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