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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#include "ast.h"
28
29static const char name_prefix[] = "dlm";
30static const struct file_operations device_fops;
31static atomic_t dlm_monitor_opened;
32static int dlm_monitor_unused = 1;
33
34#ifdef CONFIG_COMPAT
35
36struct dlm_lock_params32 {
37 __u8 mode;
38 __u8 namelen;
39 __u16 unused;
40 __u32 flags;
41 __u32 lkid;
42 __u32 parent;
43 __u64 xid;
44 __u64 timeout;
45 __u32 castparam;
46 __u32 castaddr;
47 __u32 bastparam;
48 __u32 bastaddr;
49 __u32 lksb;
50 char lvb[DLM_USER_LVB_LEN];
51 char name[0];
52};
53
54struct dlm_write_request32 {
55 __u32 version[3];
56 __u8 cmd;
57 __u8 is64bit;
58 __u8 unused[2];
59
60 union {
61 struct dlm_lock_params32 lock;
62 struct dlm_lspace_params lspace;
63 struct dlm_purge_params purge;
64 } i;
65};
66
67struct dlm_lksb32 {
68 __u32 sb_status;
69 __u32 sb_lkid;
70 __u8 sb_flags;
71 __u32 sb_lvbptr;
72};
73
74struct dlm_lock_result32 {
75 __u32 version[3];
76 __u32 length;
77 __u32 user_astaddr;
78 __u32 user_astparam;
79 __u32 user_lksb;
80 struct dlm_lksb32 lksb;
81 __u8 bast_mode;
82 __u8 unused[3];
83 /* Offsets may be zero if no data is present */
84 __u32 lvb_offset;
85};
86
87static void compat_input(struct dlm_write_request *kb,
88 struct dlm_write_request32 *kb32,
89 int namelen)
90{
91 kb->version[0] = kb32->version[0];
92 kb->version[1] = kb32->version[1];
93 kb->version[2] = kb32->version[2];
94
95 kb->cmd = kb32->cmd;
96 kb->is64bit = kb32->is64bit;
97 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
98 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
99 kb->i.lspace.flags = kb32->i.lspace.flags;
100 kb->i.lspace.minor = kb32->i.lspace.minor;
101 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
102 } else if (kb->cmd == DLM_USER_PURGE) {
103 kb->i.purge.nodeid = kb32->i.purge.nodeid;
104 kb->i.purge.pid = kb32->i.purge.pid;
105 } else {
106 kb->i.lock.mode = kb32->i.lock.mode;
107 kb->i.lock.namelen = kb32->i.lock.namelen;
108 kb->i.lock.flags = kb32->i.lock.flags;
109 kb->i.lock.lkid = kb32->i.lock.lkid;
110 kb->i.lock.parent = kb32->i.lock.parent;
111 kb->i.lock.xid = kb32->i.lock.xid;
112 kb->i.lock.timeout = kb32->i.lock.timeout;
113 kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
114 kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
115 kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
116 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
117 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
118 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
119 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
120 }
121}
122
123static void compat_output(struct dlm_lock_result *res,
124 struct dlm_lock_result32 *res32)
125{
126 res32->version[0] = res->version[0];
127 res32->version[1] = res->version[1];
128 res32->version[2] = res->version[2];
129
130 res32->user_astaddr = (__u32)(long)res->user_astaddr;
131 res32->user_astparam = (__u32)(long)res->user_astparam;
132 res32->user_lksb = (__u32)(long)res->user_lksb;
133 res32->bast_mode = res->bast_mode;
134
135 res32->lvb_offset = res->lvb_offset;
136 res32->length = res->length;
137
138 res32->lksb.sb_status = res->lksb.sb_status;
139 res32->lksb.sb_flags = res->lksb.sb_flags;
140 res32->lksb.sb_lkid = res->lksb.sb_lkid;
141 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
142}
143#endif
144
145/* Figure out if this lock is at the end of its life and no longer
146 available for the application to use. The lkb still exists until
147 the final ast is read. A lock becomes EOL in three situations:
148 1. a noqueue request fails with EAGAIN
149 2. an unlock completes with EUNLOCK
150 3. a cancel of a waiting request completes with ECANCEL/EDEADLK
151 An EOL lock needs to be removed from the process's list of locks.
152 And we can't allow any new operation on an EOL lock. This is
153 not related to the lifetime of the lkb struct which is managed
154 entirely by refcount. */
155
156static int lkb_is_endoflife(int mode, int status)
157{
158 switch (status) {
159 case -DLM_EUNLOCK:
160 return 1;
161 case -DLM_ECANCEL:
162 case -ETIMEDOUT:
163 case -EDEADLK:
164 case -EAGAIN:
165 if (mode == DLM_LOCK_IV)
166 return 1;
167 break;
168 }
169 return 0;
170}
171
172/* we could possibly check if the cancel of an orphan has resulted in the lkb
173 being removed and then remove that lkb from the orphans list and free it */
174
175void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
176 int status, uint32_t sbflags, uint64_t seq)
177{
178 struct dlm_ls *ls;
179 struct dlm_user_args *ua;
180 struct dlm_user_proc *proc;
181 int rv;
182
183 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
184 return;
185
186 ls = lkb->lkb_resource->res_ls;
187 mutex_lock(&ls->ls_clear_proc_locks);
188
189 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
190 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
191 lkb->ua so we can't try to use it. This second check is necessary
192 for cases where a completion ast is received for an operation that
193 began before clear_proc_locks did its cancel/unlock. */
194
195 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
196 goto out;
197
198 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
199 ua = lkb->lkb_ua;
200 proc = ua->proc;
201
202 if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
203 goto out;
204
205 if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
206 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
207
208 spin_lock(&proc->asts_spin);
209
210 rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
211 if (rv < 0) {
212 spin_unlock(&proc->asts_spin);
213 goto out;
214 }
215
216 if (list_empty(&lkb->lkb_cb_list)) {
217 kref_get(&lkb->lkb_ref);
218 list_add_tail(&lkb->lkb_cb_list, &proc->asts);
219 wake_up_interruptible(&proc->wait);
220 }
221 spin_unlock(&proc->asts_spin);
222
223 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
224 /* N.B. spin_lock locks_spin, not asts_spin */
225 spin_lock(&proc->locks_spin);
226 if (!list_empty(&lkb->lkb_ownqueue)) {
227 list_del_init(&lkb->lkb_ownqueue);
228 dlm_put_lkb(lkb);
229 }
230 spin_unlock(&proc->locks_spin);
231 }
232 out:
233 mutex_unlock(&ls->ls_clear_proc_locks);
234}
235
236static int device_user_lock(struct dlm_user_proc *proc,
237 struct dlm_lock_params *params)
238{
239 struct dlm_ls *ls;
240 struct dlm_user_args *ua;
241 int error = -ENOMEM;
242
243 ls = dlm_find_lockspace_local(proc->lockspace);
244 if (!ls)
245 return -ENOENT;
246
247 if (!params->castaddr || !params->lksb) {
248 error = -EINVAL;
249 goto out;
250 }
251
