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1/*
2 * Copyright (C) 2006-2010 Red Hat, Inc. All rights reserved.
3 *
4 * This copyrighted material is made available to anyone wishing to use,
5 * modify, copy, or redistribute it subject to the terms and conditions
6 * of the GNU General Public License v.2.
7 */
8
9#include <linux/miscdevice.h>
10#include <linux/init.h>
11#include <linux/wait.h>
12#include <linux/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
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006-2010 Red Hat, Inc. All rights reserved.
4 */
5
6#include <linux/miscdevice.h>
7#include <linux/init.h>
8#include <linux/wait.h>
9#include <linux/file.h>
10#include <linux/fs.h>
11#include <linux/poll.h>
12#include <linux/signal.h>
13#include <linux/spinlock.h>
14#include <linux/dlm.h>
15#include <linux/dlm_device.h>
16#include <linux/slab.h>
17#include <linux/sched/signal.h>
18
19#include <trace/events/dlm.h>
20
21#include "dlm_internal.h"
22#include "lockspace.h"
23#include "lock.h"
24#include "user.h"
25#include "ast.h"
26#include "config.h"
27#include "memory.h"
28
29static const char name_prefix[] = "dlm";
30static const struct file_operations device_fops;
31static atomic_t dlm_monitor_opened;
32static int dlm_monitor_unused = 1;
33
34#ifdef CONFIG_COMPAT
35
36struct dlm_lock_params32 {
37 __u8 mode;
38 __u8 namelen;
39 __u16 unused;
40 __u32 flags;
41 __u32 lkid;
42 __u32 parent;
43 __u64 xid;
44 __u64 timeout;
45 __u32 castparam;
46 __u32 castaddr;
47 __u32 bastparam;
48 __u32 bastaddr;
49 __u32 lksb;
50 char lvb[DLM_USER_LVB_LEN];
51 char name[];
52};
53
54struct dlm_write_request32 {
55 __u32 version[3];
56 __u8 cmd;
57 __u8 is64bit;
58 __u8 unused[2];
59
60 union {
61 struct dlm_lock_params32 lock;
62 struct dlm_lspace_params lspace;
63 struct dlm_purge_params purge;
64 } i;
65};
66
67struct dlm_lksb32 {
68 __u32 sb_status;
69 __u32 sb_lkid;
70 __u8 sb_flags;
71 __u32 sb_lvbptr;
72};
73
74struct dlm_lock_result32 {
75 __u32 version[3];
76 __u32 length;
77 __u32 user_astaddr;
78 __u32 user_astparam;
79 __u32 user_lksb;
80 struct dlm_lksb32 lksb;
81 __u8 bast_mode;
82 __u8 unused[3];
83 /* Offsets may be zero if no data is present */
84 __u32 lvb_offset;
85};
86
87static void compat_input(struct dlm_write_request *kb,
88 struct dlm_write_request32 *kb32,
89 int namelen)
90{
91 kb->version[0] = kb32->version[0];
92 kb->version[1] = kb32->version[1];
93 kb->version[2] = kb32->version[2];
94
95 kb->cmd = kb32->cmd;
96 kb->is64bit = kb32->is64bit;
97 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
98 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
99 kb->i.lspace.flags = kb32->i.lspace.flags;
100 kb->i.lspace.minor = kb32->i.lspace.minor;
101 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
102 } else if (kb->cmd == DLM_USER_PURGE) {
103 kb->i.purge.nodeid = kb32->i.purge.nodeid;
104 kb->i.purge.pid = kb32->i.purge.pid;
105 } else {
106 kb->i.lock.mode = kb32->i.lock.mode;
107 kb->i.lock.namelen = kb32->i.lock.namelen;
108 kb->i.lock.flags = kb32->i.lock.flags;
109 kb->i.lock.lkid = kb32->i.lock.lkid;
110 kb->i.lock.parent = kb32->i.lock.parent;
111 kb->i.lock.xid = kb32->i.lock.xid;
112 kb->i.lock.timeout = kb32->i.lock.timeout;
113 kb->i.lock.castparam = (__user void *)(long)kb32->i.lock.castparam;
114 kb->i.lock.castaddr = (__user void *)(long)kb32->i.lock.castaddr;
115 kb->i.lock.bastparam = (__user void *)(long)kb32->i.lock.bastparam;
116 kb->i.lock.bastaddr = (__user void *)(long)kb32->i.lock.bastaddr;
117 kb->i.lock.lksb = (__user void *)(long)kb32->i.lock.lksb;
