path: root/contrib/libs/linux-headers/linux/bcache.h

/* 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 int i)		\ 
{ return (k->ptr[i] >> offset) & ~(~0ULL << size); }			\ 
									\ 
static __inline__ void SET_##name(struct bkey *k, unsigned int 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 MAKE_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 int 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_OFFSET			(SB_SECTOR << SECTOR_SHIFT) 
#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_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			pad[8]; 
 
	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 */ 
}; 
 
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 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; 
} 
 
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; /* time overflow in y2106 */ 
			__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 */