252 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
253 if (!ua)
254 goto out;
255 ua->proc = proc;
256 ua->user_lksb = params->lksb;
257 ua->castparam = params->castparam;
258 ua->castaddr = params->castaddr;
259 ua->bastparam = params->bastparam;
260 ua->bastaddr = params->bastaddr;
261 ua->xid = params->xid;
262
263 if (params->flags & DLM_LKF_CONVERT)
264 error = dlm_user_convert(ls, ua,
265 params->mode, params->flags,
266 params->lkid, params->lvb,
267 (unsigned long) params->timeout);
268 else {
269 error = dlm_user_request(ls, ua,
270 params->mode, params->flags,
271 params->name, params->namelen,
272 (unsigned long) params->timeout);
273 if (!error)
274 error = ua->lksb.sb_lkid;
275 }
276 out:
277 dlm_put_lockspace(ls);
278 return error;
279}
280
281static int device_user_unlock(struct dlm_user_proc *proc,
282 struct dlm_lock_params *params)
283{
284 struct dlm_ls *ls;
285 struct dlm_user_args *ua;
286 int error = -ENOMEM;
287
288 ls = dlm_find_lockspace_local(proc->lockspace);
289 if (!ls)
290 return -ENOENT;
291
292 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
293 if (!ua)
294 goto out;
295 ua->proc = proc;
296 ua->user_lksb = params->lksb;
297 ua->castparam = params->castparam;
298 ua->castaddr = params->castaddr;
299
300 if (params->flags & DLM_LKF_CANCEL)
301 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
302 else
303 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
304 params->lvb);
305 out:
306 dlm_put_lockspace(ls);
307 return error;
308}
309
310static int device_user_deadlock(struct dlm_user_proc *proc,
311 struct dlm_lock_params *params)
312{
313 struct dlm_ls *ls;
314 int error;
315
316 ls = dlm_find_lockspace_local(proc->lockspace);
317 if (!ls)
318 return -ENOENT;
319
320 error = dlm_user_deadlock(ls, params->flags, params->lkid);
321
322 dlm_put_lockspace(ls);
323 return error;
324}
325
326static int dlm_device_register(struct dlm_ls *ls, char *name)
327{
328 int error, len;
329
330 /* The device is already registered. This happens when the
331 lockspace is created multiple times from userspace. */
332 if (ls->ls_device.name)
333 return 0;
334
335 error = -ENOMEM;
336 len = strlen(name) + strlen(name_prefix) + 2;
337 ls->ls_device.name = kzalloc(len, GFP_NOFS);
338 if (!ls->ls_device.name)
339 goto fail;
340
341 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
342 name);
343 ls->ls_device.fops = &device_fops;
344 ls->ls_device.minor = MISC_DYNAMIC_MINOR;
345
346 error = misc_register(&ls->ls_device);
347 if (error) {
348 kfree(ls->ls_device.name);
349 }
350fail:
351 return error;
352}
353
354int dlm_device_deregister(struct dlm_ls *ls)
355{
356 int error;
357
358 /* The device is not registered. This happens when the lockspace
359 was never used from userspace, or when device_create_lockspace()
360 calls dlm_release_lockspace() after the register fails. */
361 if (!ls->ls_device.name)
362 return 0;
363
364 error = misc_deregister(&ls->ls_device);
365 if (!error)
366 kfree(ls->ls_device.name);
367 return error;
368}
369
370static int device_user_purge(struct dlm_user_proc *proc,
371 struct dlm_purge_params *params)
372{
373 struct dlm_ls *ls;
374 int error;
375
376 ls = dlm_find_lockspace_local(proc->lockspace);
377 if (!ls)
378 return -ENOENT;
379
380 error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
381
382 dlm_put_lockspace(ls);
383 return error;
384}
385
386static int device_create_lockspace(struct dlm_lspace_params *params)
387{
388 dlm_lockspace_t *lockspace;
389 struct dlm_ls *ls;
390 int error;
391
392 if (!capable(CAP_SYS_ADMIN))
393 return -EPERM;
394
395 error = dlm_new_lockspace(params->name, strlen(params->name),
396 &lockspace, params->flags, DLM_USER_LVB_LEN);
397 if (error)
398 return error;
399
400 ls = dlm_find_lockspace_local(lockspace);
401 if (!ls)
402 return -ENOENT;
403
404 error = dlm_device_register(ls, params->name);
405 dlm_put_lockspace(ls);
406
407 if (error)
408 dlm_release_lockspace(lockspace, 0);
409 else
410 error = ls->ls_device.minor;
411
412 return error;
413}
414
415static int device_remove_lockspace(struct dlm_lspace_params *params)
416{
417 dlm_lockspace_t *lockspace;
418 struct dlm_ls *ls;
419 int error, force = 0;
420
421 if (!capable(CAP_SYS_ADMIN))
422 return -EPERM;
423
424 ls = dlm_find_lockspace_device(params->minor);
425 if (!ls)
426 return -ENOENT;
427
428 if (params->flags & DLM_USER_LSFLG_FORCEFREE)
429 force = 2;
430
431 lockspace = ls->ls_local_handle;
432 dlm_put_lockspace(ls);
433
434 /* The final dlm_release_lockspace waits for references to go to
435 zero, so all processes will need to close their device for the
436 ls before the release will proceed. release also calls the
437 device_deregister above. Converting a positive return value
438 from release to zero means that userspace won't know when its
439 release was the final one, but it shouldn't need to know. */
440
441 error = dlm_release_lockspace(lockspace, force);
442 if (error > 0)
443 error = 0;
444 return error;
445}
446
447/* Check the user's version matches ours */
448static int check_version(struct dlm_write_request *req)
449{
450 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
451 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
452 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
453
454 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
455 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
456 current->comm,
457 task_pid_nr(current),
458 req->version[0],
459 req->version[1],
460 req->version[2],
461 DLM_DEVICE_VERSION_MAJOR,
462 DLM_DEVICE_VERSION_MINOR,
463 DLM_DEVICE_VERSION_PATCH);
464 return -EINVAL;
465 }
466 return 0;
467}
468
469/*
470 * device_write
471 *
472 * device_user_lock
473 * dlm_user_request -> request_lock
474 * dlm_user_convert -> convert_lock
475 *
476 * device_user_unlock
477 * dlm_user_unlock -> unlock_lock
478 * dlm_user_cancel -> cancel_lock
479 *
480 * device_create_lockspace
481 * dlm_new_lockspace
482 *
483 * device_remove_lockspace
484 * dlm_release_lockspace
485 */
486
487/* a write to a lockspace device is a lock or unlock request, a write
488 to the control device is to create/remove a lockspace */
489
490static ssize_t device_write(struct file *file, const char __user *buf,
491 size_t count, loff_t *ppos)
492{
493 struct dlm_user_proc *proc = file->private_data;
494 struct dlm_write_request *kbuf;
495 sigset_t tmpsig, allsigs;
496 int error;
497
498#ifdef CONFIG_COMPAT
499 if (count < sizeof(struct dlm_write_request32))
500#else
501 if (count < sizeof(struct dlm_write_request))
502#endif
503 return -EINVAL;
504
505 kbuf = kzalloc(count + 1, GFP_NOFS);
506 if (!kbuf)
507 return -ENOMEM;
508
