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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 | /* |
60 | * Protects use of mdptr to obtain hash cell name and uuid from mapped device. |
61 | */ |
62 | static DEFINE_MUTEX(dm_hash_cells_mutex); |
63 | |
64 | static void init_buckets(struct list_head *buckets) |
65 | { |
66 | unsigned int i; |
67 | |
68 | for (i = 0; i < NUM_BUCKETS; i++) |
69 | INIT_LIST_HEAD(buckets + i); |
70 | } |
71 | |
72 | static int dm_hash_init(void) |
73 | { |
74 | init_buckets(_name_buckets); |
75 | init_buckets(_uuid_buckets); |
76 | return 0; |
77 | } |
78 | |
79 | static void dm_hash_exit(void) |
80 | { |
81 | dm_hash_remove_all(0); |
82 | } |
83 | |
84 | /*----------------------------------------------------------------- |
85 | * Hash function: |
86 | * We're not really concerned with the str hash function being |
87 | * fast since it's only used by the ioctl interface. |
88 | *---------------------------------------------------------------*/ |
89 | static unsigned int hash_str(const char *str) |
90 | { |
91 | const unsigned int hash_mult = 2654435387U; |
92 | unsigned int h = 0; |
93 | |
94 | while (*str) |
95 | h = (h + (unsigned int) *str++) * hash_mult; |
96 | |
97 | return h & MASK_BUCKETS; |
98 | } |
99 | |
100 | /*----------------------------------------------------------------- |
101 | * Code for looking up a device by name |
102 | *---------------------------------------------------------------*/ |
103 | static struct hash_cell *__get_name_cell(const char *str) |
104 | { |
105 | struct hash_cell *hc; |
106 | unsigned int h = hash_str(str); |
107 | |
108 | list_for_each_entry (hc, _name_buckets + h, name_list) |
109 | if (!strcmp(hc->name, str)) { |
110 | dm_get(hc->md); |
111 | return hc; |
112 | } |
113 | |
114 | return NULL; |
115 | } |
116 | |
117 | static struct hash_cell *__get_uuid_cell(const char *str) |
118 | { |
119 | struct hash_cell *hc; |
120 | unsigned int h = hash_str(str); |
121 | |
122 | list_for_each_entry (hc, _uuid_buckets + h, uuid_list) |
123 | if (!strcmp(hc->uuid, str)) { |
124 | dm_get(hc->md); |
125 | return hc; |
126 | } |
127 | |
128 | return NULL; |
129 | } |
130 | |
131 | static struct hash_cell *__get_dev_cell(uint64_t dev) |
132 | { |
133 | struct mapped_device *md; |
134 | struct hash_cell *hc; |
135 | |
136 | md = dm_get_md(huge_decode_dev(dev)); |
137 | if (!md) |
138 | return NULL; |
139 | |
140 | hc = dm_get_mdptr(md); |
141 | if (!hc) { |
142 | dm_put(md); |
143 | return NULL; |
144 | } |
145 | |
146 | return hc; |
147 | } |
148 | |
149 | /*----------------------------------------------------------------- |
150 | * Inserting, removing and renaming a device. |
151 | *---------------------------------------------------------------*/ |
152 | static struct hash_cell *alloc_cell(const char *name, const char *uuid, |
153 | struct mapped_device *md) |
154 | { |
155 | struct hash_cell *hc; |
156 | |
157 | hc = kmalloc(sizeof(*hc), GFP_KERNEL); |
158 | if (!hc) |
159 | return NULL; |
160 | |
161 | hc->name = kstrdup(name, GFP_KERNEL); |
162 | if (!hc->name) { |
163 | kfree(hc); |
164 | return NULL; |
165 | } |
166 | |
167 | if (!uuid) |
168 | hc->uuid = NULL; |
169 | |
170 | else { |
171 | hc->uuid = kstrdup(uuid, GFP_KERNEL); |
172 | if (!hc->uuid) { |
173 | kfree(hc->name); |
174 | kfree(hc); |
175 | return NULL; |
176 | } |
177 | } |
178 | |
179 | INIT_LIST_HEAD(&hc->name_list); |
180 | INIT_LIST_HEAD(&hc->uuid_list); |
181 | hc->md = md; |
182 | hc->new_map = NULL; |
183 | return hc; |
184 | } |
185 | |
186 | static void free_cell(struct hash_cell *hc) |
187 | { |
188 | if (hc) { |
189 | kfree(hc->name); |
190 | kfree(hc->uuid); |
191 | kfree(hc); |
192 | } |
193 | } |
194 | |
195 | /* |
196 | * The kdev_t and uuid of a device can never change once it is |
197 | * initially inserted. |
198 | */ |
199 | static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) |
200 | { |
201 | struct hash_cell *cell, *hc; |
202 | |
203 | /* |
204 | * Allocate the new cells. |
205 | */ |
206 | cell = alloc_cell(name, uuid, md); |
207 | if (!cell) |
208 | return -ENOMEM; |
209 | |
210 | /* |
211 | * Insert the cell into both hash tables. |
212 | */ |
213 | down_write(&_hash_lock); |
214 | hc = __get_name_cell(name); |
215 | if (hc) { |
216 | dm_put(hc->md); |
217 | goto bad; |
218 | } |
219 | |
220 | list_add(&cell->name_list, _name_buckets + hash_str(name)); |
221 | |
222 | if (uuid) { |
223 | hc = __get_uuid_cell(uuid); |
224 | if (hc) { |
225 | list_del(&cell->name_list); |
226 | dm_put(hc->md); |
227 | goto bad; |
228 | } |
229 | list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); |
230 | } |
231 | dm_get(md); |
232 | mutex_lock(&dm_hash_cells_mutex); |
233 | dm_set_mdptr(md, cell); |
234 | mutex_unlock(&dm_hash_cells_mutex); |
235 | up_write(&_hash_lock); |
236 | |
237 | return 0; |
238 | |
239 | bad: |
240 | up_write(&_hash_lock); |
241 | free_cell(cell); |
242 | return -EBUSY; |
243 | } |
244 | |
245 | static void __hash_remove(struct hash_cell *hc) |
246 | { |
247 | struct dm_table *table; |
248 | |
249 | /* remove from the dev hash */ |
250 | list_del(&hc->uuid_list); |
251 | list_del(&hc->name_list); |
252 | mutex_lock(&dm_hash_cells_mutex); |
253 | dm_set_mdptr(hc->md, NULL); |
254 | mutex_unlock(&dm_hash_cells_mutex); |
255 | |
256 | table = dm_get_live_table(hc->md); |
257 | if (table) { |
258 | dm_table_event(table); |
259 | dm_table_put(table); |
260 | } |
261 | |
262 | if (hc->new_map) |
263 | dm_table_destroy(hc->new_map); |
264 | dm_put(hc->md); |
265 | free_cell(hc); |
266 | } |
267 | |
268 | static void dm_hash_remove_all(int keep_open_devices) |
269 | { |
270 | int i, dev_skipped; |
271 | struct hash_cell *hc; |
272 | struct mapped_device *md; |
273 | |
274 | retry: |
275 | dev_skipped = 0; |
276 | |
277 | down_write(&_hash_lock); |
278 | |
279 | for (i = 0; i < NUM_BUCKETS; i++) { |
280 | list_for_each_entry(hc, _name_buckets + i, name_list) { |
281 | md = hc->md; |
282 | dm_get(md); |
283 | |
284 | if (keep_open_devices && dm_lock_for_deletion(md)) { |
285 | dm_put(md); |
286 | dev_skipped++; |
287 | continue; |
288 | } |
289 | |
290 | __hash_remove(hc); |
291 | |
292 | up_write(&_hash_lock); |
293 | |
294 | dm_put(md); |
295 | if (likely(keep_open_devices)) |
296 | dm_destroy(md); |
297 | else |
298 | dm_destroy_immediate(md); |
299 | |
300 | /* |
301 | * Some mapped devices may be using other mapped |
302 | * devices, so repeat until we make no further |
303 | * progress. If a new mapped device is created |
304 | * here it will also get removed. |
