diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-thin-metadata.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/dm-thin-metadata.c | 1409 |
1 files changed, 0 insertions, 1409 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-thin-metadata.c b/ANDROID_3.4.5/drivers/md/dm-thin-metadata.c deleted file mode 100644 index 737d3886..00000000 --- a/ANDROID_3.4.5/drivers/md/dm-thin-metadata.c +++ /dev/null @@ -1,1409 +0,0 @@ -/* - * Copyright (C) 2011 Red Hat, Inc. - * - * This file is released under the GPL. - */ - -#include "dm-thin-metadata.h" -#include "persistent-data/dm-btree.h" -#include "persistent-data/dm-space-map.h" -#include "persistent-data/dm-space-map-disk.h" -#include "persistent-data/dm-transaction-manager.h" - -#include <linux/list.h> -#include <linux/device-mapper.h> -#include <linux/workqueue.h> - -/*-------------------------------------------------------------------------- - * As far as the metadata goes, there is: - * - * - A superblock in block zero, taking up fewer than 512 bytes for - * atomic writes. - * - * - A space map managing the metadata blocks. - * - * - A space map managing the data blocks. - * - * - A btree mapping our internal thin dev ids onto struct disk_device_details. - * - * - A hierarchical btree, with 2 levels which effectively maps (thin - * dev id, virtual block) -> block_time. Block time is a 64-bit - * field holding the time in the low 24 bits, and block in the top 48 - * bits. - * - * BTrees consist solely of btree_nodes, that fill a block. Some are - * internal nodes, as such their values are a __le64 pointing to other - * nodes. Leaf nodes can store data of any reasonable size (ie. much - * smaller than the block size). The nodes consist of the header, - * followed by an array of keys, followed by an array of values. We have - * to binary search on the keys so they're all held together to help the - * cpu cache. - * - * Space maps have 2 btrees: - * - * - One maps a uint64_t onto a struct index_entry. Which points to a - * bitmap block, and has some details about how many free entries there - * are etc. - * - * - The bitmap blocks have a header (for the checksum). Then the rest - * of the block is pairs of bits. With the meaning being: - * - * 0 - ref count is 0 - * 1 - ref count is 1 - * 2 - ref count is 2 - * 3 - ref count is higher than 2 - * - * - If the count is higher than 2 then the ref count is entered in a - * second btree that directly maps the block_address to a uint32_t ref - * count. - * - * The space map metadata variant doesn't have a bitmaps btree. Instead - * it has one single blocks worth of index_entries. This avoids - * recursive issues with the bitmap btree needing to allocate space in - * order to insert. With a small data block size such as 64k the - * metadata support data devices that are hundreds of terrabytes. - * - * The space maps allocate space linearly from front to back. Space that - * is freed in a transaction is never recycled within that transaction. - * To try and avoid fragmenting _free_ space the allocator always goes - * back and fills in gaps. - * - * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks - * from the block manager. - *--------------------------------------------------------------------------*/ - -#define DM_MSG_PREFIX "thin metadata" - -#define THIN_SUPERBLOCK_MAGIC 27022010 -#define THIN_SUPERBLOCK_LOCATION 0 -#define THIN_VERSION 1 -#define THIN_METADATA_CACHE_SIZE 64 -#define SECTOR_TO_BLOCK_SHIFT 3 - -/* This should be plenty */ -#define SPACE_MAP_ROOT_SIZE 128 - -/* - * Little endian on-disk superblock and device details. - */ -struct thin_disk_superblock { - __le32 csum; /* Checksum of superblock except for this field. */ - __le32 flags; - __le64 blocknr; /* This block number, dm_block_t. */ - - __u8 uuid[16]; - __le64 magic; - __le32 version; - __le32 time; - - __le64 trans_id; - - /* - * Root held by userspace transactions. - */ - __le64 held_root; - - __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; - __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; - - /* - * 2-level