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/*
* Author: Kent Overstreet <kmo@daterainc.com>
*
* GPLv2
*/
#ifndef _BCACHE_H
#define _BCACHE_H
#include <linux/types.h>
#define BITMASK(name, type, field, offset, size) \
static inline uint64_t name(const type *k) \
{ return (k->field >> offset) & ~(((uint64_t) ~0) << size); } \
\
static inline void SET_##name(type *k, uint64_t v) \
{ \
k->field &= ~(~((uint64_t) ~0 << size) << offset); \
k->field |= v << offset; \
}
static const char bcache_magic[] = {
0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81 };
/*
* Version 0: Cache device
* Version 1: Backing device
* Version 2: Seed pointer into btree node checksum
* Version 3: Cache device with new UUID format
* Version 4: Backing device with data offset
* Version 5: Cache adn backing devices with compat/incompat/ro_compat
* feature sets
*/
#define BCACHE_SB_VERSION_CDEV 0
#define BCACHE_SB_VERSION_BDEV 1
#define BCACHE_SB_VERSION_CDEV_WITH_UUID 3
#define BCACHE_SB_VERSION_BDEV_WITH_OFFSET 4
#define BCACHE_SB_VERSION_CDEV_WITH_FEATURES 5
#define BCACHE_SB_VERSION_BDEV_WITH_FEATURES 6
#define BCACHE_SB_MAX_VERSION 6
#define SB_SECTOR 8
#define SB_LABEL_SIZE 32
#define SB_JOURNAL_BUCKETS 256U
#define BDEV_DATA_START_DEFAULT 16 /* sectors */
#define SB_START (SB_SECTOR * 512)
struct cache_sb_disk {
__le64 csum;
__le64 offset; /* sector where this sb was written */
__le64 version;
__u8 magic[16];
__u8 uuid[16];
union {
__u8 set_uuid[16];
__le64 set_magic;
};
__u8 label[SB_LABEL_SIZE];
__le64 flags;
__le64 seq;
__le64 feature_compat;
__le64 feature_incompat;
__le64 feature_ro_compat;
__le64 pad[5];
union {
struct {
/* Cache devices */
__le64 nbuckets; /* device size */
__le16 block_size; /* sectors */
__le16 bucket_size; /* sectors */
__le16 nr_in_set;
__le16 nr_this_dev;
};
struct {
/* Backing devices */
__le64 data_offset;
/*
* block_size from the cache device section is still used by
* backing devices, so don't add anything here until we fix
* things to not need it for backing devices anymore
*/
};
};
__le32 last_mount; /* time overflow in y2106 */
__le16 first_bucket;
union {
__le16 njournal_buckets;
__le16 keys;
};
__le64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
__le16 obso_bucket_size_hi; /* obsoleted */
};
/*
* This is for in-memory bcache super block.
* NOTE: cache_sb is NOT exactly mapping to cache_sb_disk, the member
* size, ordering and even whole struct size may be different
* from cache_sb_disk.
*/
struct cache_sb {
__u64 offset; /* sector where this sb was written */
__u64 version;
__u8 magic[16];
__u8 uuid[16];
union {
__u8 set_uuid[16];
__u64 set_magic;
};
__u8 label[SB_LABEL_SIZE];
__u64 flags;
__u64 seq;
__u64 feature_compat;
__u64 feature_incompat;
__u64 feature_ro_compat;
union {
struct {
/* Cache devices */
__u64 nbuckets; /* device size */
__u16 block_size; /* sectors */
__u16 nr_in_set;
__u16 nr_this_dev;
__u32 bucket_size; /* sectors */
};
struct {
/* Backing devices */
__u64 data_offset;
/*
* block_size from the cache device section is still used by
* backing devices, so don't add anything here until we fix
* things to not need it for backing devices anymore
*/
};
};
__u32 last_mount; /* time overflow in y2106 */
__u16 first_bucket;
union {
__u16 njournal_buckets;
__u16 keys;
};
__u64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
};
static inline bool SB_IS_BDEV(const struct cache_sb *sb)
{
return sb->version == BCACHE_SB_VERSION_BDEV
|| sb->version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET
|| sb->version == BCACHE_SB_VERSION_BDEV_WITH_FEATURES;
}
BITMASK(CACHE_SYNC, struct cache_sb, flags, 0, 1);
BITMASK(CACHE_DISCARD, struct cache_sb, flags, 1, 1);
