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-rw-r--r--fs/dlm/device.c1084
1 files changed, 1084 insertions, 0 deletions
diff --git a/fs/dlm/device.c b/fs/dlm/device.c
new file mode 100644
index 000000000000..a8bf600ed13d
--- /dev/null
+++ b/fs/dlm/device.c
@@ -0,0 +1,1084 @@
1/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
5** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
6**
7** This copyrighted material is made available to anyone wishing to use,
8** modify, copy, or redistribute it subject to the terms and conditions
9** of the GNU General Public License v.2.
10**
11*******************************************************************************
12******************************************************************************/
13
14/*
15 * device.c
16 *
17 * This is the userland interface to the DLM.
18 *
19 * The locking is done via a misc char device (find the
20 * registered minor number in /proc/misc).
21 *
22 * User code should not use this interface directly but
23 * call the library routines in libdlm.a instead.
24 *
25 */
26
27#include <linux/miscdevice.h>
28#include <linux/init.h>
29#include <linux/wait.h>
30#include <linux/module.h>
31#include <linux/file.h>
32#include <linux/fs.h>
33#include <linux/poll.h>
34#include <linux/signal.h>
35#include <linux/spinlock.h>
36#include <linux/idr.h>
37
38#include <linux/dlm.h>
39#include <linux/dlm_device.h>
40
41#include "lvb_table.h"
42
43static struct file_operations _dlm_fops;
44static const char *name_prefix="dlm";
45static struct list_head user_ls_list;
46static struct semaphore user_ls_lock;
47
48/* Lock infos are stored in here indexed by lock ID */
49static DEFINE_IDR(lockinfo_idr);
50static rwlock_t lockinfo_lock;
51
52/* Flags in li_flags */
53#define LI_FLAG_COMPLETE 1
54#define LI_FLAG_FIRSTLOCK 2
55#define LI_FLAG_PERSISTENT 3
56
57/* flags in ls_flags*/
58#define LS_FLAG_DELETED 1
59#define LS_FLAG_AUTOFREE 2
60
61
62#define LOCKINFO_MAGIC 0x53595324
63
64struct lock_info {
65 uint32_t li_magic;
66 uint8_t li_cmd;
67 int8_t li_grmode;
68 int8_t li_rqmode;
69 struct dlm_lksb li_lksb;
70 wait_queue_head_t li_waitq;
71 unsigned long li_flags;
72 void __user *li_castparam;
73 void __user *li_castaddr;
74 void __user *li_bastparam;
75 void __user *li_bastaddr;
76 void __user *li_pend_bastparam;
77 void __user *li_pend_bastaddr;
78 struct list_head li_ownerqueue;
79 struct file_info *li_file;
80 struct dlm_lksb __user *li_user_lksb;
81 struct semaphore li_firstlock;
82};
83
84/* A queued AST no less */
85struct ast_info {
86 struct dlm_lock_result result;
87 struct list_head list;
88 uint32_t lvb_updated;
89 uint32_t progress; /* How much has been read */
90};
91
92/* One of these per userland lockspace */
93struct user_ls {
94 void *ls_lockspace;
95 atomic_t ls_refcnt;
96 long ls_flags;
97
98 /* Passed into misc_register() */
99 struct miscdevice ls_miscinfo;
100 struct list_head ls_list;
101};
102
103/* misc_device info for the control device */
104static struct miscdevice ctl_device;
105
106/*
107 * Stuff we hang off the file struct.
108 * The first two are to cope with unlocking all the
109 * locks help by a process when it dies.
110 */
111struct file_info {
112 struct list_head fi_li_list; /* List of active lock_infos */
113 spinlock_t fi_li_lock;
114 struct list_head fi_ast_list; /* Queue of ASTs to be delivered */
115 spinlock_t fi_ast_lock;
116 wait_queue_head_t fi_wait;
117 struct user_ls *fi_ls;
118 atomic_t fi_refcnt; /* Number of users */
119 unsigned long fi_flags; /* Bit 1 means the device is open */
120};
121
122
123/* get and put ops for file_info.
