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bcachefs_format.h
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bcachefs_format.h
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_FORMAT_H
#define _BCACHEFS_FORMAT_H
/*
* bcachefs on disk data structures
*
* OVERVIEW:
*
* There are three main types of on disk data structures in bcachefs (this is
* reduced from 5 in bcache)
*
* - superblock
* - journal
* - btree
*
* The btree is the primary structure; most metadata exists as keys in the
* various btrees. There are only a small number of btrees, they're not
* sharded - we have one btree for extents, another for inodes, et cetera.
*
* SUPERBLOCK:
*
* The superblock contains the location of the journal, the list of devices in
* the filesystem, and in general any metadata we need in order to decide
* whether we can start a filesystem or prior to reading the journal/btree
* roots.
*
* The superblock is extensible, and most of the contents of the superblock are
* in variable length, type tagged fields; see struct bch_sb_field.
*
* Backup superblocks do not reside in a fixed location; also, superblocks do
* not have a fixed size. To locate backup superblocks we have struct
* bch_sb_layout; we store a copy of this inside every superblock, and also
* before the first superblock.
*
* JOURNAL:
*
* The journal primarily records btree updates in the order they occurred;
* journal replay consists of just iterating over all the keys in the open
* journal entries and re-inserting them into the btrees.
*
* The journal also contains entry types for the btree roots, and blacklisted
* journal sequence numbers (see journal_seq_blacklist.c).
*
* BTREE:
*
* bcachefs btrees are copy on write b+ trees, where nodes are big (typically
* 128k-256k) and log structured. We use struct btree_node for writing the first
* entry in a given node (offset 0), and struct btree_node_entry for all
* subsequent writes.
*
* After the header, btree node entries contain a list of keys in sorted order.
* Values are stored inline with the keys; since values are variable length (and
* keys effectively are variable length too, due to packing) we can't do random
* access without building up additional in memory tables in the btree node read
* path.
*
* BTREE KEYS (struct bkey):
*
* The various btrees share a common format for the key - so as to avoid
* switching in fastpath lookup/comparison code - but define their own
* structures for the key values.
*
* The size of a key/value pair is stored as a u8 in units of u64s, so the max
* size is just under 2k. The common part also contains a type tag for the
* value, and a format field indicating whether the key is packed or not (and
* also meant to allow adding new key fields in the future, if desired).
*
* bkeys, when stored within a btree node, may also be packed. In that case, the
* bkey_format in that node is used to unpack it. Packed bkeys mean that we can
* be generous with field sizes in the common part of the key format (64 bit
* inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost.
*/
#include <asm/types.h>
#include <asm/byteorder.h>
#include <linux/kernel.h>
#include <linux/uuid.h>
#include "vstructs.h"
#ifdef __KERNEL__
typedef uuid_t __uuid_t;
#endif
#define BITMASK(name, type, field, offset, end) \
static const __maybe_unused unsigned name##_OFFSET = offset; \
static const __maybe_unused unsigned name##_BITS = (end - offset); \
\
static inline __u64 name(const type *k) \
{ \
return (k->field >> offset) & ~(~0ULL << (end - offset)); \
} \
\
static inline void SET_##name(type *k, __u64 v) \
{ \
k->field &= ~(~(~0ULL << (end - offset)) << offset); \
k->field |= (v & ~(~0ULL << (end - offset))) << offset; \
}
#define LE_BITMASK(_bits, name, type, field, offset, end) \
static const __maybe_unused unsigned name##_OFFSET = offset; \
static const __maybe_unused unsigned name##_BITS = (end - offset); \
