2 * Copyright (C) 2011 Red Hat, Inc.
4 * This file is released under the GPL.
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"
13 #include <linux/list.h>
14 #include <linux/device-mapper.h>
15 #include <linux/workqueue.h>
17 /*--------------------------------------------------------------------------
18 * As far as the metadata goes, there is:
20 * - A superblock in block zero, taking up fewer than 512 bytes for
23 * - A space map managing the metadata blocks.
25 * - A space map managing the data blocks.
27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
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
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
42 * Space maps have 2 btrees:
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
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:
54 * 3 - ref count is higher than 2
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
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.
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.
71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
72 * from the block manager.
73 *--------------------------------------------------------------------------*/
75 #define DM_MSG_PREFIX "thin metadata"
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
84 * 3 for btree insert +
85 * 2 for btree lookup used within space map
87 #define THIN_MAX_CONCURRENT_LOCKS 5
89 /* This should be plenty */
90 #define SPACE_MAP_ROOT_SIZE 128
93 * Little endian on-disk superblock and device details.
95 struct thin_disk_superblock {
96 __le32 csum; /* Checksum of superblock except for this field. */
98 __le64 blocknr; /* This block number, dm_block_t. */
108 * Root held by userspace transactions.
112 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
113 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
116 * 2-level btree mapping (dev_id, (dev block, time)) -> data block
118 __le64 data_mapping_root;
121 * Device detail root mapping dev_id -> device_details
123 __le64 device_details_root;
125 __le32 data_block_size; /* In 512-byte sectors. */
127 __le32 metadata_block_size; /* In 512-byte sectors. */
128 __le64 metadata_nr_blocks;
131 __le32 compat_ro_flags;
132 __le32 incompat_flags;
135 struct disk_device_details {
136 __le64 mapped_blocks;
137 __le64 transaction_id; /* When created. */
138 __le32 creation_time;
139 __le32 snapshotted_time;
142 struct dm_pool_metadata {
143 struct hlist_node hash;
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;
154 * First level holds thin_dev_t.
155 * Second level holds mappings.
157 struct dm_btree_info info;
160 * Non-blocking version of the above.
162 struct dm_btree_info nb_info;
165 * Just the top level for deleting whole devices.
167 struct dm_btree_info tl_info;
170 * Just the bottom level for creating new devices.
172 struct dm_btree_info bl_info;
175 * Describes the device details btree.
177 struct dm_btree_info details_info;
179 struct rw_semaphore root_lock;
183 dm_block_t details_root;
184 struct list_head thin_devices;
187 sector_t data_block_size;
190 struct dm_thin_device {
191 struct list_head list;
192 struct dm_pool_metadata *pmd;
197 uint64_t mapped_blocks;
198 uint64_t transaction_id;
199 uint32_t creation_time;
200 uint32_t snapshotted_time;
203 /*----------------------------------------------------------------
204 * superblock validator
205 *--------------------------------------------------------------*/
207 #define SUPERBLOCK_CSUM_XOR 160774
209 static void sb_prepare_for_write(struct dm_block_validator *v,
213 struct thin_disk_superblock *disk_super = dm_block_data(b);
215 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
216 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
217 block_size - sizeof(__le32),
218 SUPERBLOCK_CSUM_XOR));
221 static int sb_check(struct dm_block_validator *v,
225 struct thin_disk_superblock *disk_super = dm_block_data(b);
