
273 | ||
274 | dprintk("lockd: call procedure %d on %s\n", | |
275 | (int)proc, host->h_name); | |
276 | ||
277 | do { | |
278 | if (host->h_reclaiming && !argp->reclaim) | |
279 | goto in_grace_period; | |
280 | ||
281 | /* If we have no RPC client yet, create one. */ | |
282 | if ((clnt = nlm_bind_host(host)) == NULL) | |
283 | return -ENOLCK; | |
284 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
285 | ||
286 | /* Perform the RPC call. If an error occurs, try again */ | |
287 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
288 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
289 | switch (status) { | |
290 | case -EPROTONOSUPPORT: | |
291 | status = -EINVAL; | |
292 | break; | |
293 | case -ECONNREFUSED: | |
294 | case -ETIMEDOUT: | |
295 | case -ENOTCONN: | |
296 | nlm_rebind_host(host); | |
297 | status = -EAGAIN; | |
298 | break; | |
299 | case -ERESTARTSYS: | |
300 | return signalled () ? -EINTR : status; | |
301 | default: | |
302 | break; | |
303 | } | |
304 | break; | |
305 | } else | |
e8c5c045 | 306 | if (resp->status == nlm_lck_denied_grace_period) { |
1da177e4 LT |
307 | dprintk("lockd: server in grace period\n"); |
308 | if (argp->reclaim) { | |
309 | printk(KERN_WARNING | |
310 | "lockd: spurious grace period reject?!\n"); | |
311 | return -ENOLCK; | |
312 | } | |
313 | } else { | |
314 | if (!argp->reclaim) { | |
315 | /* We appear to be out of the grace period */ | |
316 | wake_up_all(&host->h_gracewait); | |
317 | } | |
82c2c8b8 VA |
318 | dprintk("lockd: server returns status %d\n", |
319 | ntohl(resp->status)); | |
1da177e4 LT |
320 | return 0; /* Okay, call complete */ |
321 | } | |
322 | ||
323 | in_grace_period: | |
324 | /* | |
325 | * The server has rebooted and appears to be in the grace | |
326 | * period during which locks are only allowed to be | |
327 | * reclaimed. | |
328 | * We can only back off and try again later. | |
329 | */ | |
330 | status = nlm_wait_on_grace(&host->h_gracewait); | |
331 | } while (status == 0); | |
332 | ||
333 | return status; | |
334 | } | |
335 | ||
336 | /* | |
337 | * Generic NLM call, async version. | |
338 | */ | |
dc9d8d04 | 339 | 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 |
340 | { |
341 | struct nlm_host *host = req->a_host; | |
342 | struct rpc_clnt *clnt; | |
dc9d8d04 TM |
343 | struct rpc_task_setup task_setup_data = { |
344 | .rpc_message = msg, | |
345 | .callback_ops = tk_ops, | |
346 | .callback_data = req, | |
347 | .flags = RPC_TASK_ASYNC, | |
348 | }; | |
1da177e4 LT |
349 | |
350 | dprintk("lockd: call procedure %d on %s (async)\n", | |
351 | (int)proc, host->h_name); | |
352 | ||
353 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
354 | clnt = nlm_bind_host(host); |
355 | if (clnt == NULL) | |
356 | goto out_err; | |
d4716624 | 357 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
dc9d8d04 | 358 | task_setup_data.rpc_client = clnt; |
1da177e4 | 359 | |
1da177e4 | 360 | /* bootstrap and kick off the async RPC call */ |
dc9d8d04 | 361 | return rpc_run_task(&task_setup_data); |
92737230 | 362 | out_err: |
a995e9eb | 363 | tk_ops->rpc_release(req); |
dc9d8d04 TM |
364 | return ERR_PTR(-ENOLCK); |
365 | } | |
366 | ||
367 | static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) | |
368 | { | |
369 | struct rpc_task *task; | |
370 | ||
371 | task = __nlm_async_call(req, proc, msg, tk_ops); | |
372 | if (IS_ERR(task)) | |
373 | return PTR_ERR(task); | |
374 | rpc_put_task(task); | |
375 | return 0; | |
1da177e4 LT |
376 | } |
377 | ||
dc9d8d04 TM |
378 | /* |
379 | * NLM asynchronous call. | |
380 | */ | |
d4716624 TM |
381 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
382 | { | |
383 | struct rpc_message msg = { | |
384 | .rpc_argp = &req->a_args, | |
385 | .rpc_resp = &req->a_res, | |
386 | }; | |
dc9d8d04 | 387 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
d4716624 TM |
388 | } |
389 | ||
390 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
391 | { | |
392 | struct rpc_message msg = { | |
393 | .rpc_argp = &req->a_res, | |
394 | }; | |
dc9d8d04 TM |
395 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
396 | } | |
397 | ||
398 | /* | |