static const __maybe_unused __u##_bits name##_MAX = (1ULL << (end - offset)) - 1;\
\
static inline __u64 name(const type *k) \
{ \
return (__le##_bits##_to_cpu(k->field) >> offset) & \
~(~0ULL << (end - offset)); \
} \
\
static inline void SET_##name(type *k, __u64 v) \
{ \
__u##_bits new = __le##_bits##_to_cpu(k->field); \
\
new &= ~(~(~0ULL << (end - offset)) << offset); \
new |= (v & ~(~0ULL << (end - offset))) << offset; \
k->field = __cpu_to_le##_bits(new); \
}
#define LE16_BITMASK(n, t, f, o, e) LE_BITMASK(16, n, t, f, o, e)
#define LE32_BITMASK(n, t, f, o, e) LE_BITMASK(32, n, t, f, o, e)
#define LE64_BITMASK(n, t, f, o, e) LE_BITMASK(64, n, t, f, o, e)
struct bkey_format {
__u8 key_u64s;
__u8 nr_fields;
/* One unused slot for now: */
__u8 bits_per_field[6];
__le64 field_offset[6];
};
/* Btree keys - all units are in sectors */
struct bpos {
/*
* Word order matches machine byte order - btree code treats a bpos as a
* single large integer, for search/comparison purposes
*
* Note that wherever a bpos is embedded in another on disk data
* structure, it has to be byte swabbed when reading in metadata that
* wasn't written in native endian order:
*/
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
__u32 snapshot;
__u64 offset;
__u64 inode;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
__u64 inode;
__u64 offset; /* Points to end of extent - sectors */
__u32 snapshot;
#else
#error edit for your odd byteorder.
#endif
} __packed
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
__aligned(4)
#endif
;
#define KEY_INODE_MAX ((__u64)~0ULL)
#define KEY_OFFSET_MAX ((__u64)~0ULL)
#define KEY_SNAPSHOT_MAX ((__u32)~0U)
#define KEY_SIZE_MAX ((__u32)~0U)
static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
{
return (struct bpos) {
.inode = inode,
.offset = offset,
.snapshot = snapshot,
};
}
#define POS_MIN SPOS(0, 0, 0)
#define POS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
#define SPOS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
#define POS(_inode, _offset) SPOS(_inode, _offset, 0)
/* Empty placeholder struct, for container_of() */
struct bch_val {
__u64 __nothing[0];
};
struct bversion {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
__u64 lo;
__u32 hi;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
__u32 hi;
__u64 lo;
#endif
} __packed __aligned(4);
struct bkey {
/* Size of combined key and value, in u64s */
__u8 u64s;
/* Format of key (0 for format local to btree node) */
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 format:7,
needs_whiteout:1;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u8 needs_whiteout:1,
format:7;
#else
#error edit for your odd byteorder.
#endif
/* Type of the value */
__u8 type;
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
__u8 pad[1];
struct bversion version;
__u32 size; /* extent size, in sectors */
struct bpos p;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
struct bpos p;
__u32 size; /* extent size, in sectors */
struct bversion version;
__u8 pad[1];
#endif
} __packed __aligned(8);
struct bkey_packed {
__u64 _data[0];
/* Size of combined key and value, in u64s */
__u8 u64s;
/* Format of key (0 for format local to btree node) */
/*
* XXX: next incompat on disk format change, switch format and
* needs_whiteout - bkey_packed() will be cheaper if format is the high
* bits of the bitfield
*/
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 format:7,
needs_whiteout:1;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u8 needs_whiteout:1,
format:7;
#endif
/* Type of the value */
__u8 type;
__u8 key_start[0];
/*
* We copy bkeys with struct assignment in various places, and while
* that shouldn't be done with packed bkeys we can't disallow it in C,
* and it's legal to cast a bkey to a bkey_packed - so padding it out
* to the same size as struct bkey should hopefully be safest.
