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> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1da177e4 LT |
11 | #include <linux/types.h> |
12 | #include <linux/errno.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/nfs_fs.h> | |
15 | #include <linux/utsname.h> | |
7dfb7103 | 16 | #include <linux/freezer.h> |
1da177e4 LT |
17 | #include <linux/sunrpc/clnt.h> |
18 | #include <linux/sunrpc/svc.h> | |
19 | #include <linux/lockd/lockd.h> | |
1da177e4 LT |
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); | |
8ea6ecc8 | 61 | nlmclnt_release_host(lockowner->host); |
1da177e4 LT |
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; | |
9a1b6bf8 | 128 | char *nodename = req->a_host->h_rpcclnt->cl_nodename; |
1da177e4 LT |
129 | |
130 | nlmclnt_next_cookie(&argp->cookie); | |
496ad9aa | 131 | memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh)); |
9a1b6bf8 | 132 | lock->caller = 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, | |
9a1b6bf8 | 136 | 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 | { | |
26269348 | 145 | WARN_ON_ONCE(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 | |
92737230 TM |
160 | call = nlm_alloc_call(host); |
161 | if (call == NULL) | |
162 | return -ENOMEM; | |
1da177e4 | 163 | |
92737230 | 164 | nlmclnt_locks_init_private(fl, host); |
bf884891 AV |
165 | if (!fl->fl_u.nfs_fl.owner) { |
166 | /* lockowner allocation has failed */ | |
167 | nlmclnt_release_call(call); | |
168 | return -ENOMEM; | |
169 | } | |
92737230 TM |
170 | /* Set up the argument struct */ |
171 | nlmclnt_setlockargs(call, fl); | |
1da177e4 | 172 | |
1da177e4 LT |
173 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { |
174 | if (fl->fl_type != F_UNLCK) { | |
175 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
176 | status = nlmclnt_lock(call, fl); | |
177 | } else | |
178 | status = nlmclnt_unlock(call, fl); | |
179 | } else if (IS_GETLK(cmd)) | |
180 | status = nlmclnt_test(call, fl); | |
181 | else | |
182 | status = -EINVAL; | |
92737230 TM |
183 | fl->fl_ops->fl_release_private(fl); |
184 | fl->fl_ops = NULL; | |
185 | ||
1da177e4 | 186 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
187 | return status; |
188 | } | |
1093a60e | 189 | EXPORT_SYMBOL_GPL(nlmclnt_proc); |
1da177e4 LT |
190 | |
191 | /* | |
192 | * Allocate an NLM RPC call struct | |
193 | */ | |
92737230 | 194 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
195 | { |
196 | struct nlm_rqst *call; | |
197 | ||
36943fa4 TM |
198 | for(;;) { |
199 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
200 | if (call != NULL) { | |
5e7f37a7 | 201 | atomic_set(&call->a_count, 1); |
1da177e4 LT |
202 | locks_init_lock(&call->a_args.lock.fl); |
203 | locks_init_lock(&call->a_res.lock.fl); | |
446945ab | 204 | call->a_host = nlm_get_host(host); |
1da177e4 LT |
205 | return call; |
206 | } | |
36943fa4 TM |
207 | if (signalled()) |
208 | break; | |
92737230 | 209 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 210 | schedule_timeout_interruptible(5*HZ); |
1da177e4 LT |
211 | } |
212 | return NULL; | |
213 | } | |
214 | ||
7db836d4 | 215 | void nlmclnt_release_call(struct nlm_rqst *call) |
92737230 | 216 | { |
5e7f37a7 TM |
217 | if (!atomic_dec_and_test(&call->a_count)) |
218 | return; | |
8ea6ecc8 | 219 | nlmclnt_release_host(call->a_host); |
92737230 TM |
220 | nlmclnt_release_lockargs(call); |
221 | kfree(call); | |
222 | } | |
223 | ||
224 | static void nlmclnt_rpc_release(void *data) | |
