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x86: early_ioremap(), debugging
[wrt350n-kernel.git] / drivers / md / dm-ioctl.c
blob9627fa0f9470cfdb4055199e83eb68c7f8a5f18f
1 /*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8 #include "dm.h"
9
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/miscdevice.h>
13 #include <linux/init.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/dm-ioctl.h>
17 #include <linux/hdreg.h>
18
19 #include <asm/uaccess.h>
20
21 #define DM_MSG_PREFIX "ioctl"
22 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
23
24 /*-----------------------------------------------------------------
25 * The ioctl interface needs to be able to look up devices by
26 * name or uuid.
27 *---------------------------------------------------------------*/
28 struct hash_cell {
29 struct list_head name_list;
30 struct list_head uuid_list;
31
32 char *name;
33 char *uuid;
34 struct mapped_device *md;
35 struct dm_table *new_map;
36 };
37
38 struct vers_iter {
39 size_t param_size;
40 struct dm_target_versions *vers, *old_vers;
41 char *end;
42 uint32_t flags;
43 };
44
45
46 #define NUM_BUCKETS 64
47 #define MASK_BUCKETS (NUM_BUCKETS - 1)
48 static struct list_head _name_buckets[NUM_BUCKETS];
49 static struct list_head _uuid_buckets[NUM_BUCKETS];
50
51 static void dm_hash_remove_all(int keep_open_devices);
52
53 /*
54 * Guards access to both hash tables.
55 */
56 static DECLARE_RWSEM(_hash_lock);
57
58 static void init_buckets(struct list_head *buckets)
59 {
60 unsigned int i;
61
62 for (i = 0; i < NUM_BUCKETS; i++)
63 INIT_LIST_HEAD(buckets + i);
64 }
65
66 static int dm_hash_init(void)
67 {
68 init_buckets(_name_buckets);
69 init_buckets(_uuid_buckets);
70 return 0;
71 }
72
73 static void dm_hash_exit(void)
74 {
75 dm_hash_remove_all(0);
76 }
77
78 /*-----------------------------------------------------------------
79 * Hash function:
80 * We're not really concerned with the str hash function being
81 * fast since it's only used by the ioctl interface.
82 *---------------------------------------------------------------*/
83 static unsigned int hash_str(const char *str)
84 {
85 const unsigned int hash_mult = 2654435387U;
86 unsigned int h = 0;
87
88 while (*str)
89 h = (h + (unsigned int) *str++) * hash_mult;
90
91 return h & MASK_BUCKETS;
92 }
93
94 /*-----------------------------------------------------------------
95 * Code for looking up a device by name
96 *---------------------------------------------------------------*/
97 static struct hash_cell *__get_name_cell(const char *str)
98 {
99 struct hash_cell *hc;
100 unsigned int h = hash_str(str);
101
102 list_for_each_entry (hc, _name_buckets + h, name_list)
103 if (!strcmp(hc->name, str)) {
104 dm_get(hc->md);
105 return hc;
106 }
107
108 return NULL;
109 }
110
111 static struct hash_cell *__get_uuid_cell(const char *str)
112 {
113 struct hash_cell *hc;
114 unsigned int h = hash_str(str);
115
116 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
117 if (!strcmp(hc->uuid, str)) {
118 dm_get(hc->md);
119 return hc;
120 }
121
122 return NULL;
123 }
124
125 /*-----------------------------------------------------------------
126 * Inserting, removing and renaming a device.
127 *---------------------------------------------------------------*/
128 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
129 struct mapped_device *md)
130 {
131 struct hash_cell *hc;
132
133 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
134 if (!hc)
135 return NULL;
136
137 hc->name = kstrdup(name, GFP_KERNEL);
138 if (!hc->name) {
139 kfree(hc);
140 return NULL;
141 }
142
143 if (!uuid)
144 hc->uuid = NULL;
145
146 else {
147 hc->uuid = kstrdup(uuid, GFP_KERNEL);
148 if (!hc->uuid) {
149 kfree(hc->name);
150 kfree(hc);
151 return NULL;
152 }
153 }
154
155 INIT_LIST_HEAD(&hc->name_list);
156 INIT_LIST_HEAD(&hc->uuid_list);
157 hc->md = md;
158 hc->new_map = NULL;
159 return hc;
160 }
161
162 static void free_cell(struct hash_cell *hc)
163 {
164 if (hc) {
165 kfree(hc->name);
166 kfree(hc->uuid);
167 kfree(hc);
168 }
169 }
170
171 /*
172 * The kdev_t and uuid of a device can never change once it is
173 * initially inserted.
174 */
175 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
176 {
177 struct hash_cell *cell, *hc;
178
179 /*
180 * Allocate the new cells.
181 */
182 cell = alloc_cell(name, uuid, md);
183 if (!cell)
184 return -ENOMEM;
185
186 /*
187 * Insert the cell into both hash tables.
