blob: 00cee02f8fc9b299788941c9b4147abdfc56c83c [file] [log] [blame]
Joe Thornber991d9fa2011-10-31 20:21:18 +00001/*
Joe Thornberda105ed2012-07-27 15:08:15 +01002 * Copyright (C) 2011-2012 Red Hat, Inc.
Joe Thornber991d9fa2011-10-31 20:21:18 +00003 *
4 * This file is released under the GPL.
5 */
6
7#include "dm-thin-metadata.h"
8#include "persistent-data/dm-btree.h"
9#include "persistent-data/dm-space-map.h"
10#include "persistent-data/dm-space-map-disk.h"
11#include "persistent-data/dm-transaction-manager.h"
12
13#include <linux/list.h>
14#include <linux/device-mapper.h>
15#include <linux/workqueue.h>
16
17/*--------------------------------------------------------------------------
18 * As far as the metadata goes, there is:
19 *
20 * - A superblock in block zero, taking up fewer than 512 bytes for
21 * atomic writes.
22 *
23 * - A space map managing the metadata blocks.
24 *
25 * - A space map managing the data blocks.
26 *
27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
28 *
29 * - A hierarchical btree, with 2 levels which effectively maps (thin
30 * dev id, virtual block) -> block_time. Block time is a 64-bit
31 * field holding the time in the low 24 bits, and block in the top 48
32 * bits.
33 *
34 * BTrees consist solely of btree_nodes, that fill a block. Some are
35 * internal nodes, as such their values are a __le64 pointing to other
36 * nodes. Leaf nodes can store data of any reasonable size (ie. much
37 * smaller than the block size). The nodes consist of the header,
38 * followed by an array of keys, followed by an array of values. We have
39 * to binary search on the keys so they're all held together to help the
40 * cpu cache.
41 *
42 * Space maps have 2 btrees:
43 *
44 * - One maps a uint64_t onto a struct index_entry. Which points to a
45 * bitmap block, and has some details about how many free entries there
46 * are etc.
47 *
48 * - The bitmap blocks have a header (for the checksum). Then the rest
49 * of the block is pairs of bits. With the meaning being:
50 *
51 * 0 - ref count is 0
52 * 1 - ref count is 1
53 * 2 - ref count is 2
54 * 3 - ref count is higher than 2
55 *
56 * - If the count is higher than 2 then the ref count is entered in a
57 * second btree that directly maps the block_address to a uint32_t ref
58 * count.
59 *
60 * The space map metadata variant doesn't have a bitmaps btree. Instead
61 * it has one single blocks worth of index_entries. This avoids
62 * recursive issues with the bitmap btree needing to allocate space in
63 * order to insert. With a small data block size such as 64k the
64 * metadata support data devices that are hundreds of terrabytes.
65 *
66 * The space maps allocate space linearly from front to back. Space that
67 * is freed in a transaction is never recycled within that transaction.
68 * To try and avoid fragmenting _free_ space the allocator always goes
69 * back and fills in gaps.
70 *
71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
72 * from the block manager.
73 *--------------------------------------------------------------------------*/
74
75#define DM_MSG_PREFIX "thin metadata"
76
77#define THIN_SUPERBLOCK_MAGIC 27022010
78#define THIN_SUPERBLOCK_LOCATION 0
79#define THIN_VERSION 1
80#define THIN_METADATA_CACHE_SIZE 64
81#define SECTOR_TO_BLOCK_SHIFT 3
82
Joe Thornber8c971172012-07-27 15:07:58 +010083/*
84 * 3 for btree insert +
85 * 2 for btree lookup used within space map
86 */
87#define THIN_MAX_CONCURRENT_LOCKS 5
88
Joe Thornber991d9fa2011-10-31 20:21:18 +000089/* This should be plenty */
90#define SPACE_MAP_ROOT_SIZE 128
91
92/*
93 * Little endian on-disk superblock and device details.
94 */
95struct thin_disk_superblock {
96 __le32 csum; /* Checksum of superblock except for this field. */
97 __le32 flags;
98 __le64 blocknr; /* This block number, dm_block_t. */
99
100 __u8 uuid[16];
101 __le64 magic;
102 __le32 version;
103 __le32 time;
104
105 __le64 trans_id;
106
107 /*
108 * Root held by userspace transactions.
109 */
110 __le64 held_root;
111
112 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
113 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
114
115 /*
116 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
117 */
118 __le64 data_mapping_root;
119
120 /*
121 * Device detail root mapping dev_id -> device_details
122 */
123 __le64 device_details_root;
124
125 __le32 data_block_size; /* In 512-byte sectors. */
126
127 __le32 metadata_block_size; /* In 512-byte sectors. */
128 __le64 metadata_nr_blocks;
129
130 __le32 compat_flags;
131 __le32 compat_ro_flags;
132 __le32 incompat_flags;
133} __packed;
134
135struct disk_device_details {
136 __le64 mapped_blocks;
137 __le64 transaction_id; /* When created. */
138 __le32 creation_time;
139 __le32 snapshotted_time;
140} __packed;
141
142struct dm_pool_metadata {
143 struct hlist_node hash;
144
145 struct block_device *bdev;
146 struct dm_block_manager *bm;
147 struct dm_space_map *metadata_sm;
148 struct dm_space_map *data_sm;
149 struct dm_transaction_manager *tm;
150 struct dm_transaction_manager *nb_tm;
151
152 /*
153 * Two-level btree.
154 * First level holds thin_dev_t.
155 * Second level holds mappings.
156 */
157 struct dm_btree_info info;
158
159 /*
160 * Non-blocking version of the above.
161 */
162 struct dm_btree_info nb_info;
163
164 /*
165 * Just the top level for deleting whole devices.
166 */
167 struct dm_btree_info tl_info;
168
169 /*
170 * Just the bottom level for creating new devices.
171 */
172 struct dm_btree_info bl_info;
173
174 /*
175 * Describes the device details btree.
176 */
177 struct dm_btree_info details_info;
178
179 struct rw_semaphore root_lock;
180 uint32_t time;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000181 dm_block_t root;
182 dm_block_t details_root;
183 struct list_head thin_devices;
184 uint64_t trans_id;
185 unsigned long flags;
186 sector_t data_block_size;
Joe Thornber12ba58a2012-07-27 15:08:15 +0100187 bool read_only:1;
Joe Thornberda105ed2012-07-27 15:08:15 +0100188
189 /*
190 * Set if a transaction has to be aborted but the attempt to roll back
191 * to the previous (good) transaction failed. The only pool metadata
192 * operation possible in this state is the closing of the device.