124 Actually I don't really like "get" and "put", but everyone
125 else seems to use them and I can't think of anything
126 nicer at the moment */
127static void get_file_info(struct file_info *f)
128{
129 atomic_inc(&f->fi_refcnt);
130}
131
132static void put_file_info(struct file_info *f)
133{
134 if (atomic_dec_and_test(&f->fi_refcnt))
135 kfree(f);
136}
137
138static void release_lockinfo(struct lock_info *li)
139{
140 put_file_info(li->li_file);
141
142 write_lock(&lockinfo_lock);
143 idr_remove(&lockinfo_idr, li->li_lksb.sb_lkid);
144 write_unlock(&lockinfo_lock);
145
146 if (li->li_lksb.sb_lvbptr)
147 kfree(li->li_lksb.sb_lvbptr);
148 kfree(li);
149
150 module_put(THIS_MODULE);
151}
152
153static struct lock_info *get_lockinfo(uint32_t lockid)
154{
155 struct lock_info *li;
156
157 read_lock(&lockinfo_lock);
158 li = idr_find(&lockinfo_idr, lockid);
159 read_unlock(&lockinfo_lock);
160
161 return li;
162}
163
164static int add_lockinfo(struct lock_info *li)
165{
166 int n;
167 int r;
168 int ret = -EINVAL;
169
170 write_lock(&lockinfo_lock);
171
172 if (idr_find(&lockinfo_idr, li->li_lksb.sb_lkid))
173 goto out_up;
174
175 ret = -ENOMEM;
176 r = idr_pre_get(&lockinfo_idr, GFP_KERNEL);
177 if (!r)
178 goto out_up;
179
180 r = idr_get_new_above(&lockinfo_idr, li, li->li_lksb.sb_lkid, &n);
181 if (r)
182 goto out_up;
183
184 if (n != li->li_lksb.sb_lkid) {
185 idr_remove(&lockinfo_idr, n);
186 goto out_up;
187 }
188
189 ret = 0;
190
191 out_up:
192 write_unlock(&lockinfo_lock);
193
194 return ret;
195}
196
197
198static struct user_ls *__find_lockspace(int minor)
199{
200 struct user_ls *lsinfo;
201
202 list_for_each_entry(lsinfo, &user_ls_list, ls_list) {
203 if (lsinfo->ls_miscinfo.minor == minor)
204 return lsinfo;
205 }
206 return NULL;
207}
208
209/* Find a lockspace struct given the device minor number */
210static struct user_ls *find_lockspace(int minor)
211{
212 struct user_ls *lsinfo;
213
214 down(&user_ls_lock);
215 lsinfo = __find_lockspace(minor);
216 up(&user_ls_lock);
217
218 return lsinfo;
219}
220
221static void add_lockspace_to_list(struct user_ls *lsinfo)
222{
223 down(&user_ls_lock);
224 list_add(&lsinfo->ls_list, &user_ls_list);
225 up(&user_ls_lock);
226}
227
228/* Register a lockspace with the DLM and create a misc
229 device for userland to access it */
230static int register_lockspace(char *name, struct user_ls **ls, int flags)
231{
232 struct user_ls *newls;
233 int status;
234 int namelen;
235
236 namelen = strlen(name)+strlen(name_prefix)+2;
237
238 newls = kmalloc(sizeof(struct user_ls), GFP_KERNEL);
239 if (!newls)
240 return -ENOMEM;
241 memset(newls, 0, sizeof(struct user_ls));
242
243 newls->ls_miscinfo.name = kmalloc(namelen, GFP_KERNEL);
244 if (!newls->ls_miscinfo.name) {
245 kfree(newls);
246 return -ENOMEM;
247 }
248
249 status = dlm_new_lockspace(name, strlen(name), &newls->ls_lockspace, 0,
250 DLM_USER_LVB_LEN);
251 if (status != 0) {
252 kfree(newls->ls_miscinfo.name);
253 kfree(newls);
254 return status;
255 }
256
257 snprintf((char*)newls->ls_miscinfo.name, namelen, "%s_%s",
258 name_prefix, name);
259
260 newls->ls_miscinfo.fops = &_dlm_fops;
261 newls->ls_miscinfo.minor = MISC_DYNAMIC_MINOR;
262
263 status = misc_register(&newls->ls_miscinfo);
264 if (status) {
265 printk(KERN_ERR "dlm: misc register failed for %s\n", name);
266 dlm_release_lockspace(newls->ls_lockspace, 0);
267 kfree(newls->ls_miscinfo.name);
268 kfree(newls);
269 return status;
270 }
271
272 if (flags & DLM_USER_LSFLG_AUTOFREE)
273 set_bit(LS_FLAG_AUTOFREE, &newls->ls_flags);
274
275 add_lockspace_to_list(newls);
276 *ls = newls;
277 return 0;
278}
279