188 */
189 down_write(&_hash_lock);
190 hc = __get_name_cell(name);
191 if (hc) {
192 dm_put(hc->md);
193 goto bad;
194 }
195
196 list_add(&cell->name_list, _name_buckets + hash_str(name));
197
198 if (uuid) {
199 hc = __get_uuid_cell(uuid);
200 if (hc) {
201 list_del(&cell->name_list);
202 dm_put(hc->md);
203 goto bad;
204 }
205 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
206 }
207 dm_get(md);
208 dm_set_mdptr(md, cell);
209 up_write(&_hash_lock);
210
211 return 0;
212
213 bad:
214 up_write(&_hash_lock);
215 free_cell(cell);
216 return -EBUSY;
217 }
218
219 static void __hash_remove(struct hash_cell *hc)
220 {
221 struct dm_table *table;
222
223 /* remove from the dev hash */
224 list_del(&hc->uuid_list);
225 list_del(&hc->name_list);
226 dm_set_mdptr(hc->md, NULL);
227
228 table = dm_get_table(hc->md);
229 if (table) {
230 dm_table_event(table);
231 dm_table_put(table);
232 }
233
234 if (hc->new_map)
235 dm_table_put(hc->new_map);
236 dm_put(hc->md);
237 free_cell(hc);
238 }
239
240 static void dm_hash_remove_all(int keep_open_devices)
241 {
242 int i, dev_skipped, dev_removed;
243 struct hash_cell *hc;
244 struct list_head *tmp, *n;
245
246 down_write(&_hash_lock);
247
248 retry:
249 dev_skipped = dev_removed = 0;
250 for (i = 0; i < NUM_BUCKETS; i++) {
251 list_for_each_safe (tmp, n, _name_buckets + i) {
252 hc = list_entry(tmp, struct hash_cell, name_list);
253
254 if (keep_open_devices &&
255 dm_lock_for_deletion(hc->md)) {
256 dev_skipped++;
257 continue;
258 }
259 __hash_remove(hc);
260 dev_removed = 1;
261 }
262 }
263
264 /*
265 * Some mapped devices may be using other mapped devices, so if any
266 * still exist, repeat until we make no further progress.
267 */
268 if (dev_skipped) {
269 if (dev_removed)
270 goto retry;
271
272 DMWARN("remove_all left %d open device(s)", dev_skipped);
273 }
274
275 up_write(&_hash_lock);
276 }
277
278 static int dm_hash_rename(const char *old, const char *new)
279 {
280 char *new_name, *old_name;
281 struct hash_cell *hc;
282 struct dm_table *table;
283
284 /*
285 * duplicate new.
286 */
287 new_name = kstrdup(new, GFP_KERNEL);
288 if (!new_name)
289 return -ENOMEM;
290
291 down_write(&_hash_lock);
292
293 /*
294 * Is new free ?
295 */
296 hc = __get_name_cell(new);
297 if (hc) {
298 DMWARN("asked to rename to an already existing name %s -> %s",
299 old, new);
300 dm_put(hc->md);
301 up_write(&_hash_lock);
302 kfree(new_name);
303 return -EBUSY;
304 }
305
306 /*
307 * Is there such a device as 'old' ?
308 */
309 hc = __get_name_cell(old);
310 if (!hc) {
311 DMWARN("asked to rename a non existent device %s -> %s",
312 old, new);
313 up_write(&_hash_lock);
314 kfree(new_name);
315 return -ENXIO;
316 }
317
318 /*
319 * rename and move the name cell.
320 */
321 list_del(&hc->name_list);
322 old_name = hc->name;
323 hc->name = new_name;
324 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
325
326 /*
327 * Wake up any dm event waiters.
328 */
329 table = dm_get_table(hc->md);
330 if (table) {
331 dm_table_event(table);
332 dm_table_put(table);
333 }
334
335 dm_kobject_uevent(hc->md);
336
337 dm_put(hc->md);
338 up_write(&_hash_lock);
339 kfree(old_name);
340 return 0;
341 }
342
343 /*-----------------------------------------------------------------
344 * Implementation of the ioctl commands
345 *---------------------------------------------------------------*/
346 /*
347 * All the ioctl commands get dispatched to functions with this
348 * prototype.
349 */
350 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
351
352 static int remove_all(struct dm_ioctl *param, size_t param_size)
353 {
354 dm_hash_remove_all(1);
355 param->data_size = 0;
356 return 0;
357 }
358
359 /*
360 * Round up the ptr to an 8-byte boundary.
361 */
362 #define ALIGN_MASK 7
363 static inline void *align_ptr(void *ptr)
364 {
365 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
366 }
367
368 /*
369 * Retrieves the data payload buffer from an already allocated
370 * struct dm_ioctl.
371 */
372 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
373 size_t *len)
374 {
375 param->data_start = align_ptr(param + 1) - (void *) param;
376
377 if (param->data_start < param_size)
378 *len = param_size - param->data_start;
379 else
380 *len = 0;
381
382 return ((void *) param) + param->data_start;
383 }
384
385 static int list_devices(struct dm_ioctl *param, size_t param_size)
386 {
387 unsigned int i;
388 struct hash_cell *hc;
389 size_t len, needed = 0;
390 struct gendisk *disk;
391 struct dm_name_list *nl, *old_nl = NULL;
392
393 down_write(&_hash_lock);
394
395 /*
396 * Loop through all the devices working out how much
397 * space we need.
