bcachefs-tools/bcache.h
2012-01-18 16:05:32 -08:00

78 lines
1.8 KiB
C

#ifndef _BCACHE_H
#define _BCACHE_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 1: Backing dev
* Version 2: Seed pointer into btree node checksum
* Version 3: Backing dev superblock has offset of start of data
*/
#define BCACHE_SB_BDEV_VERSION 3
#define BCACHE_SB_MAX_VERSION 3
#define SB_SECTOR 8
#define SB_LABEL_SIZE 32
struct cache_sb {
uint64_t csum;
uint64_t offset; /* sector where this sb was written */
uint64_t version;
#define CACHE_BACKING_DEV 1
uint8_t magic[16];
uint8_t uuid[16];
union {
uint8_t set_uuid[16];
uint64_t set_magic;
};
uint8_t label[SB_LABEL_SIZE];
uint64_t flags;
uint64_t seq;
uint64_t pad[8];
uint64_t nbuckets; /* device size */
uint16_t block_size; /* sectors */
uint16_t bucket_size; /* sectors */
uint16_t nr_in_set;
uint16_t nr_this_dev;
uint32_t last_mount; /* time_t */
uint16_t first_bucket;
uint16_t keys; /* number of journal buckets */
uint64_t d[]; /* journal buckets */
};
BITMASK(SB_BDEV, struct cache_sb, version, 0, 1);
BITMASK(BDEV_WRITEBACK, struct cache_sb, flags, 0, 1);
BITMASK(CACHE_DISCARD, struct cache_sb, flags, 1, 1);
BITMASK(CACHE_REPLACEMENT, struct cache_sb, flags, 2, 3);
inline 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))
#endif