118 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
119 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
120 }
121}
122
123static void compat_output(struct dlm_lock_result *res,
124 struct dlm_lock_result32 *res32)
125{
126 memset(res32, 0, sizeof(*res32));
127
128 res32->version[0] = res->version[0];
129 res32->version[1] = res->version[1];
130 res32->version[2] = res->version[2];
131
132 res32->user_astaddr = (__u32)(__force long)res->user_astaddr;
133 res32->user_astparam = (__u32)(__force long)res->user_astparam;
134 res32->user_lksb = (__u32)(__force long)res->user_lksb;
135 res32->bast_mode = res->bast_mode;
136
137 res32->lvb_offset = res->lvb_offset;
138 res32->length = res->length;
139
140 res32->lksb.sb_status = res->lksb.sb_status;
141 res32->lksb.sb_flags = res->lksb.sb_flags;
142 res32->lksb.sb_lkid = res->lksb.sb_lkid;
143 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
144}
145#endif
146
147/* should held proc->asts_spin lock */
148void dlm_purge_lkb_callbacks(struct dlm_lkb *lkb)
149{
150 struct dlm_callback *cb, *safe;
151
152 list_for_each_entry_safe(cb, safe, &lkb->lkb_callbacks, list) {
153 list_del(&cb->list);
154 kref_put(&cb->ref, dlm_release_callback);
155 }
156
157 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
158
159 /* invalidate */
160 dlm_callback_set_last_ptr(&lkb->lkb_last_cast, NULL);
161 dlm_callback_set_last_ptr(&lkb->lkb_last_cb, NULL);
162 lkb->lkb_last_bast_mode = -1;
163}
164
165/* Figure out if this lock is at the end of its life and no longer
166 available for the application to use. The lkb still exists until
167 the final ast is read. A lock becomes EOL in three situations:
168 1. a noqueue request fails with EAGAIN
169 2. an unlock completes with EUNLOCK
170 3. a cancel of a waiting request completes with ECANCEL/EDEADLK
171 An EOL lock needs to be removed from the process's list of locks.
172 And we can't allow any new operation on an EOL lock. This is
173 not related to the lifetime of the lkb struct which is managed
174 entirely by refcount. */
175
176static int lkb_is_endoflife(int mode, int status)
177{
178 switch (status) {
179 case -DLM_EUNLOCK:
180 return 1;
181 case -DLM_ECANCEL:
182 case -ETIMEDOUT:
183 case -EDEADLK:
184 case -EAGAIN:
185 if (mode == DLM_LOCK_IV)
186 return 1;
187 break;
188 }
189 return 0;
190}
191
192/* we could possibly check if the cancel of an orphan has resulted in the lkb
193 being removed and then remove that lkb from the orphans list and free it */
194
195void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
196 int status, uint32_t sbflags)
197{
198 struct dlm_ls *ls;
199 struct dlm_user_args *ua;
200 struct dlm_user_proc *proc;
201 int rv;
202
203 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) ||
204 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags))
205 return;
206
207 ls = lkb->lkb_resource->res_ls;
208 spin_lock(&ls->ls_clear_proc_locks);
209
210 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
211 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
212 lkb->ua so we can't try to use it. This second check is necessary
213 for cases where a completion ast is received for an operation that
214 began before clear_proc_locks did its cancel/unlock. */
215
216 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) ||
217 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags))
218 goto out;
219
220 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
221 ua = lkb->lkb_ua;
222 proc = ua->proc;
223
224 if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
