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1750 lines
38 KiB
1750 lines
38 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
#include "dm.h" |
|
#include "persistent-data/dm-transaction-manager.h" |
|
#include "persistent-data/dm-bitset.h" |
|
#include "persistent-data/dm-space-map.h" |
|
|
|
#include <linux/dm-io.h> |
|
#include <linux/dm-kcopyd.h> |
|
#include <linux/init.h> |
|
#include <linux/mempool.h> |
|
#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/vmalloc.h> |
|
|
|
#define DM_MSG_PREFIX "era" |
|
|
|
#define SUPERBLOCK_LOCATION 0 |
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#define SUPERBLOCK_MAGIC 2126579579 |
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#define SUPERBLOCK_CSUM_XOR 146538381 |
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#define MIN_ERA_VERSION 1 |
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#define MAX_ERA_VERSION 1 |
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#define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION |
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#define MIN_BLOCK_SIZE 8 |
|
|
|
/*---------------------------------------------------------------- |
|
* Writeset |
|
*--------------------------------------------------------------*/ |
|
struct writeset_metadata { |
|
uint32_t nr_bits; |
|
dm_block_t root; |
|
}; |
|
|
|
struct writeset { |
|
struct writeset_metadata md; |
|
|
|
/* |
|
* An in core copy of the bits to save constantly doing look ups on |
|
* disk. |
|
*/ |
|
unsigned long *bits; |
|
}; |
|
|
|
/* |
|
* This does not free off the on disk bitset as this will normally be done |
|
* after digesting into the era array. |
|
*/ |
|
static void writeset_free(struct writeset *ws) |
|
{ |
|
vfree(ws->bits); |
|
ws->bits = NULL; |
|
} |
|
|
|
static int setup_on_disk_bitset(struct dm_disk_bitset *info, |
|
unsigned nr_bits, dm_block_t *root) |
|
{ |
|
int r; |
|
|
|
r = dm_bitset_empty(info, root); |
|
if (r) |
|
return r; |
|
|
|
return dm_bitset_resize(info, *root, 0, nr_bits, false, root); |
|
} |
|
|
|
static size_t bitset_size(unsigned nr_bits) |
|
{ |
|
return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); |
|
} |
|
|
|
/* |
|
* Allocates memory for the in core bitset. |
|
*/ |
|
static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) |
|
{ |
|
ws->bits = vzalloc(bitset_size(nr_blocks)); |
|
if (!ws->bits) { |
|
DMERR("%s: couldn't allocate in memory bitset", __func__); |
|
return -ENOMEM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Wipes the in-core bitset, and creates a new on disk bitset. |
|
*/ |
|
static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws, |
|
dm_block_t nr_blocks) |
|
{ |
|
int r; |
|
|
|
memset(ws->bits, 0, bitset_size(nr_blocks)); |
|
|
|
ws->md.nr_bits = nr_blocks; |
|
r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root); |
|
if (r) { |
|
DMERR("%s: setup_on_disk_bitset failed", __func__); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static bool writeset_marked(struct writeset *ws, dm_block_t block) |
|
{ |
|
return test_bit(block, ws->bits); |
|
} |
|
|
|
static int writeset_marked_on_disk(struct dm_disk_bitset *info, |
|
struct writeset_metadata *m, dm_block_t block, |
|
bool *result) |
|
{ |
|
dm_block_t old = m->root; |
|
|
|
/* |
|
* The bitset was flushed when it was archived, so we know there'll |
|
* be no change to the root. |
|
*/ |
|
int r = dm_bitset_test_bit(info, m->root, block, &m->root, result); |
|
if (r) { |
|
DMERR("%s: dm_bitset_test_bit failed", __func__); |
|
return r; |
|
} |
|
|
|
BUG_ON(m->root != old); |
|
|
|
return r; |
|
} |
|
|
|
/* |
|
* Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. |
|
*/ |
|
static int writeset_test_and_set(struct dm_disk_bitset *info, |
|
struct writeset *ws, uint32_t block) |
|
{ |
|
int r; |
|
|
|
if (!test_bit(block, ws->bits)) { |
|
r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root); |
|
if (r) { |
|
/* FIXME: fail mode */ |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* On disk metadata layout |
|
*--------------------------------------------------------------*/ |
|
#define SPACE_MAP_ROOT_SIZE 128 |
|
#define UUID_LEN 16 |
|
|
|
struct writeset_disk { |
|
__le32 nr_bits; |
|
__le64 root; |
|
} __packed; |
|
|
|
struct superblock_disk { |
|
__le32 csum; |
|
__le32 flags; |
|
__le64 blocknr; |
|
|
|
__u8 uuid[UUID_LEN]; |
|
__le64 magic; |
|
__le32 version; |
|
|
|
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; |
|
|
|
__le32 data_block_size; |
|
__le32 metadata_block_size; |
|
__le32 nr_blocks; |
|
|
|
__le32 current_era; |
|
struct writeset_disk current_writeset; |
|
|
|
/* |
|
* Only these two fields are valid within the metadata snapshot. |
|
*/ |
|
__le64 writeset_tree_root; |
|
__le64 era_array_root; |
|
|
|
__le64 metadata_snap; |
|
} __packed; |
|
|
|
/*---------------------------------------------------------------- |
|
* Superblock validation |
|
*--------------------------------------------------------------*/ |
|
static void sb_prepare_for_write(struct dm_block_validator *v, |
|
struct dm_block *b, |
|
size_t sb_block_size) |
|
{ |
|
struct superblock_disk *disk = dm_block_data(b); |
|
|
|
disk->blocknr = cpu_to_le64(dm_block_location(b)); |
|
disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, |
|
sb_block_size - sizeof(__le32), |
|
SUPERBLOCK_CSUM_XOR)); |
|
} |
|
|
|
