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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 LT |
9 | #include <linux/module.h> |
10 | #include <linux/types.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/fs.h> | |
13 | #include <linux/nfs_fs.h> | |
14 | #include <linux/utsname.h> | |
7dfb7103 | 15 | #include <linux/freezer.h> |
1da177e4 LT |
16 | #include <linux/sunrpc/clnt.h> |
17 | #include <linux/sunrpc/svc.h> | |
18 | #include <linux/lockd/lockd.h> | |
19 | #include <linux/lockd/sm_inter.h> | |
20 | ||
21 | #define NLMDBG_FACILITY NLMDBG_CLIENT | |
22 | #define NLMCLNT_GRACE_WAIT (5*HZ) | |
ecdbf769 | 23 | #define NLMCLNT_POLL_TIMEOUT (30*HZ) |
aaaa9942 | 24 | #define NLMCLNT_MAX_RETRIES 3 |
1da177e4 LT |
25 | |
26 | static int nlmclnt_test(struct nlm_rqst *, struct file_lock *); | |
27 | static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *); | |
28 | static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *); | |
e8c5c045 | 29 | static int nlm_stat_to_errno(__be32 stat); |
1da177e4 | 30 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); |
16fb2425 | 31 | static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
1da177e4 | 32 | |
963d8fe5 TM |
33 | static const struct rpc_call_ops nlmclnt_unlock_ops; |
34 | static const struct rpc_call_ops nlmclnt_cancel_ops; | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * Cookie counter for NLM requests | |
38 | */ | |
031d869d | 39 | static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
1da177e4 | 40 | |
031d869d | 41 | void nlmclnt_next_cookie(struct nlm_cookie *c) |
1da177e4 | 42 | { |
031d869d OK |
43 | u32 cookie = atomic_inc_return(&nlm_cookie); |
44 | ||
45 | memcpy(c->data, &cookie, 4); | |
1da177e4 | 46 | c->len=4; |
1da177e4 LT |
47 | } |
48 | ||
49 | static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner) | |
50 | { | |
51 | atomic_inc(&lockowner->count); | |
52 | return lockowner; | |
53 | } | |
54 | ||
55 | static void nlm_put_lockowner(struct nlm_lockowner *lockowner) | |
56 | { | |
57 | if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) | |
58 | return; | |
59 | list_del(&lockowner->list); | |
60 | spin_unlock(&lockowner->host->h_lock); | |
61 | nlm_release_host(lockowner->host); | |
62 | kfree(lockowner); | |
63 | } | |
64 | ||
65 | static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) | |
66 | { | |
67 | struct nlm_lockowner *lockowner; | |
68 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
69 | if (lockowner->pid == pid) | |
70 | return -EBUSY; | |
71 | } | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) | |
76 | { | |
77 | uint32_t res; | |
78 | do { | |
79 | res = host->h_pidcount++; | |
80 | } while (nlm_pidbusy(host, res) < 0); | |
81 | return res; | |
82 | } | |
83 | ||
84 | static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
85 | { | |
86 | struct nlm_lockowner *lockowner; | |
87 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
88 | if (lockowner->owner != owner) | |
89 | continue; | |
90 | return nlm_get_lockowner(lockowner); | |
91 | } | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
96 | { | |
97 | struct nlm_lockowner *res, *new = NULL; | |
98 | ||
99 | spin_lock(&host->h_lock); | |
100 | res = __nlm_find_lockowner(host, owner); | |
101 | if (res == NULL) { | |
102 | spin_unlock(&host->h_lock); | |
f52720ca | 103 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
1da177e4 LT |
104 | spin_lock(&host->h_lock); |
105 | res = __nlm_find_lockowner(host, owner); | |
106 | if (res == NULL && new != NULL) { | |
107 | res = new; | |
108 | atomic_set(&new->count, 1); | |
109 | new->owner = owner; | |
110 | new->pid = __nlm_alloc_pid(host); | |
111 | new->host = nlm_get_host(host); | |
112 | list_add(&new->list, &host->h_lockowners); | |
113 | new = NULL; | |
114 | } | |
115 | } | |
116 | spin_unlock(&host->h_lock); | |
f99d49ad | 117 | kfree(new); |
1da177e4 LT |
118 | return res; |
119 | } | |
120 | ||
121 | /* | |
