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597d0cae DT |
1 | /* |
2 | * Copyright (C) 2006 Red Hat, Inc. All rights reserved. | |
3 | * | |
4 | * This copyrighted material is made available to anyone wishing to use, | |
5 | * modify, copy, or redistribute it subject to the terms and conditions | |
6 | * of the GNU General Public License v.2. | |
7 | */ | |
8 | ||
9 | #include <linux/miscdevice.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/wait.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/poll.h> | |
16 | #include <linux/signal.h> | |
17 | #include <linux/spinlock.h> | |
18 | #include <linux/dlm.h> | |
19 | #include <linux/dlm_device.h> | |
20 | ||
21 | #include "dlm_internal.h" | |
22 | #include "lockspace.h" | |
23 | #include "lock.h" | |
24 | #include "lvb_table.h" | |
25 | ||
26 | static const char *name_prefix="dlm"; | |
27 | static struct miscdevice ctl_device; | |
28 | static struct file_operations device_fops; | |
29 | ||
30 | #ifdef CONFIG_COMPAT | |
31 | ||
32 | struct dlm_lock_params32 { | |
33 | __u8 mode; | |
34 | __u8 namelen; | |
35 | __u16 flags; | |
36 | __u32 lkid; | |
37 | __u32 parent; | |
38 | ||
39 | __u32 castparam; | |
40 | __u32 castaddr; | |
41 | __u32 bastparam; | |
42 | __u32 bastaddr; | |
43 | __u32 lksb; | |
44 | ||
45 | char lvb[DLM_USER_LVB_LEN]; | |
46 | char name[0]; | |
47 | }; | |
48 | ||
49 | struct dlm_write_request32 { | |
50 | __u32 version[3]; | |
51 | __u8 cmd; | |
52 | __u8 is64bit; | |
53 | __u8 unused[2]; | |
54 | ||
55 | union { | |
56 | struct dlm_lock_params32 lock; | |
57 | struct dlm_lspace_params lspace; | |
58 | } i; | |
59 | }; | |
60 | ||
61 | struct dlm_lksb32 { | |
62 | __u32 sb_status; | |
63 | __u32 sb_lkid; | |
64 | __u8 sb_flags; | |
65 | __u32 sb_lvbptr; | |
66 | }; | |
67 | ||
68 | struct dlm_lock_result32 { | |
69 | __u32 length; | |
70 | __u32 user_astaddr; | |
71 | __u32 user_astparam; | |
72 | __u32 user_lksb; | |
73 | struct dlm_lksb32 lksb; | |
74 | __u8 bast_mode; | |
75 | __u8 unused[3]; | |
76 | /* Offsets may be zero if no data is present */ | |
77 | __u32 lvb_offset; | |
78 | }; | |
79 | ||
80 | static void compat_input(struct dlm_write_request *kb, | |
81 | struct dlm_write_request32 *kb32) | |
82 | { | |
83 | kb->version[0] = kb32->version[0]; | |
84 | kb->version[1] = kb32->version[1]; | |
85 | kb->version[2] = kb32->version[2]; | |
86 | ||
87 | kb->cmd = kb32->cmd; | |
88 | kb->is64bit = kb32->is64bit; | |
89 | if (kb->cmd == DLM_USER_CREATE_LOCKSPACE || | |
90 | kb->cmd == DLM_USER_REMOVE_LOCKSPACE) { | |
91 | kb->i.lspace.flags = kb32->i.lspace.flags; | |
92 | kb->i.lspace.minor = kb32->i.lspace.minor; | |
93 | strcpy(kb->i.lspace.name, kb32->i.lspace.name); | |
94 | } else { | |
95 | kb->i.lock.mode = kb32->i.lock.mode; | |
96 | kb->i.lock.namelen = kb32->i.lock.namelen; | |
97 | kb->i.lock.flags = kb32->i.lock.flags; | |
98 | kb->i.lock.lkid = kb32->i.lock.lkid; | |
99 | kb->i.lock.parent = kb32->i.lock.parent; | |
100 | kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam; | |
101 | kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr; | |
102 | kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam; | |
103 | kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr; | |
104 | kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb; | |
105 | memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN); | |
106 | memcpy(kb->i.lock.name, kb32->i.lock.name, kb->i.lock.namelen); | |
107 | } | |
108 | } | |
109 | ||
110 | static void compat_output(struct dlm_lock_result *res, | |