509 if (copy_from_user(kbuf, buf, count)) {
510 error = -EFAULT;
511 goto out_free;
512 }
513
514 if (check_version(kbuf)) {
515 error = -EBADE;
516 goto out_free;
517 }
518
519#ifdef CONFIG_COMPAT
520 if (!kbuf->is64bit) {
521 struct dlm_write_request32 *k32buf;
522 int namelen = 0;
523
524 if (count > sizeof(struct dlm_write_request32))
525 namelen = count - sizeof(struct dlm_write_request32);
526
527 k32buf = (struct dlm_write_request32 *)kbuf;
528
529 /* add 1 after namelen so that the name string is terminated */
530 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
531 GFP_NOFS);
532 if (!kbuf) {
533 kfree(k32buf);
534 return -ENOMEM;
535 }
536
537 if (proc)
538 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
539
540 compat_input(kbuf, k32buf, namelen);
541 kfree(k32buf);
542 }
543#endif
544
545 /* do we really need this? can a write happen after a close? */
546 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
547 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
548 error = -EINVAL;
549 goto out_free;
550 }
551
552 sigfillset(&allsigs);
553 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
554
555 error = -EINVAL;
556
557 switch (kbuf->cmd)
558 {
559 case DLM_USER_LOCK:
560 if (!proc) {
561 log_print("no locking on control device");
562 goto out_sig;
563 }
564 error = device_user_lock(proc, &kbuf->i.lock);
565 break;
566
567 case DLM_USER_UNLOCK:
568 if (!proc) {
569 log_print("no locking on control device");
570 goto out_sig;
571 }
572 error = device_user_unlock(proc, &kbuf->i.lock);
573 break;
574
575 case DLM_USER_DEADLOCK:
576 if (!proc) {
577 log_print("no locking on control device");
578 goto out_sig;
579 }
580 error = device_user_deadlock(proc, &kbuf->i.lock);
581 break;
582
583 case DLM_USER_CREATE_LOCKSPACE:
584 if (proc) {
585 log_print("create/remove only on control device");
586 goto out_sig;
587 }
588 error = device_create_lockspace(&kbuf->i.lspace);
589 break;
590
591 case DLM_USER_REMOVE_LOCKSPACE:
592 if (proc) {
593 log_print("create/remove only on control device");
594 goto out_sig;
595 }
596 error = device_remove_lockspace(&kbuf->i.lspace);
597 break;
598
599 case DLM_USER_PURGE:
600 if (!proc) {
601 log_print("no locking on control device");
602 goto out_sig;
603 }
604 error = device_user_purge(proc, &kbuf->i.purge);
605 break;
606
607 default:
608 log_print("Unknown command passed to DLM device : %d\n",
609 kbuf->cmd);
610 }
611
612 out_sig:
613 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
614 out_free:
615 kfree(kbuf);
616 return error;
617}
618
619/* Every process that opens the lockspace device has its own "proc" structure
620 hanging off the open file that's used to keep track of locks owned by the
621 process and asts that need to be delivered to the process. */
622
623static int device_open(struct inode *inode, struct file *file)
624{
625 struct dlm_user_proc *proc;
626 struct dlm_ls *ls;
627
628 ls = dlm_find_lockspace_device(iminor(inode));
629 if (!ls)
630 return -ENOENT;
631
632 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
633 if (!proc) {
634 dlm_put_lockspace(ls);
635 return -ENOMEM;
636 }
637
638 proc->lockspace = ls->ls_local_handle;
639 INIT_LIST_HEAD(&proc->asts);
640 INIT_LIST_HEAD(&proc->locks);
641 INIT_LIST_HEAD(&proc->unlocking);
642 spin_lock_init(&proc->asts_spin);
643 spin_lock_init(&proc->locks_spin);
644 init_waitqueue_head(&proc->wait);
645 file->private_data = proc;
646
647 return 0;
648}
649
650static int device_close(struct inode *inode, struct file *file)
651{
652 struct dlm_user_proc *proc = file->private_data;
653 struct dlm_ls *ls;
654 sigset_t tmpsig, allsigs;
655
656 ls = dlm_find_lockspace_local(proc->lockspace);
657 if (!ls)
658 return -ENOENT;
659
660 sigfillset(&allsigs);
661 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
662
663 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
664
665 dlm_clear_proc_locks(ls, proc);
666
667 /* at this point no more lkb's should exist for this lockspace,
668 so there's no chance of dlm_user_add_ast() being called and
669 looking for lkb->ua->proc */
670
671 kfree(proc);
672 file->private_data = NULL;
673
674 dlm_put_lockspace(ls);
675 dlm_put_lockspace(ls); /* for the find in device_open() */
676
677 /* FIXME: AUTOFREE: if this ls is no longer used do
678 device_remove_lockspace() */
679
680 sigprocmask(SIG_SETMASK, &tmpsig, NULL);
681 recalc_sigpending();
682
683 return 0;
684}
685
686static int copy_result_to_user(struct dlm_user_args *ua, int compat,
687 uint32_t flags, int mode, int copy_lvb,
688 char __user *buf, size_t count)
689{
690#ifdef CONFIG_COMPAT
691 struct dlm_lock_result32 result32;
692#endif
693 struct dlm_lock_result result;
694 void *resultptr;
695 int error=0;
696 int len;
697 int struct_len;
698
699 memset(&result, 0, sizeof(struct dlm_lock_result));
700 result.version[0] = DLM_DEVICE_VERSION_MAJOR;
701 result.version[1] = DLM_DEVICE_VERSION_MINOR;
702 result.version[2] = DLM_DEVICE_VERSION_PATCH;
703 memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb));
704 result.user_lksb = ua->user_lksb;
705
706 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
707 in a conversion unless the conversion is successful. See code
708 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though,
709 notes that a new blocking AST address and parameter are set even if
710 the conversion fails, so maybe we should just do that. */
711
712 if (flags & DLM_CB_BAST) {
713 result.user_astaddr = ua->bastaddr;
714 result.user_astparam = ua->bastparam;
715 result.bast_mode = mode;
716 } else {
717 result.user_astaddr = ua->castaddr;
718 result.user_astparam = ua->castparam;
719 }
720
721#ifdef CONFIG_COMPAT
722 if (compat)
723 len = sizeof(struct dlm_lock_result32);
724 else
725#endif
726 len = sizeof(struct dlm_lock_result);
727 struct_len = len;
728
729 /* copy lvb to userspace if there is one, it's been updated, and
730 the user buffer has space for it */
731
732 if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
733 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
734 DLM_USER_LVB_LEN)) {
735 error = -EFAULT;
736 goto out;
737 }
738
739 result.lvb_offset = len;
740 len += DLM_USER_LVB_LEN;
741 }
742
743 result.length = len;
744 resultptr = &result;
745#ifdef CONFIG_COMPAT
746 if (compat) {
747 compat_output(&result, &result32);
748 resultptr = &result32;
749 }
750#endif
751
752 if (copy_to_user(buf, resultptr, struct_len))
753 error = -EFAULT;
754 else
755 error = len;
756 out:
757 return error;
758}
759
760static int copy_version_to_user(char __user *buf, size_t count)
761{
762 struct dlm_device_version ver;
763
764 memset(&ver, 0, sizeof(struct dlm_device_version));