280/* Called with the user_ls_lock semaphore held */
281static int unregister_lockspace(struct user_ls *lsinfo, int force)
282{
283 int status;
284
285 status = dlm_release_lockspace(lsinfo->ls_lockspace, force);
286 if (status)
287 return status;
288
289 status = misc_deregister(&lsinfo->ls_miscinfo);
290 if (status)
291 return status;
292
293 list_del(&lsinfo->ls_list);
294 set_bit(LS_FLAG_DELETED, &lsinfo->ls_flags);
295 lsinfo->ls_lockspace = NULL;
296 if (atomic_read(&lsinfo->ls_refcnt) == 0) {
297 kfree(lsinfo->ls_miscinfo.name);
298 kfree(lsinfo);
299 }
300
301 return 0;
302}
303
304/* Add it to userland's AST queue */
305static void add_to_astqueue(struct lock_info *li, void *astaddr, void *astparam,
306 int lvb_updated)
307{
308 struct ast_info *ast = kmalloc(sizeof(struct ast_info), GFP_KERNEL);
309 if (!ast)
310 return;
311
312 memset(ast, 0, sizeof(*ast));
313 ast->result.user_astparam = astparam;
314 ast->result.user_astaddr = astaddr;
315 ast->result.user_lksb = li->li_user_lksb;
316 memcpy(&ast->result.lksb, &li->li_lksb, sizeof(struct dlm_lksb));
317 ast->lvb_updated = lvb_updated;
318
319 spin_lock(&li->li_file->fi_ast_lock);
320 list_add_tail(&ast->list, &li->li_file->fi_ast_list);
321 spin_unlock(&li->li_file->fi_ast_lock);
322 wake_up_interruptible(&li->li_file->fi_wait);
323}
324
325static void bast_routine(void *param, int mode)
326{
327 struct lock_info *li = param;
328
329 if (li && li->li_bastaddr)
330 add_to_astqueue(li, li->li_bastaddr, li->li_bastparam, 0);
331}
332
333/*
334 * This is the kernel's AST routine.
335 * All lock, unlock & query operations complete here.
336 * The only syncronous ops are those done during device close.
337 */
338static void ast_routine(void *param)
339{
340 struct lock_info *li = param;
341
342 /* Param may be NULL if a persistent lock is unlocked by someone else */
343 if (!li)
344 return;
345
346 /* If this is a succesful conversion then activate the blocking ast
347 * args from the conversion request */
348 if (!test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags) &&
349 li->li_lksb.sb_status == 0) {
350
351 li->li_bastparam = li->li_pend_bastparam;
352 li->li_bastaddr = li->li_pend_bastaddr;
353 li->li_pend_bastaddr = NULL;
354 }
355
356 /* If it's an async request then post data to the user's AST queue. */
357 if (li->li_castaddr) {
358 int lvb_updated = 0;
359
360 /* See if the lvb has been updated */
361 if (dlm_lvb_operations[li->li_grmode+1][li->li_rqmode+1] == 1)
362 lvb_updated = 1;
363
364 if (li->li_lksb.sb_status == 0)
365 li->li_grmode = li->li_rqmode;
366
367 /* Only queue AST if the device is still open */
368 if (test_bit(1, &li->li_file->fi_flags))
369 add_to_astqueue(li, li->li_castaddr, li->li_castparam,
370 lvb_updated);
371
372 /* If it's a new lock operation that failed, then
373 * remove it from the owner queue and free the
374 * lock_info.
375 */
376 if (test_and_clear_bit(LI_FLAG_FIRSTLOCK, &li->li_flags) &&
377 li->li_lksb.sb_status != 0) {
378
379 /* Wait till dlm_lock() has finished */
380 down(&li->li_firstlock);
381 up(&li->li_firstlock);
382
383 spin_lock(&li->li_file->fi_li_lock);
384 list_del(&li->li_ownerqueue);
385 spin_unlock(&li->li_file->fi_li_lock);
386 release_lockinfo(li);
387 return;
388 }
389 /* Free unlocks & queries */
390 if (li->li_lksb.sb_status == -DLM_EUNLOCK ||
391 li->li_cmd == DLM_USER_QUERY) {
392 release_lockinfo(li);
393 }
394 } else {
395 /* Synchronous request, just wake up the caller */
396 set_bit(LI_FLAG_COMPLETE, &li->li_flags);
397 wake_up_interruptible(&li->li_waitq);
398 }
399}
400
401/*
402 * Wait for the lock op to complete and return the status.
