2 * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved.
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.
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>
15 #include <linux/poll.h>
16 #include <linux/signal.h>
17 #include <linux/spinlock.h>
18 #include <linux/smp_lock.h>
19 #include <linux/dlm.h>
20 #include <linux/dlm_device.h>
22 #include "dlm_internal.h"
23 #include "lockspace.h"
25 #include "lvb_table.h"
28 static const char name_prefix
[] = "dlm";
29 static const struct file_operations device_fops
;
33 struct dlm_lock_params32
{
47 char lvb
[DLM_USER_LVB_LEN
];
51 struct dlm_write_request32
{
58 struct dlm_lock_params32 lock
;
59 struct dlm_lspace_params lspace
;
60 struct dlm_purge_params purge
;
71 struct dlm_lock_result32
{
77 struct dlm_lksb32 lksb
;
80 /* Offsets may be zero if no data is present */
84 static void compat_input(struct dlm_write_request
*kb
,
85 struct dlm_write_request32
*kb32
,
88 kb
->version
[0] = kb32
->version
[0];
89 kb
->version
[1] = kb32
->version
[1];
90 kb
->version
[2] = kb32
->version
[2];
93 kb
->is64bit
= kb32
->is64bit
;
94 if (kb
->cmd
== DLM_USER_CREATE_LOCKSPACE
||
95 kb
->cmd
== DLM_USER_REMOVE_LOCKSPACE
) {
96 kb
->i
.lspace
.flags
= kb32
->i
.lspace
.flags
;
97 kb
->i
.lspace
.minor
= kb32
->i
.lspace
.minor
;
98 memcpy(kb
->i
.lspace
.name
, kb32
->i
.lspace
.name
, count
-
99 offsetof(struct dlm_write_request32
, i
.lspace
.name
));
100 } else if (kb
->cmd
== DLM_USER_PURGE
) {
101 kb
->i
.purge
.nodeid
= kb32
->i
.purge
.nodeid
;
102 kb
->i
.purge
.pid
= kb32
->i
.purge
.pid
;
104 kb
->i
.lock
.mode
= kb32
->i
.lock
.mode
;
105 kb
->i
.lock
.namelen
= kb32
->i
.lock
.namelen
;
106 kb
->i
.lock
.flags
= kb32
->i
.lock
.flags
;
107 kb
->i
.lock
.lkid
= kb32
->i
.lock
.lkid
;
108 kb
->i
.lock
.parent
= kb32
->i
.lock
.parent
;
109 kb
->i
.lock
.xid
= kb32
->i
.lock
.xid
;
110 kb
->i
.lock
.timeout
= kb32
->i
.lock
.timeout
;
111 kb
->i
.lock
.castparam
= (void *)(long)kb32
->i
.lock
.castparam
;
112 kb
->i
.lock
.castaddr
= (void *)(long)kb32
->i
.lock
.castaddr
;
113 kb
->i
.lock
.bastparam
= (void *)(long)kb32
->i
.lock
.bastparam
;
114 kb
->i
.lock
.bastaddr
= (void *)(long)kb32
->i
.lock
.bastaddr
;
115 kb
->i
.lock
.lksb
= (void *)(long)kb32
->i
.lock
.lksb
;
116 memcpy(kb
->i
.lock
.lvb
, kb32
->i
.lock
.lvb
, DLM_USER_LVB_LEN
);
117 memcpy(kb
->i
.lock
.name
, kb32
->i
.lock
.name
, count
-
118 offsetof(struct dlm_write_request32
, i
.lock
.name
));
122 static void compat_output(struct dlm_lock_result
*res
,
123 struct dlm_lock_result32
*res32
)
125 res32
->version
[0] = res
->version
[0];
126 res32
->version
[1] = res
->version
[1];
127 res32
->version
[2] = res
->version
[2];
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
;
134 res32
->lvb_offset
= res
->lvb_offset
;
135 res32
->length
= res
->length
;
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
;
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. */
155 static int lkb_is_endoflife(struct dlm_lkb
*lkb
, int sb_status
, int type
)
163 if (lkb
->lkb_grmode
== DLM_LOCK_IV
)
167 if (type