122 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
123 | */ | |
124 | static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) | |
125 | { | |
126 | struct nlm_args *argp = &req->a_args; | |
127 | struct nlm_lock *lock = &argp->lock; | |
128 | ||
129 | nlmclnt_next_cookie(&argp->cookie); | |
130 | argp->state = nsm_local_state; | |
225a719f | 131 | memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh)); |
e9ff3990 | 132 | lock->caller = utsname()->nodename; |
1da177e4 | 133 | lock->oh.data = req->a_owner; |
7bab377f TM |
134 | lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
135 | (unsigned int)fl->fl_u.nfs_fl.owner->pid, | |
e9ff3990 | 136 | utsname()->nodename); |
7bab377f | 137 | lock->svid = fl->fl_u.nfs_fl.owner->pid; |
3a649b88 TM |
138 | lock->fl.fl_start = fl->fl_start; |
139 | lock->fl.fl_end = fl->fl_end; | |
140 | lock->fl.fl_type = fl->fl_type; | |
1da177e4 LT |
141 | } |
142 | ||
143 | static void nlmclnt_release_lockargs(struct nlm_rqst *req) | |
144 | { | |
3a649b88 | 145 | BUG_ON(req->a_args.lock.fl.fl_ops != NULL); |
1da177e4 LT |
146 | } |
147 | ||
1093a60e CL |
148 | /** |
149 | * nlmclnt_proc - Perform a single client-side lock request | |
150 | * @host: address of a valid nlm_host context representing the NLM server | |
151 | * @cmd: fcntl-style file lock operation to perform | |
152 | * @fl: address of arguments for the lock operation | |
153 | * | |
1da177e4 | 154 | */ |
1093a60e | 155 | int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl) |
1da177e4 | 156 | { |
92737230 | 157 | struct nlm_rqst *call; |
1da177e4 LT |
158 | sigset_t oldset; |
159 | unsigned long flags; | |
1093a60e | 160 | int status; |
1da177e4 | 161 | |
1093a60e | 162 | nlm_get_host(host); |
92737230 TM |
163 | call = nlm_alloc_call(host); |
164 | if (call == NULL) | |
165 | return -ENOMEM; | |
1da177e4 | 166 | |
92737230 TM |
167 | nlmclnt_locks_init_private(fl, host); |
168 | /* Set up the argument struct */ | |
169 | nlmclnt_setlockargs(call, fl); | |
1da177e4 LT |
170 | |
171 | /* Keep the old signal mask */ | |
172 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
173 | oldset = current->blocked; | |
174 | ||
175 | /* If we're cleaning up locks because the process is exiting, | |
176 | * perform the RPC call asynchronously. */ | |
177 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) | |
178 | && fl->fl_type == F_UNLCK | |
179 | && (current->flags & PF_EXITING)) { | |
180 | sigfillset(¤t->blocked); /* Mask all signals */ | |
181 | recalc_sigpending(); | |
1da177e4 | 182 | |
1da177e4 | 183 | call->a_flags = RPC_TASK_ASYNC; |
1da177e4 | 184 | } |
92737230 | 185 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
1da177e4 LT |
186 | |
187 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { | |
188 | if (fl->fl_type != F_UNLCK) { | |
189 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
190 | status = nlmclnt_lock(call, fl); | |
191 | } else | |
192 | status = nlmclnt_unlock(call, fl); | |
193 | } else if (IS_GETLK(cmd)) | |
194 | status = nlmclnt_test(call, fl); | |
195 | else | |
196 | status = -EINVAL; | |
197 | ||
92737230 TM |
198 | fl->fl_ops->fl_release_private(fl); |
199 | fl->fl_ops = NULL; | |
200 | ||
1da177e4 LT |
201 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
202 | current->blocked = oldset; | |
203 | recalc_sigpending(); | |
204 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
205 | ||
1da177e4 | 206 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
207 | return status; |
208 | } | |
1093a60e | 209 | EXPORT_SYMBOL_GPL(nlmclnt_proc); |
1da177e4 LT |
210 | |
211 | /* | |
212 | * Allocate an NLM RPC call struct | |
92737230 TM |
213 | * |
214 | * Note: the caller must hold a reference to host. In case of failure, | |
215 | * this reference will be released. | |
1da177e4 | 216 | */ |
92737230 | 217 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
218 | { |
219 | struct nlm_rqst *call; | |
220 | ||
36943fa4 TM |
221 | for(;;) { |