225 | { | |
7db836d4 | 226 | nlmclnt_release_call(data); |
92737230 TM |
227 | } |
228 | ||
1da177e4 LT |
229 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
230 | { | |
231 | DEFINE_WAIT(wait); | |
232 | int status = -EINTR; | |
233 | ||
234 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
235 | if (!signalled ()) { | |
236 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 237 | try_to_freeze(); |
1da177e4 LT |
238 | if (!signalled ()) |
239 | status = 0; | |
240 | } | |
241 | finish_wait(queue, &wait); | |
242 | return status; | |
243 | } | |
244 | ||
245 | /* | |
246 | * Generic NLM call | |
247 | */ | |
248 | static int | |
d11d10cc | 249 | nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc) |
1da177e4 LT |
250 | { |
251 | struct nlm_host *host = req->a_host; | |
252 | struct rpc_clnt *clnt; | |
253 | struct nlm_args *argp = &req->a_args; | |
254 | struct nlm_res *resp = &req->a_res; | |
255 | struct rpc_message msg = { | |
256 | .rpc_argp = argp, | |
257 | .rpc_resp = resp, | |
d11d10cc | 258 | .rpc_cred = cred, |
1da177e4 LT |
259 | }; |
260 | int status; | |
261 | ||
262 | dprintk("lockd: call procedure %d on %s\n", | |
263 | (int)proc, host->h_name); | |
264 | ||
265 | do { | |
266 | if (host->h_reclaiming && !argp->reclaim) | |
267 | goto in_grace_period; | |
268 | ||
269 | /* If we have no RPC client yet, create one. */ | |
270 | if ((clnt = nlm_bind_host(host)) == NULL) | |
271 | return -ENOLCK; | |
272 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
273 | ||
274 | /* Perform the RPC call. If an error occurs, try again */ | |
275 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
276 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
277 | switch (status) { | |
278 | case -EPROTONOSUPPORT: | |
279 | status = -EINVAL; | |
280 | break; | |
281 | case -ECONNREFUSED: | |
282 | case -ETIMEDOUT: | |
283 | case -ENOTCONN: | |
284 | nlm_rebind_host(host); | |
285 | status = -EAGAIN; | |
286 | break; | |
287 | case -ERESTARTSYS: | |
288 | return signalled () ? -EINTR : status; | |
289 | default: | |
290 | break; | |
291 | } | |
292 | break; | |
293 | } else | |
e8c5c045 | 294 | if (resp->status == nlm_lck_denied_grace_period) { |
1da177e4 LT |
295 | dprintk("lockd: server in grace period\n"); |
296 | if (argp->reclaim) { | |
297 | printk(KERN_WARNING | |
298 | "lockd: spurious grace period reject?!\n"); | |
299 | return -ENOLCK; | |
300 | } | |
301 | } else { | |
302 | if (!argp->reclaim) { | |
303 | /* We appear to be out of the grace period */ | |
304 | wake_up_all(&host->h_gracewait); | |
305 | } | |
82c2c8b8 VA |
306 | dprintk("lockd: server returns status %d\n", |
307 | ntohl(resp->status)); | |
1da177e4 LT |
308 | return 0; /* Okay, call complete */ |
309 | } | |
310 | ||
311 | in_grace_period: | |
312 | /* | |
313 | * The server has rebooted and appears to be in the grace | |
314 | * period during which locks are only allowed to be | |
315 | * reclaimed. | |
316 | * We can only back off and try again later. | |
317 | */ | |
318 | status = nlm_wait_on_grace(&host->h_gracewait); | |
319 | } while (status == 0); | |
320 | ||
321 | return status; | |
322 | } | |
323 | ||
324 | /* | |
325 | * Generic NLM call, async version. | |
326 | */ | |
dc9d8d04 | 327 | 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 |
328 | { |
329 | struct nlm_host *host = req->a_host; | |
330 | struct rpc_clnt *clnt; | |
dc9d8d04 TM |
331 | struct rpc_task_setup task_setup_data = { |