== AST_COMP
&& lkb
->lkb_grmode
== DLM_LOCK_IV
)
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 */
177 void dlm_user_add_ast(struct dlm_lkb
*lkb
, int type
)
180 struct dlm_user_args
*ua
;
181 struct dlm_user_proc
*proc
;
182 int eol
= 0, ast_type
;
184 if (lkb
->lkb_flags
& (DLM_IFL_ORPHAN
| DLM_IFL_DEAD
))
187 ls
= lkb
->lkb_resource
->res_ls
;
188 mutex_lock(&ls
->ls_clear_proc_locks
);
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. */
196 if (lkb
->lkb_flags
& (DLM_IFL_ORPHAN
| DLM_IFL_DEAD
))
199 DLM_ASSERT(lkb
->lkb_ua
, dlm_print_lkb(lkb
););
203 if (type
== AST_BAST
&& ua
->bastaddr
== NULL
)
206 spin_lock(&proc
->asts_spin
);
208 ast_type
= lkb
->lkb_ast_type
;
209 lkb
->lkb_ast_type
|= type
;
212 kref_get(&lkb
->lkb_ref
);
213 list_add_tail(&lkb
->lkb_astqueue
, &proc
->asts
);
214 wake_up_interruptible(&proc
->wait
);
216 if (type
== AST_COMP
&& (ast_type
& AST_COMP
))
217 log_debug(ls
, "ast overlap %x status %x %x",
218 lkb
->lkb_id
, ua
->lksb
.sb_status
, lkb
->lkb_flags
);
220 eol
= lkb_is_endoflife(lkb
, ua
->lksb
.sb_status
, type
);
222 lkb
->lkb_ast_type
&= ~AST_BAST
;
223 lkb
->lkb_flags
|= DLM_IFL_ENDOFLIFE
;
226 /* We want to copy the lvb to userspace when the completion
227 ast is read if the status is 0, the lock has an lvb and
228 lvb_ops says we should. We could probably have set_lvb_lock()
229 set update_user_lvb instead and not need old_mode */
231 if ((lkb
->lkb_ast_type
& AST_COMP
) &&
232 (lkb
->lkb_lksb
->sb_status
== 0) &&
233 lkb
->lkb_lksb
->sb_lvbptr
&&
234 dlm_lvb_operations
[ua
->old_mode
+ 1][lkb
->lkb_grmode
+ 1])
235 ua
->update_user_lvb
= 1;
237 ua
->update_user_lvb
= 0;
239 spin_unlock(&proc
->asts_spin
);
242 spin_lock(&proc
->locks_spin
);
243 if (!list_empty(&lkb
->lkb_ownqueue
)) {
244 list_del_init(&lkb
->lkb_ownqueue
);
247 spin_unlock(&proc
->locks_spin
);
250 mutex_unlock(&ls
->ls_clear_proc_locks
);
253 static int device_user_lock(struct dlm_user_proc
*proc
,
254 struct dlm_lock_params
*params
)
257 struct dlm_user_args
*ua
;
260 ls
= dlm_find_lockspace_local(proc
->lockspace
);
264 if (!params
->castaddr
|| !params
->lksb
) {
269 ua
= kzalloc(sizeof(struct dlm_user_args
), GFP_KERNEL
);
273 ua
->user_lksb
= params
->lksb
;
274 ua
->castparam
= params
->castparam
;
275 ua
->castaddr
= params
->castaddr
;
276 ua
->bastparam
= params
->bastparam
;
277 ua
->bastaddr
= params
->bastaddr
;
278 ua
->xid
= params
->xid
;
280 if (params
->flags
& DLM_LKF_CONVERT
)
281 error
= dlm_user_convert(ls
, ua
,
282 params
->mode
, params
->flags
,
283 params
->lkid
, params
->lvb
,
284 (unsigned long) params
->timeout
);
286 error
= dlm_user_request(ls
, ua
,
287 params
->mode
, params
->flags
,
288 params
->name
, params
->namelen
,
289 (unsigned long) params
->timeout
);
291 error
= ua
->lksb
.sb_lkid
;
294 dlm_put_lockspace(ls
);
298 static int device_user_unlock(struct dlm_user_proc
*proc
,
299 struct dlm_lock_params
*params
)
302 struct dlm_user_args
*ua
;
305 ls
= dlm_find_lockspace_local(proc
->lockspace
);
309 ua
= kzalloc(sizeof(struct dlm_user_args
), GFP_KERNEL
);
313 ua
