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ACPI: pci_root: simplify list traversals
[linux-2.6/linux-acpi-2.6.git] / drivers / md / dm-ioctl.c
blob823ceba6efa8dcccc95b14cf72986195c52b3ae8
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 #include <linux/compat.h>
19
20 #include <asm/uaccess.h>
21
22 #define DM_MSG_PREFIX "ioctl"
23 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
24
25 /*-----------------------------------------------------------------
26 * The ioctl interface needs to be able to look up devices by
27 * name or uuid.
28 *---------------------------------------------------------------*/
29 struct hash_cell {
30 struct list_head name_list;
31 struct list_head uuid_list;
32
33 char *name;
34 char *uuid;
35 struct mapped_device *md;
36 struct dm_table *new_map;
37 };
38
39 struct vers_iter {
40 size_t param_size;
41 struct dm_target_versions *vers, *old_vers;
42 char *end;
43 uint32_t flags;
44 };
45
46
47 #define NUM_BUCKETS 64
48 #define MASK_BUCKETS (NUM_BUCKETS - 1)
49 static struct list_head _name_buckets[NUM_BUCKETS];
50 static struct list_head _uuid_buckets[NUM_BUCKETS];
51
52 static void dm_hash_remove_all(int keep_open_devices);
53
54 /*
55 * Guards access to both hash tables.
56 */
57 static DECLARE_RWSEM(_hash_lock);
58
59 static void init_buckets(struct list_head *buckets)
60 {
61 unsigned int i;
62
63 for (i = 0; i < NUM_BUCKETS; i++)
64 INIT_LIST_HEAD(buckets + i);
65 }
66
67 static int dm_hash_init(void)
68 {
69 init_buckets(_name_buckets);
70 init_buckets(_uuid_buckets);
71 return 0;
72 }
73
74 static void dm_hash_exit(void)
75 {
76 dm_hash_remove_all(0);
77 }
78
79 /*-----------------------------------------------------------------
80 * Hash function:
81 * We're not really concerned with the str hash function being
82 * fast since it's only used by the ioctl interface.
83 *---------------------------------------------------------------*/
84 static unsigned int hash_str(const char *str)
85 {
86 const unsigned int hash_mult = 2654435387U;
87 unsigned int h = 0;
88
89 while (*str)
90 h = (h + (unsigned int) *str++) * hash_mult;
91
92 return h & MASK_BUCKETS;
93 }
94
95 /*-----------------------------------------------------------------
96 * Code for looking up a device by name
97 *---------------------------------------------------------------*/
98 static struct hash_cell *__get_name_cell(const char *str)
99 {
100 struct hash_cell *hc;
101 unsigned int h = hash_str(str);
102
103 list_for_each_entry (hc, _name_buckets + h, name_list)
104 if (!strcmp(hc->name, str)) {
105 dm_get(hc->md);
106 return hc;
107 }
108
109 return NULL;
110 }
111
112 static struct hash_cell *__get_uuid_cell(const char *str)
113 {
114 struct hash_cell *hc;
115 unsigned int h = hash_str(str);
116
117 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
118 if (!strcmp(hc->uuid, str)) {
119 dm_get(hc->md);
120 return hc;
121 }
122
123 return NULL;
124 }
125
126 /*-----------------------------------------------------------------
127 * Inserting, removing and renaming a device.
128 *---------------------------------------------------------------*/
129 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
130 struct mapped_device *md)
131 {
132 struct hash_cell *hc;
133
134 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
135 if (!hc)
136 return NULL;
137
138 hc->name = kstrdup(name, GFP_KERNEL);
139 if (!hc->name) {
140 kfree(hc);
141 return NULL;
142 }
143
144 if (!uuid)
145 hc->uuid = NULL;
146
147 else {
148 hc->uuid = kstrdup(uuid, GFP_KERNEL);
149 if (!hc->uuid) {
150 kfree(hc->name);
151 kfree(hc);
152 return NULL;
153 }
154 }
155
156 INIT_LIST_HEAD(&hc->name_list);
157 INIT_LIST_HEAD(&hc->uuid_list);
158 hc->md = md;
159 hc->new_map = NULL;
160 return hc;
161 }
162
163 static void free_cell(struct hash_cell *hc)
164 {
165 if (hc) {
166 kfree(hc->name);
167 kfree(hc->uuid);
168 kfree(hc);
169 }
170 }
171
172 /*
173 * The kdev_t and uuid of a device can never change once it is
174 * initially inserted.
175 */
176 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
177 {
178 struct hash_cell *cell, *hc;
179
180 /*
181 * Allocate the new cells.