332 | .rpc_message = msg, | |
333 | .callback_ops = tk_ops, | |
334 | .callback_data = req, | |
335 | .flags = RPC_TASK_ASYNC, | |
336 | }; | |
1da177e4 LT |
337 | |
338 | dprintk("lockd: call procedure %d on %s (async)\n", | |
339 | (int)proc, host->h_name); | |
340 | ||
341 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
342 | clnt = nlm_bind_host(host); |
343 | if (clnt == NULL) | |
344 | goto out_err; | |
d4716624 | 345 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
dc9d8d04 | 346 | task_setup_data.rpc_client = clnt; |
1da177e4 | 347 | |
1da177e4 | 348 | /* bootstrap and kick off the async RPC call */ |
dc9d8d04 | 349 | return rpc_run_task(&task_setup_data); |
92737230 | 350 | out_err: |
a995e9eb | 351 | tk_ops->rpc_release(req); |
dc9d8d04 TM |
352 | return ERR_PTR(-ENOLCK); |
353 | } | |
354 | ||
355 | static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) | |
356 | { | |
357 | struct rpc_task *task; | |
358 | ||
359 | task = __nlm_async_call(req, proc, msg, tk_ops); | |
360 | if (IS_ERR(task)) | |
361 | return PTR_ERR(task); | |
362 | rpc_put_task(task); | |
363 | return 0; | |
1da177e4 LT |
364 | } |
365 | ||
dc9d8d04 TM |
366 | /* |
367 | * NLM asynchronous call. | |
368 | */ | |
d4716624 TM |
369 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
370 | { | |
371 | struct rpc_message msg = { | |
372 | .rpc_argp = &req->a_args, | |
373 | .rpc_resp = &req->a_res, | |
374 | }; | |
dc9d8d04 | 375 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
d4716624 TM |
376 | } |
377 | ||
378 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
379 | { | |
380 | struct rpc_message msg = { | |
381 | .rpc_argp = &req->a_res, | |
382 | }; | |
dc9d8d04 TM |
383 | return nlm_do_async_call(req, proc, &msg, tk_ops); |
384 | } | |
385 | ||
386 | /* | |
387 | * NLM client asynchronous call. | |
388 | * | |
389 | * Note that although the calls are asynchronous, and are therefore | |
390 | * guaranteed to complete, we still always attempt to wait for | |
391 | * completion in order to be able to correctly track the lock | |
392 | * state. | |
393 | */ | |
d11d10cc | 394 | static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
dc9d8d04 TM |
395 | { |
396 | struct rpc_message msg = { | |
397 | .rpc_argp = &req->a_args, | |
398 | .rpc_resp = &req->a_res, | |
d11d10cc | 399 | .rpc_cred = cred, |
dc9d8d04 TM |
400 | }; |
401 | struct rpc_task *task; | |
402 | int err; | |
403 | ||
404 | task = __nlm_async_call(req, proc, &msg, tk_ops); | |
405 | if (IS_ERR(task)) | |
406 | return PTR_ERR(task); | |
407 | err = rpc_wait_for_completion_task(task); | |
408 | rpc_put_task(task); | |
409 | return err; | |
d4716624 TM |
410 | } |
411 | ||
1da177e4 LT |
412 | /* |
413 | * TEST for the presence of a conflicting lock | |
414 | */ | |
415 | static int | |
416 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
417 | { | |
418 | int status; | |
419 | ||
d11d10cc | 420 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST); |
1da177e4 | 421 | if (status < 0) |
92737230 | 422 | goto out; |
1da177e4 | 423 | |
92737230 | 424 | switch (req->a_res.status) { |
e8c5c045 | 425 | case nlm_granted: |
92737230 TM |
426 | fl->fl_type = F_UNLCK; |
427 | break; | |
e8c5c045 | 428 | case nlm_lck_denied: |
92737230 TM |
429 | /* |
430 | * Report the conflicting lock back to the application. | |
431 | */ | |
432 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
d67d1c7b | 433 | fl->fl_end = req->a_res.lock.fl.fl_end; |
