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