403 */
404static int wait_for_ast(struct lock_info *li)
405{
406 /* Wait for the AST routine to complete */
407 set_task_state(current, TASK_INTERRUPTIBLE);
408 while (!test_bit(LI_FLAG_COMPLETE, &li->li_flags))
409 schedule();
410
411 set_task_state(current, TASK_RUNNING);
412
413 return li->li_lksb.sb_status;
414}
415
416
417/* Open on control device */
418static int dlm_ctl_open(struct inode *inode, struct file *file)
419{
420 file->private_data = NULL;
421 return 0;
422}
423
424/* Close on control device */
425static int dlm_ctl_close(struct inode *inode, struct file *file)
426{
427 return 0;
428}
429
430/* Open on lockspace device */
431static int dlm_open(struct inode *inode, struct file *file)
432{
433 struct file_info *f;
434 struct user_ls *lsinfo;
435
436 lsinfo = find_lockspace(iminor(inode));
437 if (!lsinfo)
438 return -ENOENT;
439
440 f = kmalloc(sizeof(struct file_info), GFP_KERNEL);
441 if (!f)
442 return -ENOMEM;
443
444 atomic_inc(&lsinfo->ls_refcnt);
445 INIT_LIST_HEAD(&f->fi_li_list);
446 INIT_LIST_HEAD(&f->fi_ast_list);
447 spin_lock_init(&f->fi_li_lock);
448 spin_lock_init(&f->fi_ast_lock);
449 init_waitqueue_head(&f->fi_wait);
450 f->fi_ls = lsinfo;
451 f->fi_flags = 0;
452 get_file_info(f);
453 set_bit(1, &f->fi_flags);
454
455 file->private_data = f;
456
457 return 0;
458}
459
460/* Check the user's version matches ours */
461static int check_version(struct dlm_write_request *req)
462{
463 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
464 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
465 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
466
467 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
468 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
469 current->comm,
470 current->pid,
471 req->version[0],
472 req->version[1],
473 req->version[2],
474 DLM_DEVICE_VERSION_MAJOR,
475 DLM_DEVICE_VERSION_MINOR,
476 DLM_DEVICE_VERSION_PATCH);
477 return -EINVAL;
478 }
479 return 0;
480}
481
482/* Close on lockspace device */
483static int dlm_close(struct inode *inode, struct file *file)
484{
485 struct file_info *f = file->private_data;
486 struct lock_info li;
487 struct lock_info *old_li, *safe;
488 sigset_t tmpsig;
489 sigset_t allsigs;
490 struct user_ls *lsinfo;
491 DECLARE_WAITQUEUE(wq, current);
492
493 lsinfo = find_lockspace(iminor(inode));
494 if (!lsinfo)
495 return -ENOENT;
496
497 /* Mark this closed so that ASTs will not be delivered any more */
498 clear_bit(1, &f->fi_flags);
499
500 /* Block signals while we are doing this */
501 sigfillset(&allsigs);
502 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
503
504 /* We use our own lock_info struct here, so that any
505 * outstanding "real" ASTs will be delivered with the
506 * corresponding "real" params, thus freeing the lock_info
507 * that belongs the lock. This catches the corner case where
508 * a lock is BUSY when we try to unlock it here
509 */
510 memset(&li, 0, sizeof(li));
511 clear_bit(LI_FLAG_COMPLETE, &li.li_flags);
512 init_waitqueue_head(&li.li_waitq);
513 add_wait_queue(&li.li_waitq, &wq);
514
515 /*
516 * Free any outstanding locks, they are on the
517 * list in LIFO order so there should be no problems
518 * about unlocking parents before children.
519 */
520 list_for_each_entry_safe(old_li, safe, &f->fi_li_list, li_ownerqueue) {
521 int status;
522 int flags = 0;
523
524 /* Don't unlock persistent locks, just mark them orphaned */
525 if (test_bit(LI_FLAG_PERSISTENT, &old_li->li_flags)) {
526 list_del(&old_li->li_ownerqueue);
527
528 /* Update master copy */
529 /* TODO: Check locking core updates the local and
530 remote ORPHAN flags */
531 li.li_lksb.sb_lkid = old_li->li_lksb.sb_lkid;
532 status = dlm_lock(f->fi_ls->ls_lockspace,
533 old_li->li_grmode, &li.li_lksb,
534 DLM_LKF_CONVERT|DLM_LKF_ORPHAN,
535 NULL, 0, 0, ast_routine, NULL,
536 NULL, NULL);
537 if (status != 0)
538 printk("dlm: Error orphaning lock %x: %d\n",
539 old_li->li_lksb.sb_lkid, status);
540
541 /* But tidy our references in it */
542 release_lockinfo(old_li);
543 continue;
544 }
545
546 clear_bit(LI_FLAG_COMPLETE, &li.li_flags);
547
548 flags = DLM_LKF_FORCEUNLOCK;
549 if (old_li->li_grmode >= DLM_LOCK_PW)
550 flags |= DLM_LKF_IVVALBLK;
551
552 status = dlm_unlock(f->fi_ls->ls_lockspace,
553 old_li->li_lksb.sb_lkid, flags,
554 &li.li_lksb, &li);
555
556 /* Must wait for it to complete as the next lock could be its
557 * parent */
558 if (status == 0)
559 wait_for_ast(&li);
560
561 /* Unlock suceeded, free the lock_info struct. */
562 if (status == 0)
563 release_lockinfo(old_li);
564 }
565
566 remove_wait_queue(&li.li_waitq, &wq);
567
568 /*
569 * If this is the last reference to the lockspace
570 * then free the struct. If it's an AUTOFREE lockspace
571 * then free the whole thing.