111 | struct dlm_lock_result32 *res32) | |
112 | { | |
113 | res32->length = res->length - (sizeof(struct dlm_lock_result) - | |
114 | sizeof(struct dlm_lock_result32)); | |
115 | res32->user_astaddr = (__u32)(long)res->user_astaddr; | |
116 | res32->user_astparam = (__u32)(long)res->user_astparam; | |
117 | res32->user_lksb = (__u32)(long)res->user_lksb; | |
118 | res32->bast_mode = res->bast_mode; | |
119 | ||
120 | res32->lvb_offset = res->lvb_offset; | |
121 | res32->length = res->length; | |
122 | ||
123 | res32->lksb.sb_status = res->lksb.sb_status; | |
124 | res32->lksb.sb_flags = res->lksb.sb_flags; | |
125 | res32->lksb.sb_lkid = res->lksb.sb_lkid; | |
126 | res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr; | |
127 | } | |
128 | #endif | |
129 | ||
130 | ||
131 | void dlm_user_add_ast(struct dlm_lkb *lkb, int type) | |
132 | { | |
133 | struct dlm_ls *ls; | |
134 | struct dlm_user_args *ua; | |
135 | struct dlm_user_proc *proc; | |
136 | ||
137 | /* dlm_clear_proc_locks() sets ORPHAN/DEAD flag on each | |
138 | lkb before dealing with it. We need to check this | |
139 | flag before taking ls_clear_proc_locks mutex because if | |
140 | it's set, dlm_clear_proc_locks() holds the mutex. */ | |
141 | ||
142 | if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { | |
143 | /* log_print("user_add_ast skip1 %x", lkb->lkb_flags); */ | |
144 | return; | |
145 | } | |
146 | ||
147 | ls = lkb->lkb_resource->res_ls; | |
148 | mutex_lock(&ls->ls_clear_proc_locks); | |
149 | ||
150 | /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast | |
151 | can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed | |
152 | lkb->ua so we can't try to use it. */ | |
153 | ||
154 | if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { | |
155 | /* log_print("user_add_ast skip2 %x", lkb->lkb_flags); */ | |
156 | goto out; | |
157 | } | |
158 | ||
159 | DLM_ASSERT(lkb->lkb_astparam, dlm_print_lkb(lkb);); | |
160 | ua = (struct dlm_user_args *)lkb->lkb_astparam; | |
161 | proc = ua->proc; | |
162 | ||
163 | if (type == AST_BAST && ua->bastaddr == NULL) | |
164 | goto out; | |
165 | ||
166 | spin_lock(&proc->asts_spin); | |
167 | if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) { | |
168 | kref_get(&lkb->lkb_ref); | |
169 | list_add_tail(&lkb->lkb_astqueue, &proc->asts); | |
170 | lkb->lkb_ast_type |= type; | |
171 | wake_up_interruptible(&proc->wait); | |
172 | } | |
173 | ||
174 | /* We want to copy the lvb to userspace when the completion | |
175 | ast is read if the status is 0, the lock has an lvb and | |
176 | lvb_ops says we should. We could probably have set_lvb_lock() | |
177 | set update_user_lvb instead and not need old_mode */ | |
178 | ||
179 | if ((lkb->lkb_ast_type & AST_COMP) && | |
180 | (lkb->lkb_lksb->sb_status == 0) && | |
181 | lkb->lkb_lksb->sb_lvbptr && | |
182 | dlm_lvb_operations[ua->old_mode + 1][lkb->lkb_grmode + 1]) | |
183 | ua->update_user_lvb = 1; | |
184 | else | |
185 | ua->update_user_lvb = 0; | |
186 | ||
187 | spin_unlock(&proc->asts_spin); | |
188 | out: | |
189 | mutex_unlock(&ls->ls_clear_proc_locks); | |
190 | } | |
191 | ||
192 | static int device_user_lock(struct dlm_user_proc *proc, | |
193 | struct dlm_lock_params *params) | |
194 | { | |
195 | struct dlm_ls *ls; | |
196 | struct dlm_user_args *ua; | |
197 | int error = -ENOMEM; | |
198 | ||
199 | ls = dlm_find_lockspace_local(proc->lockspace); | |
200 | if (!ls) | |
201 | return -ENOENT; | |
202 | ||
203 | if (!params->castaddr || !params->lksb) { | |
204 | error = -EINVAL; | |
205 | goto out; | |