305 | */ |
306 | goto retry; |
307 | } |
308 | } |
309 | |
310 | up_write(&_hash_lock); |
311 | |
312 | if (dev_skipped) |
313 | DMWARN("remove_all left %d open device(s)", dev_skipped); |
314 | } |
315 | |
316 | /* |
317 | * Set the uuid of a hash_cell that isn't already set. |
318 | */ |
319 | static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid) |
320 | { |
321 | mutex_lock(&dm_hash_cells_mutex); |
322 | hc->uuid = new_uuid; |
323 | mutex_unlock(&dm_hash_cells_mutex); |
324 | |
325 | list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid)); |
326 | } |
327 | |
328 | /* |
329 | * Changes the name of a hash_cell and returns the old name for |
330 | * the caller to free. |
331 | */ |
332 | static char *__change_cell_name(struct hash_cell *hc, char *new_name) |
333 | { |
334 | char *old_name; |
335 | |
336 | /* |
337 | * Rename and move the name cell. |
338 | */ |
339 | list_del(&hc->name_list); |
340 | old_name = hc->name; |
341 | |
342 | mutex_lock(&dm_hash_cells_mutex); |
343 | hc->name = new_name; |
344 | mutex_unlock(&dm_hash_cells_mutex); |
345 | |
346 | list_add(&hc->name_list, _name_buckets + hash_str(new_name)); |
347 | |
348 | return old_name; |
349 | } |
350 | |
351 | static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, |
352 | const char *new) |
353 | { |
354 | char *new_data, *old_name = NULL; |
355 | struct hash_cell *hc; |
356 | struct dm_table *table; |
357 | struct mapped_device *md; |
358 | unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
359 | |
360 | /* |
361 | * duplicate new. |
362 | */ |
363 | new_data = kstrdup(new, GFP_KERNEL); |
364 | if (!new_data) |
365 | return ERR_PTR(-ENOMEM); |
366 | |
367 | down_write(&_hash_lock); |
368 | |
369 | /* |
370 | * Is new free ? |
371 | */ |
372 | if (change_uuid) |
373 | hc = __get_uuid_cell(new); |
374 | else |
375 | hc = __get_name_cell(new); |
376 | |
377 | if (hc) { |
378 | DMWARN("Unable to change %s on mapped device %s to one that " |
379 | "already exists: %s", |
380 | change_uuid ? "uuid" : "name", |
381 | param->name, new); |
382 | dm_put(hc->md); |
383 | up_write(&_hash_lock); |
384 | kfree(new_data); |
385 | return ERR_PTR(-EBUSY); |
386 | } |
387 | |
388 | /* |
389 | * Is there such a device as 'old' ? |
390 | */ |
391 | hc = __get_name_cell(param->name); |
392 | if (!hc) { |
393 | DMWARN("Unable to rename non-existent device, %s to %s%s", |
394 | param->name, change_uuid ? "uuid " : "", new); |
395 | up_write(&_hash_lock); |
396 | kfree(new_data); |
397 | return ERR_PTR(-ENXIO); |
398 | } |
399 | |
400 | /* |
401 | * Does this device already have a uuid? |
402 | */ |
403 | if (change_uuid && hc->uuid) { |
404 | DMWARN("Unable to change uuid of mapped device %s to %s " |
405 | "because uuid is already set to %s", |
406 | param->name, new, hc->uuid); |
407 | dm_put(hc->md); |
408 | up_write(&_hash_lock); |
409 | kfree(new_data); |
410 | return ERR_PTR(-EINVAL); |
411 | } |
412 | |
413 | if (change_uuid) |
414 | __set_cell_uuid(hc, new_data); |
415 | else |
416 | old_name = __change_cell_name(hc, new_data); |
417 | |
418 | /* |
419 | * Wake up any dm event waiters. |
420 | */ |
421 | table = dm_get_live_table(hc->md); |
422 | if (table) { |
423 | dm_table_event(table); |
424 | dm_table_put(table); |
425 | } |
426 | |
427 | if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr)) |
428 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
429 | |
430 | md = hc->md; |
431 | up_write(&_hash_lock); |
432 | kfree(old_name); |
433 | |
434 | return md; |
435 | } |
436 | |
437 | /*----------------------------------------------------------------- |
438 | * Implementation of the ioctl commands |
439 | *---------------------------------------------------------------*/ |
440 | /* |
441 | * All the ioctl commands get dispatched to functions with this |
442 | * prototype. |
443 | */ |
444 | typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); |
445 | |
446 | static int remove_all(struct dm_ioctl *param, size_t param_size) |
447 | { |
448 | dm_hash_remove_all(1); |
449 | param->data_size = 0; |
450 | return 0; |
451 | } |
452 | |
453 | /* |
454 | * Round up the ptr to an 8-byte boundary. |
455 | */ |
456 | #define ALIGN_MASK 7 |
457 | static inline void *align_ptr(void *ptr) |
458 | { |
459 | return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK); |
460 | } |
461 | |
462 | /* |
463 | * Retrieves the data payload buffer from an already allocated |
464 | * struct dm_ioctl. |
465 | */ |
466 | static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, |
467 | size_t *len) |
468 | { |
469 | param->data_start = align_ptr(param + 1) - (void *) param; |
470 | |
471 | if (param->data_start < param_size) |
472 | *len = param_size - param->data_start; |
473 | else |
474 | *len = 0; |
475 | |
476 | return ((void *) param) + param->data_start; |
477 | } |
478 | |
479 | static int list_devices(struct dm_ioctl *param, size_t param_size) |
480 | { |
481 | unsigned int i; |
482 | struct hash_cell *hc; |
483 | size_t len, needed = 0; |
484 | struct gendisk *disk; |
485 | struct dm_name_list *nl, *old_nl = NULL; |
486 | |
487 | down_write(&_hash_lock); |
488 | |
489 | /* |
490 | * Loop through all the devices working out how much |
491 | * space we need. |
492 | */ |
493 | for (i = 0; i < NUM_BUCKETS; i++) { |
494 | list_for_each_entry (hc, _name_buckets + i, name_list) { |
495 | needed += sizeof(struct dm_name_list); |
496 | needed += strlen(hc->name) + 1; |
497 | needed += ALIGN_MASK; |
498 | } |
499 | } |
500 | |
501 | /* |
502 | * Grab our output buffer. |
503 | */ |
504 | nl = get_result_buffer(param, param_size, &len); |
505 | if (len < needed) { |
506 | param->flags |= DM_BUFFER_FULL_FLAG; |
507 | goto out; |
508 | } |
509 | param->data_size = param->data_start + needed; |
510 | |
511 | nl->dev = 0; /* Flags no data */ |
512 | |
513 | /* |
514 | * Now loop through filling out the names. |
515 | */ |
516 | for (i = 0; i < NUM_BUCKETS; i++) { |
517 | list_for_each_entry (hc, _name_buckets + i, name_list) { |
518 | if (old_nl) |
519 | old_nl->next = (uint32_t) ((void *) nl - |
520 | (void *) old_nl); |
521 | disk = dm_disk(hc->md); |
522 | nl->dev = huge_encode_dev(disk_devt(disk)); |
523 | nl->next = 0; |
524 | strcpy(nl->name, hc->name); |
525 | |
526 | old_nl = nl; |
527 | nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1); |
528 | } |
529 | } |
530 | |
531 | out: |
532 | up_write(&_hash_lock); |
533 | return 0; |
534 | } |
535 | |
536 | static void list_version_get_needed(struct target_type *tt, void *needed_param) |
537 | { |
538 | size_t *needed = needed_param; |