572 */
573 down(&user_ls_lock);
574 if (atomic_dec_and_test(&lsinfo->ls_refcnt)) {
575
576 if (lsinfo->ls_lockspace) {
577 if (test_bit(LS_FLAG_AUTOFREE, &lsinfo->ls_flags)) {
578 unregister_lockspace(lsinfo, 1);
579 }
580 } else {
581 kfree(lsinfo->ls_miscinfo.name);
582 kfree(lsinfo);
583 }
584 }
585 up(&user_ls_lock);
586 put_file_info(f);
587
588 /* Restore signals */
589 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
590 recalc_sigpending();
591
592 return 0;
593}
594
595static int do_user_create_lockspace(struct file_info *fi, uint8_t cmd,
596 struct dlm_lspace_params *kparams)
597{
598 int status;
599 struct user_ls *lsinfo;
600
601 if (!capable(CAP_SYS_ADMIN))
602 return -EPERM;
603
604 status = register_lockspace(kparams->name, &lsinfo, kparams->flags);
605
606 /* If it succeeded then return the minor number */
607 if (status == 0)
608 status = lsinfo->ls_miscinfo.minor;
609
610 return status;
611}
612
613static int do_user_remove_lockspace(struct file_info *fi, uint8_t cmd,
614 struct dlm_lspace_params *kparams)
615{
616 int status;
617 int force = 1;
618 struct user_ls *lsinfo;
619
620 if (!capable(CAP_SYS_ADMIN))
621 return -EPERM;
622
623 down(&user_ls_lock);
624 lsinfo = __find_lockspace(kparams->minor);
625 if (!lsinfo) {
626 up(&user_ls_lock);
627 return -EINVAL;
628 }
629
630 if (kparams->flags & DLM_USER_LSFLG_FORCEFREE)
631 force = 2;
632
633 status = unregister_lockspace(lsinfo, force);
634 up(&user_ls_lock);
635
636 return status;
637}
638
639/* Read call, might block if no ASTs are waiting.
640 * It will only ever return one message at a time, regardless
641 * of how many are pending.
642 */
643static ssize_t dlm_read(struct file *file, char __user *buffer, size_t count,
644 loff_t *ppos)
645{
646 struct file_info *fi = file->private_data;
647 struct ast_info *ast;
648 int data_size;
649 int offset;
650 DECLARE_WAITQUEUE(wait, current);
651
652 if (count < sizeof(struct dlm_lock_result))
653 return -EINVAL;
654
655 spin_lock(&fi->fi_ast_lock);
656 if (list_empty(&fi->fi_ast_list)) {
657
658 /* No waiting ASTs.
659 * Return EOF if the lockspace been deleted.