765 ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
766 ver.version[1] = DLM_DEVICE_VERSION_MINOR;
767 ver.version[2] = DLM_DEVICE_VERSION_PATCH;
768
769 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
770 return -EFAULT;
771 return sizeof(struct dlm_device_version);
772}
773
774/* a read returns a single ast described in a struct dlm_lock_result */
775
776static ssize_t device_read(struct file *file, char __user *buf, size_t count,
777 loff_t *ppos)
778{
779 struct dlm_user_proc *proc = file->private_data;
780 struct dlm_lkb *lkb;
781 DECLARE_WAITQUEUE(wait, current);
782 struct dlm_callback cb;
783 int rv, resid, copy_lvb = 0;
784
785 if (count == sizeof(struct dlm_device_version)) {
786 rv = copy_version_to_user(buf, count);
787 return rv;
788 }
789
790 if (!proc) {
791 log_print("non-version read from control device %zu", count);
792 return -EINVAL;
793 }
794
795#ifdef CONFIG_COMPAT
796 if (count < sizeof(struct dlm_lock_result32))
797#else
798 if (count < sizeof(struct dlm_lock_result))
799#endif
800 return -EINVAL;
801
802 try_another:
803
804 /* do we really need this? can a read happen after a close? */
805 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
806 return -EINVAL;
807
808 spin_lock(&proc->asts_spin);
809 if (list_empty(&proc->asts)) {
810 if (file->f_flags & O_NONBLOCK) {
811 spin_unlock(&proc->asts_spin);
812 return -EAGAIN;
813 }
814
815 add_wait_queue(&proc->wait, &wait);
816
817 repeat:
818 set_current_state(TASK_INTERRUPTIBLE);
819 if (list_empty(&proc->asts) && !signal_pending(current)) {
820 spin_unlock(&proc->asts_spin);
821 schedule();
822 spin_lock(&proc->asts_spin);
823 goto repeat;
824 }
825 set_current_state(TASK_RUNNING);
826 remove_wait_queue(&proc->wait, &wait);
827
828 if (signal_pending(current)) {
829 spin_unlock(&proc->asts_spin);
830 return -ERESTARTSYS;
831 }
832 }
833
834 /* if we empty lkb_callbacks, we don't want to unlock the spinlock
835 without removing lkb_cb_list; so empty lkb_cb_list is always
836 consistent with empty lkb_callbacks */
837
838 lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_cb_list);
839
840 rv = dlm_rem_lkb_callback(lkb->lkb_resource->res_ls, lkb, &cb, &resid);
841 if (rv < 0) {
842 /* this shouldn't happen; lkb should have been removed from
843 list when resid was zero */
844 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
845 list_del_init(&lkb->lkb_cb_list);
846 spin_unlock(&proc->asts_spin);
847 /* removes ref for proc->asts, may cause lkb to be freed */
848 dlm_put_lkb(lkb);
849 goto try_another;
850 }
851 if (!resid)
852 list_del_init(&lkb->lkb_cb_list);
853 spin_unlock(&proc->asts_spin);
854
855 if (cb.flags & DLM_CB_SKIP) {
856 /* removes ref for proc->asts, may cause lkb to be freed */
857 if (!resid)
858 dlm_put_lkb(lkb);
859 goto try_another;
860 }
861
862 if (cb.flags & DLM_CB_CAST) {
863 int old_mode, new_mode;
864
865 old_mode = lkb->lkb_last_cast.mode;
866 new_mode = cb.mode;
867
868 if (!cb.sb_status && lkb->lkb_lksb->sb_lvbptr &&
869 dlm_lvb_operations[old_mode + 1][new_mode + 1])
870 copy_lvb = 1;
871
872 lkb->lkb_lksb->sb_status = cb.sb_status;
873 lkb->lkb_lksb->sb_flags = cb.sb_flags;
874 }
875
876 rv = copy_result_to_user(lkb->lkb_ua,
877 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
878 cb.flags, cb.mode, copy_lvb, buf, count);
879
880 /* removes ref for proc->asts, may cause lkb to be freed */
881 if (!resid)
882 dlm_put_lkb(lkb);
883
884 return rv;
885}
886
887static unsigned int device_poll(struct file *file, poll_table *wait)
888{
889 struct dlm_user_proc *proc = file->private_data;
890
891 poll_wait(file, &proc->wait, wait);
892
893 spin_lock(&proc->asts_spin);
894 if (!list_empty(&proc->asts)) {
895 spin_unlock(&proc->asts_spin);
896 return POLLIN | POLLRDNORM;
897 }
898 spin_unlock(&proc->asts_spin);
899 return 0;
900}
901
902int dlm_user_daemon_available(void)
903{
904 /* dlm_controld hasn't started (or, has started, but not
905 properly populated configfs) */
906
907 if (!dlm_our_nodeid())
908 return 0;
909
910 /* This is to deal with versions of dlm_controld that don't
911 know about the monitor device. We assume that if the
912 dlm_controld was started (above), but the monitor device
913 was never opened, that it's an old version. dlm_controld
914 should open the monitor device before populating configfs. */
915
916 if (dlm_monitor_unused)
917 return 1;
918
919 return atomic_read(&dlm_monitor_opened) ? 1 : 0;
920}
921
922static int ctl_device_open(struct inode *inode, struct file *file)
923{
924 file->private_data = NULL;
925 return 0;
926}
927
928static int ctl_device_close(struct inode *inode, struct file *file)
929{
930 return 0;
931}
932
933static int monitor_device_open(struct inode *inode, struct file *file)
934{
935 atomic_inc(&dlm_monitor_opened);
936 dlm_monitor_unused = 0;
937 return 0;
938}
939
940static int monitor_device_close(struct inode *inode, struct file *file)
941{
942 if (atomic_dec_and_test(&dlm_monitor_opened))
943 dlm_stop_lockspaces();
944 return 0;
945}
946
947static const struct file_operations device_fops = {
948 .open = device_open,
949 .release = device_close,
950 .read = device_read,
951 .write = device_write,
952 .poll = device_poll,
953 .owner = THIS_MODULE,
954 .llseek = noop_llseek,
955};
956
957static const struct file_operations ctl_device_fops = {
958 .open = ctl_device_open,
959 .release = ctl_device_close,
960 .read = device_read,
961 .write = device_write,
962 .owner = THIS_MODULE,
963 .llseek = noop_llseek,
964};
965
966static struct miscdevice ctl_device = {
967 .name = "dlm-control",
968 .fops = &ctl_device_fops,
969 .minor = MISC_DYNAMIC_MINOR,
970};
971
972static const struct file_operations monitor_device_fops = {
973 .open = monitor_device_open,
974 .release = monitor_device_close,
975 .owner = THIS_MODULE,
976 .llseek = noop_llseek,
977};
978
979static struct miscdevice monitor_device = {
980 .name = "dlm-monitor",
981 .fops = &monitor_device_fops,
982 .minor = MISC_DYNAMIC_MINOR,
983};
984
985int __init dlm_user_init(void)
986{
987 int error;
988
989 atomic_set(&dlm_monitor_opened, 0);
990
991 error = misc_register(&ctl_device);
992 if (error) {
993 log_print("misc_register failed for control device");
994 goto out;
995 }
996
997 error = misc_register(&monitor_device);
998 if (error) {
999 log_print("misc_register failed for monitor device");
1000 misc_deregister(&ctl_device);
1001 }
1002 out:
1003 return error;
1004}
1005
1006void dlm_user_exit(void)
1007{
1008 misc_deregister(&ctl_device);
1009 misc_deregister(&monitor_device);
1010}
1011
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006-2010 Red Hat, Inc. All rights reserved.