btree mapping (dev_id, (dev block, time)) -> data block - */ - __le64 data_mapping_root; - - /* - * Device detail root mapping dev_id -> device_details - */ - __le64 device_details_root; - - __le32 data_block_size; /* In 512-byte sectors. */ - - __le32 metadata_block_size; /* In 512-byte sectors. */ - __le64 metadata_nr_blocks; - - __le32 compat_flags; - __le32 compat_ro_flags; - __le32 incompat_flags; -} __packed; - -struct disk_device_details { - __le64 mapped_blocks; - __le64 transaction_id; /* When created. */ - __le32 creation_time; - __le32 snapshotted_time; -} __packed; - -struct dm_pool_metadata { - struct hlist_node hash; - - struct block_device *bdev; - struct dm_block_manager *bm; - struct dm_space_map *metadata_sm; - struct dm_space_map *data_sm; - struct dm_transaction_manager *tm; - struct dm_transaction_manager *nb_tm; - - /* - * Two-level btree. - * First level holds thin_dev_t. - * Second level holds mappings. - */ - struct dm_btree_info info; - - /* - * Non-blocking version of the above. - */ - struct dm_btree_info nb_info; - - /* - * Just the top level for deleting whole devices. - */ - struct dm_btree_info tl_info; - - /* - * Just the bottom level for creating new devices. - */ - struct dm_btree_info bl_info; - - /* - * Describes the device details btree. - */ - struct dm_btree_info details_info; - - struct rw_semaphore root_lock; - uint32_t time; - int need_commit; - dm_block_t root; - dm_block_t details_root; - struct list_head thin_devices; - uint64_t trans_id; - unsigned long flags; - sector_t data_block_size; -}; - -struct dm_thin_device { - struct list_head list; - struct dm_pool_metadata *pmd; - dm_thin_id id; - - int open_count; - int changed; - uint64_t mapped_blocks; - uint64_t transaction_id; - uint32_t creation_time; - uint32_t snapshotted_time; -}; - -/*---------------------------------------------------------------- - * superblock validator - *--------------------------------------------------------------*/ - -#define SUPERBLOCK_CSUM_XOR 160774 - -static void sb_prepare_for_write(struct dm_block_validator *v, - struct dm_block *b, - size_t block_size) -{ - struct thin_disk_superblock *disk_super = dm_block_data(b); - - disk_super->blocknr = cpu_to_le64(dm_block_location(b)); - disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, - block_size - sizeof(__le32), - SUPERBLOCK_CSUM_XOR)); -} - -static int sb_check(struct dm_block_validator *v, - struct dm_block *b, - size_t block_size) -{ - struct thin_disk_superblock *disk_super = dm_block_data(b); - __le32 csum_le; - - if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { - DMERR("sb_check failed: blocknr %llu: " - "wanted %llu", le64_to_cpu(disk_super->blocknr), - (unsigned long long)dm_block_location(b)); - return -ENOTBLK; - } - - if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) { - DMERR("sb_check failed: magic %llu: " - "wanted %llu", le64_to_cpu(disk_super->magic), - (unsigned long long)THIN_SUPERBLOCK_MAGIC); - return -EILSEQ; - } - - csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, - block_size - sizeof(__le32), - SUPERBLOCK_CSUM_XOR)); - if (csum_le != disk_super->csum) { - DMERR("sb_check failed: csum %u: wanted %u", - le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); - return -EILSEQ; - } - - return 0; -} - -static struct dm_block_validator sb_validator = { - .name = "superblock", - .prepare_for_write = sb_prepare_for_write, - .check = sb_check -}; - -/*---------------------------------------------------------------- - * Methods for the btree value types - *--------------------------------------------------------------*/ - -static uint64_t pack_block_time(dm_block_t b, uint32_t t) -{ - return (b << 24) | t; -} - -static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) -{ - *b = v >> 24; - *t = v & ((1 << 24) - 1); -} - -static void data_block_inc(void *context, void *value_le) -{ - struct dm_space_map *sm = context; - __le64 v_le; - uint64_t b; - uint32_t t; - - memcpy(&v_le, value_le, sizeof(v_le)); - unpack_block_time(le64_to_cpu(v_le), &b, &t); - dm_sm_inc_block(sm, b); -} - -static