660 */
661 if (test_bit(LS_FLAG_DELETED, &fi->fi_ls->ls_flags))
662 return 0;
663
664 if (file->f_flags & O_NONBLOCK) {
665 spin_unlock(&fi->fi_ast_lock);
666 return -EAGAIN;
667 }
668
669 add_wait_queue(&fi->fi_wait, &wait);
670
671 repeat:
672 set_current_state(TASK_INTERRUPTIBLE);
673 if (list_empty(&fi->fi_ast_list) &&
674 !signal_pending(current)) {
675
676 spin_unlock(&fi->fi_ast_lock);
677 schedule();
678 spin_lock(&fi->fi_ast_lock);
679 goto repeat;
680 }
681
682 current->state = TASK_RUNNING;
683 remove_wait_queue(&fi->fi_wait, &wait);
684
685 if (signal_pending(current)) {
686 spin_unlock(&fi->fi_ast_lock);
687 return -ERESTARTSYS;
688 }
689 }
690
691 ast = list_entry(fi->fi_ast_list.next, struct ast_info, list);
692 list_del(&ast->list);
693 spin_unlock(&fi->fi_ast_lock);
694
695 /* Work out the size of the returned data */
696 data_size = sizeof(struct dlm_lock_result);
697 if (ast->lvb_updated && ast->result.lksb.sb_lvbptr)
698 data_size += DLM_USER_LVB_LEN;
699
700 offset = sizeof(struct dlm_lock_result);
701
702 /* Room for the extended data ? */
703 if (count >= data_size) {
704
705 if (ast->lvb_updated && ast->result.lksb.sb_lvbptr) {
706 if (copy_to_user(buffer+offset,
707 ast->result.lksb.sb_lvbptr,
708 DLM_USER_LVB_LEN))
709 return -EFAULT;
710 ast->result.lvb_offset = offset;
711 offset += DLM_USER_LVB_LEN;
712 }
713 }
714
715 ast->result.length = data_size;
716 /* Copy the header now it has all the offsets in it */
717 if (copy_to_user(buffer, &ast->result, sizeof(struct dlm_lock_result)))
718 offset = -EFAULT;
719
720 /* If we only returned a header and there's more to come then put it
721 back on the list */
722 if (count < data_size) {
723 spin_lock(&fi->fi_ast_lock);
724 list_add(&ast->list, &fi->fi_ast_list);
725 spin_unlock(&fi->fi_ast_lock);
726 } else
727 kfree(ast);
728 return offset;
729}
730
731static unsigned int dlm_poll(struct file *file, poll_table *wait)
732{
733 struct file_info *fi = file->private_data;
734
735 poll_wait(file, &fi->fi_wait, wait);
736
737 spin_lock(&fi->fi_ast_lock);
738 if (!list_empty(&fi->fi_ast_list)) {
739 spin_unlock(&fi->fi_ast_lock);
740 return POLLIN | POLLRDNORM;
741 }
742
743 spin_unlock(&fi->fi_ast_lock);
744 return 0;
745}
746
747static struct lock_info *allocate_lockinfo(struct file_info *fi, uint8_t cmd,
748 struct dlm_lock_params *kparams)
749{
750 struct lock_info *li;
751
752 if (!try_module_get(THIS_MODULE))
753 return NULL;
754
755 li = kmalloc(sizeof(struct lock_info), GFP_KERNEL);
756 if (li) {
757 li->li_magic = LOCKINFO_MAGIC;
758 li->li_file = fi;
759 li->li_cmd = cmd;
760 li->li_flags = 0;
761 li->li_grmode = -1;
762 li->li_rqmode = -1;
763 li->li_pend_bastparam = NULL;
764 li->li_pend_bastaddr = NULL;
765 li->li_castaddr = NULL;
766 li->li_castparam = NULL;
767 li->li_lksb.sb_lvbptr = NULL;
768 li->li_bastaddr = kparams->bastaddr;
769 li->li_bastparam = kparams->bastparam;
770
771 get_file_info(fi);
772 }
773 return li;
774}
775
776static int do_user_lock(struct file_info *fi, uint8_t cmd,
777 struct dlm_lock_params *kparams)
778{
779 struct lock_info *li;
780 int status;
781
782 /*
783 * Validate things that we need to have correct.
784 */
785 if (!kparams->castaddr)
786 return -EINVAL;
787
788 if (!kparams->lksb)
789 return -EINVAL;
790
791 /* Persistent child locks are not available yet */
792 if ((kparams->flags & DLM_LKF_PERSISTENT) && kparams->parent)
793 return -EINVAL;
794
795 /* For conversions, there should already be a lockinfo struct,
796 unless we are adopting an orphaned persistent lock */
797 if (kparams->flags & DLM_LKF_CONVERT) {
798
799 li = get_lockinfo(kparams->lkid);
800
801 /* If this is a persistent lock we will have to create a
802 lockinfo again */
803 if (!li && DLM_LKF_PERSISTENT) {
804 li = allocate_lockinfo(fi, cmd, kparams);
805
806 li->li_lksb.sb_lkid = kparams->lkid;
807 li->li_castaddr = kparams->castaddr;
808 li->li_castparam = kparams->castparam;
809
810 /* OK, this isn;t exactly a FIRSTLOCK but it is the
811 first time we've used this lockinfo, and if things
812 fail we want rid of it */
813 init_MUTEX_LOCKED(&li->li_firstlock);
814 set_bit(LI_FLAG_FIRSTLOCK, &li->li_flags);
815 add_lockinfo(li);
816
817 /* TODO: do a query to get the current state ?? */
818 }
819 if (!li)
820 return -EINVAL;
821
822 if (li->li_magic != LOCKINFO_MAGIC)
823 return -EINVAL;
824
825 /* For conversions don't overwrite the current blocking AST
826 info so that:
827 a) if a blocking AST fires before the conversion is queued
828 it runs the current handler
829 b) if the conversion is cancelled, the original blocking AST
830 declaration is active
831 The pend_ info is made active when the conversion
832 completes.