228 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
229 DMERR("sb_check failed: blocknr %llu: "
230 "wanted %llu", le64_to_cpu(disk_super->blocknr),
231 (unsigned long long)dm_block_location(b));
235 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
236 DMERR("sb_check failed: magic %llu: "
237 "wanted %llu", le64_to_cpu(disk_super->magic),
238 (unsigned long long)THIN_SUPERBLOCK_MAGIC);
242 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
243 block_size - sizeof(__le32),
244 SUPERBLOCK_CSUM_XOR));
245 if (csum_le != disk_super->csum) {
246 DMERR("sb_check failed: csum %u: wanted %u",
247 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
254 static struct dm_block_validator sb_validator = {
255 .name = "superblock",
256 .prepare_for_write = sb_prepare_for_write,
260 /*----------------------------------------------------------------
261 * Methods for the btree value types
262 *--------------------------------------------------------------*/
264 static uint64_t pack_block_time(dm_block_t b, uint32_t t)
266 return (b << 24) | t;
269 static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
272 *t = v & ((1 << 24) - 1);
275 static void data_block_inc(void *context, void *value_le)
277 struct dm_space_map *sm = context;
282 memcpy(&v_le, value_le, sizeof(v_le));
283 unpack_block_time(le64_to_cpu(v_le), &b, &t);
284 dm_sm_inc_block(sm, b);
287 static void data_block_dec(void *context, void *value_le)
289 struct dm_space_map *sm = context;
294 memcpy(&v_le, value_le, sizeof(v_le));
295 unpack_block_time(le64_to_cpu(v_le), &b, &t);
296 dm_sm_dec_block(sm, b);
299 static int data_block_equal(void *context, void *value1_le, void *value2_le)
305 memcpy(&v1_le, value1_le, sizeof(v1_le));
306 memcpy(&v2_le, value2_le, sizeof(v2_le));
307 unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
308 unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
313 static void subtree_inc(void *context, void *value)
315 struct dm_btree_info *info = context;
319 memcpy(&root_le, value, sizeof(root_le));
320 root = le64_to_cpu(root_le);
321 dm_tm_inc(info->tm, root);
324 static void subtree_dec(void *context, void *value)
326 struct dm_btree_info *info = context;
330 memcpy(&root_le, value, sizeof(root_le));
331 root = le64_to_cpu(root_le);
332 if (dm_btree_del(info, root))
333 DMERR("btree delete failed\n");
336 static int subtree_equal(void *context, void *value1_le, void *value2_le)
339 memcpy(&v1_le, value1_le, sizeof(v1_le));
340 memcpy(&v2_le, value2_le, sizeof(v2_le));
342 return v1_le == v2_le;
345 /*----------------------------------------------------------------*/
347 static int superblock_all_zeroes(struct dm_block_manager *bm, int *result)
352 __le64 *data_le, zero = cpu_to_le64(0);
353 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
356 * We can't use a validator here - it may be all zeroes.
358 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
362 data_le = dm_block_data(b);
364 for (i = 0; i < block_size; i++) {
365 if (data_le[i] != zero) {
371 return dm_bm_unlock(b);
374 static int init_pmd(struct dm_pool_metadata *pmd,
375 struct dm_block_manager *bm,
376 dm_block_t nr_blocks, int create)
379 struct dm_space_map *sm, *data_sm;
380 struct dm_transaction_manager *tm;
381 struct dm_block *sblock;
384 r = dm_tm_create_with_sm(bm, THIN_SUPERBLOCK_LOCATION,
385 &sb_validator, &tm, &sm, &sblock);
387 DMERR("tm_create_with_sm failed");
391 data_sm = dm_sm_disk_create(tm, nr_blocks);
392 if (IS_ERR(data_sm)) {
393 DMERR("sm_disk_create failed");
394 dm_tm_unlock(tm, sblock);
395 r = PTR_ERR(data_sm);
399 struct thin_disk_superblock *disk_super = NULL;
400 size_t space_map_root_offset =
401 offsetof(struct thin_disk_superblock, metadata_space_map_root);
403 r = dm_tm_open_with_sm(bm, THIN_SUPERBLOCK_LOCATION,
404 &sb_validator, space_map_root_offset,
405 SPACE_MAP_ROOT_SIZE, &tm, &sm, &sblock);
407 DMERR("tm_open_with_sm failed");
