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RT-AC56 3.0.0.4.374.37 core
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / fs / dlm / user.c
blob4a42fb4ffe3e783c9a144ae0b7518ddf70d7dd2f
1 /*
2 * Copyright (C) 2006-2010 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 #include <linux/slab.h>
21
22 #include "dlm_internal.h"
23 #include "lockspace.h"
24 #include "lock.h"
25 #include "lvb_table.h"
26 #include "user.h"
27
28 static const char name_prefix[] = "dlm";
29 static const struct file_operations device_fops;
30 static atomic_t dlm_monitor_opened;
31 static int dlm_monitor_unused = 1;
32
33 #ifdef CONFIG_COMPAT
34
35 struct dlm_lock_params32 {
36 __u8 mode;
37 __u8 namelen;
38 __u16 unused;
39 __u32 flags;
40 __u32 lkid;
41 __u32 parent;
42 __u64 xid;
43 __u64 timeout;
44 __u32 castparam;
45 __u32 castaddr;
46 __u32 bastparam;
47 __u32 bastaddr;
48 __u32 lksb;
49 char lvb[DLM_USER_LVB_LEN];
50 char name[0];
51 };
52
53 struct dlm_write_request32 {
54 __u32 version[3];
55 __u8 cmd;
56 __u8 is64bit;
57 __u8 unused[2];
58
59 union {
60 struct dlm_lock_params32 lock;
61 struct dlm_lspace_params lspace;
62 struct dlm_purge_params purge;
63 } i;
64 };
65
66 struct dlm_lksb32 {
67 __u32 sb_status;
68 __u32 sb_lkid;
69 __u8 sb_flags;
70 __u32 sb_lvbptr;
71 };
72
73 struct dlm_lock_result32 {
74 __u32 version[3];
75 __u32 length;
76 __u32 user_astaddr;
77 __u32 user_astparam;
78 __u32 user_lksb;
79 struct dlm_lksb32 lksb;
80 __u8 bast_mode;
81 __u8 unused[3];
82 /* Offsets may be zero if no data is present */
83 __u32 lvb_offset;
84 };
85
86 static void compat_input(struct dlm_write_request *kb,
87 struct dlm_write_request32 *kb32,
88 int namelen)
89 {
90 kb->version[0] = kb32->version[0];
91 kb->version[1] = kb32->version[1];
92 kb->version[2] = kb32->version[2];
93
94 kb->cmd = kb32->cmd;
95 kb->is64bit = kb32->is64bit;
96 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
97 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
98 kb->i.lspace.flags = kb32->i.lspace.flags;
99 kb->i.lspace.minor = kb32->i.lspace.minor;
100 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
101 } else if (kb->cmd == DLM_USER_PURGE) {
102 kb->i.purge.nodeid = kb32->i.purge.nodeid;
103 kb->i.purge.pid = kb32->i.purge.pid;
104 } else {
105 kb->i.lock.mode = kb32->i.lock.mode;
106 kb->i.lock.namelen = kb32->i.lock.namelen;
107 kb->i.lock.flags = kb32->i.lock.flags;
108 kb->i.lock.lkid = kb32->i.lock.lkid;
109 kb->i.lock.parent = kb32->i.lock.parent;
110 kb->i.lock.xid = kb32->i.lock.xid;
111 kb->i.lock.timeout = kb32->i.lock.timeout;
112 kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
113 kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
114 kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
115 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
116 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
117 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
118 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
119 }
120 }
121
122 static void compat_output(struct dlm_lock_result *res,
123 struct dlm_lock_result32 *res32)
124 {
125 res32->version[0] = res->version[0];
126 res32->version[1] = res->version[1];
127 res32->version[2] = res->version[2];
128
129 res32->user_astaddr = (__u32)(long)res->user_astaddr;
130 res32->user_astparam = (__u32)(long)res->user_astparam;
131 res32->user_lksb = (__u32)(long)res->user_lksb;
132 res32->bast_mode = res->bast_mode;
133
134 res32->lvb_offset = res->lvb_offset;
135 res32->length = res->length;
136
137 res32->lksb.sb_status = res->lksb.sb_status;
138 res32->lksb.sb_flags = res->lksb.sb_flags;
139 res32->lksb.sb_lkid = res->lksb.sb_lkid;
140 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
141 }
142 #endif
143
144 /* Figure out if this lock is at the end of its life and no longer
145 available for the application to use. The lkb still exists until
146 the final ast is read. A lock becomes EOL in three situations:
147 1. a noqueue request fails with EAGAIN
148 2. an unlock completes with EUNLOCK
149 3. a cancel of a waiting request completes with ECANCEL/EDEADLK
150 An EOL lock needs to be removed from the process's list of locks.
151 And we can't allow any new operation on an EOL lock. This is
152 not related to the lifetime of the lkb struct which is managed
153 entirely by refcount. */
154
155 static int lkb_is_endoflife(struct dlm_lkb *lkb, int sb_status, int type)
156 {
157 switch (sb_status) {
158 case -DLM_EUNLOCK:
159 return 1;
160 case -DLM_ECANCEL:
161 case -ETIMEDOUT:
162 case -EDEADLK:
163 if (lkb->lkb_grmode == DLM_LOCK_IV)
164 return 1;
165 break;
166 case -EAGAIN:
167 if (type == AST_COMP && lkb->lkb_grmode == DLM_LOCK_IV)
168 return 1;
169 break;
170 }
171 return 0;
172 }
173
174 /* we could possibly check if the cancel of an orphan has resulted in the lkb
175 being removed and then remove that lkb from the orphans list and free it */
176
177 void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int mode)
178 {
179 struct dlm_ls *ls;
180 struct dlm_user_args *ua;
181 struct dlm_user_proc *proc;
182 int eol = 0, ast_type;
183
184 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
185 return;
186
187 ls = lkb->lkb_resource->res_ls;
188 mutex_lock(&ls->ls_clear_proc_locks);
189
190 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
191 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
192 lkb->ua so we can't try to use it. This second check is necessary
193 for cases where a completion ast is received for an operation that
194 began before clear_proc_locks did its cancel/unlock. */
195
196 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
197 goto out;
198
199 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
200 ua = lkb->lkb_ua;
201 proc = ua->proc;
202
203 if (type == AST_BAST && ua->bastaddr == NULL)
204 goto out;
205
206 spin_lock(&proc->asts_spin);
207
208 ast_type = lkb->lkb_ast_type;
209 lkb->lkb_ast_type |= type;
210 if (type == AST_BAST)
211 lkb->lkb_bastmode = mode;
212 else
213 lkb->lkb_castmode = mode;
214
215 if (!ast_type) {
216 kref_get(&lkb->lkb_ref);
217 list_add_tail(&lkb->lkb_astqueue, &proc->asts);
218 lkb->lkb_ast_first = type;
219 wake_up_interruptible(&proc->wait);
220 }
221 if (type == AST_COMP && (ast_type & AST_COMP))
222 log_debug(ls, "ast overlap %x status %x %x",
223 lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags);
224
225 eol = lkb_is_endoflife(lkb, ua->lksb.sb_status, type);
226 if (eol) {
227 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
228 }
229
230 /* We want to copy the lvb to userspace when the completion
231 ast is read if the status is 0, the lock has an lvb and
232 lvb_ops says we should. We could probably have set_lvb_lock()
233 set update_user_lvb instead and not need old_mode */
234
235 if ((lkb->lkb_ast_type & AST_COMP) &&
236 (lkb->lkb_lksb->sb_status == 0) &&
237 lkb->lkb_lksb->sb_lvbptr &&
238 dlm_lvb_operations[ua->old_mode + 1][lkb->lkb_grmode + 1])
239 ua->update_user_lvb = 1;
240 else
241 ua->update_user_lvb = 0;
242
243 spin_unlock(&proc->asts_spin);
244
245 if (eol) {
246 spin_lock(&proc->locks_spin);
247 if (!list_empty(&lkb->lkb_ownqueue)) {
248 list_del_init(&lkb->lkb_ownqueue);
249 dlm_put_lkb(lkb);
250 }
251 spin_unlock(&proc->locks_spin);
252 }
253 out:
254 mutex_unlock(&ls->ls_clear_proc_locks);
255 }
256
257 static int device_user_lock(struct dlm_user_proc *proc,
258 struct dlm_lock_params *params)