539 | |
540 | *needed += sizeof(struct dm_target_versions); |
541 | *needed += strlen(tt->name); |
542 | *needed += ALIGN_MASK; |
543 | } |
544 | |
545 | static void list_version_get_info(struct target_type *tt, void *param) |
546 | { |
547 | struct vers_iter *info = param; |
548 | |
549 | /* Check space - it might have changed since the first iteration */ |
550 | if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > |
551 | info->end) { |
552 | |
553 | info->flags = DM_BUFFER_FULL_FLAG; |
554 | return; |
555 | } |
556 | |
557 | if (info->old_vers) |
558 | info->old_vers->next = (uint32_t) ((void *)info->vers - |
559 | (void *)info->old_vers); |
560 | info->vers->version[0] = tt->version[0]; |
561 | info->vers->version[1] = tt->version[1]; |
562 | info->vers->version[2] = tt->version[2]; |
563 | info->vers->next = 0; |
564 | strcpy(info->vers->name, tt->name); |
565 | |
566 | info->old_vers = info->vers; |
567 | info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1); |
568 | } |
569 | |
570 | static int list_versions(struct dm_ioctl *param, size_t param_size) |
571 | { |
572 | size_t len, needed = 0; |
573 | struct dm_target_versions *vers; |
574 | struct vers_iter iter_info; |
575 | |
576 | /* |
577 | * Loop through all the devices working out how much |
578 | * space we need. |
579 | */ |
580 | dm_target_iterate(list_version_get_needed, &needed); |
581 | |
582 | /* |
583 | * Grab our output buffer. |
584 | */ |
585 | vers = get_result_buffer(param, param_size, &len); |
586 | if (len < needed) { |
587 | param->flags |= DM_BUFFER_FULL_FLAG; |
588 | goto out; |
589 | } |
590 | param->data_size = param->data_start + needed; |
591 | |
592 | iter_info.param_size = param_size; |
593 | iter_info.old_vers = NULL; |
594 | iter_info.vers = vers; |
595 | iter_info.flags = 0; |
596 | iter_info.end = (char *)vers+len; |
597 | |
598 | /* |
599 | * Now loop through filling out the names & versions. |
600 | */ |
601 | dm_target_iterate(list_version_get_info, &iter_info); |
602 | param->flags |= iter_info.flags; |
603 | |
604 | out: |
605 | return 0; |
606 | } |
607 | |
608 | static int check_name(const char *name) |
609 | { |
610 | if (strchr(name, '/')) { |
611 | DMWARN("invalid device name"); |
612 | return -EINVAL; |
613 | } |
614 | |
615 | return 0; |
616 | } |
617 | |
618 | /* |
619 | * On successful return, the caller must not attempt to acquire |
620 | * _hash_lock without first calling dm_table_put, because dm_table_destroy |
621 | * waits for this dm_table_put and could be called under this lock. |
622 | */ |
623 | static struct dm_table *dm_get_inactive_table(struct mapped_device *md) |
624 | { |
625 | struct hash_cell *hc; |
626 | struct dm_table *table = NULL; |
627 | |
628 | down_read(&_hash_lock); |
629 | hc = dm_get_mdptr(md); |
630 | if (!hc || hc->md != md) { |
631 | DMWARN("device has been removed from the dev hash table."); |
632 | goto out; |
633 | } |
634 | |
635 | table = hc->new_map; |
636 | if (table) |
637 | dm_table_get(table); |
638 | |
639 | out: |
640 | up_read(&_hash_lock); |
641 | |
642 | return table; |
643 | } |
644 | |
645 | static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md, |
646 | struct dm_ioctl *param) |
647 | { |
648 | return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ? |
649 | dm_get_inactive_table(md) : dm_get_live_table(md); |
650 | } |
651 | |
652 | /* |
653 | * Fills in a dm_ioctl structure, ready for sending back to |
654 | * userland. |
655 | */ |
656 | static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) |
657 | { |
658 | struct gendisk *disk = dm_disk(md); |
659 | struct dm_table *table; |
660 | |
661 | param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | |
662 | DM_ACTIVE_PRESENT_FLAG); |
663 | |
664 | if (dm_suspended_md(md)) |
665 | param->flags |= DM_SUSPEND_FLAG; |
666 | |
667 | param->dev = huge_encode_dev(disk_devt(disk)); |
668 | |
669 | /* |
670 | * Yes, this will be out of date by the time it gets back |
671 | * to userland, but it is still very useful for |
672 | * debugging. |
673 | */ |
674 | param->open_count = dm_open_count(md); |
675 | |
676 | param->event_nr = dm_get_event_nr(md); |
677 | param->target_count = 0; |
678 | |
679 | table = dm_get_live_table(md); |
680 | if (table) { |
681 | if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) { |
682 | if (get_disk_ro(disk)) |
683 | param->flags |= DM_READONLY_FLAG; |
684 | param->target_count = dm_table_get_num_targets(table); |
685 | } |
686 | dm_table_put(table); |
687 | |
688 | param->flags |= DM_ACTIVE_PRESENT_FLAG; |
689 | } |
690 | |
691 | if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) { |
692 | table = dm_get_inactive_table(md); |
693 | if (table) { |
694 | if (!(dm_table_get_mode(table) & FMODE_WRITE)) |
695 | param->flags |= DM_READONLY_FLAG; |
696 | param->target_count = dm_table_get_num_targets(table); |
697 | dm_table_put(table); |
698 | } |
699 | } |
700 | } |
701 | |
702 | static int dev_create(struct dm_ioctl *param, size_t param_size) |
703 | { |
704 | int r, m = DM_ANY_MINOR; |
705 | struct mapped_device *md; |
706 | |
707 | r = check_name(param->name); |
708 | if (r) |
709 | return r; |
710 | |
711 | if (param->flags & DM_PERSISTENT_DEV_FLAG) |
712 | m = MINOR(huge_decode_dev(param->dev)); |
713 | |
714 | r = dm_create(m, &md); |
715 | if (r) |
716 | return r; |
717 | |
718 | r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); |
719 | if (r) { |
720 | dm_put(md); |
721 | dm_destroy(md); |
722 | return r; |
723 | } |
724 | |
725 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
726 | |
727 | __dev_status(md, param); |
728 | |
729 | dm_put(md); |
730 | |
731 | return 0; |
732 | } |
733 | |
734 | /* |
735 | * Always use UUID for lookups if it's present, otherwise use name or dev. |
736 | */ |
737 | static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) |
738 | { |
739 | struct hash_cell *hc = NULL; |
740 | |
741 | if (*param->uuid) { |
742 | if (*param->name || param->dev) |
743 | return NULL; |
744 | |
745 | hc = __get_uuid_cell(param->uuid); |
746 | if (!hc) |
747 | return NULL; |
748 | } else if (*param->name) { |
749 | if (param->dev) |
750 | return NULL; |
751 | |
752 | hc = __get_name_cell(param->name); |
753 | if (!hc) |
754 | return NULL; |
755 | } else if (param->dev) { |
756 | hc = __get_dev_cell(param->dev); |
757 | if (!hc) |
758 | return NULL; |
759 | } else |
760 | return NULL; |
761 | |
762 | /* |
763 | * Sneakily write in both the name and the uuid |
764 | * while we have the cell. |
765 | */ |
766 | strlcpy(param->name, hc->name, sizeof(param->name)); |