4 */
5
6#include <linux/miscdevice.h>
7#include <linux/init.h>
8#include <linux/wait.h>
9#include <linux/file.h>
10#include <linux/fs.h>
11#include <linux/poll.h>
12#include <linux/signal.h>
13#include <linux/spinlock.h>
14#include <linux/dlm.h>
15#include <linux/dlm_device.h>
16#include <linux/slab.h>
17#include <linux/sched/signal.h>
18
19#include <trace/events/dlm.h>
20
21#include "dlm_internal.h"
22#include "lockspace.h"
23#include "lock.h"
24#include "user.h"
25#include "ast.h"
26#include "config.h"
27#include "memory.h"
28
29static const char name_prefix[] = "dlm";
30static const struct file_operations device_fops;
31static atomic_t dlm_monitor_opened;
32static int dlm_monitor_unused = 1;
33
34#ifdef CONFIG_COMPAT
35
36struct dlm_lock_params32 {
37 __u8 mode;
38 __u8 namelen;
39 __u16 unused;
40 __u32 flags;
41 __u32 lkid;
42 __u32 parent;
43 __u64 xid;
44 __u64 timeout;
45 __u32 castparam;
46 __u32 castaddr;
47 __u32 bastparam;
48 __u32 bastaddr;
49 __u32 lksb;
50 char lvb[DLM_USER_LVB_LEN];
51 char name[];
52};
53
54struct dlm_write_request32 {
55 __u32 version[3];
56 __u8 cmd;
57 __u8 is64bit;
58 __u8 unused[2];
59
60 union {
61 struct dlm_lock_params32 lock;
62 struct dlm_lspace_params lspace;
63 struct dlm_purge_params purge;
64 } i;
65};
66
67struct dlm_lksb32 {
68 __u32 sb_status;
69 __u32 sb_lkid;
70 __u8 sb_flags;
71 __u32 sb_lvbptr;
72};
73
74struct dlm_lock_result32 {
75 __u32 version[3];
76 __u32 length;
77 __u32 user_astaddr;
78 __u32 user_astparam;
79 __u32 user_lksb;
80 struct dlm_lksb32 lksb;
81 __u8 bast_mode;
82 __u8 unused[3];
83 /* Offsets may be zero if no data is present */
84 __u32 lvb_offset;
85};
86
87static void compat_input(struct dlm_write_request *kb,
88 struct dlm_write_request32 *kb32,
89 int namelen)
90{
91 kb->version[0] = kb32->version[0];
92 kb->version[1] = kb32->version[1];
93 kb->version[2] = kb32->version[2];
94
95 kb->cmd = kb32->cmd;
96 kb->is64bit = kb32->is64bit;
97 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
98 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
99 kb->i.lspace.flags = kb32->i.lspace.flags;
100 kb->i.lspace.minor = kb32->i.lspace.minor;
101 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
102 } else if (kb->cmd == DLM_USER_PURGE) {
103 kb->i.purge.nodeid = kb32->i.purge.nodeid;
104 kb->i.purge.pid = kb32->i.purge.pid;
105 } else {
106 kb->i.lock.mode = kb32->i.lock.mode;
107 kb->i.lock.namelen = kb32->i.lock.namelen;
108 kb->i.lock.flags = kb32->i.lock.flags;
109 kb->i.lock.lkid = kb32->i.lock.lkid;
110 kb->i.lock.parent = kb32->i.lock.parent;
111 kb->i.lock.xid = kb32->i.lock.xid;
112 kb->i.lock.timeout = kb32->i.lock.timeout;
113 kb->i.lock.castparam = (__user void *)(long)kb32->i.lock.castparam;
114 kb->i.lock.castaddr = (__user void *)(long)kb32->i.lock.castaddr;
115 kb->i.lock.bastparam = (__user void *)(long)kb32->i.lock.bastparam;
116 kb->i.lock.bastaddr = (__user void *)(long)kb32->i.lock.bastaddr;
117 kb->i.lock.lksb = (__user void *)(long)kb32->i.lock.lksb;
118 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
119 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
120 }
121}
122
123static void compat_output(struct dlm_lock_result *res,
124 struct dlm_lock_result32 *res32)
125{
126 memset(res32, 0, sizeof(*res32));
127
128 res32->version[0] = res->version[0];
129 res32->version[1] = res->version[1];
130 res32->version[2] = res->version[2];
131
132 res32->user_astaddr = (__u32)(__force long)res->user_astaddr;
133 res32->user_astparam = (__u32)(__force long)res->user_astparam;
134 res32->user_lksb = (__u32)(__force long)res->user_lksb;
135 res32->bast_mode = res->bast_mode;
136
137 res32->lvb_offset = res->lvb_offset;
138 res32->length = res->length;
139
140 res32->lksb.sb_status = res->lksb.sb_status;
141 res32->lksb.sb_flags = res->lksb.sb_flags;
142 res32->lksb.sb_lkid = res->lksb.sb_lkid;
143 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
144}
145#endif
146
147/* should held proc->asts_spin lock */
148void dlm_purge_lkb_callbacks(struct dlm_lkb *lkb)
149{
150 struct dlm_callback *cb, *safe;
151
152 list_for_each_entry_safe(cb, safe, &lkb->lkb_callbacks, list) {
153 list_del(&cb->list);
154 kref_put(&cb->ref, dlm_release_callback);
155 }
156
157 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
158
159 /* invalidate */
160 dlm_callback_set_last_ptr(&lkb->lkb_last_cast, NULL);
161 dlm_callback_set_last_ptr(&lkb->lkb_last_cb, NULL);
162 lkb->lkb_last_bast_mode = -1;
163}
164
165/* Figure out if this lock is at the end of its life and no longer
166 available for the application to use. The lkb still exists until
167 the final ast is read. A lock becomes EOL in three situations:
168 1. a noqueue request fails with EAGAIN
169 2. an unlock completes with EUNLOCK
170 3. a cancel of a waiting request completes with ECANCEL/EDEADLK
171 An EOL lock needs to be removed from the process's list of locks.
172 And we can't allow any new operation on an EOL lock. This is
173 not related to the lifetime of the lkb struct which is managed
174 entirely by refcount. */
175
176static int lkb_is_endoflife(int mode, int status)
177{
178 switch (status) {
179 case -DLM_EUNLOCK:
180 return 1;
181 case -DLM_ECANCEL:
182 case -ETIMEDOUT:
183 case -EDEADLK:
184 case -EAGAIN:
185 if (mode == DLM_LOCK_IV)
186 return 1;
187 break;
188 }
189 return 0;
190}
191
192/* we could possibly check if the cancel of an orphan has resulted in the lkb
193 being removed and then remove that lkb from the orphans list and free it */
194
195void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
196 int status, uint32_t sbflags)
197{
198 struct dlm_ls *ls;
199 struct dlm_user_args *ua;
200 struct dlm_user_proc *proc;
201 int rv;
202
203 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) ||
204 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags))
205 return;
206
207 ls = lkb->lkb_resource->res_ls;
208 spin_lock(&ls->ls_clear_proc_locks);
209
210 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
211 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
212 lkb->ua so we can't try to use it. This second check is necessary
213 for cases where a completion ast is received for an operation that
214 began before clear_proc_locks did its cancel/unlock. */
215
216 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) ||
217 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags))
218 goto out;
219
220 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
221 ua = lkb->lkb_ua;
222 proc = ua->proc;
223
224 if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
225 goto out;
226
227 if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
228 set_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags);
229
230 spin_lock(&proc->asts_spin);
231
232 rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
233 switch (rv) {
234 case DLM_ENQUEUE_CALLBACK_FAILURE:
235 spin_unlock(&proc->asts_spin);
236 WARN_ON_ONCE(1);
237 goto out;
238 case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