399 | * NLM client asynchronous call. | |
400 | * | |
401 | * Note that although the calls are asynchronous, and are therefore | |
402 | * guaranteed to complete, we still always attempt to wait for | |
403 | * completion in order to be able to correctly track the lock | |
404 | * state. | |
405 | */ | |
a52458b4 | 406 | static int nlmclnt_async_call(const struct cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
dc9d8d04 TM |
407 | { |
408 | struct rpc_message msg = { | |
409 | .rpc_argp = &req->a_args, | |
410 | .rpc_resp = &req->a_res, | |
d11d10cc | 411 | .rpc_cred = cred, |
dc9d8d04 TM |
412 | }; |
413 | struct rpc_task *task; | |
414 | int err; | |
415 | ||
416 | task = __nlm_async_call(req, proc, &msg, tk_ops); | |
417 | if (IS_ERR(task)) | |
418 | return PTR_ERR(task); | |
419 | err = rpc_wait_for_completion_task(task); | |
420 | rpc_put_task(task); | |
421 | return err; | |
d4716624 TM |
422 | } |
423 | ||
1da177e4 LT |
424 | /* |
425 | * TEST for the presence of a conflicting lock | |
426 | */ | |
427 | static int | |
428 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
429 | { | |
430 | int status; | |
431 | ||
d11d10cc | 432 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST); |
1da177e4 | 433 | if (status < 0) |
92737230 | 434 | goto out; |
1da177e4 | 435 | |
92737230 | 436 | switch (req->a_res.status) { |
e8c5c045 | 437 | case nlm_granted: |
92737230 TM |
438 | fl->fl_type = F_UNLCK; |
439 | break; | |
e8c5c045 | 440 | case nlm_lck_denied: |
92737230 TM |
441 | /* |
442 | * Report the conflicting lock back to the application. | |
443 | */ | |
444 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
d67d1c7b | 445 | fl->fl_end = req->a_res.lock.fl.fl_end; |
92737230 | 446 | fl->fl_type = req->a_res.lock.fl.fl_type; |
b8eee0e9 | 447 | fl->fl_pid = -req->a_res.lock.fl.fl_pid; |
92737230 TM |
448 | break; |
449 | default: | |
450 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 451 | } |
92737230 | 452 | out: |
7db836d4 | 453 | nlmclnt_release_call(req); |
92737230 | 454 | return status; |
1da177e4 LT |
455 | } |
456 | ||
457 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
458 | { | |
63185942 | 459 | spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
4c060b53 | 460 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
9de3ec1d | 461 | new->fl_u.nfs_fl.owner = nlmclnt_get_lockowner(fl->fl_u.nfs_fl.owner); |
4c060b53 | 462 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); |
63185942 | 463 | spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
1da177e4 LT |
464 | } |
465 | ||
466 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
467 | { | |
63185942 | 468 | spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
4c060b53 | 469 | list_del(&fl->fl_u.nfs_fl.list); |
63185942 | 470 | spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
9de3ec1d | 471 | nlmclnt_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
472 | } |
473 | ||
6aed6285 | 474 | static const struct file_lock_operations nlmclnt_lock_ops = { |
1da177e4 LT |
475 | .fl_copy_lock = nlmclnt_locks_copy_lock, |
476 | .fl_release_private = nlmclnt_locks_release_private, | |
477 | }; | |
478 | ||
479 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
480 | { | |
1da177e4 | 481 | fl->fl_u.nfs_fl.state = 0; |
9de3ec1d | 482 | fl->fl_u.nfs_fl.owner = nlmclnt_find_lockowner(host, fl->fl_owner); |
4c060b53 | 483 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
484 | fl->fl_ops = &nlmclnt_lock_ops; |
485 | } | |
486 | ||
9b073574 | 487 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 | 488 | { |
4f656367 | 489 | return locks_lock_file_wait(fl->fl_file, fl); |
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 | { | |
a52458b4 | 515 | const struct 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: |
7db836d4 | 598 | nlmclnt_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 | |
f25cc71e TG |
620 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl, |
621 | struct nlm_rqst *req) | |
1da177e4 | 622 | { |
1da177e4 LT |
623 | int status; |
624 | ||
1da177e4 LT |
625 | memset(req, 0, sizeof(*req)); |
626 | locks_init_lock(&req->a_args.lock.fl); | |
627 | locks_init_lock(&req->a_res.lock.fl); | |