225 goto out;
226
227 if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
228 set_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags);
229
230 spin_lock(&proc->asts_spin);
231
232 rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
233 switch (rv) {
234 case DLM_ENQUEUE_CALLBACK_FAILURE:
235 spin_unlock(&proc->asts_spin);
236 WARN_ON_ONCE(1);
237 goto out;
238 case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
239 kref_get(&lkb->lkb_ref);
240 list_add_tail(&lkb->lkb_cb_list, &proc->asts);
241 wake_up_interruptible(&proc->wait);
242 break;
243 case DLM_ENQUEUE_CALLBACK_SUCCESS:
244 break;
245 default:
246 WARN_ON_ONCE(1);
247 break;
248 }
249 spin_unlock(&proc->asts_spin);
250
251 if (test_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags)) {
252 /* N.B. spin_lock locks_spin, not asts_spin */
253 spin_lock(&proc->locks_spin);
254 if (!list_empty(&lkb->lkb_ownqueue)) {
255 list_del_init(&lkb->lkb_ownqueue);
256 dlm_put_lkb(lkb);
257 }
258 spin_unlock(&proc->locks_spin);
259 }
260 out:
261 spin_unlock(&ls->ls_clear_proc_locks);
262}
263
264static int device_user_lock(struct dlm_user_proc *proc,
265 struct dlm_lock_params *params)
266{
267 struct dlm_ls *ls;
268 struct dlm_user_args *ua;
269 uint32_t lkid;
270 int error = -ENOMEM;
271
272 ls = dlm_find_lockspace_local(proc->lockspace);
273 if (!ls)
274 return -ENOENT;
275
276 if (!params->castaddr || !params->lksb) {
277 error = -EINVAL;
278 goto out;
279 }
280
281 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
282 if (!ua)
283 goto out;
284 ua->proc = proc;
285 ua->user_lksb = params->lksb;
286 ua->castparam = params->castparam;
287 ua->castaddr = params->castaddr;
288 ua->bastparam = params->bastparam;
289 ua->bastaddr = params->bastaddr;
290 ua->xid = params->xid;
291
292 if (params->flags & DLM_LKF_CONVERT) {
293 error = dlm_user_convert(ls, ua,
294 params->mode, params->flags,
295 params->lkid, params->lvb);
296 } else if (params->flags & DLM_LKF_ORPHAN) {
297 error = dlm_user_adopt_orphan(ls, ua,
298 params->mode, params->flags,
299 params->name, params->namelen,
300 &lkid);
301 if (!error)
302 error = lkid;
303 } else {
304 error = dlm_user_request(ls, ua,
305 params->mode, params->flags,
306 params->name, params->namelen);
307 if (!error)
308 error = ua->lksb.sb_lkid;
309 }
310 out:
311 dlm_put_lockspace(ls);
312 return error;
313}
314
315static int device_user_unlock(struct dlm_user_proc *proc,
316 struct dlm_lock_params *params)
317{
318 struct dlm_ls *ls;
319 struct dlm_user_args *ua;
320 int error = -ENOMEM;
321
322 ls = dlm_find_lockspace_local(proc->lockspace);
323 if (!ls)
324 return -ENOENT;
325
326 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
327 if (!ua)
328 goto out;
329 ua->proc = proc;
330 ua->user_lksb = params->lksb;
331 ua->castparam = params->castparam;
332 ua->castaddr = params->castaddr;
333
334 if (params->flags & DLM_LKF_CANCEL)
335 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
336 else
337 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
338 params->lvb);
339 out:
340 dlm_put_lockspace(ls);
341 return error;
342}
343
344static int device_user_deadlock(struct dlm_user_proc *proc,
345 struct dlm_lock_params *params)
346{
347 struct dlm_ls *ls;
348 int error;
349
350 ls = dlm_find_lockspace_local(proc->lockspace);
351 if (!ls)
352 return -ENOENT;
353
354 error = dlm_user_deadlock(ls, params->flags, params->lkid);
355
356 dlm_put_lockspace(ls);
357 return error;
358}
359
360static int dlm_device_register(struct dlm_ls *ls, char *name)
361{
362 int error, len;
363