767 | if (hc->uuid) |
768 | strlcpy(param->uuid, hc->uuid, sizeof(param->uuid)); |
769 | else |
770 | param->uuid[0] = '\0'; |
771 | |
772 | if (hc->new_map) |
773 | param->flags |= DM_INACTIVE_PRESENT_FLAG; |
774 | else |
775 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
776 | |
777 | return hc; |
778 | } |
779 | |
780 | static struct mapped_device *find_device(struct dm_ioctl *param) |
781 | { |
782 | struct hash_cell *hc; |
783 | struct mapped_device *md = NULL; |
784 | |
785 | down_read(&_hash_lock); |
786 | hc = __find_device_hash_cell(param); |
787 | if (hc) |
788 | md = hc->md; |
789 | up_read(&_hash_lock); |
790 | |
791 | return md; |
792 | } |
793 | |
794 | static int dev_remove(struct dm_ioctl *param, size_t param_size) |
795 | { |
796 | struct hash_cell *hc; |
797 | struct mapped_device *md; |
798 | int r; |
799 | |
800 | down_write(&_hash_lock); |
801 | hc = __find_device_hash_cell(param); |
802 | |
803 | if (!hc) { |
804 | DMDEBUG_LIMIT("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 | /* |
812 | * Ensure the device is not open and nothing further can open it. |
813 | */ |
814 | r = dm_lock_for_deletion(md); |
815 | if (r) { |
816 | DMDEBUG_LIMIT("unable to remove open device %s", hc->name); |
817 | up_write(&_hash_lock); |
818 | dm_put(md); |
819 | return r; |
820 | } |
821 | |
822 | __hash_remove(hc); |
823 | up_write(&_hash_lock); |
824 | |
825 | if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr)) |
826 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
827 | |
828 | dm_put(md); |
829 | dm_destroy(md); |
830 | return 0; |
831 | } |
832 | |
833 | /* |
834 | * Check a string doesn't overrun the chunk of |
835 | * memory we copied from userland. |
836 | */ |
837 | static int invalid_str(char *str, void *end) |
838 | { |
839 | while ((void *) str < end) |
840 | if (!*str++) |
841 | return 0; |
842 | |
843 | return -EINVAL; |
844 | } |
845 | |
846 | static int dev_rename(struct dm_ioctl *param, size_t param_size) |
847 | { |
848 | int r; |
849 | char *new_data = (char *) param + param->data_start; |
850 | struct mapped_device *md; |
851 | unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
852 | |
853 | if (new_data < param->data || |
854 | invalid_str(new_data, (void *) param + param_size) || |
855 | strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) { |
856 | DMWARN("Invalid new mapped device name or uuid string supplied."); |
857 | return -EINVAL; |
858 | } |
859 | |
860 | if (!change_uuid) { |
861 | r = check_name(new_data); |
862 | if (r) |
863 | return r; |
864 | } |
865 | |
866 | md = dm_hash_rename(param, new_data); |
867 | if (IS_ERR(md)) |
868 | return PTR_ERR(md); |
869 | |
870 | __dev_status(md, param); |
871 | dm_put(md); |
872 | |
873 | return 0; |
874 | } |
875 | |
876 | static int dev_set_geometry(struct dm_ioctl *param, size_t param_size) |
877 | { |
878 | int r = -EINVAL, x; |
879 | struct mapped_device *md; |
880 | struct hd_geometry geometry; |
881 | unsigned long indata[4]; |
882 | char *geostr = (char *) param + param->data_start; |
883 | char dummy; |
884 | |
885 | md = find_device(param); |
886 | if (!md) |
887 | return -ENXIO; |
888 | |
889 | if (geostr < param->data || |
890 | invalid_str(geostr, (void *) param + param_size)) { |
891 | DMWARN("Invalid geometry supplied."); |
892 | goto out; |
893 | } |
894 | |
895 | x = sscanf(geostr, "%lu %lu %lu %lu%c", indata, |
896 | indata + 1, indata + 2, indata + 3, &dummy); |
897 | |
898 | if (x != 4) { |
899 | DMWARN("Unable to interpret geometry settings."); |
900 | goto out; |
901 | } |
902 | |
903 | if (indata[0] > 65535 || indata[1] > 255 || |
904 | indata[2] > 255 || indata[3] > ULONG_MAX) { |
905 | DMWARN("Geometry exceeds range limits."); |
906 | goto out; |
907 | } |
908 | |
909 | geometry.cylinders = indata[0]; |
910 | geometry.heads = indata[1]; |
911 | geometry.sectors = indata[2]; |
912 | geometry.start = indata[3]; |
913 | |
914 | r = dm_set_geometry(md, &geometry); |
915 | |
916 | param->data_size = 0; |
917 | |
918 | out: |
919 | dm_put(md); |
920 | return r; |
921 | } |
922 | |
923 | static int do_suspend(struct dm_ioctl *param) |
924 | { |
925 | int r = 0; |
926 | unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
927 | struct mapped_device *md; |
928 | |
929 | md = find_device(param); |
930 | if (!md) |
931 | return -ENXIO; |
932 | |
933 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
934 | suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
935 | if (param->flags & DM_NOFLUSH_FLAG) |
936 | suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
937 | |
938 | if (!dm_suspended_md(md)) { |
939 | r = dm_suspend(md, suspend_flags); |
940 | if (r) |
941 | goto out; |
942 | } |
943 | |
944 | __dev_status(md, param); |
945 | |
946 | out: |
947 | dm_put(md); |
948 | |
949 | return r; |
950 | } |
951 | |
952 | static int do_resume(struct dm_ioctl *param) |
953 | { |
954 | int r = 0; |
955 | unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
956 | struct hash_cell *hc; |
957 | struct mapped_device *md; |
958 | struct dm_table *new_map, *old_map = NULL; |
959 | |
960 | down_write(&_hash_lock); |
961 | |
962 | hc = __find_device_hash_cell(param); |
963 | if (!hc) { |
964 | DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
965 | up_write(&_hash_lock); |
966 | return -ENXIO; |
967 | } |
968 | |
969 | md = hc->md; |
970 | |
971 | new_map = hc->new_map; |
972 | hc->new_map = NULL; |
973 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
974 | |
975 | up_write(&_hash_lock); |
976 | |
977 | /* Do we need to load a new map ? */ |
978 | if (new_map) { |
979 | /* Suspend if it isn't already suspended */ |
980 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
981 | suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
982 | if (param->flags & DM_NOFLUSH_FLAG) |
983 | suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
984 | if (!dm_suspended_md(md)) |
985 | dm_suspend(md, suspend_flags); |
986 | |
987 | old_map = dm_swap_table(md, new_map); |
988 | if (IS_ERR(old_map)) { |
989 | dm_table_destroy(new_map); |
990 | dm_put(md); |
991 | return PTR_ERR(old_map); |
992 | } |
993 | |
994 | if (dm_table_get_mode(new_map) & FMODE_WRITE) |
995 | set_disk_ro(dm_disk(md), 0); |
996 | else |
997 | set_disk_ro(dm_disk(md), 1); |
998 | } |
999 | |
1000 | if (dm_suspended_md(md)) { |
1001 | r = dm_resume(md); |
1002 | if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr)) |
1003 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
1004 | } |
1005 | |
1006 | if (old_map) |
