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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 "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
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 "dlm_internal.h"
20#include "lockspace.h"
21#include "lock.h"
22#include "lvb_table.h"
23#include "user.h"
24#include "ast.h"
25#include "config.h"
26
27static const char name_prefix[] = "dlm";
28static const struct file_operations device_fops;
29static atomic_t dlm_monitor_opened;
30static int dlm_monitor_unused = 1;
31
32#ifdef CONFIG_COMPAT
33
34struct dlm_lock_params32 {
35 __u8 mode;
36 __u8 namelen;
37 __u16 unused;
38 __u32 flags;
39 __u32 lkid;
40 __u32 parent;
41 __u64 xid;
42 __u64 timeout;
43 __u32 castparam;
44 __u32 castaddr;
45 __u32 bastparam;
46 __u32 bastaddr;
47 __u32 lksb;
48 char lvb[DLM_USER_LVB_LEN];
49 char name[];
50};
51
52struct dlm_write_request32 {
53 __u32 version[3];
54 __u8 cmd;
55 __u8 is64bit;
56 __u8 unused[2];
57
58 union {
59 struct dlm_lock_params32 lock;
60 struct dlm_lspace_params lspace;
61 struct dlm_purge_params purge;
62 } i;
63};
64
65struct dlm_lksb32 {
66 __u32 sb_status;
67 __u32 sb_lkid;
68 __u8 sb_flags;
69 __u32 sb_lvbptr;
70};
71
72struct dlm_lock_result32 {
73 __u32 version[3];
74 __u32 length;
75 __u32 user_astaddr;
76 __u32 user_astparam;
77 __u32 user_lksb;
78 struct dlm_lksb32 lksb;
79 __u8 bast_mode;
80 __u8 unused[3];
81 /* Offsets may be zero if no data is present */
82 __u32 lvb_offset;
83};
84
85static void compat_input(struct dlm_write_request *kb,
86 struct dlm_write_request32 *kb32,
87 int namelen)
88{
89 kb->version[0] = kb32->version[0];
90 kb->version[1] = kb32->version[1];
91 kb->version[2] = kb32->version[2];
92
93 kb->cmd = kb32->cmd;
94 kb->is64bit = kb32->is64bit;
95 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
96 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
97 kb->i.lspace.flags = kb32->i.lspace.flags;
98 kb->i.lspace.minor = kb32->i.lspace.minor;
99 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
100 } else if (kb->cmd == DLM_USER_PURGE) {
101 kb->i.purge.nodeid = kb32->i.purge.nodeid;
102 kb->i.purge.pid = kb32->i.purge.pid;
103 } else {
104 kb->i.lock.mode = kb32->i.lock.mode;
105 kb->i.lock.namelen = kb32->i.lock.namelen;
106 kb->i.lock.flags = kb32->i.lock.flags;
107 kb->i.lock.lkid = kb32->i.lock.lkid;
108 kb->i.lock.parent = kb32->i.lock.parent;
109 kb->i.lock.xid = kb32->i.lock.xid;
110 kb->i.lock.timeout = kb32->i.lock.timeout;
111 kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
112 kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
113 kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
114 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
115 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
116 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
117 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
118 }
119}
120
121static void compat_output(struct dlm_lock_result *res,
122 struct dlm_lock_result32 *res32)
123{
124 memset(res32, 0, sizeof(*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 uint32_t lkid;
242 int error = -ENOMEM;
243
244 ls = dlm_find_lockspace_local(proc->lockspace);
245 if (!ls)
246 return -ENOENT;
247
248 if (!params->castaddr || !params->lksb) {
249 error = -EINVAL;
250 goto out;
251 }
252
253 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
254 if (!ua)
255 goto out;
256 ua->proc = proc;
257 ua->user_lksb = params->lksb;
258 ua->castparam = params->castparam;
259 ua->castaddr = params->castaddr;
260 ua->bastparam = params->bastparam;
261 ua->bastaddr = params->bastaddr;
262 ua->xid = params->xid;
263
264 if (params->flags & DLM_LKF_CONVERT) {
265 error = dlm_user_convert(ls, ua,
266 params->mode, params->flags,
267 params->lkid, params->lvb,
268 (unsigned long) params->timeout);
269 } else if (params->flags & DLM_LKF_ORPHAN) {
270 error = dlm_user_adopt_orphan(ls, ua,
271 params->mode, params->flags,
272 params->name, params->namelen,
273 (unsigned long) params->timeout,
274 &lkid);
275 if (!error)
276 error = lkid;
277 } else {
278 error = dlm_user_request(ls, ua,
