| /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
| #ifndef _LINUX_BCACHE_H |
| #define _LINUX_BCACHE_H |
| |
| /* |
| * Bcache on disk data structures |
| */ |
| |
| #include <linux/types.h> |
| |
| #define BITMASK(name, type, field, offset, size) \ |
| static inline __u64 name(const type *k) \ |
| { return (k->field >> offset) & ~(~0ULL << size); } \ |
| \ |
| static inline void SET_##name(type *k, __u64 v) \ |
| { \ |
| k->field &= ~(~(~0ULL << size) << offset); \ |
| k->field |= (v & ~(~0ULL << size)) << offset; \ |
| } |
| |
| /* Btree keys - all units are in sectors */ |
| |
| struct bkey { |
| __u64 high; |
| __u64 low; |
| __u64 ptr[]; |
| }; |
| |
| #define KEY_FIELD(name, field, offset, size) \ |
| BITMASK(name, struct bkey, field, offset, size) |
| |
| #define PTR_FIELD(name, offset, size) \ |
| static inline __u64 name(const struct bkey *k, unsigned i) \ |
| { return (k->ptr[i] >> offset) & ~(~0ULL << size); } \ |
| \ |
| static inline void SET_##name(struct bkey *k, unsigned i, __u64 v) \ |
| { \ |
| k->ptr[i] &= ~(~(~0ULL << size) << offset); \ |
| k->ptr[i] |= (v & ~(~0ULL << size)) << offset; \ |
| } |
| |
| #define KEY_SIZE_BITS 16 |
| #define KEY_MAX_U64S 8 |
| |
| KEY_FIELD(KEY_PTRS, high, 60, 3) |
| KEY_FIELD(HEADER_SIZE, high, 58, 2) |
| KEY_FIELD(KEY_CSUM, high, 56, 2) |
| KEY_FIELD(KEY_PINNED, high, 55, 1) |
| KEY_FIELD(KEY_DIRTY, high, 36, 1) |
| |
| KEY_FIELD(KEY_SIZE, high, 20, KEY_SIZE_BITS) |
| KEY_FIELD(KEY_INODE, high, 0, 20) |
| |
| /* Next time I change the on disk format, KEY_OFFSET() won't be 64 bits */ |
| |
| static inline __u64 KEY_OFFSET(const struct bkey *k) |
| { |
| return k->low; |
| } |
| |
| static inline void SET_KEY_OFFSET(struct bkey *k, __u64 v) |
| { |
| k->low = v; |
| } |
| |
| /* |
| * The high bit being set is a relic from when we used it to do binary |
| * searches - it told you where a key started. It's not used anymore, |
| * and can probably be safely dropped. |
| */ |
| #define KEY(inode, offset, size) \ |
| ((struct bkey) { \ |
| .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \ |
| .low = (offset) \ |
| }) |
| |
| #define ZERO_KEY KEY(0, 0, 0) |
| |
| #define MAX_KEY_INODE (~(~0 << 20)) |
| #define MAX_KEY_OFFSET (~0ULL >> 1) |
| #define MAX_KEY KEY(MAX_KEY_INODE, MAX_KEY_OFFSET, 0) |
| |
| #define KEY_START(k) (KEY_OFFSET(k) - KEY_SIZE(k)) |
| #define START_KEY(k) KEY(KEY_INODE(k), KEY_START(k), 0) |
| |
| #define PTR_DEV_BITS 12 |
| |
| PTR_FIELD(PTR_DEV, 51, PTR_DEV_BITS) |
| PTR_FIELD(PTR_OFFSET, 8, 43) |
| PTR_FIELD(PTR_GEN, 0, 8) |
| |
| #define PTR_CHECK_DEV ((1 << PTR_DEV_BITS) - 1) |
| |
| #define PTR(gen, offset, dev) \ |
| ((((__u64) dev) << 51) | ((__u64) offset) << 8 | gen) |
| |
| /* Bkey utility code */ |
| |
| static inline unsigned long bkey_u64s(const struct bkey *k) |
| { |
| return (sizeof(struct bkey) / sizeof(__u64)) + KEY_PTRS(k); |
| } |
| |
| static inline unsigned long bkey_bytes(const struct bkey *k) |
| { |
| return bkey_u64s(k) * sizeof(__u64); |
| } |
| |
| #define bkey_copy(_dest, _src) memcpy(_dest, _src, bkey_bytes(_src)) |
| |
| static inline void bkey_copy_key(struct bkey *dest, const struct bkey *src) |
| { |
| SET_KEY_INODE(dest, KEY_INODE(src)); |
| SET_KEY_OFFSET(dest, KEY_OFFSET(src)); |
| } |
| |
| static inline struct bkey *bkey_next(const struct bkey *k) |
| { |
| __u64 *d = (void *) k; |
| return (struct bkey *) (d + bkey_u64s(k)); |
| } |
| |
| static inline struct bkey *bkey_idx(const struct bkey *k, unsigned nr_keys) |
| { |
| __u64 *d = (void *) k; |
| return (struct bkey *) (d + nr_keys); |
| } |
| /* Enough for a key with 6 pointers */ |
| #define BKEY_PAD 8 |
| |
| #define BKEY_PADDED(key) \ |
| union { struct bkey key; __u64 key ## _pad[BKEY_PAD]; } |
| |
| /* Superblock */ |
| |
| /* 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 |