static int check_metadata_version(struct superblock_disk *disk) |
|
{ |
|
uint32_t metadata_version = le32_to_cpu(disk->version); |
|
if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { |
|
DMERR("Era metadata version %u found, but only versions between %u and %u supported.", |
|
metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int sb_check(struct dm_block_validator *v, |
|
struct dm_block *b, |
|
size_t sb_block_size) |
|
{ |
|
struct superblock_disk *disk = dm_block_data(b); |
|
__le32 csum_le; |
|
|
|
if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { |
|
DMERR("sb_check failed: blocknr %llu: wanted %llu", |
|
le64_to_cpu(disk->blocknr), |
|
(unsigned long long)dm_block_location(b)); |
|
return -ENOTBLK; |
|
} |
|
|
|
if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { |
|
DMERR("sb_check failed: magic %llu: wanted %llu", |
|
le64_to_cpu(disk->magic), |
|
(unsigned long long) SUPERBLOCK_MAGIC); |
|
return -EILSEQ; |
|
} |
|
|
|
csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, |
|
sb_block_size - sizeof(__le32), |
|
SUPERBLOCK_CSUM_XOR)); |
|
if (csum_le != disk->csum) { |
|
DMERR("sb_check failed: csum %u: wanted %u", |
|
le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); |
|
return -EILSEQ; |
|
} |
|
|
|
return check_metadata_version(disk); |
|
} |
|
|
|
static struct dm_block_validator sb_validator = { |
|
.name = "superblock", |
|
.prepare_for_write = sb_prepare_for_write, |
|
.check = sb_check |
|
}; |
|
|
|
/*---------------------------------------------------------------- |
|
* Low level metadata handling |
|
*--------------------------------------------------------------*/ |
|
#define DM_ERA_METADATA_BLOCK_SIZE 4096 |
|
#define ERA_MAX_CONCURRENT_LOCKS 5 |
|
|
|
struct era_metadata { |
|
struct block_device *bdev; |
|
struct dm_block_manager *bm; |
|
struct dm_space_map *sm; |
|
struct dm_transaction_manager *tm; |
|
|
|
dm_block_t block_size; |
|
uint32_t nr_blocks; |
|
|
|
uint32_t current_era; |
|
|
|
/* |
|
* We preallocate 2 writesets. When an era rolls over we |
|
* switch between them. This means the allocation is done at |
|
* preresume time, rather than on the io path. |
|
*/ |
|
struct writeset writesets[2]; |
|
struct writeset *current_writeset; |
|
|
|
dm_block_t writeset_tree_root; |
|
dm_block_t era_array_root; |
|
|
|
struct dm_disk_bitset bitset_info; |
|
struct dm_btree_info writeset_tree_info; |
|
struct dm_array_info era_array_info; |
|
|
|
dm_block_t metadata_snap; |
|
|
|
/* |
|
* A flag that is set whenever a writeset has been archived. |
|
*/ |
|
bool archived_writesets; |
|
|
|
/* |
|
* 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]; |
|
}; |
|
|
|
static int superblock_read_lock(struct era_metadata *md, |
|
struct dm_block **sblock) |
|
{ |
|
return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION, |
|
&sb_validator, sblock); |
|
} |
|
|
|
static int superblock_lock_zero(struct era_metadata *md, |
|
struct dm_block **sblock) |
|
{ |
|
return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION, |
|
&sb_validator, sblock); |
|
} |
|
|
|
static int superblock_lock(struct era_metadata *md, |
|
struct dm_block **sblock) |
|
{ |
|
return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION, |
|
&sb_validator, sblock); |
|
} |
|
|
|
/* FIXME: duplication with cache and thin */ |
|
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, 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 ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) |
|
{ |
|
disk->nr_bits = cpu_to_le32(core->nr_bits); |
|
disk->root = cpu_to_le64(core->root); |
|
} |
|
|
|
static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) |
|
{ |
|
core->nr_bits = le32_to_cpu(disk->nr_bits); |
|
core->root = le64_to_cpu(disk->root); |
|
} |
|
|
|
static void ws_inc(void *context, const void *value, unsigned count) |
|
{ |
|
struct era_metadata *md = context; |
|
struct writeset_disk ws_d; |
|
dm_block_t b; |
|
unsigned i; |
|
|
|
for (i = 0; i < count; i++) { |
|
memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); |
|
b = le64_to_cpu(ws_d.root); |
|
dm_tm_inc(md->tm, b); |
|
} |
|
} |
|
|
|
static void ws_dec(void *context, const void *value, unsigned count) |
|
{ |
|
struct era_metadata *md = context; |
|
struct writeset_disk ws_d; |
|
dm_block_t b; |
|
unsigned i; |
|
|
|
for (i = 0; i < count; i++) { |
|
memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); |
|
b = le64_to_cpu(ws_d.root); |
|
dm_bitset_del(&md->bitset_info, b); |
|
} |
|
} |
|
|
|
static int ws_eq(void *context, const void *value1, const void *value2) |
|
{ |
|
return !memcmp(value1, value2, sizeof(struct writeset_disk)); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static void setup_writeset_tree_info(struct era_metadata *md) |
|
{ |
|
struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; |
|
md->writeset_tree_info.tm = md->tm; |
|
md->writeset_tree_info.levels = 1; |
|
vt->context = md; |
|
vt->size = sizeof(struct writeset_disk); |
|
vt->inc = ws_inc; |
|
vt->dec = ws_dec; |
|
vt->equal = ws_eq; |
|
} |
|
|
|
static void setup_era_array_info(struct era_metadata *md) |
|
|
|
{ |
|
struct dm_btree_value_type vt; |
|
vt.context = NULL; |
|
vt.size = sizeof(__le32); |
|
vt.inc = NULL; |
|
vt.dec = NULL; |
|
vt.equal = NULL; |
|
|
|
dm_array_info_init(&md->era_array_info, md->tm, &vt); |
|
} |
|
|
|
static void setup_infos(struct era_metadata *md) |