206 | } | |
207 | ||
208 | ua = kzalloc(sizeof(struct dlm_user_args), GFP_KERNEL); | |
209 | if (!ua) | |
210 | goto out; | |
211 | ua->proc = proc; | |
212 | ua->user_lksb = params->lksb; | |
213 | ua->castparam = params->castparam; | |
214 | ua->castaddr = params->castaddr; | |
215 | ua->bastparam = params->bastparam; | |
216 | ua->bastaddr = params->bastaddr; | |
217 | ||
218 | if (params->flags & DLM_LKF_CONVERT) | |
219 | error = dlm_user_convert(ls, ua, | |
220 | params->mode, params->flags, | |
221 | params->lkid, params->lvb); | |
222 | else { | |
223 | error = dlm_user_request(ls, ua, | |
224 | params->mode, params->flags, | |
225 | params->name, params->namelen, | |
226 | params->parent); | |
227 | if (!error) | |
228 | error = ua->lksb.sb_lkid; | |
229 | } | |
230 | out: | |
231 | dlm_put_lockspace(ls); | |
232 | return error; | |
233 | } | |
234 | ||
235 | static int device_user_unlock(struct dlm_user_proc *proc, | |
236 | struct dlm_lock_params *params) | |
237 | { | |
238 | struct dlm_ls *ls; | |
239 | struct dlm_user_args *ua; | |
240 | int error = -ENOMEM; | |
241 | ||
242 | ls = dlm_find_lockspace_local(proc->lockspace); | |
243 | if (!ls) | |
244 | return -ENOENT; | |
245 | ||
246 | ua = kzalloc(sizeof(struct dlm_user_args), GFP_KERNEL); | |
247 | if (!ua) | |
248 | goto out; | |
249 | ua->proc = proc; | |
250 | ua->user_lksb = params->lksb; | |
251 | ua->castparam = params->castparam; | |
252 | ua->castaddr = params->castaddr; | |
253 | ||
254 | if (params->flags & DLM_LKF_CANCEL) | |
255 | error = dlm_user_cancel(ls, ua, params->flags, params->lkid); | |
256 | else | |
257 | error = dlm_user_unlock(ls, ua, params->flags, params->lkid, | |
258 | params->lvb); | |
259 | out: | |
260 | dlm_put_lockspace(ls); | |
261 | return error; | |
262 | } | |
263 | ||
264 | static int device_create_lockspace(struct dlm_lspace_params *params) | |
265 | { | |
266 | dlm_lockspace_t *lockspace; | |
267 | struct dlm_ls *ls; | |
268 | int error, len; | |
269 | ||
270 | if (!capable(CAP_SYS_ADMIN)) | |
271 | return -EPERM; | |
272 | ||
273 | error = dlm_new_lockspace(params->name, strlen(params->name), | |
274 | &lockspace, 0, DLM_USER_LVB_LEN); | |
275 | if (error) | |
276 | return error; | |
277 | ||
278 | ls = dlm_find_lockspace_local(lockspace); | |
279 | if (!ls) | |
280 | return -ENOENT; | |
281 | ||
282 | error = -ENOMEM; | |
283 | len = strlen(params->name) + strlen(name_prefix) + 2; | |
284 | ls->ls_device.name = kzalloc(len, GFP_KERNEL); | |
285 | if (!ls->ls_device.name) | |
286 | goto fail; | |
287 | snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix, | |
288 | params->name); | |
289 | ls->ls_device.fops = &device_fops; | |
290 | ls->ls_device.minor = MISC_DYNAMIC_MINOR; | |
291 | ||
292 | error = misc_register(&ls->ls_device); | |
293 | if (error) { | |
294 | kfree(ls->ls_device.name); | |
295 | goto fail; | |
296 | } | |
297 | ||
298 | error = ls->ls_device.minor; | |
299 | dlm_put_lockspace(ls); | |
300 | return error; | |
301 | ||
302 | fail: | |
303 | dlm_put_lockspace(ls); | |
304 | dlm_release_lockspace(lockspace, 0); | |
305 | return error; | |
306 | } | |
307 | ||
308 | static int device_remove_lockspace(struct dlm_lspace_params *params) | |
309 | { | |
310 | dlm_lockspace_t *lockspace; | |
311 | struct dlm_ls *ls; | |
312 | int error; | |
313 | ||
314 | if (!capable(CAP_SYS_ADMIN)) | |
315 | return -EPERM; | |
316 | ||
317 | ls = dlm_find_lockspace_device(params->minor); | |
318 | if (!ls) | |
319 | return -ENOENT; | |
320 | ||
321 | error = misc_deregister(&ls->ls_device); | |