182 */
183 cell = alloc_cell(name, uuid, md);
184 if (!cell)
185 return -ENOMEM;
186
187 /*
188 * Insert the cell into both hash tables.
189 */
190 down_write(&_hash_lock);
191 hc = __get_name_cell(name);
192 if (hc) {
193 dm_put(hc->md);
194 goto bad;
195 }
196
197 list_add(&cell->name_list, _name_buckets + hash_str(name));
198
199 if (uuid) {
200 hc = __get_uuid_cell(uuid);
201 if (hc) {
202 list_del(&cell->name_list);
203 dm_put(hc->md);
204 goto bad;
205 }
206 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
207 }
208 dm_get(md);
209 dm_set_mdptr(md, cell);
210 up_write(&_hash_lock);
211
212 return 0;
213
214 bad:
215 up_write(&_hash_lock);
216 free_cell(cell);
217 return -EBUSY;
218 }
219
220 static void __hash_remove(struct hash_cell *hc)
221 {
222 struct dm_table *table;
223
224 /* remove from the dev hash */
225 list_del(&hc->uuid_list);
226 list_del(&hc->name_list);
227 dm_set_mdptr(hc->md, NULL);
228
229 table = dm_get_table(hc->md);
230 if (table) {
231 dm_table_event(table);
232 dm_table_put(table);
233 }
234
235 if (hc->new_map)
236 dm_table_destroy(hc->new_map);
237 dm_put(hc->md);
238 free_cell(hc);
239 }
240
241 static void dm_hash_remove_all(int keep_open_devices)
242 {
243 int i, dev_skipped, dev_removed;
244 struct hash_cell *hc;
245 struct list_head *tmp, *n;
246
247 down_write(&_hash_lock);
248
249 retry:
250 dev_skipped = dev_removed = 0;
251 for (i = 0; i < NUM_BUCKETS; i++) {
252 list_for_each_safe (tmp, n, _name_buckets + i) {
253 hc = list_entry(tmp, struct hash_cell, name_list);
254
255 if (keep_open_devices &&
256 dm_lock_for_deletion(hc->md)) {
257 dev_skipped++;
258 continue;
259 }
260 __hash_remove(hc);
261 dev_removed = 1;
262 }
263 }
264
265 /*
266 * Some mapped devices may be using other mapped devices, so if any
267 * still exist, repeat until we make no further progress.
268 */
269 if (dev_skipped) {
270 if (dev_removed)
271 goto retry;
272
273 DMWARN("remove_all left %d open device(s)", dev_skipped);
274 }
275
276 up_write(&_hash_lock);
277 }
278
279 static int dm_hash_rename(const char *old, const char *new)
280 {
281 char *new_name, *old_name;
282 struct hash_cell *hc;
283 struct dm_table *table;
284
285 /*
286 * duplicate new.
287 */
288 new_name = kstrdup(new, GFP_KERNEL);
289 if (!new_name)
290 return -ENOMEM;
291
292 down_write(&_hash_lock);
293
294 /*
295 * Is new free ?
296 */
297 hc = __get_name_cell(new);
298 if (hc) {
299 DMWARN("asked to rename to an already existing name %s -> %s",
300 old, new);
301 dm_put(hc->md);
302 up_write(&_hash_lock);
303 kfree(new_name);
304 return -EBUSY;
305 }
306
307 /*
308 * Is there such a device as 'old' ?
309 */
310 hc = __get_name_cell(old);
311 if (!hc) {
312 DMWARN("asked to rename a non existent device %s -> %s",
313 old, new);
314 up_write(&_hash_lock);
315 kfree(new_name);
316 return -ENXIO;
317 }
318
319 /*
320 * rename and move the name cell.
321 */
322 list_del(&hc->name_list);
323 old_name = hc->name;
324 hc->name = new_name;
325 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
326
327 /*
328 * Wake up any dm event waiters.
329 */
330 table = dm_get_table(hc->md);
331 if (table) {
332 dm_table_event(table);
333 dm_table_put(table);
334 }
335
336 dm_kobject_uevent(hc->md);
337
338 dm_put(hc->md);
339 up_write(&_hash_lock);
340 kfree(old_name);
341 return 0;
342 }
343
344 /*-----------------------------------------------------------------
345 * Implementation of the ioctl commands
346 *---------------------------------------------------------------*/
347 /*
348 * All the ioctl commands get dispatched to functions with this
349 * prototype.
350 */
351 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
352
353 static int remove_all(struct dm_ioctl *param, size_t param_size)
354 {
355 dm_hash_remove_all(1);
356 param->data_size = 0;
357 return 0;
358 }
359
360 /*
361 * Round up the ptr to an 8-byte boundary.
