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> | |
15 | #include <linux/smp_lock.h> | |
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 *); | |
1da177e4 LT |
29 | static int nlm_stat_to_errno(u32 stat); |
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; | |
131 | memcpy(&lock->fh, NFS_FH(fl->fl_file->f_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 | ||
1da177e4 LT |
148 | /* |
149 | * This is the main entry point for the NLM client. | |
150 | */ | |
151 | int | |
152 | nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl) | |
153 | { | |
44c31be2 CL |
154 | struct rpc_clnt *client = NFS_CLIENT(inode); |
155 | struct sockaddr_in addr; | |
db4e4c9a | 156 | struct nfs_server *nfssrv = NFS_SERVER(inode); |
1da177e4 | 157 | struct nlm_host *host; |
92737230 | 158 | struct nlm_rqst *call; |
1da177e4 LT |
159 | sigset_t oldset; |
160 | unsigned long flags; | |
44c31be2 | 161 | int status, vers; |
1da177e4 LT |
162 | |
163 | vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1; | |
164 | if (NFS_PROTO(inode)->version > 3) { | |
165 | printk(KERN_NOTICE "NFSv4 file locking not implemented!\n"); | |
166 | return -ENOLCK; | |
167 | } | |
168 | ||
44c31be2 | 169 | rpc_peeraddr(client, (struct sockaddr *) &addr, sizeof(addr)); |
db4e4c9a OK |
170 | host = nlmclnt_lookup_host(&addr, client->cl_xprt->prot, vers, |
171 | nfssrv->nfs_client->cl_hostname, | |
172 | strlen(nfssrv->nfs_client->cl_hostname)); | |
92737230 | 173 | if (host == NULL) |
1da177e4 LT |
174 | return -ENOLCK; |
175 | ||
92737230 TM |
176 | call = nlm_alloc_call(host); |
177 | if (call == NULL) | |
178 | return -ENOMEM; | |
1da177e4 | 179 | |
92737230 TM |
180 | nlmclnt_locks_init_private(fl, host); |
181 | /* Set up the argument struct */ | |
182 | nlmclnt_setlockargs(call, fl); | |
1da177e4 LT |
183 | |
184 | /* Keep the old signal mask */ | |
185 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
186 | oldset = current->blocked; | |
187 | ||
188 | /* If we're cleaning up locks because the process is exiting, | |
189 | * perform the RPC call asynchronously. */ | |
190 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) | |
191 | && fl->fl_type == F_UNLCK | |
192 | && (current->flags & PF_EXITING)) { | |
193 | sigfillset(¤t->blocked); /* Mask all signals */ | |
194 | recalc_sigpending(); | |
1da177e4 | 195 | |
1da177e4 | 196 | call->a_flags = RPC_TASK_ASYNC; |
1da177e4 | 197 | } |
92737230 | 198 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
1da177e4 LT |
199 | |
200 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { | |
201 | if (fl->fl_type != F_UNLCK) { | |
202 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
203 | status = nlmclnt_lock(call, fl); | |
204 | } else | |
205 | status = nlmclnt_unlock(call, fl); | |
206 | } else if (IS_GETLK(cmd)) | |
207 | status = nlmclnt_test(call, fl); | |
208 | else | |
209 | status = -EINVAL; | |
210 | ||
92737230 TM |
211 | fl->fl_ops->fl_release_private(fl); |
212 | fl->fl_ops = NULL; | |
213 | ||
1da177e4 LT |
214 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
215 | current->blocked = oldset; | |
216 | recalc_sigpending(); | |
217 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
218 | ||
1da177e4 | 219 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
220 | return status; |
221 | } | |
222 | EXPORT_SYMBOL(nlmclnt_proc); | |
223 | ||
224 | /* | |
225 | * Allocate an NLM RPC call struct | |
92737230 TM |
226 | * |
227 | * Note: the caller must hold a reference to host. In case of failure, | |
228 | * this reference will be released. | |
1da177e4 | 229 | */ |
92737230 | 230 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
231 | { |
232 | struct nlm_rqst *call; | |
233 | ||
36943fa4 TM |
234 | for(;;) { |
235 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
236 | if (call != NULL) { | |
