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