362 */
363 #define ALIGN_MASK 7
364 static inline void *align_ptr(void *ptr)
365 {
366 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
367 }
368
369 /*
370 * Retrieves the data payload buffer from an already allocated
371 * struct dm_ioctl.
372 */
373 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
374 size_t *len)
375 {
376 param->data_start = align_ptr(param + 1) - (void *) param;
377
378 if (param->data_start < param_size)
379 *len = param_size - param->data_start;
380 else
381 *len = 0;
382
383 return ((void *) param) + param->data_start;
384 }
385
386 static int list_devices(struct dm_ioctl *param, size_t param_size)
387 {
388 unsigned int i;
389 struct hash_cell *hc;
390 size_t len, needed = 0;
391 struct gendisk *disk;
392 struct dm_name_list *nl, *old_nl = NULL;
393
394 down_write(&_hash_lock);
395
396 /*
397 * Loop through all the devices working out how much
398 * space we need.
399 */
400 for (i = 0; i < NUM_BUCKETS; i++) {
401 list_for_each_entry (hc, _name_buckets + i, name_list) {
402 needed += sizeof(struct dm_name_list);
403 needed += strlen(hc->name) + 1;
404 needed += ALIGN_MASK;
405 }
406 }
407
408 /*
409 * Grab our output buffer.
410 */
411 nl = get_result_buffer(param, param_size, &len);
412 if (len < needed) {
413 param->flags |= DM_BUFFER_FULL_FLAG;
414 goto out;
415 }
416 param->data_size = param->data_start + needed;
417
418 nl->dev = 0; /* Flags no data */
419
420 /*
421 * Now loop through filling out the names.
422 */
423 for (i = 0; i < NUM_BUCKETS; i++) {
424 list_for_each_entry (hc, _name_buckets + i, name_list) {
425 if (old_nl)
426 old_nl->next = (uint32_t) ((void *) nl -
427 (void *) old_nl);
428 disk = dm_disk(hc->md);
429 nl->dev = huge_encode_dev(disk_devt(disk));
430 nl->next = 0;
431 strcpy(nl->name, hc->name);
432
433 old_nl = nl;
434 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
435 }
436 }
437
438 out:
439 up_write(&_hash_lock);
440 return 0;
441 }
442
443 static void list_version_get_needed(struct target_type *tt, void *needed_param)
444 {
445 size_t *needed = needed_param;
446
447 *needed += sizeof(struct dm_target_versions);
448 *needed += strlen(tt->name);
449 *needed += ALIGN_MASK;
450 }
451
452 static void list_version_get_info(struct target_type *tt, void *param)
453 {
454 struct vers_iter *info = param;
455
456 /* Check space - it might have changed since the first iteration */
457 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
458 info->end) {
459
460 info->flags = DM_BUFFER_FULL_FLAG;
461 return;
462 }
463
464 if (info->old_vers)
465 info->old_vers->next = (uint32_t) ((void *)info->vers -
466 (void *)info->old_vers);
467 info->vers->version[0] = tt->version[0];
468 info->vers->version[1] = tt->version[1];
469 info->vers->version[2] = tt->version[2];
470 info->vers->next = 0;
471 strcpy(info->vers->name, tt->name);
472
473 info->old_vers = info->vers;
474 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
475 }
476
477 static int list_versions(struct dm_ioctl *param, size_t param_size)
478 {
479 size_t len, needed = 0;
480 struct dm_target_versions *vers;
481 struct vers_iter iter_info;
482
483 /*
484 * Loop through all the devices working out how much
485 * space we need.
486 */
487 dm_target_iterate(list_version_get_needed, &needed);
488
489 /*
490 * Grab our output buffer.
491 */
492 vers = get_result_buffer(param, param_size, &len);
493 if (len < needed) {
494 param->flags |= DM_BUFFER_FULL_FLAG;
495 goto out;
496 }
497 param->data_size = param->data_start + needed;
498
499 iter_info.param_size = param_size;
500 iter_info.old_vers = NULL;
501 iter_info.vers = vers;
502 iter_info.flags = 0;
503 iter_info.end = (char *)vers+len;
504
505 /*
506 * Now loop through filling out the names & versions.
507 */
508 dm_target_iterate(list_version_get_info, &iter_info);
509 param->flags |= iter_info.flags;
510
511 out:
512 return 0;
513 }
514
515
516
517 static int check_name(const char *name)
518 {
519 if (strchr(name, '/')) {
520 DMWARN("invalid device name");
521 return -EINVAL;
522 }
523
524 return 0;
525 }
526
527 /*
528 * Fills in a dm_ioctl structure, ready for sending back to
529 * userland.