193 */
194 bool fail_io:1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000195};
196
197struct dm_thin_device {
198 struct list_head list;
199 struct dm_pool_metadata *pmd;
200 dm_thin_id id;
201
202 int open_count;
Joe Thornberda105ed2012-07-27 15:08:15 +0100203 bool changed:1;
204 bool aborted_with_changes:1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000205 uint64_t mapped_blocks;
206 uint64_t transaction_id;
207 uint32_t creation_time;
208 uint32_t snapshotted_time;
209};
210
211/*----------------------------------------------------------------
212 * superblock validator
213 *--------------------------------------------------------------*/
214
215#define SUPERBLOCK_CSUM_XOR 160774
216
217static void sb_prepare_for_write(struct dm_block_validator *v,
218 struct dm_block *b,
219 size_t block_size)
220{
221 struct thin_disk_superblock *disk_super = dm_block_data(b);
222
223 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
224 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
225 block_size - sizeof(__le32),
226 SUPERBLOCK_CSUM_XOR));
227}
228
229static int sb_check(struct dm_block_validator *v,
230 struct dm_block *b,
231 size_t block_size)
232{
233 struct thin_disk_superblock *disk_super = dm_block_data(b);
234 __le32 csum_le;
235
236 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
237 DMERR("sb_check failed: blocknr %llu: "
238 "wanted %llu", le64_to_cpu(disk_super->blocknr),
239 (unsigned long long)dm_block_location(b));
240 return -ENOTBLK;
241 }
242
243 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
244 DMERR("sb_check failed: magic %llu: "
245 "wanted %llu", le64_to_cpu(disk_super->magic),
246 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
247 return -EILSEQ;
248 }
249
250 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
251 block_size - sizeof(__le32),
252 SUPERBLOCK_CSUM_XOR));
253 if (csum_le != disk_super->csum) {
254 DMERR("sb_check failed: csum %u: wanted %u",
255 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
256 return -EILSEQ;
257 }
258
259 return 0;
260}
261
262static struct dm_block_validator sb_validator = {
263 .name = "superblock",
264 .prepare_for_write = sb_prepare_for_write,
265 .check = sb_check
266};
267
268/*----------------------------------------------------------------
269 * Methods for the btree value types
270 *--------------------------------------------------------------*/
271
272static uint64_t pack_block_time(dm_block_t b, uint32_t t)
273{
274 return (b << 24) | t;
275}
276
277static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
278{
279 *b = v >> 24;
280 *t = v & ((1 << 24) - 1);
281}
282
Mike Snitzer018cede2013-03-01 22:45:47 +0000283static void data_block_inc(void *context, const void *value_le)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000284{
285 struct dm_space_map *sm = context;
286 __le64 v_le;
287 uint64_t b;
288 uint32_t t;
289
290 memcpy(&v_le, value_le, sizeof(v_le));
291 unpack_block_time(le64_to_cpu(v_le), &b, &t);
292 dm_sm_inc_block(sm, b);
293}
294
Mike Snitzer018cede2013-03-01 22:45:47 +0000295static void data_block_dec(void *context, const void *value_le)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000296{
297 struct dm_space_map *sm = context;
298 __le64 v_le;
299 uint64_t b;
300 uint32_t t;
301
302 memcpy(&v_le, value_le, sizeof(v_le));
303 unpack_block_time(le64_to_cpu(v_le), &b, &t);
304 dm_sm_dec_block(sm, b);
305}
306
Mike Snitzer018cede2013-03-01 22:45:47 +0000307static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000308{
309 __le64 v1_le, v2_le;
310 uint64_t b1, b2;
311 uint32_t t;
312
313 memcpy(&v1_le, value1_le, sizeof(v1_le));
314 memcpy(&v2_le, value2_le, sizeof(v2_le));
315 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
316 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
317
318 return b1 == b2;
319}
320
Mike Snitzer018cede2013-03-01 22:45:47 +0000321static void subtree_inc(void *context, const void *value)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000322{
323 struct dm_btree_info *info = context;
324 __le64 root_le;
325 uint64_t root;
326
327 memcpy(&root_le, value, sizeof(root_le));
328 root = le64_to_cpu(root_le);
329 dm_tm_inc(info->tm, root);
330}
331
Mike Snitzer018cede2013-03-01 22:45:47 +0000332static void subtree_dec(void *context, const void *value)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000333{
334 struct dm_btree_info *info = context;
335 __le64 root_le;
336 uint64_t root;
337
338 memcpy(&root_le, value, sizeof(root_le));
339 root = le64_to_cpu(root_le);
340 if (dm_btree_del(info, root))
341 DMERR("btree delete failed\n");
342}
343
Mike Snitzer018cede2013-03-01 22:45:47 +0000344static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000345{
346 __le64 v1_le, v2_le;
347 memcpy(&v1_le, value1_le, sizeof(v1_le));
348 memcpy(&v2_le, value2_le, sizeof(v2_le));
349
350 return v1_le == v2_le;
351}
352
353/*----------------------------------------------------------------*/
354
Joe Thornber25971192012-07-27 15:08:09 +0100355static int superblock_lock_zero(struct dm_pool_metadata *pmd,
356 struct dm_block **sblock)
357{
358 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
359 &sb_validator, sblock);
360}
361
362static int superblock_lock(struct dm_pool_metadata *pmd,
363 struct dm_block **sblock)
364{
365 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
366 &sb_validator, sblock);
367}
368
Joe Thornber332627d2012-07-27 15:08:10 +0100369static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000370{
371 int r;
372 unsigned i;
373 struct dm_block *b;
374 __le64 *data_le, zero = cpu_to_le64(0);
375 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
376
377 /*
378 * We can't use a validator here - it may be all zeroes.