92737230 TM |
434 | fl->fl_type = req->a_res.lock.fl.fl_type; |
435 | fl->fl_pid = 0; | |
436 | break; | |
437 | default: | |
438 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 439 | } |
92737230 | 440 | out: |
7db836d4 | 441 | nlmclnt_release_call(req); |
92737230 | 442 | return status; |
1da177e4 LT |
443 | } |
444 | ||
445 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
446 | { | |
63185942 | 447 | spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
4c060b53 TM |
448 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
449 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
450 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
63185942 | 451 | spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
1da177e4 LT |
452 | } |
453 | ||
454 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
455 | { | |
63185942 | 456 | spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
4c060b53 | 457 | list_del(&fl->fl_u.nfs_fl.list); |
63185942 | 458 | spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
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 | { | |
1da177e4 | 469 | fl->fl_u.nfs_fl.state = 0; |
1da177e4 | 470 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 471 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
472 | fl->fl_ops = &nlmclnt_lock_ops; |
473 | } | |
474 | ||
9b073574 | 475 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
476 | { |
477 | int res = 0; | |
478 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
479 | case FL_POSIX: | |
480 | res = posix_lock_file_wait(fl->fl_file, fl); | |
481 | break; | |
482 | case FL_FLOCK: | |
483 | res = flock_lock_file_wait(fl->fl_file, fl); | |
484 | break; | |
485 | default: | |
486 | BUG(); | |
487 | } | |
9b073574 | 488 | return res; |
1da177e4 LT |
489 | } |
490 | ||
491 | /* | |
492 | * LOCK: Try to create a lock | |
493 | * | |
494 | * Programmer Harassment Alert | |
495 | * | |
496 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
497 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
498 | * the lock could be granted. This way, our local process could hang | |
499 | * around forever waiting for the callback. | |
500 | * | |
501 | * Solution A: Implement busy-waiting | |
502 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
503 | * | |
504 | * For now I am implementing solution A, because I hate the idea of | |
505 | * re-implementing lockd for a third time in two months. The async | |
506 | * calls shouldn't be too hard to do, however. | |
507 | * | |
508 | * This is one of the lovely things about standards in the NFS area: | |
509 | * they're so soft and squishy you can't really blame HP for doing this. | |
510 | */ | |
511 | static int | |
512 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
513 | { | |
d11d10cc | 514 | struct rpc_cred *cred = nfs_file_cred(fl->fl_file); |
1da177e4 LT |
515 | struct nlm_host *host = req->a_host; |
516 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 517 | struct nlm_wait *block = NULL; |
01c3b861 | 518 | unsigned char fl_flags = fl->fl_flags; |
5f50c0c6 | 519 | unsigned char fl_type; |
3a649b88 | 520 | int status = -ENOLCK; |
1da177e4 | 521 | |
501c1ed3 | 522 | if (nsm_monitor(host) < 0) |
1da177e4 | 523 | goto out; |
6c9dc425 | 524 | req->a_args.state = nsm_local_state; |
501c1ed3 | 525 | |
01c3b861 TM |
526 | fl->fl_flags |= FL_ACCESS; |
527 | status = do_vfs_lock(fl); | |
4a9af59f | 528 | fl->fl_flags = fl_flags; |
01c3b861 TM |
