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> | |
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> | |
20 | #include <linux/lockd/sm_inter.h> | |
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 *); | |
1da177e4 LT |
30 | static int nlm_stat_to_errno(u32 stat); |
31 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); | |
16fb2425 | 32 | static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
1da177e4 | 33 | |
963d8fe5 TM |
34 | static const struct rpc_call_ops nlmclnt_unlock_ops; |
35 | static const struct rpc_call_ops nlmclnt_cancel_ops; | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * Cookie counter for NLM requests | |
39 | */ | |
031d869d | 40 | static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
1da177e4 | 41 | |
031d869d | 42 | void nlmclnt_next_cookie(struct nlm_cookie *c) |
1da177e4 | 43 | { |
031d869d OK |
44 | u32 cookie = atomic_inc_return(&nlm_cookie); |
45 | ||
46 | memcpy(c->data, &cookie, 4); | |
1da177e4 | 47 | c->len=4; |
1da177e4 LT |
48 | } |
49 | ||
50 | static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner) | |
51 | { | |
52 | atomic_inc(&lockowner->count); | |
53 | return lockowner; | |
54 | } | |
55 | ||
56 | static void nlm_put_lockowner(struct nlm_lockowner *lockowner) | |
57 | { | |
58 | if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock)) | |
59 | return; | |
60 | list_del(&lockowner->list); | |
61 | spin_unlock(&lockowner->host->h_lock); | |
62 | nlm_release_host(lockowner->host); | |
63 | kfree(lockowner); | |
64 | } | |
65 | ||
66 | static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) | |
67 | { | |
68 | struct nlm_lockowner *lockowner; | |
69 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
70 | if (lockowner->pid == pid) | |
71 | return -EBUSY; | |
72 | } | |
73 | return 0; | |
74 | } | |
75 | ||
76 | static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) | |
77 | { | |
78 | uint32_t res; | |
79 | do { | |
80 | res = host->h_pidcount++; | |
81 | } while (nlm_pidbusy(host, res) < 0); | |
82 | return res; | |
83 | } | |
84 | ||
85 | static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
86 | { | |
87 | struct nlm_lockowner *lockowner; | |
88 | list_for_each_entry(lockowner, &host->h_lockowners, list) { | |
89 | if (lockowner->owner != owner) | |
90 | continue; | |
91 | return nlm_get_lockowner(lockowner); | |
92 | } | |
93 | return NULL; | |
94 | } | |
95 | ||
96 | static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) | |
97 | { | |
98 | struct nlm_lockowner *res, *new = NULL; | |
99 | ||
100 | spin_lock(&host->h_lock); | |
101 | res = __nlm_find_lockowner(host, owner); | |
102 | if (res == NULL) { | |
103 | spin_unlock(&host->h_lock); | |
f52720ca | 104 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
1da177e4 LT |
105 | spin_lock(&host->h_lock); |
106 | res = __nlm_find_lockowner(host, owner); | |
107 | if (res == NULL && new != NULL) { | |
108 | res = new; | |
109 | atomic_set(&new->count, 1); | |
110 | new->owner = owner; | |
111 | new->pid = __nlm_alloc_pid(host); | |
112 | new->host = nlm_get_host(host); | |
113 | list_add(&new->list, &host->h_lockowners); | |
114 | new = NULL; | |
115 | } | |
116 | } | |
117 | spin_unlock(&host->h_lock); | |
f99d49ad | 118 | kfree(new); |
1da177e4 LT |
119 | return res; |
120 | } | |
121 | ||
122 | /* | |
123 | * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls | |
124 | */ | |
125 | static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) | |