379 */
380 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
381 if (r)
382 return r;
383
384 data_le = dm_block_data(b);
385 *result = 1;
386 for (i = 0; i < block_size; i++) {
387 if (data_le[i] != zero) {
388 *result = 0;
389 break;
390 }
391 }
392
393 return dm_bm_unlock(b);
394}
395
Joe Thornber41675ae2012-07-27 15:08:08 +0100396static void __setup_btree_details(struct dm_pool_metadata *pmd)
397{
398 pmd->info.tm = pmd->tm;
399 pmd->info.levels = 2;
400 pmd->info.value_type.context = pmd->data_sm;
401 pmd->info.value_type.size = sizeof(__le64);
402 pmd->info.value_type.inc = data_block_inc;
403 pmd->info.value_type.dec = data_block_dec;
404 pmd->info.value_type.equal = data_block_equal;
405
406 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
407 pmd->nb_info.tm = pmd->nb_tm;
408
409 pmd->tl_info.tm = pmd->tm;
410 pmd->tl_info.levels = 1;
Joe Thornbere3cbf942012-12-21 20:23:32 +0000411 pmd->tl_info.value_type.context = &pmd->bl_info;
Joe Thornber41675ae2012-07-27 15:08:08 +0100412 pmd->tl_info.value_type.size = sizeof(__le64);
413 pmd->tl_info.value_type.inc = subtree_inc;
414 pmd->tl_info.value_type.dec = subtree_dec;
415 pmd->tl_info.value_type.equal = subtree_equal;
416
417 pmd->bl_info.tm = pmd->tm;
418 pmd->bl_info.levels = 1;
419 pmd->bl_info.value_type.context = pmd->data_sm;
420 pmd->bl_info.value_type.size = sizeof(__le64);
421 pmd->bl_info.value_type.inc = data_block_inc;
422 pmd->bl_info.value_type.dec = data_block_dec;
423 pmd->bl_info.value_type.equal = data_block_equal;
424
425 pmd->details_info.tm = pmd->tm;
426 pmd->details_info.levels = 1;
427 pmd->details_info.value_type.context = NULL;
428 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
429 pmd->details_info.value_type.inc = NULL;
430 pmd->details_info.value_type.dec = NULL;
431 pmd->details_info.value_type.equal = NULL;
432}
433
Joe Thornber9cb66532012-07-27 15:08:10 +0100434static int __write_initial_superblock(struct dm_pool_metadata *pmd)
435{
436 int r;
437 struct dm_block *sblock;
Joe Thornber10d2a9f2012-07-27 15:08:11 +0100438 size_t metadata_len, data_len;
Joe Thornber9cb66532012-07-27 15:08:10 +0100439 struct thin_disk_superblock *disk_super;
440 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
441
442 if (bdev_size > THIN_METADATA_MAX_SECTORS)
443 bdev_size = THIN_METADATA_MAX_SECTORS;
444
Joe Thornber10d2a9f2012-07-27 15:08:11 +0100445 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
446 if (r < 0)
447 return r;
448
449 r = dm_sm_root_size(pmd->data_sm, &data_len);
450 if (r < 0)
451 return r;
452
453 r = dm_sm_commit(pmd->data_sm);
454 if (r < 0)
455 return r;
456
457 r = dm_tm_pre_commit(pmd->tm);
458 if (r < 0)
459 return r;
460
Joe Thornber9cb66532012-07-27 15:08:10 +0100461 r = superblock_lock_zero(pmd, &sblock);
462 if (r)
463 return r;
464
465 disk_super = dm_block_data(sblock);
Joe Thornber10d2a9f2012-07-27 15:08:11 +0100466 disk_super->flags = 0;
Joe Thornber583ceee2012-07-27 15:08:11 +0100467 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
Joe Thornber9cb66532012-07-27 15:08:10 +0100468 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
469 disk_super->version = cpu_to_le32(THIN_VERSION);
470 disk_super->time = 0;
Joe Thornber10d2a9f2012-07-27 15:08:11 +0100471 disk_super->trans_id = 0;
472 disk_super->held_root = 0;
473
474 r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
475 metadata_len);
476 if (r < 0)
477 goto bad_locked;
478
479 r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
480 data_len);
481 if (r < 0)
482 goto bad_locked;
483
484 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
485 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
Joe Thornber9cb66532012-07-27 15:08:10 +0100486 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
487 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
488 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
489
Joe Thornber270938b2012-07-27 15:08:11 +0100490 return dm_tm_commit(pmd->tm, sblock);
Joe Thornber9cb66532012-07-27 15:08:10 +0100491
Joe Thornber10d2a9f2012-07-27 15:08:11 +0100492bad_locked:
493 dm_bm_unlock(sblock);
Joe Thornber9cb66532012-07-27 15:08:10 +0100494 return r;
495}
496
Joe Thornbera97e5e62012-07-27 15:08:12 +0100497static int __format_metadata(struct dm_pool_metadata *pmd)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000498{
499 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000500
Joe Thornbere4d22052012-07-27 15:08:12 +0100501 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
502 &pmd->tm, &pmd->metadata_sm);
503 if (r < 0) {
504 DMERR("tm_create_with_sm failed");
505 return r;
506 }
Joe Thornber991d9fa2011-10-31 20:21:18 +0000507
Joe Thornbera97e5e62012-07-27 15:08:12 +0100508 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
Joe Thornbere4d22052012-07-27 15:08:12 +0100509 if (IS_ERR(pmd->data_sm)) {
510 DMERR("sm_disk_create failed");
511 r = PTR_ERR(pmd->data_sm);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100512 goto bad_cleanup_tm;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000513 }
514
Joe Thornberd6332812012-07-27 15:08:12 +0100515 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000516 if (!pmd->nb_tm) {
Joe Thornber0fa5b172012-07-27 15:08:14 +0100517 DMERR("could not create non-blocking clone tm");
Joe Thornber991d9fa2011-10-31 20:21:18 +0000518 r = -ENOMEM;
Joe Thornber0fa5b172012-07-27 15:08:14 +0100519 goto bad_cleanup_data_sm;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000520 }
521
Joe Thornber41675ae2012-07-27 15:08:08 +0100522 __setup_btree_details(pmd);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000523
Joe Thornber9cb66532012-07-27 15:08:10 +0100524 r = dm_btree_empty(&pmd->info, &pmd->root);
525 if (r < 0)
Joe Thornber0fa5b172012-07-27 15:08:14 +0100526 goto bad_cleanup_nb_tm;
Joe Thornber9cb66532012-07-27 15:08:10 +0100527
528 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
529 if (r < 0) {
530 DMERR("couldn't create devices root");
Joe Thornber0fa5b172012-07-27 15:08:14 +0100531 goto bad_cleanup_nb_tm;
Joe Thornber9cb66532012-07-27 15:08:10 +0100532 }
533
534 r = __write_initial_superblock(pmd);
535 if (r)
Joe Thornber0fa5b172012-07-27 15:08:14 +0100536 goto bad_cleanup_nb_tm;
Joe Thornber9cb66532012-07-27 15:08:10 +0100537
Joe Thornber991d9fa2011-10-31 20:21:18 +0000538 return 0;
539
Joe Thornber0fa5b172012-07-27 15:08:14 +0100540bad_cleanup_nb_tm:
541 dm_tm_destroy(pmd->nb_tm);
542bad_cleanup_data_sm:
Joe Thornberd6332812012-07-27 15:08:12 +0100543 dm_sm_destroy(pmd->data_sm);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100544bad_cleanup_tm:
Joe Thornberd6332812012-07-27 15:08:12 +0100545 dm_tm_destroy(pmd->tm);
546 dm_sm_destroy(pmd->metadata_sm);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000547
548 return r;
549}
550
Mike Snitzerd73ec522012-07-27 15:08:13 +0100551static int __check_incompat_features(struct thin_disk_superblock *disk_super,
552 struct dm_pool_metadata *pmd)
553{
554 uint32_t features;
555
556 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
557 if (features) {
558 DMERR("could not access metadata due to unsupported optional features (%lx).",
559 (unsigned long)features);
560 return -EINVAL;
561 }
562
563 /*
564 * Check for read-only metadata to skip the following RDWR checks.
