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linux-zen-desktop/drivers/md/dm-thin-metadata.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011-2012 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-thin-metadata.h"
#include "persistent-data/dm-btree.h"
#include "persistent-data/dm-space-map.h"
#include "persistent-data/dm-space-map-disk.h"
#include "persistent-data/dm-transaction-manager.h"
#include <linux/list.h>
#include <linux/device-mapper.h>
#include <linux/workqueue.h>
/*
*--------------------------------------------------------------------------
* As far as the metadata goes, there is:
*
* - A superblock in block zero, taking up fewer than 512 bytes for
* atomic writes.
*
* - A space map managing the metadata blocks.
*
* - A space map managing the data blocks.
*
* - A btree mapping our internal thin dev ids onto struct disk_device_details.
*
* - A hierarchical btree, with 2 levels which effectively maps (thin
* dev id, virtual block) -> block_time. Block time is a 64-bit
* field holding the time in the low 24 bits, and block in the top 40
* bits.
*
* BTrees consist solely of btree_nodes, that fill a block. Some are
* internal nodes, as such their values are a __le64 pointing to other
* nodes. Leaf nodes can store data of any reasonable size (ie. much
* smaller than the block size). The nodes consist of the header,
* followed by an array of keys, followed by an array of values. We have
* to binary search on the keys so they're all held together to help the
* cpu cache.
*
* Space maps have 2 btrees:
*
* - One maps a uint64_t onto a struct index_entry. Which points to a
* bitmap block, and has some details about how many free entries there
* are etc.
*
* - The bitmap blocks have a header (for the checksum). Then the rest
* of the block is pairs of bits. With the meaning being:
*
* 0 - ref count is 0
* 1 - ref count is 1
* 2 - ref count is 2
* 3 - ref count is higher than 2
*
* - If the count is higher than 2 then the ref count is entered in a
* second btree that directly maps the block_address to a uint32_t ref
* count.
*
* The space map metadata variant doesn't have a bitmaps btree. Instead
* it has one single blocks worth of index_entries. This avoids
* recursive issues with the bitmap btree needing to allocate space in
* order to insert. With a small data block size such as 64k the
* metadata support data devices that are hundreds of terrabytes.
*
* The space maps allocate space linearly from front to back. Space that
* is freed in a transaction is never recycled within that transaction.
* To try and avoid fragmenting _free_ space the allocator always goes
* back and fills in gaps.
*
* All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
* from the block manager.
*--------------------------------------------------------------------------
*/
#define DM_MSG_PREFIX "thin metadata"
#define THIN_SUPERBLOCK_MAGIC 27022010
#define THIN_SUPERBLOCK_LOCATION 0
#define THIN_VERSION 2
#define SECTOR_TO_BLOCK_SHIFT 3
/*
* For btree insert:
* 3 for btree insert +
* 2 for btree lookup used within space map
* For btree remove:
* 2 for shadow spine +
* 4 for rebalance 3 child node
*/
#define THIN_MAX_CONCURRENT_LOCKS 6
/* This should be plenty */
#define SPACE_MAP_ROOT_SIZE 128
/*
* Little endian on-disk superblock and device details.
*/
struct thin_disk_superblock {
__le32 csum; /* Checksum of superblock except for this field. */
__le32 flags;
__le64 blocknr; /* This block number, dm_block_t. */
__u8 uuid[16];
__le64 magic;
__le32 version;
__le32 time;
__le64 trans_id;
/*
* Root held by userspace transactions.
*/
__le64 held_root;
__u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
/*
* 2-level btree mapping (dev_id, (dev block, time)) -> data block
*/
__le64 data_mapping_root;
/*
* Device detail root mapping dev_id -> device_details
*/
__le64 device_details_root;
__le32 data_block_size; /* In 512-byte sectors. */
__le32 metadata_block_size; /* In 512-byte sectors. */
__le64 metadata_nr_blocks;
__le32 compat_flags;
__le32 compat_ro_flags;
__le32 incompat_flags;
} __packed;
struct disk_device_details {
__le64 mapped_blocks;
__le64 transaction_id; /* When created. */
__le32 creation_time;
__le32 snapshotted_time;
} __packed;
struct dm_pool_metadata {
struct hlist_node hash;
struct block_device *bdev;
struct dm_block_manager *bm;
struct dm_space_map *metadata_sm;
struct dm_space_map *data_sm;
struct dm_transaction_manager *tm;
struct dm_transaction_manager *nb_tm;
/*
* Two-level btree.
* First level holds thin_dev_t.
* Second level holds mappings.
*/
struct dm_btree_info info;
/*
* Non-blocking version of the above.
*/
struct dm_btree_info nb_info;
/*
* Just the top level for deleting whole devices.
*/
struct dm_btree_info tl_info;
/*
* Just the bottom level for creating new devices.
*/
struct dm_btree_info bl_info;
/*
* Describes the device details btree.
*/
struct dm_btree_info details_info;
struct rw_semaphore root_lock;
uint32_t time;
dm_block_t root;
dm_block_t details_root;
struct list_head thin_devices;
uint64_t trans_id;
unsigned long flags;
sector_t data_block_size;
/*
* Pre-commit callback.