239 kref_get(&lkb->lkb_ref);
240 list_add_tail(&lkb->lkb_cb_list, &proc->asts);
241 wake_up_interruptible(&proc->wait);
242 break;
243 case DLM_ENQUEUE_CALLBACK_SUCCESS:
244 break;
245 default:
246 WARN_ON_ONCE(1);
247 break;
248 }
249 spin_unlock(&proc->asts_spin);
250
251 if (test_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags)) {
252 /* N.B. spin_lock locks_spin, not asts_spin */
253 spin_lock(&proc->locks_spin);
254 if (!list_empty(&lkb->lkb_ownqueue)) {
255 list_del_init(&lkb->lkb_ownqueue);
256 dlm_put_lkb(lkb);
257 }
258 spin_unlock(&proc->locks_spin);
259 }
260 out:
261 spin_unlock(&ls->ls_clear_proc_locks);
262}
263
264static int device_user_lock(struct dlm_user_proc *proc,
265 struct dlm_lock_params *params)
266{
267 struct dlm_ls *ls;
268 struct dlm_user_args *ua;
269 uint32_t lkid;
270 int error = -ENOMEM;
271
272 ls = dlm_find_lockspace_local(proc->lockspace);
273 if (!ls)
274 return -ENOENT;
275
276 if (!params->castaddr || !params->lksb) {
277 error = -EINVAL;
278 goto out;
279 }
280
281 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
282 if (!ua)
283 goto out;
284 ua->proc = proc;
285 ua->user_lksb = params->lksb;
286 ua->castparam = params->castparam;
287 ua->castaddr = params->castaddr;
288 ua->bastparam = params->bastparam;
289 ua->bastaddr = params->bastaddr;
290 ua->xid = params->xid;
291
292 if (params->flags & DLM_LKF_CONVERT) {
293 error = dlm_user_convert(ls, ua,
294 params->mode, params->flags,
295 params->lkid, params->lvb);
296 } else if (params->flags & DLM_LKF_ORPHAN) {
297 error = dlm_user_adopt_orphan(ls, ua,
298 params->mode, params->flags,
299 params->name, params->namelen,
300 &lkid);
301 if (!error)
302 error = lkid;
303 } else {
304 error = dlm_user_request(ls, ua,
305 params->mode, params->flags,
306 params->name, params->namelen);
307 if (!error)
308 error = ua->lksb.sb_lkid;
309 }
310 out:
311 dlm_put_lockspace(ls);
312 return error;
313}
314
315static int device_user_unlock(struct dlm_user_proc *proc,
316 struct dlm_lock_params *params)
317{
318 struct dlm_ls *ls;
319 struct dlm_user_args *ua;
320 int error = -ENOMEM;
321
322 ls = dlm_find_lockspace_local(proc->lockspace);
323 if (!ls)
324 return -ENOENT;
325
326 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
327 if (!ua)
328 goto out;
329 ua->proc = proc;
330 ua->user_lksb = params->lksb;
331 ua->castparam = params->castparam;
332 ua->castaddr = params->castaddr;
333
334 if (params->flags & DLM_LKF_CANCEL)
335 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
336 else
337 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
338 params->lvb);
339 out:
340 dlm_put_lockspace(ls);
341 return error;
342}
343
344static int device_user_deadlock(struct dlm_user_proc *proc,
345 struct dlm_lock_params *params)
346{
347 struct dlm_ls *ls;
348 int error;
349
350 ls = dlm_find_lockspace_local(proc->lockspace);
351 if (!ls)
352 return -ENOENT;
353
354 error = dlm_user_deadlock(ls, params->flags, params->lkid);
355
356 dlm_put_lockspace(ls);
357 return error;
358}
359
360static int dlm_device_register(struct dlm_ls *ls, char *name)
361{
362 int error, len;
363
364 /* The device is already registered. This happens when the
365 lockspace is created multiple times from userspace. */
366 if (ls->ls_device.name)
367 return 0;
368
369 error = -ENOMEM;
370 len = strlen(name) + strlen(name_prefix) + 2;
371 ls->ls_device.name = kzalloc(len, GFP_NOFS);
372 if (!ls->ls_device.name)
373 goto fail;
374
375 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
376 name);
377 ls->ls_device.fops = &device_fops;
378 ls->ls_device.minor = MISC_DYNAMIC_MINOR;
379
380 error = misc_register(&ls->ls_device);
381 if (error) {
382 kfree(ls->ls_device.name);
383 /* this has to be set to NULL
384 * to avoid a double-free in dlm_device_deregister
385 */
386 ls->ls_device.name = NULL;
387 }
388fail:
389 return error;
390}
391
392int dlm_device_deregister(struct dlm_ls *ls)
393{
394 /* The device is not registered. This happens when the lockspace
395 was never used from userspace, or when device_create_lockspace()
396 calls dlm_release_lockspace() after the register fails. */
397 if (!ls->ls_device.name)
398 return 0;
399
400 misc_deregister(&ls->ls_device);
401 kfree(ls->ls_device.name);
402 return 0;
403}
404
405static int device_user_purge(struct dlm_user_proc *proc,
406 struct dlm_purge_params *params)
407{
408 struct dlm_ls *ls;
409 int error;
410
411 ls = dlm_find_lockspace_local(proc->lockspace);
412 if (!ls)
413 return -ENOENT;
414
415 error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
416
417 dlm_put_lockspace(ls);
418 return error;
419}
420
421static int device_create_lockspace(struct dlm_lspace_params *params)
422{
423 dlm_lockspace_t *lockspace;
424 struct dlm_ls *ls;
425 int error;
426
427 if (!capable(CAP_SYS_ADMIN))
428 return -EPERM;
429
430 error = dlm_new_user_lockspace(params->name, dlm_config.ci_cluster_name,
431 params->flags, DLM_USER_LVB_LEN, NULL,
432 NULL, NULL, &lockspace);
433 if (error)
434 return error;
435
436 ls = dlm_find_lockspace_local(lockspace);
437 if (!ls)
438 return -ENOENT;
439
440 error = dlm_device_register(ls, params->name);
441 dlm_put_lockspace(ls);
442
443 if (error)
444 dlm_release_lockspace(lockspace, 0);
445 else
446 error = ls->ls_device.minor;
447
448 return error;
449}
450
451static int device_remove_lockspace(struct dlm_lspace_params *params)
452{
453 dlm_lockspace_t *lockspace;
454 struct dlm_ls *ls;
455 int error, force = 0;
456
457 if (!capable(CAP_SYS_ADMIN))
458 return -EPERM;
459
460 ls = dlm_find_lockspace_device(params->minor);
461 if (!ls)
462 return -ENOENT;
463
464 if (params->flags & DLM_USER_LSFLG_FORCEFREE)
465 force = 2;
466
467 lockspace = ls->ls_local_handle;
468 dlm_put_lockspace(ls);
469
470 /* The final dlm_release_lockspace waits for references to go to
471 zero, so all processes will need to close their device for the
472 ls before the release will proceed. release also calls the
473 device_deregister above. Converting a positive return value
474 from release to zero means that userspace won't know when its
475 release was the final one, but it shouldn't need to know. */
476
477 error = dlm_release_lockspace(lockspace, force);
478 if (error > 0)
479 error = 0;
480 return error;
481}
482
483/* Check the user's version matches ours */
484static int check_version(struct dlm_write_request *req)
485{
486 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
487 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
488 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
489
490 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
491 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
492 current->comm,
493 task_pid_nr(current),
494 req->version[0],
495 req->version[1],
496 req->version[2],
497 DLM_DEVICE_VERSION_MAJOR,
498 DLM_DEVICE_VERSION_MINOR,
499 DLM_DEVICE_VERSION_PATCH);
500 return -EINVAL;
501 }
502 return 0;
503}
504
505/*
506 * device_write
507 *
508 * device_user_lock
509 * dlm_user_request -> request_lock