void data_block_dec(void *context, void *value_le) -{ - struct dm_space_map *sm = context; - __le64 v_le; - uint64_t b; - uint32_t t; - - memcpy(&v_le, value_le, sizeof(v_le)); - unpack_block_time(le64_to_cpu(v_le), &b, &t); - dm_sm_dec_block(sm, b); -} - -static int data_block_equal(void *context, void *value1_le, void *value2_le) -{ - __le64 v1_le, v2_le; - uint64_t b1, b2; - uint32_t t; - - memcpy(&v1_le, value1_le, sizeof(v1_le)); - memcpy(&v2_le, value2_le, sizeof(v2_le)); - unpack_block_time(le64_to_cpu(v1_le), &b1, &t); - unpack_block_time(le64_to_cpu(v2_le), &b2, &t); - - return b1 == b2; -} - -static void subtree_inc(void *context, void *value) -{ - struct dm_btree_info *info = context; - __le64 root_le; - uint64_t root; - - memcpy(&root_le, value, sizeof(root_le)); - root = le64_to_cpu(root_le); - dm_tm_inc(info->tm, root); -} - -static void subtree_dec(void *context, void *value) -{ - struct dm_btree_info *info = context; - __le64 root_le; - uint64_t root; - - memcpy(&root_le, value, sizeof(root_le)); - root = le64_to_cpu(root_le); - if (dm_btree_del(info, root)) - DMERR("btree delete failed\n"); -} - -static int subtree_equal(void *context, void *value1_le, void *value2_le) -{ - __le64 v1_le, v2_le; - memcpy(&v1_le, value1_le, sizeof(v1_le)); - memcpy(&v2_le, value2_le, sizeof(v2_le)); - - return v1_le == v2_le; -} - -/*----------------------------------------------------------------*/ - -static int superblock_all_zeroes(struct dm_block_manager *bm, int *result) -{ - int r; - unsigned i; - struct dm_block *b; - __le64 *data_le, zero = cpu_to_le64(0); - unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64); - - /* - * We can't use a validator here - it may be all zeroes. - */ - r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b); - if (r) - return r; - - data_le = dm_block_data(b); - *result = 1; - for (i = 0; i < block_size; i++) { - if (data_le[i] != zero) { - *result = 0; - break; - } - } - - return dm_bm_unlock(b); -} - -static int init_pmd(struct dm_pool_metadata *pmd, - struct dm_block_manager *bm, - dm_block_t nr_blocks, int create) -{ - int r; - struct dm_space_map *sm, *data_sm; - struct dm_transaction_manager *tm; - struct dm_block *sblock; - - if (create) { - r = dm_tm_create_with_sm(bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &tm, &sm, &sblock); - if (r < 0) { - DMERR("tm_create_with_sm failed"); - return r; - } - - data_sm = dm_sm_disk_create(tm, nr_blocks); - if (IS_ERR(data_sm)) { - DMERR("sm_disk_create failed"); - dm_tm_unlock(tm, sblock); - r = PTR_ERR(data_sm); - goto bad; - } - } else { - struct thin_disk_superblock *disk_super = NULL; - size_t space_map_root_offset = - offsetof(struct thin_disk_superblock, metadata_space_map_root); - - r = dm_tm_open_with_sm(bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, space_map_root_offset, - SPACE_MAP_ROOT_SIZE, &tm, &sm, &sblock); - if (r < 0) { - DMERR("tm_open_with_sm failed"); - return r; - } - - disk_super = dm_block_data(sblock); - data_sm = dm_sm_disk_open(tm, disk_super->data_space_map_root, - sizeof(disk_super->data_space_map_root)); - if (IS_ERR(data_sm)) { - DMERR("sm_disk_open failed"); - r = PTR_ERR(data_sm); - goto bad; - } - } - - - r = dm_tm_unlock(tm, sblock); - if (r < 0) { - DMERR("couldn't unlock superblock"); - goto bad_data_sm; - } - - pmd->bm = bm; - pmd->metadata_sm = sm; - pmd->data_sm = data_sm; - pmd->tm = tm; - pmd->nb_tm = dm_tm_create_non_blocking_clone(tm); - if (!pmd->nb_tm) { - DMERR("could not create clone tm"); - r = -ENOMEM; - goto bad_data_sm; - } - - pmd->info.tm = tm; - pmd->info.levels = 2; - pmd->info.value_type.context = pmd->data_sm; - pmd->info.value_type.size = sizeof(__le64); - pmd->info.value_type.inc = data_block_inc; - pmd->info.value_type.dec = data_block_dec; - pmd->info.value_type.equal = data_block_equal; - - memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info)); - pmd->nb_info.tm = pmd->nb_tm; - - pmd->tl_info.tm = tm; - pmd->tl_info.levels = 1; - pmd->tl_info.value_type.context = &pmd->info; - pmd->tl_info.value_type.size = sizeof(__le64); - pmd->tl_info.value_type.inc = subtree_inc; - pmd->tl_info.value_type.dec = subtree_dec; - pmd->tl_info.value_type.equal = subtree_equal; - - pmd->bl_info.tm = tm; - pmd->bl_info.levels = 1; - pmd->bl_info.value_type.context = pmd->data_sm; - pmd->bl_info.value_type.size = sizeof(__le64); - pmd->bl_info.value_type.inc = data_block_inc; - pmd->bl_info.value_type.dec = data_block_dec; - pmd->bl_info.value_type.equal = data_block_equal; - - pmd->details_info.tm = tm; - pmd->details_info.levels = 1; - pmd->details_info.value_type.context = NULL; - pmd->details_info.value_type.size = sizeof(struct disk_device_details); - pmd->details_info.value_type.inc = NULL; - pmd->details_info.value_type.dec = NULL; - pmd->details_info.value_type.equal = NULL; - - pmd->root = 0; - - init_rwsem(&pmd->root_lock); - pmd->time = 0; - pmd->need_commit = 0; - pmd->details_root = 0; - pmd->trans_id = 0; - pmd->flags = 0; - INIT_LIST_HEAD(&pmd->thin_devices); - - return 0; - -bad_data_sm: - dm_sm_destroy(data_sm); -bad: - dm_tm_destroy(tm); - dm_sm_destroy(sm); - - return r; -} - -static int __begin_transaction(struct dm_pool_metadata *pmd) -{ - int r; - u32 features; - struct thin_disk_superblock *disk_super; - struct dm_block *sblock; - - /* - * __maybe_commit_transaction() resets these - */ - WARN_ON(pmd->need_commit); - - /* - * We re-read the superblock every time. Shouldn't need to do this - * really. - */ - r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &sblock); - if (r) - return r; - - disk_super = dm_block_data(sblock); - pmd->time = le32_to_cpu(disk_super->time); - pmd->root = le64_to_cpu(disk_super->data_mapping_root); - pmd->details_root = le64_to_cpu(disk_super->device_details_root); - pmd->trans_id = le64_to_cpu(disk_super->trans_id); - pmd->flags = le32_to_cpu(disk_super->flags); - pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); - - features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP; - if (features) { - DMERR("could not access metadata due to " - "unsupported optional features (%lx).", - (unsigned long)features); - r = -EINVAL; - goto out; - } - - /* - * Check for read-only metadata to skip the following RDWR checks. - */ - if (get_disk_ro(pmd->bdev->bd_disk)) - goto out; - - features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP; - if (features) { - DMERR("could not access metadata RDWR due to " - "unsupported optional features (%lx).", - (unsigned long)features); - r = -EINVAL; - } - -out: - dm_bm_unlock(sblock); - return r; -} - -static int __write_changed_details(struct dm_pool_metadata *pmd) -{ - int r; - struct dm_thin_device *td, *tmp; - struct disk_device_details details; - uint64_t key; - - list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { - if (!td->changed) - continue; - - key = td->id; - - details.mapped_blocks = cpu_to_le64(td->mapped_blocks); - details.transaction_id = cpu_to_le64(td->transaction_id); - details.creation_time = cpu_to_le32(td->creation_time); - details.snapshotted_time = cpu_to_le32(td->snapshotted_time); - __dm_bless_for_disk(&details); - - r = dm_btree_insert(&pmd->details_info, pmd->details_root, - &key, &details, &pmd->details_root); - if (r) - return r; - - if (td->open_count) - td->changed = 0; - else { - list_del(&td->list); - kfree(td); - } - - pmd->need_commit = 1; - } - - return 0; -} - -static int __commit_transaction(struct dm_pool_metadata *pmd) -{ - /* - * FIXME: Associated pool should be made read-only on failure. - */ - int r; - size_t metadata_len, data_len; - struct thin_disk_superblock *disk_super; - struct dm_block *sblock; - - /* - * We need to know if the thin_disk_superblock exceeds a 512-byte sector. - */ - BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); - - r = __write_changed_details(pmd); - if (r < 0) - goto out; - - if (!pmd->need_commit) - goto out; - - r = dm_sm_commit(pmd->data_sm); - if (r < 0) - goto out; - - r = dm_tm_pre_commit(pmd->tm); - if (r < 0) - goto out; - - r = dm_sm_root_size(pmd->metadata_sm, &metadata_len); - if (r < 0) - goto out; - - r = dm_sm_root_size(pmd->data_sm, &data_len); - if (r < 0) - goto out; - - r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &sblock); - if (r) - goto out; - - disk_super = dm_block_data(sblock); - disk_super->time = cpu_to_le32(pmd->time); - disk_super->data_mapping_root = cpu_to_le64(pmd->root); - disk_super->device_details_root = cpu_to_le64(pmd->details_root); - disk_super->trans_id = cpu_to_le64(pmd->trans_id); - disk_super->flags = cpu_to_le32(pmd->flags); - - r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root, - metadata_len); - if (r < 0) - goto out_locked; - - r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root, - data_len); - if (r < 0) - goto out_locked; - - r = dm_tm_commit(pmd->tm, sblock); - if (!r) - pmd->need_commit = 0; - -out: - return r; - -out_locked: - dm_bm_unlock(sblock); - return r; -} - -struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, - sector_t data_block_size) -{ - int r; - struct thin_disk_superblock *disk_super; - struct dm_pool_metadata *pmd; - sector_t bdev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT; - struct dm_block_manager *bm; - int create; - struct dm_block *sblock; - - pmd = kmalloc(sizeof(*pmd), GFP_KERNEL); - if (!pmd) { - DMERR("could not allocate metadata struct"); - return ERR_PTR(-ENOMEM); - } - - /* - * Max hex locks: - * 3 for btree insert + - * 2 for btree lookup used within space map - */ - bm = dm_block_manager_create(bdev, THIN_METADATA_BLOCK_SIZE, - THIN_METADATA_CACHE_SIZE, 5); - if (!bm) { - DMERR("could not create block manager"); - kfree(pmd); - return ERR_PTR(-ENOMEM); - } - - r = superblock_all_zeroes(bm, &create); - if (r) { - dm_block_manager_destroy(bm); - kfree(pmd); - return ERR_PTR(r); - } - - - r = init_pmd(pmd, bm, 0, create); - if (r) { - dm_block_manager_destroy(bm); - kfree(pmd); - return ERR_PTR(r); - } - pmd->bdev = bdev; - - if (!create) { - r = __begin_transaction(pmd); - if (r < 0) - goto bad; - return pmd; - } - - /* - * Create. - */ - r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &sblock); - if (r) - goto bad; - - if (bdev_size > THIN_METADATA_MAX_SECTORS) - bdev_size = THIN_METADATA_MAX_SECTORS; - - disk_super = dm_block_data(sblock); - disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); - disk_super->version = cpu_to_le32(THIN_VERSION); - disk_super->time = 0; - disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); - disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT); - disk_super->data_block_size = cpu_to_le32(data_block_size); - - r = dm_bm_unlock(sblock); - if (r < 0) - goto bad; - - r = dm_btree_empty(&pmd->info, &pmd->root); - if (r < 0) - goto bad; - - r = dm_btree_empty(&pmd->details_info, &pmd->details_root); - if (r < 0) { - DMERR("couldn't create devices root"); - goto bad; - } - - pmd->flags = 0; - pmd->need_commit = 1; - r = dm_pool_commit_metadata(pmd); - if (r < 0) { - DMERR("%s: dm_pool_commit_metadata() failed, error = %d", - __func__, r); - goto bad; - } - - return pmd; - -bad: - if (dm_pool_metadata_close(pmd) < 0) - DMWARN("%s: dm_pool_metadata_close() failed.", __func__); - return ERR_PTR(r); -} - -int dm_pool_metadata_close(struct dm_pool_metadata *pmd) -{ - int r; - unsigned open_devices = 0; - struct dm_thin_device *td, *tmp; - - down_read(&pmd->root_lock); - list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { - if (td->open_count) - open_devices++; - else { - list_del(&td->list); - kfree(td); - } - } - up_read(&pmd->root_lock); - - if (open_devices) { - DMERR("attempt to close pmd when %u device(s) are still open", - open_devices); - return -EBUSY; - } - - r = __commit_transaction(pmd); - if (r < 0) - DMWARN("%s: __commit_transaction() failed, error = %d", - __func__, r); - - dm_tm_destroy(pmd->tm); - dm_tm_destroy(pmd->nb_tm); - dm_block_manager_destroy(pmd->bm); - dm_sm_destroy(pmd->metadata_sm); - dm_sm_destroy(pmd->data_sm); - kfree(pmd); - - return 0; -} - -/* - * __open_device: Returns @td corresponding to device with id @dev, - * creating it if @create is set and incrementing @td->open_count. - * On failure, @td is undefined. - */ -static int __open_device(struct