222 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
223 | if (call != NULL) { | |
5e7f37a7 | 224 | atomic_set(&call->a_count, 1); |
1da177e4 LT |
225 | locks_init_lock(&call->a_args.lock.fl); |
226 | locks_init_lock(&call->a_res.lock.fl); | |
92737230 | 227 | call->a_host = host; |
1da177e4 LT |
228 | return call; |
229 | } | |
36943fa4 TM |
230 | if (signalled()) |
231 | break; | |
92737230 | 232 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 233 | schedule_timeout_interruptible(5*HZ); |
1da177e4 | 234 | } |
92737230 | 235 | nlm_release_host(host); |
1da177e4 LT |
236 | return NULL; |
237 | } | |
238 | ||
92737230 TM |
239 | void nlm_release_call(struct nlm_rqst *call) |
240 | { | |
5e7f37a7 TM |
241 | if (!atomic_dec_and_test(&call->a_count)) |
242 | return; | |
92737230 TM |
243 | nlm_release_host(call->a_host); |
244 | nlmclnt_release_lockargs(call); | |
245 | kfree(call); | |
246 | } | |
247 | ||
248 | static void nlmclnt_rpc_release(void *data) | |
249 | { | |
65fdf7d2 | 250 | nlm_release_call(data); |
92737230 TM |
251 | } |
252 | ||
1da177e4 LT |
253 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
254 | { | |
255 | DEFINE_WAIT(wait); | |
256 | int status = -EINTR; | |
257 | ||
258 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
259 | if (!signalled ()) { | |
260 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 261 | try_to_freeze(); |
1da177e4 LT |
262 | if (!signalled ()) |
263 | status = 0; | |
264 | } | |
265 | finish_wait(queue, &wait); | |
266 | return status; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Generic NLM call | |
271 | */ | |
272 | static int | |
273 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
274 | { | |
275 | struct nlm_host *host = req->a_host; | |
276 | struct rpc_clnt *clnt; | |
277 | struct nlm_args *argp = &req->a_args; | |
278 | struct nlm_res *resp = &req->a_res; | |
279 | struct rpc_message msg = { | |
280 | .rpc_argp = argp, | |
281 | .rpc_resp = resp, | |
282 | }; | |
283 | int status; | |
284 | ||
285 | dprintk("lockd: call procedure %d on %s\n", | |
286 | (int)proc, host->h_name); | |
287 | ||
288 | do { | |
289 | if (host->h_reclaiming && !argp->reclaim) | |
290 | goto in_grace_period; | |
291 | ||
292 | /* If we have no RPC client yet, create one. */ | |
293 | if ((clnt = nlm_bind_host(host)) == NULL) | |
294 | return -ENOLCK; | |
295 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
296 | ||
297 | /* Perform the RPC call. If an error occurs, try again */ | |
298 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
299 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
300 | switch (status) { | |
301 | case -EPROTONOSUPPORT: | |
302 | status = -EINVAL; | |
303 | break; | |
304 | case -ECONNREFUSED: | |
305 | case -ETIMEDOUT: | |
306 | case -ENOTCONN: | |
307 | nlm_rebind_host(host); | |
308 | status = -EAGAIN; | |
309 | break; | |
310 | case -ERESTARTSYS: | |
311 | return signalled () ? -EINTR : status; | |
312 | default: | |
313 | break; | |
314 | } | |
315 | break; | |
316 | } else | |
e8c5c045 | 317 | if (resp->status == nlm_lck_denied_grace_period) { |
1da177e4 LT |
318 | dprintk("lockd: server in grace period\n"); |
319 | if (argp->reclaim) { | |
320 | printk(KERN_WARNING | |
321 | "lockd: spurious grace period reject?!\n"); | |
322 | return -ENOLCK; | |
323 | } | |
324 | } else { | |
325 | if (!argp->reclaim) { | |
326 | /* We appear to be out of the grace period */ | |
327 | wake_up_all(&host->h_gracewait); | |
328 | } | |
329 | dprintk("lockd: server returns status %d\n", resp->status); | |
330 | return 0; /* Okay, call complete */ | |
331 | } | |
332 | ||
333 | in_grace_period: | |
334 | /* | |
335 | * The server has rebooted and appears to be in the grace | |
336 | * period during which locks are only allowed to be | |
337 | * reclaimed. | |
338 | * We can only back off and try again later. | |
339 | */ | |
340 | status = nlm_wait_on_grace(&host->h_gracewait); | |
341 | } while (status == 0); | |