411 disk_super = dm_block_data(sblock);
412 data_sm = dm_sm_disk_open(tm, disk_super->data_space_map_root,
413 sizeof(disk_super->data_space_map_root));
414 if (IS_ERR(data_sm)) {
415 DMERR("sm_disk_open failed");
416 r = PTR_ERR(data_sm);
422 r = dm_tm_unlock(tm, sblock);
424 DMERR("couldn't unlock superblock");
429 pmd->metadata_sm = sm;
430 pmd->data_sm = data_sm;
432 pmd->nb_tm = dm_tm_create_non_blocking_clone(tm);
434 DMERR("could not create clone tm");
440 pmd->info.levels = 2;
441 pmd->info.value_type.context = pmd->data_sm;
442 pmd->info.value_type.size = sizeof(__le64);
443 pmd->info.value_type.inc = data_block_inc;
444 pmd->info.value_type.dec = data_block_dec;
445 pmd->info.value_type.equal = data_block_equal;
447 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
448 pmd->nb_info.tm = pmd->nb_tm;
450 pmd->tl_info.tm = tm;
451 pmd->tl_info.levels = 1;
452 pmd->tl_info.value_type.context = &pmd->info;
453 pmd->tl_info.value_type.size = sizeof(__le64);
454 pmd->tl_info.value_type.inc = subtree_inc;
455 pmd->tl_info.value_type.dec = subtree_dec;
456 pmd->tl_info.value_type.equal = subtree_equal;
458 pmd->bl_info.tm = tm;
459 pmd->bl_info.levels = 1;
460 pmd->bl_info.value_type.context = pmd->data_sm;
461 pmd->bl_info.value_type.size = sizeof(__le64);
462 pmd->bl_info.value_type.inc = data_block_inc;
463 pmd->bl_info.value_type.dec = data_block_dec;
464 pmd->bl_info.value_type.equal = data_block_equal;
466 pmd->details_info.tm = tm;
467 pmd->details_info.levels = 1;
468 pmd->details_info.value_type.context = NULL;
469 pmd->details_info.value_type.size = sizeof(struct disk_device_details);
470 pmd->details_info.value_type.inc = NULL;
471 pmd->details_info.value_type.dec = NULL;
472 pmd->details_info.value_type.equal = NULL;
476 init_rwsem(&pmd->root_lock);
478 pmd->need_commit = 0;
479 pmd->details_root = 0;
482 INIT_LIST_HEAD(&pmd->thin_devices);
487 dm_sm_destroy(data_sm);
495 static int __begin_transaction(struct dm_pool_metadata *pmd)
499 struct thin_disk_superblock *disk_super;
500 struct dm_block *sblock;
503 * __maybe_commit_transaction() resets these
505 WARN_ON(pmd->need_commit);
508 * We re-read the superblock every time. Shouldn't need to do this
511 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
512 &sb_validator, &sblock);
516 disk_super = dm_block_data(sblock);
517 pmd->time = le32_to_cpu(disk_super->time);
518 pmd->root = le64_to_cpu(disk_super->data_mapping_root);
519 pmd->details_root = le64_to_cpu(disk_super->device_details_root);
520 pmd->trans_id = le64_to_cpu(disk_super->trans_id);
521 pmd->flags = le32_to_cpu(disk_super->flags);
522 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
524 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
526 DMERR("could not access metadata due to "
527 "unsupported optional features (%lx).",
528 (unsigned long)features);
534 * Check for read-only metadata to skip the following RDWR checks.
536 if (get_disk_ro(pmd->bdev->bd_disk))
539 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
541 DMERR("could not access metadata RDWR due to "
542 "unsupported optional features (%lx).",
543 (unsigned long)features);
548 dm_bm_unlock(sblock);
552 static int __write_changed_details(struct dm_pool_metadata *pmd)
555 struct dm_thin_device *td, *tmp;
556 struct disk_device_details details;
559 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
565 details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
566 details.transaction_id = cpu_to_le64(td->transaction_id);
567 details.creation_time = cpu_to_le32(td->creation_time);
568 details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
569 __dm_bless_for_disk(&details);
571 r = dm_btree_insert(&pmd->details_info, pmd->details_root,
572 &key, &details, &pmd->details_root);
583 pmd->need_commit = 1;
589 static int __commit_transaction(struct dm_pool_metadata *pmd)
592 * FIXME: Associated pool should be made read-only on failure.