1007 | dm_table_destroy(old_map); |
1008 | |
1009 | if (!r) |
1010 | __dev_status(md, param); |
1011 | |
1012 | dm_put(md); |
1013 | return r; |
1014 | } |
1015 | |
1016 | /* |
1017 | * Set or unset the suspension state of a device. |
1018 | * If the device already is in the requested state we just return its status. |
1019 | */ |
1020 | static int dev_suspend(struct dm_ioctl *param, size_t param_size) |
1021 | { |
1022 | if (param->flags & DM_SUSPEND_FLAG) |
1023 | return do_suspend(param); |
1024 | |
1025 | return do_resume(param); |
1026 | } |
1027 | |
1028 | /* |
1029 | * Copies device info back to user space, used by |
1030 | * the create and info ioctls. |
1031 | */ |
1032 | static int dev_status(struct dm_ioctl *param, size_t param_size) |
1033 | { |
1034 | struct mapped_device *md; |
1035 | |
1036 | md = find_device(param); |
1037 | if (!md) |
1038 | return -ENXIO; |
1039 | |
1040 | __dev_status(md, param); |
1041 | dm_put(md); |
1042 | |
1043 | return 0; |
1044 | } |
1045 | |
1046 | /* |
1047 | * Build up the status struct for each target |
1048 | */ |
1049 | static void retrieve_status(struct dm_table *table, |
1050 | struct dm_ioctl *param, size_t param_size) |
1051 | { |
1052 | unsigned int i, num_targets; |
1053 | struct dm_target_spec *spec; |
1054 | char *outbuf, *outptr; |
1055 | status_type_t type; |
1056 | size_t remaining, len, used = 0; |
1057 | unsigned status_flags = 0; |
1058 | |
1059 | outptr = outbuf = get_result_buffer(param, param_size, &len); |
1060 | |
1061 | if (param->flags & DM_STATUS_TABLE_FLAG) |
1062 | type = STATUSTYPE_TABLE; |
1063 | else |
1064 | type = STATUSTYPE_INFO; |
1065 | |
1066 | /* Get all the target info */ |
1067 | num_targets = dm_table_get_num_targets(table); |
1068 | for (i = 0; i < num_targets; i++) { |
1069 | struct dm_target *ti = dm_table_get_target(table, i); |
1070 | size_t l; |
1071 | |
1072 | remaining = len - (outptr - outbuf); |
1073 | if (remaining <= sizeof(struct dm_target_spec)) { |
1074 | param->flags |= DM_BUFFER_FULL_FLAG; |
1075 | break; |
1076 | } |
1077 | |
1078 | spec = (struct dm_target_spec *) outptr; |
1079 | |
1080 | spec->status = 0; |
1081 | spec->sector_start = ti->begin; |
1082 | spec->length = ti->len; |
1083 | strncpy(spec->target_type, ti->type->name, |
1084 | sizeof(spec->target_type)); |
1085 | |
1086 | outptr += sizeof(struct dm_target_spec); |
1087 | remaining = len - (outptr - outbuf); |
1088 | if (remaining <= 0) { |
1089 | param->flags |= DM_BUFFER_FULL_FLAG; |
1090 | break; |
1091 | } |
1092 | |
1093 | /* Get the status/table string from the target driver */ |
1094 | if (ti->type->status) { |
1095 | if (param->flags & DM_NOFLUSH_FLAG) |
1096 | status_flags |= DM_STATUS_NOFLUSH_FLAG; |
1097 | ti->type->status(ti, type, status_flags, outptr, remaining); |
1098 | } else |
1099 | outptr[0] = '\0'; |
1100 | |
1101 | l = strlen(outptr) + 1; |
1102 | if (l == remaining) { |
1103 | param->flags |= DM_BUFFER_FULL_FLAG; |
1104 | break; |
1105 | } |
1106 | |
1107 | outptr += l; |
1108 | used = param->data_start + (outptr - outbuf); |
1109 | |
1110 | outptr = align_ptr(outptr); |
1111 | spec->next = outptr - outbuf; |
1112 | } |
1113 | |
1114 | if (used) |
1115 | param->data_size = used; |
1116 | |
1117 | param->target_count = num_targets; |
1118 | } |
1119 | |
1120 | /* |
1121 | * Wait for a device to report an event |
1122 | */ |
1123 | static int dev_wait(struct dm_ioctl *param, size_t param_size) |
1124 | { |
1125 | int r = 0; |
1126 | struct mapped_device *md; |
1127 | struct dm_table *table; |
1128 | |
1129 | md = find_device(param); |
1130 | if (!md) |
1131 | return -ENXIO; |
1132 | |
1133 | /* |
1134 | * Wait for a notification event |
1135 | */ |
1136 | if (dm_wait_event(md, param->event_nr)) { |
1137 | r = -ERESTARTSYS; |
1138 | goto out; |
1139 | } |
1140 | |
1141 | /* |
1142 | * The userland program is going to want to know what |
1143 | * changed to trigger the event, so we may as well tell |
1144 | * him and save an ioctl. |
1145 | */ |
1146 | __dev_status(md, param); |
1147 | |
1148 | table = dm_get_live_or_inactive_table(md, param); |
1149 | if (table) { |
1150 | retrieve_status(table, param, param_size); |
1151 | dm_table_put(table); |
1152 | } |
1153 | |
1154 | out: |
1155 | dm_put(md); |
1156 | |
1157 | return r; |
1158 | } |
1159 | |
1160 | static inline fmode_t get_mode(struct dm_ioctl *param) |
1161 | { |
1162 | fmode_t mode = FMODE_READ | FMODE_WRITE; |
1163 | |
1164 | if (param->flags & DM_READONLY_FLAG) |
1165 | mode = FMODE_READ; |
1166 | |
1167 | return mode; |
1168 | } |
1169 | |
1170 | static int next_target(struct dm_target_spec *last, uint32_t next, void *end, |
1171 | struct dm_target_spec **spec, char **target_params) |
1172 | { |
1173 | *spec = (struct dm_target_spec *) ((unsigned char *) last + next); |
1174 | *target_params = (char *) (*spec + 1); |
1175 | |
1176 | if (*spec < (last + 1)) |
1177 | return -EINVAL; |
1178 | |
1179 | return invalid_str(*target_params, end); |
1180 | } |
1181 | |
1182 | static int populate_table(struct dm_table *table, |
1183 | struct dm_ioctl *param, size_t param_size) |
1184 | { |
1185 | int r; |
1186 | unsigned int i = 0; |
1187 | struct dm_target_spec *spec = (struct dm_target_spec *) param; |
1188 | uint32_t next = param->data_start; |
1189 | void *end = (void *) param + param_size; |
1190 | char *target_params; |
1191 | |
1192 | if (!param->target_count) { |
1193 | DMWARN("populate_table: no targets specified"); |
1194 | return -EINVAL; |
1195 | } |
1196 | |
1197 | for (i = 0; i < param->target_count; i++) { |
1198 | |
1199 | r = next_target(spec, next, end, &spec, &target_params); |
1200 | if (r) { |
1201 | DMWARN("unable to find target"); |
1202 | return r; |
1203 | } |
1204 | |
1205 | r = dm_table_add_target(table, spec->target_type, |
1206 | (sector_t) spec->sector_start, |
1207 | (sector_t) spec->length, |
1208 | target_params); |
1209 | if (r) { |
1210 | DMWARN("error adding target to table"); |
1211 | return r; |
1212 | } |
1213 | |
1214 | next = spec->next; |
1215 | } |
1216 | |
1217 | return dm_table_complete(table); |
1218 | } |
1219 | |
1220 | static int table_load(struct dm_ioctl *param, size_t param_size) |
1221 | { |
1222 | int r; |
1223 | struct hash_cell *hc; |
1224 | struct dm_table *t; |
1225 | struct mapped_device *md; |
1226 | struct target_type *immutable_target_type; |
1227 | |
1228 | md = find_device(param); |
1229 | if (!md) |
1230 | return -ENXIO; |
1231 | |
1232 | r = dm_table_create(&t, get_mode(param), param->target_count, md); |
1233 | if (r) |
1234 | goto out; |
1235 | |