530 */
531 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
532 {
533 struct gendisk *disk = dm_disk(md);
534 struct dm_table *table;
535
536 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
537 DM_ACTIVE_PRESENT_FLAG);
538
539 if (dm_suspended(md))
540 param->flags |= DM_SUSPEND_FLAG;
541
542 param->dev = huge_encode_dev(disk_devt(disk));
543
544 /*
545 * Yes, this will be out of date by the time it gets back
546 * to userland, but it is still very useful for
547 * debugging.
548 */
549 param->open_count = dm_open_count(md);
550
551 if (get_disk_ro(disk))
552 param->flags |= DM_READONLY_FLAG;
553
554 param->event_nr = dm_get_event_nr(md);
555
556 table = dm_get_table(md);
557 if (table) {
558 param->flags |= DM_ACTIVE_PRESENT_FLAG;
559 param->target_count = dm_table_get_num_targets(table);
560 dm_table_put(table);
561 } else
562 param->target_count = 0;
563
564 return 0;
565 }
566
567 static int dev_create(struct dm_ioctl *param, size_t param_size)
568 {
569 int r, m = DM_ANY_MINOR;
570 struct mapped_device *md;
571
572 r = check_name(param->name);
573 if (r)
574 return r;
575
576 if (param->flags & DM_PERSISTENT_DEV_FLAG)
577 m = MINOR(huge_decode_dev(param->dev));
578
579 r = dm_create(m, &md);
580 if (r)
581 return r;
582
583 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
584 if (r) {
585 dm_put(md);
586 return r;
587 }
588
589 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
590
591 r = __dev_status(md, param);
592 dm_put(md);
593
594 return r;
595 }
596
597 /*
598 * Always use UUID for lookups if it's present, otherwise use name or dev.
599 */
600 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
601 {
602 struct mapped_device *md;
603 void *mdptr = NULL;
604
605 if (*param->uuid)
606 return __get_uuid_cell(param->uuid);
607
608 if (*param->name)
609 return __get_name_cell(param->name);
610
611 md = dm_get_md(huge_decode_dev(param->dev));
612 if (!md)
613 goto out;
614
615 mdptr = dm_get_mdptr(md);
616 if (!mdptr)
617 dm_put(md);
618
619 out:
620 return mdptr;
621 }
622
623 static struct mapped_device *find_device(struct dm_ioctl *param)
624 {
625 struct hash_cell *hc;
626 struct mapped_device *md = NULL;
627
628 down_read(&_hash_lock);
629 hc = __find_device_hash_cell(param);
630 if (hc) {
631 md = hc->md;
632
633 /*
634 * Sneakily write in both the name and the uuid
635 * while we have the cell.
636 */
637 strncpy(param->name, hc->name, sizeof(param->name));
638 if (hc->uuid)
639 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
640 else
641 param->uuid[0] = '\0';
642
643 if (hc->new_map)
644 param->flags |= DM_INACTIVE_PRESENT_FLAG;
645 else
646 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
647 }
648 up_read(&_hash_lock);
649
650 return md;
651 }
652
653 static int dev_remove(struct dm_ioctl *param, size_t param_size)
654 {
655 struct hash_cell *hc;
656 struct mapped_device *md;
657 int r;
658
659 down_write(&_hash_lock);
660 hc = __find_device_hash_cell(param);
661
662 if (!hc) {
663 DMWARN("device doesn't appear to be in the dev hash table.");
664 up_write(&_hash_lock);
665 return -ENXIO;
666 }
667
668 md = hc->md;
669
670 /*
671 * Ensure the device is not open and nothing further can open it.
672 */
673 r = dm_lock_for_deletion(md);
674 if (r) {
675 DMWARN("unable to remove open device %s", hc->name);
676 up_write(&_hash_lock);
677 dm_put(md);
678 return r;
679 }
680
681 __hash_remove(hc);
682 up_write(&_hash_lock);
683 dm_put(md);
684 param->data_size = 0;
685 return 0;
686 }
687
688 /*
689 * Check a string doesn't overrun the chunk of
690 * memory we copied from userland.