*
* This allows the thin provisioning target to run a callback before
* the metadata are committed.
*/
dm_pool_pre_commit_fn pre_commit_fn;
void *pre_commit_context;
/*
* We reserve a section of the metadata for commit overhead.
* All reported space does *not* include this.
*/
dm_block_t metadata_reserve;
/*
* Set if a transaction has to be aborted but the attempt to roll back
* to the previous (good) transaction failed. The only pool metadata
* operation possible in this state is the closing of the device.
*/
bool fail_io:1;
/*
* Set once a thin-pool has been accessed through one of the interfaces
* that imply the pool is in-service (e.g. thin devices created/deleted,
* thin-pool message, metadata snapshots, etc).
*/
bool in_service:1;
/*
* Reading the space map roots can fail, so we read it into these
* buffers before the superblock is locked and updated.
*/
__u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
};
struct dm_thin_device {
struct list_head list;
struct dm_pool_metadata *pmd;
dm_thin_id id;
int open_count;
bool changed:1;
bool aborted_with_changes:1;
uint64_t mapped_blocks;
uint64_t transaction_id;
uint32_t creation_time;
uint32_t snapshotted_time;
};
/*
*--------------------------------------------------------------
* superblock validator
*--------------------------------------------------------------
*/
#define SUPERBLOCK_CSUM_XOR 160774
static void sb_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct thin_disk_superblock *disk_super = dm_block_data(b);
disk_super->blocknr = cpu_to_le64(dm_block_location(b));
disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
}
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct thin_disk_superblock *disk_super = dm_block_data(b);
__le32 csum_le;
if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
DMERR("%s failed: blocknr %llu: wanted %llu",
__func__, le64_to_cpu(disk_super->blocknr),
(unsigned long long)dm_block_location(b));
return -ENOTBLK;
}
if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
DMERR("%s failed: magic %llu: wanted %llu",
__func__, le64_to_cpu(disk_super->magic),
(unsigned long long)THIN_SUPERBLOCK_MAGIC);
return -EILSEQ;
}
csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
if (csum_le != disk_super->csum) {
DMERR("%s failed: csum %u: wanted %u",
__func__, le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check
};
/*
*--------------------------------------------------------------
* Methods for the btree value types
*--------------------------------------------------------------
*/
static uint64_t pack_block_time(dm_block_t b, uint32_t t)
{
return (b << 24) | t;
}
static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
{
*b = v >> 24;
*t = v & ((1 << 24) - 1);
}
/*
* It's more efficient to call dm_sm_{inc,dec}_blocks as few times as
* possible. 'with_runs' reads contiguous runs of blocks, and calls the
* given sm function.
*/
typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t);
static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned int count, run_fn fn)
{
uint64_t b, begin, end;
uint32_t t;
bool in_run = false;
unsigned int i;
for (i = 0; i < count; i++, value_le++) {
/* We know value_le is 8 byte aligned */
unpack_block_time(le64_to_cpu(*value_le), &b, &t);
if (in_run) {
if (b == end) {
end++;
} else {
fn(sm, begin, end);
begin = b;
end = b + 1;
}
} else {
in_run = true;
begin = b;
end = b + 1;
}
}
if (in_run)
fn(sm, begin, end);
}
static void data_block_inc(void *context, const void *value_le, unsigned int count)
{
with_runs((struct dm_space_map *) context,
(const __le64 *) value_le, count, dm_sm_inc_blocks);
}
static void data_block_dec(void *context, const void *value_le, unsigned int count)
{
with_runs((struct dm_space_map *) context,
(const __le64 *) value_le, count, dm_sm_dec_blocks);
}
static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
{
__le64 v1_le, v2_le;
uint64_t b1, b2;
uint32_t t;
memcpy(&v1_le, value1_le, sizeof(v1_le));
memcpy(&v2_le, value2_le, sizeof(v2_le));
unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
return b1 == b2;
}
static void subtree_inc(void *context, const void *value, unsigned int count)
{
struct dm_btree_info *info = context;
const __le64 *root_le = value;
unsigned int i;
for (i = 0; i < count; i++, root_le++)
dm_tm_inc(info->tm, le64_to_cpu(*root_le));
}
static void subtree_dec(void *context, const void *value, unsigned int count)
{
struct dm_btree_info *info = context;
const __le64 *root_le = value;
unsigned int i;
for (i = 0; i < count; i++, root_le++)
if (dm_btree_del(info, le64_to_cpu(*root_le)))
DMERR("btree delete failed");
}
static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
{
__le64 v1_le, v2_le;
memcpy(&v1_le, value1_le, sizeof(v1_le));
memcpy(&v2_le, value2_le, sizeof(v2_le));
return v1_le == v2_le;
}
/*----------------------------------------------------------------*/
/*
* Variant that is used for in-core only changes or code that
* shouldn't put the pool in service on its own (e.g. commit).