|
{ |
|
dm_disk_bitset_init(md->tm, &md->bitset_info); |
|
setup_writeset_tree_info(md); |
|
setup_era_array_info(md); |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static int create_fresh_metadata(struct era_metadata *md) |
|
{ |
|
int r; |
|
|
|
r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION, |
|
&md->tm, &md->sm); |
|
if (r < 0) { |
|
DMERR("dm_tm_create_with_sm failed"); |
|
return r; |
|
} |
|
|
|
setup_infos(md); |
|
|
|
r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root); |
|
if (r) { |
|
DMERR("couldn't create new writeset tree"); |
|
goto bad; |
|
} |
|
|
|
r = dm_array_empty(&md->era_array_info, &md->era_array_root); |
|
if (r) { |
|
DMERR("couldn't create era array"); |
|
goto bad; |
|
} |
|
|
|
return 0; |
|
|
|
bad: |
|
dm_sm_destroy(md->sm); |
|
dm_tm_destroy(md->tm); |
|
|
|
return r; |
|
} |
|
|
|
static int save_sm_root(struct era_metadata *md) |
|
{ |
|
int r; |
|
size_t metadata_len; |
|
|
|
r = dm_sm_root_size(md->sm, &metadata_len); |
|
if (r < 0) |
|
return r; |
|
|
|
return dm_sm_copy_root(md->sm, &md->metadata_space_map_root, |
|
metadata_len); |
|
} |
|
|
|
static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) |
|
{ |
|
memcpy(&disk->metadata_space_map_root, |
|
&md->metadata_space_map_root, |
|
sizeof(md->metadata_space_map_root)); |
|
} |
|
|
|
/* |
|
* Writes a superblock, including the static fields that don't get updated |
|
* with every commit (possible optimisation here). 'md' should be fully |
|
* constructed when this is called. |
|
*/ |
|
static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) |
|
{ |
|
disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); |
|
disk->flags = cpu_to_le32(0ul); |
|
|
|
/* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ |
|
memset(disk->uuid, 0, sizeof(disk->uuid)); |
|
disk->version = cpu_to_le32(MAX_ERA_VERSION); |
|
|
|
copy_sm_root(md, disk); |
|
|
|
disk->data_block_size = cpu_to_le32(md->block_size); |
|
disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); |
|
disk->nr_blocks = cpu_to_le32(md->nr_blocks); |
|
disk->current_era = cpu_to_le32(md->current_era); |
|
|
|
ws_pack(&md->current_writeset->md, &disk->current_writeset); |
|
disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); |
|
disk->era_array_root = cpu_to_le64(md->era_array_root); |
|
disk->metadata_snap = cpu_to_le64(md->metadata_snap); |
|
} |
|
|
|
static int write_superblock(struct era_metadata *md) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
struct superblock_disk *disk; |
|
|
|
r = save_sm_root(md); |
|
if (r) { |
|
DMERR("%s: save_sm_root failed", __func__); |
|
return r; |
|
} |
|
|
|
r = superblock_lock_zero(md, &sblock); |
|
if (r) |
|
return r; |
|
|
|
disk = dm_block_data(sblock); |
|
prepare_superblock(md, disk); |
|
|
|
return dm_tm_commit(md->tm, sblock); |
|
} |
|
|
|
/* |
|
* Assumes block_size and the infos are set. |
|
*/ |
|
static int format_metadata(struct era_metadata *md) |
|
{ |
|
int r; |
|
|
|
r = create_fresh_metadata(md); |
|
if (r) |
|
return r; |
|
|
|
r = write_superblock(md); |
|
if (r) { |
|
dm_sm_destroy(md->sm); |
|
dm_tm_destroy(md->tm); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int open_metadata(struct era_metadata *md) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
struct superblock_disk *disk; |
|
|
|
r = superblock_read_lock(md, &sblock); |
|
if (r) { |
|
DMERR("couldn't read_lock superblock"); |
|
return r; |
|
} |
|
|
|
disk = dm_block_data(sblock); |
|
|
|
/* Verify the data block size hasn't changed */ |
|
if (le32_to_cpu(disk->data_block_size) != md->block_size) { |
|
DMERR("changing the data block size (from %u to %llu) is not supported", |
|
le32_to_cpu(disk->data_block_size), md->block_size); |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, |
|
disk->metadata_space_map_root, |
|
sizeof(disk->metadata_space_map_root), |
|
&md->tm, &md->sm); |
|
if (r) { |
|
DMERR("dm_tm_open_with_sm failed"); |
|
goto bad; |
|
} |
|
|
|
setup_infos(md); |
|
|
|
md->nr_blocks = le32_to_cpu(disk->nr_blocks); |
|
md->current_era = le32_to_cpu(disk->current_era); |
|
|
|
ws_unpack(&disk->current_writeset, &md->current_writeset->md); |
|
md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); |
|
md->era_array_root = le64_to_cpu(disk->era_array_root); |
|
md->metadata_snap = le64_to_cpu(disk->metadata_snap); |
|
md->archived_writesets = true; |
|
|
|
dm_bm_unlock(sblock); |
|
|
|
return 0; |
|
|
|
bad: |
|
dm_bm_unlock(sblock); |
|
return r; |
|
} |
|
|
|
static int open_or_format_metadata(struct era_metadata *md, |
|
bool may_format) |
|
{ |
|
int r; |
|
bool unformatted = false; |
|
|
|
r = superblock_all_zeroes(md->bm, &unformatted); |
|
if (r) |
|
return r; |
|
|
|
if (unformatted) |
|
return may_format ? format_metadata(md) : -EPERM; |
|
|
|
return open_metadata(md); |
|
} |
|
|
|
static int create_persistent_data_objects(struct era_metadata *md, |
|
bool may_format) |
|
{ |
|
int r; |
|
|
|
md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE, |
|
ERA_MAX_CONCURRENT_LOCKS); |
|
if (IS_ERR(md->bm)) { |
|
DMERR("could not create block manager"); |
|
return PTR_ERR(md->bm); |
|
} |
|
|
|
r = open_or_format_metadata(md, may_format); |
|
if (r) |
|
dm_block_manager_destroy(md->bm); |
|
|
|
return r; |
|
} |
|
|
|
static void destroy_persistent_data_objects(struct era_metadata *md) |
|
{ |
|
dm_sm_destroy(md->sm); |