*/
__u8 pad[sizeof(struct bkey) - 3];
} __packed __aligned(8);
typedef struct {
__le64 lo;
__le64 hi;
} bch_le128;
#define BKEY_U64s (sizeof(struct bkey) / sizeof(__u64))
#define BKEY_U64s_MAX U8_MAX
#define BKEY_VAL_U64s_MAX (BKEY_U64s_MAX - BKEY_U64s)
#define KEY_PACKED_BITS_START 24
#define KEY_FORMAT_LOCAL_BTREE 0
#define KEY_FORMAT_CURRENT 1
enum bch_bkey_fields {
BKEY_FIELD_INODE,
BKEY_FIELD_OFFSET,
BKEY_FIELD_SNAPSHOT,
BKEY_FIELD_SIZE,
BKEY_FIELD_VERSION_HI,
BKEY_FIELD_VERSION_LO,
BKEY_NR_FIELDS,
};
#define bkey_format_field(name, field) \
[BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
#define BKEY_FORMAT_CURRENT \
((struct bkey_format) { \
.key_u64s = BKEY_U64s, \
.nr_fields = BKEY_NR_FIELDS, \
.bits_per_field = { \
bkey_format_field(INODE, p.inode), \
bkey_format_field(OFFSET, p.offset), \
bkey_format_field(SNAPSHOT, p.snapshot), \
bkey_format_field(SIZE, size), \
bkey_format_field(VERSION_HI, version.hi), \
bkey_format_field(VERSION_LO, version.lo), \
}, \
})
/* bkey with inline value */
struct bkey_i {
__u64 _data[0];
struct bkey k;
struct bch_val v;
};
#define POS_KEY(_pos) \
((struct bkey) { \
.u64s = BKEY_U64s, \
.format = KEY_FORMAT_CURRENT, \
.p = _pos, \
})
#define KEY(_inode, _offset, _size) \
((struct bkey) { \
.u64s = BKEY_U64s, \
.format = KEY_FORMAT_CURRENT, \
.p = POS(_inode, _offset), \
.size = _size, \
})
static inline void bkey_init(struct bkey *k)
{
*k = KEY(0, 0, 0);
}
#define bkey_bytes(_k) ((_k)->u64s * sizeof(__u64))
#define __BKEY_PADDED(key, pad) \
struct bkey_i key; __u64 key ## _pad[pad]
/*
* - DELETED keys are used internally to mark keys that should be ignored but
* override keys in composition order. Their version number is ignored.
*
* - DISCARDED keys indicate that the data is all 0s because it has been
* discarded. DISCARDs may have a version; if the version is nonzero the key
* will be persistent, otherwise the key will be dropped whenever the btree
* node is rewritten (like DELETED keys).
*
* - ERROR: any read of the data returns a read error, as the data was lost due
* to a failing device. Like DISCARDED keys, they can be removed (overridden)
* by new writes or cluster-wide GC. Node repair can also overwrite them with
* the same or a more recent version number, but not with an older version
* number.
*
* - WHITEOUT: for hash table btrees
*/
#define BCH_BKEY_TYPES() \
x(deleted, 0) \
x(whiteout, 1) \
x(error, 2) \
x(cookie, 3) \
x(hash_whiteout, 4) \
x(btree_ptr, 5) \
x(extent, 6) \
x(reservation, 7) \
x(inode, 8) \
x(inode_generation, 9) \
x(dirent, 10) \
x(xattr, 11) \
x(alloc, 12) \
x(quota, 13) \
x(stripe, 14) \
x(reflink_p, 15) \
x(reflink_v, 16) \
x(inline_data, 17) \
x(btree_ptr_v2, 18) \
x(indirect_inline_data, 19) \
x(alloc_v2, 20) \
x(subvolume, 21) \
x(snapshot, 22) \
x(inode_v2, 23) \
x(alloc_v3, 24) \
x(set, 25) \
x(lru, 26) \
x(alloc_v4, 27) \
x(backpointer, 28) \
x(inode_v3, 29) \
x(bucket_gens, 30) \
x(snapshot_tree, 31) \
x(logged_op_truncate, 32) \
x(logged_op_finsert, 33)
enum bch_bkey_type {