*/
static inline void pmd_write_lock_in_core(struct dm_pool_metadata *pmd)
__acquires(pmd->root_lock)
{
down_write(&pmd->root_lock);
}
static inline void pmd_write_lock(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
if (unlikely(!pmd->in_service))
pmd->in_service = true;
}
static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)
__releases(pmd->root_lock)
{
up_write(&pmd->root_lock);
}
/*----------------------------------------------------------------*/
static int superblock_lock_zero(struct dm_pool_metadata *pmd,
struct dm_block **sblock)
{
return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock(struct dm_pool_metadata *pmd,
struct dm_block **sblock)
{
return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
{
int r;
unsigned int i;
struct dm_block *b;
__le64 *data_le, zero = cpu_to_le64(0);
unsigned int block_size = dm_bm_block_size(bm) / sizeof(__le64);
/*
* We can't use a validator here - it may be all zeroes.
*/
r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
if (r)
return r;
data_le = dm_block_data(b);
*result = 1;
for (i = 0; i < block_size; i++) {
if (data_le[i] != zero) {
*result = 0;
break;
}
}
dm_bm_unlock(b);
return 0;
}
static void __setup_btree_details(struct dm_pool_metadata *pmd)
{
pmd->info.tm = pmd->tm;
pmd->info.levels = 2;
pmd->info.value_type.context = pmd->data_sm;
pmd->info.value_type.size = sizeof(__le64);
pmd->info.value_type.inc = data_block_inc;
pmd->info.value_type.dec = data_block_dec;
pmd->info.value_type.equal = data_block_equal;
memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
pmd->nb_info.tm = pmd->nb_tm;
pmd->tl_info.tm = pmd->tm;
pmd->tl_info.levels = 1;
pmd->tl_info.value_type.context = &pmd->bl_info;
pmd->tl_info.value_type.size = sizeof(__le64);
pmd->tl_info.value_type.inc = subtree_inc;
pmd->tl_info.value_type.dec = subtree_dec;
pmd->tl_info.value_type.equal = subtree_equal;
pmd->bl_info.tm = pmd->tm;
pmd->bl_info.levels = 1;
pmd->bl_info.value_type.context = pmd->data_sm;
pmd->bl_info.value_type.size = sizeof(__le64);
pmd->bl_info.value_type.inc = data_block_inc;
pmd->bl_info.value_type.dec = data_block_dec;
pmd->bl_info.value_type.equal = data_block_equal;
pmd->details_info.tm = pmd->tm;
pmd->details_info.levels = 1;
pmd->details_info.value_type.context = NULL;
pmd->details_info.value_type.size = sizeof(struct disk_device_details);
pmd->details_info.value_type.inc = NULL;
pmd->details_info.value_type.dec = NULL;
pmd->details_info.value_type.equal = NULL;
}
static int save_sm_roots(struct dm_pool_metadata *pmd)
{
int r;
size_t len;
r = dm_sm_root_size(pmd->metadata_sm, &len);
if (r < 0)
return r;
r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
if (r < 0)
return r;
r = dm_sm_root_size(pmd->data_sm, &len);
if (r < 0)
return r;
return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
}
static void copy_sm_roots(struct dm_pool_metadata *pmd,
struct thin_disk_superblock *disk)
{
memcpy(&disk->metadata_space_map_root,
&pmd->metadata_space_map_root,
sizeof(pmd->metadata_space_map_root));
memcpy(&disk->data_space_map_root,
&pmd->data_space_map_root,
sizeof(pmd->data_space_map_root));
}
static int __write_initial_superblock(struct dm_pool_metadata *pmd)
{
int r;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
sector_t bdev_size = bdev_nr_sectors(pmd->bdev);
if (bdev_size > THIN_METADATA_MAX_SECTORS)
bdev_size = THIN_METADATA_MAX_SECTORS;
r = dm_sm_commit(pmd->data_sm);
if (r < 0)
return r;
r = dm_tm_pre_commit(pmd->tm);
if (r < 0)
return r;
r = save_sm_roots(pmd);
if (r < 0)
return r;
r = superblock_lock_zero(pmd, &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(THIN_SUPERBLOCK_MAGIC);
disk_super->version = cpu_to_le32(THIN_VERSION);
disk_super->time = 0;
disk_super->trans_id = 0;
disk_super->held_root = 0;
copy_sm_roots(pmd, disk_super);
disk_super->data_mapping_root = cpu_to_le64(pmd->root);
disk_super->device_details_root = cpu_to_le64(pmd->details_root);
disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
return dm_tm_commit(pmd->tm, sblock);
}
static int __format_metadata(struct dm_pool_metadata *pmd)
{
int r;
r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&pmd->tm, &pmd->metadata_sm);
if (r < 0) {
pmd->tm = NULL;
pmd->metadata_sm = NULL;
DMERR("tm_create_with_sm failed");
return r;
}
pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
if (IS_ERR(pmd->data_sm)) {
DMERR("sm_disk_create failed");
r = PTR_ERR(pmd->data_sm);
pmd->data_sm = NULL;
goto bad_cleanup_tm;
}
pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
if (!pmd->nb_tm) {
DMERR("could not create non-blocking clone tm");
r = -ENOMEM;
goto bad_cleanup_data_sm;
}
__setup_btree_details(pmd);
r = dm_btree_empty(&pmd->info, &pmd->root);
if (r < 0)
goto bad_cleanup_nb_tm;
r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
if (r < 0) {
DMERR("couldn't create devices root");
goto bad_cleanup_nb_tm;
}
r = __write_initial_superblock(pmd);
if (r)
goto bad_cleanup_nb_tm;
return 0;
bad_cleanup_nb_tm:
dm_tm_destroy(pmd->nb_tm);
pmd->nb_tm = NULL;
bad_cleanup_data_sm:
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
bad_cleanup_tm:
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
return r;
}
static int __check_incompat_features(struct thin_disk_superblock *disk_super,
struct dm_pool_metadata *pmd)
{
uint32_t features;
features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
if (features) {
DMERR("could not access metadata due to unsupported optional features (%lx).",
(unsigned long)features);
return -EINVAL;
}
/*
* Check for read-only metadata to skip the following RDWR checks.
