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1821 lines
42 KiB
1821 lines
42 KiB
/* |
|
* Copyright (C) 2012 Red Hat, Inc. |
|
* |
|
* This file is released under the GPL. |
|
*/ |
|
|
|
#include "dm-cache-metadata.h" |
|
|
|
#include "persistent-data/dm-array.h" |
|
#include "persistent-data/dm-bitset.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/device-mapper.h> |
|
#include <linux/refcount.h> |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
#define DM_MSG_PREFIX "cache metadata" |
|
|
|
#define CACHE_SUPERBLOCK_MAGIC 06142003 |
|
#define CACHE_SUPERBLOCK_LOCATION 0 |
|
|
|
/* |
|
* defines a range of metadata versions that this module can handle. |
|
*/ |
|
#define MIN_CACHE_VERSION 1 |
|
#define MAX_CACHE_VERSION 2 |
|
|
|
/* |
|
* 3 for btree insert + |
|
* 2 for btree lookup used within space map |
|
*/ |
|
#define CACHE_MAX_CONCURRENT_LOCKS 5 |
|
#define SPACE_MAP_ROOT_SIZE 128 |
|
|
|
enum superblock_flag_bits { |
|
/* for spotting crashes that would invalidate the dirty bitset */ |
|
CLEAN_SHUTDOWN, |
|
/* metadata must be checked using the tools */ |
|
NEEDS_CHECK, |
|
}; |
|
|
|
/* |
|
* Each mapping from cache block -> origin block carries a set of flags. |
|
*/ |
|
enum mapping_bits { |
|
/* |
|
* A valid mapping. Because we're using an array we clear this |
|
* flag for an non existant mapping. |
|
*/ |
|
M_VALID = 1, |
|
|
|
/* |
|
* The data on the cache is different from that on the origin. |
|
* This flag is only used by metadata format 1. |
|
*/ |
|
M_DIRTY = 2 |
|
}; |
|
|
|
struct cache_disk_superblock { |
|
__le32 csum; |
|
__le32 flags; |
|
__le64 blocknr; |
|
|
|
__u8 uuid[16]; |
|
__le64 magic; |
|
__le32 version; |
|
|
|
__u8 policy_name[CACHE_POLICY_NAME_SIZE]; |
|
__le32 policy_hint_size; |
|
|
|
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
|
__le64 mapping_root; |
|
__le64 hint_root; |
|
|
|
__le64 discard_root; |
|
__le64 discard_block_size; |
|
__le64 discard_nr_blocks; |
|
|
|
__le32 data_block_size; |
|
__le32 metadata_block_size; |
|
__le32 cache_blocks; |
|
|
|
__le32 compat_flags; |
|
__le32 compat_ro_flags; |
|
__le32 incompat_flags; |
|
|
|
__le32 read_hits; |
|
__le32 read_misses; |
|
__le32 write_hits; |
|
__le32 write_misses; |
|
|
|
__le32 policy_version[CACHE_POLICY_VERSION_SIZE]; |
|
|
|
/* |
|
* Metadata format 2 fields. |
|
*/ |
|
__le64 dirty_root; |
|
} __packed; |
|
|
|
struct dm_cache_metadata { |
|
refcount_t ref_count; |
|
struct list_head list; |
|
|
|
unsigned version; |
|
struct block_device *bdev; |
|
struct dm_block_manager *bm; |
|
struct dm_space_map *metadata_sm; |
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struct dm_transaction_manager *tm; |
|
|
|
struct dm_array_info info; |
|
struct dm_array_info hint_info; |
|
struct dm_disk_bitset discard_info; |
|
|
|
struct rw_semaphore root_lock; |
|
unsigned long flags; |
|
dm_block_t root; |
|
dm_block_t hint_root; |
|
dm_block_t discard_root; |
|
|
|
sector_t discard_block_size; |
|
dm_dblock_t discard_nr_blocks; |
|
|
|
sector_t data_block_size; |
|
dm_cblock_t cache_blocks; |
|
bool changed:1; |
|
bool clean_when_opened:1; |
|
|
|
char policy_name[CACHE_POLICY_NAME_SIZE]; |
|
unsigned policy_version[CACHE_POLICY_VERSION_SIZE]; |
|
size_t policy_hint_size; |
|
struct dm_cache_statistics stats; |
|
|
|
/* |
|
* Reading the space map root can fail, so we read it into this |
|
* buffer before the superblock is locked and updated. |
|
*/ |
|
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
|
|
|
/* |
|
* Set if a transaction has to be aborted but the attempt to roll |
|
* back to the previous (good) transaction failed. The only |
|
* metadata operation permissible in this state is the closing of |
|
* the device. |
|
*/ |
|
bool fail_io:1; |
|
|
|
/* |
|
* Metadata format 2 fields. |
|
*/ |
|
dm_block_t dirty_root; |
|
struct dm_disk_bitset dirty_info; |
|
|
|
/* |
|
* These structures are used when loading metadata. They're too |
|
* big to put on the stack. |
|
*/ |
|
struct dm_array_cursor mapping_cursor; |
|
struct dm_array_cursor hint_cursor; |
|
struct dm_bitset_cursor dirty_cursor; |
|
}; |
|
|
|
/*------------------------------------------------------------------- |
|
* superblock validator |
|
*-----------------------------------------------------------------*/ |
|
|
|
#define SUPERBLOCK_CSUM_XOR 9031977 |
|
|
|
static void sb_prepare_for_write(struct dm_block_validator *v, |
|
struct dm_block *b, |
|
size_t sb_block_size) |
|
{ |
|
struct cache_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, |
|
sb_block_size - sizeof(__le32), |
|
SUPERBLOCK_CSUM_XOR)); |
|
} |
|
|
|
static int check_metadata_version(struct cache_disk_superblock *disk_super) |
|
{ |
|
uint32_t metadata_version = le32_to_cpu(disk_super->version); |
|
|
|
if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) { |
|
DMERR("Cache metadata version %u found, but only versions between %u and %u supported.", |
|
metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int sb_check(struct dm_block_validator *v, |
|
struct dm_block *b, |
|
size_t sb_block_size) |
|
{ |
|
struct cache_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) != CACHE_SUPERBLOCK_MAGIC) { |
|
DMERR("sb_check failed: magic %llu: wanted %llu", |
|
le64_to_cpu(disk_super->magic), |
|
(unsigned long long)CACHE_SUPERBLOCK_MAGIC); |
|
return -EILSEQ; |
|
} |
|
|
|
csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, |
|
sb_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 check_metadata_version(disk_super); |
|
} |
|
|
|
static struct dm_block_validator sb_validator = { |
|
.name = "superblock", |
|
.prepare_for_write = sb_prepare_for_write, |
|
.check = sb_check |
|
}; |
|
|
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/*----------------------------------------------------------------*/ |
|
|
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static int superblock_read_lock(struct dm_cache_metadata *cmd, |