126 | { | |
127 | struct nlm_args *argp = &req->a_args; | |
128 | struct nlm_lock *lock = &argp->lock; | |
129 | ||
130 | nlmclnt_next_cookie(&argp->cookie); | |
131 | argp->state = nsm_local_state; | |
225a719f | 132 | memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh)); |
e9ff3990 | 133 | lock->caller = utsname()->nodename; |
1da177e4 | 134 | lock->oh.data = req->a_owner; |
7bab377f TM |
135 | lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
136 | (unsigned int)fl->fl_u.nfs_fl.owner->pid, | |
e9ff3990 | 137 | utsname()->nodename); |
7bab377f | 138 | lock->svid = fl->fl_u.nfs_fl.owner->pid; |
3a649b88 TM |
139 | lock->fl.fl_start = fl->fl_start; |
140 | lock->fl.fl_end = fl->fl_end; | |
141 | lock->fl.fl_type = fl->fl_type; | |
1da177e4 LT |
142 | } |
143 | ||
144 | static void nlmclnt_release_lockargs(struct nlm_rqst *req) | |
145 | { | |
3a649b88 | 146 | BUG_ON(req->a_args.lock.fl.fl_ops != NULL); |
1da177e4 LT |
147 | } |
148 | ||
1da177e4 LT |
149 | /* |
150 | * This is the main entry point for the NLM client. | |
151 | */ | |
152 | int | |
153 | nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl) | |
154 | { | |
44c31be2 CL |
155 | struct rpc_clnt *client = NFS_CLIENT(inode); |
156 | struct sockaddr_in addr; | |
db4e4c9a | 157 | struct nfs_server *nfssrv = NFS_SERVER(inode); |
1da177e4 | 158 | struct nlm_host *host; |
92737230 | 159 | struct nlm_rqst *call; |
1da177e4 LT |
160 | sigset_t oldset; |
161 | unsigned long flags; | |
44c31be2 | 162 | int status, vers; |
1da177e4 LT |
163 | |
164 | vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1; | |
165 | if (NFS_PROTO(inode)->version > 3) { | |
166 | printk(KERN_NOTICE "NFSv4 file locking not implemented!\n"); | |
167 | return -ENOLCK; | |
168 | } | |
169 | ||
44c31be2 | 170 | rpc_peeraddr(client, (struct sockaddr *) &addr, sizeof(addr)); |
db4e4c9a OK |
171 | host = nlmclnt_lookup_host(&addr, client->cl_xprt->prot, vers, |
172 | nfssrv->nfs_client->cl_hostname, | |
173 | strlen(nfssrv->nfs_client->cl_hostname)); | |
92737230 | 174 | if (host == NULL) |
1da177e4 LT |
175 | return -ENOLCK; |
176 | ||
92737230 TM |
177 | call = nlm_alloc_call(host); |
178 | if (call == NULL) | |
179 | return -ENOMEM; | |
1da177e4 | 180 | |
92737230 TM |
181 | nlmclnt_locks_init_private(fl, host); |
182 | /* Set up the argument struct */ | |
183 | nlmclnt_setlockargs(call, fl); | |
1da177e4 LT |
184 | |
185 | /* Keep the old signal mask */ | |
186 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
187 | oldset = current->blocked; | |
188 | ||
189 | /* If we're cleaning up locks because the process is exiting, | |
190 | * perform the RPC call asynchronously. */ | |
191 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) | |
192 | && fl->fl_type == F_UNLCK | |
193 | && (current->flags & PF_EXITING)) { | |
194 | sigfillset(¤t->blocked); /* Mask all signals */ | |
195 | recalc_sigpending(); | |
1da177e4 | 196 | |
1da177e4 | 197 | call->a_flags = RPC_TASK_ASYNC; |
1da177e4 | 198 | } |
92737230 | 199 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
1da177e4 LT |
200 | |
201 | if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { | |
202 | if (fl->fl_type != F_UNLCK) { | |
203 | call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; | |
204 | status = nlmclnt_lock(call, fl); | |
205 | } else | |
206 | status = nlmclnt_unlock(call, fl); | |
207 | } else if (IS_GETLK(cmd)) | |
208 | status = nlmclnt_test(call, fl); | |