*/
if (bdev_read_only(pmd->bdev))
return 0;
features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
if (features) {
DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
(unsigned long)features);
return -EINVAL;
}
return 0;
}
static int __open_metadata(struct dm_pool_metadata *pmd)
{
int r;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r < 0) {
DMERR("couldn't read 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) != pmd->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)pmd->data_block_size);
r = -EINVAL;
goto bad_unlock_sblock;
}
r = __check_incompat_features(disk_super, pmd);
if (r < 0)
goto bad_unlock_sblock;
r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
disk_super->metadata_space_map_root,
sizeof(disk_super->metadata_space_map_root),
&pmd->tm, &pmd->metadata_sm);
if (r < 0) {
pmd->tm = NULL;
pmd->metadata_sm = NULL;
DMERR("tm_open_with_sm failed");
goto bad_unlock_sblock;
}
pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
sizeof(disk_super->data_space_map_root));
if (IS_ERR(pmd->data_sm)) {
DMERR("sm_disk_open failed");
r = PTR_ERR(pmd->data_sm);
pmd->data_sm = NULL;
goto bad_cleanup_tm;
}
pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
if (!pmd->nb_tm) {
DMERR("could not create non-blocking clone tm");
r = -ENOMEM;
goto bad_cleanup_data_sm;
}
/*
* For pool metadata opening process, root setting is redundant
* because it will be set again in __begin_transaction(). But dm
* pool aborting process really needs to get last transaction's
* root to avoid accessing broken btree.
*/
pmd->root = le64_to_cpu(disk_super->data_mapping_root);
pmd->details_root = le64_to_cpu(disk_super->device_details_root);
__setup_btree_details(pmd);
dm_bm_unlock(sblock);
return 0;
bad_cleanup_data_sm:
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
bad_cleanup_tm:
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
bad_unlock_sblock:
dm_bm_unlock(sblock);
return r;
}
static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
{
int r, unformatted;
r = __superblock_all_zeroes(pmd->bm, &unformatted);
if (r)
return r;
if (unformatted)
return format_device ? __format_metadata(pmd) : -EPERM;
return __open_metadata(pmd);
}
static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
{
int r;
pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
THIN_MAX_CONCURRENT_LOCKS);
if (IS_ERR(pmd->bm)) {
DMERR("could not create block manager");
r = PTR_ERR(pmd->bm);
pmd->bm = NULL;
return r;
}
r = __open_or_format_metadata(pmd, format_device);
if (r) {
dm_block_manager_destroy(pmd->bm);
pmd->bm = NULL;
}
return r;
}
static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd,
bool destroy_bm)
{
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
dm_tm_destroy(pmd->nb_tm);
pmd->nb_tm = NULL;
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
if (destroy_bm)
dm_block_manager_destroy(pmd->bm);
}
static int __begin_transaction(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
/*
* We re-read the superblock every time. Shouldn't need to do this
* really.
*/
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
pmd->time = le32_to_cpu(disk_super->time);
pmd->root = le64_to_cpu(disk_super->data_mapping_root);
pmd->details_root = le64_to_cpu(disk_super->device_details_root);
pmd->trans_id = le64_to_cpu(disk_super->trans_id);
pmd->flags = le32_to_cpu(disk_super->flags);
pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
dm_bm_unlock(sblock);
return 0;
}
static int __write_changed_details(struct dm_pool_metadata *pmd)
{
int r;
struct dm_thin_device *td, *tmp;
struct disk_device_details details;
uint64_t key;
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (!td->changed)
continue;
key = td->id;
details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
details.transaction_id = cpu_to_le64(td->transaction_id);
details.creation_time = cpu_to_le32(td->creation_time);
details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
__dm_bless_for_disk(&details);
r = dm_btree_insert(&pmd->details_info, pmd->details_root,
&key, &details, &pmd->details_root);
if (r)
return r;
if (td->open_count)
td->changed = false;
else {
list_del(&td->list);
kfree(td);
}
}
return 0;
}
static int __commit_transaction(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
/*
* We need to know if the thin_disk_superblock exceeds a 512-byte sector.