->user_lksb
= params
->lksb
;
314 ua
->castparam
= params
->castparam
;
315 ua
->castaddr
= params
->castaddr
;
317 if (params
->flags
& DLM_LKF_CANCEL
)
318 error
= dlm_user_cancel(ls
, ua
, params
->flags
, params
->lkid
);
320 error
= dlm_user_unlock(ls
, ua
, params
->flags
, params
->lkid
,
323 dlm_put_lockspace(ls
);
327 static int device_user_deadlock(struct dlm_user_proc
*proc
,
328 struct dlm_lock_params
*params
)
333 ls
= dlm_find_lockspace_local(proc
->lockspace
);
337 error
= dlm_user_deadlock(ls
, params
->flags
, params
->lkid
);
339 dlm_put_lockspace(ls
);
343 static int create_misc_device(struct dlm_ls
*ls
, char *name
)
348 len
= strlen(name
) + strlen(name_prefix
) + 2;
349 ls
->ls_device
.name
= kzalloc(len
, GFP_KERNEL
);
350 if (!ls
->ls_device
.name
)
353 snprintf((char *)ls
->ls_device
.name
, len
, "%s_%s", name_prefix
,
355 ls
->ls_device
.fops
= &device_fops
;
356 ls
->ls_device
.minor
= MISC_DYNAMIC_MINOR
;
358 error
= misc_register(&ls
->ls_device
);
360 kfree(ls
->ls_device
.name
);
366 static int device_user_purge(struct dlm_user_proc
*proc
,
367 struct dlm_purge_params
*params
)
372 ls
= dlm_find_lockspace_local(proc
->lockspace
);
376 error
= dlm_user_purge(ls
, proc
, params
->nodeid
, params
->pid
);
378 dlm_put_lockspace(ls
);
382 static int device_create_lockspace(struct dlm_lspace_params
*params
)
384 dlm_lockspace_t
*lockspace
;
388 if (!capable(CAP_SYS_ADMIN
))
391 error
= dlm_new_lockspace(params
->name
, strlen(params
->name
),
392 &lockspace
, params
->flags
, DLM_USER_LVB_LEN
);
396 ls
= dlm_find_lockspace_local(lockspace
);
400 error
= create_misc_device(ls
, params
->name
);
401 dlm_put_lockspace(ls
);
404 dlm_release_lockspace(lockspace
, 0);
406 error
= ls
->ls_device
.minor
;
411 static int device_remove_lockspace(struct dlm_lspace_params
*params
)
413 dlm_lockspace_t
*lockspace
;
415 int error
, force
= 0;
417 if (!capable(CAP_SYS_ADMIN
))
420 ls
= dlm_find_lockspace_device(params
->minor
);
424 /* Deregister the misc device first, so we don't have
425 * a device that's not attached to a lockspace. If
426 * dlm_release_lockspace fails then we can recreate it
428 error
= misc_deregister(&ls
->ls_device
);
430 dlm_put_lockspace(ls
);
433 kfree(ls
->ls_device
.name
);
435 if (params
->flags
& DLM_USER_LSFLG_FORCEFREE
)
438 lockspace
= ls
->ls_local_handle
;
440 /* dlm_release_lockspace waits for references to go to zero,
441 so all processes will need to close their device for the ls
442 before the release will procede */
444 dlm_put_lockspace(ls
);
445 error
= dlm_release_lockspace(lockspace
, force
);
447 create_misc_device(ls
, ls
->ls_name
);
452 /* Check the user's version matches ours */
453 static int check_version(struct dlm_write_request
*req
)
455 if (req
->version
[0] != DLM_DEVICE_VERSION_MAJOR
||
456 (req
->version
[0] == DLM_DEVICE_VERSION_MAJOR
&&
457 req
->version
[1] > DLM_DEVICE_VERSION_MINOR
)) {
459 printk(KERN_DEBUG
"dlm: process %s (%d) version mismatch "
460 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
462 task_pid_nr(current
),
466 DLM_DEVICE_VERSION_MAJOR