529 | if (status < 0) |
530 | goto out; | |
1da177e4 | 531 | |
3a649b88 | 532 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 533 | again: |
5f50c0c6 TM |
534 | /* |
535 | * Initialise resp->status to a valid non-zero value, | |
536 | * since 0 == nlm_lck_granted | |
537 | */ | |
538 | resp->status = nlm_lck_blocked; | |
ecdbf769 | 539 | for(;;) { |
28df955a TM |
540 | /* Reboot protection */ |
541 | fl->fl_u.nfs_fl.state = host->h_state; | |
d11d10cc | 542 | status = nlmclnt_call(cred, req, NLMPROC_LOCK); |
ecdbf769 | 543 | if (status < 0) |
ecdbf769 | 544 | break; |
ecdbf769 | 545 | /* Did a reclaimer thread notify us of a server reboot? */ |
e8c5c045 | 546 | if (resp->status == nlm_lck_denied_grace_period) |
ecdbf769 | 547 | continue; |
e8c5c045 | 548 | if (resp->status != nlm_lck_blocked) |
ecdbf769 | 549 | break; |
3a649b88 TM |
550 | /* Wait on an NLM blocking lock */ |
551 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
3a649b88 | 552 | if (status < 0) |
5f50c0c6 | 553 | break; |
e8c5c045 | 554 | if (resp->status != nlm_lck_blocked) |
3a649b88 | 555 | break; |
ecdbf769 | 556 | } |
1da177e4 | 557 | |
5f50c0c6 TM |
558 | /* if we were interrupted while blocking, then cancel the lock request |
559 | * and exit | |
560 | */ | |
561 | if (resp->status == nlm_lck_blocked) { | |
562 | if (!req->a_args.block) | |
563 | goto out_unlock; | |
564 | if (nlmclnt_cancel(host, req->a_args.block, fl) == 0) | |
565 | goto out_unblock; | |
566 | } | |
567 | ||
e8c5c045 | 568 | if (resp->status == nlm_granted) { |
28df955a TM |
569 | down_read(&host->h_rwsem); |
570 | /* Check whether or not the server has rebooted */ | |
571 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
572 | up_read(&host->h_rwsem); | |
573 | goto again; | |
574 | } | |
4c060b53 | 575 | /* Ensure the resulting lock will get added to granted list */ |
4a9af59f | 576 | fl->fl_flags |= FL_SLEEP; |
9b073574 | 577 | if (do_vfs_lock(fl) < 0) |
8e24eea7 | 578 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__); |
28df955a | 579 | up_read(&host->h_rwsem); |
4a9af59f | 580 | fl->fl_flags = fl_flags; |
5f50c0c6 | 581 | status = 0; |
1da177e4 | 582 | } |
5f50c0c6 TM |
583 | if (status < 0) |
584 | goto out_unlock; | |
cc77b152 MS |
585 | /* |
586 | * EAGAIN doesn't make sense for sleeping locks, and in some | |
587 | * cases NLM_LCK_DENIED is returned for a permanent error. So | |
588 | * turn it into an ENOLCK. | |
589 | */ | |
590 | if (resp->status == nlm_lck_denied && (fl_flags & FL_SLEEP)) | |
591 | status = -ENOLCK; | |
592 | else | |
593 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 594 | out_unblock: |
3a649b88 | 595 | nlmclnt_finish_block(block); |
1da177e4 | 596 | out: |
7db836d4 | 597 | nlmclnt_release_call(req); |
1da177e4 | 598 | return status; |
5f50c0c6 TM |
599 | out_unlock: |
600 | /* Fatal error: ensure that we remove the lock altogether */ | |
601 | dprintk("lockd: lock attempt ended in fatal error.\n" | |
602 | " Attempting to unlock.\n"); | |
603 | nlmclnt_finish_block(block); | |
604 | fl_type = fl->fl_type; | |
605 | fl->fl_type = F_UNLCK; | |
606 | down_read(&host->h_rwsem); | |
607 | do_vfs_lock(fl); | |
608 | up_read(&host->h_rwsem); | |
609 | fl->fl_type = fl_type; | |
610 | fl->fl_flags = fl_flags; | |
d11d10cc | 611 | nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); |
5f50c0c6 | 612 | return status; |
1da177e4 LT |
613 | } |
614 | ||
615 | /* | |
616 | * RECLAIM: Try to reclaim a lock | |