*/
BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
BUG_ON(!rwsem_is_locked(&pmd->root_lock));
if (unlikely(!pmd->in_service))
return 0;
if (pmd->pre_commit_fn) {
r = pmd->pre_commit_fn(pmd->pre_commit_context);
if (r < 0) {
DMERR("pre-commit callback failed");
return r;
}
}
r = __write_changed_details(pmd);
if (r < 0)
return r;
r = dm_sm_commit(pmd->data_sm);
if (r < 0)
return r;
r = dm_tm_pre_commit(pmd->tm);
if (r < 0)
return r;
r = save_sm_roots(pmd);
if (r < 0)
return r;
r = superblock_lock(pmd, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
disk_super->time = cpu_to_le32(pmd->time);
disk_super->data_mapping_root = cpu_to_le64(pmd->root);
disk_super->device_details_root = cpu_to_le64(pmd->details_root);
disk_super->trans_id = cpu_to_le64(pmd->trans_id);
disk_super->flags = cpu_to_le32(pmd->flags);
copy_sm_roots(pmd, disk_super);
return dm_tm_commit(pmd->tm, sblock);
}
static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
{
int r;
dm_block_t total;
dm_block_t max_blocks = 4096; /* 16M */
r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
if (r) {
DMERR("could not get size of metadata device");
pmd->metadata_reserve = max_blocks;
} else
pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
}
struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
sector_t data_block_size,
bool format_device)
{
int r;
struct dm_pool_metadata *pmd;
pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
if (!pmd) {
DMERR("could not allocate metadata struct");
return ERR_PTR(-ENOMEM);
}
init_rwsem(&pmd->root_lock);
pmd->time = 0;
INIT_LIST_HEAD(&pmd->thin_devices);
pmd->fail_io = false;
pmd->in_service = false;
pmd->bdev = bdev;
pmd->data_block_size = data_block_size;
pmd->pre_commit_fn = NULL;
pmd->pre_commit_context = NULL;
r = __create_persistent_data_objects(pmd, format_device);
if (r) {
kfree(pmd);
return ERR_PTR(r);
}
r = __begin_transaction(pmd);
if (r < 0) {
if (dm_pool_metadata_close(pmd) < 0)
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
return ERR_PTR(r);
}
__set_metadata_reserve(pmd);
return pmd;
}
int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
{
int r;
unsigned int open_devices = 0;
struct dm_thin_device *td, *tmp;
down_read(&pmd->root_lock);
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (td->open_count)
open_devices++;
else {
list_del(&td->list);
kfree(td);
}
}
up_read(&pmd->root_lock);
if (open_devices) {
DMERR("attempt to close pmd when %u device(s) are still open",
open_devices);
return -EBUSY;
}
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) {
r = __commit_transaction(pmd);
if (r < 0)
DMWARN("%s: __commit_transaction() failed, error = %d",
__func__, r);
}
pmd_write_unlock(pmd);
__destroy_persistent_data_objects(pmd, true);
kfree(pmd);
return 0;
}
/*
* __open_device: Returns @td corresponding to device with id @dev,
* creating it if @create is set and incrementing @td->open_count.
* On failure, @td is undefined.
*/
static int __open_device(struct dm_pool_metadata *pmd,
dm_thin_id dev, int create,
struct dm_thin_device **td)
{
int r, changed = 0;
struct dm_thin_device *td2;
uint64_t key = dev;
struct disk_device_details details_le;
/*
* If the device is already open, return it.
*/
list_for_each_entry(td2, &pmd->thin_devices, list)
if (td2->id == dev) {
/*
* May not create an already-open device.
*/
if (create)
return -EEXIST;
td2->open_count++;
*td = td2;
return 0;
}
/*
* Check the device exists.
*/
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&key, &details_le);
if (r) {
if (r != -ENODATA || !create)
return r;
/*
* Create new device.
*/
changed = 1;
details_le.mapped_blocks = 0;
details_le.transaction_id = cpu_to_le64(pmd->trans_id);
details_le.creation_time = cpu_to_le32(pmd->time);
details_le.snapshotted_time = cpu_to_le32(pmd->time);
}
*td = kmalloc(sizeof(**td), GFP_NOIO);
if (!*td)
return -ENOMEM;
(*td)->pmd = pmd;
(*td)->id = dev;
(*td)->open_count = 1;
(*td)->changed = changed;
(*td)->aborted_with_changes = false;
(*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
(*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
(*td)->creation_time = le32_to_cpu(details_le.creation_time);
(*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
list_add(&(*td)->list, &pmd->thin_devices);
return 0;
}
static void __close_device(struct dm_thin_device *td)
{
--td->open_count;
}
static int __create_thin(struct dm_pool_metadata *pmd,
dm_thin_id dev)
{
int r;
dm_block_t dev_root;
uint64_t key = dev;
struct dm_thin_device *td;
__le64 value;
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&key, NULL);
if (!r)
return -EEXIST;
/*
* Create an empty btree for the mappings.
*/
r = dm_btree_empty(&pmd->bl_info, &dev_root);
if (r)
return r;
/*
* Insert it into the main mapping tree.