|
dm_tm_destroy(md->tm); |
|
dm_block_manager_destroy(md->bm); |
|
} |
|
|
|
/* |
|
* This waits until all era_map threads have picked up the new filter. |
|
*/ |
|
static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) |
|
{ |
|
rcu_assign_pointer(md->current_writeset, new_writeset); |
|
synchronize_rcu(); |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Writesets get 'digested' into the main era array. |
|
* |
|
* We're using a coroutine here so the worker thread can do the digestion, |
|
* thus avoiding synchronisation of the metadata. Digesting a whole |
|
* writeset in one go would cause too much latency. |
|
*--------------------------------------------------------------*/ |
|
struct digest { |
|
uint32_t era; |
|
unsigned nr_bits, current_bit; |
|
struct writeset_metadata writeset; |
|
__le32 value; |
|
struct dm_disk_bitset info; |
|
|
|
int (*step)(struct era_metadata *, struct digest *); |
|
}; |
|
|
|
static int metadata_digest_lookup_writeset(struct era_metadata *md, |
|
struct digest *d); |
|
|
|
static int metadata_digest_remove_writeset(struct era_metadata *md, |
|
struct digest *d) |
|
{ |
|
int r; |
|
uint64_t key = d->era; |
|
|
|
r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root, |
|
&key, &md->writeset_tree_root); |
|
if (r) { |
|
DMERR("%s: dm_btree_remove failed", __func__); |
|
return r; |
|
} |
|
|
|
d->step = metadata_digest_lookup_writeset; |
|
return 0; |
|
} |
|
|
|
#define INSERTS_PER_STEP 100 |
|
|
|
static int metadata_digest_transcribe_writeset(struct era_metadata *md, |
|
struct digest *d) |
|
{ |
|
int r; |
|
bool marked; |
|
unsigned b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); |
|
|
|
for (b = d->current_bit; b < e; b++) { |
|
r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked); |
|
if (r) { |
|
DMERR("%s: writeset_marked_on_disk failed", __func__); |
|
return r; |
|
} |
|
|
|
if (!marked) |
|
continue; |
|
|
|
__dm_bless_for_disk(&d->value); |
|
r = dm_array_set_value(&md->era_array_info, md->era_array_root, |
|
b, &d->value, &md->era_array_root); |
|
if (r) { |
|
DMERR("%s: dm_array_set_value failed", __func__); |
|
return r; |
|
} |
|
} |
|
|
|
if (b == d->nr_bits) |
|
d->step = metadata_digest_remove_writeset; |
|
else |
|
d->current_bit = b; |
|
|
|
return 0; |
|
} |
|
|
|
static int metadata_digest_lookup_writeset(struct era_metadata *md, |
|
struct digest *d) |
|
{ |
|
int r; |
|
uint64_t key; |
|
struct writeset_disk disk; |
|
|
|
r = dm_btree_find_lowest_key(&md->writeset_tree_info, |
|
md->writeset_tree_root, &key); |
|
if (r < 0) |
|
return r; |
|
|
|
d->era = key; |
|
|
|
r = dm_btree_lookup(&md->writeset_tree_info, |
|
md->writeset_tree_root, &key, &disk); |
|
if (r) { |
|
if (r == -ENODATA) { |
|
d->step = NULL; |
|
return 0; |
|
} |
|
|
|
DMERR("%s: dm_btree_lookup failed", __func__); |
|
return r; |
|
} |
|
|
|
ws_unpack(&disk, &d->writeset); |
|
d->value = cpu_to_le32(key); |
|
|
|
/* |
|
* We initialise another bitset info to avoid any caching side effects |
|
* with the previous one. |
|
*/ |
|
dm_disk_bitset_init(md->tm, &d->info); |
|
|
|
d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); |
|
d->current_bit = 0; |
|
d->step = metadata_digest_transcribe_writeset; |
|
|
|
return 0; |
|
} |
|
|
|
static int metadata_digest_start(struct era_metadata *md, struct digest *d) |
|
{ |
|
if (d->step) |
|
return 0; |
|
|
|
memset(d, 0, sizeof(*d)); |
|
d->step = metadata_digest_lookup_writeset; |
|
|
|
return 0; |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* High level metadata interface. Target methods should use these, and not |
|
* the lower level ones. |
|
*--------------------------------------------------------------*/ |
|
static struct era_metadata *metadata_open(struct block_device *bdev, |
|
sector_t block_size, |
|
bool may_format) |
|
{ |
|
int r; |
|
struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL); |
|
|
|
if (!md) |
|
return NULL; |
|
|
|
md->bdev = bdev; |
|
md->block_size = block_size; |
|
|
|
md->writesets[0].md.root = INVALID_WRITESET_ROOT; |
|
md->writesets[1].md.root = INVALID_WRITESET_ROOT; |
|
md->current_writeset = &md->writesets[0]; |
|
|
|
r = create_persistent_data_objects(md, may_format); |
|
if (r) { |
|
kfree(md); |
|
return ERR_PTR(r); |
|
} |
|
|
|
return md; |
|
} |
|
|
|
static void metadata_close(struct era_metadata *md) |
|
{ |
|
writeset_free(&md->writesets[0]); |
|
writeset_free(&md->writesets[1]); |
|
destroy_persistent_data_objects(md); |
|
kfree(md); |
|
} |
|
|
|
static bool valid_nr_blocks(dm_block_t n) |
|
{ |
|
/* |
|
* dm_bitset restricts us to 2^32. test_bit & co. restrict us |
|
* further to 2^31 - 1 |
|
*/ |
|
return n < (1ull << 31); |
|
} |
|
|
|
static int metadata_resize(struct era_metadata *md, void *arg) |
|
{ |
|
int r; |
|
dm_block_t *new_size = arg; |
|
__le32 value; |
|
|
|
if (!valid_nr_blocks(*new_size)) { |
|
DMERR("Invalid number of origin blocks %llu", |
|
(unsigned long long) *new_size); |
|
return -EINVAL; |
|
} |
|
|
|
writeset_free(&md->writesets[0]); |
|
writeset_free(&md->writesets[1]); |
|
|
|
r = writeset_alloc(&md->writesets[0], *new_size); |
|
if (r) { |
|
DMERR("%s: writeset_alloc failed for writeset 0", __func__); |
|
return r; |
|
} |
|
|
|
r = writeset_alloc(&md->writesets[1], *new_size); |
|
if (r) { |
|
DMERR("%s: writeset_alloc failed for writeset 1", __func__); |
|
writeset_free(&md->writesets[0]); |