279 params->mode, params->flags,
280 params->name, params->namelen,
281 (unsigned long) params->timeout);
282 if (!error)
283 error = ua->lksb.sb_lkid;
284 }
285 out:
286 dlm_put_lockspace(ls);
287 return error;
288}
289
290static int device_user_unlock(struct dlm_user_proc *proc,
291 struct dlm_lock_params *params)
292{
293 struct dlm_ls *ls;
294 struct dlm_user_args *ua;
295 int error = -ENOMEM;
296
297 ls = dlm_find_lockspace_local(proc->lockspace);
298 if (!ls)
299 return -ENOENT;
300
301 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
302 if (!ua)
303 goto out;
304 ua->proc = proc;
305 ua->user_lksb = params->lksb;
306 ua->castparam = params->castparam;
307 ua->castaddr = params->castaddr;
308
309 if (params->flags & DLM_LKF_CANCEL)
310 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
311 else
312 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
313 params->lvb);
314 out:
315 dlm_put_lockspace(ls);
316 return error;
317}
318
319static int device_user_deadlock(struct dlm_user_proc *proc,
320 struct dlm_lock_params *params)
321{
322 struct dlm_ls *ls;
323 int error;
324
325 ls = dlm_find_lockspace_local(proc->lockspace);
326 if (!ls)
327 return -ENOENT;
328
329 error = dlm_user_deadlock(ls, params->flags, params->lkid);
330
331 dlm_put_lockspace(ls);
332 return error;
333}
334
335static int dlm_device_register(struct dlm_ls *ls, char *name)
336{
337 int error, len;
338
339 /* The device is already registered. This happens when the
340 lockspace is created multiple times from userspace. */
341 if (ls->ls_device.name)
342 return 0;
343
344 error = -ENOMEM;
345 len = strlen(name) + strlen(name_prefix) + 2;
346 ls->ls_device.name = kzalloc(len, GFP_NOFS);
347 if (!ls->ls_device.name)
348 goto fail;
349
350 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
351 name);
352 ls->ls_device.fops = &device_fops;
353 ls->ls_device.minor = MISC_DYNAMIC_MINOR;
354
355 error = misc_register(&ls->ls_device);
356 if (error) {
357 kfree(ls->ls_device.name);
358 /* this has to be set to NULL
359 * to avoid a double-free in dlm_device_deregister
360 */
361 ls->ls_device.name = NULL;
362 }
363fail:
364 return error;
365}
366
367int dlm_device_deregister(struct dlm_ls *ls)
368{
369 /* The device is not registered. This happens when the lockspace
370 was never used from userspace, or when device_create_lockspace()
371 calls dlm_release_lockspace() after the register fails. */
372 if (!ls->ls_device.name)
373 return 0;
374
375 misc_deregister(&ls->ls_device);
376 kfree(ls->ls_device.name);
377 return 0;
378}
379
380static int device_user_purge(struct dlm_user_proc *proc,
381 struct dlm_purge_params *params)
382{
383 struct dlm_ls *ls;
384 int error;
385
386 ls = dlm_find_lockspace_local(proc->lockspace);
387 if (!ls)
388 return -ENOENT;
389
390 error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
391
392 dlm_put_lockspace(ls);
393 return error;
394}
395
396static int device_create_lockspace(struct dlm_lspace_params *params)
397{
398 dlm_lockspace_t *lockspace;
399 struct dlm_ls *ls;
400 int error;
401
402 if (!capable(CAP_SYS_ADMIN))
403 return -EPERM;
404
405 error = dlm_new_lockspace(params->name, dlm_config.ci_cluster_name, params->flags,
406 DLM_USER_LVB_LEN, NULL, NULL, NULL,
407 &lockspace);
408 if (error)
409 return error;
410
411 ls = dlm_find_lockspace_local(lockspace);
412 if (!ls)
413 return -ENOENT;
414
415 error = dlm_device_register(ls, params->name);
416 dlm_put_lockspace(ls);
417
418 if (error)
419 dlm_release_lockspace(lockspace, 0);
420 else
421 error = ls->ls_device.minor;
422
423 return error;
424}
425
426static int device_remove_lockspace(struct dlm_lspace_params *params)
427{
428 dlm_lockspace_t *lockspace;
429 struct dlm_ls *ls;
430 int error, force = 0;
431
432 if (!capable(CAP_SYS_ADMIN))
433 return -EPERM;
434
435 ls = dlm_find_lockspace_device(params->minor);
436 if (!ls)
437 return -ENOENT;
438
439 if (params->flags & DLM_USER_LSFLG_FORCEFREE)
440 force = 2;
441
442 lockspace = ls->ls_local_handle;
443 dlm_put_lockspace(ls);
444
445 /* The final dlm_release_lockspace waits for references to go to