|
struct dm_block **sblock) |
|
{ |
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return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
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&sb_validator, sblock); |
|
} |
|
|
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static int superblock_lock_zero(struct dm_cache_metadata *cmd, |
|
struct dm_block **sblock) |
|
{ |
|
return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
|
&sb_validator, sblock); |
|
} |
|
|
|
static int superblock_lock(struct dm_cache_metadata *cmd, |
|
struct dm_block **sblock) |
|
{ |
|
return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
|
&sb_validator, sblock); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result) |
|
{ |
|
int r; |
|
unsigned i; |
|
struct dm_block *b; |
|
__le64 *data_le, zero = cpu_to_le64(0); |
|
unsigned sb_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, CACHE_SUPERBLOCK_LOCATION, NULL, &b); |
|
if (r) |
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return r; |
|
|
|
data_le = dm_block_data(b); |
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*result = true; |
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for (i = 0; i < sb_block_size; i++) { |
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if (data_le[i] != zero) { |
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*result = false; |
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break; |
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} |
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} |
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|
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dm_bm_unlock(b); |
|
|
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return 0; |
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} |
|
|
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static void __setup_mapping_info(struct dm_cache_metadata *cmd) |
|
{ |
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struct dm_btree_value_type vt; |
|
|
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vt.context = NULL; |
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vt.size = sizeof(__le64); |
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vt.inc = NULL; |
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vt.dec = NULL; |
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vt.equal = NULL; |
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dm_array_info_init(&cmd->info, cmd->tm, &vt); |
|
|
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if (cmd->policy_hint_size) { |
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vt.size = sizeof(__le32); |
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dm_array_info_init(&cmd->hint_info, cmd->tm, &vt); |
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} |
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} |
|
|
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static int __save_sm_root(struct dm_cache_metadata *cmd) |
|
{ |
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int r; |
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size_t metadata_len; |
|
|
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r = dm_sm_root_size(cmd->metadata_sm, &metadata_len); |
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if (r < 0) |
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return r; |
|
|
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return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root, |
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metadata_len); |
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} |
|
|
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static void __copy_sm_root(struct dm_cache_metadata *cmd, |
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struct cache_disk_superblock *disk_super) |
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{ |
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memcpy(&disk_super->metadata_space_map_root, |
|
&cmd->metadata_space_map_root, |
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sizeof(cmd->metadata_space_map_root)); |
|
} |
|
|
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static bool separate_dirty_bits(struct dm_cache_metadata *cmd) |
|
{ |
|
return cmd->version >= 2; |
|
} |
|
|
|
static int __write_initial_superblock(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
struct cache_disk_superblock *disk_super; |
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sector_t bdev_size = bdev_nr_sectors(cmd->bdev); |
|
|
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/* FIXME: see if we can lose the max sectors limit */ |
|
if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS) |
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bdev_size = DM_CACHE_METADATA_MAX_SECTORS; |
|
|
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r = dm_tm_pre_commit(cmd->tm); |
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if (r < 0) |
|
return r; |
|
|
|
/* |
|
* dm_sm_copy_root() can fail. So we need to do it before we start |
|
* updating the superblock. |
|
*/ |
|
r = __save_sm_root(cmd); |
|
if (r) |
|
return r; |
|
|
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r = superblock_lock_zero(cmd, &sblock); |
|
if (r) |
|
return r; |
|
|
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disk_super = dm_block_data(sblock); |
|
disk_super->flags = 0; |
|
memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); |
|
disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC); |
|
disk_super->version = cpu_to_le32(cmd->version); |
|
memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); |
|
memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); |
|
disk_super->policy_hint_size = cpu_to_le32(0); |
|
|
|
__copy_sm_root(cmd, disk_super); |
|
|