209 | else | |
210 | status = -EINVAL; | |
211 | ||
92737230 TM |
212 | fl->fl_ops->fl_release_private(fl); |
213 | fl->fl_ops = NULL; | |
214 | ||
1da177e4 LT |
215 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
216 | current->blocked = oldset; | |
217 | recalc_sigpending(); | |
218 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
219 | ||
1da177e4 | 220 | dprintk("lockd: clnt proc returns %d\n", status); |
1da177e4 LT |
221 | return status; |
222 | } | |
223 | EXPORT_SYMBOL(nlmclnt_proc); | |
224 | ||
225 | /* | |
226 | * Allocate an NLM RPC call struct | |
92737230 TM |
227 | * |
228 | * Note: the caller must hold a reference to host. In case of failure, | |
229 | * this reference will be released. | |
1da177e4 | 230 | */ |
92737230 | 231 | struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
1da177e4 LT |
232 | { |
233 | struct nlm_rqst *call; | |
234 | ||
36943fa4 TM |
235 | for(;;) { |
236 | call = kzalloc(sizeof(*call), GFP_KERNEL); | |
237 | if (call != NULL) { | |
1da177e4 LT |
238 | locks_init_lock(&call->a_args.lock.fl); |
239 | locks_init_lock(&call->a_res.lock.fl); | |
92737230 | 240 | call->a_host = host; |
1da177e4 LT |
241 | return call; |
242 | } | |
36943fa4 TM |
243 | if (signalled()) |
244 | break; | |
92737230 | 245 | printk("nlm_alloc_call: failed, waiting for memory\n"); |
041e0e3b | 246 | schedule_timeout_interruptible(5*HZ); |
1da177e4 | 247 | } |
92737230 | 248 | nlm_release_host(host); |
1da177e4 LT |
249 | return NULL; |
250 | } | |
251 | ||
92737230 TM |
252 | void nlm_release_call(struct nlm_rqst *call) |
253 | { | |
254 | nlm_release_host(call->a_host); | |
255 | nlmclnt_release_lockargs(call); | |
256 | kfree(call); | |
257 | } | |
258 | ||
259 | static void nlmclnt_rpc_release(void *data) | |
260 | { | |
261 | return nlm_release_call(data); | |
262 | } | |
263 | ||
1da177e4 LT |
264 | static int nlm_wait_on_grace(wait_queue_head_t *queue) |
265 | { | |
266 | DEFINE_WAIT(wait); | |
267 | int status = -EINTR; | |
268 | ||
269 | prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); | |
270 | if (!signalled ()) { | |
271 | schedule_timeout(NLMCLNT_GRACE_WAIT); | |
3e1d1d28 | 272 | try_to_freeze(); |
1da177e4 LT |
273 | if (!signalled ()) |
274 | status = 0; | |
275 | } | |
276 | finish_wait(queue, &wait); | |
277 | return status; | |
278 | } | |
279 | ||
280 | /* | |
281 | * Generic NLM call | |
282 | */ | |
283 | static int | |
284 | nlmclnt_call(struct nlm_rqst *req, u32 proc) | |
285 | { | |
286 | struct nlm_host *host = req->a_host; | |
287 | struct rpc_clnt *clnt; | |
288 | struct nlm_args *argp = &req->a_args; | |
289 | struct nlm_res *resp = &req->a_res; | |
290 | struct rpc_message msg = { | |
291 | .rpc_argp = argp, | |
292 | .rpc_resp = resp, | |
293 | }; | |
294 | int status; | |
295 | ||
296 | dprintk("lockd: call procedure %d on %s\n", | |
297 | (int)proc, host->h_name); | |
298 | ||
299 | do { | |
300 | if (host->h_reclaiming && !argp->reclaim) | |
301 | goto in_grace_period; | |
302 | ||
303 | /* If we have no RPC client yet, create one. */ | |
304 | if ((clnt = nlm_bind_host(host)) == NULL) | |
305 | return -ENOLCK; | |
306 | msg.rpc_proc = &clnt->cl_procinfo[proc]; | |
307 | ||
308 | /* Perform the RPC call. If an error occurs, try again */ | |
309 | if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { | |
310 | dprintk("lockd: rpc_call returned error %d\n", -status); | |
311 | switch (status) { | |
