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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
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