#define x(name, nr) KEY_TYPE_##name = nr,
BCH_BKEY_TYPES()
#undef x
KEY_TYPE_MAX,
};
struct bch_deleted {
struct bch_val v;
};
struct bch_whiteout {
struct bch_val v;
};
struct bch_error {
struct bch_val v;
};
struct bch_cookie {
struct bch_val v;
__le64 cookie;
};
struct bch_hash_whiteout {
struct bch_val v;
};
struct bch_set {
struct bch_val v;
};
/* 128 bits, sufficient for cryptographic MACs: */
struct bch_csum {
__le64 lo;
__le64 hi;
} __packed __aligned(8);
struct bch_backpointer {
struct bch_val v;
__u8 btree_id;
__u8 level;
__u8 data_type;
__u64 bucket_offset:40;
__u32 bucket_len;
struct bpos pos;
} __packed __aligned(8);
/* LRU btree: */
struct bch_lru {
struct bch_val v;
__le64 idx;
} __packed __aligned(8);
#define LRU_ID_STRIPES (1U << 16)
/* Optional/variable size superblock sections: */
struct bch_sb_field {
__u64 _data[0];
__le32 u64s;
__le32 type;
};
#define BCH_SB_FIELDS() \
x(journal, 0) \
x(members_v1, 1) \
x(crypt, 2) \
x(replicas_v0, 3) \
x(quota, 4) \
x(disk_groups, 5) \
x(clean, 6) \
x(replicas, 7) \
x(journal_seq_blacklist, 8) \
x(journal_v2, 9) \
x(counters, 10) \
x(members_v2, 11) \
x(errors, 12) \
x(ext, 13) \
x(downgrade, 14)
#include "alloc_background_format.h"
#include "extents_format.h"
#include "reflink_format.h"
#include "ec_format.h"
#include "inode_format.h"
#include "dirent_format.h"
#include "xattr_format.h"
#include "quota_format.h"
#include "logged_ops_format.h"
#include "snapshot_format.h"
#include "subvolume_format.h"
#include "sb-counters_format.h"
enum bch_sb_field_type {
#define x(f, nr) BCH_SB_FIELD_##f = nr,
BCH_SB_FIELDS()
#undef x
BCH_SB_FIELD_NR
};
/*
* Most superblock fields are replicated in all device's superblocks - a few are
* not:
*/
#define BCH_SINGLE_DEVICE_SB_FIELDS \
((1U << BCH_SB_FIELD_journal)| \
(1U << BCH_SB_FIELD_journal_v2))
/* BCH_SB_FIELD_journal: */
struct bch_sb_field_journal {
struct bch_sb_field field;
__le64 buckets[];
};
struct bch_sb_field_journal_v2 {
struct bch_sb_field field;
struct bch_sb_field_journal_v2_entry {
__le64 start;
__le64 nr;
} d[];
};
/* BCH_SB_FIELD_members_v1: */
#define BCH_MIN_NR_NBUCKETS (1 << 6)
#define BCH_IOPS_MEASUREMENTS() \
x(seqread, 0) \
x(seqwrite, 1) \
x(randread, 2) \
x(randwrite, 3)
enum bch_iops_measurement {
#define x(t, n) BCH_IOPS_##t = n,
BCH_IOPS_MEASUREMENTS()
#undef x
BCH_IOPS_NR
};
#define BCH_MEMBER_ERROR_TYPES() \
x(read, 0) \
x(write, 1) \
x(checksum, 2)
enum bch_member_error_type {
#define x(t, n) BCH_MEMBER_ERROR_##t = n,
BCH_MEMBER_ERROR_TYPES()
#undef x
BCH_MEMBER_ERROR_NR
};
struct bch_member {
__uuid_t uuid;
__le64 nbuckets; /* device size */
__le16 first_bucket; /* index of first bucket used */
__le16 bucket_size; /* sectors */
__le32 pad;
__le64 last_mount; /* time_t */
__le64 flags;
__le32 iops[4];
__le64 errors[BCH_MEMBER_ERROR_NR];
__le64 errors_at_reset[BCH_MEMBER_ERROR_NR];
__le64 errors_reset_time;
__le64 seq;
};
#define BCH_MEMBER_V1_BYTES 56
LE64_BITMASK(BCH_MEMBER_STATE, struct bch_member, flags, 0, 4)
/* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
LE64_BITMASK(BCH_MEMBER_DISCARD, struct bch_member, flags, 14, 15)
LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED, struct bch_member, flags, 15, 20)
LE64_BITMASK(BCH_MEMBER_GROUP, struct bch_member, flags, 20, 28)
LE64_BITMASK(BCH_MEMBER_DURABILITY, struct bch_member, flags, 28, 30)
LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
struct bch_member, flags, 30, 31)
#if 0
LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS, struct bch_member, flags[1], 0, 20);
LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
#endif
#define BCH_MEMBER_STATES() \
x(rw, 0) \
x(ro, 1) \
x(failed, 2) \
x(spare, 3)
enum bch_member_state {
#define x(t, n) BCH_MEMBER_STATE_##t = n,
BCH_MEMBER_STATES()
#undef x
BCH_MEMBER_STATE_NR
};
struct bch_sb_field_members_v1 {
struct bch_sb_field field;
struct bch_member _members[]; //Members are now variable size
};
struct bch_sb_field_members_v2 {
struct bch_sb_field field;
__le16 member_bytes; //size of single member entry
u8 pad[6];
struct bch_member _members[];
};
/* BCH_SB_FIELD_crypt: */
struct nonce {
__le32 d[4];
};
struct bch_key {
__le64 key[4];
};
#define BCH_KEY_MAGIC \
(((__u64) 'b' << 0)|((__u64) 'c' << 8)| \
((__u64) 'h' << 16)|((__u64) '*' << 24)| \
((__u64) '*' << 32)|((__u64) 'k' << 40)| \
((__u64) 'e' << 48)|((__u64) 'y' << 56))
struct bch_encrypted_key {
__le64 magic;
struct bch_key key;
};
/*
* If this field is present in the superblock, it stores an encryption key which
* is used encrypt all other data/metadata. The key will normally be encrypted
* with the key userspace provides, but if encryption has been turned off we'll
* just store the master key unencrypted in the superblock so we can access the
* previously encrypted data.
*/
struct bch_sb_field_crypt {
struct bch_sb_field field;
__le64 flags;
__le64 kdf_flags;
struct bch_encrypted_key key;
};
LE64_BITMASK(BCH_CRYPT_KDF_TYPE, struct bch_sb_field_crypt, flags, 0, 4);
enum bch_kdf_types {
BCH_KDF_SCRYPT = 0,
BCH_KDF_NR = 1,
};
/* stored as base 2 log of scrypt params: */
LE64_BITMASK(BCH_KDF_SCRYPT_N, struct bch_sb_field_crypt, kdf_flags, 0, 16);
LE64_BITMASK(BCH_KDF_SCRYPT_R, struct bch_sb_field_crypt, kdf_flags, 16, 32);
LE64_BITMASK(BCH_KDF_SCRYPT_P, struct bch_sb_field_crypt, kdf_flags, 32, 48);
/* BCH_SB_FIELD_replicas: */
#define BCH_DATA_TYPES() \
x(free, 0) \
x(sb, 1) \
x(journal, 2) \
x(btree, 3) \
x(user, 4) \
x(cached, 5) \
x(parity, 6) \
x(stripe, 7) \
x(need_gc_gens, 8) \
x(need_discard, 9)
enum bch_data_type {
#define x(t, n) BCH_DATA_##t,
BCH_DATA_TYPES()
#undef x
BCH_DATA_NR
};
static inline bool data_type_is_empty(enum bch_data_type type)
{
switch (type) {
case BCH_DATA_free:
case BCH_DATA_need_gc_gens:
case BCH_DATA_need_discard:
return true;
default:
return false;
}
}
static inline bool data_type_is_hidden(enum bch_data_type type)
{
switch (type) {
case BCH_DATA_sb:
case BCH_DATA_journal:
return true;
default:
return false;
}
}
struct bch_replicas_entry_v0 {
__u8 data_type;
__u8 nr_devs;
__u8 devs[];
} __packed;