565 */
566 if (get_disk_ro(pmd->bdev->bd_disk))
567 return 0;
568
569 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
570 if (features) {
571 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
572 (unsigned long)features);
573 return -EINVAL;
574 }
575
576 return 0;
577}
578
Joe Thornbere4d22052012-07-27 15:08:12 +0100579static int __open_metadata(struct dm_pool_metadata *pmd)
580{
581 int r;
582 struct dm_block *sblock;
583 struct thin_disk_superblock *disk_super;
584
585 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
586 &sb_validator, &sblock);
587 if (r < 0) {
588 DMERR("couldn't read superblock");
589 return r;
590 }
591
592 disk_super = dm_block_data(sblock);
Mike Snitzerd73ec522012-07-27 15:08:13 +0100593
594 r = __check_incompat_features(disk_super, pmd);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100595 if (r < 0)
596 goto bad_unlock_sblock;
Mike Snitzerd73ec522012-07-27 15:08:13 +0100597
Joe Thornbere4d22052012-07-27 15:08:12 +0100598 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
599 disk_super->metadata_space_map_root,
600 sizeof(disk_super->metadata_space_map_root),
601 &pmd->tm, &pmd->metadata_sm);
602 if (r < 0) {
603 DMERR("tm_open_with_sm failed");
Joe Thornber0fa5b172012-07-27 15:08:14 +0100604 goto bad_unlock_sblock;
Joe Thornbere4d22052012-07-27 15:08:12 +0100605 }
606
607 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
608 sizeof(disk_super->data_space_map_root));
609 if (IS_ERR(pmd->data_sm)) {
610 DMERR("sm_disk_open failed");
Joe Thornbere4d22052012-07-27 15:08:12 +0100611 r = PTR_ERR(pmd->data_sm);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100612 goto bad_cleanup_tm;
Joe Thornbere4d22052012-07-27 15:08:12 +0100613 }
614
Joe Thornbere4d22052012-07-27 15:08:12 +0100615 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
616 if (!pmd->nb_tm) {
Joe Thornber0fa5b172012-07-27 15:08:14 +0100617 DMERR("could not create non-blocking clone tm");
Joe Thornbere4d22052012-07-27 15:08:12 +0100618 r = -ENOMEM;
Joe Thornber0fa5b172012-07-27 15:08:14 +0100619 goto bad_cleanup_data_sm;
Joe Thornbere4d22052012-07-27 15:08:12 +0100620 }
621
622 __setup_btree_details(pmd);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100623 return dm_bm_unlock(sblock);
Joe Thornbere4d22052012-07-27 15:08:12 +0100624
Joe Thornber0fa5b172012-07-27 15:08:14 +0100625bad_cleanup_data_sm:
Joe Thornbere4d22052012-07-27 15:08:12 +0100626 dm_sm_destroy(pmd->data_sm);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100627bad_cleanup_tm:
Joe Thornbere4d22052012-07-27 15:08:12 +0100628 dm_tm_destroy(pmd->tm);
629 dm_sm_destroy(pmd->metadata_sm);
Joe Thornber0fa5b172012-07-27 15:08:14 +0100630bad_unlock_sblock:
631 dm_bm_unlock(sblock);
Joe Thornbere4d22052012-07-27 15:08:12 +0100632
633 return r;
634}
635
Joe Thornber66b1edc2012-07-27 15:08:14 +0100636static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
Joe Thornbere4d22052012-07-27 15:08:12 +0100637{
Joe Thornber8801e062012-07-27 15:08:13 +0100638 int r, unformatted;
Joe Thornber237074c2012-07-27 15:08:13 +0100639
Joe Thornber8801e062012-07-27 15:08:13 +0100640 r = __superblock_all_zeroes(pmd->bm, &unformatted);
Joe Thornber237074c2012-07-27 15:08:13 +0100641 if (r)
642 return r;
643
Joe Thornber8801e062012-07-27 15:08:13 +0100644 if (unformatted)
Joe Thornber66b1edc2012-07-27 15:08:14 +0100645 return format_device ? __format_metadata(pmd) : -EPERM;
646
647 return __open_metadata(pmd);
Joe Thornbere4d22052012-07-27 15:08:12 +0100648}
649
Joe Thornber66b1edc2012-07-27 15:08:14 +0100650static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
Joe Thornber332627d2012-07-27 15:08:10 +0100651{
652 int r;
653
654 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE,
655 THIN_METADATA_CACHE_SIZE,
656 THIN_MAX_CONCURRENT_LOCKS);
657 if (IS_ERR(pmd->bm)) {
658 DMERR("could not create block manager");
659 return PTR_ERR(pmd->bm);
660 }
661
Joe Thornber66b1edc2012-07-27 15:08:14 +0100662 r = __open_or_format_metadata(pmd, format_device);
Joe Thornber332627d2012-07-27 15:08:10 +0100663 if (r)
664 dm_block_manager_destroy(pmd->bm);
665
666 return r;
667}
668
Joe Thornberf9dd9352012-07-27 15:08:10 +0100669static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
670{
671 dm_sm_destroy(pmd->data_sm);
672 dm_sm_destroy(pmd->metadata_sm);
673 dm_tm_destroy(pmd->nb_tm);
674 dm_tm_destroy(pmd->tm);
675 dm_block_manager_destroy(pmd->bm);
676}
677
Joe Thornber991d9fa2011-10-31 20:21:18 +0000678static int __begin_transaction(struct dm_pool_metadata *pmd)
679{
680 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000681 struct thin_disk_superblock *disk_super;
682 struct dm_block *sblock;
683
684 /*
Joe Thornber991d9fa2011-10-31 20:21:18 +0000685 * We re-read the superblock every time. Shouldn't need to do this
686 * really.