510 * dlm_user_convert -> convert_lock
511 *
512 * device_user_unlock
513 * dlm_user_unlock -> unlock_lock
514 * dlm_user_cancel -> cancel_lock
515 *
516 * device_create_lockspace
517 * dlm_new_lockspace
518 *
519 * device_remove_lockspace
520 * dlm_release_lockspace
521 */
522
523/* a write to a lockspace device is a lock or unlock request, a write
524 to the control device is to create/remove a lockspace */
525
526static ssize_t device_write(struct file *file, const char __user *buf,
527 size_t count, loff_t *ppos)
528{
529 struct dlm_user_proc *proc = file->private_data;
530 struct dlm_write_request *kbuf;
531 int error;
532
533#ifdef CONFIG_COMPAT
534 if (count < sizeof(struct dlm_write_request32))
535#else
536 if (count < sizeof(struct dlm_write_request))
537#endif
538 return -EINVAL;
539
540 /*
541 * can't compare against COMPAT/dlm_write_request32 because
542 * we don't yet know if is64bit is zero
543 */
544 if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
545 return -EINVAL;
546
547 kbuf = memdup_user_nul(buf, count);
548 if (IS_ERR(kbuf))
549 return PTR_ERR(kbuf);
550
551 if (check_version(kbuf)) {
552 error = -EBADE;
553 goto out_free;
554 }
555
556#ifdef CONFIG_COMPAT
557 if (!kbuf->is64bit) {
558 struct dlm_write_request32 *k32buf;
559 int namelen = 0;
560
561 if (count > sizeof(struct dlm_write_request32))
562 namelen = count - sizeof(struct dlm_write_request32);
563
564 k32buf = (struct dlm_write_request32 *)kbuf;
565
566 /* add 1 after namelen so that the name string is terminated */
567 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
568 GFP_NOFS);
569 if (!kbuf) {
570 kfree(k32buf);
571 return -ENOMEM;
572 }
573
574 if (proc)
575 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
576
577 compat_input(kbuf, k32buf, namelen);
578 kfree(k32buf);
579 }
580#endif
581
582 /* do we really need this? can a write happen after a close? */
583 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
584 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
585 error = -EINVAL;
586 goto out_free;
587 }
588
589 error = -EINVAL;
590
591 switch (kbuf->cmd)
592 {
593 case DLM_USER_LOCK:
594 if (!proc) {
595 log_print("no locking on control device");
596 goto out_free;
597 }
598 error = device_user_lock(proc, &kbuf->i.lock);
599 break;
600
601 case DLM_USER_UNLOCK:
602 if (!proc) {
603 log_print("no locking on control device");
604 goto out_free;
605 }
606 error = device_user_unlock(proc, &kbuf->i.lock);
607 break;
608
609 case DLM_USER_DEADLOCK:
610 if (!proc) {
611 log_print("no locking on control device");
612 goto out_free;
613 }
614 error = device_user_deadlock(proc, &kbuf->i.lock);
615 break;
616
617 case DLM_USER_CREATE_LOCKSPACE:
618 if (proc) {
619 log_print("create/remove only on control device");
620 goto out_free;
621 }
622 error = device_create_lockspace(&kbuf->i.lspace);
623 break;
624
625 case DLM_USER_REMOVE_LOCKSPACE:
626 if (proc) {
627 log_print("create/remove only on control device");
628 goto out_free;
629 }
630 error = device_remove_lockspace(&kbuf->i.lspace);
631 break;
632
633 case DLM_USER_PURGE:
634 if (!proc) {
635 log_print("no locking on control device");
636 goto out_free;
637 }
638 error = device_user_purge(proc, &kbuf->i.purge);
639 break;
640
641 default:
642 log_print("Unknown command passed to DLM device : %d\n",
643 kbuf->cmd);
644 }
645
646 out_free:
647 kfree(kbuf);
648 return error;
649}
650
651/* Every process that opens the lockspace device has its own "proc" structure
652 hanging off the open file that's used to keep track of locks owned by the
653 process and asts that need to be delivered to the process. */
654
655static int device_open(struct inode *inode, struct file *file)
656{
657 struct dlm_user_proc *proc;
658 struct dlm_ls *ls;
659
660 ls = dlm_find_lockspace_device(iminor(inode));
661 if (!ls)
662 return -ENOENT;
663
664 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
665 if (!proc) {
666 dlm_put_lockspace(ls);
667 return -ENOMEM;
668 }
669
670 proc->lockspace = ls->ls_local_handle;
671 INIT_LIST_HEAD(&proc->asts);
672 INIT_LIST_HEAD(&proc->locks);
673 INIT_LIST_HEAD(&proc->unlocking);
674 spin_lock_init(&proc->asts_spin);
675 spin_lock_init(&proc->locks_spin);
676 init_waitqueue_head(&proc->wait);
677 file->private_data = proc;
678
679 return 0;
680}
681
682static int device_close(struct inode *inode, struct file *file)
683{
684 struct dlm_user_proc *proc = file->private_data;
685 struct dlm_ls *ls;
686
687 ls = dlm_find_lockspace_local(proc->lockspace);
688 if (!ls)
689 return -ENOENT;
690
691 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
692
693 dlm_clear_proc_locks(ls, proc);
694
695 /* at this point no more lkb's should exist for this lockspace,
696 so there's no chance of dlm_user_add_ast() being called and
697 looking for lkb->ua->proc */
698
699 kfree(proc);
700 file->private_data = NULL;
701
702 dlm_put_lockspace(ls);
703 dlm_put_lockspace(ls); /* for the find in device_open() */
704
705 /* FIXME: AUTOFREE: if this ls is no longer used do
706 device_remove_lockspace() */
707
708 return 0;
709}
710
711static int copy_result_to_user(struct dlm_user_args *ua, int compat,
712 uint32_t flags, int mode, int copy_lvb,
713 char __user *buf, size_t count)
714{
715#ifdef CONFIG_COMPAT
716 struct dlm_lock_result32 result32;
717#endif
718 struct dlm_lock_result result;
719 void *resultptr;
720 int error=0;
721 int len;
722 int struct_len;
723
724 memset(&result, 0, sizeof(struct dlm_lock_result));
725 result.version[0] = DLM_DEVICE_VERSION_MAJOR;
726 result.version[1] = DLM_DEVICE_VERSION_MINOR;
727 result.version[2] = DLM_DEVICE_VERSION_PATCH;
728 memcpy(&result.lksb, &ua->lksb, offsetof(struct dlm_lksb, sb_lvbptr));
729 result.user_lksb = ua->user_lksb;
730
731 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
732 in a conversion unless the conversion is successful. See code
733 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though,
734 notes that a new blocking AST address and parameter are set even if
735 the conversion fails, so maybe we should just do that. */
736
737 if (flags & DLM_CB_BAST) {
738 result.user_astaddr = ua->bastaddr;
739 result.user_astparam = ua->bastparam;
740 result.bast_mode = mode;
741 } else {
742 result.user_astaddr = ua->castaddr;
743 result.user_astparam = ua->castparam;
744 }
745
746#ifdef CONFIG_COMPAT
747 if (compat)
748 len = sizeof(struct dlm_lock_result32);
749 else
750#endif
751 len = sizeof(struct dlm_lock_result);
752 struct_len = len;
753
754 /* copy lvb to userspace if there is one, it's been updated, and
755 the user buffer has space for it */
756
757 if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
758 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
759 DLM_USER_LVB_LEN)) {
760 error = -EFAULT;
761 goto out;
762 }
763
764 result.lvb_offset = len;
765 len += DLM_USER_LVB_LEN;
766 }
767
768 result.length = len;
769 resultptr = &result;
770#ifdef CONFIG_COMPAT
771 if (compat) {
772 compat_output(&result, &result32);