1da177e4 LT |
237 | locks_init_lock(&call->a_args.lock.fl); |
238 | locks_init_lock(&call->a_res.lock.fl); | |
92737230 | 239 | call->a_host = host; |
1da177e4 LT |
240 | return call; |
241 | } | |
36943fa4 TM |
242 | if (signalled()) |
243 | break; | |
92737230 | 244 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 245 | schedule_timeout_interruptible(5*HZ); |
1da177e4 | 246 | } |
92737230 | 247 | nlm_release_host(host); |
1da177e4 LT |
248 | return NULL; |
249 | } | |
250 | ||
92737230 TM |
251 | void nlm_release_call(struct nlm_rqst *call) |
252 | { | |
253 | nlm_release_host(call->a_host); | |
254 | nlmclnt_release_lockargs(call); | |
255 | kfree(call); | |
256 | } | |
257 | ||
258 | static void nlmclnt_rpc_release(void *data) | |
259 | { | |
260 | return nlm_release_call(data); | |
261 | } | |
262 | ||
1da177e4 LT |
263 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
264 | { | |
265 | DEFINE_WAIT(wait); | |
266 | int status = -EINTR; | |
267 | ||
268 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
269 | if (!signalled ()) { | |
270 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 271 | try_to_freeze(); |
1da177e4 LT |
272 | if (!signalled ()) |
273 | status = 0; | |
274 | } | |
275 | finish_wait(queue, &wait); | |
276 | return status; | |
277 | } | |
278 | ||
279 | /* | |
280 | * Generic NLM call | |
281 | */ | |
282 | static int | |
283 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
284 | { | |
285 | struct nlm_host *host = req->a_host; | |
286 | struct rpc_clnt *clnt; | |
287 | struct nlm_args *argp = &req->a_args; | |
288 | struct nlm_res *resp = &req->a_res; | |
289 | struct rpc_message msg = { | |
290 | .rpc_argp = argp, | |
291 | .rpc_resp = resp, | |
292 | }; | |
293 | int status; | |
294 | ||
295 | dprintk("lockd: call procedure %d on %s\n", | |
296 | (int)proc, host->h_name); | |
297 | ||
298 | do { | |
299 | if (host->h_reclaiming && !argp->reclaim) | |
300 | goto in_grace_period; | |
301 | ||
302 | /* If we have no RPC client yet, create one. */ | |
303 | if ((clnt = nlm_bind_host(host)) == NULL) | |
304 | return -ENOLCK; | |
305 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
306 | ||
307 | /* Perform the RPC call. If an error occurs, try again */ | |
308 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
309 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
310 | switch (status) { | |
311 | case -EPROTONOSUPPORT: | |
312 | status = -EINVAL; | |
313 | break; | |
314 | case -ECONNREFUSED: | |
315 | case -ETIMEDOUT: | |
316 | case -ENOTCONN: | |
317 | nlm_rebind_host(host); | |
318 | status = -EAGAIN; | |
319 | break; | |
320 | case -ERESTARTSYS: | |
321 | return signalled () ? -EINTR : status; | |
322 | default: | |
323 | break; | |
324 | } | |
325 | break; | |
326 | } else | |
327 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
328 | dprintk("lockd: server in grace period\n"); | |
329 | if (argp->reclaim) { | |
330 | printk(KERN_WARNING | |
331 | "lockd: spurious grace period reject?!\n"); | |
332 | return -ENOLCK; | |
333 | } | |
334 | } else { | |
335 | if (!argp->reclaim) { | |
336 | /* We appear to be out of the grace period */ | |
337 | wake_up_all(&host->h_gracewait); | |
338 | } | |
339 | dprintk("lockd: server returns status %d\n", resp->status); | |
340 | return 0; /* Okay, call complete */ | |
341 | } | |
342 | ||
343 | in_grace_period: | |
344 | /* | |
345 | * The server has rebooted and appears to be in the grace | |
346 | * period during which locks are only allowed to be | |
347 | * reclaimed. | |
348 | * We can only back off and try again later. | |
349 | */ | |
350 | status = nlm_wait_on_grace(&host->h_gracewait); | |
351 | } while (status == 0); | |
352 | ||
353 | return status; | |
354 | } | |
355 | ||
356 | /* | |
357 | * Generic NLM call, async version. | |
358 | */ | |
