[mirror_ubuntu-bionic-kernel.git] / include / uapi / linux / bcache.h

#ifndef _LINUX_BCACHE_H
#define _LINUX_BCACHE_H

/*
 * Bcache on disk data structures
 */

#include <asm/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 */
Commit	Line	Data
81ab4190 KO	1	#ifndef _LINUX_BCACHE_H
	2	#define _LINUX_BCACHE_H
	3
	4	/*
	5	* Bcache on disk data structures
	6	*/
	7
	8	#include <asm/types.h>
	9
	10	#define BITMASK(name, type, field, offset, size) \
	11	static inline __u64 name(const type *k) \
	12	{ return (k->field >> offset) & ~(~0ULL << size); } \
	13	\
	14	static inline void SET_##name(type *k, __u64 v) \
	15	{ \
	16	k->field &= ~(~(~0ULL << size) << offset); \
	17	k->field \|= (v & ~(~0ULL << size)) << offset; \
	18	}
	19
	20	/* Btree keys - all units are in sectors */
	21
	22	struct bkey {
	23	__u64 high;
	24	__u64 low;
	25	__u64 ptr[];
	26	};
	27
	28	#define KEY_FIELD(name, field, offset, size) \
	29	BITMASK(name, struct bkey, field, offset, size)
	30
	31	#define PTR_FIELD(name, offset, size) \
	32	static inline __u64 name(const struct bkey *k, unsigned i) \
	33	{ return (k->ptr[i] >> offset) & ~(~0ULL << size); } \
	34	\
	35	static inline void SET_##name(struct bkey *k, unsigned i, __u64 v) \
	36	{ \
	37	k->ptr[i] &= ~(~(~0ULL << size) << offset); \
	38	k->ptr[i] \|= (v & ~(~0ULL << size)) << offset; \
	39	}
	40
	41	#define KEY_SIZE_BITS 16
59158fde	42	#define KEY_MAX_U64S 8
81ab4190 KO	43
	44	KEY_FIELD(KEY_PTRS, high, 60, 3)
	45	KEY_FIELD(HEADER_SIZE, high, 58, 2)
	46	KEY_FIELD(KEY_CSUM, high, 56, 2)
	47	KEY_FIELD(KEY_PINNED, high, 55, 1)
	48	KEY_FIELD(KEY_DIRTY, high, 36, 1)
	49
	50	KEY_FIELD(KEY_SIZE, high, 20, KEY_SIZE_BITS)
	51	KEY_FIELD(KEY_INODE, high, 0, 20)
	52
	53	/* Next time I change the on disk format, KEY_OFFSET() won't be 64 bits */
	54
	55	static inline __u64 KEY_OFFSET(const struct bkey *k)
	56	{
	57	return k->low;
	58	}
	59
	60	static inline void SET_KEY_OFFSET(struct bkey *k, __u64 v)
	61	{
	62	k->low = v;
	63	}
	64
	65	/*
	66	* The high bit being set is a relic from when we used it to do binary
	67	* searches - it told you where a key started. It's not used anymore,
	68	* and can probably be safely dropped.
	69	*/
	70	#define KEY(inode, offset, size) \
	71	((struct bkey) { \
	72	.high = (1ULL << 63) \| ((__u64) (size) << 20) \| (inode), \
	73	.low = (offset) \
	74	})
	75
	76	#define ZERO_KEY KEY(0, 0, 0)
	77
	78	#define MAX_KEY_INODE (~(~0 << 20))
	79	#define MAX_KEY_OFFSET (~0ULL >> 1)
	80	#define MAX_KEY KEY(MAX_KEY_INODE, MAX_KEY_OFFSET, 0)
	81
	82	#define KEY_START(k) (KEY_OFFSET(k) - KEY_SIZE(k))
	83	#define START_KEY(k) KEY(KEY_INODE(k), KEY_START(k), 0)
	84
	85	#define PTR_DEV_BITS 12
	86
	87	PTR_FIELD(PTR_DEV, 51, PTR_DEV_BITS)
	88	PTR_FIELD(PTR_OFFSET, 8, 43)
	89	PTR_FIELD(PTR_GEN, 0, 8)
	90
	91	#define PTR_CHECK_DEV ((1 << PTR_DEV_BITS) - 1)
	92
	93	#define PTR(gen, offset, dev) \
	94	((((__u64) dev) << 51) \| ((__u64) offset) << 8 \| gen)
	95
	96	/* Bkey utility code */
	97
	98	static inline unsigned long bkey_u64s(const struct bkey *k)
	99	{
	100	return (sizeof(struct bkey) / sizeof(__u64)) + KEY_PTRS(k);
	101	}
	102
	103	static inline unsigned long bkey_bytes(const struct bkey *k)
	104	{