312 | case -EPROTONOSUPPORT: | |
313 | status = -EINVAL; | |
314 | break; | |
315 | case -ECONNREFUSED: | |
316 | case -ETIMEDOUT: | |
317 | case -ENOTCONN: | |
318 | nlm_rebind_host(host); | |
319 | status = -EAGAIN; | |
320 | break; | |
321 | case -ERESTARTSYS: | |
322 | return signalled () ? -EINTR : status; | |
323 | default: | |
324 | break; | |
325 | } | |
326 | break; | |
327 | } else | |
328 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
329 | dprintk("lockd: server in grace period\n"); | |
330 | if (argp->reclaim) { | |
331 | printk(KERN_WARNING | |
332 | "lockd: spurious grace period reject?!\n"); | |
333 | return -ENOLCK; | |
334 | } | |
335 | } else { | |
336 | if (!argp->reclaim) { | |
337 | /* We appear to be out of the grace period */ | |
338 | wake_up_all(&host->h_gracewait); | |
339 | } | |
340 | dprintk("lockd: server returns status %d\n", resp->status); | |
341 | return 0; /* Okay, call complete */ | |
342 | } | |
343 | ||
344 | in_grace_period: | |
345 | /* | |
346 | * The server has rebooted and appears to be in the grace | |
347 | * period during which locks are only allowed to be | |
348 | * reclaimed. | |
349 | * We can only back off and try again later. | |
350 | */ | |
351 | status = nlm_wait_on_grace(&host->h_gracewait); | |
352 | } while (status == 0); | |
353 | ||
354 | return status; | |
355 | } | |
356 | ||
357 | /* | |
358 | * Generic NLM call, async version. | |
359 | */ | |
d4716624 | 360 | static int __nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
1da177e4 LT |
361 | { |
362 | struct nlm_host *host = req->a_host; | |
363 | struct rpc_clnt *clnt; | |
92737230 | 364 | int status = -ENOLCK; |
1da177e4 LT |
365 | |
366 | dprintk("lockd: call procedure %d on %s (async)\n", | |
367 | (int)proc, host->h_name); | |
368 | ||
369 | /* If we have no RPC client yet, create one. */ | |
92737230 TM |
370 | clnt = nlm_bind_host(host); |
371 | if (clnt == NULL) | |
372 | goto out_err; | |
d4716624 | 373 | msg->rpc_proc = &clnt->cl_procinfo[proc]; |
1da177e4 | 374 | |
1da177e4 | 375 | /* bootstrap and kick off the async RPC call */ |
d4716624 | 376 | status = rpc_call_async(clnt, msg, RPC_TASK_ASYNC, tk_ops, req); |
92737230 TM |
377 | if (status == 0) |
378 | return 0; | |
379 | out_err: | |
380 | nlm_release_call(req); | |
1da177e4 LT |
381 | return status; |
382 | } | |
383 | ||
d4716624 TM |
384 | int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
385 | { | |
386 | struct rpc_message msg = { | |
387 | .rpc_argp = &req->a_args, | |
388 | .rpc_resp = &req->a_res, | |
389 | }; | |
390 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
391 | } | |
392 | ||
393 | int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) | |
394 | { | |
395 | struct rpc_message msg = { | |
396 | .rpc_argp = &req->a_res, | |
397 | }; | |
398 | return __nlm_async_call(req, proc, &msg, tk_ops); | |
399 | } | |
400 | ||
1da177e4 LT |
401 | /* |
402 | * TEST for the presence of a conflicting lock | |
403 | */ | |
404 | static int | |
405 | nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) | |
406 | { | |
407 | int status; | |
408 | ||
409 | status = nlmclnt_call(req, NLMPROC_TEST); | |
1da177e4 | 410 | if (status < 0) |
92737230 | 411 | goto out; |
1da177e4 | 412 | |
92737230 TM |
413 | switch (req->a_res.status) { |
414 | case NLM_LCK_GRANTED: | |
415 | fl->fl_type = F_UNLCK; | |
416 | break; | |
417 | case NLM_LCK_DENIED: | |
418 | /* | |
419 | * Report the conflicting lock back to the application. | |