595 size_t metadata_len, data_len;
596 struct thin_disk_superblock *disk_super;
597 struct dm_block *sblock;
600 * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
602 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
604 r = __write_changed_details(pmd);
608 if (!pmd->need_commit)
611 r = dm_sm_commit(pmd->data_sm);
615 r = dm_tm_pre_commit(pmd->tm);
619 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
623 r = dm_sm_root_size(pmd->metadata_sm, &data_len);
627 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
628 &sb_validator, &sblock);
632 disk_super = dm_block_data(sblock);
633 disk_super->time = cpu_to_le32(pmd->time);
634 disk_super->data_mapping_root = cpu_to_le64(pmd->root);
635 disk_super->device_details_root = cpu_to_le64(pmd->details_root);
636 disk_super->trans_id = cpu_to_le64(pmd->trans_id);
637 disk_super->flags = cpu_to_le32(pmd->flags);
639 r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
644 r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
649 r = dm_tm_commit(pmd->tm, sblock);
651 pmd->need_commit = 0;
657 dm_bm_unlock(sblock);
661 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
662 sector_t data_block_size)
665 struct thin_disk_superblock *disk_super;
666 struct dm_pool_metadata *pmd;
667 sector_t bdev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
668 struct dm_block_manager *bm;
670 struct dm_block *sblock;
672 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
674 DMERR("could not allocate metadata struct");
675 return ERR_PTR(-ENOMEM);
678 bm = dm_block_manager_create(bdev, THIN_METADATA_BLOCK_SIZE,
679 THIN_METADATA_CACHE_SIZE,
680 THIN_MAX_CONCURRENT_LOCKS);
682 DMERR("could not create block manager");
684 return ERR_PTR(-ENOMEM);
687 r = superblock_all_zeroes(bm, &create);
689 dm_block_manager_destroy(bm);
695 r = init_pmd(pmd, bm, 0, create);
697 dm_block_manager_destroy(bm);
704 r = __begin_transaction(pmd);
713 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
714 &sb_validator, &sblock);
718 disk_super = dm_block_data(sblock);
719 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
720 disk_super->version = cpu_to_le32(THIN_VERSION);
721 disk_super->time = 0;
722 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
723 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
724 disk_super->data_block_size = cpu_to_le32(data_block_size);
726 r = dm_bm_unlock(sblock);
730 r = dm_btree_empty(&pmd->info, &pmd->root);
734 r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
736 DMERR("couldn't create devices root");
741 pmd->need_commit = 1;
742 r = dm_pool_commit_metadata(pmd);
744 DMERR("%s: dm_pool_commit_metadata() failed, error = %d",
752 if (dm_pool_metadata_close(pmd) < 0)
753 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
757 int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
760 unsigned open_devices = 0;
761 struct dm_thin_device *td, *tmp;
763 down_read(&pmd->root_lock);
764 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
772 up_read(&pmd->root_lock);
775 DMERR("attempt to close pmd when %u device(s) are still open",
780 r = __commit_transaction(pmd);
782 DMWARN("%s: __commit_transaction() failed, error = %d",
785 dm_tm_destroy(pmd->tm);
786 dm_tm_destroy(pmd->nb_tm);
787 dm_block_manager_destroy(pmd->bm);
788 dm_sm_destroy(pmd->metadata_sm);
789 dm_sm_destroy(pmd->data_sm);
796 * __open_device: Returns @td corresponding to device with id @dev,
797 * creating it if @create is set and incrementing @td->open_count.
798 * On failure, @td is undefined.
800 static int __open_device(struct dm_pool_metadata *pmd,
801 dm_thin_id dev, int create,
802 struct dm_thin_device **td)
805 struct dm_thin_device *td2;
807 struct disk_device_details details_le;
810 * If the device is already open, return it.
812 list_for_each_entry(td2, &pmd->thin_devices, list)
813 if (td2->id == dev) {
815 * May not create an already-open device.
826 * Check the device exists.
828 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
831 if (r != -ENODATA || !create)
838 details_le.mapped_blocks = 0;
839 details_le.transaction_id = cpu_to_le64(pmd->trans_id);
840 details_le.creation_time = cpu_to_le32(pmd->time);
841 details_le.snapshotted_time = cpu_to_le32(pmd->time);
844 *td = kmalloc(sizeof(**td), GFP_NOIO);
850 (*td)->open_count = 1;
851 (*td)->changed = changed;
852 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
853 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
854 (*td)->creation_time = le32_to_cpu(details_le.creation_time);
855 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
857 list_add(&(*td)->list, &pmd->thin_devices);
862 static void __close_device(struct dm_thin_device *td)
867 static int __create_thin(struct dm_pool_metadata *pmd,
873 struct disk_device_details details_le;
874 struct dm_thin_device *td;
877 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
883 * Create an empty btree for the mappings.