342 | ||
343 | return status; | |
344 | } | |
345 | ||
346 | /* | |
347 | * Generic NLM call, async version. | |
348 | */ | |
d4716624 | 349 | static int __nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
350 | { |
351 | struct nlm_host *host = req->a_host; | |
352 | struct rpc_clnt *clnt; | |
1da177e4 LT |
353 | |
354 | dprintk("lockd: call procedure %d on %s (async)\n", | |
355 | (int)proc, host->h_name); | |
356 | ||
357 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
358 | clnt = nlm_bind_host(host); |
359 | if (clnt == NULL) | |
360 | goto out_err; | |
d4716624 | 361 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
1da177e4 | 362 | |
1da177e4 | 363 | /* bootstrap and kick off the async RPC call */ |
a995e9eb | 364 | return rpc_call_async(clnt, msg, RPC_TASK_ASYNC, tk_ops, req); |
92737230 | 365 | out_err: |
a995e9eb TM |
366 | tk_ops->rpc_release(req); |
367 | return -ENOLCK; | |
1da177e4 LT |
368 | } |
369 | ||
d4716624 TM |
370 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
371 | { | |
372 | struct rpc_message msg = { | |
373 | .rpc_argp = &req->a_args, | |
374 | .rpc_resp = &req->a_res, | |
375 | }; | |
376 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
377 | } | |
378 | ||
379 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
380 | { | |
381 | struct rpc_message msg = { | |
382 | .rpc_argp = &req->a_res, | |
383 | }; | |
384 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
385 | } | |
386 | ||
1da177e4 LT |
387 | /* |
388 | * TEST for the presence of a conflicting lock | |
389 | */ | |
390 | static int | |
391 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
392 | { | |
393 | int status; | |
394 | ||
395 | status = nlmclnt_call(req, NLMPROC_TEST); | |
1da177e4 | 396 | if (status < 0) |
92737230 | 397 | goto out; |
1da177e4 | 398 | |
92737230 | 399 | switch (req->a_res.status) { |
e8c5c045 | 400 | case nlm_granted: |
92737230 TM |
401 | fl->fl_type = F_UNLCK; |
402 | break; | |
e8c5c045 | 403 | case nlm_lck_denied: |
92737230 TM |
404 | /* |
405 | * Report the conflicting lock back to the application. | |
406 | */ | |
407 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
408 | fl->fl_end = req->a_res.lock.fl.fl_start; | |
409 | fl->fl_type = req->a_res.lock.fl.fl_type; | |
410 | fl->fl_pid = 0; | |
411 | break; | |
412 | default: | |
413 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 414 | } |
92737230 TM |
415 | out: |
416 | nlm_release_call(req); | |
417 | return status; | |
1da177e4 LT |
418 | } |
419 | ||
420 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
421 | { | |
4c060b53 TM |
422 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
423 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
424 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
425 | } |
426 | ||
427 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
428 | { | |
4c060b53 | 429 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 430 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
431 | } |
432 | ||
433 | static struct file_lock_operations nlmclnt_lock_ops = { | |
434 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
435 | .fl_release_private = nlmclnt_locks_release_private, | |
436 | }; | |
437 | ||
438 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
439 | { | |
440 | BUG_ON(fl->fl_ops != NULL); | |
441 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 442 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 443 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
444 | fl->fl_ops = &nlmclnt_lock_ops; |
445 | } | |
446 | ||
9b073574 | 447 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
448 | { |
449 | int res = 0; | |
450 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
451 | case FL_POSIX: | |
452 | res = posix_lock_file_wait(fl->fl_file, fl); | |
453 | break; | |
454 | case FL_FLOCK: | |
455 | res = flock_lock_file_wait(fl->fl_file, fl); | |
456 | break; | |
457 | default: | |
458 | BUG(); | |
459 | } | |