691 */
692 static int invalid_str(char *str, void *end)
693 {
694 while ((void *) str < end)
695 if (!*str++)
696 return 0;
697
698 return -EINVAL;
699 }
700
701 static int dev_rename(struct dm_ioctl *param, size_t param_size)
702 {
703 int r;
704 char *new_name = (char *) param + param->data_start;
705
706 if (new_name < param->data ||
707 invalid_str(new_name, (void *) param + param_size) ||
708 strlen(new_name) > DM_NAME_LEN - 1) {
709 DMWARN("Invalid new logical volume name supplied.");
710 return -EINVAL;
711 }
712
713 r = check_name(new_name);
714 if (r)
715 return r;
716
717 param->data_size = 0;
718 return dm_hash_rename(param->name, new_name);
719 }
720
721 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
722 {
723 int r = -EINVAL, x;
724 struct mapped_device *md;
725 struct hd_geometry geometry;
726 unsigned long indata[4];
727 char *geostr = (char *) param + param->data_start;
728
729 md = find_device(param);
730 if (!md)
731 return -ENXIO;
732
733 if (geostr < param->data ||
734 invalid_str(geostr, (void *) param + param_size)) {
735 DMWARN("Invalid geometry supplied.");
736 goto out;
737 }
738
739 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
740 indata + 1, indata + 2, indata + 3);
741
742 if (x != 4) {
743 DMWARN("Unable to interpret geometry settings.");
744 goto out;
745 }
746
747 if (indata[0] > 65535 || indata[1] > 255 ||
748 indata[2] > 255 || indata[3] > ULONG_MAX) {
749 DMWARN("Geometry exceeds range limits.");
750 goto out;
751 }
752
753 geometry.cylinders = indata[0];
754 geometry.heads = indata[1];
755 geometry.sectors = indata[2];
756 geometry.start = indata[3];
757
758 r = dm_set_geometry(md, &geometry);
759 if (!r)
760 r = __dev_status(md, param);
761
762 param->data_size = 0;
763
764 out:
765 dm_put(md);
766 return r;
767 }
768
769 static int do_suspend(struct dm_ioctl *param)
770 {
771 int r = 0;
772 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
773 struct mapped_device *md;
774
775 md = find_device(param);
776 if (!md)
777 return -ENXIO;
778
779 if (param->flags & DM_SKIP_LOCKFS_FLAG)
780 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
781 if (param->flags & DM_NOFLUSH_FLAG)
782 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
783
784 if (!dm_suspended(md))
785 r = dm_suspend(md, suspend_flags);
786
787 if (!r)
788 r = __dev_status(md, param);
789
790 dm_put(md);
791 return r;
792 }
793
794 static int do_resume(struct dm_ioctl *param)
795 {
796 int r = 0;
797 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
798 struct hash_cell *hc;
799 struct mapped_device *md;
800 struct dm_table *new_map;
801
802 down_write(&_hash_lock);
803
804 hc = __find_device_hash_cell(param);
805 if (!hc) {
806 DMWARN("device doesn't appear to be in the dev hash table.");
807 up_write(&_hash_lock);
808 return -ENXIO;
809 }
810
811 md = hc->md;
812
813 new_map = hc->new_map;
814 hc->new_map = NULL;
815 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
816
817 up_write(&_hash_lock);
818
819 /* Do we need to load a new map ? */
820 if (new_map) {
821 /* Suspend if it isn't already suspended */
822 if (param->flags & DM_SKIP_LOCKFS_FLAG)
823 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
824 if (param->flags & DM_NOFLUSH_FLAG)
825 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
826 if (!dm_suspended(md))
827 dm_suspend(md, suspend_flags);
828
829 r = dm_swap_table(md, new_map);
830 if (r) {
831 dm_table_destroy(new_map);
832 dm_put(md);
833 return r;
834 }
835
836 if (dm_table_get_mode(new_map) & FMODE_WRITE)
837 set_disk_ro(dm_disk(md), 0);
838 else
839 set_disk_ro(dm_disk(md), 1);
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 fmode_t get_mode(struct dm_ioctl *param)
991 {
992 fmode_t 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_prealloc_integrity(struct dm_table *t,
1051 struct mapped_device *md)
1052 {
1053 struct list_head *devices = dm_table_get_devices(t);
1054 struct dm_dev_internal *dd;
1055
1056 list_for_each_entry(dd, devices, list)
1057 if (bdev_get_integrity(dd->dm_dev.bdev))