885 r = dm_btree_empty(&pmd->bl_info, &dev_root);
890 * Insert it into the main mapping tree.
892 value = cpu_to_le64(dev_root);
893 __dm_bless_for_disk(&value);
894 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
896 dm_btree_del(&pmd->bl_info, dev_root);
900 r = __open_device(pmd, dev, 1, &td);
902 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
903 dm_btree_del(&pmd->bl_info, dev_root);
911 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
915 down_write(&pmd->root_lock);
916 r = __create_thin(pmd, dev);
917 up_write(&pmd->root_lock);
922 static int __set_snapshot_details(struct dm_pool_metadata *pmd,
923 struct dm_thin_device *snap,
924 dm_thin_id origin, uint32_t time)
927 struct dm_thin_device *td;
929 r = __open_device(pmd, origin, 0, &td);
934 td->snapshotted_time = time;
936 snap->mapped_blocks = td->mapped_blocks;
937 snap->snapshotted_time = time;
943 static int __create_snap(struct dm_pool_metadata *pmd,
944 dm_thin_id dev, dm_thin_id origin)
947 dm_block_t origin_root;
948 uint64_t key = origin, dev_key = dev;
949 struct dm_thin_device *td;
950 struct disk_device_details details_le;
953 /* check this device is unused */
954 r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
955 &dev_key, &details_le);
959 /* find the mapping tree for the origin */
960 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
963 origin_root = le64_to_cpu(value);
965 /* clone the origin, an inc will do */
966 dm_tm_inc(pmd->tm, origin_root);
968 /* insert into the main mapping tree */
969 value = cpu_to_le64(origin_root);
970 __dm_bless_for_disk(&value);
972 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
974 dm_tm_dec(pmd->tm, origin_root);
980 r = __open_device(pmd, dev, 1, &td);
984 r = __set_snapshot_details(pmd, td, origin, pmd->time);
993 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
994 dm_btree_remove(&pmd->details_info, pmd->details_root,
995 &key, &pmd->details_root);
999 int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1005 down_write(&pmd->root_lock);
1006 r = __create_snap(pmd, dev, origin);
1007 up_write(&pmd->root_lock);
1012 static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1016 struct dm_thin_device *td;
1018 /* TODO: failure should mark the transaction invalid */
1019 r = __open_device(pmd, dev, 0, &td);
1023 if (td->open_count > 1) {
1028 list_del(&td->list);
1030 r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1031 &key, &pmd->details_root);
1035 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1039 pmd->need_commit = 1;
1044 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1049 down_write(&pmd->root_lock);
1050 r = __delete_device(pmd, dev);
1051 up_write(&pmd->root_lock);
1056 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1057 uint64_t current_id,
1060 down_write(&pmd->root_lock);
1061 if (pmd->trans_id != current_id) {
1062 up_write(&pmd->root_lock);
1063 DMERR("mismatched transaction id");
1067 pmd->trans_id = new_id;
1068 pmd->need_commit = 1;
1069 up_write(&pmd->root_lock);
1074 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1077 down_read(&pmd->root_lock);
1078 *result = pmd->trans_id;
1079 up_read(&pmd->root_lock);
1084 static int __get_held_metadata_root(struct dm_pool_metadata *pmd,
1088 struct thin_disk_superblock *disk_super;
1089 struct dm_block *sblock;
1091 r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1092 &sb_validator, &sblock);
1096 disk_super = dm_block_data(sblock);
1097 *result = le64_to_cpu(disk_super->held_root);
1099 return dm_bm_unlock(sblock);
1102 int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd,
1107 down_read(&pmd->root_lock);
1108 r = __get_held_metadata_root(pmd, result);
1109 up_read(&pmd->root_lock);
1114 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1115 struct dm_thin_device **td)
1119 down_write(&pmd->root_lock);
1120 r = __open_device(pmd, dev, 0, td);
1121 up_write(&pmd->root_lock);
1126 int dm_pool_close_thin_device(struct dm_thin_device *td)
1128 down_write(&td->pmd->root_lock);
1130 up_write(&td->pmd->root_lock);
1135 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1140 static int __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1142 return td->snapshotted_time > time;
1145 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1146 int can_block, struct dm_thin_lookup_result *result)