420 | */ | |
421 | fl->fl_start = req->a_res.lock.fl.fl_start; | |
422 | fl->fl_end = req->a_res.lock.fl.fl_start; | |
423 | fl->fl_type = req->a_res.lock.fl.fl_type; | |
424 | fl->fl_pid = 0; | |
425 | break; | |
426 | default: | |
427 | status = nlm_stat_to_errno(req->a_res.status); | |
1da177e4 | 428 | } |
92737230 TM |
429 | out: |
430 | nlm_release_call(req); | |
431 | return status; | |
1da177e4 LT |
432 | } |
433 | ||
434 | static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) | |
435 | { | |
4c060b53 TM |
436 | new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state; |
437 | new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner); | |
438 | list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted); | |
1da177e4 LT |
439 | } |
440 | ||
441 | static void nlmclnt_locks_release_private(struct file_lock *fl) | |
442 | { | |
4c060b53 | 443 | list_del(&fl->fl_u.nfs_fl.list); |
1da177e4 | 444 | nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
1da177e4 LT |
445 | } |
446 | ||
447 | static struct file_lock_operations nlmclnt_lock_ops = { | |
448 | .fl_copy_lock = nlmclnt_locks_copy_lock, | |
449 | .fl_release_private = nlmclnt_locks_release_private, | |
450 | }; | |
451 | ||
452 | static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host) | |
453 | { | |
454 | BUG_ON(fl->fl_ops != NULL); | |
455 | fl->fl_u.nfs_fl.state = 0; | |
1da177e4 | 456 | fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
4c060b53 | 457 | INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
1da177e4 LT |
458 | fl->fl_ops = &nlmclnt_lock_ops; |
459 | } | |
460 | ||
9b073574 | 461 | static int do_vfs_lock(struct file_lock *fl) |
1da177e4 LT |
462 | { |
463 | int res = 0; | |
464 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { | |
465 | case FL_POSIX: | |
466 | res = posix_lock_file_wait(fl->fl_file, fl); | |
467 | break; | |
468 | case FL_FLOCK: | |
469 | res = flock_lock_file_wait(fl->fl_file, fl); | |
470 | break; | |
471 | default: | |
472 | BUG(); | |
473 | } | |
9b073574 | 474 | return res; |
1da177e4 LT |
475 | } |
476 | ||
477 | /* | |
478 | * LOCK: Try to create a lock | |
479 | * | |
480 | * Programmer Harassment Alert | |
481 | * | |
482 | * When given a blocking lock request in a sync RPC call, the HPUX lockd | |
483 | * will faithfully return LCK_BLOCKED but never cares to notify us when | |
484 | * the lock could be granted. This way, our local process could hang | |
485 | * around forever waiting for the callback. | |
486 | * | |
487 | * Solution A: Implement busy-waiting | |
488 | * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES}) | |
489 | * | |
490 | * For now I am implementing solution A, because I hate the idea of | |
491 | * re-implementing lockd for a third time in two months. The async | |
492 | * calls shouldn't be too hard to do, however. | |
493 | * | |
494 | * This is one of the lovely things about standards in the NFS area: | |
495 | * they're so soft and squishy you can't really blame HP for doing this. | |
496 | */ | |
497 | static int | |
498 | nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) | |
499 | { | |
500 | struct nlm_host *host = req->a_host; | |
501 | struct nlm_res *resp = &req->a_res; | |
3a649b88 | 502 | struct nlm_wait *block = NULL; |
01c3b861 | 503 | unsigned char fl_flags = fl->fl_flags; |
3a649b88 | 504 | int status = -ENOLCK; |
1da177e4 | 505 | |
977faf39 | 506 | if (nsm_monitor(host) < 0) { |
1da177e4 LT |