259 {
260 struct dlm_ls *ls;
261 struct dlm_user_args *ua;
262 int error = -ENOMEM;
263
264 ls = dlm_find_lockspace_local(proc->lockspace);
265 if (!ls)
266 return -ENOENT;
267
268 if (!params->castaddr || !params->lksb) {
269 error = -EINVAL;
270 goto out;
271 }
272
273 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
274 if (!ua)
275 goto out;
276 ua->proc = proc;
277 ua->user_lksb = params->lksb;
278 ua->castparam = params->castparam;
279 ua->castaddr = params->castaddr;
280 ua->bastparam = params->bastparam;
281 ua->bastaddr = params->bastaddr;
282 ua->xid = params->xid;
283
284 if (params->flags & DLM_LKF_CONVERT)
285 error = dlm_user_convert(ls, ua,
286 params->mode, params->flags,
287 params->lkid, params->lvb,
288 (unsigned long) params->timeout);
289 else {
290 error = dlm_user_request(ls, ua,
291 params->mode, params->flags,
292 params->name, params->namelen,
293 (unsigned long) params->timeout);
294 if (!error)
295 error = ua->lksb.sb_lkid;
296 }
297 out:
298 dlm_put_lockspace(ls);
299 return error;
300 }
301
302 static int device_user_unlock(struct dlm_user_proc *proc,
303 struct dlm_lock_params *params)
304 {
305 struct dlm_ls *ls;
306 struct dlm_user_args *ua;
307 int error = -ENOMEM;
308
309 ls = dlm_find_lockspace_local(proc->lockspace);
310 if (!ls)
311 return -ENOENT;
312
313 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
314 if (!ua)
315 goto out;
316 ua->proc = proc;
317 ua->user_lksb = params->lksb;
318 ua->castparam = params->castparam;
319 ua->castaddr = params->castaddr;
320
321 if (params->flags & DLM_LKF_CANCEL)
322 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
323 else
324 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
325 params->lvb);
326 out:
327 dlm_put_lockspace(ls);
328 return error;
329 }
330
331 static int device_user_deadlock(struct dlm_user_proc *proc,
332 struct dlm_lock_params *params)
333 {
334 struct dlm_ls *ls;
335 int error;
336
337 ls = dlm_find_lockspace_local(proc->lockspace);
338 if (!ls)
339 return -ENOENT;
340
341 error = dlm_user_deadlock(ls, params->flags, params->lkid);
342
343 dlm_put_lockspace(ls);
344 return error;
345 }
346
347 static int dlm_device_register(struct dlm_ls *ls, char *name)
348 {
349 int error, len;
350
351 /* The device is already registered. This happens when the
352 lockspace is created multiple times from userspace. */
353 if (ls->ls_device.name)
354 return 0;
355
356 error = -ENOMEM;
357 len = strlen(name) + strlen(name_prefix) + 2;
358 ls->ls_device.name = kzalloc(len, GFP_NOFS);
359 if (!ls->ls_device.name)
360 goto fail;
361
362 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
363 name);
364 ls->ls_device.fops = &device_fops;
365 ls->ls_device.minor = MISC_DYNAMIC_MINOR;
366
367 error = misc_register(&ls->ls_device);
368 if (error) {
369 kfree(ls->ls_device.name);
370 }
371 fail:
372 return error;
373 }
374
375 int dlm_device_deregister(struct dlm_ls *ls)
376 {
377 int error;
378
379 /* The device is not registered. This happens when the lockspace
380 was never used from userspace, or when device_create_lockspace()
381 calls dlm_release_lockspace() after the register fails. */
382 if (!ls->ls_device.name)
383 return 0;
384
385 error = misc_deregister(&ls->ls_device);
386 if (!error)
387 kfree(ls->ls_device.name);
388 return error;
389 }
390
391 static int device_user_purge(struct dlm_user_proc *proc,
392 struct dlm_purge_params *params)
393 {
394 struct dlm_ls *ls;
395 int error;
