Release 4.11 drivers/md/dm-cache-metadata.c

Directory: drivers/md
/*
 * 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>

/*----------------------------------------------------------------*/


#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


#define CACHE_METADATA_CACHE_SIZE 64

/*
 *  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 {
	
atomic_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));
}

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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;
}

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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);
}

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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);
}

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static int superblock_lock_zero(struct dm_cache_metadata *cmd,
				struct dm_block **sblock)
{
	return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
				     &sb_validator, sblock);
}

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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);
}

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/*----------------------------------------------------------------*/



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;
}

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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);
	}
}

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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);
}

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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));
}

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static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
{
	return cmd->version >= 2;
}

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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 = 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);
}

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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;
}

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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;
}

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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;
}

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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);
}

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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_METADATA_CACHE_SIZE,
					  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;
}

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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);
}

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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);
}

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static unsigned long set_clean_shutdown(unsigned long flags)
{
	set_bit(CLEAN_SHUTDOWN, &flags);
	return flags;
}

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static unsigned long clear_clean_shutdown(unsigned long flags)
{
	clear_bit(CLEAN_SHUTDOWN, &flags);
	return flags;
}

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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;
}

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/*
 * 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);
}

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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;
}

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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->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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 355 87.44% 6 85.71%
Mike Snitzer 51 12.56% 1 14.29%
Total 406 100.00% 7 100.00%

/*----------------------------------------------------------------*/

/*
 * 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);
}

Contributors
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Joe Thornber 40 100.00% 1 100.00%
Total 40 100.00% 1 100.00%



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;
}

Contributors
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Joe Thornber 47 100.00% 1 100.00%
Total 47 100.00% 1 100.00%

/*----------------------------------------------------------------*/



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;
	atomic_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;
}

Contributors
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Joe Thornber 182 100.00% 5 100.00%
Total 182 100.00% 5 100.00%

/*
 * 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) {
			atomic_inc(&cmd->ref_count);
			return cmd;
		}

	return NULL;
}

Contributors
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Joe Thornber 50 100.00% 1 100.00%
Total 50 100.00% 1 100.00%



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;
}

Contributors
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Joe Thornber 142 100.00% 3 100.00%
Total 142 100.00% 3 100.00%



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;
}

Contributors
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Joe Thornber 50 98.04% 1 50.00%
Mike Snitzer 1 1.96% 1 50.00%
Total 51 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 75 100.00% 3 100.00%
Total 75 100.00% 3 100.00%



void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
{
	if (atomic_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);
	}
}

Contributors
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Joe Thornber 59 100.00% 3 100.00%
Total 59 100.00% 3 100.00%

/*
 * 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;
}

Contributors
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Joe Thornber 91 100.00% 2 100.00%
Total 91 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 103 100.00% 2 100.00%
Total 103 100.00% 2 100.00%



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;

	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;
}

Contributors
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Mike Snitzer 131 55.74% 2 50.00%
Joe Thornber 104 44.26% 2 50.00%
Total 235 100.00% 4 100.00%



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);
}

Contributors
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Joe Thornber 53 100.00% 1 100.00%
Total 53 100.00% 1 100.00%



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;
}

Contributors
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Mike Snitzer 29 60.42% 1 50.00%
Joe Thornber 19 39.58% 1 50.00%
Total 48 100.00% 2 100.00%


#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;
}

Contributors
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Mike Snitzer 39 95.12% 1 50.00%
Ahmed Samy 2 4.88% 1 50.00%
Total 41 100.00% 2 100.00%


#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;
}

Contributors
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Joe Thornber 225 100.00% 4 100.00%
Total 225 100.00% 4 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 90 100.00% 3 100.00%
Total 90 100.00% 3 100.00%



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);
}

Contributors
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Joe Thornber 37 100.00% 2 100.00%
Total 37 100.00% 2 100.00%



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);
}

Contributors
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Joe Thornber 37 100.00% 2 100.00%
Total 37 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 51 100.00% 2 100.00%
Total 51 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 43 100.00% 3 100.00%
Total 43 100.00% 3 100.00%



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;
}

Contributors
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Joe Thornber 214 100.00% 3 100.00%
Total 214 100.00% 3 100.00%



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;
}

Contributors
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Joe Thornber 44 100.00% 2 100.00%
Total 44 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 34 100.00% 2 100.00%
Total 34 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 76 100.00% 1 100.00%
Total 76 100.00% 1 100.00%



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;
}

Contributors
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Joe Thornber 38 100.00% 2 100.00%
Total 38 100.00% 2 100.00%



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;
}

Contributors
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Joe Thornber 79 100.00% 1 100.00%
Total 79 100.00% 1 100.00%



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;
}

Contributors
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Joe Thornber 43 100.00% 2 100.00%
Total 43 100.00% 2 100.00%