d4716624 | 359 | static int __nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
360 | { |
361 | struct nlm_host *host = req->a_host; | |
362 | struct rpc_clnt *clnt; | |
92737230 | 363 | int status = -ENOLCK; |
1da177e4 LT |
364 | |
365 | dprintk("lockd: call procedure %d on %s (async)\n", | |
366 | (int)proc, host->h_name); | |
367 | ||
368 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
369 | clnt = nlm_bind_host(host); |
370 | if (clnt == NULL) | |
371 | goto out_err; | |
d4716624 | 372 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
1da177e4 | 373 | |
1da177e4 | 374 | /* bootstrap and kick off the async RPC call */ |
d4716624 | 375 | status = rpc_call_async(clnt, msg, RPC_TASK_ASYNC, tk_ops, req); |
92737230 TM |
376 | if (status == 0) |
377 | return 0; | |
378 | out_err: | |
379 | nlm_release_call(req); | |
1da177e4 LT |
380 | return status; |
381 | } | |
382 | ||
d4716624 TM |
383 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
384 | { | |
385 | struct rpc_message msg = { | |
386 | .rpc_argp = &req->a_args, | |
387 | .rpc_resp = &req->a_res, | |
388 | }; | |
389 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
390 | } | |
391 | ||
392 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
393 | { | |
394 | struct rpc_message msg = { | |
395 | .rpc_argp = &req->a_res, | |
396 | }; | |
397 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
398 | } | |
399 | ||
1da177e4 LT |
400 | /* |
401 | * TEST for the presence of a conflicting lock | |
402 | */ | |
403 | static int | |
404 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
405 | { | |
406 | int status; | |
407 | ||
408 | status = nlmclnt_call(req, NLMPROC_TEST); | |
1da177e4 | 409 | if (status < 0) |
92737230 | 410 | goto out; |
1da177e4 | 411 | |
92737230 TM |
412 | switch (req->a_res.status) { |
413 | case NLM_LCK_GRANTED: | |
414 | fl->fl_type = F_UNLCK; | |
415 | break; | |
416 | case NLM_LCK_DENIED: | |
417 | /* | |
418 | * Report the conflicting lock back to the application. | |
419 | */ | |
420 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
421 | fl->fl_end = req->a_res.lock.fl.fl_start; | |
422 | fl->fl_type = req->a_res.lock.fl.fl_type; | |
423 | fl->fl_pid = 0; | |
424 | break; | |
425 | default: | |
426 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 427 | } |
92737230 TM |
428 | out: |
429 | nlm_release_call(req); | |
430 | return status; | |
1da177e4 LT |
431 | } |
432 | ||
433 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
434 | { | |
4c060b53 TM |
435 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
436 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
437 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
438 | } |
439 | ||
440 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
441 | { | |
4c060b53 | 442 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 443 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
444 | } |
445 | ||
446 | static struct file_lock_operations nlmclnt_lock_ops = { | |
447 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
448 | .fl_release_private = nlmclnt_locks_release_private, | |
449 | }; | |
450 | ||
451 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
452 | { | |
453 | BUG_ON(fl->fl_ops != NULL); | |
454 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 455 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 456 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
457 | fl->fl_ops = &nlmclnt_lock_ops; |
458 | } | |
459 | ||
9b073574 | 460 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
461 | { |
462 | int res = 0; | |
463 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
464 | case FL_POSIX: | |
465 | res = posix_lock_file_wait(fl->fl_file, fl); | |
466 | break; | |
467 | case FL_FLOCK: | |
468 | res = flock_lock_file_wait(fl->fl_file, fl); | |
469 | break; | |
470 | default: | |