dm_pool_metadata *pmd, - dm_thin_id dev, int create, - struct dm_thin_device **td) -{ - int r, changed = 0; - struct dm_thin_device *td2; - uint64_t key = dev; - struct disk_device_details details_le; - - /* - * If the device is already open, return it. - */ - list_for_each_entry(td2, &pmd->thin_devices, list) - if (td2->id == dev) { - /* - * May not create an already-open device. - */ - if (create) - return -EEXIST; - - td2->open_count++; - *td = td2; - return 0; - } - - /* - * Check the device exists. - */ - r = dm_btree_lookup(&pmd->details_info, pmd->details_root, - &key, &details_le); - if (r) { - if (r != -ENODATA || !create) - return r; - - /* - * Create new device. - */ - changed = 1; - details_le.mapped_blocks = 0; - details_le.transaction_id = cpu_to_le64(pmd->trans_id); - details_le.creation_time = cpu_to_le32(pmd->time); - details_le.snapshotted_time = cpu_to_le32(pmd->time); - } - - *td = kmalloc(sizeof(**td), GFP_NOIO); - if (!*td) - return -ENOMEM; - - (*td)->pmd = pmd; - (*td)->id = dev; - (*td)->open_count = 1; - (*td)->changed = changed; - (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks); - (*td)->transaction_id = le64_to_cpu(details_le.transaction_id); - (*td)->creation_time = le32_to_cpu(details_le.creation_time); - (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time); - - list_add(&(*td)->list, &pmd->thin_devices); - - return 0; -} - -static void __close_device(struct dm_thin_device *td) -{ - --td->open_count; -} - -static int __create_thin(struct dm_pool_metadata *pmd, - dm_thin_id dev) -{ - int r; - dm_block_t dev_root; - uint64_t key = dev; - struct disk_device_details details_le; - struct dm_thin_device *td; - __le64 value; - - r = dm_btree_lookup(&pmd->details_info, pmd->details_root, - &key, &details_le); - if (!r) - return -EEXIST; - - /* - * Create an empty btree for the mappings. - */ - r = dm_btree_empty(&pmd->bl_info, &dev_root); - if (r) - return r; - - /* - * Insert it into the main mapping tree. - */ - value = cpu_to_le64(dev_root); - __dm_bless_for_disk(&value); - r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); - if (r) { - dm_btree_del(&pmd->bl_info, dev_root); - return r; - } - - r = __open_device(pmd, dev, 1, &td); - if (r) { - dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); - dm_btree_del(&pmd->bl_info, dev_root); - return r; - } - __close_device(td); - - return r; -} - -int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev) -{ - int r; - - down_write(&pmd->root_lock); - r = __create_thin(pmd, dev); - up_write(&pmd->root_lock); - - return r; -} - -static int __set_snapshot_details(struct dm_pool_metadata *pmd, - struct dm_thin_device *snap, - dm_thin_id origin, uint32_t time) -{ - int r; - struct dm_thin_device *td; - - r = __open_device(pmd, origin, 0, &td); - if (r) - return r; - - td->changed = 1; - td->snapshotted_time = time; - - snap->mapped_blocks = td->mapped_blocks; - snap->snapshotted_time = time; - __close_device(td); - - return 0; -} - -static int __create_snap(struct dm_pool_metadata *pmd, - dm_thin_id dev, dm_thin_id origin) -{ - int r; - dm_block_t origin_root; - uint64_t key = origin, dev_key = dev; - struct dm_thin_device *td; - struct disk_device_details details_le; - __le64 value; - - /* check this device is unused */ - r = dm_btree_lookup(&pmd->details_info, pmd->details_root, - &dev_key, &details_le); - if (!r) - return -EEXIST; - - /* find the mapping tree for the origin */ - r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value); - if (r) - return r; - origin_root = le64_to_cpu(value); - - /* clone the origin, an inc will do */ - dm_tm_inc(pmd->tm, origin_root); - - /* insert into the main mapping tree */ - value = cpu_to_le64(origin_root); - __dm_bless_for_disk(&value); - key = dev; - r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); - if (r) { - dm_tm_dec(pmd->tm, origin_root); - return r; - } - - pmd->time++; - - r = __open_device(pmd, dev, 1, &td); - if (r) - goto bad; - - r = __set_snapshot_details(pmd, td, origin, pmd->time); - __close_device(td); - - if (r) - goto bad; - - return 