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disk_super->mapping_root = cpu_to_le64(cmd->root); |
|
disk_super->hint_root = cpu_to_le64(cmd->hint_root); |
|
disk_super->discard_root = cpu_to_le64(cmd->discard_root); |
|
disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); |
|
disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); |
|
disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE); |
|
disk_super->data_block_size = cpu_to_le32(cmd->data_block_size); |
|
disk_super->cache_blocks = cpu_to_le32(0); |
|
|
|
disk_super->read_hits = cpu_to_le32(0); |
|
disk_super->read_misses = cpu_to_le32(0); |
|
disk_super->write_hits = cpu_to_le32(0); |
|
disk_super->write_misses = cpu_to_le32(0); |
|
|
|
if (separate_dirty_bits(cmd)) |
|
disk_super->dirty_root = cpu_to_le64(cmd->dirty_root); |
|
|
|
return dm_tm_commit(cmd->tm, sblock); |
|
} |
|
|
|
static int __format_metadata(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
|
|
r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
|
&cmd->tm, &cmd->metadata_sm); |
|
if (r < 0) { |
|
DMERR("tm_create_with_sm failed"); |
|
return r; |
|
} |
|
|
|
__setup_mapping_info(cmd); |
|
|
|
r = dm_array_empty(&cmd->info, &cmd->root); |
|
if (r < 0) |
|
goto bad; |
|
|
|
if (separate_dirty_bits(cmd)) { |
|
dm_disk_bitset_init(cmd->tm, &cmd->dirty_info); |
|
r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root); |
|
if (r < 0) |
|
goto bad; |
|
} |
|
|
|
dm_disk_bitset_init(cmd->tm, &cmd->discard_info); |
|
r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root); |
|
if (r < 0) |
|
goto bad; |
|
|
|
cmd->discard_block_size = 0; |
|
cmd->discard_nr_blocks = 0; |
|
|
|
r = __write_initial_superblock(cmd); |
|
if (r) |
|
goto bad; |
|
|
|
cmd->clean_when_opened = true; |
|
return 0; |
|
|
|
bad: |
|
dm_tm_destroy(cmd->tm); |
|
dm_sm_destroy(cmd->metadata_sm); |
|
|
|
return r; |
|
} |
|
|
|
static int __check_incompat_features(struct cache_disk_superblock *disk_super, |
|
struct dm_cache_metadata *cmd) |
|
{ |
|
uint32_t incompat_flags, features; |
|
|
|
incompat_flags = le32_to_cpu(disk_super->incompat_flags); |
|
features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP; |
|
if (features) { |
|
DMERR("could not access metadata due to unsupported optional features (%lx).", |
|
(unsigned long)features); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Check for read-only metadata to skip the following RDWR checks. |
|
*/ |
|
if (bdev_read_only(cmd->bdev)) |
|
return 0; |
|
|
|
features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP; |
|
if (features) { |
|
DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", |
|
(unsigned long)features); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int __open_metadata(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
struct cache_disk_superblock *disk_super; |
|
unsigned long sb_flags; |
|
|
|
r = superblock_read_lock(cmd, &sblock); |
|
if (r < 0) { |
|
DMERR("couldn't read lock superblock"); |
|
return r; |
|
} |
|
|
|
disk_super = dm_block_data(sblock); |
|
|
|
/* Verify the data block size hasn't changed */ |
|
if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { |
|
DMERR("changing the data block size (from %u to %llu) is not supported", |
|
le32_to_cpu(disk_super->data_block_size), |
|
(unsigned long long)cmd->data_block_size); |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
r = __check_incompat_features(disk_super, cmd); |
|
if (r < 0) |
|
goto bad; |
|
|
|
r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, |
|
disk_super->metadata_space_map_root, |
|
sizeof(disk_super->metadata_space_map_root), |
|
&cmd->tm, &cmd->metadata_sm); |
|
if (r < 0) { |
|
DMERR("tm_open_with_sm failed"); |
|
goto bad; |
|
} |
|
|
|
__setup_mapping_info(cmd); |
|
dm_disk_bitset_init(cmd->tm, &cmd->dirty_info); |
|
dm_disk_bitset_init(cmd->tm, &cmd->discard_info); |
|
sb_flags = le32_to_cpu(disk_super->flags); |
|
cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags); |
|
dm_bm_unlock(sblock); |
|
|
|
return 0; |
|
|
|
bad: |
|
dm_bm_unlock(sblock); |
|
return r; |
|
} |
|
|
|
static int __open_or_format_metadata(struct dm_cache_metadata *cmd, |
|
bool format_device) |
|
{ |
|
int r; |
|
bool unformatted = false; |
|
|
|
r = __superblock_all_zeroes(cmd->bm, &unformatted); |
|
if (r) |
|
return r; |
|
|
|
if (unformatted) |
|
return format_device ? __format_metadata(cmd) : -EPERM; |
|
|
|
return __open_metadata(cmd); |
|
} |
|
|
|
static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, |
|
bool may_format_device) |
|
{ |
|
int r; |
|
cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, |
|
CACHE_MAX_CONCURRENT_LOCKS); |
|
if (IS_ERR(cmd->bm)) { |
|
DMERR("could not create block manager"); |
|
r = PTR_ERR(cmd->bm); |
|
cmd->bm = NULL; |
|
return r; |
|
} |
|
|
|
r = __open_or_format_metadata(cmd, may_format_device); |
|
if (r) { |
|
dm_block_manager_destroy(cmd->bm); |
|
cmd->bm = NULL; |
|
} |
|
|
|
return r; |
|
} |
|
|
|
static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) |
|
{ |
|
dm_sm_destroy(cmd->metadata_sm); |
|
dm_tm_destroy(cmd->tm); |
|
dm_block_manager_destroy(cmd->bm); |
|
} |
|
|
|
typedef unsigned long (*flags_mutator)(unsigned long); |
|
|
|
static void update_flags(struct cache_disk_superblock *disk_super, |
|
flags_mutator mutator) |
|
{ |
|
uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags)); |
|
disk_super->flags = cpu_to_le32(sb_flags); |
|
} |
|
|
|
static unsigned long set_clean_shutdown(unsigned long flags) |
|
{ |
|
set_bit(CLEAN_SHUTDOWN, &flags); |
|
return flags; |
|
} |
|
|
|
static unsigned long clear_clean_shutdown(unsigned long flags) |
|
{ |
|
clear_bit(CLEAN_SHUTDOWN, &flags); |
|
return flags; |
|
} |
|
|
|
static void read_superblock_fields(struct dm_cache_metadata *cmd, |
|
struct cache_disk_superblock *disk_super) |
|
{ |
|
cmd->version = le32_to_cpu(disk_super->version); |
|
cmd->flags = le32_to_cpu(disk_super->flags); |
|