773 resultptr = &result32;
774 }
775#endif
776
777 if (copy_to_user(buf, resultptr, struct_len))
778 error = -EFAULT;
779 else
780 error = len;
781 out:
782 return error;
783}
784
785static int copy_version_to_user(char __user *buf, size_t count)
786{
787 struct dlm_device_version ver;
788
789 memset(&ver, 0, sizeof(struct dlm_device_version));
790 ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
791 ver.version[1] = DLM_DEVICE_VERSION_MINOR;
792 ver.version[2] = DLM_DEVICE_VERSION_PATCH;
793
794 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
795 return -EFAULT;
796 return sizeof(struct dlm_device_version);
797}
798
799/* a read returns a single ast described in a struct dlm_lock_result */
800
801static ssize_t device_read(struct file *file, char __user *buf, size_t count,
802 loff_t *ppos)
803{
804 struct dlm_user_proc *proc = file->private_data;
805 struct dlm_lkb *lkb;
806 DECLARE_WAITQUEUE(wait, current);
807 struct dlm_callback *cb;
808 int rv, ret;
809
810 if (count == sizeof(struct dlm_device_version)) {
811 rv = copy_version_to_user(buf, count);
812 return rv;
813 }
814
815 if (!proc) {
816 log_print("non-version read from control device %zu", count);
817 return -EINVAL;
818 }
819
820#ifdef CONFIG_COMPAT
821 if (count < sizeof(struct dlm_lock_result32))
822#else
823 if (count < sizeof(struct dlm_lock_result))
824#endif
825 return -EINVAL;
826
827 try_another:
828
829 /* do we really need this? can a read happen after a close? */
830 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
831 return -EINVAL;
832
833 spin_lock(&proc->asts_spin);
834 if (list_empty(&proc->asts)) {
835 if (file->f_flags & O_NONBLOCK) {
836 spin_unlock(&proc->asts_spin);
837 return -EAGAIN;
838 }
839
840 add_wait_queue(&proc->wait, &wait);
841
842 repeat:
843 set_current_state(TASK_INTERRUPTIBLE);
844 if (list_empty(&proc->asts) && !signal_pending(current)) {
845 spin_unlock(&proc->asts_spin);
846 schedule();
847 spin_lock(&proc->asts_spin);
848 goto repeat;
849 }
850 set_current_state(TASK_RUNNING);
851 remove_wait_queue(&proc->wait, &wait);
852
853 if (signal_pending(current)) {
854 spin_unlock(&proc->asts_spin);
855 return -ERESTARTSYS;
856 }
857 }
858
859 /* if we empty lkb_callbacks, we don't want to unlock the spinlock
860 without removing lkb_cb_list; so empty lkb_cb_list is always
861 consistent with empty lkb_callbacks */
862
863 lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list);
864
865 rv = dlm_dequeue_lkb_callback(lkb, &cb);
866 switch (rv) {
867 case DLM_DEQUEUE_CALLBACK_EMPTY:
868 /* this shouldn't happen; lkb should have been removed from
869 * list when last item was dequeued
870 */
871 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
872 list_del_init(&lkb->lkb_cb_list);
873 spin_unlock(&proc->asts_spin);
874 /* removes ref for proc->asts, may cause lkb to be freed */
875 dlm_put_lkb(lkb);
876 WARN_ON_ONCE(1);
877 goto try_another;
878 case DLM_DEQUEUE_CALLBACK_LAST:
879 list_del_init(&lkb->lkb_cb_list);
880 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
881 break;
882 case DLM_DEQUEUE_CALLBACK_SUCCESS:
883 break;
884 default:
885 WARN_ON_ONCE(1);
886 break;
887 }
888 spin_unlock(&proc->asts_spin);
889
890 if (cb->flags & DLM_CB_BAST) {
891 trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode);
892 } else if (cb->flags & DLM_CB_CAST) {
893 lkb->lkb_lksb->sb_status = cb->sb_status;
894 lkb->lkb_lksb->sb_flags = cb->sb_flags;
895 trace_dlm_ast(lkb->lkb_resource->res_ls, lkb);
896 }
897
898 ret = copy_result_to_user(lkb->lkb_ua,
899 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
900 cb->flags, cb->mode, cb->copy_lvb, buf, count);
901
902 kref_put(&cb->ref, dlm_release_callback);
903
904 /* removes ref for proc->asts, may cause lkb to be freed */
905 if (rv == DLM_DEQUEUE_CALLBACK_LAST)
906 dlm_put_lkb(lkb);
907
908 return ret;
909}
910
911static __poll_t device_poll(struct file *file, poll_table *wait)
912{
913 struct dlm_user_proc *proc = file->private_data;
914
915 poll_wait(file, &proc->wait, wait);
916
917 spin_lock(&proc->asts_spin);
918 if (!list_empty(&proc->asts)) {
919 spin_unlock(&proc->asts_spin);
920 return EPOLLIN | EPOLLRDNORM;
921 }
922 spin_unlock(&proc->asts_spin);
923 return 0;
924}
925
926int dlm_user_daemon_available(void)
927{
928 /* dlm_controld hasn't started (or, has started, but not
929 properly populated configfs) */
930
931 if (!dlm_our_nodeid())
932 return 0;
933
934 /* This is to deal with versions of dlm_controld that don't
935 know about the monitor device. We assume that if the
936 dlm_controld was started (above), but the monitor device
937 was never opened, that it's an old version. dlm_controld
938 should open the monitor device before populating configfs. */
939
940 if (dlm_monitor_unused)
941 return 1;
942
943 return atomic_read(&dlm_monitor_opened) ? 1 : 0;
944}
945
946static int ctl_device_open(struct inode *inode, struct file *file)
947{
948 file->private_data = NULL;
949 return 0;
950}
951
952static int ctl_device_close(struct inode *inode, struct file *file)
953{
954 return 0;
955}
956
957static int monitor_device_open(struct inode *inode, struct file *file)
958{
959 atomic_inc(&dlm_monitor_opened);
960 dlm_monitor_unused = 0;
961 return 0;
962}
963
964static int monitor_device_close(struct inode *inode, struct file *file)
965{
966 if (atomic_dec_and_test(&dlm_monitor_opened))
967 dlm_stop_lockspaces();
968 return 0;
969}
970
971static const struct file_operations device_fops = {
972 .open = device_open,
973 .release = device_close,
974 .read = device_read,
975 .write = device_write,
976 .poll = device_poll,
977 .owner = THIS_MODULE,
978 .llseek = noop_llseek,
979};
980
981static const struct file_operations ctl_device_fops = {
982 .open = ctl_device_open,
983 .release = ctl_device_close,
984 .read = device_read,
985 .write = device_write,
986 .owner = THIS_MODULE,
987 .llseek = noop_llseek,
988};
989
990static struct miscdevice ctl_device = {
991 .name = "dlm-control",
992 .fops = &ctl_device_fops,
993 .minor = MISC_DYNAMIC_MINOR,
994};
995
996static const struct file_operations monitor_device_fops = {
997 .open = monitor_device_open,
998 .release = monitor_device_close,
999 .owner = THIS_MODULE,
1000 .llseek = noop_llseek,
1001};
1002
1003static struct miscdevice monitor_device = {
1004 .name = "dlm-monitor",
1005 .fops = &monitor_device_fops,
1006 .minor = MISC_DYNAMIC_MINOR,
1007};
1008
1009int __init dlm_user_init(void)
1010{
1011 int error;
1012
1013 atomic_set(&dlm_monitor_opened, 0);
1014
1015 error = misc_register(&ctl_device);
1016 if (error) {
1017 log_print("misc_register failed for control device");
1018 goto out;
1019 }
1020
1021 error = misc_register(&monitor_device);
1022 if (error) {
1023 log_print("misc_register failed for monitor device");
1024 misc_deregister(&ctl_device);
1025 }
1026 out:
1027 return error;
1028}
1029
1030void dlm_user_exit(void)
1031{
1032 misc_deregister(&ctl_device);
1033 misc_deregister(&monitor_device);
1034}
1035