687 */
688 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
689 &sb_validator, &sblock);
690 if (r)
691 return r;
692
693 disk_super = dm_block_data(sblock);
694 pmd->time = le32_to_cpu(disk_super->time);
695 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
696 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
697 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
698 pmd->flags = le32_to_cpu(disk_super->flags);
699 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
700
Joe Thornber991d9fa2011-10-31 20:21:18 +0000701 dm_bm_unlock(sblock);
Mike Snitzerd73ec522012-07-27 15:08:13 +0100702 return 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000703}
704
705static int __write_changed_details(struct dm_pool_metadata *pmd)
706{
707 int r;
708 struct dm_thin_device *td, *tmp;
709 struct disk_device_details details;
710 uint64_t key;
711
712 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
713 if (!td->changed)
714 continue;
715
716 key = td->id;
717
718 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
719 details.transaction_id = cpu_to_le64(td->transaction_id);
720 details.creation_time = cpu_to_le32(td->creation_time);
721 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
722 __dm_bless_for_disk(&details);
723
724 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
725 &key, &details, &pmd->details_root);
726 if (r)
727 return r;
728
729 if (td->open_count)
730 td->changed = 0;
731 else {
732 list_del(&td->list);
733 kfree(td);
734 }
Joe Thornber991d9fa2011-10-31 20:21:18 +0000735 }
736
737 return 0;
738}
739
740static int __commit_transaction(struct dm_pool_metadata *pmd)
741{
Joe Thornber991d9fa2011-10-31 20:21:18 +0000742 int r;
743 size_t metadata_len, data_len;
744 struct thin_disk_superblock *disk_super;
745 struct dm_block *sblock;
746
747 /*
748 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
749 */
750 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
751
752 r = __write_changed_details(pmd);
753 if (r < 0)
Joe Thornberd973ac12012-07-27 15:07:58 +0100754 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000755
Joe Thornber991d9fa2011-10-31 20:21:18 +0000756 r = dm_sm_commit(pmd->data_sm);
757 if (r < 0)
Joe Thornberd973ac12012-07-27 15:07:58 +0100758 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000759
760 r = dm_tm_pre_commit(pmd->tm);
761 if (r < 0)
Joe Thornberd973ac12012-07-27 15:07:58 +0100762 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000763
764 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
765 if (r < 0)
Joe Thornberd973ac12012-07-27 15:07:58 +0100766 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000767
Joe Thornberfef838c2012-03-28 18:41:25 +0100768 r = dm_sm_root_size(pmd->data_sm, &data_len);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000769 if (r < 0)
Joe Thornberd973ac12012-07-27 15:07:58 +0100770 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000771
Joe Thornber25971192012-07-27 15:08:09 +0100772 r = superblock_lock(pmd, &sblock);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000773 if (r)
Joe Thornberd973ac12012-07-27 15:07:58 +0100774 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000775
776 disk_super = dm_block_data(sblock);
777 disk_super->time = cpu_to_le32(pmd->time);
778 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
779 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
780 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
781 disk_super->flags = cpu_to_le32(pmd->flags);
782
783 r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
784 metadata_len);
785 if (r < 0)
786 goto out_locked;
787
788 r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
789 data_len);
790 if (r < 0)
791 goto out_locked;
792
Joe Thornbereb04cf62012-07-27 15:08:08 +0100793 return dm_tm_commit(pmd->tm, sblock);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000794
795out_locked:
796 dm_bm_unlock(sblock);
797 return r;
798}
799
800struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
Joe Thornber66b1edc2012-07-27 15:08:14 +0100801 sector_t data_block_size,
802 bool format_device)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000803{
804 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000805 struct dm_pool_metadata *pmd;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000806
807 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
808 if (!pmd) {
809 DMERR("could not allocate metadata struct");
810 return ERR_PTR(-ENOMEM);
811 }
812
Joe Thornber6a0ebd32012-07-27 15:08:10 +0100813 init_rwsem(&pmd->root_lock);
814 pmd->time = 0;
815 INIT_LIST_HEAD(&pmd->thin_devices);
Joe Thornber12ba58a2012-07-27 15:08:15 +0100816 pmd->read_only = false;
Joe Thornberda105ed2012-07-27 15:08:15 +0100817 pmd->fail_io = false;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000818 pmd->bdev = bdev;
Joe Thornber9cb66532012-07-27 15:08:10 +0100819 pmd->data_block_size = data_block_size;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000820
Joe Thornber66b1edc2012-07-27 15:08:14 +0100821 r = __create_persistent_data_objects(pmd, format_device);
Joe Thornber332627d2012-07-27 15:08:10 +0100822 if (r) {
823 kfree(pmd);
824 return ERR_PTR(r);
825 }
826
Joe Thornber270938b2012-07-27 15:08:11 +0100827 r = __begin_transaction(pmd);
828 if (r < 0) {
829 if (dm_pool_metadata_close(pmd) < 0)
830 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
831 return ERR_PTR(r);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000832 }
833
834 return pmd;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000835}
836
837int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
838{
839 int r;
840 unsigned open_devices = 0;
841 struct dm_thin_device *td, *tmp;
842
843 down_read(&pmd->root_lock);
844 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
845 if (td->open_count)
846 open_devices++;
847 else {
848 list_del(&td->list);
849 kfree(td);
850 }
851 }
852 up_read(&pmd->root_lock);
853
854 if (open_devices) {
855 DMERR("attempt to close pmd when %u device(s) are still open",
856 open_devices);
857 return -EBUSY;
858 }
859
Joe Thornberda105ed2012-07-27 15:08:15 +0100860 if (!pmd->read_only && !pmd->fail_io) {
Joe Thornber12ba58a2012-07-27 15:08:15 +0100861 r = __commit_transaction(pmd);
862 if (r < 0)
863 DMWARN("%s: __commit_transaction() failed, error = %d",
864 __func__, r);
865 }
Joe Thornber991d9fa2011-10-31 20:21:18 +0000866
Joe Thornberda105ed2012-07-27 15:08:15 +0100867 if (!pmd->fail_io)
868 __destroy_persistent_data_objects(pmd);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000869
Joe Thornberda105ed2012-07-27 15:08:15 +0100870 kfree(pmd);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000871 return 0;
872}
873
Mike Snitzer1f3db252012-03-07 19:09:41 +0000874/*
875 * __open_device: Returns @td corresponding to device with id @dev,
876 * creating it if @create is set and incrementing @td->open_count.
877 * On failure, @td is undefined.
878 */
Joe Thornber991d9fa2011-10-31 20:21:18 +0000879static int __open_device(struct dm_pool_metadata *pmd,
880 dm_thin_id dev, int create,
881 struct dm_thin_device **td)
882{
883 int r, changed = 0;
884 struct dm_thin_device *td2;
885 uint64_t key = dev;
886 struct disk_device_details details_le;
887
888 /*
Mike Snitzer1f3db252012-03-07 19:09:41 +0000889 * If the device is already open, return it.
Joe Thornber991d9fa2011-10-31 20:21:18 +0000890 */
891 list_for_each_entry(td2, &pmd->thin_devices, list)
892 if (td2->id == dev) {
Mike Snitzer1f3db252012-03-07 19:09:41 +0000893 /*
894 * May not create an already-open device.
895 */
896 if (create)
897 return -EEXIST;
898
Joe Thornber991d9fa2011-10-31 20:21:18 +0000899 td2->open_count++;
900 *td = td2;
901 return 0;
902 }
903
904 /*
905 * Check the device exists.
906 */
907 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
908 &key, &details_le);
909 if (r) {
910 if (r != -ENODATA || !create)
911 return r;
912
Mike Snitzer1f3db252012-03-07 19:09:41 +0000913 /*
914 * Create new device.
915 */
Joe Thornber991d9fa2011-10-31 20:21:18 +0000916 changed = 1;
917 details_le.mapped_blocks = 0;
918 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
919 details_le.creation_time = cpu_to_le32(pmd->time);
920 details_le.snapshotted_time = cpu_to_le32(pmd->time);
921 }
922
923 *td = kmalloc(sizeof(**td), GFP_NOIO);
924 if (!*td)
925 return -ENOMEM;
926
927 (*td)->pmd = pmd;
928 (*td)->id = dev;
929 (*td)->open_count = 1;
930 (*td)->changed = changed;
Joe Thornberda105ed2012-07-27 15:08:15 +0100931 (*td)->aborted_with_changes = false;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000932 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
933 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
934 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
935 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
936
937 list_add(&(*td)->list, &pmd->thin_devices);
938
939 return 0;
940}
941
942static void __close_device(struct dm_thin_device *td)
943{
944 --td->open_count;
945}
946
947static int __create_thin(struct dm_pool_metadata *pmd,
948 dm_thin_id dev)
949{
950 int r;
951 dm_block_t dev_root;
952 uint64_t key = dev;
953 struct disk_device_details details_le;
954 struct dm_thin_device *td;
955 __le64 value;
956
957 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
958 &key, &details_le);
959 if (!r)
960 return -EEXIST;
961
962 /*
963 * Create an empty btree for the mappings.