322 | if (error) { | |
323 | dlm_put_lockspace(ls); | |
324 | goto out; | |
325 | } | |
326 | kfree(ls->ls_device.name); | |
327 | ||
328 | lockspace = ls->ls_local_handle; | |
329 | ||
330 | /* dlm_release_lockspace waits for references to go to zero, | |
331 | so all processes will need to close their device for the ls | |
332 | before the release will procede */ | |
333 | ||
334 | dlm_put_lockspace(ls); | |
335 | error = dlm_release_lockspace(lockspace, 0); | |
336 | out: | |
337 | return error; | |
338 | } | |
339 | ||
340 | /* Check the user's version matches ours */ | |
341 | static int check_version(struct dlm_write_request *req) | |
342 | { | |
343 | if (req->version[0] != DLM_DEVICE_VERSION_MAJOR || | |
344 | (req->version[0] == DLM_DEVICE_VERSION_MAJOR && | |
345 | req->version[1] > DLM_DEVICE_VERSION_MINOR)) { | |
346 | ||
347 | printk(KERN_DEBUG "dlm: process %s (%d) version mismatch " | |
348 | "user (%d.%d.%d) kernel (%d.%d.%d)\n", | |
349 | current->comm, | |
350 | current->pid, | |
351 | req->version[0], | |
352 | req->version[1], | |
353 | req->version[2], | |
354 | DLM_DEVICE_VERSION_MAJOR, | |
355 | DLM_DEVICE_VERSION_MINOR, | |
356 | DLM_DEVICE_VERSION_PATCH); | |
357 | return -EINVAL; | |
358 | } | |
359 | return 0; | |
360 | } | |
361 | ||
362 | /* | |
363 | * device_write | |
364 | * | |
365 | * device_user_lock | |
366 | * dlm_user_request -> request_lock | |
367 | * dlm_user_convert -> convert_lock | |
368 | * | |
369 | * device_user_unlock | |
370 | * dlm_user_unlock -> unlock_lock | |
371 | * dlm_user_cancel -> cancel_lock | |
372 | * | |
373 | * device_create_lockspace | |
374 | * dlm_new_lockspace | |
375 | * | |
376 | * device_remove_lockspace | |
377 | * dlm_release_lockspace | |
378 | */ | |
379 | ||
380 | /* a write to a lockspace device is a lock or unlock request, a write | |
381 | to the control device is to create/remove a lockspace */ | |
382 | ||
383 | static ssize_t device_write(struct file *file, const char __user *buf, | |
384 | size_t count, loff_t *ppos) | |
385 | { | |
386 | struct dlm_user_proc *proc = file->private_data; | |
387 | struct dlm_write_request *kbuf; | |
388 | sigset_t tmpsig, allsigs; | |
389 | int error; | |
390 | ||
391 | #ifdef CONFIG_COMPAT | |
392 | if (count < sizeof(struct dlm_write_request32)) | |
393 | #else | |
394 | if (count < sizeof(struct dlm_write_request)) | |
395 | #endif | |
396 | return -EINVAL; | |
397 | ||
398 | kbuf = kmalloc(count, GFP_KERNEL); | |
399 | if (!kbuf) | |
400 | return -ENOMEM; | |
401 | ||
402 | if (copy_from_user(kbuf, buf, count)) { | |
403 | error = -EFAULT; | |
404 | goto out_free; | |
405 | } | |
406 | ||
407 | if (check_version(kbuf)) { | |
408 | error = -EBADE; | |
409 | goto out_free; | |
410 | } | |
411 | ||
412 | #ifdef CONFIG_COMPAT | |
413 | if (!kbuf->is64bit) { | |
414 | struct dlm_write_request32 *k32buf; | |
415 | k32buf = (struct dlm_write_request32 *)kbuf; | |
416 | kbuf = kmalloc(count + (sizeof(struct dlm_write_request) - | |
417 | sizeof(struct dlm_write_request32)), GFP_KERNEL); | |
418 | if (!kbuf) | |
419 | return -ENOMEM; | |
420 | ||
421 | if (proc) | |
422 | set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); | |
423 | compat_input(kbuf, k32buf); | |
424 | kfree(k32buf); | |
425 | } | |
426 | #endif | |
427 | ||
428 | /* do we really need this? can a write happen after a close? */ | |
429 | if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) && | |
430 | test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) | |
431 | return -EINVAL; | |
432 | ||