*/
value = cpu_to_le64(dev_root);
__dm_bless_for_disk(&value);
r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
if (r) {
dm_btree_del(&pmd->bl_info, dev_root);
return r;
}
r = __open_device(pmd, dev, 1, &td);
if (r) {
dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
dm_btree_del(&pmd->bl_info, dev_root);
return r;
}
__close_device(td);
return r;
}
int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __create_thin(pmd, dev);
pmd_write_unlock(pmd);
return r;
}
static int __set_snapshot_details(struct dm_pool_metadata *pmd,
struct dm_thin_device *snap,
dm_thin_id origin, uint32_t time)
{
int r;
struct dm_thin_device *td;
r = __open_device(pmd, origin, 0, &td);
if (r)
return r;
td->changed = true;
td->snapshotted_time = time;
snap->mapped_blocks = td->mapped_blocks;
snap->snapshotted_time = time;
__close_device(td);
return 0;
}
static int __create_snap(struct dm_pool_metadata *pmd,
dm_thin_id dev, dm_thin_id origin)
{
int r;
dm_block_t origin_root;
uint64_t key = origin, dev_key = dev;
struct dm_thin_device *td;
__le64 value;
/* check this device is unused */
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&dev_key, NULL);
if (!r)
return -EEXIST;
/* find the mapping tree for the origin */
r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
if (r)
return r;
origin_root = le64_to_cpu(value);
/* clone the origin, an inc will do */
dm_tm_inc(pmd->tm, origin_root);
/* insert into the main mapping tree */
value = cpu_to_le64(origin_root);
__dm_bless_for_disk(&value);
key = dev;
r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
if (r) {
dm_tm_dec(pmd->tm, origin_root);
return r;
}
pmd->time++;
r = __open_device(pmd, dev, 1, &td);
if (r)
goto bad;
r = __set_snapshot_details(pmd, td, origin, pmd->time);
__close_device(td);
if (r)
goto bad;
return 0;
bad:
dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
dm_btree_remove(&pmd->details_info, pmd->details_root,
&key, &pmd->details_root);
return r;
}
int dm_pool_create_snap(struct dm_pool_metadata *pmd,
dm_thin_id dev,
dm_thin_id origin)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __create_snap(pmd, dev, origin);
pmd_write_unlock(pmd);
return r;
}
static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
{
int r;
uint64_t key = dev;
struct dm_thin_device *td;
/* TODO: failure should mark the transaction invalid */
r = __open_device(pmd, dev, 0, &td);
if (r)
return r;
if (td->open_count > 1) {
__close_device(td);
return -EBUSY;
}
list_del(&td->list);
kfree(td);
r = dm_btree_remove(&pmd->details_info, pmd->details_root,
&key, &pmd->details_root);
if (r)
return r;
r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
if (r)
return r;
return 0;
}
int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
dm_thin_id dev)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __delete_device(pmd, dev);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
uint64_t current_id,
uint64_t new_id)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (pmd->fail_io)
goto out;
if (pmd->trans_id != current_id) {
DMERR("mismatched transaction id");
goto out;
}
pmd->trans_id = new_id;
r = 0;
out:
pmd_write_unlock(pmd);
return r;
}
int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
uint64_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
*result = pmd->trans_id;
r = 0;
}
up_read(&pmd->root_lock);
return r;
}
static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
{
int r, inc;
struct thin_disk_superblock *disk_super;
struct dm_block *copy, *sblock;
dm_block_t held_root;
/*
* We commit to ensure the btree roots which we increment in a
* moment are up to date.
*/
r = __commit_transaction(pmd);
if (r < 0) {
DMWARN("%s: __commit_transaction() failed, error = %d",
__func__, r);
return r;
}
/*
* Copy the superblock.
*/
dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &copy, &inc);
if (r)
return r;
BUG_ON(!inc);
held_root = dm_block_location(copy);
disk_super = dm_block_data(copy);
if (le64_to_cpu(disk_super->held_root)) {
DMWARN("Pool metadata snapshot already exists: release this before taking another.");
dm_tm_dec(pmd->tm, held_root);
dm_tm_unlock(pmd->tm, copy);
return -EBUSY;
}
/*
* Wipe the spacemap since we're not publishing this.
*/
memset(&disk_super->data_space_map_root, 0,
sizeof(disk_super->data_space_map_root));
memset(&disk_super->metadata_space_map_root, 0,
sizeof(disk_super->metadata_space_map_root));
/*
* Increment the data structures that need to be preserved.
*/
dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
dm_tm_unlock(pmd->tm, copy);
/*
* Write the held root into the superblock.