,
467 DLM_DEVICE_VERSION_MINOR
,
468 DLM_DEVICE_VERSION_PATCH
);
478 * dlm_user_request -> request_lock
479 * dlm_user_convert -> convert_lock
482 * dlm_user_unlock -> unlock_lock
483 * dlm_user_cancel -> cancel_lock
485 * device_create_lockspace
488 * device_remove_lockspace
489 * dlm_release_lockspace
492 /* a write to a lockspace device is a lock or unlock request, a write
493 to the control device is to create/remove a lockspace */
495 static ssize_t
device_write(struct file
*file
, const char __user
*buf
,
496 size_t count
, loff_t
*ppos
)
498 struct dlm_user_proc
*proc
= file
->private_data
;
499 struct dlm_write_request
*kbuf
;
500 sigset_t tmpsig
, allsigs
;
504 if (count
< sizeof(struct dlm_write_request32
))
506 if (count
< sizeof(struct dlm_write_request
))
510 kbuf
= kzalloc(count
+ 1, GFP_KERNEL
);
514 if (copy_from_user(kbuf
, buf
, count
)) {
519 if (check_version(kbuf
)) {
525 if (!kbuf
->is64bit
) {
526 struct dlm_write_request32
*k32buf
;
527 k32buf
= (struct dlm_write_request32
*)kbuf
;
528 kbuf
= kmalloc(count
+ 1 + (sizeof(struct dlm_write_request
) -
529 sizeof(struct dlm_write_request32
)), GFP_KERNEL
);
534 set_bit(DLM_PROC_FLAGS_COMPAT
, &proc
->flags
);
535 compat_input(kbuf
, k32buf
, count
+ 1);
540 /* do we really need this? can a write happen after a close? */
541 if ((kbuf
->cmd
== DLM_USER_LOCK
|| kbuf
->cmd
== DLM_USER_UNLOCK
) &&
542 (proc
&& test_bit(DLM_PROC_FLAGS_CLOSING
, &proc
->flags
)))
545 sigfillset(&allsigs
);
546 sigprocmask(SIG_BLOCK
, &allsigs
, &tmpsig
);
554 log_print("no locking on control device");
557 error
= device_user_lock(proc
, &kbuf
->i
.lock
);
560 case DLM_USER_UNLOCK
:
562 log_print("no locking on control device");
565 error
= device_user_unlock(proc
, &kbuf
->i
.lock
);
568 case DLM_USER_DEADLOCK
:
570 log_print("no locking on control device");
573 error
= device_user_deadlock(proc
, &kbuf
->i
.lock
);
576 case DLM_USER_CREATE_LOCKSPACE
:
578 log_print("create/remove only on control device");
581 error
= device_create_lockspace(&kbuf
->i
.lspace
);
584 case DLM_USER_REMOVE_LOCKSPACE
:
586 log_print("create/remove only on control device");
589 error
= device_remove_lockspace(&kbuf
->i
.lspace
);
594 log_print("no locking on control device");
597 error
= device_user_purge(proc
, &kbuf
->i
.purge
);
601 log_print("Unknown command passed to DLM device : %d\n",
606 sigprocmask(SIG_SETMASK
, &tmpsig
, NULL
);
613 /* Every process that opens the lockspace device has its own "proc" structure
614 hanging off the open file that's used to keep track of locks owned by the
615 process and asts that need to be delivered to the process. */
617 static int device_open(struct inode
*inode
, struct file
*file
)
619 struct dlm_user_proc
*proc
;
623 ls
= dlm_find_lockspace_device(iminor(inode
));
629 proc
= kzalloc(sizeof(struct dlm_user_proc
), GFP_KERNEL
);
631 dlm_put_lockspace(ls
);
636 proc
->lockspace
= ls
->ls_local_handle
;
637 INIT_LIST_HEAD(&proc
->asts
);
638 INIT_LIST_HEAD(&proc
->locks
);
639 INIT_LIST_HEAD(&proc
->unlocking
);
640 spin_lock_init(&proc
->asts_spin
);