	105	return bkey_u64s(k) * sizeof(__u64);
	106	}
107
108	#define bkey_copy(_dest, _src) memcpy(_dest, _src, bkey_bytes(_src))
109
110	static inline void bkey_copy_key(struct bkey dest, const struct bkey src)
111	{
112	SET_KEY_INODE(dest, KEY_INODE(src));
113	SET_KEY_OFFSET(dest, KEY_OFFSET(src));
114	}
115
116	static inline struct bkey bkey_next(const struct bkey k)
117	{
118	__u64 d = (void ) k;
119	return (struct bkey *) (d + bkey_u64s(k));
120	}
121
fafff81c	122	static inline struct bkey bkey_idx(const struct bkey k, unsigned nr_keys)
81ab4190 KO	123	{
	124	__u64 d = (void ) k;
	125	return (struct bkey *) (d + nr_keys);
	126	}
	127	/* Enough for a key with 6 pointers */
	128	#define BKEY_PAD 8
	129
	130	#define BKEY_PADDED(key) \
	131	union { struct bkey key; __u64 key ## _pad[BKEY_PAD]; }
	132
	133	/* Superblock */
	134
	135	/* Version 0: Cache device
	136	* Version 1: Backing device
	137	* Version 2: Seed pointer into btree node checksum
	138	* Version 3: Cache device with new UUID format
	139	* Version 4: Backing device with data offset
	140	*/
	141	#define BCACHE_SB_VERSION_CDEV 0
	142	#define BCACHE_SB_VERSION_BDEV 1
	143	#define BCACHE_SB_VERSION_CDEV_WITH_UUID 3
	144	#define BCACHE_SB_VERSION_BDEV_WITH_OFFSET 4
	145	#define BCACHE_SB_MAX_VERSION 4
	146
	147	#define SB_SECTOR 8
	148	#define SB_SIZE 4096
	149	#define SB_LABEL_SIZE 32
	150	#define SB_JOURNAL_BUCKETS 256U
	151	/* SB_JOURNAL_BUCKETS must be divisible by BITS_PER_LONG */
	152	#define MAX_CACHES_PER_SET 8
	153
	154	#define BDEV_DATA_START_DEFAULT 16 /* sectors */
	155
	156	struct cache_sb {
	157	__u64 csum;
	158	__u64 offset; /* sector where this sb was written */
	159	__u64 version;
	160
	161	__u8 magic[16];
	162
	163	__u8 uuid[16];
	164	union {
	165	__u8 set_uuid[16];
	166	__u64 set_magic;
	167	};
	168	__u8 label[SB_LABEL_SIZE];
	169
	170	__u64 flags;
	171	__u64 seq;
	172	__u64 pad[8];
	173
	174	union {
	175	struct {
	176	/* Cache devices */
	177	__u64 nbuckets; /* device size */
	178
	179	__u16 block_size; /* sectors */
	180	__u16 bucket_size; /* sectors */
	181
	182	__u16 nr_in_set;
	183	__u16 nr_this_dev;
	184	};
	185	struct {
	186	/* Backing devices */
187	__u64 data_offset;
188
189	/*
190	* block_size from the cache device section is still used by
191	* backing devices, so don't add anything here until we fix
192	* things to not need it for backing devices anymore
193	*/
194	};
195	};
196
197	__u32 last_mount; /* time_t */
198
199	__u16 first_bucket;
200	union {
201	__u16 njournal_buckets;
202	__u16 keys;
203	};
204	__u64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
205	};
206
207	static inline _Bool SB_IS_BDEV(const struct cache_sb *sb)
208	{
209	return sb->version == BCACHE_SB_VERSION_BDEV
210	\|\| sb->version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET;
211	}
212
213	BITMASK(CACHE_SYNC, struct cache_sb, flags, 0, 1);
214	BITMASK(CACHE_DISCARD, struct cache_sb, flags, 1, 1);
215	BITMASK(CACHE_REPLACEMENT, struct cache_sb, flags, 2, 3);
216	#define CACHE_REPLACEMENT_LRU 0U
217	#define CACHE_REPLACEMENT_FIFO 1U
218	#define CACHE_REPLACEMENT_RANDOM 2U
219
220	BITMASK(BDEV_CACHE_MODE, struct cache_sb, flags, 0, 4);
221	#define CACHE_MODE_WRITETHROUGH 0U