0; - -bad: - dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); - dm_btree_remove(&pmd->details_info, pmd->details_root, - &key, &pmd->details_root); - return r; -} - -int dm_pool_create_snap(struct dm_pool_metadata *pmd, - dm_thin_id dev, - dm_thin_id origin) -{ - int r; - - down_write(&pmd->root_lock); - r = __create_snap(pmd, dev, origin); - up_write(&pmd->root_lock); - - return r; -} - -static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev) -{ - int r; - uint64_t key = dev; - struct dm_thin_device *td; - - /* TODO: failure should mark the transaction invalid */ - r = __open_device(pmd, dev, 0, &td); - if (r) - return r; - - if (td->open_count > 1) { - __close_device(td); - return -EBUSY; - } - - list_del(&td->list); - kfree(td); - r = dm_btree_remove(&pmd->details_info, pmd->details_root, - &key, &pmd->details_root); - if (r) - return r; - - r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); - if (r) - return r; - - pmd->need_commit = 1; - - return 0; -} - -int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, - dm_thin_id dev) -{ - int r; - - down_write(&pmd->root_lock); - r = __delete_device(pmd, dev); - up_write(&pmd->root_lock); - - return r; -} - -int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, - uint64_t current_id, - uint64_t new_id) -{ - down_write(&pmd->root_lock); - if (pmd->trans_id != current_id) { - up_write(&pmd->root_lock); - DMERR("mismatched transaction id"); - return -EINVAL; - } - - pmd->trans_id = new_id; - pmd->need_commit = 1; - up_write(&pmd->root_lock); - - return 0; -} - -int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, - uint64_t *result) -{ - down_read(&pmd->root_lock); - *result = pmd->trans_id; - up_read(&pmd->root_lock); - - return 0; -} - -static int __get_held_metadata_root(struct dm_pool_metadata *pmd, - dm_block_t *result) -{ - int r; - struct thin_disk_superblock *disk_super; - struct dm_block *sblock; - - r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &sblock); - if (r) - return r; - - disk_super = dm_block_data(sblock); - *result = le64_to_cpu(disk_super->held_root); - - return dm_bm_unlock(sblock); -} - -int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd, - dm_block_t *result) -{ - int r; - - down_read(&pmd->root_lock); - r = __get_held_metadata_root(pmd, result); - up_read(&pmd->root_lock); - - return r; -} - -int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, - struct dm_thin_device **td) -{ - int r; - - down_write(&pmd->root_lock); - r = __open_device(pmd, dev, 0, td); - up_write(&pmd->root_lock); - - return r; -} - -int dm_pool_close_thin_device(struct dm_thin_device *td) -{ - down_write(&td->pmd->root_lock); - __close_device(td); - up_write(&td->pmd->root_lock); - - return 0; -} - -dm_thin_id dm_thin_dev_id(struct dm_thin_device *td) -{ - return td->id; -} - -static int __snapshotted_since(struct dm_thin_device *td, uint32_t time) -{ - return td->snapshotted_time > time; -} - -int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, - int can_block, struct dm_thin_lookup_result *result) -{ - int r; - uint64_t block_time = 0; - __le64 value; - struct dm_pool_metadata *pmd = td->pmd; - dm_block_t keys[2] = { td->id, block }; - - if (can_block) { - down_read(&pmd->root_lock); - r = dm_btree_lookup(&pmd->info, pmd->root, keys, &value); - if (!r) - block_time = le64_to_cpu(value); - up_read(&pmd->root_lock); - - } else if (down_read_trylock(&pmd->root_lock)) { - r = dm_btree_lookup(&pmd->nb_info, pmd->root, keys, &value); - if (!r) - block_time = le64_to_cpu(value); - up_read(&pmd->root_lock); - - } else - return -EWOULDBLOCK; - - if (!r) { - dm_block_t exception_block; - uint32_t exception_time; - unpack_block_time(block_time, &exception_block, - &exception_time); - result->block = exception_block; - result->shared = __snapshotted_since(td, exception_time); - } - - return r; -} - -static int __insert(struct dm_thin_device *td, dm_block_t block, - dm_block_t data_block) -{ - int r, inserted; - __le64 value; - struct dm_pool_metadata *pmd = td->pmd; - dm_block_t keys[2] = { td->id, block }; - - pmd->need_commit = 1; - value = cpu_to_le64(pack_block_time(data_block, pmd->time)); - __dm_bless_for_disk(&value); - - r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value, - &pmd->root, &inserted); - if (r) - return r; - - if (inserted) { - td->mapped_blocks++; - td->changed = 1; - } - - return 0; -} - -int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, - dm_block_t data_block) -{ - int r; - - down_write(&td->pmd->root_lock); - r = __insert(td, block, data_block); - up_write(&td->pmd->root_lock); - - return r; -} - -static int __remove(struct dm_thin_device *td, dm_block_t block) -{ - int r; - struct dm_pool_metadata *pmd = td->pmd; - dm_block_t keys[2] = { td->id, block }; - - r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root); - if (r) - return r; - - td->mapped_blocks--; - td->changed = 1; - pmd->need_commit = 1; - - return 0; -} - -int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block) -{ - int r; - - down_write(&td->pmd->root_lock); - r = __remove(td, block); - up_write(&td->pmd->root_lock); - - return r; -} - -int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result) -{ - int r; - - down_write(&pmd->root_lock); - - r = dm_sm_new_block(pmd->data_sm, result); - pmd->need_commit = 1; - - up_write(&pmd->root_lock); - - return r; -} - -int dm_pool_commit_metadata(struct dm_pool_metadata *pmd) -{ - int r; - - down_write(&pmd->root_lock); - - r = __commit_transaction(pmd); - if (r <= 0) - goto out; - - /* - * Open the next transaction. - */ - r = __begin_transaction(pmd); -out: - up_write(&pmd->root_lock); - return r; -} - -int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result) -{ - int r; - - down_read(&pmd->root_lock); - r = dm_sm_get_nr_free(pmd->data_sm, result); - up_read(&pmd->root_lock); - - return r; -} - -int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, - dm_block_t *result) -{ - int r; - - down_read(&pmd->root_lock); - r = dm_sm_get_nr_free(pmd->metadata_sm, result); - up_read(&pmd->root_lock); - - return r; -} - -int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, - dm_block_t *result) -{ - int r; - - down_read(&pmd->root_lock); - r = dm_sm_get_nr_blocks(pmd->metadata_sm, result); - up_read(&pmd->root_lock); - - return r; -} - -int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result) -{ - down_read(&pmd->root_lock); - *result = pmd->data_block_size; - up_read(&pmd->root_lock); - - return 0; -} - -int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result) -{ - int r; - - down_read(&pmd->root_lock); - r = dm_sm_get_nr_blocks(pmd->data_sm, result); - up_read(&pmd->root_lock); - - return r; -} - -int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result) -{ - struct dm_pool_metadata *pmd = td->pmd; - - down_read(&pmd->root_lock); - *result = td->mapped_blocks; - up_read(&pmd->root_lock); - - return 0; -} - -static int __highest_block(struct dm_thin_device *td, dm_block_t *result) -{ - int r; - __le64 value_le; - dm_block_t thin_root; - struct dm_pool_metadata *pmd = td->pmd; - - r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le); - if (r) - return r; - - thin_root = le64_to_cpu(value_le); - - return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result); -} - -int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, - dm_block_t *result) -{ - int r; - struct dm_pool_metadata *pmd = td->pmd; - - down_read(&pmd->root_lock); - r = __highest_block(td, result); - up_read(&pmd->root_lock); - - return r; -} - -static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) -{ - int r; - dm_block_t old_count; - - r = dm_sm_get_nr_blocks(pmd->data_sm, &old_count); - if (r) - return r; - - if (new_count == old_count) - return 0; - - if (new_count < old_count) { - DMERR("cannot reduce size of data device"); - return -EINVAL; - } - - r = dm_sm_extend(pmd->data_sm, new_count - old_count); - if (!r) - pmd->need_commit = 1; - - return r; -} - -int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) -{ - int r; - - down_write(&pmd->root_lock); - r = __resize_data_dev(pmd, new_count); - up_write(&pmd->root_lock); - - return r; -} |