398 */
399 for (i = 0; i < NUM_BUCKETS; i++) {
400 list_for_each_entry (hc, _name_buckets + i, name_list) {
401 needed += sizeof(struct dm_name_list);
402 needed += strlen(hc->name) + 1;
403 needed += ALIGN_MASK;
404 }
405 }
406
407 /*
408 * Grab our output buffer.
409 */
410 nl = get_result_buffer(param, param_size, &len);
411 if (len < needed) {
412 param->flags |= DM_BUFFER_FULL_FLAG;
413 goto out;
414 }
415 param->data_size = param->data_start + needed;
416
417 nl->dev = 0; /* Flags no data */
418
419 /*
420 * Now loop through filling out the names.
421 */
422 for (i = 0; i < NUM_BUCKETS; i++) {
423 list_for_each_entry (hc, _name_buckets + i, name_list) {
424 if (old_nl)
425 old_nl->next = (uint32_t) ((void *) nl -
426 (void *) old_nl);
427 disk = dm_disk(hc->md);
428 nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
429 nl->next = 0;
430 strcpy(nl->name, hc->name);
431
432 old_nl = nl;
433 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
434 }
435 }
436
437 out:
438 up_write(&_hash_lock);
439 return 0;
440 }
441
442 static void list_version_get_needed(struct target_type *tt, void *needed_param)
443 {
444 size_t *needed = needed_param;
445
446 *needed += sizeof(struct dm_target_versions);
447 *needed += strlen(tt->name);
448 *needed += ALIGN_MASK;
449 }
450
451 static void list_version_get_info(struct target_type *tt, void *param)
452 {
453 struct vers_iter *info = param;
454
455 /* Check space - it might have changed since the first iteration */
456 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
457 info->end) {
458
459 info->flags = DM_BUFFER_FULL_FLAG;
460 return;
461 }
462
463 if (info->old_vers)
464 info->old_vers->next = (uint32_t) ((void *)info->vers -
465 (void *)info->old_vers);
466 info->vers->version[0] = tt->version[0];
467 info->vers->version[1] = tt->version[1];
468 info->vers->version[2] = tt->version[2];
469 info->vers->next = 0;
470 strcpy(info->vers->name, tt->name);
471
472 info->old_vers = info->vers;
473 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
474 }
475
476 static int list_versions(struct dm_ioctl *param, size_t param_size)
477 {
478 size_t len, needed = 0;
479 struct dm_target_versions *vers;
480 struct vers_iter iter_info;
481
482 /*
483 * Loop through all the devices working out how much
484 * space we need.
485 */
486 dm_target_iterate(list_version_get_needed, &needed);
487
488 /*
489 * Grab our output buffer.
490 */
491 vers = get_result_buffer(param, param_size, &len);
492 if (len < needed) {
493 param->flags |= DM_BUFFER_FULL_FLAG;
494 goto out;
495 }
496 param->data_size = param->data_start + needed;
497
498 iter_info.param_size = param_size;
499 iter_info.old_vers = NULL;
500 iter_info.vers = vers;
501 iter_info.flags = 0;
502 iter_info.end = (char *)vers+len;
503
504 /*
505 * Now loop through filling out the names & versions.
506 */
507 dm_target_iterate(list_version_get_info, &iter_info);
508 param->flags |= iter_info.flags;
509
510 out:
511 return 0;
512 }
513
514
515
516 static int check_name(const char *name)
517 {
518 if (strchr(name, '/')) {
519 DMWARN("invalid device name");
520 return -EINVAL;
521 }
522
523 return 0;
524 }
525
526 /*
527 * Fills in a dm_ioctl structure, ready for sending back to
528 * userland.
529 */
530 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
531 {
532 struct gendisk *disk = dm_disk(md);
533 struct dm_table *table;
534
535 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
536 DM_ACTIVE_PRESENT_FLAG);
537
538 if (dm_suspended(md))
539 param->flags |= DM_SUSPEND_FLAG;
540
541 param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
542
543 /*
544 * Yes, this will be out of date by the time it gets back
545 * to userland, but it is still very useful for
546 * debugging.
547 */
548 param->open_count = dm_open_count(md);
549
550 if (disk->policy)
551 param->flags |= DM_READONLY_FLAG;
552
553 param->event_nr = dm_get_event_nr(md);
554
555 table = dm_get_table(md);
556 if (table) {
557 param->flags |= DM_ACTIVE_PRESENT_FLAG;
558 param->target_count = dm_table_get_num_targets(table);
559 dm_table_put(table);
560 } else
561 param->target_count = 0;
562
563 return 0;
564 }
565
566 static int dev_create(struct dm_ioctl *param, size_t param_size)
567 {
568 int r, m = DM_ANY_MINOR;
569 struct mapped_device *md;
570
571 r = check_name(param->name);
572 if (r)
573 return r;
574
575 if (param->flags & DM_PERSISTENT_DEV_FLAG)
576 m = MINOR(huge_decode_dev(param->dev));
577
578 r = dm_create(m, &md);
579 if (r)
580 return r;
581
582 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
583 if (r) {
584 dm_put(md);
585 return r;
586 }
587
588 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
589
590 r = __dev_status(md, param);
591 dm_put(md);
592
593 return r;
594 }
595
596 /*
597 * Always use UUID for lookups if it's present, otherwise use name or dev.