446 zero, so all processes will need to close their device for the
447 ls before the release will proceed. release also calls the
448 device_deregister above. Converting a positive return value
449 from release to zero means that userspace won't know when its
450 release was the final one, but it shouldn't need to know. */
451
452 error = dlm_release_lockspace(lockspace, force);
453 if (error > 0)
454 error = 0;
455 return error;
456}
457
458/* Check the user's version matches ours */
459static int check_version(struct dlm_write_request *req)
460{
461 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
462 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
463 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
464
465 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
466 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
467 current->comm,
468 task_pid_nr(current),
469 req->version[0],
470 req->version[1],
471 req->version[2],
472 DLM_DEVICE_VERSION_MAJOR,
473 DLM_DEVICE_VERSION_MINOR,
474 DLM_DEVICE_VERSION_PATCH);
475 return -EINVAL;
476 }
477 return 0;
478}
479
480/*
481 * device_write
482 *
483 * device_user_lock
484 * dlm_user_request -> request_lock
485 * dlm_user_convert -> convert_lock
486 *
487 * device_user_unlock
488 * dlm_user_unlock -> unlock_lock
489 * dlm_user_cancel -> cancel_lock
490 *
491 * device_create_lockspace
492 * dlm_new_lockspace
493 *
494 * device_remove_lockspace
495 * dlm_release_lockspace
496 */
497
498/* a write to a lockspace device is a lock or unlock request, a write
499 to the control device is to create/remove a lockspace */
500
501static ssize_t device_write(struct file *file, const char __user *buf,
502 size_t count, loff_t *ppos)
503{
504 struct dlm_user_proc *proc = file->private_data;
505 struct dlm_write_request *kbuf;
506 int error;
507
508#ifdef CONFIG_COMPAT
509 if (count < sizeof(struct dlm_write_request32))
510#else
511 if (count < sizeof(struct dlm_write_request))
512#endif
513 return -EINVAL;
514
515 /*
516 * can't compare against COMPAT/dlm_write_request32 because
517 * we don't yet know if is64bit is zero
518 */
519 if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
520 return -EINVAL;
521
522 kbuf = memdup_user_nul(buf, count);
523 if (IS_ERR(kbuf))
524 return PTR_ERR(kbuf);
525
526 if (check_version(kbuf)) {
527 error = -EBADE;
528 goto out_free;
529 }
530
531#ifdef CONFIG_COMPAT
532 if (!kbuf->is64bit) {
533 struct dlm_write_request32 *k32buf;
534 int namelen = 0;
535
536 if (count > sizeof(struct dlm_write_request32))
537 namelen = count - sizeof(struct dlm_write_request32);
538
539 k32buf = (struct dlm_write_request32 *)kbuf;
540
541 /* add 1 after namelen so that the name string is terminated */
542 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
543 GFP_NOFS);
544 if (!kbuf) {
545 kfree(k32buf);
546 return -ENOMEM;
547 }
548
549 if (proc)
550 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
551
552 compat_input(kbuf, k32buf, namelen);
553 kfree(k32buf);
554 }
555#endif
556
557 /* do we really need this? can a write happen after a close? */
558 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
559 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
560 error = -EINVAL;
561 goto out_free;
562 }
563
564 error = -EINVAL;
565
566 switch (kbuf->cmd)
567 {
568 case DLM_USER_LOCK:
569 if (!proc) {
570 log_print("no locking on control device");
571 goto out_free;
572 }
573 error = device_user_lock(proc, &kbuf->i.lock);
574 break;
575
576 case DLM_USER_UNLOCK:
577 if (!proc) {
578 log_print("no locking on control device");
579 goto out_free;
580 }
581 error = device_user_unlock(proc, &kbuf->i.lock);
582 break;
583
584 case DLM_USER_DEADLOCK:
585 if (!proc) {
586 log_print("no locking on control device");
587 goto out_free;
588 }
589 error = device_user_deadlock(proc, &kbuf->i.lock);
590 break;
591
592 case DLM_USER_CREATE_LOCKSPACE:
593 if (proc) {
594 log_print("create/remove only on control device");
595 goto out_free;
596 }
597 error = device_create_lockspace(&kbuf->i.lspace);
598 break;
599
600 case DLM_USER_REMOVE_LOCKSPACE:
601 if (proc) {