|
return r; |
|
} |
|
|
|
value = cpu_to_le32(0u); |
|
__dm_bless_for_disk(&value); |
|
r = dm_array_resize(&md->era_array_info, md->era_array_root, |
|
md->nr_blocks, *new_size, |
|
&value, &md->era_array_root); |
|
if (r) { |
|
DMERR("%s: dm_array_resize failed", __func__); |
|
writeset_free(&md->writesets[0]); |
|
writeset_free(&md->writesets[1]); |
|
return r; |
|
} |
|
|
|
md->nr_blocks = *new_size; |
|
return 0; |
|
} |
|
|
|
static int metadata_era_archive(struct era_metadata *md) |
|
{ |
|
int r; |
|
uint64_t keys[1]; |
|
struct writeset_disk value; |
|
|
|
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, |
|
&md->current_writeset->md.root); |
|
if (r) { |
|
DMERR("%s: dm_bitset_flush failed", __func__); |
|
return r; |
|
} |
|
|
|
ws_pack(&md->current_writeset->md, &value); |
|
|
|
keys[0] = md->current_era; |
|
__dm_bless_for_disk(&value); |
|
r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, |
|
keys, &value, &md->writeset_tree_root); |
|
if (r) { |
|
DMERR("%s: couldn't insert writeset into btree", __func__); |
|
/* FIXME: fail mode */ |
|
return r; |
|
} |
|
|
|
md->current_writeset->md.root = INVALID_WRITESET_ROOT; |
|
md->archived_writesets = true; |
|
|
|
return 0; |
|
} |
|
|
|
static struct writeset *next_writeset(struct era_metadata *md) |
|
{ |
|
return (md->current_writeset == &md->writesets[0]) ? |
|
&md->writesets[1] : &md->writesets[0]; |
|
} |
|
|
|
static int metadata_new_era(struct era_metadata *md) |
|
{ |
|
int r; |
|
struct writeset *new_writeset = next_writeset(md); |
|
|
|
r = writeset_init(&md->bitset_info, new_writeset, md->nr_blocks); |
|
if (r) { |
|
DMERR("%s: writeset_init failed", __func__); |
|
return r; |
|
} |
|
|
|
swap_writeset(md, new_writeset); |
|
md->current_era++; |
|
|
|
return 0; |
|
} |
|
|
|
static int metadata_era_rollover(struct era_metadata *md) |
|
{ |
|
int r; |
|
|
|
if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { |
|
r = metadata_era_archive(md); |
|
if (r) { |
|
DMERR("%s: metadata_archive_era failed", __func__); |
|
/* FIXME: fail mode? */ |
|
return r; |
|
} |
|
} |
|
|
|
r = metadata_new_era(md); |
|
if (r) { |
|
DMERR("%s: new era failed", __func__); |
|
/* FIXME: fail mode */ |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) |
|
{ |
|
bool r; |
|
struct writeset *ws; |
|
|
|
rcu_read_lock(); |
|
ws = rcu_dereference(md->current_writeset); |
|
r = writeset_marked(ws, block); |
|
rcu_read_unlock(); |
|
|
|
return r; |
|
} |
|
|
|
static int metadata_commit(struct era_metadata *md) |
|
{ |
|
int r; |
|
struct dm_block *sblock; |
|
|
|
if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { |
|
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, |
|
&md->current_writeset->md.root); |
|
if (r) { |
|
DMERR("%s: bitset flush failed", __func__); |
|
return r; |
|
} |
|
} |
|
|
|
r = dm_tm_pre_commit(md->tm); |
|
if (r) { |
|
DMERR("%s: pre commit failed", __func__); |
|
return r; |
|
} |
|
|
|
r = save_sm_root(md); |
|
if (r) { |
|
DMERR("%s: save_sm_root failed", __func__); |
|
return r; |
|
} |
|
|
|
r = superblock_lock(md, &sblock); |
|
if (r) { |
|
DMERR("%s: superblock lock failed", __func__); |
|
return r; |
|
} |
|
|
|
prepare_superblock(md, dm_block_data(sblock)); |
|
|
|
return dm_tm_commit(md->tm, sblock); |
|
} |
|
|
|
static int metadata_checkpoint(struct era_metadata *md) |
|
{ |
|
/* |
|
* For now we just rollover, but later I want to put a check in to |
|
* avoid this if the filter is still pretty fresh. |
|
*/ |
|
return metadata_era_rollover(md); |
|
} |
|
|
|
/* |
|
* Metadata snapshots allow userland to access era data. |
|
*/ |
|
static int metadata_take_snap(struct era_metadata *md) |
|
{ |
|
int r, inc; |
|
struct dm_block *clone; |
|
|
|
if (md->metadata_snap != SUPERBLOCK_LOCATION) { |
|
DMERR("%s: metadata snapshot already exists", __func__); |
|
return -EINVAL; |
|
} |
|
|
|
r = metadata_era_rollover(md); |
|
if (r) { |
|
DMERR("%s: era rollover failed", __func__); |
|
return r; |
|
} |
|
|
|
r = metadata_commit(md); |
|
if (r) { |
|
DMERR("%s: pre commit failed", __func__); |
|
return r; |
|
} |
|
|
|
r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); |
|
if (r) { |
|
DMERR("%s: couldn't increment superblock", __func__); |
|
return r; |
|
} |
|
|
|
r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, |
|
&sb_validator, &clone, &inc); |
|
if (r) { |
|
DMERR("%s: couldn't shadow superblock", __func__); |
|
dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); |
|
return r; |
|
} |
|
BUG_ON(!inc); |
|
|
|
r = dm_sm_inc_block(md->sm, md->writeset_tree_root); |
|
if (r) { |
|
DMERR("%s: couldn't inc writeset tree root", __func__); |
|
dm_tm_unlock(md->tm, clone); |
|
return r; |
|
} |
|
|
|
r = dm_sm_inc_block(md->sm, md->era_array_root); |
|
if (r) { |
|
DMERR("%s: couldn't inc era tree root", __func__); |
|
dm_sm_dec_block(md->sm, md->writeset_tree_root); |
|
dm_tm_unlock(md->tm, clone); |
|
return r; |
|
} |
|
|
|
md->metadata_snap = dm_block_location(clone); |
|
|
|
dm_tm_unlock(md->tm, clone); |
|
|
|
return 0; |
|
} |
|
|
|
static int metadata_drop_snap(struct era_metadata *md) |
|
{ |
|
int r; |
|
dm_block_t location; |
|
struct dm_block *clone; |
|
struct superblock_disk *disk; |
|
|
|
if (md->metadata_snap == SUPERBLOCK_LOCATION) { |
|
DMERR("%s: no snap to drop", __func__); |
|
return -EINVAL; |
|
} |
|
|
|