598 */
599 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
600 {
601 struct mapped_device *md;
602 void *mdptr = NULL;
603
604 if (*param->uuid)
605 return __get_uuid_cell(param->uuid);
606
607 if (*param->name)
608 return __get_name_cell(param->name);
609
610 md = dm_get_md(huge_decode_dev(param->dev));
611 if (!md)
612 goto out;
613
614 mdptr = dm_get_mdptr(md);
615 if (!mdptr)
616 dm_put(md);
617
618 out:
619 return mdptr;
620 }
621
622 static struct mapped_device *find_device(struct dm_ioctl *param)
623 {
624 struct hash_cell *hc;
625 struct mapped_device *md = NULL;
626
627 down_read(&_hash_lock);
628 hc = __find_device_hash_cell(param);
629 if (hc) {
630 md = hc->md;
631
632 /*
633 * Sneakily write in both the name and the uuid
634 * while we have the cell.
635 */
636 strncpy(param->name, hc->name, sizeof(param->name));
637 if (hc->uuid)
638 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
639 else
640 param->uuid[0] = '\0';
641
642 if (hc->new_map)
643 param->flags |= DM_INACTIVE_PRESENT_FLAG;
644 else
645 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
646 }
647 up_read(&_hash_lock);
648
649 return md;
650 }
651
652 static int dev_remove(struct dm_ioctl *param, size_t param_size)
653 {
654 struct hash_cell *hc;
655 struct mapped_device *md;
656 int r;
657
658 down_write(&_hash_lock);
659 hc = __find_device_hash_cell(param);
660
661 if (!hc) {
662 DMWARN("device doesn't appear to be in the dev hash table.");
663 up_write(&_hash_lock);
664 return -ENXIO;
665 }
666
667 md = hc->md;
668
669 /*
670 * Ensure the device is not open and nothing further can open it.
671 */
672 r = dm_lock_for_deletion(md);
673 if (r) {
674 DMWARN("unable to remove open device %s", hc->name);
675 up_write(&_hash_lock);
676 dm_put(md);
677 return r;
678 }
679
680 __hash_remove(hc);
681 up_write(&_hash_lock);
682 dm_put(md);
683 param->data_size = 0;
684 return 0;
685 }
686
687 /*
688 * Check a string doesn't overrun the chunk of
689 * memory we copied from userland.
690 */
691 static int invalid_str(char *str, void *end)
692 {
693 while ((void *) str < end)
694 if (!*str++)
695 return 0;
696
697 return -EINVAL;
698 }
699
700 static int dev_rename(struct dm_ioctl *param, size_t param_size)
701 {
702 int r;
703 char *new_name = (char *) param + param->data_start;
704
705 if (new_name < (char *) param->data ||
706 invalid_str(new_name, (void *) param + param_size)) {
707 DMWARN("Invalid new logical volume name supplied.");
708 return -EINVAL;
709 }
710
711 r = check_name(new_name);
712 if (r)
713 return r;
714
715 param->data_size = 0;
716 return dm_hash_rename(param->name, new_name);
717 }
718
719 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
720 {
721 int r = -EINVAL, x;
722 struct mapped_device *md;
723 struct hd_geometry geometry;
724 unsigned long indata[4];
725 char *geostr = (char *) param + param->data_start;
726
727 md = find_device(param);
728 if (!md)
729 return -ENXIO;
730
731 if (geostr < (char *) param->data ||
732 invalid_str(geostr, (void *) param + param_size)) {
733 DMWARN("Invalid geometry supplied.");
734 goto out;
735 }
736
737 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
738 indata + 1, indata + 2, indata + 3);
739
740 if (x != 4) {
741 DMWARN("Unable to interpret geometry settings.");
742 goto out;
743 }
744
745 if (indata[0] > 65535 || indata[1] > 255 ||
746 indata[2] > 255 || indata[3] > ULONG_MAX) {
747 DMWARN("Geometry exceeds range limits.");
748 goto out;
749 }
750
751 geometry.cylinders = indata[0];
752 geometry.heads = indata[1];
753 geometry.sectors = indata[2];
754 geometry.start = indata[3];
755
756 r = dm_set_geometry(md, &geometry);
757 if (!r)
758 r = __dev_status(md, param);
759
760 param->data_size = 0;
761
762 out:
763 dm_put(md);
764 return r;
765 }
766
767 static int do_suspend(struct dm_ioctl *param)
768 {
769 int r = 0;
770 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
771 struct mapped_device *md;
772
773 md = find_device(param);
774 if (!md)
775 return -ENXIO;
776
777 if (param->flags & DM_SKIP_LOCKFS_FLAG)
778 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
779 if (param->flags & DM_NOFLUSH_FLAG)
780 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
781
782 if (!dm_suspended(md))
783 r = dm_suspend(md, suspend_flags);
784
785 if (!r)
786 r = __dev_status(md, param);
787
788 dm_put(md);
789 return r;
790 }
791
792 static int do_resume(struct dm_ioctl *param)
793 {
794 int r = 0;
795 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
796 struct hash_cell *hc;
797 struct mapped_device *md;
798 struct dm_table *new_map;
799
800 down_write(&_hash_lock);
801
802 hc = __find_device_hash_cell(param);
803 if (!hc) {
804 DMWARN("device doesn't appear to be in the dev hash table.");
805 up_write(&_hash_lock);
806 return -ENXIO;
807 }
808
809 md = hc->md;
810
811 new_map = hc->new_map;
812 hc->new_map = NULL;
813 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
814
815 up_write(&_hash_lock);
816
817 /* Do we need to load a new map ? */
818 if (new_map) {
819 /* Suspend if it isn't already suspended */
820 if (param->flags & DM_SKIP_LOCKFS_FLAG)
821 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
822 if (param->flags & DM_NOFLUSH_FLAG)
823 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
824 if (!dm_suspended(md))
825 dm_suspend(md, suspend_flags);
826
827 r = dm_swap_table(md, new_map);
828 if (r) {
829 dm_put(md);
830 dm_table_put(new_map);
831 return r;
832 }
833
834 if (dm_table_get_mode(new_map) & FMODE_WRITE)
835 set_disk_ro(dm_disk(md), 0);
836 else
837 set_disk_ro(dm_disk(md), 1);
838
839 dm_table_put(new_map);
840 }
841
842 if (dm_suspended(md))
843 r = dm_resume(md);
844
845 if (!r)
846 r = __dev_status(md, param);
847
848 dm_put(md);
849 return r;
850 }
851
852 /*
853 * Set or unset the suspension state of a device.