cmd->root = le64_to_cpu(disk_super->mapping_root); |
|
cmd->hint_root = le64_to_cpu(disk_super->hint_root); |
|
cmd->discard_root = le64_to_cpu(disk_super->discard_root); |
|
cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size); |
|
cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks)); |
|
cmd->data_block_size = le32_to_cpu(disk_super->data_block_size); |
|
cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks)); |
|
strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name)); |
|
cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]); |
|
cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]); |
|
cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]); |
|
cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size); |
|
|
|
cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits); |
|
cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses); |
|
cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits); |
|
cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses); |
|
|
|
if (separate_dirty_bits(cmd)) |
|
cmd->dirty_root = le64_to_cpu(disk_super->dirty_root); |
|
|
|
cmd->changed = false; |
|
} |
|
|
|
/* |
|
* The mutator updates the superblock flags. |
|
*/ |
|
static int __begin_transaction_flags(struct dm_cache_metadata *cmd, |
|
flags_mutator mutator) |
|
{ |
|
int r; |
|
struct cache_disk_superblock *disk_super; |
|
struct dm_block *sblock; |
|
|
|
r = superblock_lock(cmd, &sblock); |
|
if (r) |
|
return r; |
|
|
|
disk_super = dm_block_data(sblock); |
|
update_flags(disk_super, mutator); |
|
read_superblock_fields(cmd, disk_super); |
|
dm_bm_unlock(sblock); |
|
|
|
return dm_bm_flush(cmd->bm); |
|
} |
|
|
|
static int __begin_transaction(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
struct cache_disk_superblock *disk_super; |
|
struct dm_block *sblock; |
|
|
|
/* |
|
* We re-read the superblock every time. Shouldn't need to do this |
|
* really. |
|
*/ |
|
r = superblock_read_lock(cmd, &sblock); |
|
if (r) |
|
return r; |
|
|
|
disk_super = dm_block_data(sblock); |
|
read_superblock_fields(cmd, disk_super); |
|
dm_bm_unlock(sblock); |
|
|
|
return 0; |
|
} |
|
|
|
static int __commit_transaction(struct dm_cache_metadata *cmd, |
|
flags_mutator mutator) |
|
{ |
|
int r; |
|
struct cache_disk_superblock *disk_super; |
|
struct dm_block *sblock; |
|
|
|
/* |
|
* We need to know if the cache_disk_superblock exceeds a 512-byte sector. |
|
*/ |
|
BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512); |
|
|
|
if (separate_dirty_bits(cmd)) { |
|
r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root, |
|
&cmd->dirty_root); |
|
if (r) |
|
return r; |
|
} |
|
|
|
r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, |
|
&cmd->discard_root); |
|
if (r) |
|
return r; |
|
|
|
r = dm_tm_pre_commit(cmd->tm); |
|
if (r < 0) |
|
return r; |
|
|
|
r = __save_sm_root(cmd); |
|
if (r) |
|
return r; |
|
|
|
r = superblock_lock(cmd, &sblock); |
|
if (r) |
|
return r; |
|
|
|
disk_super = dm_block_data(sblock); |
|
|
|
disk_super->flags = cpu_to_le32(cmd->flags); |
|
if (mutator) |
|
update_flags(disk_super, mutator); |
|
|
|
disk_super->mapping_root = cpu_to_le64(cmd->root); |
|
if (separate_dirty_bits(cmd)) |
|
disk_super->dirty_root = cpu_to_le64(cmd->dirty_root); |
|
disk_super->hint_root = cpu_to_le64(cmd->hint_root); |
|
disk_super->discard_root = cpu_to_le64(cmd->discard_root); |
|
disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); |
|
disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); |
|
disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks)); |
|
strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name)); |
|
disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); |
|
disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); |
|
disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); |
|
disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size); |
|
|
|
disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); |
|
disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); |
|
disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits); |
|
disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses); |
|
__copy_sm_root(cmd, disk_super); |
|
|
|
return dm_tm_commit(cmd->tm, sblock); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
/* |
|
* The mappings are held in a dm-array that has 64-bit values stored in |
|
* little-endian format. The index is the cblock, the high 48bits of the |
|
* value are the oblock and the low 16 bit the flags. |
|
*/ |
|
#define FLAGS_MASK ((1 << 16) - 1) |
|
|
|
static __le64 pack_value(dm_oblock_t block, unsigned flags) |
|
{ |
|
uint64_t value = from_oblock(block); |
|
value <<= 16; |
|
value = value | (flags & FLAGS_MASK); |
|
return cpu_to_le64(value); |
|
} |
|
|
|
static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags) |
|
{ |
|
uint64_t value = le64_to_cpu(value_le); |
|
uint64_t b = value >> 16; |
|
*block = to_oblock(b); |
|
*flags = value & FLAGS_MASK; |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static struct dm_cache_metadata *metadata_open(struct block_device *bdev, |
|
sector_t data_block_size, |
|
bool may_format_device, |
|
size_t policy_hint_size, |
|
unsigned metadata_version) |
|
{ |
|
int r; |
|
struct dm_cache_metadata *cmd; |
|
|
|
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); |
|
if (!cmd) { |
|
DMERR("could not allocate metadata struct"); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
cmd->version = metadata_version; |
|
refcount_set(&cmd->ref_count, 1); |
|
init_rwsem(&cmd->root_lock); |
|
cmd->bdev = bdev; |
|
cmd->data_block_size = data_block_size; |
|
cmd->cache_blocks = 0; |
|
cmd->policy_hint_size = policy_hint_size; |
|
cmd->changed = true; |
|
cmd->fail_io = false; |
|
|
|
r = __create_persistent_data_objects(cmd, may_format_device); |
|
if (r) { |
|
kfree(cmd); |
|
return ERR_PTR(r); |
|
} |
|
|
|
r = __begin_transaction_flags(cmd, clear_clean_shutdown); |