struct bch_sb_field_replicas_v0 {
struct bch_sb_field field;
struct bch_replicas_entry_v0 entries[];
} __packed __aligned(8);
struct bch_replicas_entry_v1 {
__u8 data_type;
__u8 nr_devs;
__u8 nr_required;
__u8 devs[];
} __packed;
#define replicas_entry_bytes(_i) \
(offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
struct bch_sb_field_replicas {
struct bch_sb_field field;
struct bch_replicas_entry_v1 entries[];
} __packed __aligned(8);
/* BCH_SB_FIELD_disk_groups: */
#define BCH_SB_LABEL_SIZE 32
struct bch_disk_group {
__u8 label[BCH_SB_LABEL_SIZE];
__le64 flags[2];
} __packed __aligned(8);
LE64_BITMASK(BCH_GROUP_DELETED, struct bch_disk_group, flags[0], 0, 1)
LE64_BITMASK(BCH_GROUP_DATA_ALLOWED, struct bch_disk_group, flags[0], 1, 6)
LE64_BITMASK(BCH_GROUP_PARENT, struct bch_disk_group, flags[0], 6, 24)
struct bch_sb_field_disk_groups {
struct bch_sb_field field;
struct bch_disk_group entries[];
} __packed __aligned(8);
/*
* On clean shutdown, store btree roots and current journal sequence number in
* the superblock:
*/
struct jset_entry {
__le16 u64s;
__u8 btree_id;
__u8 level;
__u8 type; /* designates what this jset holds */
__u8 pad[3];
struct bkey_i start[0];
__u64 _data[];
};
struct bch_sb_field_clean {
struct bch_sb_field field;
__le32 flags;
__le16 _read_clock; /* no longer used */
__le16 _write_clock;
__le64 journal_seq;
struct jset_entry start[0];
__u64 _data[];
};
struct journal_seq_blacklist_entry {
__le64 start;
__le64 end;
};
struct bch_sb_field_journal_seq_blacklist {
struct bch_sb_field field;
struct journal_seq_blacklist_entry start[];
};
struct bch_sb_field_errors {
struct bch_sb_field field;
struct bch_sb_field_error_entry {
__le64 v;
__le64 last_error_time;
} entries[];
};
LE64_BITMASK(BCH_SB_ERROR_ENTRY_ID, struct bch_sb_field_error_entry, v, 0, 16);
LE64_BITMASK(BCH_SB_ERROR_ENTRY_NR, struct bch_sb_field_error_entry, v, 16, 64);
struct bch_sb_field_ext {
struct bch_sb_field field;
__le64 recovery_passes_required[2];
__le64 errors_silent[8];
};
struct bch_sb_field_downgrade_entry {
__le16 version;
__le64 recovery_passes[2];
__le16 nr_errors;
__le16 errors[] __counted_by(nr_errors);
} __packed __aligned(2);
struct bch_sb_field_downgrade {
struct bch_sb_field field;
struct bch_sb_field_downgrade_entry entries[];
};
/* Superblock: */
/*
* New versioning scheme:
* One common version number for all on disk data structures - superblock, btree
* nodes, journal entries
*/
#define BCH_VERSION_MAJOR(_v) ((__u16) ((_v) >> 10))
#define BCH_VERSION_MINOR(_v) ((__u16) ((_v) & ~(~0U << 10)))
#define BCH_VERSION(_major, _minor) (((_major) << 10)|(_minor) << 0)
/*
* field 1: version name
* field 2: BCH_VERSION(major, minor)
* field 3: recovery passess required on upgrade
*/
#define BCH_METADATA_VERSIONS() \
x(bkey_renumber, BCH_VERSION(0, 10)) \
x(inode_btree_change, BCH_VERSION(0, 11)) \
x(snapshot, BCH_VERSION(0, 12)) \
x(inode_backpointers, BCH_VERSION(0, 13)) \
x(btree_ptr_sectors_written, BCH_VERSION(0, 14)) \