r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); |
|
if (r) { |
|
DMERR("%s: couldn't read lock superblock clone", __func__); |
|
return r; |
|
} |
|
|
|
/* |
|
* Whatever happens now we'll commit with no record of the metadata |
|
* snap. |
|
*/ |
|
md->metadata_snap = SUPERBLOCK_LOCATION; |
|
|
|
disk = dm_block_data(clone); |
|
r = dm_btree_del(&md->writeset_tree_info, |
|
le64_to_cpu(disk->writeset_tree_root)); |
|
if (r) { |
|
DMERR("%s: error deleting writeset tree clone", __func__); |
|
dm_tm_unlock(md->tm, clone); |
|
return r; |
|
} |
|
|
|
r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); |
|
if (r) { |
|
DMERR("%s: error deleting era array clone", __func__); |
|
dm_tm_unlock(md->tm, clone); |
|
return r; |
|
} |
|
|
|
location = dm_block_location(clone); |
|
dm_tm_unlock(md->tm, clone); |
|
|
|
return dm_sm_dec_block(md->sm, location); |
|
} |
|
|
|
struct metadata_stats { |
|
dm_block_t used; |
|
dm_block_t total; |
|
dm_block_t snap; |
|
uint32_t era; |
|
}; |
|
|
|
static int metadata_get_stats(struct era_metadata *md, void *ptr) |
|
{ |
|
int r; |
|
struct metadata_stats *s = ptr; |
|
dm_block_t nr_free, nr_total; |
|
|
|
r = dm_sm_get_nr_free(md->sm, &nr_free); |
|
if (r) { |
|
DMERR("dm_sm_get_nr_free returned %d", r); |
|
return r; |
|
} |
|
|
|
r = dm_sm_get_nr_blocks(md->sm, &nr_total); |
|
if (r) { |
|
DMERR("dm_pool_get_metadata_dev_size returned %d", r); |
|
return r; |
|
} |
|
|
|
s->used = nr_total - nr_free; |
|
s->total = nr_total; |
|
s->snap = md->metadata_snap; |
|
s->era = md->current_era; |
|
|
|
return 0; |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
struct era { |
|
struct dm_target *ti; |
|
|
|
struct dm_dev *metadata_dev; |
|
struct dm_dev *origin_dev; |
|
|
|
dm_block_t nr_blocks; |
|
uint32_t sectors_per_block; |
|
int sectors_per_block_shift; |
|
struct era_metadata *md; |
|
|
|
struct workqueue_struct *wq; |
|
struct work_struct worker; |
|
|
|
spinlock_t deferred_lock; |
|
struct bio_list deferred_bios; |
|
|
|
spinlock_t rpc_lock; |
|
struct list_head rpc_calls; |
|
|
|
struct digest digest; |
|
atomic_t suspended; |
|
}; |
|
|
|
struct rpc { |
|
struct list_head list; |
|
|
|
int (*fn0)(struct era_metadata *); |
|
int (*fn1)(struct era_metadata *, void *); |
|
void *arg; |
|
int result; |
|
|
|
struct completion complete; |
|
}; |
|
|
|
/*---------------------------------------------------------------- |
|
* Remapping. |
|
*---------------------------------------------------------------*/ |
|
static bool block_size_is_power_of_two(struct era *era) |
|
{ |
|
return era->sectors_per_block_shift >= 0; |
|
} |
|
|
|
static dm_block_t get_block(struct era *era, struct bio *bio) |
|
{ |
|
sector_t block_nr = bio->bi_iter.bi_sector; |
|
|
|
if (!block_size_is_power_of_two(era)) |
|
(void) sector_div(block_nr, era->sectors_per_block); |
|
else |
|
block_nr >>= era->sectors_per_block_shift; |
|
|
|
return block_nr; |
|
} |
|
|
|
static void remap_to_origin(struct era *era, struct bio *bio) |
|
{ |
|
bio_set_dev(bio, era->origin_dev->bdev); |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Worker thread |
|
*--------------------------------------------------------------*/ |
|
static void wake_worker(struct era *era) |
|
{ |
|
if (!atomic_read(&era->suspended)) |
|
queue_work(era->wq, &era->worker); |
|
} |
|
|
|
static void process_old_eras(struct era *era) |
|
{ |
|
int r; |
|
|
|
if (!era->digest.step) |
|
return; |
|
|
|
r = era->digest.step(era->md, &era->digest); |
|
if (r < 0) { |
|
DMERR("%s: digest step failed, stopping digestion", __func__); |
|
era->digest.step = NULL; |
|
|
|
} else if (era->digest.step) |
|
wake_worker(era); |
|
} |
|
|
|
static void process_deferred_bios(struct era *era) |
|
{ |
|
int r; |
|
struct bio_list deferred_bios, marked_bios; |
|
struct bio *bio; |
|
struct blk_plug plug; |
|
bool commit_needed = false; |
|
bool failed = false; |
|
struct writeset *ws = era->md->current_writeset; |
|
|
|
bio_list_init(&deferred_bios); |
|
bio_list_init(&marked_bios); |
|
|
|
spin_lock(&era->deferred_lock); |
|
bio_list_merge(&deferred_bios, &era->deferred_bios); |
|
bio_list_init(&era->deferred_bios); |
|
spin_unlock(&era->deferred_lock); |
|
|
|
if (bio_list_empty(&deferred_bios)) |
|
return; |
|
|
|
while ((bio = bio_list_pop(&deferred_bios))) { |
|
r = writeset_test_and_set(&era->md->bitset_info, ws, |
|
get_block(era, bio)); |
|
if (r < 0) { |
|
/* |
|
* This is bad news, we need to rollback. |
|
* FIXME: finish. |
|
*/ |
|
failed = true; |
|
} else if (r == 0) |
|
commit_needed = true; |
|
|
|
bio_list_add(&marked_bios, bio); |
|
} |
|
|
|
if (commit_needed) { |
|
r = metadata_commit(era->md); |
|
if (r) |
|
failed = true; |
|
} |
|
|
|
if (failed) |
|
while ((bio = bio_list_pop(&marked_bios))) |
|
bio_io_error(bio); |
|
else { |
|
blk_start_plug(&plug); |
|
while ((bio = bio_list_pop(&marked_bios))) { |
|
/* |
|
* Only update the in-core writeset if the on-disk one |
|
* was updated too. |
|
*/ |
|
if (commit_needed) |
|
set_bit(get_block(era, bio), ws->bits); |
|
submit_bio_noacct(bio); |
|
} |
|
blk_finish_plug(&plug); |
|
} |
|
} |
|
|
|
static void process_rpc_calls(struct era *era) |
|
{ |
|
int r; |
|
bool need_commit = false; |
|
struct list_head calls; |
|
struct rpc *rpc, *tmp; |
|
|
|
INIT_LIST_HEAD(&calls); |
|
spin_lock(&era->rpc_lock); |
|
list_splice_init(&era->rpc_calls, &calls); |
|
spin_unlock(&era->rpc_lock); |