641 spin_lock_init(&proc
->locks_spin
);
642 init_waitqueue_head(&proc
->wait
);
643 file
->private_data
= proc
;
649 static int device_close(struct inode
*inode
, struct file
*file
)
651 struct dlm_user_proc
*proc
= file
->private_data
;
653 sigset_t tmpsig
, allsigs
;
655 ls
= dlm_find_lockspace_local(proc
->lockspace
);
659 sigfillset(&allsigs
);
660 sigprocmask(SIG_BLOCK
, &allsigs
, &tmpsig
);
662 set_bit(DLM_PROC_FLAGS_CLOSING
, &proc
->flags
);
664 dlm_clear_proc_locks(ls
, proc
);
666 /* at this point no more lkb's should exist for this lockspace,
667 so there's no chance of dlm_user_add_ast() being called and
668 looking for lkb->ua->proc */
671 file
->private_data
= NULL
;
673 dlm_put_lockspace(ls
);
674 dlm_put_lockspace(ls
); /* for the find in device_open() */
676 /* FIXME: AUTOFREE: if this ls is no longer used do
677 device_remove_lockspace() */
679 sigprocmask(SIG_SETMASK
, &tmpsig
, NULL
);
685 static int copy_result_to_user(struct dlm_user_args
*ua
, int compat
, int type
,
686 int bmode
, char __user
*buf
, size_t count
)
689 struct dlm_lock_result32 result32
;
691 struct dlm_lock_result result
;
697 memset(&result
, 0, sizeof(struct dlm_lock_result
));
698 result
.version
[0] = DLM_DEVICE_VERSION_MAJOR
;
699 result
.version
[1] = DLM_DEVICE_VERSION_MINOR
;
700 result
.version
[2] = DLM_DEVICE_VERSION_PATCH
;
701 memcpy(&result
.lksb
, &ua
->lksb
, sizeof(struct dlm_lksb
));
702 result
.user_lksb
= ua
->user_lksb
;
704 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
705 in a conversion unless the conversion is successful. See code
706 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though,
707 notes that a new blocking AST address and parameter are set even if
708 the conversion fails, so maybe we should just do that. */
710 if (type
== AST_BAST
) {
711 result
.user_astaddr
= ua
->bastaddr
;
712 result
.user_astparam
= ua
->bastparam
;
713 result
.bast_mode
= bmode
;
715 result
.user_astaddr
= ua
->castaddr
;
716 result
.user_astparam
= ua
->castparam
;
721 len
= sizeof(struct dlm_lock_result32
);
724 len
= sizeof(struct dlm_lock_result
);
727 /* copy lvb to userspace if there is one, it's been updated, and
728 the user buffer has space for it */
730 if (ua
->update_user_lvb
&& ua
->lksb
.sb_lvbptr
&&
731 count
>= len
+ DLM_USER_LVB_LEN
) {
732 if (copy_to_user(buf
+len
, ua
->lksb
.sb_lvbptr
,
738 result
.lvb_offset
= len
;
739 len
+= DLM_USER_LVB_LEN
;
746 compat_output(&result
, &result32
);
747 resultptr
= &result32
;
751 if (copy_to_user(buf
, resultptr
, struct_len
))
759 static int copy_version_to_user(char __user
*buf
, size_t count
)
761 struct dlm_device_version ver
;
763 memset(&ver
, 0, sizeof(struct dlm_device_version
));
764 ver
.version
[0] = DLM_DEVICE_VERSION_MAJOR
;
765 ver
.version
[1] = DLM_DEVICE_VERSION_MINOR
;
766 ver
.version
[2] = DLM_DEVICE_VERSION_PATCH
;
768 if (copy_to_user(buf
, &ver
, sizeof(struct dlm_device_version
)))
770 return sizeof(struct dlm_device_version
);
773 /* a read returns a single ast described in a struct dlm_lock_result */
775 static ssize_t
device_read(struct file