854 * If the device already is in the requested state we just return its status.
855 */
856 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
857 {
858 if (param->flags & DM_SUSPEND_FLAG)
859 return do_suspend(param);
860
861 return do_resume(param);
862 }
863
864 /*
865 * Copies device info back to user space, used by
866 * the create and info ioctls.
867 */
868 static int dev_status(struct dm_ioctl *param, size_t param_size)
869 {
870 int r;
871 struct mapped_device *md;
872
873 md = find_device(param);
874 if (!md)
875 return -ENXIO;
876
877 r = __dev_status(md, param);
878 dm_put(md);
879 return r;
880 }
881
882 /*
883 * Build up the status struct for each target
884 */
885 static void retrieve_status(struct dm_table *table,
886 struct dm_ioctl *param, size_t param_size)
887 {
888 unsigned int i, num_targets;
889 struct dm_target_spec *spec;
890 char *outbuf, *outptr;
891 status_type_t type;
892 size_t remaining, len, used = 0;
893
894 outptr = outbuf = get_result_buffer(param, param_size, &len);
895
896 if (param->flags & DM_STATUS_TABLE_FLAG)
897 type = STATUSTYPE_TABLE;
898 else
899 type = STATUSTYPE_INFO;
900
901 /* Get all the target info */
902 num_targets = dm_table_get_num_targets(table);
903 for (i = 0; i < num_targets; i++) {
904 struct dm_target *ti = dm_table_get_target(table, i);
905
906 remaining = len - (outptr - outbuf);
907 if (remaining <= sizeof(struct dm_target_spec)) {
908 param->flags |= DM_BUFFER_FULL_FLAG;
909 break;
910 }
911
912 spec = (struct dm_target_spec *) outptr;
913
914 spec->status = 0;
915 spec->sector_start = ti->begin;
916 spec->length = ti->len;
917 strncpy(spec->target_type, ti->type->name,
918 sizeof(spec->target_type));
919
920 outptr += sizeof(struct dm_target_spec);
921 remaining = len - (outptr - outbuf);
922 if (remaining <= 0) {
923 param->flags |= DM_BUFFER_FULL_FLAG;
924 break;
925 }
926
927 /* Get the status/table string from the target driver */
928 if (ti->type->status) {
929 if (ti->type->status(ti, type, outptr, remaining)) {
930 param->flags |= DM_BUFFER_FULL_FLAG;
931 break;
932 }
933 } else
934 outptr[0] = '\0';
935
936 outptr += strlen(outptr) + 1;
937 used = param->data_start + (outptr - outbuf);
938
939 outptr = align_ptr(outptr);
940 spec->next = outptr - outbuf;
941 }
942
943 if (used)
944 param->data_size = used;
945
946 param->target_count = num_targets;
947 }
948
949 /*
950 * Wait for a device to report an event
951 */
952 static int dev_wait(struct dm_ioctl *param, size_t param_size)
953 {
954 int r;
955 struct mapped_device *md;
956 struct dm_table *table;
957
958 md = find_device(param);
959 if (!md)
960 return -ENXIO;
961
962 /*
963 * Wait for a notification event
964 */
965 if (dm_wait_event(md, param->event_nr)) {
966 r = -ERESTARTSYS;
967 goto out;
968 }
969
970 /*
971 * The userland program is going to want to know what
972 * changed to trigger the event, so we may as well tell
973 * him and save an ioctl.