396
397 ls = dlm_find_lockspace_local(proc->lockspace);
398 if (!ls)
399 return -ENOENT;
400
401 error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
402
403 dlm_put_lockspace(ls);
404 return error;
405 }
406
407 static int device_create_lockspace(struct dlm_lspace_params *params)
408 {
409 dlm_lockspace_t *lockspace;
410 struct dlm_ls *ls;
411 int error;
412
413 if (!capable(CAP_SYS_ADMIN))
414 return -EPERM;
415
416 error = dlm_new_lockspace(params->name, strlen(params->name),
417 &lockspace, params->flags, DLM_USER_LVB_LEN);
418 if (error)
419 return error;
420
421 ls = dlm_find_lockspace_local(lockspace);
422 if (!ls)
423 return -ENOENT;
424
425 error = dlm_device_register(ls, params->name);
426 dlm_put_lockspace(ls);
427
428 if (error)
429 dlm_release_lockspace(lockspace, 0);
430 else
431 error = ls->ls_device.minor;
432
433 return error;
434 }
435
436 static int device_remove_lockspace(struct dlm_lspace_params *params)
437 {
438 dlm_lockspace_t *lockspace;
439 struct dlm_ls *ls;
440 int error, force = 0;
441
442 if (!capable(CAP_SYS_ADMIN))
443 return -EPERM;
444
445 ls = dlm_find_lockspace_device(params->minor);
446 if (!ls)
447 return -ENOENT;
448
449 if (params->flags & DLM_USER_LSFLG_FORCEFREE)
450 force = 2;
451
452 lockspace = ls->ls_local_handle;
453 dlm_put_lockspace(ls);
454
455 /* The final dlm_release_lockspace waits for references to go to
456 zero, so all processes will need to close their device for the
457 ls before the release will proceed. release also calls the
458 device_deregister above. Converting a positive return value
459 from release to zero means that userspace won't know when its
460 release was the final one, but it shouldn't need to know. */
461
462 error = dlm_release_lockspace(lockspace, force);
463 if (error > 0)
464 error = 0;
465 return error;
466 }
467
468 /* Check the user's version matches ours */
469 static int check_version(struct dlm_write_request *req)
470 {
471 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
472 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
473 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
474
475 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
476 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
477 current->comm,
478 task_pid_nr(current),
479 req->version[0],
480 req->version[1],
481 req->version[2],
482 DLM_DEVICE_VERSION_MAJOR,
483 DLM_DEVICE_VERSION_MINOR,
484 DLM_DEVICE_VERSION_PATCH);
485 return -EINVAL;
486 }
487 return 0;
488 }
489
490 /*
491 * device_write
492 *
493 * device_user_lock
494 * dlm_user_request -> request_lock
495 * dlm_user_convert -> convert_lock
496 *
497 * device_user_unlock
498 * dlm_user_unlock -> unlock_lock
499 * dlm_user_cancel -> cancel_lock
500 *
501 * device_create_lockspace
502 * dlm_new_lockspace
503 *
504 * device_remove_lockspace
505 * dlm_release_lockspace
506 */
507
508 /* a write to a lockspace device is a lock or unlock request, a write
509 to the control device is to create/remove a lockspace */
510
511 static ssize_t device_write(struct file *file, const char __user *buf,
512 size_t count, loff_t *ppos)
513 {
514 struct dlm_user_proc *proc = file->private_data;
515 struct dlm_write_request *kbuf;
516 sigset_t tmpsig, allsigs;
517 int error;
518
519 #ifdef CONFIG_COMPAT
520 if (count < sizeof(struct dlm_write_request32))
521 #else
522 if (count < sizeof(struct dlm_write_request))
523 #endif
524 return -EINVAL;
525
526 kbuf = kzalloc(count + 1, GFP_NOFS);