BITMASK(CACHE_REPLACEMENT, struct cache_sb, flags, 2, 3);
#define CACHE_REPLACEMENT_LRU 0U
#define CACHE_REPLACEMENT_FIFO 1U
#define CACHE_REPLACEMENT_RANDOM 2U
BITMASK(BDEV_CACHE_MODE, struct cache_sb, flags, 0, 4);
#define CACHE_MODE_WRITETHROUGH 0U
#define CACHE_MODE_WRITEBACK 1U
#define CACHE_MODE_WRITEAROUND 2U
#define CACHE_MODE_NONE 3U
BITMASK(BDEV_STATE, struct cache_sb, flags, 61, 2);
#define BDEV_STATE_NONE 0U
#define BDEV_STATE_CLEAN 1U
#define BDEV_STATE_DIRTY 2U
#define BDEV_STATE_STALE 3U
uint64_t crc64(const void *data, size_t len);
#define node(i, j) ((void *) ((i)->d + (j)))
#define end(i) node(i, (i)->keys)
#define csum_set(i) \
crc64(((void *) (i)) + 8, ((void *) end(i)) - (((void *) (i)) + 8))
/* Feature set definition */
#define BCH_FEATURE_COMPAT 0
#define BCH_FEATURE_RO_COMPAT 1
#define BCH_FEATURE_INCOMPAT 2
#define BCH_FEATURE_TYPE_MASK 0x03
#define BCH_FEATURE_COMPAT_SUPP 0
#define BCH_FEATURE_RO_COMPAT_SUPP 0
#define BCH_FEATURE_INCOMPAT_SUPP (BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET| \
BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE)
#define BCH_HAS_COMPAT_FEATURE(sb, mask) \
((sb)->feature_compat & (mask))
#define BCH_HAS_RO_COMPAT_FEATURE(sb, mask) \
((sb)->feature_ro_compat & (mask))
#define BCH_HAS_INCOMPAT_FEATURE(sb, mask) \
((sb)->feature_incompat & (mask))
/* Feature set definition */
/* Incompat feature set */
/* 32bit bucket size, obsoleted */
#define BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET 0x0001
/* real bucket size is (1 << bucket_size) */
#define BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE 0x0002
#define BCH_FEATURE_COMPAT_FUNCS(name, flagname) \
static inline int bch_has_feature_##name(struct cache_sb *sb) \
{ \
return (((sb)->feature_compat & \
BCH##_FEATURE_COMPAT_##flagname) != 0); \
} \
static inline void bch_set_feature_##name(struct cache_sb *sb) \
{ \
if ((sb)->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \
(sb)->version = BCACHE_SB_VERSION_CDEV_WITH_FEATURES; \
(sb)->feature_compat |= \
BCH##_FEATURE_COMPAT_##flagname; \
} \
static inline void bch_clear_feature_##name(struct cache_sb *sb) \
{ \
(sb)->feature_compat &= \
~BCH##_FEATURE_COMPAT_##flagname; \
}
#define BCH_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
static inline int bch_has_feature_##name(struct cache_sb *sb) \
{ \
return (((sb)->feature_ro_compat & \
BCH##_FEATURE_RO_COMPAT_##flagname) != 0); \
} \
static inline void bch_set_feature_##name(struct cache_sb *sb) \
{ \
if ((sb)->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \
(sb)->version = BCACHE_SB_VERSION_CDEV_WITH_FEATURES; \
(sb)->feature_ro_compat |= \
BCH##_FEATURE_RO_COMPAT_##flagname; \
} \
static inline void bch_clear_feature_##name(struct cache_sb *sb) \
{ \
(sb)->feature_ro_compat &= \
~BCH##_FEATURE_RO_COMPAT_##flagname; \
}
#define BCH_FEATURE_INCOMPAT_FUNCS(name, flagname) \
static inline int bch_has_feature_##name(struct cache_sb *sb) \
{ \
return (((sb)->feature_incompat & \
BCH##_FEATURE_INCOMPAT_##flagname) != 0); \
} \
static inline void bch_set_feature_##name(struct cache_sb *sb) \
{ \
if ((sb)->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \
(sb)->version = BCACHE_SB_VERSION_CDEV_WITH_FEATURES; \
(sb)->feature_incompat |= \
BCH##_FEATURE_INCOMPAT_##flagname; \
} \
static inline void bch_clear_feature_##name(struct cache_sb *sb) \
{ \
(sb)->feature_incompat &= \
~BCH##_FEATURE_INCOMPAT_##flagname; \
}
BCH_FEATURE_INCOMPAT_FUNCS(obso_large_bucket, OBSO_LARGE_BUCKET);
BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LOG_LARGE_BUCKET_SIZE);
#endif
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