x(snapshot_2, BCH_VERSION(0, 15)) \
x(reflink_p_fix, BCH_VERSION(0, 16)) \
x(subvol_dirent, BCH_VERSION(0, 17)) \
x(inode_v2, BCH_VERSION(0, 18)) \
x(freespace, BCH_VERSION(0, 19)) \
x(alloc_v4, BCH_VERSION(0, 20)) \
x(new_data_types, BCH_VERSION(0, 21)) \
x(backpointers, BCH_VERSION(0, 22)) \
x(inode_v3, BCH_VERSION(0, 23)) \
x(unwritten_extents, BCH_VERSION(0, 24)) \
x(bucket_gens, BCH_VERSION(0, 25)) \
x(lru_v2, BCH_VERSION(0, 26)) \
x(fragmentation_lru, BCH_VERSION(0, 27)) \
x(no_bps_in_alloc_keys, BCH_VERSION(0, 28)) \
x(snapshot_trees, BCH_VERSION(0, 29)) \
x(major_minor, BCH_VERSION(1, 0)) \
x(snapshot_skiplists, BCH_VERSION(1, 1)) \
x(deleted_inodes, BCH_VERSION(1, 2)) \
x(rebalance_work, BCH_VERSION(1, 3)) \
x(member_seq, BCH_VERSION(1, 4)) \
x(subvolume_fs_parent, BCH_VERSION(1, 5)) \
x(btree_subvolume_children, BCH_VERSION(1, 6))
enum bcachefs_metadata_version {
bcachefs_metadata_version_min = 9,
#define x(t, n) bcachefs_metadata_version_##t = n,
BCH_METADATA_VERSIONS()
#undef x
bcachefs_metadata_version_max
};
static const __maybe_unused
unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
#define bcachefs_metadata_version_current (bcachefs_metadata_version_max - 1)
#define BCH_SB_SECTOR 8
#define BCH_SB_MEMBERS_MAX 64 /* XXX kill */
struct bch_sb_layout {
__uuid_t magic; /* bcachefs superblock UUID */
__u8 layout_type;
__u8 sb_max_size_bits; /* base 2 of 512 byte sectors */
__u8 nr_superblocks;
__u8 pad[5];
__le64 sb_offset[61];
} __packed __aligned(8);
#define BCH_SB_LAYOUT_SECTOR 7
/*
* @offset - sector where this sb was written
* @version - on disk format version
* @version_min - Oldest metadata version this filesystem contains; so we can
* safely drop compatibility code and refuse to mount filesystems
* we'd need it for
* @magic - identifies as a bcachefs superblock (BCHFS_MAGIC)
* @seq - incremented each time superblock is written
* @uuid - used for generating various magic numbers and identifying
* member devices, never changes
* @user_uuid - user visible UUID, may be changed
* @label - filesystem label
* @seq - identifies most recent superblock, incremented each time
* superblock is written
* @features - enabled incompatible features
*/
struct bch_sb {
struct bch_csum csum;
__le16 version;
__le16 version_min;
__le16 pad[2];
__uuid_t magic;
__uuid_t uuid;
__uuid_t user_uuid;
__u8 label[BCH_SB_LABEL_SIZE];
__le64 offset;
__le64 seq;
__le16 block_size;
__u8 dev_idx;
__u8 nr_devices;
__le32 u64s;
__le64 time_base_lo;
__le32 time_base_hi;
__le32 time_precision;
__le64 flags[7];
__le64 write_time;
__le64 features[2];
__le64 compat[2];
struct bch_sb_layout layout;
struct bch_sb_field start[0];
__le64 _data[];
} __packed __aligned(8);
/*
* Flags:
* BCH_SB_INITALIZED - set on first mount
* BCH_SB_CLEAN - did we shut down cleanly? Just a hint, doesn't affect
* behaviour of mount/recovery path:
* BCH_SB_INODE_32BIT - limit inode numbers to 32 bits
* BCH_SB_128_BIT_MACS - 128 bit macs instead of 80
* BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