974 */
975 r = __dev_status(md, param);
976 if (r)
977 goto out;
978
979 table = dm_get_table(md);
980 if (table) {
981 retrieve_status(table, param, param_size);
982 dm_table_put(table);
983 }
984
985 out:
986 dm_put(md);
987 return r;
988 }
989
990 static inline int get_mode(struct dm_ioctl *param)
991 {
992 int mode = FMODE_READ | FMODE_WRITE;
993
994 if (param->flags & DM_READONLY_FLAG)
995 mode = FMODE_READ;
996
997 return mode;
998 }
999
1000 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1001 struct dm_target_spec **spec, char **target_params)
1002 {
1003 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1004 *target_params = (char *) (*spec + 1);
1005
1006 if (*spec < (last + 1))
1007 return -EINVAL;
1008
1009 return invalid_str(*target_params, end);
1010 }
1011
1012 static int populate_table(struct dm_table *table,
1013 struct dm_ioctl *param, size_t param_size)
1014 {
1015 int r;
1016 unsigned int i = 0;
1017 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1018 uint32_t next = param->data_start;
1019 void *end = (void *) param + param_size;
1020 char *target_params;
1021
1022 if (!param->target_count) {
1023 DMWARN("populate_table: no targets specified");
1024 return -EINVAL;
1025 }
1026
1027 for (i = 0; i < param->target_count; i++) {
1028
1029 r = next_target(spec, next, end, &spec, &target_params);
1030 if (r) {
1031 DMWARN("unable to find target");
1032 return r;
1033 }
1034
1035 r = dm_table_add_target(table, spec->target_type,
1036 (sector_t) spec->sector_start,
1037 (sector_t) spec->length,
1038 target_params);
1039 if (r) {
1040 DMWARN("error adding target to table");
1041 return r;
1042 }
1043
1044 next = spec->next;
1045 }
1046
1047 return dm_table_complete(table);
1048 }
1049
1050 static int table_load(struct dm_ioctl *param, size_t param_size)
1051 {
1052 int r;
1053 struct hash_cell *hc;
1054 struct dm_table *t;
1055 struct mapped_device *md;
1056
1057 md = find_device(param);
1058 if (!md)
1059 return -ENXIO;
1060
1061 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1062 if (r)
1063 goto out;
1064
1065 r = populate_table(t, param, param_size);
1066 if (r) {
1067 dm_table_put(t);
1068 goto out;
1069 }
1070
1071 down_write(&_hash_lock);
1072 hc = dm_get_mdptr(md);
1073 if (!hc || hc->md != md) {
1074 DMWARN("device has been removed from the dev hash table.");
1075 dm_table_put(t);
1076 up_write(&_hash_lock);
1077 r = -ENXIO;
1078 goto out;
1079 }
1080
1081 if (hc->new_map)
1082 dm_table_put(hc->new_map);
1083 hc->new_map = t;
1084 up_write(&_hash_lock);
1085
1086 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1087 r = __dev_status(md, param);
1088
1089 out:
1090 dm_put(md);
1091
1092 return r;
1093 }
1094
1095 static int table_clear(struct dm_ioctl *param, size_t param_size)
1096 {
1097 int r;
1098 struct hash_cell *hc;
1099 struct mapped_device *md;
1100
1101 down_write(&_hash_lock);
1102
1103 hc = __find_device_hash_cell(param);
1104 if (!hc) {
1105 DMWARN("device doesn't appear to be in the dev hash table.");
1106 up_write(&_hash_lock);
1107 return -ENXIO;
1108 }
1109
1110 if (hc->new_map) {
1111 dm_table_put(hc->new_map);
1112 hc->new_map = NULL;
1113 }
1114
1115 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1116
1117 r = __dev_status(hc->md, param);
1118 md = hc->md;
1119 up_write(&_hash_lock);
1120 dm_put(md);
1121 return r;
1122 }
1123
1124 /*
1125 * Retrieves a list of devices used by a particular dm device.
1126 */
1127 static void retrieve_deps(struct dm_table *table,
1128 struct dm_ioctl *param, size_t param_size)
1129 {
1130 unsigned int count = 0;
1131 struct list_head *tmp;
1132 size_t len, needed;
1133 struct dm_dev *dd;
1134 struct dm_target_deps *deps;
1135
1136 deps = get_result_buffer(param, param_size, &len);
1137
1138 /*
1139 * Count the devices.
1140 */
1141 list_for_each (tmp, dm_table_get_devices(table))
1142 count++;
1143
1144 /*
1145 * Check we have enough space.
1146 */
1147 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1148 if (len < needed) {
1149 param->flags |= DM_BUFFER_FULL_FLAG;
1150 return;
1151 }
1152
1153 /*
1154 * Fill in the devices.
1155 */
1156 deps->count = count;
1157 count = 0;
1158 list_for_each_entry (dd, dm_table_get_devices(table), list)
1159 deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
1160
1161 param->data_size = param->data_start + needed;
1162 }
1163
1164 static int table_deps(struct dm_ioctl *param, size_t param_size)
1165 {
1166 int r = 0;
1167 struct mapped_device *md;
1168 struct dm_table *table;
1169
1170 md = find_device(param);
1171 if (!md)
1172 return -ENXIO;
1173
1174 r = __dev_status(md, param);
1175 if (r)
1176 goto out;
1177
1178 table = dm_get_table(md);
1179 if (table) {
1180 retrieve_deps(table, param, param_size);
1181 dm_table_put(table);
1182 }
1183
1184 out:
1185 dm_put(md);
1186 return r;
1187 }
1188
1189 /*
1190 * Return the status of a device as a text string for each
1191 * target.