| */ |
| #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_MAX_VERSION 4 |
| |
| #define SB_SECTOR 8 |
| #define SB_SIZE 4096 |
| #define SB_LABEL_SIZE 32 |
| #define SB_JOURNAL_BUCKETS 256U |
| /* SB_JOURNAL_BUCKETS must be divisible by BITS_PER_LONG */ |
| #define MAX_CACHES_PER_SET 8 |
| |
| #define BDEV_DATA_START_DEFAULT 16 /* sectors */ |
| |
| struct cache_sb { |
| __u64 csum; |
| __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 pad[8]; |
| |
| union { |
| struct { |
| /* Cache devices */ |
| __u64 nbuckets; /* device size */ |
| |
| __u16 block_size; /* sectors */ |
| __u16 bucket_size; /* sectors */ |
| |
| __u16 nr_in_set; |
| __u16 nr_this_dev; |
| }; |
| 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_t */ |
| |
| __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; |
| } |
| |
| 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 |
| |
| /* |
| * Magic numbers |
| * |
| * The various other data structures have their own magic numbers, which are |
| * xored with the first part of the cache set's UUID |
| */ |
| |
| #define JSET_MAGIC 0x245235c1a3625032ULL |
| #define PSET_MAGIC 0x6750e15f87337f91ULL |
| #define BSET_MAGIC 0x90135c78b99e07f5ULL |
| |
| static inline __u64 jset_magic(struct cache_sb *sb) |
| { |
| return sb->set_magic ^ JSET_MAGIC; |
| } |
| |
| static inline __u64 pset_magic(struct cache_sb *sb) |
| { |
| return sb->set_magic ^ PSET_MAGIC; |
| } |
| |
| static inline __u64 bset_magic(struct cache_sb *sb) |
| { |
| return sb->set_magic ^ BSET_MAGIC; |
| } |
| |
| /* |
| * Journal |
| * |
| * On disk format for a journal entry: |
| * seq is monotonically increasing; every journal entry has its own unique |
| * sequence number. |
| * |
| * last_seq is the oldest journal entry that still has keys the btree hasn't |
| * flushed to disk yet. |
| * |
| * version is for on disk format changes. |
| */ |
| |
| #define BCACHE_JSET_VERSION_UUIDv1 1 |
| #define BCACHE_JSET_VERSION_UUID 1 /* Always latest UUID format */ |
| #define BCACHE_JSET_VERSION 1 |
| |
| struct jset { |
| __u64 csum; |
| __u64 magic; |
| __u64 seq; |
| __u32 version; |
| __u32 keys; |
| |
| __u64 last_seq; |
| |
| BKEY_PADDED(uuid_bucket); |
| BKEY_PADDED(btree_root); |
| __u16 btree_level; |
| __u16 pad[3]; |
| |
| __u64 prio_bucket[MAX_CACHES_PER_SET]; |
| |
| union { |
| struct bkey start[0]; |
| __u64 d[0]; |
| }; |
| }; |
| |
| /* Bucket prios/gens */ |
| |
| struct prio_set { |
| __u64 csum; |
| __u64 magic; |
| __u64 seq; |
| __u32 version; |
| __u32 pad; |
| |
| __u64 next_bucket; |
| |
| struct bucket_disk { |
| __u16 prio; |
| __u8 gen; |
| } __attribute((packed)) data[]; |
| }; |
| |
| /* UUIDS - per backing device/flash only volume metadata */ |
| |
| struct uuid_entry { |
| union { |
| struct { |
| __u8 uuid[16]; |
| __u8 label[32]; |
| __u32 first_reg; |
| __u32 last_reg; |
| __u32 invalidated; |
| |
| __u32 flags; |
| /* Size of flash only volumes */ |
| __u64 sectors; |
| }; |
| |
| __u8 pad[128]; |
| }; |
| }; |
| |
| BITMASK(UUID_FLASH_ONLY, struct uuid_entry, flags, 0, 1); |
| |
| /* Btree nodes */ |
| |
| /* Version 1: Seed pointer into btree node checksum |
| */ |
| #define BCACHE_BSET_CSUM 1 |
| #define BCACHE_BSET_VERSION 1 |
| |
| /* |
| * Btree nodes |
| * |
| * On disk a btree node is a list/log of these; within each set the keys are |
| * sorted |
| */ |
| struct bset { |
| __u64 csum; |
| __u64 magic; |
| __u64 seq; |
| __u32 version; |
| __u32 keys; |
| |
| union { |
| struct bkey start[0]; |
| __u64 d[0]; |
| }; |
| }; |
| |
| /* OBSOLETE */ |
| |
| /* UUIDS - per backing device/flash only volume metadata */ |
| |
| struct uuid_entry_v0 { |
| __u8 uuid[16]; |
| __u8 label[32]; |
| __u32 first_reg; |
| __u32 last_reg; |
| __u32 invalidated; |
| __u32 pad; |
| }; |
| |
| #endif /* _LINUX_BCACHE_H */ |