*/
r = superblock_lock(pmd, &sblock);
if (r) {
dm_tm_dec(pmd->tm, held_root);
return r;
}
disk_super = dm_block_data(sblock);
disk_super->held_root = cpu_to_le64(held_root);
dm_bm_unlock(sblock);
return 0;
}
int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __reserve_metadata_snap(pmd);
pmd_write_unlock(pmd);
return r;
}
static int __release_metadata_snap(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock, *copy;
dm_block_t held_root;
r = superblock_lock(pmd, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
held_root = le64_to_cpu(disk_super->held_root);
disk_super->held_root = cpu_to_le64(0);
dm_bm_unlock(sblock);
if (!held_root) {
DMWARN("No pool metadata snapshot found: nothing to release.");
return -EINVAL;
}
r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
if (r)
return r;
disk_super = dm_block_data(copy);
dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
dm_sm_dec_block(pmd->metadata_sm, held_root);
dm_tm_unlock(pmd->tm, copy);
return 0;
}
int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __release_metadata_snap(pmd);
pmd_write_unlock(pmd);
return r;
}
static int __get_metadata_snap(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
*result = le64_to_cpu(disk_super->held_root);
dm_bm_unlock(sblock);
return 0;
}
int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = __get_metadata_snap(pmd, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
struct dm_thin_device **td)
{
int r = -EINVAL;
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io)
r = __open_device(pmd, dev, 0, td);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_close_thin_device(struct dm_thin_device *td)
{
pmd_write_lock_in_core(td->pmd);
__close_device(td);
pmd_write_unlock(td->pmd);
return 0;
}
dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
{
return td->id;
}
/*
* Check whether @time (of block creation) is older than @td's last snapshot.
* If so then the associated block is shared with the last snapshot device.
* Any block on a device created *after* the device last got snapshotted is
* necessarily not shared.
*/
static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
{
return td->snapshotted_time > time;
}
static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
struct dm_thin_lookup_result *result)
{
uint64_t block_time = 0;
dm_block_t exception_block;
uint32_t exception_time;
block_time = le64_to_cpu(value);
unpack_block_time(block_time, &exception_block, &exception_time);
result->block = exception_block;
result->shared = __snapshotted_since(td, exception_time);
}
static int __find_block(struct dm_thin_device *td, dm_block_t block,
int can_issue_io, struct dm_thin_lookup_result *result)
{
int r;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
struct dm_btree_info *info;
if (can_issue_io)
info = &pmd->info;
else
info = &pmd->nb_info;
r = dm_btree_lookup(info, pmd->root, keys, &value);
if (!r)
unpack_lookup_result(td, value, result);
return r;
}
int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
int can_issue_io, struct dm_thin_lookup_result *result)
{
int r;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (pmd->fail_io) {
up_read(&pmd->root_lock);
return -EINVAL;
}
r = __find_block(td, block, can_issue_io, result);
up_read(&pmd->root_lock);
return r;
}
static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
dm_block_t *vblock,
struct dm_thin_lookup_result *result)
{
int r;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
if (!r)
unpack_lookup_result(td, value, result);
return r;
}
static int __find_mapped_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end,
dm_block_t *thin_begin, dm_block_t *thin_end,
dm_block_t *pool_begin, bool *maybe_shared)
{
int r;
dm_block_t pool_end;
struct dm_thin_lookup_result lookup;
if (end < begin)
return -ENODATA;
r = __find_next_mapped_block(td, begin, &begin, &lookup);
if (r)
return r;
if (begin >= end)
return -ENODATA;
*thin_begin = begin;
*pool_begin = lookup.block;
*maybe_shared = lookup.shared;
begin++;
pool_end = *pool_begin + 1;
while (begin != end) {
r = __find_block(td, begin, true, &lookup);
if (r) {
if (r == -ENODATA)
break;
return r;
}
if ((lookup.block != pool_end) ||
(lookup.shared != *maybe_shared))
break;
pool_end++;
begin++;
}
*thin_end = begin;
return 0;
}
int dm_thin_find_mapped_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end,
dm_block_t *thin_begin, dm_block_t *thin_end,
dm_block_t *pool_begin, bool *maybe_shared)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
pool_begin, maybe_shared);
}
up_read(&pmd->root_lock);
return r;
}
static int __insert(struct dm_thin_device *td, dm_block_t block,
dm_block_t data_block)
{
int r, inserted;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
value = cpu_to_le64(pack_block_time(data_block, pmd->time));
__dm_bless_for_disk(&value);
r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
&pmd->root, &inserted);
if (r)
return r;
td->changed = true;
if (inserted)
td->mapped_blocks++;
return 0;
}
int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
dm_block_t data_block)
{
int r = -EINVAL;
pmd_write_lock(td->pmd);
if (!td->pmd->fail_io)
r = __insert(td, block, data_block);
pmd_write_unlock(td->pmd);
return r;
}
static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
{
int r;
unsigned int count, total_count = 0;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[1] = { td->id };
__le64 value;
dm_block_t mapping_root;
/*
* Find the mapping tree
*/
r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
if (r)
return r;
/*
* Remove from the mapping tree, taking care to inc the
* ref count so it doesn't get deleted.
*/
mapping_root = le64_to_cpu(value);
dm_tm_inc(pmd->tm, mapping_root);
r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
if (r)
return r;
/*
* Remove leaves stops at the first unmapped entry, so we have to
* loop round finding mapped ranges.
*/
while (begin < end) {
r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
if (r == -ENODATA)
break;
if (r)
return r;
if (begin >= end)
break;
r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
if (r)
return r;
total_count += count;
}
td->mapped_blocks -= total_count;
td->changed = true;
/*
* Reinsert the mapping tree.