|
if (r < 0) { |
|
dm_cache_metadata_close(cmd); |
|
return ERR_PTR(r); |
|
} |
|
|
|
return cmd; |
|
} |
|
|
|
/* |
|
* We keep a little list of ref counted metadata objects to prevent two |
|
* different target instances creating separate bufio instances. This is |
|
* an issue if a table is reloaded before the suspend. |
|
*/ |
|
static DEFINE_MUTEX(table_lock); |
|
static LIST_HEAD(table); |
|
|
|
static struct dm_cache_metadata *lookup(struct block_device *bdev) |
|
{ |
|
struct dm_cache_metadata *cmd; |
|
|
|
list_for_each_entry(cmd, &table, list) |
|
if (cmd->bdev == bdev) { |
|
refcount_inc(&cmd->ref_count); |
|
return cmd; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev, |
|
sector_t data_block_size, |
|
bool may_format_device, |
|
size_t policy_hint_size, |
|
unsigned metadata_version) |
|
{ |
|
struct dm_cache_metadata *cmd, *cmd2; |
|
|
|
mutex_lock(&table_lock); |
|
cmd = lookup(bdev); |
|
mutex_unlock(&table_lock); |
|
|
|
if (cmd) |
|
return cmd; |
|
|
|
cmd = metadata_open(bdev, data_block_size, may_format_device, |
|
policy_hint_size, metadata_version); |
|
if (!IS_ERR(cmd)) { |
|
mutex_lock(&table_lock); |
|
cmd2 = lookup(bdev); |
|
if (cmd2) { |
|
mutex_unlock(&table_lock); |
|
__destroy_persistent_data_objects(cmd); |
|
kfree(cmd); |
|
return cmd2; |
|
} |
|
list_add(&cmd->list, &table); |
|
mutex_unlock(&table_lock); |
|
} |
|
|
|
return cmd; |
|
} |
|
|
|
static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size) |
|
{ |
|
if (cmd->data_block_size != data_block_size) { |
|
DMERR("data_block_size (%llu) different from that in metadata (%llu)", |
|
(unsigned long long) data_block_size, |
|
(unsigned long long) cmd->data_block_size); |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, |
|
sector_t data_block_size, |
|
bool may_format_device, |
|
size_t policy_hint_size, |
|
unsigned metadata_version) |
|
{ |
|
struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device, |
|
policy_hint_size, metadata_version); |
|
|
|
if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) { |
|
dm_cache_metadata_close(cmd); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
return cmd; |
|
} |
|
|
|
void dm_cache_metadata_close(struct dm_cache_metadata *cmd) |
|
{ |
|
if (refcount_dec_and_test(&cmd->ref_count)) { |
|
mutex_lock(&table_lock); |
|
list_del(&cmd->list); |
|
mutex_unlock(&table_lock); |
|
|
|
if (!cmd->fail_io) |
|
__destroy_persistent_data_objects(cmd); |
|
kfree(cmd); |
|
} |
|
} |
|
|
|
/* |
|
* Checks that the given cache block is either unmapped or clean. |
|
*/ |
|
static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b, |
|
bool *result) |
|
{ |
|
int r; |
|
__le64 value; |
|
dm_oblock_t ob; |
|
unsigned flags; |
|
|
|
r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); |
|
if (r) |
|
return r; |
|
|
|
unpack_value(value, &ob, &flags); |
|
*result = !((flags & M_VALID) && (flags & M_DIRTY)); |
|
|
|
return 0; |
|
} |
|
|
|
static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd, |
|
dm_cblock_t begin, dm_cblock_t end, |
|
bool *result) |
|
{ |
|
int r; |
|
*result = true; |
|
|
|
while (begin != end) { |
|
r = block_clean_combined_dirty(cmd, begin, result); |
|
if (r) { |
|
DMERR("block_clean_combined_dirty failed"); |
|
return r; |
|
} |
|
|
|
if (!*result) { |
|
DMERR("cache block %llu is dirty", |
|
(unsigned long long) from_cblock(begin)); |
|
return 0; |
|
} |
|
|
|
begin = to_cblock(from_cblock(begin) + 1); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd, |
|
dm_cblock_t begin, dm_cblock_t end, |
|
bool *result) |
|
{ |
|
int r; |
|
bool dirty_flag; |
|
*result = true; |
|
|
|
if (from_cblock(cmd->cache_blocks) == 0) |
|
/* Nothing to do */ |
|
return 0; |
|
|
|
r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root, |
|
from_cblock(cmd->cache_blocks), &cmd->dirty_cursor); |
|
if (r) { |
|
DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__); |
|
return r; |
|
} |
|
|
|
r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin)); |
|
if (r) { |
|
DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__); |
|
dm_bitset_cursor_end(&cmd->dirty_cursor); |
|
return r; |
|
} |
|
|
|
while (begin != end) { |
|
/* |
|
* We assume that unmapped blocks have their dirty bit |
|
* cleared. |
|
*/ |
|
dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor); |
|
if (dirty_flag) { |
|
DMERR("%s: cache block %llu is dirty", __func__, |
|
(unsigned long long) from_cblock(begin)); |
|
dm_bitset_cursor_end(&cmd->dirty_cursor); |
|
*result = false; |
|
return 0; |
|
} |
|
|
|
begin = to_cblock(from_cblock(begin) + 1); |
|
if (begin == end) |
|
break; |
|
|
|
r = dm_bitset_cursor_next(&cmd->dirty_cursor); |
|
if (r) { |
|
DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__); |
|
dm_bitset_cursor_end(&cmd->dirty_cursor); |
|
return r; |
|
} |
|
} |
|
|
|
dm_bitset_cursor_end(&cmd->dirty_cursor); |
|
|
|
return 0; |
|
} |
|
|
|
static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, |
|
dm_cblock_t begin, dm_cblock_t end, |
|
bool *result) |
|
{ |
|
if (separate_dirty_bits(cmd)) |
|
return blocks_are_clean_separate_dirty(cmd, begin, end, result); |
|
else |
|
return blocks_are_clean_combined_dirty(cmd, begin, end, result); |
|
} |
|
|
|
static bool cmd_write_lock(struct dm_cache_metadata *cmd) |
|
{ |
|
down_write(&cmd->root_lock); |
|
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { |
|
up_write(&cmd->root_lock); |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
#define WRITE_LOCK(cmd) \ |
|
do { \ |
|
if (!cmd_write_lock((cmd))) \ |
|
return -EINVAL; \ |
|
} while(0) |
|
|
|
#define WRITE_LOCK_VOID(cmd) \ |
|
do { \ |
|
if (!cmd_write_lock((cmd))) \ |
|
return; \ |
|
} while(0) |
|
|
|
#define WRITE_UNLOCK(cmd) \ |
|
up_write(&(cmd)->root_lock) |
|
|
|
static bool cmd_read_lock(struct dm_cache_metadata *cmd) |
|
{ |
|
down_read(&cmd->root_lock); |
|
if (cmd->fail_io) { |
|