833 */
834 li->li_pend_bastaddr = kparams->bastaddr;
835 li->li_pend_bastparam = kparams->bastparam;
836 } else {
837 li = allocate_lockinfo(fi, cmd, kparams);
838 if (!li)
839 return -ENOMEM;
840
841 /* semaphore to allow us to complete our work before
842 the AST routine runs. In fact we only need (and use) this
843 when the initial lock fails */
844 init_MUTEX_LOCKED(&li->li_firstlock);
845 set_bit(LI_FLAG_FIRSTLOCK, &li->li_flags);
846 }
847
848 li->li_user_lksb = kparams->lksb;
849 li->li_castaddr = kparams->castaddr;
850 li->li_castparam = kparams->castparam;
851 li->li_lksb.sb_lkid = kparams->lkid;
852 li->li_rqmode = kparams->mode;
853 if (kparams->flags & DLM_LKF_PERSISTENT)
854 set_bit(LI_FLAG_PERSISTENT, &li->li_flags);
855
856 /* Copy in the value block */
857 if (kparams->flags & DLM_LKF_VALBLK) {
858 if (!li->li_lksb.sb_lvbptr) {
859 li->li_lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN,
860 GFP_KERNEL);
861 if (!li->li_lksb.sb_lvbptr) {
862 status = -ENOMEM;
863 goto out_err;
864 }
865 }
866
867 memcpy(li->li_lksb.sb_lvbptr, kparams->lvb, DLM_USER_LVB_LEN);
868 }
869
870 /* Lock it ... */
871 status = dlm_lock(fi->fi_ls->ls_lockspace,
872 kparams->mode, &li->li_lksb,
873 kparams->flags,
874 kparams->name, kparams->namelen,
875 kparams->parent,
876 ast_routine,
877 li,
878 (li->li_pend_bastaddr || li->li_bastaddr) ?
879 bast_routine : NULL,
880 kparams->range.ra_end ? &kparams->range : NULL);
881 if (status)
882 goto out_err;
883
884 /* If it succeeded (this far) with a new lock then keep track of
885 it on the file's lockinfo list */
886 if (!status && test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags)) {
887
888 spin_lock(&fi->fi_li_lock);
889 list_add(&li->li_ownerqueue, &fi->fi_li_list);
890 spin_unlock(&fi->fi_li_lock);
891 if (add_lockinfo(li))
892 printk(KERN_WARNING "Add lockinfo failed\n");
893
894 up(&li->li_firstlock);
895 }
896
897 /* Return the lockid as the user needs it /now/ */
898 return li->li_lksb.sb_lkid;
899
900 out_err:
901 if (test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags))
902 release_lockinfo(li);
903 return status;
904
905}
906
907static int do_user_unlock(struct file_info *fi, uint8_t cmd,
908 struct dlm_lock_params *kparams)
909{
910 struct lock_info *li;
911 int status;
912 int convert_cancel = 0;
913
914 li = get_lockinfo(kparams->lkid);
915 if (!li) {
916 li = allocate_lockinfo(fi, cmd, kparams);
917 spin_lock(&fi->fi_li_lock);
918 list_add(&li->li_ownerqueue, &fi->fi_li_list);
919 spin_unlock(&fi->fi_li_lock);
920 }
921 if (!li)
922 return -ENOMEM;
923
924 if (li->li_magic != LOCKINFO_MAGIC)
925 return -EINVAL;
926
927 li->li_user_lksb = kparams->lksb;
928 li->li_castparam = kparams->castparam;
929 li->li_cmd = cmd;
930
931 /* Cancelling a conversion doesn't remove the lock...*/
932 if (kparams->flags & DLM_LKF_CANCEL && li->li_grmode != -1)
933 convert_cancel = 1;
934
935 /* dlm_unlock() passes a 0 for castaddr which means don't overwrite
936 the existing li_castaddr as that's the completion routine for
937 unlocks. dlm_unlock_wait() specifies a new AST routine to be
938 executed when the unlock completes. */
939 if (kparams->castaddr)
940 li->li_castaddr = kparams->castaddr;
941
942 /* Use existing lksb & astparams */
943 status = dlm_unlock(fi->fi_ls->ls_lockspace,
944 kparams->lkid,
945 kparams->flags, &li->li_lksb, li);
946
947 if (!status && !convert_cancel) {