364 /* The device is already registered. This happens when the
365 lockspace is created multiple times from userspace. */
366 if (ls->ls_device.name)
367 return 0;
368
369 error = -ENOMEM;
370 len = strlen(name) + strlen(name_prefix) + 2;
371 ls->ls_device.name = kzalloc(len, GFP_NOFS);
372 if (!ls->ls_device.name)
373 goto fail;
374
375 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
376 name);
377 ls->ls_device.fops = &device_fops;
378 ls->ls_device.minor = MISC_DYNAMIC_MINOR;
379
380 error = misc_register(&ls->ls_device);
381 if (error) {
382 kfree(ls->ls_device.name);
383 /* this has to be set to NULL
384 * to avoid a double-free in dlm_device_deregister
385 */
386 ls->ls_device.name = NULL;
387 }
388fail:
389 return error;
390}
391
392int dlm_device_deregister(struct dlm_ls *ls)
393{
394 /* The device is not registered. This happens when the lockspace
395 was never used from userspace, or when device_create_lockspace()
396 calls dlm_release_lockspace() after the register fails. */
397 if (!ls->ls_device.name)
398 return 0;
399
400 misc_deregister(&ls->ls_device);
401 kfree(ls->ls_device.name);
402 return 0;
403}
404
405static int device_user_purge(struct dlm_user_proc *proc,
406 struct dlm_purge_params *params)
407{
408 struct dlm_ls *ls;
409 int error;
410
411 ls = dlm_find_lockspace_local(proc->lockspace);
412 if (!ls)
413 return -ENOENT;
414
415 error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
416
417 dlm_put_lockspace(ls);
418 return error;
419}
420
421static int device_create_lockspace(struct dlm_lspace_params *params)
422{
423 dlm_lockspace_t *lockspace;
424 struct dlm_ls *ls;
425 int error;
426
427 if (!capable(CAP_SYS_ADMIN))
428 return -EPERM;
429
430 error = dlm_new_user_lockspace(params->name, dlm_config.ci_cluster_name,
431 params->flags, DLM_USER_LVB_LEN, NULL,
432 NULL, NULL, &lockspace);
433 if (error)
434 return error;
435
436 ls = dlm_find_lockspace_local(lockspace);
437 if (!ls)
438 return -ENOENT;
439
440 error = dlm_device_register(ls, params->name);
441 dlm_put_lockspace(ls);
442
443 if (error)
444 dlm_release_lockspace(lockspace, 0);
445 else
446 error = ls->ls_device.minor;
447
448 return error;
449}
450
451static int device_remove_lockspace(struct dlm_lspace_params *params)
452{
453 dlm_lockspace_t *lockspace;
454 struct dlm_ls *ls;
455 int error, force = 0;
456
457 if (!capable(CAP_SYS_ADMIN))
458 return -EPERM;
459
460 ls = dlm_find_lockspace_device(params->minor);
461 if (!ls)
462 return -ENOENT;
463
464 if (params->flags & DLM_USER_LSFLG_FORCEFREE)
465 force = 2;
466
467 lockspace = ls->ls_local_handle;
468 dlm_put_lockspace(ls);
469
470 /* The final dlm_release_lockspace waits for references to go to
471 zero, so all processes will need to close their device for the
472 ls before the release will proceed. release also calls the
473 device_deregister above. Converting a positive return value
474 from release to zero means that userspace won't know when its
475 release was the final one, but it shouldn't need to know. */
476
477 error = dlm_release_lockspace(lockspace, force);
478 if (error > 0)
479 error = 0;
480 return error;
481}
482
483/* Check the user's version matches ours */
484static int check_version(struct dlm_write_request *req)
485{
486 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
487 (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
488 req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
489
490 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
491 "user (%d.%d.%d) kernel (%d.%d.%d)\n",
492 current->comm,
493 task_pid_nr(current),