1236 | r = populate_table(t, param, param_size); |
1237 | if (r) { |
1238 | dm_table_destroy(t); |
1239 | goto out; |
1240 | } |
1241 | |
1242 | immutable_target_type = dm_get_immutable_target_type(md); |
1243 | if (immutable_target_type && |
1244 | (immutable_target_type != dm_table_get_immutable_target_type(t))) { |
1245 | DMWARN("can't replace immutable target type %s", |
1246 | immutable_target_type->name); |
1247 | dm_table_destroy(t); |
1248 | r = -EINVAL; |
1249 | goto out; |
1250 | } |
1251 | |
1252 | /* Protect md->type and md->queue against concurrent table loads. */ |
1253 | dm_lock_md_type(md); |
1254 | if (dm_get_md_type(md) == DM_TYPE_NONE) |
1255 | /* Initial table load: acquire type of table. */ |
1256 | dm_set_md_type(md, dm_table_get_type(t)); |
1257 | else if (dm_get_md_type(md) != dm_table_get_type(t)) { |
1258 | DMWARN("can't change device type after initial table load."); |
1259 | dm_table_destroy(t); |
1260 | dm_unlock_md_type(md); |
1261 | r = -EINVAL; |
1262 | goto out; |
1263 | } |
1264 | |
1265 | /* setup md->queue to reflect md's type (may block) */ |
1266 | r = dm_setup_md_queue(md); |
1267 | if (r) { |
1268 | DMWARN("unable to set up device queue for new table."); |
1269 | dm_table_destroy(t); |
1270 | dm_unlock_md_type(md); |
1271 | goto out; |
1272 | } |
1273 | dm_unlock_md_type(md); |
1274 | |
1275 | /* stage inactive table */ |
1276 | down_write(&_hash_lock); |
1277 | hc = dm_get_mdptr(md); |
1278 | if (!hc || hc->md != md) { |
1279 | DMWARN("device has been removed from the dev hash table."); |
1280 | dm_table_destroy(t); |
1281 | up_write(&_hash_lock); |
1282 | r = -ENXIO; |
1283 | goto out; |
1284 | } |
1285 | |
1286 | if (hc->new_map) |
1287 | dm_table_destroy(hc->new_map); |
1288 | hc->new_map = t; |
1289 | up_write(&_hash_lock); |
1290 | |
1291 | param->flags |= DM_INACTIVE_PRESENT_FLAG; |
1292 | __dev_status(md, param); |
1293 | |
1294 | out: |
1295 | dm_put(md); |
1296 | |
1297 | return r; |
1298 | } |
1299 | |
1300 | static int table_clear(struct dm_ioctl *param, size_t param_size) |
1301 | { |
1302 | struct hash_cell *hc; |
1303 | struct mapped_device *md; |
1304 | |
1305 | down_write(&_hash_lock); |
1306 | |
1307 | hc = __find_device_hash_cell(param); |
1308 | if (!hc) { |
1309 | DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
1310 | up_write(&_hash_lock); |
1311 | return -ENXIO; |
1312 | } |
1313 | |
1314 | if (hc->new_map) { |
1315 | dm_table_destroy(hc->new_map); |
1316 | hc->new_map = NULL; |
1317 | } |
1318 | |
1319 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
1320 | |
1321 | __dev_status(hc->md, param); |
1322 | md = hc->md; |
1323 | up_write(&_hash_lock); |
1324 | dm_put(md); |
1325 | |
1326 | return 0; |
1327 | } |
1328 | |
1329 | /* |
1330 | * Retrieves a list of devices used by a particular dm device. |
1331 | */ |
1332 | static void retrieve_deps(struct dm_table *table, |
1333 | struct dm_ioctl *param, size_t param_size) |
1334 | { |
1335 | unsigned int count = 0; |
1336 | struct list_head *tmp; |
1337 | size_t len, needed; |
1338 | struct dm_dev_internal *dd; |
1339 | struct dm_target_deps *deps; |
1340 | |
1341 | deps = get_result_buffer(param, param_size, &len); |
1342 | |
1343 | /* |
1344 | * Count the devices. |
1345 | */ |
1346 | list_for_each (tmp, dm_table_get_devices(table)) |
1347 | count++; |
1348 | |
1349 | /* |
1350 | * Check we have enough space. |
1351 | */ |
1352 | needed = sizeof(*deps) + (sizeof(*deps->dev) * count); |
1353 | if (len < needed) { |
1354 | param->flags |= DM_BUFFER_FULL_FLAG; |
1355 | return; |
1356 | } |
1357 | |
1358 | /* |
1359 | * Fill in the devices. |
1360 | */ |
1361 | deps->count = count; |
1362 | count = 0; |
1363 | list_for_each_entry (dd, dm_table_get_devices(table), list) |
1364 | deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev); |
1365 | |
1366 | param->data_size = param->data_start + needed; |
1367 | } |
1368 | |
1369 | static int table_deps(struct dm_ioctl *param, size_t param_size) |
1370 | { |
1371 | struct mapped_device *md; |
1372 | struct dm_table *table; |
1373 | |
1374 | md = find_device(param); |
1375 | if (!md) |
1376 | return -ENXIO; |
1377 | |
1378 | __dev_status(md, param); |
1379 | |
1380 | table = dm_get_live_or_inactive_table(md, param); |
1381 | if (table) { |
1382 | retrieve_deps(table, param, param_size); |
1383 | dm_table_put(table); |
1384 | } |
1385 | |
1386 | dm_put(md); |
1387 | |
1388 | return 0; |
1389 | } |
1390 | |
1391 | /* |
1392 | * Return the status of a device as a text string for each |
1393 | * target. |
1394 | */ |
1395 | static int table_status(struct dm_ioctl *param, size_t param_size) |
1396 | { |
1397 | struct mapped_device *md; |
1398 | struct dm_table *table; |
1399 | |
1400 | md = find_device(param); |
1401 | if (!md) |
1402 | return -ENXIO; |
1403 | |
1404 | __dev_status(md, param); |
1405 | |
1406 | table = dm_get_live_or_inactive_table(md, param); |
1407 | if (table) { |
1408 | retrieve_status(table, param, param_size); |
1409 | dm_table_put(table); |
1410 | } |
1411 | |
1412 | dm_put(md); |
1413 | |
1414 | return 0; |
1415 | } |
1416 | |
1417 | static bool buffer_test_overflow(char *result, unsigned maxlen) |
1418 | { |
1419 | return !maxlen || strlen(result) + 1 >= maxlen; |
1420 | } |
1421 | |
1422 | /* |
1423 | * Process device-mapper dependent messages. |
1424 | * Returns a number <= 1 if message was processed by device mapper. |
1425 | * Returns 2 if message should be delivered to the target. |
1426 | */ |
1427 | static int message_for_md(struct mapped_device *md, unsigned argc, char **argv, |
1428 | char *result, unsigned maxlen) |
1429 | { |
1430 | return 2; |
1431 | } |
1432 | |
1433 | /* |
1434 | * Pass a message to the target that's at the supplied device offset. |
1435 | */ |
1436 | static int target_message(struct dm_ioctl *param, size_t param_size) |
1437 | { |
1438 | int r, argc; |
1439 | char **argv; |
1440 | struct mapped_device *md; |
1441 | struct dm_table *table; |
1442 | struct dm_target *ti; |
1443 | struct dm_target_msg *tmsg = (void *) param + param->data_start; |
1444 | size_t maxlen; |
1445 | char *result = get_result_buffer(param, param_size, &maxlen); |
1446 | |
1447 | md = find_device(param); |
1448 | if (!md) |
1449 | return -ENXIO; |
1450 | |
1451 | if (tmsg < (struct dm_target_msg *) param->data || |
1452 | invalid_str(tmsg->message, (void *) param + param_size)) { |
1453 | DMWARN("Invalid target message parameters."); |
1454 | r = -EINVAL; |
1455 | goto out; |
1456 | } |
1457 | |
1458 | r = dm_split_args(&argc, &argv, tmsg->message); |
1459 | if (r) { |