617 | */ | |
618 | int | |
f25cc71e TG |
619 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl, |
620 | struct nlm_rqst *req) | |
1da177e4 | 621 | { |
1da177e4 LT |
622 | int status; |
623 | ||
1da177e4 LT |
624 | memset(req, 0, sizeof(*req)); |
625 | locks_init_lock(&req->a_args.lock.fl); | |
626 | locks_init_lock(&req->a_res.lock.fl); | |
627 | req->a_host = host; | |
1da177e4 LT |
628 | |
629 | /* Set up the argument struct */ | |
630 | nlmclnt_setlockargs(req, fl); | |
631 | req->a_args.reclaim = 1; | |
632 | ||
d11d10cc TM |
633 | status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK); |
634 | if (status >= 0 && req->a_res.status == nlm_granted) | |
1da177e4 LT |
635 | return 0; |
636 | ||
637 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
638 | "(errno %d, status %d)\n", fl->fl_pid, | |
e8c5c045 | 639 | status, ntohl(req->a_res.status)); |
1da177e4 LT |
640 | |
641 | /* | |
642 | * FIXME: This is a serious failure. We can | |
643 | * | |
644 | * a. Ignore the problem | |
645 | * b. Send the owning process some signal (Linux doesn't have | |
646 | * SIGLOST, though...) | |
647 | * c. Retry the operation | |
648 | * | |
649 | * Until someone comes up with a simple implementation | |
650 | * for b or c, I'll choose option a. | |
651 | */ | |
652 | ||
653 | return -ENOLCK; | |
654 | } | |
655 | ||
656 | /* | |
657 | * UNLOCK: remove an existing lock | |
658 | */ | |
659 | static int | |
660 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
661 | { | |
28df955a | 662 | struct nlm_host *host = req->a_host; |
1da177e4 | 663 | struct nlm_res *resp = &req->a_res; |
4a9af59f TM |
664 | int status; |
665 | unsigned char fl_flags = fl->fl_flags; | |
1da177e4 | 666 | |
30f4e20a TM |
667 | /* |
668 | * Note: the server is supposed to either grant us the unlock | |
669 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
670 | * case, we want to unlock. | |
671 | */ | |
9b073574 | 672 | fl->fl_flags |= FL_EXISTS; |
28df955a | 673 | down_read(&host->h_rwsem); |
4a9af59f TM |
674 | status = do_vfs_lock(fl); |
675 | up_read(&host->h_rwsem); | |
676 | fl->fl_flags = fl_flags; | |
677 | if (status == -ENOENT) { | |
678 | status = 0; | |
9b073574 TM |
679 | goto out; |
680 | } | |
30f4e20a | 681 | |
dc9d8d04 | 682 | atomic_inc(&req->a_count); |
d11d10cc TM |
683 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
684 | NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 | 685 | if (status < 0) |
92737230 | 686 | goto out; |
1da177e4 | 687 | |
e8c5c045 | 688 | if (resp->status == nlm_granted) |
92737230 | 689 | goto out; |
1da177e4 | 690 | |
e8c5c045 | 691 | if (resp->status != nlm_lck_denied_nolocks) |
82c2c8b8 VA |
692 | printk("lockd: unexpected unlock status: %d\n", |
693 | ntohl(resp->status)); | |
1da177e4 | 694 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
695 | status = -ENOLCK; |
696 | out: | |
7db836d4 | 697 | nlmclnt_release_call(req); |
92737230 | 698 | return status; |
1da177e4 LT |
699 | } |
700 | ||
963d8fe5 | 701 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 702 | { |
963d8fe5 | 703 | struct nlm_rqst *req = data; |
e8c5c045 | 704 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
705 | |
706 | if (RPC_ASSASSINATED(task)) | |
707 | goto die; | |
708 | ||
709 | if (task->tk_status < 0) { | |
710 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
0b760113 TM |
711 | switch (task->tk_status) { |
712 | case -EACCES: | |
713 | case -EIO: | |
714 | goto die; | |