up_read(&cmd->root_lock); |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
#define READ_LOCK(cmd) \ |
|
do { \ |
|
if (!cmd_read_lock((cmd))) \ |
|
return -EINVAL; \ |
|
} while(0) |
|
|
|
#define READ_LOCK_VOID(cmd) \ |
|
do { \ |
|
if (!cmd_read_lock((cmd))) \ |
|
return; \ |
|
} while(0) |
|
|
|
#define READ_UNLOCK(cmd) \ |
|
up_read(&(cmd)->root_lock) |
|
|
|
int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) |
|
{ |
|
int r; |
|
bool clean; |
|
__le64 null_mapping = pack_value(0, 0); |
|
|
|
WRITE_LOCK(cmd); |
|
__dm_bless_for_disk(&null_mapping); |
|
|
|
if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { |
|
r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); |
|
if (r) { |
|
__dm_unbless_for_disk(&null_mapping); |
|
goto out; |
|
} |
|
|
|
if (!clean) { |
|
DMERR("unable to shrink cache due to dirty blocks"); |
|
r = -EINVAL; |
|
__dm_unbless_for_disk(&null_mapping); |
|
goto out; |
|
} |
|
} |
|
|
|
r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), |
|
from_cblock(new_cache_size), |
|
&null_mapping, &cmd->root); |
|
if (r) |
|
goto out; |
|
|
|
if (separate_dirty_bits(cmd)) { |
|
r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root, |
|
from_cblock(cmd->cache_blocks), from_cblock(new_cache_size), |
|
false, &cmd->dirty_root); |
|
if (r) |
|
goto out; |
|
} |
|
|
|
cmd->cache_blocks = new_cache_size; |
|
cmd->changed = true; |
|
|
|
out: |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, |
|
sector_t discard_block_size, |
|
dm_dblock_t new_nr_entries) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
r = dm_bitset_resize(&cmd->discard_info, |
|
cmd->discard_root, |
|
from_dblock(cmd->discard_nr_blocks), |
|
from_dblock(new_nr_entries), |
|
false, &cmd->discard_root); |
|
if (!r) { |
|
cmd->discard_block_size = discard_block_size; |
|
cmd->discard_nr_blocks = new_nr_entries; |
|
} |
|
|
|
cmd->changed = true; |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) |
|
{ |
|
return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root, |
|
from_dblock(b), &cmd->discard_root); |
|
} |
|
|
|
static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) |
|
{ |
|
return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root, |
|
from_dblock(b), &cmd->discard_root); |
|
} |
|
|
|
static int __discard(struct dm_cache_metadata *cmd, |
|
dm_dblock_t dblock, bool discard) |
|
{ |
|
int r; |
|
|
|
r = (discard ? __set_discard : __clear_discard)(cmd, dblock); |
|
if (r) |
|
return r; |
|
|
|
cmd->changed = true; |
|
return 0; |
|
} |
|
|
|
int dm_cache_set_discard(struct dm_cache_metadata *cmd, |
|
dm_dblock_t dblock, bool discard) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
r = __discard(cmd, dblock, discard); |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
static int __load_discards(struct dm_cache_metadata *cmd, |
|
load_discard_fn fn, void *context) |
|
{ |
|
int r = 0; |
|
uint32_t b; |
|
struct dm_bitset_cursor c; |
|
|
|
if (from_dblock(cmd->discard_nr_blocks) == 0) |
|
/* nothing to do */ |
|
return 0; |
|
|
|
if (cmd->clean_when_opened) { |
|
r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root); |
|
if (r) |
|
return r; |
|
|
|
r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root, |
|
from_dblock(cmd->discard_nr_blocks), &c); |
|
if (r) |
|
return r; |
|
|
|
for (b = 0; ; b++) { |
|
r = fn(context, cmd->discard_block_size, to_dblock(b), |
|
dm_bitset_cursor_get_value(&c)); |
|
if (r) |
|
break; |
|
|
|
if (b >= (from_dblock(cmd->discard_nr_blocks) - 1)) |
|
break; |
|
|
|
r = dm_bitset_cursor_next(&c); |
|
if (r) |
|
break; |
|
} |
|
|
|
dm_bitset_cursor_end(&c); |
|
|
|
} else { |
|
for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) { |
|
r = fn(context, cmd->discard_block_size, to_dblock(b), false); |
|
if (r) |
|
return r; |
|
} |
|
} |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_load_discards(struct dm_cache_metadata *cmd, |
|
load_discard_fn fn, void *context) |
|
{ |
|
int r; |
|
|
|
READ_LOCK(cmd); |
|
r = __load_discards(cmd, fn, context); |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result) |
|
{ |
|
READ_LOCK(cmd); |
|
*result = cmd->cache_blocks; |
|
READ_UNLOCK(cmd); |
|
|
|
return 0; |
|
} |
|
|
|
static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) |
|
{ |
|
int r; |
|
__le64 value = pack_value(0, 0); |
|
|
|
__dm_bless_for_disk(&value); |
|
r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
|
&value, &cmd->root); |
|
if (r) |
|
return r; |
|
|
|
cmd->changed = true; |
|
return 0; |
|
} |
|
|
|
int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
r = __remove(cmd, cblock); |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
static int __insert(struct dm_cache_metadata *cmd, |
|
dm_cblock_t cblock, dm_oblock_t oblock) |
|
{ |
|
int r; |
|
__le64 value = pack_value(oblock, M_VALID); |
|
__dm_bless_for_disk(&value); |
|
|
|
r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
|
&value, &cmd->root); |
|
if (r) |
|
return r; |
|
|
|
cmd->changed = true; |
|
return 0; |
|
} |
|
|
|
int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, |
|
dm_cblock_t cblock, dm_oblock_t oblock) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
r = __insert(cmd, cblock, oblock); |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
struct thunk { |
|
load_mapping_fn fn; |
|
void *context; |
|
|
|
struct dm_cache_metadata *cmd; |
|
bool respect_dirty_flags; |
|
bool hints_valid; |
|
}; |
|
|
|
static bool policy_unchanged(struct dm_cache_metadata *cmd, |
|
struct dm_cache_policy *policy) |
|
{ |
|
const char *policy_name = dm_cache_policy_get_name(policy); |
|
const unsigned *policy_version = dm_cache_policy_get_version(policy); |
|
size_t policy_hint_size = dm_cache_policy_get_hint_size(policy); |
|
|
|
/* |
|
* Ensure policy names match. |
|
*/ |
|
if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name))) |
|
return false; |
|
|
|
/* |
|
* Ensure policy major versions match. |