|
|
|
list_for_each_entry_safe(rpc, tmp, &calls, list) { |
|
rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); |
|
need_commit = true; |
|
} |
|
|
|
if (need_commit) { |
|
r = metadata_commit(era->md); |
|
if (r) |
|
list_for_each_entry_safe(rpc, tmp, &calls, list) |
|
rpc->result = r; |
|
} |
|
|
|
list_for_each_entry_safe(rpc, tmp, &calls, list) |
|
complete(&rpc->complete); |
|
} |
|
|
|
static void kick_off_digest(struct era *era) |
|
{ |
|
if (era->md->archived_writesets) { |
|
era->md->archived_writesets = false; |
|
metadata_digest_start(era->md, &era->digest); |
|
} |
|
} |
|
|
|
static void do_work(struct work_struct *ws) |
|
{ |
|
struct era *era = container_of(ws, struct era, worker); |
|
|
|
kick_off_digest(era); |
|
process_old_eras(era); |
|
process_deferred_bios(era); |
|
process_rpc_calls(era); |
|
} |
|
|
|
static void defer_bio(struct era *era, struct bio *bio) |
|
{ |
|
spin_lock(&era->deferred_lock); |
|
bio_list_add(&era->deferred_bios, bio); |
|
spin_unlock(&era->deferred_lock); |
|
|
|
wake_worker(era); |
|
} |
|
|
|
/* |
|
* Make an rpc call to the worker to change the metadata. |
|
*/ |
|
static int perform_rpc(struct era *era, struct rpc *rpc) |
|
{ |
|
rpc->result = 0; |
|
init_completion(&rpc->complete); |
|
|
|
spin_lock(&era->rpc_lock); |
|
list_add(&rpc->list, &era->rpc_calls); |
|
spin_unlock(&era->rpc_lock); |
|
|
|
wake_worker(era); |
|
wait_for_completion(&rpc->complete); |
|
|
|
return rpc->result; |
|
} |
|
|
|
static int in_worker0(struct era *era, int (*fn)(struct era_metadata *)) |
|
{ |
|
struct rpc rpc; |
|
rpc.fn0 = fn; |
|
rpc.fn1 = NULL; |
|
|
|
return perform_rpc(era, &rpc); |
|
} |
|
|
|
static int in_worker1(struct era *era, |
|
int (*fn)(struct era_metadata *, void *), void *arg) |
|
{ |
|
struct rpc rpc; |
|
rpc.fn0 = NULL; |
|
rpc.fn1 = fn; |
|
rpc.arg = arg; |
|
|
|
return perform_rpc(era, &rpc); |
|
} |
|
|
|
static void start_worker(struct era *era) |
|
{ |
|
atomic_set(&era->suspended, 0); |
|
} |
|
|
|
static void stop_worker(struct era *era) |
|
{ |
|
atomic_set(&era->suspended, 1); |
|
flush_workqueue(era->wq); |
|
} |
|
|
|
/*---------------------------------------------------------------- |
|
* Target methods |
|
*--------------------------------------------------------------*/ |
|
static void era_destroy(struct era *era) |
|
{ |
|
if (era->md) |
|
metadata_close(era->md); |
|
|
|
if (era->wq) |
|
destroy_workqueue(era->wq); |
|
|
|
if (era->origin_dev) |
|
dm_put_device(era->ti, era->origin_dev); |
|
|
|
if (era->metadata_dev) |
|
dm_put_device(era->ti, era->metadata_dev); |
|
|
|
kfree(era); |
|
} |
|
|
|
static dm_block_t calc_nr_blocks(struct era *era) |
|
{ |
|
return dm_sector_div_up(era->ti->len, era->sectors_per_block); |
|
} |
|
|
|
static bool valid_block_size(dm_block_t block_size) |
|
{ |
|
bool greater_than_zero = block_size > 0; |
|
bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; |
|
|
|
return greater_than_zero && multiple_of_min_block_size; |
|
} |
|
|
|
/* |
|
* <metadata dev> <data dev> <data block size (sectors)> |
|
*/ |
|
static int era_ctr(struct dm_target *ti, unsigned argc, char **argv) |
|
{ |
|
int r; |
|
char dummy; |
|
struct era *era; |
|
struct era_metadata *md; |
|
|
|
if (argc != 3) { |
|
ti->error = "Invalid argument count"; |
|
return -EINVAL; |
|
} |
|
|
|
era = kzalloc(sizeof(*era), GFP_KERNEL); |
|
if (!era) { |
|
ti->error = "Error allocating era structure"; |
|
return -ENOMEM; |
|
} |
|
|
|
era->ti = ti; |
|
|
|
r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &era->metadata_dev); |
|
if (r) { |
|
ti->error = "Error opening metadata device"; |
|
era_destroy(era); |
|
return -EINVAL; |
|
} |
|
|
|
r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &era->origin_dev); |
|
if (r) { |
|
ti->error = "Error opening data device"; |
|
era_destroy(era); |
|
return -EINVAL; |
|
} |
|
|
|
r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); |
|
if (r != 1) { |
|
ti->error = "Error parsing block size"; |
|
era_destroy(era); |
|
return -EINVAL; |
|
} |
|
|
|
r = dm_set_target_max_io_len(ti, era->sectors_per_block); |
|
if (r) { |
|
ti->error = "could not set max io len"; |
|
era_destroy(era); |
|
return -EINVAL; |
|
} |
|
|
|
if (!valid_block_size(era->sectors_per_block)) { |
|
ti->error = "Invalid block size"; |
|
era_destroy(era); |
|
return -EINVAL; |
|
} |
|
if (era->sectors_per_block & (era->sectors_per_block - 1)) |
|
era->sectors_per_block_shift = -1; |
|
else |
|
era->sectors_per_block_shift = __ffs(era->sectors_per_block); |
|
|
|
md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); |
|
if (IS_ERR(md)) { |
|
ti->error = "Error reading metadata"; |
|
era_destroy(era); |
|
return PTR_ERR(md); |
|
} |
|
era->md = md; |
|
|
|
era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); |
|
if (!era->wq) { |
|
ti->error = "could not create workqueue for metadata object"; |
|
era_destroy(era); |
|
return -ENOMEM; |
|
} |
|
INIT_WORK(&era->worker, do_work); |
|
|
|
spin_lock_init(&era->deferred_lock); |
|
bio_list_init(&era->deferred_bios); |
|
|
|
spin_lock_init(&era->rpc_lock); |
|
INIT_LIST_HEAD(&era->rpc_calls); |
|
|
|
ti->private = era; |
|
ti->num_flush_bios = 1; |
|
ti->flush_supported = true; |
|
|
|
ti->num_discard_bios = 1; |
|
|
|
return 0; |
|
} |
|
|
|
static void era_dtr(struct dm_target *ti) |
|
{ |
|
era_destroy(ti->private); |
|
} |
