mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
6dcbb52cdd
Use the proper helpers to read the block device size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
1821 lines
42 KiB
C
1821 lines
42 KiB
C
/*
|
|
* 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;
|
|
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
|
|
};
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
static int superblock_read_lock(struct dm_cache_metadata *cmd,
|
|
struct dm_block **sblock)
|
|
{
|
|
return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
|
|
&sb_validator, sblock);
|
|
}
|
|
|
|
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)
|
|
return r;
|
|
|
|
data_le = dm_block_data(b);
|
|
*result = true;
|
|
for (i = 0; i < sb_block_size; i++) {
|
|
if (data_le[i] != zero) {
|
|
*result = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
dm_bm_unlock(b);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __setup_mapping_info(struct dm_cache_metadata *cmd)
|
|
{
|
|
struct dm_btree_value_type vt;
|
|
|
|
vt.context = NULL;
|
|
vt.size = sizeof(__le64);
|
|
vt.inc = NULL;
|
|
vt.dec = NULL;
|
|
vt.equal = NULL;
|
|
dm_array_info_init(&cmd->info, cmd->tm, &vt);
|
|
|
|
if (cmd->policy_hint_size) {
|
|
vt.size = sizeof(__le32);
|
|
dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
|
|
}
|
|
}
|
|
|
|
static int __save_sm_root(struct dm_cache_metadata *cmd)
|
|
{
|
|
int r;
|
|
size_t metadata_len;
|
|
|
|
r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
|
|
metadata_len);
|
|
}
|
|
|
|
static void __copy_sm_root(struct dm_cache_metadata *cmd,
|
|
struct cache_disk_superblock *disk_super)
|
|
{
|
|
memcpy(&disk_super->metadata_space_map_root,
|
|
&cmd->metadata_space_map_root,
|
|
sizeof(cmd->metadata_space_map_root));
|
|
}
|
|
|
|
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;
|
|
sector_t bdev_size = bdev_nr_sectors(cmd->bdev);
|
|
|
|
/* FIXME: see if we can lose the max sectors limit */
|
|
if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
|
|
bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
|
|
|
|
r = dm_tm_pre_commit(cmd->tm);
|
|
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;
|
|
|
|
r = superblock_lock_zero(cmd, &sblock);
|
|
if (r)
|
|
return r;
|
|
|
|
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);
|
|
|
|
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;
|
|
}
|