*/
value = cpu_to_le64(mapping_root);
__dm_bless_for_disk(&value);
return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
}
int dm_thin_remove_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end)
{
int r = -EINVAL;
pmd_write_lock(td->pmd);
if (!td->pmd->fail_io)
r = __remove_range(td, begin, end);
pmd_write_unlock(td->pmd);
return r;
}
int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
{
int r = -EINVAL;
uint32_t ref_count;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
if (!r)
*result = (ref_count > 1);
}
up_read(&pmd->root_lock);
return r;
}
int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_inc_blocks(pmd->data_sm, b, e);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_dec_blocks(pmd->data_sm, b, e);
pmd_write_unlock(pmd);
return r;
}
bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
{
int r;
down_read(&td->pmd->root_lock);
r = td->changed;
up_read(&td->pmd->root_lock);
return r;
}
bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
{
bool r = false;
struct dm_thin_device *td, *tmp;
down_read(&pmd->root_lock);
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (td->changed) {
r = td->changed;
break;
}
}
up_read(&pmd->root_lock);
return r;
}
bool dm_thin_aborted_changes(struct dm_thin_device *td)
{
bool r;
down_read(&td->pmd->root_lock);
r = td->aborted_with_changes;
up_read(&td->pmd->root_lock);
return r;
}
int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_new_block(pmd->data_sm, result);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
/*
* Care is taken to not have commit be what
* triggers putting the thin-pool in-service.
*/
pmd_write_lock_in_core(pmd);
if (pmd->fail_io)
goto out;
r = __commit_transaction(pmd);
if (r < 0)
goto out;
/*
* Open the next transaction.
*/
r = __begin_transaction(pmd);
out:
pmd_write_unlock(pmd);
return r;
}
static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
{
struct dm_thin_device *td;
list_for_each_entry(td, &pmd->thin_devices, list)
td->aborted_with_changes = td->changed;
}
int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
/* fail_io is double-checked with pmd->root_lock held below */
if (unlikely(pmd->fail_io))
return r;
pmd_write_lock(pmd);
if (pmd->fail_io) {
pmd_write_unlock(pmd);
return r;
}
__set_abort_with_changes_flags(pmd);
/* destroy data_sm/metadata_sm/nb_tm/tm */
__destroy_persistent_data_objects(pmd, false);
/* reset bm */
dm_block_manager_reset(pmd->bm);
/* rebuild data_sm/metadata_sm/nb_tm/tm */
r = __open_or_format_metadata(pmd, false);
if (r)
pmd->fail_io = true;
pmd_write_unlock(pmd);
return r;
}
int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_free(pmd->data_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_free(pmd->metadata_sm, result);
if (!r) {
if (*result < pmd->metadata_reserve)
*result = 0;
else
*result -= pmd->metadata_reserve;
}
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_blocks(pmd->data_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
*result = td->mapped_blocks;
r = 0;
}
up_read(&pmd->root_lock);
return r;
}
static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
{
int r;
__le64 value_le;
dm_block_t thin_root;
struct dm_pool_metadata *pmd = td->pmd;
r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
if (r)
return r;
thin_root = le64_to_cpu(value_le);
return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
}
int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
dm_block_t *result)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = __highest_block(td, result);
up_read(&pmd->root_lock);
return r;
}
static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
{
int r;
dm_block_t old_count;
r = dm_sm_get_nr_blocks(sm, &old_count);
if (r)
return r;
if (new_count == old_count)
return 0;
if (new_count < old_count) {
DMERR("cannot reduce size of space map");
return -EINVAL;
}
return dm_sm_extend(sm, new_count - old_count);
}
int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __resize_space_map(pmd->data_sm, new_count);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io) {
r = __resize_space_map(pmd->metadata_sm, new_count);
if (!r)
__set_metadata_reserve(pmd);
}
pmd_write_unlock(pmd);
return r;
}
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
dm_bm_set_read_only(pmd->bm);
pmd_write_unlock(pmd);
}
void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
dm_bm_set_read_write(pmd->bm);
pmd_write_unlock(pmd);
}
int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
dm_block_t threshold,
dm_sm_threshold_fn fn,
void *context)
{
int r = -EINVAL;
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io) {
r = dm_sm_register_threshold_callback(pmd->metadata_sm,
threshold, fn, context);
}
pmd_write_unlock(pmd);
return r;
}
void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
dm_pool_pre_commit_fn fn,
void *context)
{
pmd_write_lock_in_core(pmd);
pmd->pre_commit_fn = fn;
pmd->pre_commit_context = context;
pmd_write_unlock(pmd);
}
int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
pmd_write_lock(pmd);
if (pmd->fail_io)
goto out;
pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
r = superblock_lock(pmd, &sblock);
if (r) {
DMERR("couldn't lock superblock");
goto out;
}
disk_super = dm_block_data(sblock);
disk_super->flags = cpu_to_le32(pmd->flags);
dm_bm_unlock(sblock);
out:
pmd_write_unlock(pmd);
return r;
}
bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
{
bool needs_check;
down_read(&pmd->root_lock);
needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
up_read(&pmd->root_lock);
return needs_check;
}
void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
{
down_read(&pmd->root_lock);
if (!pmd->fail_io)
dm_tm_issue_prefetches(pmd->tm);
up_read(&pmd->root_lock);
}
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