1460 | DMWARN("Failed to split target message parameters"); |
1461 | goto out; |
1462 | } |
1463 | |
1464 | if (!argc) { |
1465 | DMWARN("Empty message received."); |
1466 | goto out_argv; |
1467 | } |
1468 | |
1469 | r = message_for_md(md, argc, argv, result, maxlen); |
1470 | if (r <= 1) |
1471 | goto out_argv; |
1472 | |
1473 | table = dm_get_live_table(md); |
1474 | if (!table) |
1475 | goto out_argv; |
1476 | |
1477 | if (dm_deleting_md(md)) { |
1478 | r = -ENXIO; |
1479 | goto out_table; |
1480 | } |
1481 | |
1482 | ti = dm_table_find_target(table, tmsg->sector); |
1483 | if (!dm_target_is_valid(ti)) { |
1484 | DMWARN("Target message sector outside device."); |
1485 | r = -EINVAL; |
1486 | } else if (ti->type->message) |
1487 | r = ti->type->message(ti, argc, argv); |
1488 | else { |
1489 | DMWARN("Target type does not support messages"); |
1490 | r = -EINVAL; |
1491 | } |
1492 | |
1493 | out_table: |
1494 | dm_table_put(table); |
1495 | out_argv: |
1496 | kfree(argv); |
1497 | out: |
1498 | if (r >= 0) |
1499 | __dev_status(md, param); |
1500 | |
1501 | if (r == 1) { |
1502 | param->flags |= DM_DATA_OUT_FLAG; |
1503 | if (buffer_test_overflow(result, maxlen)) |
1504 | param->flags |= DM_BUFFER_FULL_FLAG; |
1505 | else |
1506 | param->data_size = param->data_start + strlen(result) + 1; |
1507 | r = 0; |
1508 | } |
1509 | |
1510 | dm_put(md); |
1511 | return r; |
1512 | } |
1513 | |
1514 | /* |
1515 | * The ioctl parameter block consists of two parts, a dm_ioctl struct |
1516 | * followed by a data buffer. This flag is set if the second part, |
1517 | * which has a variable size, is not used by the function processing |
1518 | * the ioctl. |
1519 | */ |
1520 | #define IOCTL_FLAGS_NO_PARAMS 1 |
1521 | |
1522 | /*----------------------------------------------------------------- |
1523 | * Implementation of open/close/ioctl on the special char |
1524 | * device. |
1525 | *---------------------------------------------------------------*/ |
1526 | static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) |
1527 | { |
1528 | static struct { |
1529 | int cmd; |
1530 | int flags; |
1531 | ioctl_fn fn; |
1532 | } _ioctls[] = { |
1533 | {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */ |
1534 | {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all}, |
1535 | {DM_LIST_DEVICES_CMD, 0, list_devices}, |
1536 | |
1537 | {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create}, |
1538 | {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove}, |
1539 | {DM_DEV_RENAME_CMD, 0, dev_rename}, |
1540 | {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend}, |
1541 | {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status}, |
1542 | {DM_DEV_WAIT_CMD, 0, dev_wait}, |
1543 | |
1544 | {DM_TABLE_LOAD_CMD, 0, table_load}, |
1545 | {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear}, |
1546 | {DM_TABLE_DEPS_CMD, 0, table_deps}, |
1547 | {DM_TABLE_STATUS_CMD, 0, table_status}, |
1548 | |
1549 | {DM_LIST_VERSIONS_CMD, 0, list_versions}, |
1550 | |
1551 | {DM_TARGET_MSG_CMD, 0, target_message}, |
1552 | {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry} |
1553 | }; |
1554 | |
1555 | if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) |
1556 | return NULL; |
1557 | |
1558 | *ioctl_flags = _ioctls[cmd].flags; |
1559 | return _ioctls[cmd].fn; |
1560 | } |
1561 | |
1562 | /* |
1563 | * As well as checking the version compatibility this always |
1564 | * copies the kernel interface version out. |
1565 | */ |
1566 | static int check_version(unsigned int cmd, struct dm_ioctl __user *user) |
1567 | { |
1568 | uint32_t version[3]; |
1569 | int r = 0; |
1570 | |
1571 | if (copy_from_user(version, user->version, sizeof(version))) |
1572 | return -EFAULT; |
1573 | |
1574 | if ((DM_VERSION_MAJOR != version[0]) || |
1575 | (DM_VERSION_MINOR < version[1])) { |
1576 | DMWARN("ioctl interface mismatch: " |
1577 | "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)", |
1578 | DM_VERSION_MAJOR, DM_VERSION_MINOR, |
1579 | DM_VERSION_PATCHLEVEL, |
1580 | version[0], version[1], version[2], cmd); |
1581 | r = -EINVAL; |
1582 | } |
1583 | |
1584 | /* |
1585 | * Fill in the kernel version. |
1586 | */ |
1587 | version[0] = DM_VERSION_MAJOR; |
1588 | version[1] = DM_VERSION_MINOR; |
1589 | version[2] = DM_VERSION_PATCHLEVEL; |
1590 | if (copy_to_user(user->version, version, sizeof(version))) |
1591 | return -EFAULT; |
1592 | |
1593 | return r; |
1594 | } |
1595 | |
1596 | #define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */ |
1597 | #define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */ |
1598 | #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */ |
1599 | |
1600 | static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags) |
1601 | { |
1602 | if (param_flags & DM_WIPE_BUFFER) |
1603 | memset(param, 0, param_size); |
1604 | |
1605 | if (param_flags & DM_PARAMS_KMALLOC) |
1606 | kfree(param); |
1607 | if (param_flags & DM_PARAMS_VMALLOC) |
1608 | vfree(param); |
1609 | } |
1610 | |
1611 | static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel, |
1612 | int ioctl_flags, |
1613 | struct dm_ioctl **param, int *param_flags) |
1614 | { |
1615 | struct dm_ioctl *dmi; |
1616 | int secure_data; |
1617 | const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data); |
1618 | |
1619 | if (copy_from_user(param_kernel, user, minimum_data_size)) |
1620 | return -EFAULT; |
1621 | |
1622 | if (param_kernel->data_size < minimum_data_size) |
1623 | return -EINVAL; |
1624 | |
1625 | secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG; |
1626 | |
1627 | *param_flags = secure_data ? DM_WIPE_BUFFER : 0; |
1628 | |
1629 | if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) { |
1630 | dmi = param_kernel; |
1631 | dmi->data_size = minimum_data_size; |
1632 | goto data_copied; |
1633 | } |
1634 | |
1635 | /* |
1636 | * Try to avoid low memory issues when a device is suspended. |
1637 | * Use kmalloc() rather than vmalloc() when we can. |
1638 | */ |
1639 | dmi = NULL; |
1640 | if (param_kernel->data_size <= KMALLOC_MAX_SIZE) { |
1641 | dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); |
1642 | if (dmi) |
1643 | *param_flags |= DM_PARAMS_KMALLOC; |
1644 | } |
1645 | |
1646 | if (!dmi) { |
1647 | dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL); |
1648 | if (dmi) |
1649 | *param_flags |= DM_PARAMS_VMALLOC; |
1650 | } |
1651 | |
1652 | if (!dmi) { |
1653 | if (secure_data && clear_user(user, param_kernel->data_size)) |
1654 | return -EFAULT; |
1655 | return -ENOMEM; |
1656 | } |
1657 | |