433 | sigfillset(&allsigs); | |
434 | sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); | |
435 | ||
436 | error = -EINVAL; | |
437 | ||
438 | switch (kbuf->cmd) | |
439 | { | |
440 | case DLM_USER_LOCK: | |
441 | if (!proc) { | |
442 | log_print("no locking on control device"); | |
443 | goto out_sig; | |
444 | } | |
445 | error = device_user_lock(proc, &kbuf->i.lock); | |
446 | break; | |
447 | ||
448 | case DLM_USER_UNLOCK: | |
449 | if (!proc) { | |
450 | log_print("no locking on control device"); | |
451 | goto out_sig; | |
452 | } | |
453 | error = device_user_unlock(proc, &kbuf->i.lock); | |
454 | break; | |
455 | ||
456 | case DLM_USER_CREATE_LOCKSPACE: | |
457 | if (proc) { | |
458 | log_print("create/remove only on control device"); | |
459 | goto out_sig; | |
460 | } | |
461 | error = device_create_lockspace(&kbuf->i.lspace); | |
462 | break; | |
463 | ||
464 | case DLM_USER_REMOVE_LOCKSPACE: | |
465 | if (proc) { | |
466 | log_print("create/remove only on control device"); | |
467 | goto out_sig; | |
468 | } | |
469 | error = device_remove_lockspace(&kbuf->i.lspace); | |
470 | break; | |
471 | ||
472 | default: | |
473 | log_print("Unknown command passed to DLM device : %d\n", | |
474 | kbuf->cmd); | |
475 | } | |
476 | ||
477 | out_sig: | |
478 | sigprocmask(SIG_SETMASK, &tmpsig, NULL); | |
479 | recalc_sigpending(); | |
480 | out_free: | |
481 | kfree(kbuf); | |
482 | return error; | |
483 | } | |
484 | ||
485 | /* Every process that opens the lockspace device has its own "proc" structure | |
486 | hanging off the open file that's used to keep track of locks owned by the | |
487 | process and asts that need to be delivered to the process. */ | |
488 | ||
489 | static int device_open(struct inode *inode, struct file *file) | |
490 | { | |
491 | struct dlm_user_proc *proc; | |
492 | struct dlm_ls *ls; | |
493 | ||
494 | ls = dlm_find_lockspace_device(iminor(inode)); | |
495 | if (!ls) | |
496 | return -ENOENT; | |
497 | ||
498 | proc = kzalloc(sizeof(struct dlm_user_proc), GFP_KERNEL); | |
499 | if (!proc) { | |
500 | dlm_put_lockspace(ls); | |
501 | return -ENOMEM; | |
502 | } | |
503 | ||
504 | proc->lockspace = ls->ls_local_handle; | |
505 | INIT_LIST_HEAD(&proc->asts); | |
506 | INIT_LIST_HEAD(&proc->locks); | |
507 | spin_lock_init(&proc->asts_spin); | |
508 | spin_lock_init(&proc->locks_spin); | |
509 | init_waitqueue_head(&proc->wait); | |
510 | file->private_data = proc; | |
511 | ||
512 | return 0; | |
513 | } | |
514 | ||
515 | static int device_close(struct inode *inode, struct file *file) | |
516 | { | |
517 | struct dlm_user_proc *proc = file->private_data; | |
518 | struct dlm_ls *ls; | |
519 | sigset_t tmpsig, allsigs; | |
520 | ||
521 | ls = dlm_find_lockspace_local(proc->lockspace); | |
522 | if (!ls) | |
523 | return -ENOENT; | |
524 | ||
525 | sigfillset(&allsigs); | |
526 | sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); | |
527 | ||
528 | set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags); | |
529 | ||
530 | dlm_clear_proc_locks(ls, proc); | |
531 | ||
532 | /* at this point no more lkb's should exist for this lockspace, | |
533 | so there's no chance of dlm_user_add_ast() being called and | |
534 | looking for lkb->ua->proc */ | |
535 | ||
536 | kfree(proc); | |
537 | file->private_data = NULL; | |
538 | ||
539 | dlm_put_lockspace(ls); | |
540 | dlm_put_lockspace(ls); /* for the find in device_open() */ | |
541 | ||
542 | /* FIXME: AUTOFREE: if this ls is no longer used do | |
543 | device_remove_lockspace() */ | |
544 | ||