1058 return blk_integrity_register(dm_disk(md), NULL);
1059
1060 return 0;
1061 }
1062
1063 static int table_load(struct dm_ioctl *param, size_t param_size)
1064 {
1065 int r;
1066 struct hash_cell *hc;
1067 struct dm_table *t;
1068 struct mapped_device *md;
1069
1070 md = find_device(param);
1071 if (!md)
1072 return -ENXIO;
1073
1074 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1075 if (r)
1076 goto out;
1077
1078 r = populate_table(t, param, param_size);
1079 if (r) {
1080 dm_table_destroy(t);
1081 goto out;
1082 }
1083
1084 r = table_prealloc_integrity(t, md);
1085 if (r) {
1086 DMERR("%s: could not register integrity profile.",
1087 dm_device_name(md));
1088 dm_table_destroy(t);
1089 goto out;
1090 }
1091
1092 down_write(&_hash_lock);
1093 hc = dm_get_mdptr(md);
1094 if (!hc || hc->md != md) {
1095 DMWARN("device has been removed from the dev hash table.");
1096 dm_table_destroy(t);
1097 up_write(&_hash_lock);
1098 r = -ENXIO;
1099 goto out;
1100 }
1101
1102 if (hc->new_map)
1103 dm_table_destroy(hc->new_map);
1104 hc->new_map = t;
1105 up_write(&_hash_lock);
1106
1107 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1108 r = __dev_status(md, param);
1109
1110 out:
1111 dm_put(md);
1112
1113 return r;
1114 }
1115
1116 static int table_clear(struct dm_ioctl *param, size_t param_size)
1117 {
1118 int r;
1119 struct hash_cell *hc;
1120 struct mapped_device *md;
1121
1122 down_write(&_hash_lock);
1123
1124 hc = __find_device_hash_cell(param);
1125 if (!hc) {
1126 DMWARN("device doesn't appear to be in the dev hash table.");
1127 up_write(&_hash_lock);
1128 return -ENXIO;
1129 }
1130
1131 if (hc->new_map) {
1132 dm_table_destroy(hc->new_map);
1133 hc->new_map = NULL;
1134 }
1135
1136 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1137
1138 r = __dev_status(hc->md, param);
1139 md = hc->md;
1140 up_write(&_hash_lock);
1141 dm_put(md);
1142 return r;
1143 }
1144
1145 /*
1146 * Retrieves a list of devices used by a particular dm device.
1147 */
1148 static void retrieve_deps(struct dm_table *table,
1149 struct dm_ioctl *param, size_t param_size)
1150 {
1151 unsigned int count = 0;
1152 struct list_head *tmp;
1153 size_t len, needed;
1154 struct dm_dev_internal *dd;
1155 struct dm_target_deps *deps;
1156
1157 deps = get_result_buffer(param, param_size, &len);
1158
1159 /*
1160 * Count the devices.
1161 */
1162 list_for_each (tmp, dm_table_get_devices(table))
1163 count++;
1164
1165 /*
1166 * Check we have enough space.
1167 */
1168 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1169 if (len < needed) {
1170 param->flags |= DM_BUFFER_FULL_FLAG;
1171 return;
1172 }
1173
1174 /*
1175 * Fill in the devices.
1176 */
1177 deps->count = count;
1178 count = 0;
1179 list_for_each_entry (dd, dm_table_get_devices(table), list)
1180 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1181
1182 param->data_size = param->data_start + needed;
1183 }
1184
1185 static int table_deps(struct dm_ioctl *param, size_t param_size)
1186 {
1187 int r = 0;
1188 struct mapped_device *md;
1189 struct dm_table *table;
1190
1191 md = find_device(param);
1192 if (!md)
1193 return -ENXIO;
1194
1195 r = __dev_status(md, param);
1196 if (r)
1197 goto out;
1198
1199 table = dm_get_table(md);
1200 if (table) {
1201 retrieve_deps(table, param, param_size);
1202 dm_table_put(table);
1203 }
1204
1205 out:
1206 dm_put(md);
1207 return r;
1208 }
1209
1210 /*
1211 * Return the status of a device as a text string for each
1212 * target.
1213 */
1214 static int table_status(struct dm_ioctl *param, size_t param_size)
1215 {
1216 int r;
1217 struct mapped_device *md;
1218 struct dm_table *table;
1219
1220 md = find_device(param);
1221 if (!md)
1222 return -ENXIO;
1223
1224 r = __dev_status(md, param);
1225 if (r)
1226 goto out;
1227
1228 table = dm_get_table(md);
1229 if (table) {
1230 retrieve_status(table, param, param_size);
1231 dm_table_put(table);
1232 }
1233
1234 out:
1235 dm_put(md);
1236 return r;
1237 }
1238
1239 /*
1240 * Pass a message to the target that's at the supplied device offset.