507 | printk(KERN_NOTICE "lockd: failed to monitor %s\n", |
508 | host->h_name); | |
1da177e4 LT |
509 | goto out; |
510 | } | |
01c3b861 TM |
511 | fl->fl_flags |= FL_ACCESS; |
512 | status = do_vfs_lock(fl); | |
513 | if (status < 0) | |
514 | goto out; | |
1da177e4 | 515 | |
3a649b88 | 516 | block = nlmclnt_prepare_block(host, fl); |
28df955a | 517 | again: |
ecdbf769 | 518 | for(;;) { |
28df955a TM |
519 | /* Reboot protection */ |
520 | fl->fl_u.nfs_fl.state = host->h_state; | |
ecdbf769 TM |
521 | status = nlmclnt_call(req, NLMPROC_LOCK); |
522 | if (status < 0) | |
523 | goto out_unblock; | |
3a649b88 | 524 | if (!req->a_args.block) |
ecdbf769 | 525 | break; |
ecdbf769 TM |
526 | /* Did a reclaimer thread notify us of a server reboot? */ |
527 | if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) | |
528 | continue; | |
529 | if (resp->status != NLM_LCK_BLOCKED) | |
530 | break; | |
3a649b88 TM |
531 | /* Wait on an NLM blocking lock */ |
532 | status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); | |
533 | /* if we were interrupted. Send a CANCEL request to the server | |
ecdbf769 TM |
534 | * and exit |
535 | */ | |
3a649b88 TM |
536 | if (status < 0) |
537 | goto out_unblock; | |
538 | if (resp->status != NLM_LCK_BLOCKED) | |
539 | break; | |
ecdbf769 | 540 | } |
1da177e4 LT |
541 | |
542 | if (resp->status == NLM_LCK_GRANTED) { | |
28df955a TM |
543 | down_read(&host->h_rwsem); |
544 | /* Check whether or not the server has rebooted */ | |
545 | if (fl->fl_u.nfs_fl.state != host->h_state) { | |
546 | up_read(&host->h_rwsem); | |
547 | goto again; | |
548 | } | |
4c060b53 | 549 | /* Ensure the resulting lock will get added to granted list */ |
01c3b861 | 550 | fl->fl_flags = fl_flags | FL_SLEEP; |
9b073574 TM |
551 | if (do_vfs_lock(fl) < 0) |
552 | printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__); | |
28df955a | 553 | up_read(&host->h_rwsem); |
1da177e4 LT |
554 | } |
555 | status = nlm_stat_to_errno(resp->status); | |
ecdbf769 | 556 | out_unblock: |
3a649b88 | 557 | nlmclnt_finish_block(block); |
ecdbf769 TM |
558 | /* Cancel the blocked request if it is still pending */ |
559 | if (resp->status == NLM_LCK_BLOCKED) | |
16fb2425 | 560 | nlmclnt_cancel(host, req->a_args.block, fl); |
1da177e4 | 561 | out: |
92737230 | 562 | nlm_release_call(req); |
01c3b861 | 563 | fl->fl_flags = fl_flags; |
1da177e4 LT |
564 | return status; |
565 | } | |
566 | ||
567 | /* | |
568 | * RECLAIM: Try to reclaim a lock | |
569 | */ | |
570 | int | |
571 | nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl) | |
572 | { | |
573 | struct nlm_rqst reqst, *req; | |
574 | int status; | |
575 | ||
576 | req = &reqst; | |
577 | memset(req, 0, sizeof(*req)); | |
578 | locks_init_lock(&req->a_args.lock.fl); | |
579 | locks_init_lock(&req->a_res.lock.fl); | |
580 | req->a_host = host; | |
581 | req->a_flags = 0; | |
582 | ||
583 | /* Set up the argument struct */ | |
584 | nlmclnt_setlockargs(req, fl); | |
585 | req->a_args.reclaim = 1; | |
586 | ||
587 | if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0 | |
588 | && req->a_res.status == NLM_LCK_GRANTED) | |
589 | return 0; | |
590 | ||
591 | printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " | |
592 | "(errno %d, status %d)\n", fl->fl_pid, | |
593 | status, req->a_res.status); | |
594 | ||
595 | /* | |
596 | * FIXME: This is a serious failure. We can | |
597 | * | |
598 | * a. Ignore the problem | |