|
*/ |
|
if (cmd->policy_version[0] != policy_version[0]) |
|
return false; |
|
|
|
/* |
|
* Ensure policy hint sizes match. |
|
*/ |
|
if (cmd->policy_hint_size != policy_hint_size) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
static bool hints_array_initialized(struct dm_cache_metadata *cmd) |
|
{ |
|
return cmd->hint_root && cmd->policy_hint_size; |
|
} |
|
|
|
static bool hints_array_available(struct dm_cache_metadata *cmd, |
|
struct dm_cache_policy *policy) |
|
{ |
|
return cmd->clean_when_opened && policy_unchanged(cmd, policy) && |
|
hints_array_initialized(cmd); |
|
} |
|
|
|
static int __load_mapping_v1(struct dm_cache_metadata *cmd, |
|
uint64_t cb, bool hints_valid, |
|
struct dm_array_cursor *mapping_cursor, |
|
struct dm_array_cursor *hint_cursor, |
|
load_mapping_fn fn, void *context) |
|
{ |
|
int r = 0; |
|
|
|
__le64 mapping; |
|
__le32 hint = 0; |
|
|
|
__le64 *mapping_value_le; |
|
__le32 *hint_value_le; |
|
|
|
dm_oblock_t oblock; |
|
unsigned flags; |
|
bool dirty = true; |
|
|
|
dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le); |
|
memcpy(&mapping, mapping_value_le, sizeof(mapping)); |
|
unpack_value(mapping, &oblock, &flags); |
|
|
|
if (flags & M_VALID) { |
|
if (hints_valid) { |
|
dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le); |
|
memcpy(&hint, hint_value_le, sizeof(hint)); |
|
} |
|
if (cmd->clean_when_opened) |
|
dirty = flags & M_DIRTY; |
|
|
|
r = fn(context, oblock, to_cblock(cb), dirty, |
|
le32_to_cpu(hint), hints_valid); |
|
if (r) { |
|
DMERR("policy couldn't load cache block %llu", |
|
(unsigned long long) from_cblock(to_cblock(cb))); |
|
} |
|
} |
|
|
|
return r; |
|
} |
|
|
|
static int __load_mapping_v2(struct dm_cache_metadata *cmd, |
|
uint64_t cb, bool hints_valid, |
|
struct dm_array_cursor *mapping_cursor, |
|
struct dm_array_cursor *hint_cursor, |
|
struct dm_bitset_cursor *dirty_cursor, |
|
load_mapping_fn fn, void *context) |
|
{ |
|
int r = 0; |
|
|
|
__le64 mapping; |
|
__le32 hint = 0; |
|
|
|
__le64 *mapping_value_le; |
|
__le32 *hint_value_le; |
|
|
|
dm_oblock_t oblock; |
|
unsigned flags; |
|
bool dirty = true; |
|
|
|
dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le); |
|
memcpy(&mapping, mapping_value_le, sizeof(mapping)); |
|
unpack_value(mapping, &oblock, &flags); |
|
|
|
if (flags & M_VALID) { |
|
if (hints_valid) { |
|
dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le); |
|
memcpy(&hint, hint_value_le, sizeof(hint)); |
|
} |
|
if (cmd->clean_when_opened) |
|
dirty = dm_bitset_cursor_get_value(dirty_cursor); |
|
|
|
r = fn(context, oblock, to_cblock(cb), dirty, |
|
le32_to_cpu(hint), hints_valid); |
|
if (r) { |
|
DMERR("policy couldn't load cache block %llu", |
|
(unsigned long long) from_cblock(to_cblock(cb))); |
|
} |
|
} |
|
|
|
return r; |
|
} |
|
|
|
static int __load_mappings(struct dm_cache_metadata *cmd, |
|
struct dm_cache_policy *policy, |
|
load_mapping_fn fn, void *context) |
|
{ |
|
int r; |
|
uint64_t cb; |
|
|
|
bool hints_valid = hints_array_available(cmd, policy); |
|
|
|
if (from_cblock(cmd->cache_blocks) == 0) |
|
/* Nothing to do */ |
|
return 0; |
|
|
|
r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor); |
|
if (r) |
|
return r; |
|
|
|
if (hints_valid) { |
|
r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor); |
|
if (r) { |
|
dm_array_cursor_end(&cmd->mapping_cursor); |
|
return r; |
|
} |
|
} |
|
|
|
if (separate_dirty_bits(cmd)) { |
|
r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root, |
|
from_cblock(cmd->cache_blocks), |
|
&cmd->dirty_cursor); |
|
if (r) { |
|
dm_array_cursor_end(&cmd->hint_cursor); |
|
dm_array_cursor_end(&cmd->mapping_cursor); |
|
return r; |
|
} |
|
} |
|
|
|
for (cb = 0; ; cb++) { |
|
if (separate_dirty_bits(cmd)) |
|
r = __load_mapping_v2(cmd, cb, hints_valid, |
|
&cmd->mapping_cursor, |
|
&cmd->hint_cursor, |
|
&cmd->dirty_cursor, |
|
fn, context); |
|
else |
|
r = __load_mapping_v1(cmd, cb, hints_valid, |
|
&cmd->mapping_cursor, &cmd->hint_cursor, |
|
fn, context); |
|
if (r) |
|
goto out; |
|
|
|
/* |
|
* We need to break out before we move the cursors. |
|
*/ |
|
if (cb >= (from_cblock(cmd->cache_blocks) - 1)) |
|
break; |
|
|
|
r = dm_array_cursor_next(&cmd->mapping_cursor); |
|
if (r) { |
|
DMERR("dm_array_cursor_next for mapping failed"); |
|
goto out; |
|
} |
|
|
|
if (hints_valid) { |
|
r = dm_array_cursor_next(&cmd->hint_cursor); |
|
if (r) { |
|
dm_array_cursor_end(&cmd->hint_cursor); |
|
hints_valid = false; |
|
} |
|
} |
|
|
|
if (separate_dirty_bits(cmd)) { |
|
r = dm_bitset_cursor_next(&cmd->dirty_cursor); |
|
if (r) { |
|
DMERR("dm_bitset_cursor_next for dirty failed"); |
|
goto out; |
|
} |
|
} |
|
} |
|
out: |
|
dm_array_cursor_end(&cmd->mapping_cursor); |
|
if (hints_valid) |
|
dm_array_cursor_end(&cmd->hint_cursor); |
|
|
|
if (separate_dirty_bits(cmd)) |
|
dm_bitset_cursor_end(&cmd->dirty_cursor); |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_load_mappings(struct dm_cache_metadata *cmd, |
|
struct dm_cache_policy *policy, |
|
load_mapping_fn fn, void *context) |
|
{ |
|
int r; |
|
|
|
READ_LOCK(cmd); |
|
r = __load_mappings(cmd, policy, fn, context); |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
static int __dump_mapping(void *context, uint64_t cblock, void *leaf) |
|
{ |
|
int r = 0; |
|
__le64 value; |
|
dm_oblock_t oblock; |
|
unsigned flags; |
|
|
|
memcpy(&value, leaf, sizeof(value)); |
|
unpack_value(value, &oblock, &flags); |
|
|
|
return r; |
|
} |
|
|
|
static int __dump_mappings(struct dm_cache_metadata *cmd) |
|
{ |
|
return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL); |
|
} |
|
|
|
void dm_cache_dump(struct dm_cache_metadata *cmd) |
|
{ |
|
READ_LOCK_VOID(cmd); |
|
__dump_mappings(cmd); |
|
READ_UNLOCK(cmd); |
|
} |
|
|
|
int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
|
|
READ_LOCK(cmd); |
|
r = cmd->changed; |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty) |