1658 | if (copy_from_user(dmi, user, param_kernel->data_size)) |
1659 | goto bad; |
1660 | |
1661 | data_copied: |
1662 | /* |
1663 | * Abort if something changed the ioctl data while it was being copied. |
1664 | */ |
1665 | if (dmi->data_size != param_kernel->data_size) { |
1666 | DMERR("rejecting ioctl: data size modified while processing parameters"); |
1667 | goto bad; |
1668 | } |
1669 | |
1670 | /* Wipe the user buffer so we do not return it to userspace */ |
1671 | if (secure_data && clear_user(user, param_kernel->data_size)) |
1672 | goto bad; |
1673 | |
1674 | *param = dmi; |
1675 | return 0; |
1676 | |
1677 | bad: |
1678 | free_params(dmi, param_kernel->data_size, *param_flags); |
1679 | |
1680 | return -EFAULT; |
1681 | } |
1682 | |
1683 | static int validate_params(uint cmd, struct dm_ioctl *param) |
1684 | { |
1685 | /* Always clear this flag */ |
1686 | param->flags &= ~DM_BUFFER_FULL_FLAG; |
1687 | param->flags &= ~DM_UEVENT_GENERATED_FLAG; |
1688 | param->flags &= ~DM_SECURE_DATA_FLAG; |
1689 | param->flags &= ~DM_DATA_OUT_FLAG; |
1690 | |
1691 | /* Ignores parameters */ |
1692 | if (cmd == DM_REMOVE_ALL_CMD || |
1693 | cmd == DM_LIST_DEVICES_CMD || |
1694 | cmd == DM_LIST_VERSIONS_CMD) |
1695 | return 0; |
1696 | |
1697 | if ((cmd == DM_DEV_CREATE_CMD)) { |
1698 | if (!*param->name) { |
1699 | DMWARN("name not supplied when creating device"); |
1700 | return -EINVAL; |
1701 | } |
1702 | } else if ((*param->uuid && *param->name)) { |
1703 | DMWARN("only supply one of name or uuid, cmd(%u)", cmd); |
1704 | return -EINVAL; |
1705 | } |
1706 | |
1707 | /* Ensure strings are terminated */ |
1708 | param->name[DM_NAME_LEN - 1] = '\0'; |
1709 | param->uuid[DM_UUID_LEN - 1] = '\0'; |
1710 | |
1711 | return 0; |
1712 | } |
1713 | |
1714 | static int ctl_ioctl(uint command, struct dm_ioctl __user *user) |
1715 | { |
1716 | int r = 0; |
1717 | int ioctl_flags; |
1718 | int param_flags; |
1719 | unsigned int cmd; |
1720 | struct dm_ioctl *uninitialized_var(param); |
1721 | ioctl_fn fn = NULL; |
1722 | size_t input_param_size; |
1723 | struct dm_ioctl param_kernel; |
1724 | |
1725 | /* only root can play with this */ |
1726 | if (!capable(CAP_SYS_ADMIN)) |
1727 | return -EACCES; |
1728 | |
1729 | if (_IOC_TYPE(command) != DM_IOCTL) |
1730 | return -ENOTTY; |
1731 | |
1732 | cmd = _IOC_NR(command); |
1733 | |
1734 | /* |
1735 | * Check the interface version passed in. This also |
1736 | * writes out the kernel's interface version. |
1737 | */ |
1738 | r = check_version(cmd, user); |
1739 | if (r) |
1740 | return r; |
1741 | |
1742 | /* |
1743 | * Nothing more to do for the version command. |
1744 | */ |
1745 | if (cmd == DM_VERSION_CMD) |
1746 | return 0; |
1747 | |
1748 | fn = lookup_ioctl(cmd, &ioctl_flags); |
1749 | if (!fn) { |
1750 | DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); |
1751 | return -ENOTTY; |
1752 | } |
1753 | |
1754 | /* |
1755 | * Copy the parameters into kernel space. |
1756 | */ |
1757 | r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags); |
1758 | |
1759 | if (r) |
1760 | return r; |
1761 | |
1762 | input_param_size = param->data_size; |
1763 | r = validate_params(cmd, param); |
1764 | if (r) |
1765 | goto out; |
1766 | |
1767 | param->data_size = sizeof(*param); |
1768 | r = fn(param, input_param_size); |
1769 | |
1770 | if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) && |
1771 | unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS)) |
1772 | DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd); |
1773 | |
1774 | /* |
1775 | * Copy the results back to userland. |
1776 | */ |
1777 | if (!r && copy_to_user(user, param, param->data_size)) |
1778 | r = -EFAULT; |
1779 | |
1780 | out: |
1781 | free_params(param, input_param_size, param_flags); |
1782 | return r; |
1783 | } |
1784 | |
1785 | static long dm_ctl_ioctl(struct file *file, uint command, ulong u) |
1786 | { |
1787 | return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u); |
1788 | } |
1789 | |
1790 | #ifdef CONFIG_COMPAT |
1791 | static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u) |
1792 | { |
1793 | return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u)); |
1794 | } |
1795 | #else |
1796 | #define dm_compat_ctl_ioctl NULL |
1797 | #endif |
1798 | |
1799 | static const struct file_operations _ctl_fops = { |
1800 | .open = nonseekable_open, |
1801 | .unlocked_ioctl = dm_ctl_ioctl, |
1802 | .compat_ioctl = dm_compat_ctl_ioctl, |
1803 | .owner = THIS_MODULE, |
1804 | .llseek = noop_llseek, |
1805 | }; |
1806 | |
1807 | static struct miscdevice _dm_misc = { |
1808 | .minor = MAPPER_CTRL_MINOR, |
1809 | .name = DM_NAME, |
1810 | .nodename = DM_DIR "/" DM_CONTROL_NODE, |
1811 | .fops = &_ctl_fops |
1812 | }; |
1813 | |
1814 | MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR); |
1815 | MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE); |
1816 | |
1817 | /* |
1818 | * Create misc character device and link to DM_DIR/control. |
1819 | */ |
1820 | int __init dm_interface_init(void) |
1821 | { |
1822 | int r; |
1823 | |
1824 | r = dm_hash_init(); |
1825 | if (r) |
1826 | return r; |
1827 | |
1828 | r = misc_register(&_dm_misc); |
1829 | if (r) { |
1830 | DMERR("misc_register failed for control device"); |
1831 | dm_hash_exit(); |
1832 | return r; |
1833 | } |
1834 | |
1835 | DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR, |
1836 | DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA, |
1837 | DM_DRIVER_EMAIL); |
1838 | return 0; |
1839 | } |
1840 | |
1841 | void dm_interface_exit(void) |
1842 | { |
1843 | if (misc_deregister(&_dm_misc) < 0) |
1844 | DMERR("misc_deregister failed for control device"); |
1845 | |
1846 | dm_hash_exit(); |
1847 | } |
1848 | |
1849 | /** |
1850 | * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers |
1851 | * @md: Pointer to mapped_device |
1852 | * @name: Buffer (size DM_NAME_LEN) for name |
1853 | * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined |
1854 | */ |
1855 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) |
1856 | { |
1857 | int r = 0; |
1858 | struct hash_cell *hc; |
1859 | |
1860 | if (!md) |
1861 | return -ENXIO; |
1862 | |
1863 | mutex_lock(&dm_hash_cells_mutex); |
1864 | hc = dm_get_mdptr(md); |
1865 | if (!hc || hc->md != md) { |
1866 | r = -ENXIO; |
1867 | goto out; |
1868 | } |
1869 | |
1870 | if (name) |
1871 | strcpy(name, hc->name); |
1872 | if (uuid) |
1873 | strcpy(uuid, hc->uuid ? : ""); |
1874 | |
1875 | out: |
1876 | mutex_unlock(&dm_hash_cells_mutex); |
1877 | |
1878 | return r; |
1879 | } |
1880 |
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