628 | req->a_host = host; | |
1da177e4 LT |
629 | |
630 | /* Set up the argument struct */ | |
631 | nlmclnt_setlockargs(req, fl); | |
632 | req->a_args.reclaim = 1; | |
633 | ||
d11d10cc TM |
634 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK); |
635 | if (status >= 0 && req->a_res.status == nlm_granted) | |
1da177e4 LT |
636 | return 0; |
637 | ||
638 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
639 | "(errno %d, status %d)\n", fl->fl_pid, | |
e8c5c045 | 640 | status, ntohl(req->a_res.status)); |
1da177e4 LT |
641 | |
642 | /* | |
643 | * FIXME: This is a serious failure. We can | |
644 | * | |
645 | * a. Ignore the problem | |
646 | * b. Send the owning process some signal (Linux doesn't have | |
647 | * SIGLOST, though...) | |
648 | * c. Retry the operation | |
649 | * | |
650 | * Until someone comes up with a simple implementation | |
651 | * for b or c, I'll choose option a. | |
652 | */ | |
653 | ||
654 | return -ENOLCK; | |
655 | } | |
656 | ||
657 | /* | |
658 | * UNLOCK: remove an existing lock | |
659 | */ | |
660 | static int | |
661 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
662 | { | |
28df955a | 663 | struct nlm_host *host = req->a_host; |
1da177e4 | 664 | struct nlm_res *resp = &req->a_res; |
4a9af59f TM |
665 | int status; |
666 | unsigned char fl_flags = fl->fl_flags; | |
1da177e4 | 667 | |
30f4e20a TM |
668 | /* |
669 | * Note: the server is supposed to either grant us the unlock | |
670 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
671 | * case, we want to unlock. | |
672 | */ | |
9b073574 | 673 | fl->fl_flags |= FL_EXISTS; |
28df955a | 674 | down_read(&host->h_rwsem); |
4a9af59f TM |
675 | status = do_vfs_lock(fl); |
676 | up_read(&host->h_rwsem); | |
677 | fl->fl_flags = fl_flags; | |
678 | if (status == -ENOENT) { | |
679 | status = 0; | |
9b073574 TM |
680 | goto out; |
681 | } | |
30f4e20a | 682 | |
fbca30c5 | 683 | refcount_inc(&req->a_count); |
d11d10cc TM |
684 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
685 | NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 | 686 | if (status < 0) |
92737230 | 687 | goto out; |
1da177e4 | 688 | |
e8c5c045 | 689 | if (resp->status == nlm_granted) |
92737230 | 690 | goto out; |
1da177e4 | 691 | |
e8c5c045 | 692 | if (resp->status != nlm_lck_denied_nolocks) |
82c2c8b8 VA |
693 | printk("lockd: unexpected unlock status: %d\n", |
694 | ntohl(resp->status)); | |
1da177e4 | 695 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
696 | status = -ENOLCK; |
697 | out: | |
7db836d4 | 698 | nlmclnt_release_call(req); |
92737230 | 699 | return status; |
1da177e4 LT |
700 | } |
701 | ||
b1ece737 BC |
702 | static void nlmclnt_unlock_prepare(struct rpc_task *task, void *data) |
703 | { | |
704 | struct nlm_rqst *req = data; | |
705 | const struct nlmclnt_operations *nlmclnt_ops = req->a_host->h_nlmclnt_ops; | |
706 | bool defer_call = false; | |
707 | ||
708 | if (nlmclnt_ops && nlmclnt_ops->nlmclnt_unlock_prepare) | |
709 | defer_call = nlmclnt_ops->nlmclnt_unlock_prepare(task, req->a_callback_data); | |
710 | ||
711 | if (!defer_call) | |
712 | rpc_call_start(task); | |
713 | } | |
714 | ||
963d8fe5 | 715 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 716 | { |
963d8fe5 | 717 | struct nlm_rqst *req = data; |
e8c5c045 | 718 | u32 status = ntohl(req->a_res.status); |
1da177e4 | 719 | |
ae67bd38 | 720 | if (RPC_SIGNALLED(task)) |
1da177e4 LT |
721 | goto die; |
722 | ||
723 | if (task->tk_status < 0) { | |
724 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
0b760113 TM |
725 | switch (task->tk_status) { |
726 | case -EACCES: | |
727 | case -EIO: | |
728 | goto die; | |
729 | default: | |
730 | goto retry_rebind; | |
731 | } | |
1da177e4 LT |
732 | } |
733 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
734 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
735 | goto retry_unlock; | |
736 | } | |
737 | if (status != NLM_LCK_GRANTED) | |
738 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
739 | die: | |
1da177e4 LT |
740 | return; |
741 | retry_rebind: | |
742 | nlm_rebind_host(req->a_host); | |
743 | retry_unlock: | |
744 | rpc_restart_call(task); | |
745 | } | |
746 | ||