494 req->version[0],
495 req->version[1],
496 req->version[2],
497 DLM_DEVICE_VERSION_MAJOR,
498 DLM_DEVICE_VERSION_MINOR,
499 DLM_DEVICE_VERSION_PATCH);
500 return -EINVAL;
501 }
502 return 0;
503}
504
505/*
506 * device_write
507 *
508 * device_user_lock
509 * dlm_user_request -> request_lock
510 * dlm_user_convert -> convert_lock
511 *
512 * device_user_unlock
513 * dlm_user_unlock -> unlock_lock
514 * dlm_user_cancel -> cancel_lock
515 *
516 * device_create_lockspace
517 * dlm_new_lockspace
518 *
519 * device_remove_lockspace
520 * dlm_release_lockspace
521 */
522
523/* a write to a lockspace device is a lock or unlock request, a write
524 to the control device is to create/remove a lockspace */
525
526static ssize_t device_write(struct file *file, const char __user *buf,
527 size_t count, loff_t *ppos)
528{
529 struct dlm_user_proc *proc = file->private_data;
530 struct dlm_write_request *kbuf;
531 int error;
532
533#ifdef CONFIG_COMPAT
534 if (count < sizeof(struct dlm_write_request32))
535#else
536 if (count < sizeof(struct dlm_write_request))
537#endif
538 return -EINVAL;
539
540 /*
541 * can't compare against COMPAT/dlm_write_request32 because
542 * we don't yet know if is64bit is zero
543 */
544 if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
545 return -EINVAL;
546
547 kbuf = memdup_user_nul(buf, count);
548 if (IS_ERR(kbuf))
549 return PTR_ERR(kbuf);
550
551 if (check_version(kbuf)) {
552 error = -EBADE;
553 goto out_free;
554 }
555
556#ifdef CONFIG_COMPAT
557 if (!kbuf->is64bit) {
558 struct dlm_write_request32 *k32buf;
559 int namelen = 0;
560
561 if (count > sizeof(struct dlm_write_request32))
562 namelen = count - sizeof(struct dlm_write_request32);
563
564 k32buf = (struct dlm_write_request32 *)kbuf;
565
566 /* add 1 after namelen so that the name string is terminated */
567 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
568 GFP_NOFS);
569 if (!kbuf) {
570 kfree(k32buf);
571 return -ENOMEM;
572 }
573
574 if (proc)
575 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
576
577 compat_input(kbuf, k32buf, namelen);
578 kfree(k32buf);
579 }
580#endif
581
582 /* do we really need this? can a write happen after a close? */
583 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
584 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
585 error = -EINVAL;
586 goto out_free;
587 }
588
589 error = -EINVAL;
590
591 switch (kbuf->cmd)
592 {
593 case DLM_USER_LOCK:
594 if (!proc) {
595 log_print("no locking on control device");
596 goto out_free;
597 }
598 error = device_user_lock(proc, &kbuf->i.lock);
599 break;
600
601 case DLM_USER_UNLOCK:
602 if (!proc) {
603 log_print("no locking on control device");
604 goto out_free;
605 }
606 error = device_user_unlock(proc, &kbuf->i.lock);
607 break;
608
609 case DLM_USER_DEADLOCK:
610 if (!proc) {
611 log_print("no locking on control device");
612 goto out_free;
613 }
614 error = device_user_deadlock(proc, &kbuf->i.lock);
615 break;
616
617 case DLM_USER_CREATE_LOCKSPACE:
618 if (proc) {
619 log_print("create/remove only on control device");
620 goto out_free;
621 }
622 error = device_create_lockspace(&kbuf->i.lspace);
623 break;
624
625 case DLM_USER_REMOVE_LOCKSPACE:
626 if (proc) {
627 log_print("create/remove only on control device");
628 goto out_free;
629 }
630 error = device_remove_lockspace(&kbuf->i.lspace);
631 break;
632
633 case DLM_USER_PURGE:
634 if (!proc) {
635 log_print("no locking on control device");
636 goto out_free;
637 }
638 error = device_user_purge(proc, &kbuf->i.purge);
639 break;
640
641 default:
642 log_print("Unknown command passed to DLM device : %d\n",
643 kbuf->cmd);
644 }
645
646 out_free:
647 kfree(kbuf);
648 return error;
649}
650
651/* Every process that opens the lockspace device has its own "proc" structure
652 hanging off the open file that's used to keep track of locks owned by the
653 process and asts that need to be delivered to the process. */
654
655static int device_open(struct inode *inode, struct file *file)
656{
657 struct dlm_user_proc *proc;
658 struct dlm_ls *ls;
659
660 ls = dlm_find_lockspace_device(iminor(inode));
661 if (!ls)
662 return -ENOENT;
663
664 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
665 if (!proc) {
666 dlm_put_lockspace(ls);
667 return -ENOMEM;
668 }
669
670 proc->lockspace = ls->ls_local_handle;
671 INIT_LIST_HEAD(&proc->asts);
672 INIT_LIST_HEAD(&proc->locks);
673 INIT_LIST_HEAD(&proc->unlocking);
674 spin_lock_init(&proc->asts_spin);
675 spin_lock_init(&proc->locks_spin);
676 init_waitqueue_head(&proc->wait);
677 file->private_data = proc;
678
679 return 0;
680}
681
682static int device_close(struct inode *inode, struct file *file)
683{
684 struct dlm_user_proc *proc = file->private_data;
685 struct dlm_ls *ls;
686
687 ls = dlm_find_lockspace_local(proc->lockspace);
688 if (!ls)
689 return -ENOENT;
690
691 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
692
693 dlm_clear_proc_locks(ls, proc);
694
695 /* at this point no more lkb's should exist for this lockspace,
696 so there's no chance of dlm_user_add_ast() being called and
697 looking for lkb->ua->proc */
698
699 kfree(proc);
700 file->private_data = NULL;
701
702 dlm_put_lockspace(ls);
703 dlm_put_lockspace(ls); /* for the find in device_open() */
704
705 /* FIXME: AUTOFREE: if this ls is no longer used do
706 device_remove_lockspace() */
707
708 return 0;
709}
710
711static int copy_result_to_user(struct dlm_user_args *ua, int compat,
712 uint32_t flags, int mode, int copy_lvb,
713 char __user *buf, size_t count)
714{
715#ifdef CONFIG_COMPAT
716 struct dlm_lock_result32 result32;
717#endif
718 struct dlm_lock_result result;
719 void *resultptr;
720 int error=0;
721 int len;
722 int struct_len;
723
724 memset(&result, 0, sizeof(struct dlm_lock_result));
725 result.version[0] = DLM_DEVICE_VERSION_MAJOR;
726 result.version[1] = DLM_DEVICE_VERSION_MINOR;
727 result.version[2] = DLM_DEVICE_VERSION_PATCH;
728 memcpy(&result.lksb, &ua->lksb, offsetof(struct dlm_lksb, sb_lvbptr));
729 result.user_lksb = ua->user_lksb;
730
731 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
732 in a conversion unless the conversion is successful. See code
733 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though,
734 notes that a new blocking AST address and parameter are set even if
735 the conversion fails, so maybe we should just do that. */
736
737 if (flags & DLM_CB_BAST) {
738 result.user_astaddr = ua->bastaddr;
739 result.user_astparam = ua->bastparam;
740 result.bast_mode = mode;
741 } else {
742 result.user_astaddr = ua->castaddr;
743 result.user_astparam = ua->castparam;
744 }
745
746#ifdef CONFIG_COMPAT
747 if (compat)
748 len = sizeof(struct dlm_lock_result32);
749 else
750#endif
751 len = sizeof(struct dlm_lock_result);
752 struct_len = len;
753
754 /* copy lvb to userspace if there is one, it's been updated, and
755 the user buffer has space for it */
756
757 if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
758 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
759 DLM_USER_LVB_LEN)) {
760 error = -EFAULT;
761 goto out;
762 }
763
764 result.lvb_offset = len;