|
{ |
|
int r; |
|
unsigned flags; |
|
dm_oblock_t oblock; |
|
__le64 value; |
|
|
|
r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value); |
|
if (r) |
|
return r; |
|
|
|
unpack_value(value, &oblock, &flags); |
|
|
|
if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty)) |
|
/* nothing to be done */ |
|
return 0; |
|
|
|
value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0)); |
|
__dm_bless_for_disk(&value); |
|
|
|
r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), |
|
&value, &cmd->root); |
|
if (r) |
|
return r; |
|
|
|
cmd->changed = true; |
|
return 0; |
|
|
|
} |
|
|
|
static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits) |
|
{ |
|
int r; |
|
unsigned i; |
|
for (i = 0; i < nr_bits; i++) { |
|
r = __dirty(cmd, to_cblock(i), test_bit(i, bits)); |
|
if (r) |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int is_dirty_callback(uint32_t index, bool *value, void *context) |
|
{ |
|
unsigned long *bits = context; |
|
*value = test_bit(index, bits); |
|
return 0; |
|
} |
|
|
|
static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits) |
|
{ |
|
int r = 0; |
|
|
|
/* nr_bits is really just a sanity check */ |
|
if (nr_bits != from_cblock(cmd->cache_blocks)) { |
|
DMERR("dirty bitset is wrong size"); |
|
return -EINVAL; |
|
} |
|
|
|
r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root); |
|
if (r) |
|
return r; |
|
|
|
cmd->changed = true; |
|
return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits); |
|
} |
|
|
|
int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd, |
|
unsigned nr_bits, |
|
unsigned long *bits) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
if (separate_dirty_bits(cmd)) |
|
r = __set_dirty_bits_v2(cmd, nr_bits, bits); |
|
else |
|
r = __set_dirty_bits_v1(cmd, nr_bits, bits); |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, |
|
struct dm_cache_statistics *stats) |
|
{ |
|
READ_LOCK_VOID(cmd); |
|
*stats = cmd->stats; |
|
READ_UNLOCK(cmd); |
|
} |
|
|
|
void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, |
|
struct dm_cache_statistics *stats) |
|
{ |
|
WRITE_LOCK_VOID(cmd); |
|
cmd->stats = *stats; |
|
WRITE_UNLOCK(cmd); |
|
} |
|
|
|
int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) |
|
{ |
|
int r = -EINVAL; |
|
flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : |
|
clear_clean_shutdown); |
|
|
|
WRITE_LOCK(cmd); |
|
if (cmd->fail_io) |
|
goto out; |
|
|
|
r = __commit_transaction(cmd, mutator); |
|
if (r) |
|
goto out; |
|
|
|
r = __begin_transaction(cmd); |
|
out: |
|
WRITE_UNLOCK(cmd); |
|
return r; |
|
} |
|
|
|
int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, |
|
dm_block_t *result) |
|
{ |
|
int r = -EINVAL; |
|
|
|
READ_LOCK(cmd); |
|
if (!cmd->fail_io) |
|
r = dm_sm_get_nr_free(cmd->metadata_sm, result); |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, |
|
dm_block_t *result) |
|
{ |
|
int r = -EINVAL; |
|
|
|
READ_LOCK(cmd); |
|
if (!cmd->fail_io) |
|
r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static int get_hint(uint32_t index, void *value_le, void *context) |
|
{ |
|
uint32_t value; |
|
struct dm_cache_policy *policy = context; |
|
|
|
value = policy_get_hint(policy, to_cblock(index)); |
|
*((__le32 *) value_le) = cpu_to_le32(value); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* It's quicker to always delete the hint array, and recreate with |
|
* dm_array_new(). |
|
*/ |
|
static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
|
{ |
|
int r; |
|
size_t hint_size; |
|
const char *policy_name = dm_cache_policy_get_name(policy); |
|
const unsigned *policy_version = dm_cache_policy_get_version(policy); |
|
|
|
if (!policy_name[0] || |
|
(strlen(policy_name) > sizeof(cmd->policy_name) - 1)) |
|
return -EINVAL; |
|
|
|
strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); |
|
memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); |
|
|
|
hint_size = dm_cache_policy_get_hint_size(policy); |
|
if (!hint_size) |
|
return 0; /* short-circuit hints initialization */ |
|
cmd->policy_hint_size = hint_size; |
|
|
|
if (cmd->hint_root) { |
|
r = dm_array_del(&cmd->hint_info, cmd->hint_root); |
|
if (r) |
|
return r; |
|
} |
|
|
|
return dm_array_new(&cmd->hint_info, &cmd->hint_root, |
|
from_cblock(cmd->cache_blocks), |
|
get_hint, policy); |
|
} |
|
|
|
int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
r = write_hints(cmd, policy); |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) |
|
{ |
|
int r; |
|
|
|
READ_LOCK(cmd); |
|
r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); |
|
READ_UNLOCK(cmd); |
|
|
|
return r; |
|
} |
|
|
|
void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd) |
|
{ |
|
WRITE_LOCK_VOID(cmd); |
|
dm_bm_set_read_only(cmd->bm); |
|
WRITE_UNLOCK(cmd); |
|
} |
|
|
|
void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd) |
|
{ |
|
WRITE_LOCK_VOID(cmd); |
|
dm_bm_set_read_write(cmd->bm); |
|
WRITE_UNLOCK(cmd); |
|
} |
|
|
|
int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
struct cache_disk_superblock *disk_super; |
|
|
|
WRITE_LOCK(cmd); |
|
set_bit(NEEDS_CHECK, &cmd->flags); |
|
|
|
r = superblock_lock(cmd, &sblock); |
|
if (r) { |
|
DMERR("couldn't read superblock"); |
|
goto out; |
|
} |
|
|
|
disk_super = dm_block_data(sblock); |
|
disk_super->flags = cpu_to_le32(cmd->flags); |
|
|
|
dm_bm_unlock(sblock); |
|
|
|
out: |
|
WRITE_UNLOCK(cmd); |
|
return r; |
|
} |
|
|
|
int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result) |
|
{ |
|
READ_LOCK(cmd); |
|
*result = !!test_bit(NEEDS_CHECK, &cmd->flags); |
|
READ_UNLOCK(cmd); |
|
|
|
return 0; |
|
} |
|
|
|
int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) |
|
{ |
|
int r; |
|
|
|
WRITE_LOCK(cmd); |
|
__destroy_persistent_data_objects(cmd); |
|
r = __create_persistent_data_objects(cmd, false); |
|
if (r) |
|
cmd->fail_io = true; |
|
WRITE_UNLOCK(cmd); |
|
|
|
return r; |
|
}
|
|
|