527 if (!kbuf)
528 return -ENOMEM;
529
530 if (copy_from_user(kbuf, buf, count)) {
531 error = -EFAULT;
532 goto out_free;
533 }
534
535 if (check_version(kbuf)) {
536 error = -EBADE;
537 goto out_free;
538 }
539
540 #ifdef CONFIG_COMPAT
541 if (!kbuf->is64bit) {
542 struct dlm_write_request32 *k32buf;
543 int namelen = 0;
544
545 if (count > sizeof(struct dlm_write_request32))
546 namelen = count - sizeof(struct dlm_write_request32);
547
548 k32buf = (struct dlm_write_request32 *)kbuf;
549
550 /* add 1 after namelen so that the name string is terminated */
551 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
552 GFP_NOFS);
553 if (!kbuf) {
554 kfree(k32buf);
555 return -ENOMEM;
556 }
557
558 if (proc)
559 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
560
561 compat_input(kbuf, k32buf, namelen);
562 kfree(k32buf);
563 }
564 #endif
565
566 /* do we really need this? can a write happen after a close? */
567 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
568 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
569 error = -EINVAL;
570 goto out_free;
571 }
572
573 sigfillset(&allsigs);
574 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
575
576 error = -EINVAL;
577
578 switch (kbuf->cmd)
579 {
580 case DLM_USER_LOCK:
581 if (!proc) {
582 log_print("no locking on control device");
583 goto out_sig;
584 }
585 error = device_user_lock(proc, &kbuf->i.lock);
586 break;
587
588 case DLM_USER_UNLOCK:
589 if (!proc) {
590 log_print("no locking on control device");
591 goto out_sig;
592 }
593 error = device_user_unlock(proc, &kbuf->i.lock);
594 break;
595
596 case DLM_USER_DEADLOCK:
597 if (!proc) {
598 log_print("no locking on control device");
599 goto out_sig;
600 }
601 error = device_user_deadlock(proc, &kbuf->i.lock);
602 break;
603
604 case DLM_USER_CREATE_LOCKSPACE:
605 if (proc) {
606 log_print("create/remove only on control device");
607 goto out_sig;
608 }
609 error = device_create_lockspace(&kbuf->i.lspace);
610 break;
611
612 case DLM_USER_REMOVE_LOCKSPACE:
613 if (proc) {
614 log_print("create/remove only on control device");
615 goto out_sig;
616 }
617 error = device_remove_lockspace(&kbuf->i.lspace);
618 break;
619
620 case DLM_USER_PURGE:
621 if (!proc) {
622 log_print("no locking on control device");
623 goto out_sig;
624 }
625 error = device_user_purge(proc, &kbuf->i.purge);
626 break;
627
628 default:
629 log_print("Unknown command passed to DLM device : %d\n",
630 kbuf->cmd);
631 }
632
633 out_sig:
634 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
635 recalc_sigpending();
636 out_free:
637 kfree(kbuf);
638 return error;
639 }
640
641 /* Every process that opens the lockspace device has its own "proc" structure
642 hanging off the open file that's used to keep track of locks owned by the
643 process and asts that need to be delivered to the process. */
644
645 static int device_open(struct inode *inode, struct file *file)
646 {
647 struct dlm_user_proc *proc;
648 struct dlm_ls *ls;
649
650 ls = dlm_find_lockspace_device(iminor(inode));
651 if (!ls)
652 return -ENOENT;
653
654 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
655 if (!proc) {
656 dlm_put_lockspace(ls);
657 return -ENOMEM;
658 }
659
660 proc->lockspace = ls->ls_local_handle;
661 INIT_LIST_HEAD(&proc->asts);
662 INIT_LIST_HEAD(&proc->locks);
663 INIT_LIST_HEAD(&proc->unlocking);
664 spin_lock_init(&proc->asts_spin);
665 spin_lock_init(&proc->locks_spin);
666 init_waitqueue_head(&proc->wait);
