v4.19.13 snapshot.
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
new file mode 100644
index 0000000..6fc9383
--- /dev/null
+++ b/drivers/md/dm-cache-metadata.c
@@ -0,0 +1,1810 @@
+/*
+ * 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 = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
+
+ /* 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 (get_disk_ro(cmd->bdev->bd_disk))
+ 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");
+ return PTR_ERR(cmd->bm);
+ }
+
+ r = __open_or_format_metadata(cmd, may_format_device);
+ if (r)
+ dm_block_manager_destroy(cmd->bm);
+
+ 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 < from_dblock(cmd->discard_nr_blocks); b++) {
+ r = fn(context, cmd->discard_block_size, to_dblock(b),
+ dm_bitset_cursor_get_value(&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;
+}