963d8fe5 | 747 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
b1ece737 | 748 | .rpc_call_prepare = nlmclnt_unlock_prepare, |
963d8fe5 | 749 | .rpc_call_done = nlmclnt_unlock_callback, |
92737230 | 750 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
751 | }; |
752 | ||
1da177e4 LT |
753 | /* |
754 | * Cancel a blocked lock request. | |
755 | * We always use an async RPC call for this in order not to hang a | |
756 | * process that has been Ctrl-C'ed. | |
757 | */ | |
16fb2425 | 758 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
759 | { |
760 | struct nlm_rqst *req; | |
6b4b3a75 TM |
761 | int status; |
762 | ||
763 | dprintk("lockd: blocking lock attempt was interrupted by a signal.\n" | |
764 | " Attempting to cancel lock.\n"); | |
1da177e4 | 765 | |
446945ab | 766 | req = nlm_alloc_call(host); |
1da177e4 LT |
767 | if (!req) |
768 | return -ENOMEM; | |
1da177e4 LT |
769 | req->a_flags = RPC_TASK_ASYNC; |
770 | ||
771 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 772 | req->a_args.block = block; |
1da177e4 | 773 | |
fbca30c5 | 774 | refcount_inc(&req->a_count); |
d11d10cc TM |
775 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
776 | NLMPROC_CANCEL, &nlmclnt_cancel_ops); | |
6b4b3a75 TM |
777 | if (status == 0 && req->a_res.status == nlm_lck_denied) |
778 | status = -ENOLCK; | |
7db836d4 | 779 | nlmclnt_release_call(req); |
6b4b3a75 | 780 | return status; |
1da177e4 LT |
781 | } |
782 | ||
963d8fe5 | 783 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 784 | { |
963d8fe5 | 785 | struct nlm_rqst *req = data; |
e8c5c045 | 786 | u32 status = ntohl(req->a_res.status); |
1da177e4 | 787 | |
ae67bd38 | 788 | if (RPC_SIGNALLED(task)) |
1da177e4 LT |
789 | goto die; |
790 | ||
791 | if (task->tk_status < 0) { | |
792 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
793 | task->tk_status); | |
794 | goto retry_cancel; | |
795 | } | |
796 | ||
c041b5ff | 797 | dprintk("lockd: cancel status %u (task %u)\n", |
e8c5c045 | 798 | status, task->tk_pid); |
1da177e4 | 799 | |
e8c5c045 | 800 | switch (status) { |
1da177e4 LT |
801 | case NLM_LCK_GRANTED: |
802 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 803 | case NLM_LCK_DENIED: |
1da177e4 LT |
804 | /* Everything's good */ |
805 | break; | |
806 | case NLM_LCK_DENIED_NOLOCKS: | |
807 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
808 | goto retry_cancel; | |
809 | default: | |
810 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
e8c5c045 | 811 | status); |
1da177e4 LT |
812 | } |
813 | ||
814 | die: | |
1da177e4 LT |
815 | return; |
816 | ||
817 | retry_cancel: | |
aaaa9942 TM |
818 | /* Don't ever retry more than 3 times */ |
819 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
820 | goto die; | |
1da177e4 LT |
821 | nlm_rebind_host(req->a_host); |
822 | rpc_restart_call(task); | |
823 | rpc_delay(task, 30 * HZ); | |
824 | } | |
825 | ||
963d8fe5 TM |
826 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
827 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 828 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
829 | }; |
830 | ||
1da177e4 LT |
831 | /* |
832 | * Convert an NLM status code to a generic kernel errno | |
833 | */ | |
834 | static int | |
e8c5c045 | 835 | nlm_stat_to_errno(__be32 status) |
1da177e4 | 836 | { |
e8c5c045 | 837 | switch(ntohl(status)) { |
1da177e4 LT |
838 | case NLM_LCK_GRANTED: |
839 | return 0; | |
840 | case NLM_LCK_DENIED: | |
841 | return -EAGAIN; | |
842 | case NLM_LCK_DENIED_NOLOCKS: | |
843 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
844 | return -ENOLCK; | |
845 | case NLM_LCK_BLOCKED: | |
846 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
847 | return -ENOLCK; | |
848 | #ifdef CONFIG_LOCKD_V4 | |
849 | case NLM_DEADLCK: | |
850 | return -EDEADLK; | |
851 | case NLM_ROFS: | |
852 | return -EROFS; | |
853 | case NLM_STALE_FH: | |
854 | return -ESTALE; | |
855 | case NLM_FBIG: | |
856 | return -EOVERFLOW; | |
857 | case NLM_FAILED: | |
858 | return -ENOLCK; | |
859 | #endif | |
860 | } | |
82c2c8b8 VA |
861 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", |
862 | ntohl(status)); | |
1da177e4 LT |
863 | return -ENOLCK; |
864 | } |