964 */
965 r = dm_btree_empty(&pmd->bl_info, &dev_root);
966 if (r)
967 return r;
968
969 /*
970 * Insert it into the main mapping tree.
971 */
972 value = cpu_to_le64(dev_root);
973 __dm_bless_for_disk(&value);
974 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
975 if (r) {
976 dm_btree_del(&pmd->bl_info, dev_root);
977 return r;
978 }
979
980 r = __open_device(pmd, dev, 1, &td);
981 if (r) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000982 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
983 dm_btree_del(&pmd->bl_info, dev_root);
984 return r;
985 }
Joe Thornber991d9fa2011-10-31 20:21:18 +0000986 __close_device(td);
987
988 return r;
989}
990
991int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
992{
Joe Thornberda105ed2012-07-27 15:08:15 +0100993 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000994
995 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +0100996 if (!pmd->fail_io)
997 r = __create_thin(pmd, dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000998 up_write(&pmd->root_lock);
999
1000 return r;
1001}
1002
1003static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1004 struct dm_thin_device *snap,
1005 dm_thin_id origin, uint32_t time)
1006{
1007 int r;
1008 struct dm_thin_device *td;
1009
1010 r = __open_device(pmd, origin, 0, &td);
1011 if (r)
1012 return r;
1013
1014 td->changed = 1;
1015 td->snapshotted_time = time;
1016
1017 snap->mapped_blocks = td->mapped_blocks;
1018 snap->snapshotted_time = time;
1019 __close_device(td);
1020
1021 return 0;
1022}
1023
1024static int __create_snap(struct dm_pool_metadata *pmd,
1025 dm_thin_id dev, dm_thin_id origin)
1026{
1027 int r;
1028 dm_block_t origin_root;
1029 uint64_t key = origin, dev_key = dev;
1030 struct dm_thin_device *td;
1031 struct disk_device_details details_le;
1032 __le64 value;
1033
1034 /* check this device is unused */
1035 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1036 &dev_key, &details_le);
1037 if (!r)
1038 return -EEXIST;
1039
1040 /* find the mapping tree for the origin */
1041 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1042 if (r)
1043 return r;
1044 origin_root = le64_to_cpu(value);
1045
1046 /* clone the origin, an inc will do */
1047 dm_tm_inc(pmd->tm, origin_root);
1048
1049 /* insert into the main mapping tree */
1050 value = cpu_to_le64(origin_root);
1051 __dm_bless_for_disk(&value);
1052 key = dev;
1053 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1054 if (r) {
1055 dm_tm_dec(pmd->tm, origin_root);
1056 return r;
1057 }
1058
1059 pmd->time++;
1060
1061 r = __open_device(pmd, dev, 1, &td);
1062 if (r)
1063 goto bad;
1064
1065 r = __set_snapshot_details(pmd, td, origin, pmd->time);
Mike Snitzer1f3db252012-03-07 19:09:41 +00001066 __close_device(td);
1067
Joe Thornber991d9fa2011-10-31 20:21:18 +00001068 if (r)
1069 goto bad;
1070
Joe Thornber991d9fa2011-10-31 20:21:18 +00001071 return 0;
1072
1073bad:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001074 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1075 dm_btree_remove(&pmd->details_info, pmd->details_root,
1076 &key, &pmd->details_root);
1077 return r;
1078}
1079
1080int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1081 dm_thin_id dev,
1082 dm_thin_id origin)
1083{
Joe Thornberda105ed2012-07-27 15:08:15 +01001084 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001085
1086 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001087 if (!pmd->fail_io)
1088 r = __create_snap(pmd, dev, origin);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001089 up_write(&pmd->root_lock);
1090
1091 return r;
1092}
1093
1094static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1095{
1096 int r;
1097 uint64_t key = dev;
1098 struct dm_thin_device *td;
1099
1100 /* TODO: failure should mark the transaction invalid */
1101 r = __open_device(pmd, dev, 0, &td);
1102 if (r)
1103 return r;
1104
1105 if (td->open_count > 1) {
1106 __close_device(td);
1107 return -EBUSY;
1108 }
1109
1110 list_del(&td->list);
1111 kfree(td);
1112 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1113 &key, &pmd->details_root);
1114 if (r)
1115 return r;
1116
1117 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1118 if (r)
1119 return r;
1120
Joe Thornber991d9fa2011-10-31 20:21:18 +00001121 return 0;
1122}
1123
1124int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1125 dm_thin_id dev)
1126{
Joe Thornberda105ed2012-07-27 15:08:15 +01001127 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001128
1129 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001130 if (!pmd->fail_io)
1131 r = __delete_device(pmd, dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001132 up_write(&pmd->root_lock);
1133
1134 return r;
1135}
1136
1137int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1138 uint64_t current_id,
1139 uint64_t new_id)
1140{
Joe Thornberda105ed2012-07-27 15:08:15 +01001141 int r = -EINVAL;
1142
Joe Thornber991d9fa2011-10-31 20:21:18 +00001143 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001144
1145 if (pmd->fail_io)
1146 goto out;
1147
Joe Thornber991d9fa2011-10-31 20:21:18 +00001148 if (pmd->trans_id != current_id) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001149 DMERR("mismatched transaction id");
Joe Thornberda105ed2012-07-27 15:08:15 +01001150 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001151 }
1152
1153 pmd->trans_id = new_id;
Joe Thornberda105ed2012-07-27 15:08:15 +01001154 r = 0;
1155
1156out:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001157 up_write(&pmd->root_lock);
1158
Joe Thornberda105ed2012-07-27 15:08:15 +01001159 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001160}
1161
1162int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1163 uint64_t *result)
1164{
Joe Thornberda105ed2012-07-27 15:08:15 +01001165 int r = -EINVAL;
1166
Joe Thornber991d9fa2011-10-31 20:21:18 +00001167 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001168 if (!pmd->fail_io) {
1169 *result = pmd->trans_id;
1170 r = 0;
1171 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001172 up_read(&pmd->root_lock);
1173
Joe Thornberda105ed2012-07-27 15:08:15 +01001174 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001175}
1176
Joe Thornbercc8394d2012-06-03 00:30:01 +01001177static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1178{
1179 int r, inc;
1180 struct thin_disk_superblock *disk_super;
1181 struct dm_block *copy, *sblock;
1182 dm_block_t held_root;
1183
1184 /*
1185 * Copy the superblock.
1186 */
1187 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1188 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1189 &sb_validator, &copy, &inc);
1190 if (r)
1191 return r;
1192
1193 BUG_ON(!inc);
1194
1195 held_root = dm_block_location(copy);
1196 disk_super = dm_block_data(copy);
1197
1198 if (le64_to_cpu(disk_super->held_root)) {
1199 DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1200
1201 dm_tm_dec(pmd->tm, held_root);
1202 dm_tm_unlock(pmd->tm, copy);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001203 return -EBUSY;
1204 }
1205
1206 /*
1207 * Wipe the spacemap since we're not publishing this.