602 log_print("create/remove only on control device");
603 goto out_free;
604 }
605 error = device_remove_lockspace(&kbuf->i.lspace);
606 break;
607
608 case DLM_USER_PURGE:
609 if (!proc) {
610 log_print("no locking on control device");
611 goto out_free;
612 }
613 error = device_user_purge(proc, &kbuf->i.purge);
614 break;
615
616 default:
617 log_print("Unknown command passed to DLM device : %d\n",
618 kbuf->cmd);
619 }
620
621 out_free:
622 kfree(kbuf);
623 return error;
624}
625
626/* Every process that opens the lockspace device has its own "proc" structure
627 hanging off the open file that's used to keep track of locks owned by the
628 process and asts that need to be delivered to the process. */
629
630static int device_open(struct inode *inode, struct file *file)
631{
632 struct dlm_user_proc *proc;
633 struct dlm_ls *ls;
634
635 ls = dlm_find_lockspace_device(iminor(inode));
636 if (!ls)
637 return -ENOENT;
638
639 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
640 if (!proc) {
641 dlm_put_lockspace(ls);
642 return -ENOMEM;
643 }
644
645 proc->lockspace = ls->ls_local_handle;
646 INIT_LIST_HEAD(&proc->asts);
647 INIT_LIST_HEAD(&proc->locks);
648 INIT_LIST_HEAD(&proc->unlocking);
649 spin_lock_init(&proc->asts_spin);
650 spin_lock_init(&proc->locks_spin);
651 init_waitqueue_head(&proc->wait);
652 file->private_data = proc;
653
654 return 0;
655}
656
657static int device_close(struct inode *inode, struct file *file)
658{
659 struct dlm_user_proc *proc = file->private_data;
660 struct dlm_ls *ls;
661
662 ls = dlm_find_lockspace_local(proc->lockspace);
663 if (!ls)
664 return -ENOENT;
665
666 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
667
668 dlm_clear_proc_locks(ls, proc);
669
670 /* at this point no more lkb's should exist for this lockspace,
671 so there's no chance of dlm_user_add_ast() being called and
672 looking for lkb->ua->proc */
673
674 kfree(proc);
675 file->private_data = NULL;
676
677 dlm_put_lockspace(ls);
678 dlm_put_lockspace(ls); /* for the find in device_open() */
679
680 /* FIXME: AUTOFREE: if this ls is no longer used do
681 device_remove_lockspace() */
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, offsetof(struct dlm_lksb, sb_lvbptr));
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 int old_mode, new_mode;
785
786 if (count == sizeof(struct dlm_device_version)) {
787 rv = copy_version_to_user(buf, count);
788 return rv;
789 }
790
791 if (!proc) {
792 log_print("non-version read from control device %zu", count);
793 return -EINVAL;
794 }
795
796#ifdef CONFIG_COMPAT
797 if (count < sizeof(struct dlm_lock_result32))
798#else
799 if (count < sizeof(struct dlm_lock_result))
800#endif
801 return -EINVAL;
802
803 try_another:
804
805 /* do we really need this? can a read happen after a close? */
806 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
807 return -EINVAL;
808
809 spin_lock(&proc->asts_spin);
810 if (list_empty(&proc->asts)) {
811 if (file->f_flags & O_NONBLOCK) {
812 spin_unlock(&proc->asts_spin);
813 return -EAGAIN;
814 }
815
816 add_wait_queue(&proc->wait, &wait);
817
818 repeat:
819 set_current_state(TASK_INTERRUPTIBLE);
820 if (list_empty(&proc->asts) && !signal_pending(current)) {
821 spin_unlock(&proc->asts_spin);
822 schedule();
823 spin_lock(&proc->asts_spin);
824 goto repeat;
825 }
826 set_current_state(TASK_RUNNING);
827 remove_wait_queue(&proc->wait, &wait);
828
829 if (signal_pending(current)) {
830 spin_unlock(&proc->asts_spin);
831 return -ERESTARTSYS;
832 }
833 }
834
835 /* if we empty lkb_callbacks, we don't want to unlock the spinlock
836 without removing lkb_cb_list; so empty lkb_cb_list is always
837 consistent with empty lkb_callbacks */
838
839 lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_cb_list);
840
841 /* rem_lkb_callback sets a new lkb_last_cast */
842 old_mode = lkb->lkb_last_cast.mode;
843
844 rv = dlm_rem_lkb_callback(lkb->lkb_resource->res_ls, lkb, &cb, &resid);
845 if (rv < 0) {
846 /* this shouldn't happen; lkb should have been removed from
847 list when resid was zero */
848 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