471 | BUG(); | |
472 | } | |
9b073574 | 473 | return res; |
1da177e4 LT |
474 | } |
475 | ||
476 | /* | |
477 | * LOCK: Try to create a lock | |
478 | * | |
479 | * Programmer Harassment Alert | |
480 | * | |
481 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
482 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
483 | * the lock could be granted. This way, our local process could hang | |
484 | * around forever waiting for the callback. | |
485 | * | |
486 | * Solution A: Implement busy-waiting | |
487 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
488 | * | |
489 | * For now I am implementing solution A, because I hate the idea of | |
490 | * re-implementing lockd for a third time in two months. The async | |
491 | * calls shouldn't be too hard to do, however. | |
492 | * | |
493 | * This is one of the lovely things about standards in the NFS area: | |
494 | * they're so soft and squishy you can't really blame HP for doing this. | |
495 | */ | |
496 | static int | |
497 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
498 | { | |
499 | struct nlm_host *host = req->a_host; | |
500 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 501 | struct nlm_wait *block = NULL; |
01c3b861 | 502 | unsigned char fl_flags = fl->fl_flags; |
3a649b88 | 503 | int status = -ENOLCK; |
1da177e4 | 504 | |
977faf39 | 505 | if (nsm_monitor(host) < 0) { |
1da177e4 LT |
506 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", |
507 | host->h_name); | |
1da177e4 LT |
508 | goto out; |
509 | } | |
01c3b861 TM |
510 | fl->fl_flags |= FL_ACCESS; |
511 | status = do_vfs_lock(fl); | |
512 | if (status < 0) | |
513 | goto out; | |
1da177e4 | 514 | |
3a649b88 | 515 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 516 | again: |
ecdbf769 | 517 | for(;;) { |
28df955a TM |
518 | /* Reboot protection */ |
519 | fl->fl_u.nfs_fl.state = host->h_state; | |
ecdbf769 TM |
520 | status = nlmclnt_call(req, NLMPROC_LOCK); |
521 | if (status < 0) | |
522 | goto out_unblock; | |
3a649b88 | 523 | if (!req->a_args.block) |
ecdbf769 | 524 | break; |
ecdbf769 TM |
525 | /* Did a reclaimer thread notify us of a server reboot? */ |
526 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) | |
527 | continue; | |
528 | if (resp->status != NLM_LCK_BLOCKED) | |
529 | break; | |
3a649b88 TM |
530 | /* Wait on an NLM blocking lock */ |
531 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
532 | /* if we were interrupted. Send a CANCEL request to the server | |
ecdbf769 TM |
533 | * and exit |
534 | */ | |
3a649b88 TM |
535 | if (status < 0) |
536 | goto out_unblock; | |
537 | if (resp->status != NLM_LCK_BLOCKED) | |
538 | break; | |
ecdbf769 | 539 | } |
1da177e4 LT |
540 | |
541 | if (resp->status == NLM_LCK_GRANTED) { | |
28df955a TM |
542 | down_read(&host->h_rwsem); |
543 | /* Check whether or not the server has rebooted */ | |
544 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
545 | up_read(&host->h_rwsem); | |
546 | goto again; | |
547 | } | |
4c060b53 | 548 | /* Ensure the resulting lock will get added to granted list */ |
01c3b861 | 549 | fl->fl_flags = fl_flags | FL_SLEEP; |
9b073574 TM |
550 | if (do_vfs_lock(fl) < 0) |
551 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); | |
28df955a | 552 | up_read(&host->h_rwsem); |
1da177e4 LT |
553 | } |
554 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 555 | out_unblock: |
3a649b88 | 556 | nlmclnt_finish_block(block); |
ecdbf769 TM |
557 | /* Cancel the blocked request if it is still pending */ |
558 | if (resp->status == NLM_LCK_BLOCKED) | |
16fb2425 | 559 | nlmclnt_cancel(host, req->a_args.block, fl); |
1da177e4 | 560 | out: |
92737230 | 561 | nlm_release_call(req); |
01c3b861 | 562 | fl->fl_flags = fl_flags; |
1da177e4 LT |
563 | return status; |
564 | } | |
565 | ||
566 | /* | |
567 | * RECLAIM: Try to reclaim a lock | |