1208 */
1209 memset(&disk_super->data_space_map_root, 0,
1210 sizeof(disk_super->data_space_map_root));
1211 memset(&disk_super->metadata_space_map_root, 0,
1212 sizeof(disk_super->metadata_space_map_root));
1213
1214 /*
1215 * Increment the data structures that need to be preserved.
1216 */
1217 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1218 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1219 dm_tm_unlock(pmd->tm, copy);
1220
1221 /*
1222 * Write the held root into the superblock.
1223 */
Joe Thornber25971192012-07-27 15:08:09 +01001224 r = superblock_lock(pmd, &sblock);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001225 if (r) {
1226 dm_tm_dec(pmd->tm, held_root);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001227 return r;
1228 }
1229
1230 disk_super = dm_block_data(sblock);
1231 disk_super->held_root = cpu_to_le64(held_root);
1232 dm_bm_unlock(sblock);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001233 return 0;
1234}
1235
1236int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1237{
Joe Thornberda105ed2012-07-27 15:08:15 +01001238 int r = -EINVAL;
Joe Thornbercc8394d2012-06-03 00:30:01 +01001239
1240 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001241 if (!pmd->fail_io)
1242 r = __reserve_metadata_snap(pmd);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001243 up_write(&pmd->root_lock);
1244
1245 return r;
1246}
1247
1248static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1249{
1250 int r;
1251 struct thin_disk_superblock *disk_super;
1252 struct dm_block *sblock, *copy;
1253 dm_block_t held_root;
1254
Joe Thornber25971192012-07-27 15:08:09 +01001255 r = superblock_lock(pmd, &sblock);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001256 if (r)
1257 return r;
1258
1259 disk_super = dm_block_data(sblock);
1260 held_root = le64_to_cpu(disk_super->held_root);
1261 disk_super->held_root = cpu_to_le64(0);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001262
1263 dm_bm_unlock(sblock);
1264
1265 if (!held_root) {
1266 DMWARN("No pool metadata snapshot found: nothing to release.");
1267 return -EINVAL;
1268 }
1269
1270 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
1271 if (r)
1272 return r;
1273
1274 disk_super = dm_block_data(copy);
1275 dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->data_mapping_root));
1276 dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->device_details_root));
1277 dm_sm_dec_block(pmd->metadata_sm, held_root);
1278
1279 return dm_tm_unlock(pmd->tm, copy);
1280}
1281
1282int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1283{
Joe Thornberda105ed2012-07-27 15:08:15 +01001284 int r = -EINVAL;
Joe Thornbercc8394d2012-06-03 00:30:01 +01001285
1286 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001287 if (!pmd->fail_io)
1288 r = __release_metadata_snap(pmd);
Joe Thornbercc8394d2012-06-03 00:30:01 +01001289 up_write(&pmd->root_lock);
1290
1291 return r;
1292}
1293
1294static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1295 dm_block_t *result)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001296{
1297 int r;
1298 struct thin_disk_superblock *disk_super;
1299 struct dm_block *sblock;
1300
Joe Thornbercc8394d2012-06-03 00:30:01 +01001301 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1302 &sb_validator, &sblock);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001303 if (r)
1304 return r;
1305
1306 disk_super = dm_block_data(sblock);
1307 *result = le64_to_cpu(disk_super->held_root);
1308
1309 return dm_bm_unlock(sblock);
1310}
1311
Joe Thornbercc8394d2012-06-03 00:30:01 +01001312int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1313 dm_block_t *result)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001314{
Joe Thornberda105ed2012-07-27 15:08:15 +01001315 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001316
1317 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001318 if (!pmd->fail_io)
1319 r = __get_metadata_snap(pmd, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001320 up_read(&pmd->root_lock);
1321
1322 return r;
1323}
1324
1325int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1326 struct dm_thin_device **td)
1327{
Joe Thornberda105ed2012-07-27 15:08:15 +01001328 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001329
1330 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001331 if (!pmd->fail_io)
1332 r = __open_device(pmd, dev, 0, td);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001333 up_write(&pmd->root_lock);
1334
1335 return r;
1336}
1337
1338int dm_pool_close_thin_device(struct dm_thin_device *td)
1339{
1340 down_write(&td->pmd->root_lock);
1341 __close_device(td);
1342 up_write(&td->pmd->root_lock);
1343
1344 return 0;
1345}
1346
1347dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1348{
1349 return td->id;
1350}
1351
Mike Snitzer17b7d632012-07-27 15:07:57 +01001352static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001353{
1354 return td->snapshotted_time > time;
1355}
1356
1357int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1358 int can_block, struct dm_thin_lookup_result *result)
1359{
Joe Thornberda105ed2012-07-27 15:08:15 +01001360 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001361 uint64_t block_time = 0;
1362 __le64 value;
1363 struct dm_pool_metadata *pmd = td->pmd;
1364 dm_block_t keys[2] = { td->id, block };
Joe Thornberda105ed2012-07-27 15:08:15 +01001365 struct dm_btree_info *info;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001366
1367 if (can_block) {
1368 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001369 info = &pmd->info;
1370 } else if (down_read_trylock(&pmd->root_lock))
1371 info = &pmd->nb_info;
1372 else
Joe Thornber991d9fa2011-10-31 20:21:18 +00001373 return -EWOULDBLOCK;
1374
Joe Thornberda105ed2012-07-27 15:08:15 +01001375 if (pmd->fail_io)
1376 goto out;
1377
1378 r = dm_btree_lookup(info, pmd->root, keys, &value);
1379 if (!r)
1380 block_time = le64_to_cpu(value);
1381
1382out:
1383 up_read(&pmd->root_lock);
1384
Joe Thornber991d9fa2011-10-31 20:21:18 +00001385 if (!r) {
1386 dm_block_t exception_block;
1387 uint32_t exception_time;
1388 unpack_block_time(block_time, &exception_block,
1389 &exception_time);
1390 result->block = exception_block;
1391 result->shared = __snapshotted_since(td, exception_time);
1392 }
1393
1394 return r;
1395}
1396
1397static int __insert(struct dm_thin_device *td, dm_block_t block,
1398 dm_block_t data_block)
1399{
1400 int r, inserted;
1401 __le64 value;
1402 struct dm_pool_metadata *pmd = td->pmd;
1403 dm_block_t keys[2] = { td->id, block };
1404
Joe Thornber991d9fa2011-10-31 20:21:18 +00001405 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1406 __dm_bless_for_disk(&value);
1407
1408 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1409 &pmd->root, &inserted);
1410 if (r)
1411 return r;
1412
Joe Thornber40db5a52012-07-27 15:08:14 +01001413 td->changed = 1;
1414 if (inserted)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001415 td->mapped_blocks++;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001416
1417 return 0;
1418}
1419
1420int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1421 dm_block_t data_block)
1422{
Joe Thornberda105ed2012-07-27 15:08:15 +01001423 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001424
1425 down_write(&td->pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001426 if (!td->pmd->fail_io)
1427 r = __insert(td, block, data_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001428 up_write(&td->pmd->root_lock);
1429
1430 return r;
1431}
1432
1433static int __remove(struct dm_thin_device *td, dm_block_t block)