1192 */
1193 static int table_status(struct dm_ioctl *param, size_t param_size)
1194 {
1195 int r;
1196 struct mapped_device *md;
1197 struct dm_table *table;
1198
1199 md = find_device(param);
1200 if (!md)
1201 return -ENXIO;
1202
1203 r = __dev_status(md, param);
1204 if (r)
1205 goto out;
1206
1207 table = dm_get_table(md);
1208 if (table) {
1209 retrieve_status(table, param, param_size);
1210 dm_table_put(table);
1211 }
1212
1213 out:
1214 dm_put(md);
1215 return r;
1216 }
1217
1218 /*
1219 * Pass a message to the target that's at the supplied device offset.
1220 */
1221 static int target_message(struct dm_ioctl *param, size_t param_size)
1222 {
1223 int r, argc;
1224 char **argv;
1225 struct mapped_device *md;
1226 struct dm_table *table;
1227 struct dm_target *ti;
1228 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1229
1230 md = find_device(param);
1231 if (!md)
1232 return -ENXIO;
1233
1234 r = __dev_status(md, param);
1235 if (r)
1236 goto out;
1237
1238 if (tmsg < (struct dm_target_msg *) param->data ||
1239 invalid_str(tmsg->message, (void *) param + param_size)) {
1240 DMWARN("Invalid target message parameters.");
1241 r = -EINVAL;
1242 goto out;
1243 }
1244
1245 r = dm_split_args(&argc, &argv, tmsg->message);
1246 if (r) {
1247 DMWARN("Failed to split target message parameters");
1248 goto out;
1249 }
1250
1251 table = dm_get_table(md);
1252 if (!table)
1253 goto out_argv;
1254
1255 ti = dm_table_find_target(table, tmsg->sector);
1256 if (!dm_target_is_valid(ti)) {
1257 DMWARN("Target message sector outside device.");
1258 r = -EINVAL;
1259 } else if (ti->type->message)
1260 r = ti->type->message(ti, argc, argv);
1261 else {
1262 DMWARN("Target type does not support messages");
1263 r = -EINVAL;
1264 }
1265
1266 dm_table_put(table);
1267 out_argv:
1268 kfree(argv);
1269 out:
1270 param->data_size = 0;
1271 dm_put(md);
1272 return r;
1273 }
1274
1275 /*-----------------------------------------------------------------
1276 * Implementation of open/close/ioctl on the special char
1277 * device.
1278 *---------------------------------------------------------------*/
1279 static ioctl_fn lookup_ioctl(unsigned int cmd)
1280 {
1281 static struct {
1282 int cmd;
1283 ioctl_fn fn;
1284 } _ioctls[] = {
1285 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1286 {DM_REMOVE_ALL_CMD, remove_all},
1287 {DM_LIST_DEVICES_CMD, list_devices},
1288
1289 {DM_DEV_CREATE_CMD, dev_create},
1290 {DM_DEV_REMOVE_CMD, dev_remove},
1291 {DM_DEV_RENAME_CMD, dev_rename},
1292 {DM_DEV_SUSPEND_CMD, dev_suspend},
1293 {DM_DEV_STATUS_CMD, dev_status},
1294 {DM_DEV_WAIT_CMD, dev_wait},
1295
1296 {DM_TABLE_LOAD_CMD, table_load},
1297 {DM_TABLE_CLEAR_CMD, table_clear},
1298 {DM_TABLE_DEPS_CMD, table_deps},
1299 {DM_TABLE_STATUS_CMD, table_status},
1300
1301 {DM_LIST_VERSIONS_CMD, list_versions},
1302
1303 {DM_TARGET_MSG_CMD, target_message},
1304 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1305 };
1306
1307 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1308 }
1309
1310 /*
1311 * As well as checking the version compatibility this always
1312 * copies the kernel interface version out.
1313 */
1314 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1315 {
1316 uint32_t version[3];
1317 int r = 0;
1318
1319 if (copy_from_user(version, user->version, sizeof(version)))
1320 return -EFAULT;
1321
1322 if ((DM_VERSION_MAJOR != version[0]) ||
1323 (DM_VERSION_MINOR < version[1])) {
1324 DMWARN("ioctl interface mismatch: "
1325 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1326 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1327 DM_VERSION_PATCHLEVEL,
1328 version[0], version[1], version[2], cmd);
1329 r = -EINVAL;
1330 }
1331
1332 /*
1333 * Fill in the kernel version.