765 len += DLM_USER_LVB_LEN;
766 }
767
768 result.length = len;
769 resultptr = &result;
770#ifdef CONFIG_COMPAT
771 if (compat) {
772 compat_output(&result, &result32);
773 resultptr = &result32;
774 }
775#endif
776
777 if (copy_to_user(buf, resultptr, struct_len))
778 error = -EFAULT;
779 else
780 error = len;
781 out:
782 return error;
783}
784
785static int copy_version_to_user(char __user *buf, size_t count)
786{
787 struct dlm_device_version ver;
788
789 memset(&ver, 0, sizeof(struct dlm_device_version));
790 ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
791 ver.version[1] = DLM_DEVICE_VERSION_MINOR;
792 ver.version[2] = DLM_DEVICE_VERSION_PATCH;
793
794 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
795 return -EFAULT;
796 return sizeof(struct dlm_device_version);
797}
798
799/* a read returns a single ast described in a struct dlm_lock_result */
800
801static ssize_t device_read(struct file *file, char __user *buf, size_t count,
802 loff_t *ppos)
803{
804 struct dlm_user_proc *proc = file->private_data;
805 struct dlm_lkb *lkb;
806 DECLARE_WAITQUEUE(wait, current);
807 struct dlm_callback *cb;
808 int rv, ret;
809
810 if (count == sizeof(struct dlm_device_version)) {
811 rv = copy_version_to_user(buf, count);
812 return rv;
813 }
814
815 if (!proc) {
816 log_print("non-version read from control device %zu", count);
817 return -EINVAL;
818 }
819
820#ifdef CONFIG_COMPAT
821 if (count < sizeof(struct dlm_lock_result32))
822#else
823 if (count < sizeof(struct dlm_lock_result))
824#endif
825 return -EINVAL;
826
827 try_another:
828
829 /* do we really need this? can a read happen after a close? */
830 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
831 return -EINVAL;
832
833 spin_lock(&proc->asts_spin);
834 if (list_empty(&proc->asts)) {
835 if (file->f_flags & O_NONBLOCK) {
836 spin_unlock(&proc->asts_spin);
837 return -EAGAIN;
838 }
839
840 add_wait_queue(&proc->wait, &wait);
841
842 repeat:
843 set_current_state(TASK_INTERRUPTIBLE);
844 if (list_empty(&proc->asts) && !signal_pending(current)) {
845 spin_unlock(&proc->asts_spin);
846 schedule();
847 spin_lock(&proc->asts_spin);
848 goto repeat;
849 }
850 set_current_state(TASK_RUNNING);
851 remove_wait_queue(&proc->wait, &wait);
852
853 if (signal_pending(current)) {
854 spin_unlock(&proc->asts_spin);
855 return -ERESTARTSYS;
856 }
857 }
858
859 /* if we empty lkb_callbacks, we don't want to unlock the spinlock
860 without removing lkb_cb_list; so empty lkb_cb_list is always
861 consistent with empty lkb_callbacks */
862
863 lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list);
864
865 rv = dlm_dequeue_lkb_callback(lkb, &cb);
866 switch (rv) {
867 case DLM_DEQUEUE_CALLBACK_EMPTY:
868 /* this shouldn't happen; lkb should have been removed from
869 * list when last item was dequeued
870 */
871 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
872 list_del_init(&lkb->lkb_cb_list);
873 spin_unlock(&proc->asts_spin);
874 /* removes ref for proc->asts, may cause lkb to be freed */
875 dlm_put_lkb(lkb);
876 WARN_ON_ONCE(1);
877 goto try_another;
878 case DLM_DEQUEUE_CALLBACK_LAST:
879 list_del_init(&lkb->lkb_cb_list);
880 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
881 break;
882 case DLM_DEQUEUE_CALLBACK_SUCCESS:
883 break;
884 default:
885 WARN_ON_ONCE(1);
886 break;
887 }
888 spin_unlock(&proc->asts_spin);
889
890 if (cb->flags & DLM_CB_BAST) {
891 trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode);
892 } else if (cb->flags & DLM_CB_CAST) {
893 lkb->lkb_lksb->sb_status = cb->sb_status;
894 lkb->lkb_lksb->sb_flags = cb->sb_flags;