1149 uint64_t block_time = 0;
1151 struct dm_pool_metadata *pmd = td->pmd;
1152 dm_block_t keys[2] = { td->id, block };
1155 down_read(&pmd->root_lock);
1156 r = dm_btree_lookup(&pmd->info, pmd->root, keys, &value);
1158 block_time = le64_to_cpu(value);
1159 up_read(&pmd->root_lock);
1161 } else if (down_read_trylock(&pmd->root_lock)) {
1162 r = dm_btree_lookup(&pmd->nb_info, pmd->root, keys, &value);
1164 block_time = le64_to_cpu(value);
1165 up_read(&pmd->root_lock);
1168 return -EWOULDBLOCK;
1171 dm_block_t exception_block;
1172 uint32_t exception_time;
1173 unpack_block_time(block_time, &exception_block,
1175 result->block = exception_block;
1176 result->shared = __snapshotted_since(td, exception_time);
1182 static int __insert(struct dm_thin_device *td, dm_block_t block,
1183 dm_block_t data_block)
1187 struct dm_pool_metadata *pmd = td->pmd;
1188 dm_block_t keys[2] = { td->id, block };
1190 pmd->need_commit = 1;
1191 value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1192 __dm_bless_for_disk(&value);
1194 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1195 &pmd->root, &inserted);
1200 td->mapped_blocks++;
1207 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1208 dm_block_t data_block)
1212 down_write(&td->pmd->root_lock);
1213 r = __insert(td, block, data_block);
1214 up_write(&td->pmd->root_lock);
1219 static int __remove(struct dm_thin_device *td, dm_block_t block)
1222 struct dm_pool_metadata *pmd = td->pmd;
1223 dm_block_t keys[2] = { td->id, block };
1225 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1229 td->mapped_blocks--;
1231 pmd->need_commit = 1;
1236 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1240 down_write(&td->pmd->root_lock);
1241 r = __remove(td, block);
1242 up_write(&td->pmd->root_lock);
1247 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1251 down_write(&pmd->root_lock);
1253 r = dm_sm_new_block(pmd->data_sm, result);
1254 pmd->need_commit = 1;
1256 up_write(&pmd->root_lock);
1261 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1265 down_write(&pmd->root_lock);
1267 r = __commit_transaction(pmd);
1272 * Open the next transaction.
1274 r = __begin_transaction(pmd);
1276 up_write(&pmd->root_lock);
1280 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1284 down_read(&pmd->root_lock);
1285 r = dm_sm_get_nr_free(pmd->data_sm, result);
1286 up_read(&pmd->root_lock);
1291 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1296 down_read(&pmd->root_lock);
1297 r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1298 up_read(&pmd->root_lock);
1303 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1308 down_read(&pmd->root_lock);
1309 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1310 up_read(&pmd->root_lock);
1315 int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result)
1317 down_read(&pmd->root_lock);
1318 *result = pmd->data_block_size;
1319 up_read(&pmd->root_lock);
1324 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1328 down_read(&pmd->root_lock);
1329 r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1330 up_read(&pmd->root_lock);
1335 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1337 struct dm_pool_metadata *pmd = td->pmd;
1339 down_read(&pmd->root_lock);
1340 *result = td->mapped_blocks;
1341 up_read(&pmd->root_lock);
1346 static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1350 dm_block_t thin_root;
1351 struct dm_pool_metadata *pmd = td->pmd;
1353 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1357 thin_root = le64_to_cpu(value_le);
1359 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1362 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1366 struct dm_pool_metadata *pmd = td->pmd;
1368 down_read(&pmd->root_lock);
1369 r = __highest_block(td, result);
1370 up_read(&pmd->root_lock);
1375 static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1378 dm_block_t old_count;
1380 r = dm_sm_get_nr_blocks(pmd->data_sm, &old_count);
1384 if (new_count == old_count)
1387 if (new_count < old_count) {
1388 DMERR("cannot reduce size of data device");
1392 r = dm_sm_extend(pmd->data_sm, new_count - old_count);
1394 pmd->need_commit = 1;
1399 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1403 down_write(&pmd->root_lock);
1404 r = __resize_data_dev(pmd, new_count);
1405 up_write(&pmd->root_lock);