* DATA/META_CSUM_TYPE. Also indicates encryption
* algorithm in use, if/when we get more than one
*/
LE16_BITMASK(BCH_SB_BLOCK_SIZE, struct bch_sb, block_size, 0, 16);
LE64_BITMASK(BCH_SB_INITIALIZED, struct bch_sb, flags[0], 0, 1);
LE64_BITMASK(BCH_SB_CLEAN, struct bch_sb, flags[0], 1, 2);
LE64_BITMASK(BCH_SB_CSUM_TYPE, struct bch_sb, flags[0], 2, 8);
LE64_BITMASK(BCH_SB_ERROR_ACTION, struct bch_sb, flags[0], 8, 12);
LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE, struct bch_sb, flags[0], 12, 28);
LE64_BITMASK(BCH_SB_GC_RESERVE, struct bch_sb, flags[0], 28, 33);
LE64_BITMASK(BCH_SB_ROOT_RESERVE, struct bch_sb, flags[0], 33, 40);
LE64_BITMASK(BCH_SB_META_CSUM_TYPE, struct bch_sb, flags[0], 40, 44);
LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE, struct bch_sb, flags[0], 44, 48);
LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52);
LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56);
LE64_BITMASK(BCH_SB_POSIX_ACL, struct bch_sb, flags[0], 56, 57);
LE64_BITMASK(BCH_SB_USRQUOTA, struct bch_sb, flags[0], 57, 58);
LE64_BITMASK(BCH_SB_GRPQUOTA, struct bch_sb, flags[0], 58, 59);
LE64_BITMASK(BCH_SB_PRJQUOTA, struct bch_sb, flags[0], 59, 60);
LE64_BITMASK(BCH_SB_HAS_ERRORS, struct bch_sb, flags[0], 60, 61);
LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
LE64_BITMASK(BCH_SB_BIG_ENDIAN, struct bch_sb, flags[0], 62, 63);
LE64_BITMASK(BCH_SB_STR_HASH_TYPE, struct bch_sb, flags[1], 0, 4);
LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1], 4, 8);
LE64_BITMASK(BCH_SB_INODE_32BIT, struct bch_sb, flags[1], 8, 9);
LE64_BITMASK(BCH_SB_128_BIT_MACS, struct bch_sb, flags[1], 9, 10);
LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE, struct bch_sb, flags[1], 10, 14);
/*
* Max size of an extent that may require bouncing to read or write
* (checksummed, compressed): 64k
*/
LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
struct bch_sb, flags[1], 14, 20);
LE64_BITMASK(BCH_SB_META_REPLICAS_REQ, struct bch_sb, flags[1], 20, 24);
LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ, struct bch_sb, flags[1], 24, 28);
LE64_BITMASK(BCH_SB_PROMOTE_TARGET, struct bch_sb, flags[1], 28, 40);
LE64_BITMASK(BCH_SB_FOREGROUND_TARGET, struct bch_sb, flags[1], 40, 52);
LE64_BITMASK(BCH_SB_BACKGROUND_TARGET, struct bch_sb, flags[1], 52, 64);
LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
struct bch_sb, flags[2], 0, 4);
LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES, struct bch_sb, flags[2], 4, 64);
LE64_BITMASK(BCH_SB_ERASURE_CODE, struct bch_sb, flags[3], 0, 16);
LE64_BITMASK(BCH_SB_METADATA_TARGET, struct bch_sb, flags[3], 16, 28);
LE64_BITMASK(BCH_SB_SHARD_INUMS, struct bch_sb, flags[3], 28, 29);
LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
LE64_BITMASK(BCH_SB_NOCOW, struct bch_sb, flags[4], 33, 34);
LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE, struct bch_sb, flags[4], 34, 54);
LE64_BITMASK(BCH_SB_VERSION_UPGRADE, struct bch_sb, flags[4], 54, 56);
LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,