715 | default: | |
716 | goto retry_rebind; | |
717 | } | |
1da177e4 LT |
718 | } |
719 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
720 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
721 | goto retry_unlock; | |
722 | } | |
723 | if (status != NLM_LCK_GRANTED) | |
724 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
725 | die: | |
1da177e4 LT |
726 | return; |
727 | retry_rebind: | |
728 | nlm_rebind_host(req->a_host); | |
729 | retry_unlock: | |
730 | rpc_restart_call(task); | |
731 | } | |
732 | ||
963d8fe5 TM |
733 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
734 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 735 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
736 | }; |
737 | ||
1da177e4 LT |
738 | /* |
739 | * Cancel a blocked lock request. | |
740 | * We always use an async RPC call for this in order not to hang a | |
741 | * process that has been Ctrl-C'ed. | |
742 | */ | |
16fb2425 | 743 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
744 | { |
745 | struct nlm_rqst *req; | |
6b4b3a75 TM |
746 | int status; |
747 | ||
748 | dprintk("lockd: blocking lock attempt was interrupted by a signal.\n" | |
749 | " Attempting to cancel lock.\n"); | |
1da177e4 | 750 | |
446945ab | 751 | req = nlm_alloc_call(host); |
1da177e4 LT |
752 | if (!req) |
753 | return -ENOMEM; | |
1da177e4 LT |
754 | req->a_flags = RPC_TASK_ASYNC; |
755 | ||
756 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 757 | req->a_args.block = block; |
1da177e4 | 758 | |
6b4b3a75 | 759 | atomic_inc(&req->a_count); |
d11d10cc TM |
760 | status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, |
761 | NLMPROC_CANCEL, &nlmclnt_cancel_ops); | |
6b4b3a75 TM |
762 | if (status == 0 && req->a_res.status == nlm_lck_denied) |
763 | status = -ENOLCK; | |
7db836d4 | 764 | nlmclnt_release_call(req); |
6b4b3a75 | 765 | return status; |
1da177e4 LT |
766 | } |
767 | ||
963d8fe5 | 768 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 769 | { |
963d8fe5 | 770 | struct nlm_rqst *req = data; |
e8c5c045 | 771 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
772 | |
773 | if (RPC_ASSASSINATED(task)) | |
774 | goto die; | |
775 | ||
776 | if (task->tk_status < 0) { | |
777 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
778 | task->tk_status); | |
779 | goto retry_cancel; | |
780 | } | |
781 | ||
c041b5ff | 782 | dprintk("lockd: cancel status %u (task %u)\n", |
e8c5c045 | 783 | status, task->tk_pid); |
1da177e4 | 784 | |
e8c5c045 | 785 | switch (status) { |
1da177e4 LT |
786 | case NLM_LCK_GRANTED: |
787 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 788 | case NLM_LCK_DENIED: |
1da177e4 LT |
789 | /* Everything's good */ |
790 | break; | |
791 | case NLM_LCK_DENIED_NOLOCKS: | |
792 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
793 | goto retry_cancel; | |
794 | default: | |
795 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
e8c5c045 | 796 | status); |
1da177e4 LT |
797 | } |
798 | ||
799 | die: | |
1da177e4 LT |
800 | return; |
801 | ||
802 | retry_cancel: | |
aaaa9942 TM |
803 | /* Don't ever retry more than 3 times */ |
804 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
805 | goto die; | |
1da177e4 LT |
806 | nlm_rebind_host(req->a_host); |
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 | } | |
82c2c8b8 VA |
846 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", |
847 | ntohl(status)); | |
1da177e4 LT |
848 | return -ENOLCK; |
849 | } |