667 file->private_data = proc;
668
669 return 0;
670 }
671
672 static int device_close(struct inode *inode, struct file *file)
673 {
674 struct dlm_user_proc *proc = file->private_data;
675 struct dlm_ls *ls;
676 sigset_t tmpsig, allsigs;
677
678 ls = dlm_find_lockspace_local(proc->lockspace);
679 if (!ls)
680 return -ENOENT;
681
682 sigfillset(&allsigs);
683 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
684
685 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
686
687 dlm_clear_proc_locks(ls, proc);
688
689 /* at this point no more lkb's should exist for this lockspace,
690 so there's no chance of dlm_user_add_ast() being called and
691 looking for lkb->ua->proc */
692
693 kfree(proc);
694 file->private_data = NULL;
695
696 dlm_put_lockspace(ls);
697 dlm_put_lockspace(ls); /* for the find in device_open() */
698
699
700 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
701 recalc_sigpending();
702
703 return 0;
704 }
705
706 static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type,
707 int mode, char __user *buf, size_t count)
708 {
709 #ifdef CONFIG_COMPAT
710 struct dlm_lock_result32 result32;
711 #endif
712 struct dlm_lock_result result;
713 void *resultptr;
714 int error=0;
715 int len;
716 int struct_len;
717
718 memset(&result, 0, sizeof(struct dlm_lock_result));
719 result.version[0] = DLM_DEVICE_VERSION_MAJOR;
720 result.version[1] = DLM_DEVICE_VERSION_MINOR;
721 result.version[2] = DLM_DEVICE_VERSION_PATCH;
722 memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb));
723 result.user_lksb = ua->user_lksb;
724
725
726 if (type == AST_BAST) {
727 result.user_astaddr = ua->bastaddr;
728 result.user_astparam = ua->bastparam;
729 result.bast_mode = mode;
730 } else {
731 result.user_astaddr = ua->castaddr;
732 result.user_astparam = ua->castparam;
733 }
734
735 #ifdef CONFIG_COMPAT
736 if (compat)
737 len = sizeof(struct dlm_lock_result32);
738 else
739 #endif
740 len = sizeof(struct dlm_lock_result);
741 struct_len = len;
742
743 /* copy lvb to userspace if there is one, it's been updated, and
744 the user buffer has space for it */
745
746 if (ua->update_user_lvb && ua->lksb.sb_lvbptr &&
747 count >= len + DLM_USER_LVB_LEN) {
748 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
749 DLM_USER_LVB_LEN)) {
750 error = -EFAULT;
751 goto out;
752 }
753
754 result.lvb_offset = len;
755 len += DLM_USER_LVB_LEN;
756 }
757
758 result.length = len;
759 resultptr = &result;
760 #ifdef CONFIG_COMPAT
761 if (compat) {
762 compat_output(&result, &result32);
763 resultptr = &result32;
764 }
765 #endif
766
767 if (copy_to_user(buf, resultptr, struct_len))
768 error = -EFAULT;
769 else
770 error = len;
771 out:
772 return error;
773 }
774
775 static int copy_version_to_user(char __user *buf, size_t count)
776 {
777 struct dlm_device_version ver;
778
779 memset(&ver, 0, sizeof(struct dlm_device_version));
780 ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
781 ver.version[1] = DLM_DEVICE_VERSION_MINOR;
782 ver.version[2] = DLM_DEVICE_VERSION_PATCH;
783
784 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
785 return -EFAULT;
786 return sizeof(struct dlm_device_version);
787 }
788
789 /* a read returns a single ast described in a struct dlm_lock_result */
790
791 static ssize_t device_read(struct file *file, char __user *buf, size_t count,
792 loff_t *ppos)
793 {
794 struct dlm_user_proc *proc = file->private_data;
795 struct dlm_lkb *lkb;