9b073574 | 460 | return res; |
1da177e4 LT |
461 | } |
462 | ||
463 | /* | |
464 | * LOCK: Try to create a lock | |
465 | * | |
466 | * Programmer Harassment Alert | |
467 | * | |
468 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
469 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
470 | * the lock could be granted. This way, our local process could hang | |
471 | * around forever waiting for the callback. | |
472 | * | |
473 | * Solution A: Implement busy-waiting | |
474 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
475 | * | |
476 | * For now I am implementing solution A, because I hate the idea of | |
477 | * re-implementing lockd for a third time in two months. The async | |
478 | * calls shouldn't be too hard to do, however. | |
479 | * | |
480 | * This is one of the lovely things about standards in the NFS area: | |
481 | * they're so soft and squishy you can't really blame HP for doing this. | |
482 | */ | |
483 | static int | |
484 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
485 | { | |
486 | struct nlm_host *host = req->a_host; | |
487 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 488 | struct nlm_wait *block = NULL; |
01c3b861 | 489 | unsigned char fl_flags = fl->fl_flags; |
3a649b88 | 490 | int status = -ENOLCK; |
1da177e4 | 491 | |
977faf39 | 492 | if (nsm_monitor(host) < 0) { |
1da177e4 LT |
493 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", |
494 | host->h_name); | |
1da177e4 LT |
495 | goto out; |
496 | } | |
01c3b861 TM |
497 | fl->fl_flags |= FL_ACCESS; |
498 | status = do_vfs_lock(fl); | |
4a9af59f | 499 | fl->fl_flags = fl_flags; |
01c3b861 TM |
500 | if (status < 0) |
501 | goto out; | |
1da177e4 | 502 | |
3a649b88 | 503 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 504 | again: |
ecdbf769 | 505 | for(;;) { |
28df955a TM |
506 | /* Reboot protection */ |
507 | fl->fl_u.nfs_fl.state = host->h_state; | |
ecdbf769 TM |
508 | status = nlmclnt_call(req, NLMPROC_LOCK); |
509 | if (status < 0) | |
510 | goto out_unblock; | |
3a649b88 | 511 | if (!req->a_args.block) |
ecdbf769 | 512 | break; |
ecdbf769 | 513 | /* Did a reclaimer thread notify us of a server reboot? */ |
e8c5c045 | 514 | if (resp->status == nlm_lck_denied_grace_period) |
ecdbf769 | 515 | continue; |
e8c5c045 | 516 | if (resp->status != nlm_lck_blocked) |
ecdbf769 | 517 | break; |
3a649b88 TM |
518 | /* Wait on an NLM blocking lock */ |
519 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
520 | /* if we were interrupted. Send a CANCEL request to the server | |
ecdbf769 TM |
521 | * and exit |
522 | */ | |
3a649b88 TM |
523 | if (status < 0) |
524 | goto out_unblock; | |
e8c5c045 | 525 | if (resp->status != nlm_lck_blocked) |
3a649b88 | 526 | break; |
ecdbf769 | 527 | } |
1da177e4 | 528 | |
e8c5c045 | 529 | if (resp->status == nlm_granted) { |
28df955a TM |
530 | down_read(&host->h_rwsem); |
531 | /* Check whether or not the server has rebooted */ | |
532 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
533 | up_read(&host->h_rwsem); | |
534 | goto again; | |
535 | } | |
4c060b53 | 536 | /* Ensure the resulting lock will get added to granted list */ |
4a9af59f | 537 | fl->fl_flags |= FL_SLEEP; |
9b073574 TM |
538 | if (do_vfs_lock(fl) < 0) |
539 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); | |
28df955a | 540 | up_read(&host->h_rwsem); |
4a9af59f | 541 | fl->fl_flags = fl_flags; |
1da177e4 LT |
542 | } |
543 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 544 | out_unblock: |
3a649b88 | 545 | nlmclnt_finish_block(block); |
ecdbf769 | 546 | /* Cancel the blocked request if it is still pending */ |
e8c5c045 | 547 | if (resp->status == nlm_lck_blocked) |
16fb2425 | 548 | nlmclnt_cancel(host, req->a_args.block, fl); |
1da177e4 | 549 | out: |
92737230 | 550 | nlm_release_call(req); |
1da177e4 LT |
551 | return status; |
552 | } | |
553 | ||
554 | /* | |
555 | * RECLAIM: Try to reclaim a lock | |
556 | */ | |
557 | int | |