599 | * b. Send the owning process some signal (Linux doesn't have | |
600 | * SIGLOST, though...) | |
601 | * c. Retry the operation | |
602 | * | |
603 | * Until someone comes up with a simple implementation | |
604 | * for b or c, I'll choose option a. | |
605 | */ | |
606 | ||
607 | return -ENOLCK; | |
608 | } | |
609 | ||
610 | /* | |
611 | * UNLOCK: remove an existing lock | |
612 | */ | |
613 | static int | |
614 | nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) | |
615 | { | |
28df955a | 616 | struct nlm_host *host = req->a_host; |
1da177e4 | 617 | struct nlm_res *resp = &req->a_res; |
9b073574 | 618 | int status = 0; |
1da177e4 | 619 | |
30f4e20a TM |
620 | /* |
621 | * Note: the server is supposed to either grant us the unlock | |
622 | * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either | |
623 | * case, we want to unlock. | |
624 | */ | |
9b073574 | 625 | fl->fl_flags |= FL_EXISTS; |
28df955a | 626 | down_read(&host->h_rwsem); |
9b073574 TM |
627 | if (do_vfs_lock(fl) == -ENOENT) { |
628 | up_read(&host->h_rwsem); | |
629 | goto out; | |
630 | } | |
28df955a | 631 | up_read(&host->h_rwsem); |
30f4e20a | 632 | |
92737230 TM |
633 | if (req->a_flags & RPC_TASK_ASYNC) |
634 | return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); | |
1da177e4 LT |
635 | |
636 | status = nlmclnt_call(req, NLMPROC_UNLOCK); | |
1da177e4 | 637 | if (status < 0) |
92737230 | 638 | goto out; |
1da177e4 | 639 | |
1da177e4 | 640 | if (resp->status == NLM_LCK_GRANTED) |
92737230 | 641 | goto out; |
1da177e4 LT |
642 | |
643 | if (resp->status != NLM_LCK_DENIED_NOLOCKS) | |
644 | printk("lockd: unexpected unlock status: %d\n", resp->status); | |
1da177e4 | 645 | /* What to do now? I'm out of my depth... */ |
92737230 TM |
646 | status = -ENOLCK; |
647 | out: | |
648 | nlm_release_call(req); | |
649 | return status; | |
1da177e4 LT |
650 | } |
651 | ||
963d8fe5 | 652 | static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4 | 653 | { |
963d8fe5 | 654 | struct nlm_rqst *req = data; |
1da177e4 LT |
655 | int status = req->a_res.status; |
656 | ||
657 | if (RPC_ASSASSINATED(task)) | |
658 | goto die; | |
659 | ||
660 | if (task->tk_status < 0) { | |
661 | dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status); | |
662 | goto retry_rebind; | |
663 | } | |
664 | if (status == NLM_LCK_DENIED_GRACE_PERIOD) { | |
665 | rpc_delay(task, NLMCLNT_GRACE_WAIT); | |
666 | goto retry_unlock; | |
667 | } | |
668 | if (status != NLM_LCK_GRANTED) | |
669 | printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status); | |
670 | die: | |
1da177e4 LT |
671 | return; |
672 | retry_rebind: | |
673 | nlm_rebind_host(req->a_host); | |
674 | retry_unlock: | |
675 | rpc_restart_call(task); | |
676 | } | |
677 | ||
963d8fe5 TM |
678 | static const struct rpc_call_ops nlmclnt_unlock_ops = { |
679 | .rpc_call_done = nlmclnt_unlock_callback, | |
92737230 | 680 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
681 | }; |
682 | ||
1da177e4 LT |
683 | /* |
684 | * Cancel a blocked lock request. | |
685 | * We always use an async RPC call for this in order not to hang a | |
686 | * process that has been Ctrl-C'ed. | |
687 | */ | |
16fb2425 | 688 | static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4 LT |
689 | { |
690 | struct nlm_rqst *req; | |
691 | unsigned long flags; | |
692 | sigset_t oldset; | |
693 | int status; | |
694 | ||
695 | /* Block all signals while setting up call */ | |