796 DECLARE_WAITQUEUE(wait, current);
797 int error = 0, removed;
798 int ret_type, ret_mode;
799 int bastmode, castmode, do_bast, do_cast;
800
801 if (count == sizeof(struct dlm_device_version)) {
802 error = copy_version_to_user(buf, count);
803 return error;
804 }
805
806 if (!proc) {
807 log_print("non-version read from control device %zu", count);
808 return -EINVAL;
809 }
810
811 #ifdef CONFIG_COMPAT
812 if (count < sizeof(struct dlm_lock_result32))
813 #else
814 if (count < sizeof(struct dlm_lock_result))
815 #endif
816 return -EINVAL;
817
818 try_another:
819
820 /* do we really need this? can a read happen after a close? */
821 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
822 return -EINVAL;
823
824 spin_lock(&proc->asts_spin);
825 if (list_empty(&proc->asts)) {
826 if (file->f_flags & O_NONBLOCK) {
827 spin_unlock(&proc->asts_spin);
828 return -EAGAIN;
829 }
830
831 add_wait_queue(&proc->wait, &wait);
832
833 repeat:
834 set_current_state(TASK_INTERRUPTIBLE);
835 if (list_empty(&proc->asts) && !signal_pending(current)) {
836 spin_unlock(&proc->asts_spin);
837 schedule();
838 spin_lock(&proc->asts_spin);
839 goto repeat;
840 }
841 set_current_state(TASK_RUNNING);
842 remove_wait_queue(&proc->wait, &wait);
843
844 if (signal_pending(current)) {
845 spin_unlock(&proc->asts_spin);
846 return -ERESTARTSYS;
847 }
848 }
849
850 /* there may be both completion and blocking asts to return for
851 the lkb, don't remove lkb from asts list unless no asts remain */
852
853 lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue);
854
855 removed = 0;
856 ret_type = 0;
857 ret_mode = 0;
858 do_bast = lkb->lkb_ast_type & AST_BAST;
859 do_cast = lkb->lkb_ast_type & AST_COMP;
860 bastmode = lkb->lkb_bastmode;
861 castmode = lkb->lkb_castmode;
862
863 /* when both are queued figure out which to do first and
864 switch first so the other goes in the next read */
865
866 if (do_cast && do_bast) {
867 if (lkb->lkb_ast_first == AST_COMP) {
868 ret_type = AST_COMP;
869 ret_mode = castmode;
870 lkb->lkb_ast_type &= ~AST_COMP;
871 lkb->lkb_ast_first = AST_BAST;
872 } else {
873 ret_type = AST_BAST;
874 ret_mode = bastmode;
875 lkb->lkb_ast_type &= ~AST_BAST;
876 lkb->lkb_ast_first = AST_COMP;
877 }
878 } else {
879 ret_type = lkb->lkb_ast_first;
880 ret_mode = (ret_type == AST_COMP) ? castmode : bastmode;
881 lkb->lkb_ast_type &= ~ret_type;
882 lkb->lkb_ast_first = 0;
883 }
884
885 /* if we're doing a bast but the bast is unnecessary, then
886 switch to do nothing or do a cast if that was needed next */
887
888 if ((ret_type == AST_BAST) &&
889 dlm_modes_compat(bastmode, lkb->lkb_castmode_done)) {
890 ret_type = 0;
891 ret_mode = 0;
892
893 if (do_cast) {
894 ret_type = AST_COMP;
895 ret_mode = castmode;
896 lkb->lkb_ast_type &= ~AST_COMP;
897 lkb->lkb_ast_first = 0;
898 }
899 }
900
901 if (lkb->lkb_ast_first != lkb->lkb_ast_type) {
902 log_print("device_read %x ast_first %x ast_type %x",
903 lkb->lkb_id, lkb->lkb_ast_first, lkb->lkb_ast_type);
904 }
905
906 if (!lkb->lkb_ast_type) {
907 list_del(&lkb->lkb_astqueue);
908 removed = 1;
909 }
910 spin_unlock(&proc->asts_spin);
911
912 if (ret_type) {
913 error = copy_result_to_user(lkb->lkb_ua,
914 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
915 ret_type, ret_mode, buf, count);
916
917 if (ret_type == AST_COMP)
918 lkb->lkb_castmode_done = castmode;
919 if (ret_type == AST_BAST)
920 lkb->lkb_bastmode_done = bastmode;
921 }
922