558 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
559 | { | |
560 | struct nlm_rqst reqst, *req; | |
561 | int status; | |
562 | ||
563 | req = &reqst; | |
564 | memset(req, 0, sizeof(*req)); | |
565 | locks_init_lock(&req->a_args.lock.fl); | |
566 | locks_init_lock(&req->a_res.lock.fl); | |
567 | req->a_host = host; | |
568 | req->a_flags = 0; | |
569 | ||
570 | /* Set up the argument struct */ | |
571 | nlmclnt_setlockargs(req, fl); | |
572 | req->a_args.reclaim = 1; | |
573 | ||
574 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
e8c5c045 | 575 | && req->a_res.status == nlm_granted) |
1da177e4 LT |
576 | return 0; |
577 | ||
578 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
579 | "(errno %d, status %d)\n", fl->fl_pid, | |
e8c5c045 | 580 | status, ntohl(req->a_res.status)); |
1da177e4 LT |
581 | |
582 | /* | |
583 | * FIXME: This is a serious failure. We can | |
584 | * | |
585 | * a. Ignore the problem | |
586 | * b. Send the owning process some signal (Linux doesn't have | |
587 | * SIGLOST, though...) | |
588 | * c. Retry the operation | |
589 | * | |
590 | * Until someone comes up with a simple implementation | |
591 | * for b or c, I'll choose option a. | |
592 | */ | |
593 | ||
594 | return -ENOLCK; | |
595 | } | |
596 | ||
597 | /* | |
598 | * UNLOCK: remove an existing lock | |
599 | */ | |
600 | static int | |
601 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
602 | { | |
28df955a | 603 | struct nlm_host *host = req->a_host; |
1da177e4 | 604 | struct nlm_res *resp = &req->a_res; |
4a9af59f TM |
605 | int status; |
606 | unsigned char fl_flags = fl->fl_flags; | |
1da177e4 | 607 | |
30f4e20a TM |
608 | /* |
609 | * Note: the server is supposed to either grant us the unlock | |
610 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
611 | * case, we want to unlock. | |
612 | */ | |
9b073574 | 613 | fl->fl_flags |= FL_EXISTS; |
28df955a | 614 | down_read(&host->h_rwsem); |
4a9af59f TM |
615 | status = do_vfs_lock(fl); |
616 | up_read(&host->h_rwsem); | |
617 | fl->fl_flags = fl_flags; | |
618 | if (status == -ENOENT) { | |
619 | status = 0; | |
9b073574 TM |
620 | goto out; |
621 | } | |
30f4e20a | 622 | |
92737230 TM |
623 | if (req->a_flags & RPC_TASK_ASYNC) |
624 | return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 LT |
625 | |
626 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
1da177e4 | 627 | if (status < 0) |
92737230 | 628 | goto out; |
1da177e4 | 629 | |
e8c5c045 | 630 | if (resp->status == nlm_granted) |
92737230 | 631 | goto out; |
1da177e4 | 632 | |
e8c5c045 | 633 | if (resp->status != nlm_lck_denied_nolocks) |
1da177e4 | 634 | printk("lockd: unexpected unlock status: %d\n", resp->status); |
1da177e4 | 635 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
636 | status = -ENOLCK; |
637 | out: | |
638 | nlm_release_call(req); | |
639 | return status; | |
1da177e4 LT |
640 | } |
641 | ||
963d8fe5 | 642 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 643 | { |
963d8fe5 | 644 | struct nlm_rqst *req = data; |
e8c5c045 | 645 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
646 | |
647 | if (RPC_ASSASSINATED(task)) | |
648 | goto die; | |
649 | ||
650 | if (task->tk_status < 0) { | |
651 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
652 | goto retry_rebind; | |
653 | } | |
654 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
655 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
656 | goto retry_unlock; | |
657 | } | |
658 | if (status != NLM_LCK_GRANTED) | |
659 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
660 | die: | |
1da177e4 LT |
661 | return; |
662 | retry_rebind: | |
663 | nlm_rebind_host(req->a_host); | |
664 | retry_unlock: | |
665 | rpc_restart_call(task); | |
666 | } | |
667 | ||
963d8fe5 TM |
668 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
669 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 670 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
671 | }; |
672 | ||
1da177e4 LT |