1334 */
1335 version[0] = DM_VERSION_MAJOR;
1336 version[1] = DM_VERSION_MINOR;
1337 version[2] = DM_VERSION_PATCHLEVEL;
1338 if (copy_to_user(user->version, version, sizeof(version)))
1339 return -EFAULT;
1340
1341 return r;
1342 }
1343
1344 static void free_params(struct dm_ioctl *param)
1345 {
1346 vfree(param);
1347 }
1348
1349 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1350 {
1351 struct dm_ioctl tmp, *dmi;
1352
1353 if (copy_from_user(&tmp, user, sizeof(tmp)))
1354 return -EFAULT;
1355
1356 if (tmp.data_size < sizeof(tmp))
1357 return -EINVAL;
1358
1359 dmi = vmalloc(tmp.data_size);
1360 if (!dmi)
1361 return -ENOMEM;
1362
1363 if (copy_from_user(dmi, user, tmp.data_size)) {
1364 vfree(dmi);
1365 return -EFAULT;
1366 }
1367
1368 *param = dmi;
1369 return 0;
1370 }
1371
1372 static int validate_params(uint cmd, struct dm_ioctl *param)
1373 {
1374 /* Always clear this flag */
1375 param->flags &= ~DM_BUFFER_FULL_FLAG;
1376
1377 /* Ignores parameters */
1378 if (cmd == DM_REMOVE_ALL_CMD ||
1379 cmd == DM_LIST_DEVICES_CMD ||
1380 cmd == DM_LIST_VERSIONS_CMD)
1381 return 0;
1382
1383 if ((cmd == DM_DEV_CREATE_CMD)) {
1384 if (!*param->name) {
1385 DMWARN("name not supplied when creating device");
1386 return -EINVAL;
1387 }
1388 } else if ((*param->uuid && *param->name)) {
1389 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1390 return -EINVAL;
1391 }
1392
1393 /* Ensure strings are terminated */
1394 param->name[DM_NAME_LEN - 1] = '\0';
1395 param->uuid[DM_UUID_LEN - 1] = '\0';
1396
1397 return 0;
1398 }
1399
1400 static int ctl_ioctl(struct inode *inode, struct file *file,
1401 uint command, ulong u)
1402 {
1403 int r = 0;
1404 unsigned int cmd;
1405 struct dm_ioctl *param;
1406 struct dm_ioctl __user *user = (struct dm_ioctl __user *) u;
1407 ioctl_fn fn = NULL;
1408 size_t param_size;
1409
1410 /* only root can play with this */
1411 if (!capable(CAP_SYS_ADMIN))
1412 return -EACCES;
1413
1414 if (_IOC_TYPE(command) != DM_IOCTL)
1415 return -ENOTTY;
1416
1417 cmd = _IOC_NR(command);
1418
1419 /*
1420 * Check the interface version passed in. This also
1421 * writes out the kernel's interface version.
1422 */
1423 r = check_version(cmd, user);
1424 if (r)
1425 return r;
1426
1427 /*
1428 * Nothing more to do for the version command.
1429 */
1430 if (cmd == DM_VERSION_CMD)
1431 return 0;
1432
1433 fn = lookup_ioctl(cmd);
1434 if (!fn) {
1435 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1436 return -ENOTTY;
1437 }
1438
1439 /*
1440 * Trying to avoid low memory issues when a device is
1441 * suspended.
1442 */
1443 current->flags |= PF_MEMALLOC;
1444
1445 /*
1446 * Copy the parameters into kernel space.
1447 */
1448 r = copy_params(user, &param);
1449
1450 current->flags &= ~PF_MEMALLOC;
1451
1452 if (r)
1453 return r;
1454
1455 r = validate_params(cmd, param);
1456 if (r)
1457 goto out;
1458
1459 param_size = param->data_size;
1460 param->data_size = sizeof(*param);
1461 r = fn(param, param_size);
1462
1463 /*
1464 * Copy the results back to userland.
1465 */
1466 if (!r && copy_to_user(user, param, param->data_size))
1467 r = -EFAULT;
1468
1469 out:
1470 free_params(param);
1471 return r;
1472 }
1473
1474 static const struct file_operations _ctl_fops = {
1475 .ioctl = ctl_ioctl,
1476 .owner = THIS_MODULE,
1477 };
1478
1479 static struct miscdevice _dm_misc = {
1480 .minor = MISC_DYNAMIC_MINOR,
1481 .name = DM_NAME,
1482 .fops = &_ctl_fops
1483 };
1484
1485 /*
1486 * Create misc character device and link to DM_DIR/control.
1487 */
1488 int __init dm_interface_init(void)
1489 {
1490 int r;
1491
1492 r = dm_hash_init();
1493 if (r)
1494 return r;
1495
1496 r = misc_register(&_dm_misc);
1497 if (r) {
1498 DMERR("misc_register failed for control device");
1499 dm_hash_exit();
1500 return r;
1501 }
1502
1503 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1504 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1505 DM_DRIVER_EMAIL);
1506 return 0;
1507 }
1508
1509 void dm_interface_exit(void)
1510 {
1511 if (misc_deregister(&_dm_misc) < 0)
1512 DMERR("misc_deregister failed for control device");
1513
1514 dm_hash_exit();
1515 }
1516
1517 /**
1518 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1519 * @md: Pointer to mapped_device
1520 * @name: Buffer (size DM_NAME_LEN) for name
1521 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1522 */
1523 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1524 {
1525 int r = 0;
1526 struct hash_cell *hc;
1527
1528 if (!md)
1529 return -ENXIO;
1530
1531 dm_get(md);
1532 down_read(&_hash_lock);
1533 hc = dm_get_mdptr(md);
1534 if (!hc || hc->md != md) {
1535 r = -ENXIO;
1536 goto out;
1537 }
1538
1539 strcpy(name, hc->name);
1540 strcpy(uuid, hc->uuid ? : "");
1541
1542 out:
1543 up_read(&_hash_lock);
1544 dm_put(md);
1545
1546 return r;
1547 }
WRT350N Kernel Patches