948 spin_lock(&fi->fi_li_lock);
949 list_del(&li->li_ownerqueue);
950 spin_unlock(&fi->fi_li_lock);
951 }
952
953 return status;
954}
955
956/* Write call, submit a locking request */
957static ssize_t dlm_write(struct file *file, const char __user *buffer,
958 size_t count, loff_t *ppos)
959{
960 struct file_info *fi = file->private_data;
961 struct dlm_write_request *kparams;
962 sigset_t tmpsig;
963 sigset_t allsigs;
964 int status;
965
966 /* -1 because lock name is optional */
967 if (count < sizeof(struct dlm_write_request)-1)
968 return -EINVAL;
969
970 /* Has the lockspace been deleted */
971 if (fi && test_bit(LS_FLAG_DELETED, &fi->fi_ls->ls_flags))
972 return -ENOENT;
973
974 kparams = kmalloc(count, GFP_KERNEL);
975 if (!kparams)
976 return -ENOMEM;
977
978 status = -EFAULT;
979 /* Get the command info */
980 if (copy_from_user(kparams, buffer, count))
981 goto out_free;
982
983 status = -EBADE;
984 if (check_version(kparams))
985 goto out_free;
986
987 /* Block signals while we are doing this */
988 sigfillset(&allsigs);
989 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
990
991 status = -EINVAL;
992 switch (kparams->cmd)
993 {
994 case DLM_USER_LOCK:
995 if (!fi) goto out_sig;
996 status = do_user_lock(fi, kparams->cmd, &kparams->i.lock);
997 break;
998
999 case DLM_USER_UNLOCK:
1000 if (!fi) goto out_sig;
1001 status = do_user_unlock(fi, kparams->cmd, &kparams->i.lock);
1002 break;
1003
1004 case DLM_USER_CREATE_LOCKSPACE:
1005 if (fi) goto out_sig;
1006 status = do_user_create_lockspace(fi, kparams->cmd,
1007 &kparams->i.lspace);
1008 break;
1009
1010 case DLM_USER_REMOVE_LOCKSPACE:
1011 if (fi) goto out_sig;
1012 status = do_user_remove_lockspace(fi, kparams->cmd,
1013 &kparams->i.lspace);
1014 break;
1015 default:
1016 printk("Unknown command passed to DLM device : %d\n",
1017 kparams->cmd);
1018 break;
1019 }
1020
1021 out_sig:
1022 /* Restore signals */
1023 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
1024 recalc_sigpending();
1025
1026 out_free:
1027 kfree(kparams);
1028 if (status == 0)
1029 return count;
1030 else
1031 return status;
1032}
1033
1034static struct file_operations _dlm_fops = {
1035 .open = dlm_open,
1036 .release = dlm_close,
1037 .read = dlm_read,
1038 .write = dlm_write,
1039 .poll = dlm_poll,
1040 .owner = THIS_MODULE,
1041};
1042
1043static struct file_operations _dlm_ctl_fops = {
1044 .open = dlm_ctl_open,
1045 .release = dlm_ctl_close,
1046 .write = dlm_write,
1047 .owner = THIS_MODULE,
1048};
1049
1050/*
1051 * Create control device
1052 */
1053static int __init dlm_device_init(void)
1054{
1055 int r;
1056
1057 INIT_LIST_HEAD(&user_ls_list);
1058 init_MUTEX(&user_ls_lock);
1059 rwlock_init(&lockinfo_lock);
1060
1061 ctl_device.name = "dlm-control";
1062 ctl_device.fops = &_dlm_ctl_fops;
1063 ctl_device.minor = MISC_DYNAMIC_MINOR;
1064
1065 r = misc_register(&ctl_device);
1066 if (r) {
1067 printk(KERN_ERR "dlm: misc_register failed for control dev\n");
1068 return r;
1069 }
1070
1071 return 0;
1072}
1073
1074static void __exit dlm_device_exit(void)
1075{
1076 misc_deregister(&ctl_device);
1077}
1078
1079MODULE_DESCRIPTION("Distributed Lock Manager device interface");
1080MODULE_AUTHOR("Red Hat, Inc.");
1081MODULE_LICENSE("GPL");
1082
1083module_init(dlm_device_init);
1084module_exit(dlm_device_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 09:19:14 -0500