568 | */ | |
569 | int | |
570 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
571 | { | |
572 | struct nlm_rqst reqst, *req; | |
573 | int status; | |
574 | ||
575 | req = &reqst; | |
576 | memset(req, 0, sizeof(*req)); | |
577 | locks_init_lock(&req->a_args.lock.fl); | |
578 | locks_init_lock(&req->a_res.lock.fl); | |
579 | req->a_host = host; | |
580 | req->a_flags = 0; | |
581 | ||
582 | /* Set up the argument struct */ | |
583 | nlmclnt_setlockargs(req, fl); | |
584 | req->a_args.reclaim = 1; | |
585 | ||
586 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
587 | && req->a_res.status == NLM_LCK_GRANTED) | |
588 | return 0; | |
589 | ||
590 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
591 | "(errno %d, status %d)\n", fl->fl_pid, | |
592 | status, req->a_res.status); | |
593 | ||
594 | /* | |
595 | * FIXME: This is a serious failure. We can | |
596 | * | |
597 | * a. Ignore the problem | |
598 | * b. Send the owning process some signal (Linux doesn't have | |
599 | * SIGLOST, though...) | |
600 | * c. Retry the operation | |
601 | * | |
602 | * Until someone comes up with a simple implementation | |
603 | * for b or c, I'll choose option a. | |
604 | */ | |
605 | ||
606 | return -ENOLCK; | |
607 | } | |
608 | ||
609 | /* | |
610 | * UNLOCK: remove an existing lock | |
611 | */ | |
612 | static int | |
613 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
614 | { | |
28df955a | 615 | struct nlm_host *host = req->a_host; |
1da177e4 | 616 | struct nlm_res *resp = &req->a_res; |
9b073574 | 617 | int status = 0; |
1da177e4 | 618 | |
30f4e20a TM |
619 | /* |
620 | * Note: the server is supposed to either grant us the unlock | |
621 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
622 | * case, we want to unlock. | |
623 | */ | |
9b073574 | 624 | fl->fl_flags |= FL_EXISTS; |
28df955a | 625 | down_read(&host->h_rwsem); |
9b073574 TM |
626 | if (do_vfs_lock(fl) == -ENOENT) { |
627 | up_read(&host->h_rwsem); | |
628 | goto out; | |
629 | } | |
28df955a | 630 | up_read(&host->h_rwsem); |
30f4e20a | 631 | |
92737230 TM |
632 | if (req->a_flags & RPC_TASK_ASYNC) |
633 | return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 LT |
634 | |
635 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
1da177e4 | 636 | if (status < 0) |
92737230 | 637 | goto out; |
1da177e4 | 638 | |
1da177e4 | 639 | if (resp->status == NLM_LCK_GRANTED) |
92737230 | 640 | goto out; |
1da177e4 LT |
641 | |
642 | if (resp->status != NLM_LCK_DENIED_NOLOCKS) | |
643 | printk("lockd: unexpected unlock status: %d\n", resp->status); | |
1da177e4 | 644 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
645 | status = -ENOLCK; |
646 | out: | |
647 | nlm_release_call(req); | |
648 | return status; | |
1da177e4 LT |
649 | } |
650 | ||
963d8fe5 | 651 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 652 | { |
963d8fe5 | 653 | struct nlm_rqst *req = data; |
1da177e4 LT |
654 | int status = req->a_res.status; |
655 | ||
656 | if (RPC_ASSASSINATED(task)) | |
657 | goto die; | |
658 | ||
659 | if (task->tk_status < 0) { | |
660 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
661 | goto retry_rebind; | |
662 | } | |
663 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
664 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
665 | goto retry_unlock; | |
666 | } | |
667 | if (status != NLM_LCK_GRANTED) | |
668 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
669 | die: | |
1da177e4 LT |
670 | return; |
671 | retry_rebind: | |
672 | nlm_rebind_host(req->a_host); | |
673 | retry_unlock: | |
674 | rpc_restart_call(task); | |
675 | } | |
676 | ||
963d8fe5 TM |
677 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
678 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 679 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
680 | }; |
681 | ||