545 | sigprocmask(SIG_SETMASK, &tmpsig, NULL); | |
546 | recalc_sigpending(); | |
547 | ||
548 | return 0; | |
549 | } | |
550 | ||
551 | static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type, | |
552 | int bmode, char __user *buf, size_t count) | |
553 | { | |
554 | #ifdef CONFIG_COMPAT | |
555 | struct dlm_lock_result32 result32; | |
556 | #endif | |
557 | struct dlm_lock_result result; | |
558 | void *resultptr; | |
559 | int error=0; | |
560 | int len; | |
561 | int struct_len; | |
562 | ||
563 | memset(&result, 0, sizeof(struct dlm_lock_result)); | |
564 | memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb)); | |
565 | result.user_lksb = ua->user_lksb; | |
566 | ||
567 | /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated | |
568 | in a conversion unless the conversion is successful. See code | |
569 | in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though, | |
570 | notes that a new blocking AST address and parameter are set even if | |
571 | the conversion fails, so maybe we should just do that. */ | |
572 | ||
573 | if (type == AST_BAST) { | |
574 | result.user_astaddr = ua->bastaddr; | |
575 | result.user_astparam = ua->bastparam; | |
576 | result.bast_mode = bmode; | |
577 | } else { | |
578 | result.user_astaddr = ua->castaddr; | |
579 | result.user_astparam = ua->castparam; | |
580 | } | |
581 | ||
582 | #ifdef CONFIG_COMPAT | |
583 | if (compat) | |
584 | len = sizeof(struct dlm_lock_result32); | |
585 | else | |
586 | #endif | |
587 | len = sizeof(struct dlm_lock_result); | |
588 | struct_len = len; | |
589 | ||
590 | /* copy lvb to userspace if there is one, it's been updated, and | |
591 | the user buffer has space for it */ | |
592 | ||
593 | if (ua->update_user_lvb && ua->lksb.sb_lvbptr && | |
594 | count >= len + DLM_USER_LVB_LEN) { | |
595 | if (copy_to_user(buf+len, ua->lksb.sb_lvbptr, | |
596 | DLM_USER_LVB_LEN)) { | |
597 | error = -EFAULT; | |
598 | goto out; | |
599 | } | |
600 | ||
601 | result.lvb_offset = len; | |
602 | len += DLM_USER_LVB_LEN; | |
603 | } | |
604 | ||
605 | result.length = len; | |
606 | resultptr = &result; | |
607 | #ifdef CONFIG_COMPAT | |
608 | if (compat) { | |
609 | compat_output(&result, &result32); | |
610 | resultptr = &result32; | |
611 | } | |
612 | #endif | |
613 | ||
614 | if (copy_to_user(buf, resultptr, struct_len)) | |
615 | error = -EFAULT; | |
616 | else | |
617 | error = len; | |
618 | out: | |
619 | return error; | |
620 | } | |
621 | ||
622 | /* a read returns a single ast described in a struct dlm_lock_result */ | |
623 | ||
624 | static ssize_t device_read(struct file *file, char __user *buf, size_t count, | |
625 | loff_t *ppos) | |
626 | { | |
627 | struct dlm_user_proc *proc = file->private_data; | |
628 | struct dlm_lkb *lkb; | |
629 | struct dlm_user_args *ua; | |
630 | DECLARE_WAITQUEUE(wait, current); | |
631 | int error, type=0, bmode=0, removed = 0; | |
632 | ||
633 | #ifdef CONFIG_COMPAT | |
634 | if (count < sizeof(struct dlm_lock_result32)) | |
635 | #else | |
636 | if (count < sizeof(struct dlm_lock_result)) | |
637 | #endif | |
638 | return -EINVAL; | |
639 | ||
640 | /* do we really need this? can a read happen after a close? */ | |
641 | if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) | |
642 | return -EINVAL; | |
643 | ||
644 | spin_lock(&proc->asts_spin); | |
645 | if (list_empty(&proc->asts)) { | |
646 | if (file->f_flags & O_NONBLOCK) { | |
647 | spin_unlock(&proc->asts_spin); | |
648 | return -EAGAIN; | |
649 | } | |
650 | ||
651 | add_wait_queue(&proc->wait, &wait); | |
652 | ||