895 trace_dlm_ast(lkb->lkb_resource->res_ls, lkb);
896 }
897
898 ret = copy_result_to_user(lkb->lkb_ua,
899 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
900 cb->flags, cb->mode, cb->copy_lvb, buf, count);
901
902 kref_put(&cb->ref, dlm_release_callback);
903
904 /* removes ref for proc->asts, may cause lkb to be freed */
905 if (rv == DLM_DEQUEUE_CALLBACK_LAST)
906 dlm_put_lkb(lkb);
907
908 return ret;
909}
910
911static __poll_t device_poll(struct file *file, poll_table *wait)
912{
913 struct dlm_user_proc *proc = file->private_data;
914
915 poll_wait(file, &proc->wait, wait);
916
917 spin_lock(&proc->asts_spin);
918 if (!list_empty(&proc->asts)) {
919 spin_unlock(&proc->asts_spin);
920 return EPOLLIN | EPOLLRDNORM;
921 }
922 spin_unlock(&proc->asts_spin);
923 return 0;
924}
925
926int dlm_user_daemon_available(void)
927{
928 /* dlm_controld hasn't started (or, has started, but not
929 properly populated configfs) */
930
931 if (!dlm_our_nodeid())
932 return 0;
933
934 /* This is to deal with versions of dlm_controld that don't
935 know about the monitor device. We assume that if the
936 dlm_controld was started (above), but the monitor device
937 was never opened, that it's an old version. dlm_controld
938 should open the monitor device before populating configfs. */
939
940 if (dlm_monitor_unused)
941 return 1;
942
943 return atomic_read(&dlm_monitor_opened) ? 1 : 0;
944}
945
946static int ctl_device_open(struct inode *inode, struct file *file)
947{
948 file->private_data = NULL;
949 return 0;
950}
951
952static int ctl_device_close(struct inode *inode, struct file *file)
953{
954 return 0;
955}
956
957static int monitor_device_open(struct inode *inode, struct file *file)
958{
959 atomic_inc(&dlm_monitor_opened);
960 dlm_monitor_unused = 0;
961 return 0;
962}
963
964static int monitor_device_close(struct inode *inode, struct file *file)
965{
966 if (atomic_dec_and_test(&dlm_monitor_opened))
967 dlm_stop_lockspaces();
968 return 0;
969}
970
971static const struct file_operations device_fops = {
972 .open = device_open,
973 .release = device_close,
974 .read = device_read,
975 .write = device_write,
976 .poll = device_poll,
977 .owner = THIS_MODULE,
978 .llseek = noop_llseek,
979};
980
981static const struct file_operations ctl_device_fops = {
982 .open = ctl_device_open,
983 .release = ctl_device_close,
984 .read = device_read,
985 .write = device_write,
986 .owner = THIS_MODULE,
987 .llseek = noop_llseek,
988};
989
990static struct miscdevice ctl_device = {
991 .name = "dlm-control",
992 .fops = &ctl_device_fops,
993 .minor = MISC_DYNAMIC_MINOR,
994};
995
996static const struct file_operations monitor_device_fops = {
997 .open = monitor_device_open,
998 .release = monitor_device_close,
999 .owner = THIS_MODULE,
1000 .llseek = noop_llseek,
1001};
1002
1003static struct miscdevice monitor_device = {
1004 .name = "dlm-monitor",
1005 .fops = &monitor_device_fops,
1006 .minor = MISC_DYNAMIC_MINOR,
1007};
1008
1009int __init dlm_user_init(void)
1010{
1011 int error;
1012
1013 atomic_set(&dlm_monitor_opened, 0);
1014
1015 error = misc_register(&ctl_device);
1016 if (error) {
1017 log_print("misc_register failed for control device");
1018 goto out;
1019 }
1020
1021 error = misc_register(&monitor_device);
1022 if (error) {
1023 log_print("misc_register failed for monitor device");
1024 misc_deregister(&ctl_device);
1025 }
1026 out:
1027 return error;
1028}
1029
1030void dlm_user_exit(void)
1031{
1032 misc_deregister(&ctl_device);
1033 misc_deregister(&monitor_device);
1034}
1035