1da177e4 LT |
682 | /* |
683 | * Cancel a blocked lock request. | |
684 | * We always use an async RPC call for this in order not to hang a | |
685 | * process that has been Ctrl-C'ed. | |
686 | */ | |
16fb2425 | 687 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
688 | { |
689 | struct nlm_rqst *req; | |
690 | unsigned long flags; | |
691 | sigset_t oldset; | |
692 | int status; | |
693 | ||
694 | /* Block all signals while setting up call */ | |
695 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
696 | oldset = current->blocked; | |
697 | sigfillset(¤t->blocked); | |
698 | recalc_sigpending(); | |
699 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
700 | ||
92737230 | 701 | req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4 LT |
702 | if (!req) |
703 | return -ENOMEM; | |
1da177e4 LT |
704 | req->a_flags = RPC_TASK_ASYNC; |
705 | ||
706 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 707 | req->a_args.block = block; |
1da177e4 | 708 | |
92737230 | 709 | status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
1da177e4 LT |
710 | |
711 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
712 | current->blocked = oldset; | |
713 | recalc_sigpending(); | |
714 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
715 | ||
716 | return status; | |
717 | } | |
718 | ||
963d8fe5 | 719 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 720 | { |
963d8fe5 | 721 | struct nlm_rqst *req = data; |
1da177e4 LT |
722 | |
723 | if (RPC_ASSASSINATED(task)) | |
724 | goto die; | |
725 | ||
726 | if (task->tk_status < 0) { | |
727 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
728 | task->tk_status); | |
729 | goto retry_cancel; | |
730 | } | |
731 | ||
732 | dprintk("lockd: cancel status %d (task %d)\n", | |
733 | req->a_res.status, task->tk_pid); | |
734 | ||
735 | switch (req->a_res.status) { | |
736 | case NLM_LCK_GRANTED: | |
737 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 738 | case NLM_LCK_DENIED: |
1da177e4 LT |
739 | /* Everything's good */ |
740 | break; | |
741 | case NLM_LCK_DENIED_NOLOCKS: | |
742 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
743 | goto retry_cancel; | |
744 | default: | |
745 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
746 | req->a_res.status); | |
747 | } | |
748 | ||
749 | die: | |
1da177e4 LT |
750 | return; |
751 | ||
752 | retry_cancel: | |
aaaa9942 TM |
753 | /* Don't ever retry more than 3 times */ |
754 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
755 | goto die; | |
1da177e4 LT |
756 | nlm_rebind_host(req->a_host); |
757 | rpc_restart_call(task); | |
758 | rpc_delay(task, 30 * HZ); | |
759 | } | |
760 | ||
963d8fe5 TM |
761 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
762 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 763 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
764 | }; |
765 | ||
1da177e4 LT |
766 | /* |
767 | * Convert an NLM status code to a generic kernel errno | |
768 | */ | |
769 | static int | |
770 | nlm_stat_to_errno(u32 status) | |
771 | { | |
772 | switch(status) { | |
773 | case NLM_LCK_GRANTED: | |
774 | return 0; | |
775 | case NLM_LCK_DENIED: | |
776 | return -EAGAIN; | |
777 | case NLM_LCK_DENIED_NOLOCKS: | |
778 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
779 | return -ENOLCK; | |
780 | case NLM_LCK_BLOCKED: | |
781 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
782 | return -ENOLCK; | |
783 | #ifdef CONFIG_LOCKD_V4 | |
784 | case NLM_DEADLCK: | |
785 | return -EDEADLK; | |
786 | case NLM_ROFS: | |
787 | return -EROFS; | |
788 | case NLM_STALE_FH: | |
789 | return -ESTALE; | |
790 | case NLM_FBIG: | |
791 | return -EOVERFLOW; | |
792 | case NLM_FAILED: | |
793 | return -ENOLCK; | |
794 | #endif | |
795 | } | |
796 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
797 | return -ENOLCK; | |
798 | } |