653 | repeat: | |
654 | set_current_state(TASK_INTERRUPTIBLE); | |
655 | if (list_empty(&proc->asts) && !signal_pending(current)) { | |
656 | spin_unlock(&proc->asts_spin); | |
657 | schedule(); | |
658 | spin_lock(&proc->asts_spin); | |
659 | goto repeat; | |
660 | } | |
661 | set_current_state(TASK_RUNNING); | |
662 | remove_wait_queue(&proc->wait, &wait); | |
663 | ||
664 | if (signal_pending(current)) { | |
665 | spin_unlock(&proc->asts_spin); | |
666 | return -ERESTARTSYS; | |
667 | } | |
668 | } | |
669 | ||
670 | if (list_empty(&proc->asts)) { | |
671 | spin_unlock(&proc->asts_spin); | |
672 | return -EAGAIN; | |
673 | } | |
674 | ||
675 | /* there may be both completion and blocking asts to return for | |
676 | the lkb, don't remove lkb from asts list unless no asts remain */ | |
677 | ||
678 | lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue); | |
679 | ||
680 | if (lkb->lkb_ast_type & AST_COMP) { | |
681 | lkb->lkb_ast_type &= ~AST_COMP; | |
682 | type = AST_COMP; | |
683 | } else if (lkb->lkb_ast_type & AST_BAST) { | |
684 | lkb->lkb_ast_type &= ~AST_BAST; | |
685 | type = AST_BAST; | |
686 | bmode = lkb->lkb_bastmode; | |
687 | } | |
688 | ||
689 | if (!lkb->lkb_ast_type) { | |
690 | list_del(&lkb->lkb_astqueue); | |
691 | removed = 1; | |
692 | } | |
693 | spin_unlock(&proc->asts_spin); | |
694 | ||
695 | ua = (struct dlm_user_args *)lkb->lkb_astparam; | |
696 | error = copy_result_to_user(ua, | |
697 | test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), | |
698 | type, bmode, buf, count); | |
699 | ||
700 | /* removes reference for the proc->asts lists added by | |
701 | dlm_user_add_ast() and may result in the lkb being freed */ | |
702 | if (removed) | |
703 | dlm_put_lkb(lkb); | |
704 | ||
705 | return error; | |
706 | } | |
707 | ||
708 | static unsigned int device_poll(struct file *file, poll_table *wait) | |
709 | { | |
710 | struct dlm_user_proc *proc = file->private_data; | |
711 | ||
712 | poll_wait(file, &proc->wait, wait); | |
713 | ||
714 | spin_lock(&proc->asts_spin); | |
715 | if (!list_empty(&proc->asts)) { | |
716 | spin_unlock(&proc->asts_spin); | |
717 | return POLLIN | POLLRDNORM; | |
718 | } | |
719 | spin_unlock(&proc->asts_spin); | |
720 | return 0; | |
721 | } | |
722 | ||
723 | static int ctl_device_open(struct inode *inode, struct file *file) | |
724 | { | |
725 | file->private_data = NULL; | |
726 | return 0; | |
727 | } | |
728 | ||
729 | static int ctl_device_close(struct inode *inode, struct file *file) | |
730 | { | |
731 | return 0; | |
732 | } | |
733 | ||
734 | static struct file_operations device_fops = { | |
735 | .open = device_open, | |
736 | .release = device_close, | |
737 | .read = device_read, | |
738 | .write = device_write, | |
739 | .poll = device_poll, | |
740 | .owner = THIS_MODULE, | |
741 | }; | |
742 | ||
743 | static struct file_operations ctl_device_fops = { | |
744 | .open = ctl_device_open, | |
745 | .release = ctl_device_close, | |
746 | .write = device_write, | |
747 | .owner = THIS_MODULE, | |
748 | }; | |
749 | ||
750 | int dlm_user_init(void) | |
751 | { | |
752 | int error; | |
753 | ||
754 | ctl_device.name = "dlm-control"; | |
755 | ctl_device.fops = &ctl_device_fops; | |
756 | ctl_device.minor = MISC_DYNAMIC_MINOR; | |
757 | ||
758 | error = misc_register(&ctl_device); | |
759 | if (error) | |
760 | log_print("misc_register failed for control device"); | |
761 | ||
762 | return error; | |
763 | } | |
764 | ||
765 | void dlm_user_exit(void) | |
766 | { | |
767 | misc_deregister(&ctl_device); | |
768 | } | |
769 |