673 | /* |
674 | * Cancel a blocked lock request. | |
675 | * We always use an async RPC call for this in order not to hang a | |
676 | * process that has been Ctrl-C'ed. | |
677 | */ | |
16fb2425 | 678 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
679 | { |
680 | struct nlm_rqst *req; | |
681 | unsigned long flags; | |
682 | sigset_t oldset; | |
683 | int status; | |
684 | ||
685 | /* Block all signals while setting up call */ | |
686 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
687 | oldset = current->blocked; | |
688 | sigfillset(¤t->blocked); | |
689 | recalc_sigpending(); | |
690 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
691 | ||
92737230 | 692 | req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4 LT |
693 | if (!req) |
694 | return -ENOMEM; | |
1da177e4 LT |
695 | req->a_flags = RPC_TASK_ASYNC; |
696 | ||
697 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 698 | req->a_args.block = block; |
1da177e4 | 699 | |
92737230 | 700 | status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
1da177e4 LT |
701 | |
702 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
703 | current->blocked = oldset; | |
704 | recalc_sigpending(); | |
705 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
706 | ||
707 | return status; | |
708 | } | |
709 | ||
963d8fe5 | 710 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 711 | { |
963d8fe5 | 712 | struct nlm_rqst *req = data; |
e8c5c045 | 713 | u32 status = ntohl(req->a_res.status); |
1da177e4 LT |
714 | |
715 | if (RPC_ASSASSINATED(task)) | |
716 | goto die; | |
717 | ||
718 | if (task->tk_status < 0) { | |
719 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
720 | task->tk_status); | |
721 | goto retry_cancel; | |
722 | } | |
723 | ||
c041b5ff | 724 | dprintk("lockd: cancel status %u (task %u)\n", |
e8c5c045 | 725 | status, task->tk_pid); |
1da177e4 | 726 | |
e8c5c045 | 727 | switch (status) { |
1da177e4 LT |
728 | case NLM_LCK_GRANTED: |
729 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 730 | case NLM_LCK_DENIED: |
1da177e4 LT |
731 | /* Everything's good */ |
732 | break; | |
733 | case NLM_LCK_DENIED_NOLOCKS: | |
734 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
735 | goto retry_cancel; | |
736 | default: | |
737 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
e8c5c045 | 738 | status); |
1da177e4 LT |
739 | } |
740 | ||
741 | die: | |
1da177e4 LT |
742 | return; |
743 | ||
744 | retry_cancel: | |
aaaa9942 TM |
745 | /* Don't ever retry more than 3 times */ |
746 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
747 | goto die; | |
1da177e4 LT |
748 | nlm_rebind_host(req->a_host); |
749 | rpc_restart_call(task); | |
750 | rpc_delay(task, 30 * HZ); | |
751 | } | |
752 | ||
963d8fe5 TM |
753 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
754 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 755 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
756 | }; |
757 | ||
1da177e4 LT |
758 | /* |
759 | * Convert an NLM status code to a generic kernel errno | |
760 | */ | |
761 | static int | |
e8c5c045 | 762 | nlm_stat_to_errno(__be32 status) |
1da177e4 | 763 | { |
e8c5c045 | 764 | switch(ntohl(status)) { |
1da177e4 LT |
765 | case NLM_LCK_GRANTED: |
766 | return 0; | |
767 | case NLM_LCK_DENIED: | |
768 | return -EAGAIN; | |
769 | case NLM_LCK_DENIED_NOLOCKS: | |
770 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
771 | return -ENOLCK; | |
772 | case NLM_LCK_BLOCKED: | |
773 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
774 | return -ENOLCK; | |
775 | #ifdef CONFIG_LOCKD_V4 | |
776 | case NLM_DEADLCK: | |
777 | return -EDEADLK; | |
778 | case NLM_ROFS: | |
779 | return -EROFS; | |
780 | case NLM_STALE_FH: | |
781 | return -ESTALE; | |
782 | case NLM_FBIG: | |
783 | return -EOVERFLOW; | |
784 | case NLM_FAILED: | |
785 | return -ENOLCK; | |
786 | #endif | |
787 | } | |
788 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
789 | return -ENOLCK; | |
790 | } |