|
|
|
static int era_map(struct dm_target *ti, struct bio *bio) |
|
{ |
|
struct era *era = ti->private; |
|
dm_block_t block = get_block(era, bio); |
|
|
|
/* |
|
* All bios get remapped to the origin device. We do this now, but |
|
* it may not get issued until later. Depending on whether the |
|
* block is marked in this era. |
|
*/ |
|
remap_to_origin(era, bio); |
|
|
|
/* |
|
* REQ_PREFLUSH bios carry no data, so we're not interested in them. |
|
*/ |
|
if (!(bio->bi_opf & REQ_PREFLUSH) && |
|
(bio_data_dir(bio) == WRITE) && |
|
!metadata_current_marked(era->md, block)) { |
|
defer_bio(era, bio); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
return DM_MAPIO_REMAPPED; |
|
} |
|
|
|
static void era_postsuspend(struct dm_target *ti) |
|
{ |
|
int r; |
|
struct era *era = ti->private; |
|
|
|
r = in_worker0(era, metadata_era_archive); |
|
if (r) { |
|
DMERR("%s: couldn't archive current era", __func__); |
|
/* FIXME: fail mode */ |
|
} |
|
|
|
stop_worker(era); |
|
} |
|
|
|
static int era_preresume(struct dm_target *ti) |
|
{ |
|
int r; |
|
struct era *era = ti->private; |
|
dm_block_t new_size = calc_nr_blocks(era); |
|
|
|
if (era->nr_blocks != new_size) { |
|
r = metadata_resize(era->md, &new_size); |
|
if (r) { |
|
DMERR("%s: metadata_resize failed", __func__); |
|
return r; |
|
} |
|
|
|
r = metadata_commit(era->md); |
|
if (r) { |
|
DMERR("%s: metadata_commit failed", __func__); |
|
return r; |
|
} |
|
|
|
era->nr_blocks = new_size; |
|
} |
|
|
|
start_worker(era); |
|
|
|
r = in_worker0(era, metadata_era_rollover); |
|
if (r) { |
|
DMERR("%s: metadata_era_rollover failed", __func__); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Status format: |
|
* |
|
* <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
|
* <current era> <held metadata root | '-'> |
|
*/ |
|
static void era_status(struct dm_target *ti, status_type_t type, |
|
unsigned status_flags, char *result, unsigned maxlen) |
|
{ |
|
int r; |
|
struct era *era = ti->private; |
|
ssize_t sz = 0; |
|
struct metadata_stats stats; |
|
char buf[BDEVNAME_SIZE]; |
|
|
|
switch (type) { |
|
case STATUSTYPE_INFO: |
|
r = in_worker1(era, metadata_get_stats, &stats); |
|
if (r) |
|
goto err; |
|
|
|
DMEMIT("%u %llu/%llu %u", |
|
(unsigned) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), |
|
(unsigned long long) stats.used, |
|
(unsigned long long) stats.total, |
|
(unsigned) stats.era); |
|
|
|
if (stats.snap != SUPERBLOCK_LOCATION) |
|
DMEMIT(" %llu", stats.snap); |
|
else |
|
DMEMIT(" -"); |
|
break; |
|
|
|
case STATUSTYPE_TABLE: |
|
format_dev_t(buf, era->metadata_dev->bdev->bd_dev); |
|
DMEMIT("%s ", buf); |
|
format_dev_t(buf, era->origin_dev->bdev->bd_dev); |
|
DMEMIT("%s %u", buf, era->sectors_per_block); |
|
break; |
|
|
|
case STATUSTYPE_IMA: |
|
*result = '\0'; |
|
break; |
|
} |
|
|
|
return; |
|
|
|
err: |
|
DMEMIT("Error"); |
|
} |
|
|
|
static int era_message(struct dm_target *ti, unsigned argc, char **argv, |
|
char *result, unsigned maxlen) |
|
{ |
|
struct era *era = ti->private; |
|
|
|
if (argc != 1) { |
|
DMERR("incorrect number of message arguments"); |
|
return -EINVAL; |
|
} |
|
|
|
if (!strcasecmp(argv[0], "checkpoint")) |
|
return in_worker0(era, metadata_checkpoint); |
|
|
|
if (!strcasecmp(argv[0], "take_metadata_snap")) |
|
return in_worker0(era, metadata_take_snap); |
|
|
|
if (!strcasecmp(argv[0], "drop_metadata_snap")) |
|
return in_worker0(era, metadata_drop_snap); |
|
|
|
DMERR("unsupported message '%s'", argv[0]); |
|
return -EINVAL; |
|
} |
|
|
|
static sector_t get_dev_size(struct dm_dev *dev) |
|
{ |
|
return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; |
|
} |
|
|
|
static int era_iterate_devices(struct dm_target *ti, |
|
iterate_devices_callout_fn fn, void *data) |
|
{ |
|
struct era *era = ti->private; |
|
return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); |
|
} |
|
|
|
static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) |
|
{ |
|
struct era *era = ti->private; |
|
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
|
|
|
/* |
|
* If the system-determined stacked limits are compatible with the |
|
* era device's blocksize (io_opt is a factor) do not override them. |
|
*/ |
|
if (io_opt_sectors < era->sectors_per_block || |
|
do_div(io_opt_sectors, era->sectors_per_block)) { |
|
blk_limits_io_min(limits, 0); |
|
blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT); |
|
} |
|
} |
|
|
|
/*----------------------------------------------------------------*/ |
|
|
|
static struct target_type era_target = { |
|
.name = "era", |
|
.version = {1, 0, 0}, |
|
.module = THIS_MODULE, |
|
.ctr = era_ctr, |
|
.dtr = era_dtr, |
|
.map = era_map, |
|
.postsuspend = era_postsuspend, |
|
.preresume = era_preresume, |
|
.status = era_status, |
|
.message = era_message, |
|
.iterate_devices = era_iterate_devices, |
|
.io_hints = era_io_hints |
|
}; |
|
|
|
static int __init dm_era_init(void) |
|
{ |
|
int r; |
|
|
|
r = dm_register_target(&era_target); |
|
if (r) { |
|
DMERR("era target registration failed: %d", r); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void __exit dm_era_exit(void) |
|
{ |
|
dm_unregister_target(&era_target); |
|
} |
|
|
|
module_init(dm_era_init); |
|
module_exit(dm_era_exit); |
|
|
|
MODULE_DESCRIPTION(DM_NAME " era target"); |
|
MODULE_AUTHOR("Joe Thornber <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|