923 /* removes reference for the proc->asts lists added by
924 dlm_user_add_ast() and may result in the lkb being freed */
925
926 if (removed)
927 dlm_put_lkb(lkb);
928
929 /* the bast that was queued was eliminated (see unnecessary above),
930 leaving nothing to return */
931
932 if (!ret_type)
933 goto try_another;
934
935 return error;
936 }
937
938 static unsigned int device_poll(struct file *file, poll_table *wait)
939 {
940 struct dlm_user_proc *proc = file->private_data;
941
942 poll_wait(file, &proc->wait, wait);
943
944 spin_lock(&proc->asts_spin);
945 if (!list_empty(&proc->asts)) {
946 spin_unlock(&proc->asts_spin);
947 return POLLIN | POLLRDNORM;
948 }
949 spin_unlock(&proc->asts_spin);
950 return 0;
951 }
952
953 int dlm_user_daemon_available(void)
954 {
955 /* dlm_controld hasn't started (or, has started, but not
956 properly populated configfs) */
957
958 if (!dlm_our_nodeid())
959 return 0;
960
961 /* This is to deal with versions of dlm_controld that don't
962 know about the monitor device. We assume that if the
963 dlm_controld was started (above), but the monitor device
964 was never opened, that it's an old version. dlm_controld
965 should open the monitor device before populating configfs. */
966
967 if (dlm_monitor_unused)
968 return 1;
969
970 return atomic_read(&dlm_monitor_opened) ? 1 : 0;
971 }
972
973 static int ctl_device_open(struct inode *inode, struct file *file)
974 {
975 file->private_data = NULL;
976 return 0;
977 }
978
979 static int ctl_device_close(struct inode *inode, struct file *file)
980 {
981 return 0;
982 }
983
984 static int monitor_device_open(struct inode *inode, struct file *file)
985 {
986 atomic_inc(&dlm_monitor_opened);
987 dlm_monitor_unused = 0;
988 return 0;
989 }
990
991 static int monitor_device_close(struct inode *inode, struct file *file)
992 {
993 if (atomic_dec_and_test(&dlm_monitor_opened))
994 dlm_stop_lockspaces();
995 return 0;
996 }
997
998 static const struct file_operations device_fops = {
999 .open = device_open,
1000 .release = device_close,
1001 .read = device_read,
1002 .write = device_write,
1003 .poll = device_poll,
1004 .owner = THIS_MODULE,
1005 };
1006
1007 static const struct file_operations ctl_device_fops = {
1008 .open = ctl_device_open,
1009 .release = ctl_device_close,
1010 .read = device_read,
1011 .write = device_write,
1012 .owner = THIS_MODULE,
1013 };
1014
1015 static struct miscdevice ctl_device = {
1016 .name = "dlm-control",
1017 .fops = &ctl_device_fops,
1018 .minor = MISC_DYNAMIC_MINOR,
1019 };
1020
1021 static const struct file_operations monitor_device_fops = {
1022 .open = monitor_device_open,
1023 .release = monitor_device_close,
1024 .owner = THIS_MODULE,
1025 };
1026
1027 static struct miscdevice monitor_device = {
1028 .name = "dlm-monitor",
1029 .fops = &monitor_device_fops,
1030 .minor = MISC_DYNAMIC_MINOR,
1031 };
1032
1033 int __init dlm_user_init(void)
1034 {
1035 int error;
1036
1037 atomic_set(&dlm_monitor_opened, 0);
1038
1039 error = misc_register(&ctl_device);
1040 if (error) {
1041 log_print("misc_register failed for control device");
1042 goto out;
1043 }
1044
1045 error = misc_register(&monitor_device);
1046 if (error) {
1047 log_print("misc_register failed for monitor device");
1048 misc_deregister(&ctl_device);
1049 }
1050 out:
1051 return error;
1052 }
1053
1054 void dlm_user_exit(void)
1055 {
1056 misc_deregister(&ctl_device);
1057 misc_deregister(&monitor_device);
1058 }
Tomato firmware and modifications.