1241 */
1242 static int target_message(struct dm_ioctl *param, size_t param_size)
1243 {
1244 int r, argc;
1245 char **argv;
1246 struct mapped_device *md;
1247 struct dm_table *table;
1248 struct dm_target *ti;
1249 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1250
1251 md = find_device(param);
1252 if (!md)
1253 return -ENXIO;
1254
1255 r = __dev_status(md, param);
1256 if (r)
1257 goto out;
1258
1259 if (tmsg < (struct dm_target_msg *) param->data ||
1260 invalid_str(tmsg->message, (void *) param + param_size)) {
1261 DMWARN("Invalid target message parameters.");
1262 r = -EINVAL;
1263 goto out;
1264 }
1265
1266 r = dm_split_args(&argc, &argv, tmsg->message);
1267 if (r) {
1268 DMWARN("Failed to split target message parameters");
1269 goto out;
1270 }
1271
1272 table = dm_get_table(md);
1273 if (!table)
1274 goto out_argv;
1275
1276 ti = dm_table_find_target(table, tmsg->sector);
1277 if (!dm_target_is_valid(ti)) {
1278 DMWARN("Target message sector outside device.");
1279 r = -EINVAL;
1280 } else if (ti->type->message)
1281 r = ti->type->message(ti, argc, argv);
1282 else {
1283 DMWARN("Target type does not support messages");
1284 r = -EINVAL;
1285 }
1286
1287 dm_table_put(table);
1288 out_argv:
1289 kfree(argv);
1290 out:
1291 param->data_size = 0;
1292 dm_put(md);
1293 return r;
1294 }
1295
1296 /*-----------------------------------------------------------------
1297 * Implementation of open/close/ioctl on the special char
1298 * device.
1299 *---------------------------------------------------------------*/
1300 static ioctl_fn lookup_ioctl(unsigned int cmd)
1301 {
1302 static struct {
1303 int cmd;
1304 ioctl_fn fn;
1305 } _ioctls[] = {
1306 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1307 {DM_REMOVE_ALL_CMD, remove_all},
1308 {DM_LIST_DEVICES_CMD, list_devices},
1309
1310 {DM_DEV_CREATE_CMD, dev_create},
1311 {DM_DEV_REMOVE_CMD, dev_remove},
1312 {DM_DEV_RENAME_CMD, dev_rename},
1313 {DM_DEV_SUSPEND_CMD, dev_suspend},
1314 {DM_DEV_STATUS_CMD, dev_status},
1315 {DM_DEV_WAIT_CMD, dev_wait},
1316
1317 {DM_TABLE_LOAD_CMD, table_load},
1318 {DM_TABLE_CLEAR_CMD, table_clear},
1319 {DM_TABLE_DEPS_CMD, table_deps},
1320 {DM_TABLE_STATUS_CMD, table_status},
1321
1322 {DM_LIST_VERSIONS_CMD, list_versions},
1323
1324 {DM_TARGET_MSG_CMD, target_message},
1325 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1326 };
1327
1328 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1329 }
1330
1331 /*
1332 * As well as checking the version compatibility this always
1333 * copies the kernel interface version out.
1334 */
1335 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1336 {
1337 uint32_t version[3];
1338 int r = 0;
1339
1340 if (copy_from_user(version, user->version, sizeof(version)))
1341 return -EFAULT;
1342
1343 if ((DM_VERSION_MAJOR != version[0]) ||
1344 (DM_VERSION_MINOR < version[1])) {
1345 DMWARN("ioctl interface mismatch: "
1346 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1347 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1348 DM_VERSION_PATCHLEVEL,
1349 version[0], version[1], version[2], cmd);
1350 r = -EINVAL;
1351 }
1352
1353 /*
1354 * Fill in the kernel version.
1355 */
1356 version[0] = DM_VERSION_MAJOR;
1357 version[1] = DM_VERSION_MINOR;
1358 version[2] = DM_VERSION_PATCHLEVEL;
1359 if (copy_to_user(user->version, version, sizeof(version)))
1360 return -EFAULT;
1361
1362 return r;
1363 }
1364
1365 static void free_params(struct dm_ioctl *param)
1366 {
1367 vfree(param);
1368 }
1369
1370 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1371 {
1372 struct dm_ioctl tmp, *dmi;
1373
1374 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1375 return -EFAULT;
1376
1377 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1378 return -EINVAL;
1379
1380 dmi = vmalloc(tmp.data_size);
1381 if (!dmi)
1382 return -ENOMEM;
1383
1384 if (copy_from_user(dmi, user, tmp.data_size)) {
1385 vfree(dmi);
1386 return -EFAULT;
1387 }
1388
1389 *param = dmi;
1390 return 0;
1391 }
1392
1393 static int validate_params(uint cmd, struct dm_ioctl *param)
1394 {
1395 /* Always clear this flag */
1396 param->flags &= ~DM_BUFFER_FULL_FLAG;
1397
1398 /* Ignores parameters */
1399 if (cmd == DM_REMOVE_ALL_CMD ||
1400 cmd == DM_LIST_DEVICES_CMD ||
1401 cmd == DM_LIST_VERSIONS_CMD)
1402 return 0;
1403
1404 if ((cmd == DM_DEV_CREATE_CMD)) {
1405 if (!*param->name) {
1406 DMWARN("name not supplied when creating device");
1407 return -EINVAL;
1408 }
1409 } else if ((*param->uuid && *param->name)) {
1410 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1411 return -EINVAL;
1412 }
1413
1414 /* Ensure strings are terminated */
1415 param->name[DM_NAME_LEN - 1] = '\0';
1416 param->uuid[DM_UUID_LEN - 1] = '\0';
1417
1418 return 0;
1419 }
1420
1421 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1422 {
1423 int r = 0;
1424 unsigned int cmd;
1425 struct dm_ioctl *uninitialized_var(param);
1426 ioctl_fn fn = NULL;
1427 size_t param_size;
1428
1429 /* only root can play with this */
1430 if (!capable(CAP_SYS_ADMIN))
1431 return -EACCES;
1432
1433 if (_IOC_TYPE(command) != DM_IOCTL)
1434 return -ENOTTY;
1435
1436 cmd = _IOC_NR(command);
1437
1438 /*
1439 * Check the interface version passed in. This also
1440 * writes out the kernel's interface version.