1434{
1435 int r;
1436 struct dm_pool_metadata *pmd = td->pmd;
1437 dm_block_t keys[2] = { td->id, block };
1438
1439 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1440 if (r)
1441 return r;
1442
Joe Thornberaf63bcb2012-03-07 19:09:44 +00001443 td->mapped_blocks--;
1444 td->changed = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001445
1446 return 0;
1447}
1448
1449int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1450{
Joe Thornberda105ed2012-07-27 15:08:15 +01001451 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001452
1453 down_write(&td->pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001454 if (!td->pmd->fail_io)
1455 r = __remove(td, block);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001456 up_write(&td->pmd->root_lock);
1457
1458 return r;
1459}
1460
Joe Thornber40db5a52012-07-27 15:08:14 +01001461bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1462{
1463 int r;
1464
1465 down_read(&td->pmd->root_lock);
1466 r = td->changed;
1467 up_read(&td->pmd->root_lock);
1468
1469 return r;
1470}
1471
Joe Thornberda105ed2012-07-27 15:08:15 +01001472bool dm_thin_aborted_changes(struct dm_thin_device *td)
1473{
1474 bool r;
1475
1476 down_read(&td->pmd->root_lock);
1477 r = td->aborted_with_changes;
1478 up_read(&td->pmd->root_lock);
1479
1480 return r;
1481}
1482
Joe Thornber991d9fa2011-10-31 20:21:18 +00001483int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1484{
Joe Thornberda105ed2012-07-27 15:08:15 +01001485 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001486
1487 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001488 if (!pmd->fail_io)
1489 r = dm_sm_new_block(pmd->data_sm, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001490 up_write(&pmd->root_lock);
1491
1492 return r;
1493}
1494
1495int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1496{
Joe Thornberda105ed2012-07-27 15:08:15 +01001497 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001498
1499 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001500 if (pmd->fail_io)
1501 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001502
1503 r = __commit_transaction(pmd);
1504 if (r <= 0)
1505 goto out;
1506
1507 /*
1508 * Open the next transaction.
1509 */
1510 r = __begin_transaction(pmd);
1511out:
1512 up_write(&pmd->root_lock);
1513 return r;
1514}
1515
Joe Thornberda105ed2012-07-27 15:08:15 +01001516static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1517{
1518 struct dm_thin_device *td;
1519
1520 list_for_each_entry(td, &pmd->thin_devices, list)
1521 td->aborted_with_changes = td->changed;
1522}
1523
1524int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1525{
1526 int r = -EINVAL;
1527
1528 down_write(&pmd->root_lock);
1529 if (pmd->fail_io)
1530 goto out;
1531
1532 __set_abort_with_changes_flags(pmd);
1533 __destroy_persistent_data_objects(pmd);
1534 r = __create_persistent_data_objects(pmd, false);
1535 if (r)
1536 pmd->fail_io = true;
1537
1538out:
1539 up_write(&pmd->root_lock);
1540
1541 return r;
1542}
1543
Joe Thornber991d9fa2011-10-31 20:21:18 +00001544int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1545{
Joe Thornberda105ed2012-07-27 15:08:15 +01001546 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001547
1548 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001549 if (!pmd->fail_io)
1550 r = dm_sm_get_nr_free(pmd->data_sm, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001551 up_read(&pmd->root_lock);
1552
1553 return r;
1554}
1555
1556int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1557 dm_block_t *result)
1558{
Joe Thornberda105ed2012-07-27 15:08:15 +01001559 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001560
1561 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001562 if (!pmd->fail_io)
1563 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001564 up_read(&pmd->root_lock);
1565
1566 return r;
1567}
1568
1569int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1570 dm_block_t *result)
1571{
Joe Thornberda105ed2012-07-27 15:08:15 +01001572 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001573
1574 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001575 if (!pmd->fail_io)
1576 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001577 up_read(&pmd->root_lock);
1578
1579 return r;
1580}
1581
1582int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result)
1583{
1584 down_read(&pmd->root_lock);
1585 *result = pmd->data_block_size;
1586 up_read(&pmd->root_lock);
1587
1588 return 0;
1589}
1590
1591int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1592{
Joe Thornberda105ed2012-07-27 15:08:15 +01001593 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001594
1595 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001596 if (!pmd->fail_io)
1597 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001598 up_read(&pmd->root_lock);
1599
1600 return r;
1601}
1602
1603int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1604{
Joe Thornberda105ed2012-07-27 15:08:15 +01001605 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001606 struct dm_pool_metadata *pmd = td->pmd;
1607
1608 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001609 if (!pmd->fail_io) {
1610 *result = td->mapped_blocks;
1611 r = 0;
1612 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001613 up_read(&pmd->root_lock);
1614
Joe Thornberda105ed2012-07-27 15:08:15 +01001615 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001616}
1617
1618static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1619{
1620 int r;
1621 __le64 value_le;
1622 dm_block_t thin_root;
1623 struct dm_pool_metadata *pmd = td->pmd;
1624
1625 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1626 if (r)
1627 return r;
1628
1629 thin_root = le64_to_cpu(value_le);
1630
1631 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1632}
1633
1634int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1635 dm_block_t *result)
1636{
Joe Thornberda105ed2012-07-27 15:08:15 +01001637 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001638 struct dm_pool_metadata *pmd = td->pmd;
1639
1640 down_read(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001641 if (!pmd->fail_io)
1642 r = __highest_block(td, result);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001643 up_read(&pmd->root_lock);
1644
1645 return r;
1646}
1647
1648static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1649{
1650 int r;
1651 dm_block_t old_count;
1652
1653 r = dm_sm_get_nr_blocks(pmd->data_sm, &old_count);
1654 if (r)
1655 return r;
1656
1657 if (new_count == old_count)
1658 return 0;
1659
1660 if (new_count < old_count) {
1661 DMERR("cannot reduce size of data device");
1662 return -EINVAL;
1663 }
1664
Joe Thornbereb04cf62012-07-27 15:08:08 +01001665 return dm_sm_extend(pmd->data_sm, new_count - old_count);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001666}
1667
1668int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1669{
Joe Thornberda105ed2012-07-27 15:08:15 +01001670 int r = -EINVAL;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001671
1672 down_write(&pmd->root_lock);
Joe Thornberda105ed2012-07-27 15:08:15 +01001673 if (!pmd->fail_io)
1674 r = __resize_data_dev(pmd, new_count);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001675 up_write(&pmd->root_lock);
1676
1677 return r;
1678}
Joe Thornber12ba58a2012-07-27 15:08:15 +01001679
1680void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1681{
1682 down_write(&pmd->root_lock);
1683 pmd->read_only = true;
1684 dm_bm_set_read_only(pmd->bm);
1685 up_write(&pmd->root_lock);
1686}