849 list_del_init(&lkb->lkb_cb_list);
850 spin_unlock(&proc->asts_spin);
851 /* removes ref for proc->asts, may cause lkb to be freed */
852 dlm_put_lkb(lkb);
853 goto try_another;
854 }
855 if (!resid)
856 list_del_init(&lkb->lkb_cb_list);
857 spin_unlock(&proc->asts_spin);
858
859 if (cb.flags & DLM_CB_SKIP) {
860 /* removes ref for proc->asts, may cause lkb to be freed */
861 if (!resid)
862 dlm_put_lkb(lkb);
863 goto try_another;
864 }
865
866 if (cb.flags & DLM_CB_CAST) {
867 new_mode = cb.mode;
868
869 if (!cb.sb_status && lkb->lkb_lksb->sb_lvbptr &&
870 dlm_lvb_operations[old_mode + 1][new_mode + 1])
871 copy_lvb = 1;
872
873 lkb->lkb_lksb->sb_status = cb.sb_status;
874 lkb->lkb_lksb->sb_flags = cb.sb_flags;
875 }
876
877 rv = copy_result_to_user(lkb->lkb_ua,
878 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
879 cb.flags, cb.mode, copy_lvb, buf, count);
880
881 /* removes ref for proc->asts, may cause lkb to be freed */
882 if (!resid)
883 dlm_put_lkb(lkb);
884
885 return rv;
886}
887
888static __poll_t device_poll(struct file *file, poll_table *wait)
889{
890 struct dlm_user_proc *proc = file->private_data;
891
892 poll_wait(file, &proc->wait, wait);
893
894 spin_lock(&proc->asts_spin);
895 if (!list_empty(&proc->asts)) {
896 spin_unlock(&proc->asts_spin);
897 return EPOLLIN | EPOLLRDNORM;
898 }
899 spin_unlock(&proc->asts_spin);
900 return 0;
901}
902
903int dlm_user_daemon_available(void)
904{
905 /* dlm_controld hasn't started (or, has started, but not
906 properly populated configfs) */
907
908 if (!dlm_our_nodeid())
909 return 0;
910
911 /* This is to deal with versions of dlm_controld that don't
912 know about the monitor device. We assume that if the
913 dlm_controld was started (above), but the monitor device
914 was never opened, that it's an old version. dlm_controld
915 should open the monitor device before populating configfs. */
916
917 if (dlm_monitor_unused)
918 return 1;
919
920 return atomic_read(&dlm_monitor_opened) ? 1 : 0;
921}
922
923static int ctl_device_open(struct inode *inode, struct file *file)
924{
925 file->private_data = NULL;
926 return 0;
927}
928
929static int ctl_device_close(struct inode *inode, struct file *file)
930{
931 return 0;
932}
933
934static int monitor_device_open(struct inode *inode, struct file *file)
935{
936 atomic_inc(&dlm_monitor_opened);
937 dlm_monitor_unused = 0;
938 return 0;
939}
940
941static int monitor_device_close(struct inode *inode, struct file *file)
942{
943 if (atomic_dec_and_test(&dlm_monitor_opened))
944 dlm_stop_lockspaces();
945 return 0;
946}
947
948static const struct file_operations device_fops = {
949 .open = device_open,
950 .release = device_close,
951 .read = device_read,
952 .write = device_write,
953 .poll = device_poll,
954 .owner = THIS_MODULE,
955 .llseek = noop_llseek,
956};
957
958static const struct file_operations ctl_device_fops = {
959 .open = ctl_device_open,
960 .release = ctl_device_close,
961 .read = device_read,
962 .write = device_write,
963 .owner = THIS_MODULE,
964 .llseek = noop_llseek,
965};
966
967static struct miscdevice ctl_device = {
968 .name = "dlm-control",
969 .fops = &ctl_device_fops,
970 .minor = MISC_DYNAMIC_MINOR,
971};
972
973static const struct file_operations monitor_device_fops = {
974 .open = monitor_device_open,
975 .release = monitor_device_close,
976 .owner = THIS_MODULE,
977 .llseek = noop_llseek,
978};
979
980static struct miscdevice monitor_device = {
981 .name = "dlm-monitor",
982 .fops = &monitor_device_fops,
983 .minor = MISC_DYNAMIC_MINOR,
984};
985
986int __init dlm_user_init(void)
987{
988 int error;
989
990 atomic_set(&dlm_monitor_opened, 0);
991
992 error = misc_register(&ctl_device);
993 if (error) {
994 log_print("misc_register failed for control device");
995 goto out;
996 }
997
998 error = misc_register(&monitor_device);
999 if (error) {
1000 log_print("misc_register failed for monitor device");
1001 misc_deregister(&ctl_device);
1002 }
1003 out:
1004 return error;
1005}
1006
1007void dlm_user_exit(void)
1008{
1009 misc_deregister(&ctl_device);
1010 misc_deregister(&monitor_device);
1011}
1012