1441 */
1442 r = check_version(cmd, user);
1443 if (r)
1444 return r;
1445
1446 /*
1447 * Nothing more to do for the version command.
1448 */
1449 if (cmd == DM_VERSION_CMD)
1450 return 0;
1451
1452 fn = lookup_ioctl(cmd);
1453 if (!fn) {
1454 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1455 return -ENOTTY;
1456 }
1457
1458 /*
1459 * Trying to avoid low memory issues when a device is
1460 * suspended.
1461 */
1462 current->flags |= PF_MEMALLOC;
1463
1464 /*
1465 * Copy the parameters into kernel space.
1466 */
1467 r = copy_params(user, &param);
1468
1469 current->flags &= ~PF_MEMALLOC;
1470
1471 if (r)
1472 return r;
1473
1474 r = validate_params(cmd, param);
1475 if (r)
1476 goto out;
1477
1478 param_size = param->data_size;
1479 param->data_size = sizeof(*param);
1480 r = fn(param, param_size);
1481
1482 /*
1483 * Copy the results back to userland.
1484 */
1485 if (!r && copy_to_user(user, param, param->data_size))
1486 r = -EFAULT;
1487
1488 out:
1489 free_params(param);
1490 return r;
1491 }
1492
1493 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1494 {
1495 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1496 }
1497
1498 #ifdef CONFIG_COMPAT
1499 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1500 {
1501 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1502 }
1503 #else
1504 #define dm_compat_ctl_ioctl NULL
1505 #endif
1506
1507 static const struct file_operations _ctl_fops = {
1508 .unlocked_ioctl = dm_ctl_ioctl,
1509 .compat_ioctl = dm_compat_ctl_ioctl,
1510 .owner = THIS_MODULE,
1511 };
1512
1513 static struct miscdevice _dm_misc = {
1514 .minor = MISC_DYNAMIC_MINOR,
1515 .name = DM_NAME,
1516 .fops = &_ctl_fops
1517 };
1518
1519 /*
1520 * Create misc character device and link to DM_DIR/control.
1521 */
1522 int __init dm_interface_init(void)
1523 {
1524 int r;
1525
1526 r = dm_hash_init();
1527 if (r)
1528 return r;
1529
1530 r = misc_register(&_dm_misc);
1531 if (r) {
1532 DMERR("misc_register failed for control device");
1533 dm_hash_exit();
1534 return r;
1535 }
1536
1537 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1538 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1539 DM_DRIVER_EMAIL);
1540 return 0;
1541 }
1542
1543 void dm_interface_exit(void)
1544 {
1545 if (misc_deregister(&_dm_misc) < 0)
1546 DMERR("misc_deregister failed for control device");
1547
1548 dm_hash_exit();
1549 }
1550
1551 /**
1552 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1553 * @md: Pointer to mapped_device
1554 * @name: Buffer (size DM_NAME_LEN) for name
1555 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1556 */
1557 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1558 {
1559 int r = 0;
1560 struct hash_cell *hc;
1561
1562 if (!md)
1563 return -ENXIO;
1564
1565 dm_get(md);
1566 down_read(&_hash_lock);
1567 hc = dm_get_mdptr(md);
1568 if (!hc || hc->md != md) {
1569 r = -ENXIO;
1570 goto out;
1571 }
1572
1573 if (name)
1574 strcpy(name, hc->name);
1575 if (uuid)
1576 strcpy(uuid, hc->uuid ? : "");
1577
1578 out:
1579 up_read(&_hash_lock);
1580 dm_put(md);
1581
1582 return r;
1583 }
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