696 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
697 | oldset = current->blocked; | |
698 | sigfillset(¤t->blocked); | |
699 | recalc_sigpending(); | |
700 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
701 | ||
92737230 | 702 | req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4 LT |
703 | if (!req) |
704 | return -ENOMEM; | |
1da177e4 LT |
705 | req->a_flags = RPC_TASK_ASYNC; |
706 | ||
707 | nlmclnt_setlockargs(req, fl); | |
16fb2425 | 708 | req->a_args.block = block; |
1da177e4 | 709 | |
92737230 | 710 | status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
1da177e4 LT |
711 | |
712 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
713 | current->blocked = oldset; | |
714 | recalc_sigpending(); | |
715 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
716 | ||
717 | return status; | |
718 | } | |
719 | ||
963d8fe5 | 720 | static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4 | 721 | { |
963d8fe5 | 722 | struct nlm_rqst *req = data; |
1da177e4 LT |
723 | |
724 | if (RPC_ASSASSINATED(task)) | |
725 | goto die; | |
726 | ||
727 | if (task->tk_status < 0) { | |
728 | dprintk("lockd: CANCEL call error %d, retrying.\n", | |
729 | task->tk_status); | |
730 | goto retry_cancel; | |
731 | } | |
732 | ||
c041b5ff | 733 | dprintk("lockd: cancel status %u (task %u)\n", |
1da177e4 LT |
734 | req->a_res.status, task->tk_pid); |
735 | ||
736 | switch (req->a_res.status) { | |
737 | case NLM_LCK_GRANTED: | |
738 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
35576cba | 739 | case NLM_LCK_DENIED: |
1da177e4 LT |
740 | /* Everything's good */ |
741 | break; | |
742 | case NLM_LCK_DENIED_NOLOCKS: | |
743 | dprintk("lockd: CANCEL failed (server has no locks)\n"); | |
744 | goto retry_cancel; | |
745 | default: | |
746 | printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n", | |
747 | req->a_res.status); | |
748 | } | |
749 | ||
750 | die: | |
1da177e4 LT |
751 | return; |
752 | ||
753 | retry_cancel: | |
aaaa9942 TM |
754 | /* Don't ever retry more than 3 times */ |
755 | if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) | |
756 | goto die; | |
1da177e4 LT |
757 | nlm_rebind_host(req->a_host); |
758 | rpc_restart_call(task); | |
759 | rpc_delay(task, 30 * HZ); | |
760 | } | |
761 | ||
963d8fe5 TM |
762 | static const struct rpc_call_ops nlmclnt_cancel_ops = { |
763 | .rpc_call_done = nlmclnt_cancel_callback, | |
92737230 | 764 | .rpc_release = nlmclnt_rpc_release, |
963d8fe5 TM |
765 | }; |
766 | ||
1da177e4 LT |
767 | /* |
768 | * Convert an NLM status code to a generic kernel errno | |
769 | */ | |
770 | static int | |
771 | nlm_stat_to_errno(u32 status) | |
772 | { | |
773 | switch(status) { | |
774 | case NLM_LCK_GRANTED: | |
775 | return 0; | |
776 | case NLM_LCK_DENIED: | |
777 | return -EAGAIN; | |
778 | case NLM_LCK_DENIED_NOLOCKS: | |
779 | case NLM_LCK_DENIED_GRACE_PERIOD: | |
780 | return -ENOLCK; | |
781 | case NLM_LCK_BLOCKED: | |
782 | printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n"); | |
783 | return -ENOLCK; | |
784 | #ifdef CONFIG_LOCKD_V4 | |
785 | case NLM_DEADLCK: | |
786 | return -EDEADLK; | |
787 | case NLM_ROFS: | |
788 | return -EROFS; | |
789 | case NLM_STALE_FH: | |
790 | return -ESTALE; | |
791 | case NLM_FBIG: | |
792 | return -EOVERFLOW; | |
793 | case NLM_FAILED: | |
794 | return -ENOLCK; | |
795 | #endif | |
796 | } | |
797 | printk(KERN_NOTICE "lockd: unexpected server status %d\n", status); | |
798 | return -ENOLCK; | |
799 | } |