222	#define CACHE_MODE_WRITEBACK 1U
223	#define CACHE_MODE_WRITEAROUND 2U
224	#define CACHE_MODE_NONE 3U
225	BITMASK(BDEV_STATE, struct cache_sb, flags, 61, 2);
226	#define BDEV_STATE_NONE 0U
227	#define BDEV_STATE_CLEAN 1U
228	#define BDEV_STATE_DIRTY 2U
229	#define BDEV_STATE_STALE 3U
230
231	/*
232	* Magic numbers
233	*
234	* The various other data structures have their own magic numbers, which are
235	* xored with the first part of the cache set's UUID
236	*/
237
238	#define JSET_MAGIC 0x245235c1a3625032ULL
239	#define PSET_MAGIC 0x6750e15f87337f91ULL
240	#define BSET_MAGIC 0x90135c78b99e07f5ULL
241
242	static inline __u64 jset_magic(struct cache_sb *sb)
243	{
244	return sb->set_magic ^ JSET_MAGIC;
245	}
246
247	static inline __u64 pset_magic(struct cache_sb *sb)
248	{
249	return sb->set_magic ^ PSET_MAGIC;
250	}
251
252	static inline __u64 bset_magic(struct cache_sb *sb)
253	{
254	return sb->set_magic ^ BSET_MAGIC;
255	}
256
257	/*
258	* Journal
259	*
260	* On disk format for a journal entry:
261	* seq is monotonically increasing; every journal entry has its own unique
262	* sequence number.
263	*
264	* last_seq is the oldest journal entry that still has keys the btree hasn't
265	* flushed to disk yet.
266	*
267	* version is for on disk format changes.
268	*/
269
270	#define BCACHE_JSET_VERSION_UUIDv1 1
271	#define BCACHE_JSET_VERSION_UUID 1 /* Always latest UUID format */
272	#define BCACHE_JSET_VERSION 1
273
274	struct jset {
275	__u64 csum;
276	__u64 magic;
277	__u64 seq;
278	__u32 version;
279	__u32 keys;
280
281	__u64 last_seq;
282
283	BKEY_PADDED(uuid_bucket);
284	BKEY_PADDED(btree_root);
285	__u16 btree_level;
286	__u16 pad[3];
287
288	__u64 prio_bucket[MAX_CACHES_PER_SET];
289
290	union {
291	struct bkey start[0];
292	__u64 d[0];
293	};
294	};
295
296	/* Bucket prios/gens */
297
298	struct prio_set {
299	__u64 csum;
300	__u64 magic;
301	__u64 seq;
302	__u32 version;
303	__u32 pad;
304
305	__u64 next_bucket;
306
307	struct bucket_disk {
308	__u16 prio;
309	__u8 gen;
310	} __attribute((packed)) data[];
311	};
312
313	/* UUIDS - per backing device/flash only volume metadata */
314
315	struct uuid_entry {
316	union {
317	struct {
318	__u8 uuid[16];
319	__u8 label[32];
320	__u32 first_reg;
321	__u32 last_reg;
322	__u32 invalidated;
323
324	__u32 flags;
325	/* Size of flash only volumes */
326	__u64 sectors;
327	};
328
329	__u8 pad[128];
330	};
331	};
332
333	BITMASK(UUID_FLASH_ONLY, struct uuid_entry, flags, 0, 1);
334
335	/* Btree nodes */
336
337	/* Version 1: Seed pointer into btree node checksum
338	*/
339	#define BCACHE_BSET_CSUM 1
340	#define BCACHE_BSET_VERSION 1
341
342	/*
343	* Btree nodes
344	*
345	* On disk a btree node is a list/log of these; within each set the keys are
346	* sorted
347	*/
348	struct bset {
349	__u64 csum;
350	__u64 magic;
351	__u64 seq;
352	__u32 version;
353	__u32 keys;
354
355	union {
356	struct bkey start[0];
357	__u64 d[0];
358	};
359	};
360
361	/* OBSOLETE */
362
363	/* UUIDS - per backing device/flash only volume metadata */
364
365	struct uuid_entry_v0 {
366	__u8 uuid[16];
367	__u8 label[32];
368	__u32 first_reg;
369	__u32 last_reg;
370	__u32 invalidated;
371	__u32 pad;
372	};
373
374	#endif /* _LINUX_BCACHE_H */