*file
, char __user
*buf
, size_t count
,
778 struct dlm_user_proc
*proc
= file
->private_data
;
780 DECLARE_WAITQUEUE(wait
, current
);
781 int error
, type
=0, bmode
=0, removed
= 0;
783 if (count
== sizeof(struct dlm_device_version
)) {
784 error
= copy_version_to_user(buf
, count
);
789 log_print("non-version read from control device %zu", count
);
794 if (count
< sizeof(struct dlm_lock_result32
))
796 if (count
< sizeof(struct dlm_lock_result
))
800 /* do we really need this? can a read happen after a close? */
801 if (test_bit(DLM_PROC_FLAGS_CLOSING
, &proc
->flags
))
804 spin_lock(&proc
->asts_spin
);
805 if (list_empty(&proc
->asts
)) {
806 if (file
->f_flags
& O_NONBLOCK
) {
807 spin_unlock(&proc
->asts_spin
);
811 add_wait_queue(&proc
->wait
, &wait
);
814 set_current_state(TASK_INTERRUPTIBLE
);
815 if (list_empty(&proc
->asts
) && !signal_pending(current
)) {
816 spin_unlock(&proc
->asts_spin
);
818 spin_lock(&proc
->asts_spin
);
821 set_current_state(TASK_RUNNING
);
822 remove_wait_queue(&proc
->wait
, &wait
);
824 if (signal_pending(current
)) {
825 spin_unlock(&proc
->asts_spin
);
830 /* there may be both completion and blocking asts to return for
831 the lkb, don't remove lkb from asts list unless no asts remain */
833 lkb
= list_entry(proc
->asts
.next
, struct dlm_lkb
, lkb_astqueue
);
835 if (lkb
->lkb_ast_type
& AST_COMP
) {
836 lkb
->lkb_ast_type
&= ~AST_COMP
;
838 } else if (lkb
->lkb_ast_type
& AST_BAST
) {
839 lkb
->lkb_ast_type
&= ~AST_BAST
;
841 bmode
= lkb
->lkb_bastmode
;
844 if (!lkb
->lkb_ast_type
) {
845 list_del(&lkb
->lkb_astqueue
);
848 spin_unlock(&proc
->asts_spin
);
850 error
= copy_result_to_user(lkb
->lkb_ua
,
851 test_bit(DLM_PROC_FLAGS_COMPAT
, &proc
->flags
),
852 type
, bmode
, buf
, count
);
854 /* removes reference for the proc->asts lists added by
855 dlm_user_add_ast() and may result in the lkb being freed */
862 static unsigned int device_poll(struct file
*file
, poll_table
*wait
)
864 struct dlm_user_proc
*proc
= file
->private_data
;
866 poll_wait(file
, &proc
->wait
, wait
);
868 spin_lock(&proc
->asts_spin
);
869 if (!list_empty(&proc
->asts
)) {
870 spin_unlock(&proc
->asts_spin
);
871 return POLLIN
| POLLRDNORM
;
873 spin_unlock(&proc
->asts_spin
);
877 static int ctl_device_open(struct inode
*inode
, struct file
*file
)
880 file
->private_data
= NULL
;
884 static int ctl_device_close(struct inode
*inode
, struct file
*file
)
889 static const struct file_operations device_fops
= {
891 .release
= device_close
,
893 .write
= device_write
,
895 .owner
= THIS_MODULE
,
898 static const struct file_operations ctl_device_fops
= {
899 .open
= ctl_device_open
,
900 .release
= ctl_device_close
,
902 .write
= device_write
,
903 .owner
= THIS_MODULE
,
906 static struct miscdevice ctl_device
= {
907 .name
= "dlm-control",
908 .fops
= &ctl_device_fops
,
909 .minor
= MISC_DYNAMIC_MINOR
,
912 int __init
dlm_user_init(void)
916 error
= misc_register(&ctl_device
);
918 log_print("misc_register failed for control device");
923 void dlm_user_exit(void)
925 misc_deregister(&ctl_device
);