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;
}

Contributors
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Mike Snitzer 99 100.00% 1 100.00%
Total 99 100.00% 1 100.00%



static bool hints_array_initialized(struct dm_cache_metadata *cmd)
{
	return cmd->hint_root && cmd->policy_hint_size;
}

Contributors
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Joe Thornber 20 100.00% 1 100.00%
Total 20 100.00% 1 100.00%



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);
}

Contributors
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Joe Thornber 24 72.73% 1 50.00%
Mike Snitzer 9 27.27% 1 50.00%
Total 33 100.00% 2 100.00%



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;

	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));
		}

		r = fn(context, oblock, to_cblock(cb), flags & M_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;
}

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Joe Thornber 174 91.58% 3 75.00%
Mike Snitzer 16 8.42% 1 25.00%
Total 190 100.00% 4 100.00%



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;

	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));
		}

		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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 186 91.63% 3 60.00%
Mike Snitzer 17 8.37% 2 40.00%
Total 203 100.00% 5 100.00%



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) {
				DMERR("dm_array_cursor_next for hint failed");
				goto out;
			}
		}

		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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 408 100.00% 3 100.00%
Total 408 100.00% 3 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 47 92.16% 2 66.67%
Mike Snitzer 4 7.84% 1 33.33%
Total 51 100.00% 3 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 58 100.00% 1 100.00%
Total 58 100.00% 1 100.00%



static int __dump_mappings(struct dm_cache_metadata *cmd)
{
	return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 28 100.00% 1 100.00%
Total 28 100.00% 1 100.00%



void dm_cache_dump(struct dm_cache_metadata *cmd)
{
	READ_LOCK_VOID(cmd);
	__dump_mappings(cmd);
	READ_UNLOCK(cmd);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 25 100.00% 2 100.00%
Total 25 100.00% 2 100.00%



int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
{
	int r;

	READ_LOCK(cmd);
	r = cmd->changed;
	READ_UNLOCK(cmd);

	return r;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 32 100.00% 2 100.00%
Total 32 100.00% 2 100.00%



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;

}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 168 100.00% 2 100.00%
Total 168 100.00% 2 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 69 100.00% 2 100.00%
Total 69 100.00% 2 100.00%



static int is_dirty_callback(uint32_t index, bool *value, void *context)
{
	unsigned long *bits = context;
	*value = test_bit(index, bits);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 37 100.00% 1 100.00%
Total 37 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 94 100.00% 2 100.00%
Total 94 100.00% 2 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 64 100.00% 3 100.00%
Total 64 100.00% 3 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 32 100.00% 3 100.00%
Total 32 100.00% 3 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 32 100.00% 3 100.00%
Total 32 100.00% 3 100.00%



int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
{
	int r;
	flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
				 clear_clean_shutdown);

	WRITE_LOCK(cmd);
	r = __commit_transaction(cmd, mutator);
	if (r)
		goto out;

	r = __begin_transaction(cmd);

out:
	WRITE_UNLOCK(cmd);
	return r;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 65 100.00% 2 100.00%
Total 65 100.00% 2 100.00%



int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
					   dm_block_t *result)
{
	int r = -EINVAL;

	READ_LOCK(cmd);
	r = dm_sm_get_nr_free(cmd->metadata_sm, result);
	READ_UNLOCK(cmd);

	return r;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 44 100.00% 2 100.00%
Total 44 100.00% 2 100.00%



int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
				   dm_block_t *result)
{
	int r = -EINVAL;

	READ_LOCK(cmd);
	r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
	READ_UNLOCK(cmd);

	return r;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 44 100.00% 2 100.00%
Total 44 100.00% 2 100.00%

/*----------------------------------------------------------------*/



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 56 100.00% 2 100.00%
Total 56 100.00% 2 100.00%

/*
 * 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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 152 85.39% 3 75.00%
Mike Snitzer 26 14.61% 1 25.00%
Total 178 100.00% 4 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 40 100.00% 3 100.00%
Total 40 100.00% 3 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 45 100.00% 2 100.00%
Total 45 100.00% 2 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 95 100.00% 2 100.00%
Total 95 100.00% 2 100.00%



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;
}

Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 42 100.00% 2 100.00%
Total 42 100.00% 2 100.00%



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;
}
Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 50 100.00% 1 100.00%
Total 50 100.00% 1 100.00%

Overall Contributors
Person Tokens Prop Commits CommitProp
Joe Thornber 7167 92.66% 22 68.75%
Mike Snitzer 560 7.24% 8 25.00%
Mikulas Patocka 6 0.08% 1 3.12%
Ahmed Samy 2 0.03% 1 3.12%
Total 7735 100.00% 32 100.00%
Directory: drivers/md

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Joe Thornber	65	100.00%	1	100.00%
Total	65	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.11 drivers/md/dm-cache-metadata.c

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