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linux-stable/fs/bcachefs/bcachefs_format.h
Kent Overstreet 83f33d6865 bcachefs: Rework lru btree 
This patch changes how the LRU index works:

Instead of using KEY_TYPE_lru where the bucket the lru entry points to
is part of the value, this switches to KEY_TYPE_set and encoding the
bucket we refer to in the low bits of the key.

This means that we no longer have to check for collisions when inserting
LRU entries. We'll be making using of this in the next patch, which adds
a btree write buffer - a pure write buffer for btree updates, where
updates are appended to a simple array and then periodically sorted and
batch inserted.

This is a new on disk format version, and a forced upgrade.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:52 -04:00

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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 unsigned name##_OFFSET = offset; \
static const 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 unsigned name##_OFFSET = offset; \
static const unsigned name##_BITS = (end - offset); \
static const __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 __aligned(4);
#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);
#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];
union {
struct {
/* Size of combined key and value, in u64s */
__u8 u64s;
};
struct {
struct bkey k;
struct bch_val v;
};
};
};
#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 { 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)
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;
};
/* Extents */
/*
* In extent bkeys, the value is a list of pointers (bch_extent_ptr), optionally
* preceded by checksum/compression information (bch_extent_crc32 or
* bch_extent_crc64).
*
* One major determining factor in the format of extents is how we handle and
* represent extents that have been partially overwritten and thus trimmed:
*
* If an extent is not checksummed or compressed, when the extent is trimmed we
* don't have to remember the extent we originally allocated and wrote: we can
* merely adjust ptr->offset to point to the start of the data that is currently
* live. The size field in struct bkey records the current (live) size of the
* extent, and is also used to mean "size of region on disk that we point to" in
* this case.
*
* Thus an extent that is not checksummed or compressed will consist only of a
* list of bch_extent_ptrs, with none of the fields in
* bch_extent_crc32/bch_extent_crc64.
*
* When an extent is checksummed or compressed, it's not possible to read only
* the data that is currently live: we have to read the entire extent that was
* originally written, and then return only the part of the extent that is
* currently live.
*
* Thus, in addition to the current size of the extent in struct bkey, we need
* to store the size of the originally allocated space - this is the
* compressed_size and uncompressed_size fields in bch_extent_crc32/64. Also,
* when the extent is trimmed, instead of modifying the offset field of the
* pointer, we keep a second smaller offset field - "offset into the original
* extent of the currently live region".
*
* The other major determining factor is replication and data migration:
*
* Each pointer may have its own bch_extent_crc32/64. When doing a replicated
* write, we will initially write all the replicas in the same format, with the
* same checksum type and compression format - however, when copygc runs later (or
* tiering/cache promotion, anything that moves data), it is not in general
* going to rewrite all the pointers at once - one of the replicas may be in a
* bucket on one device that has very little fragmentation while another lives
* in a bucket that has become heavily fragmented, and thus is being rewritten
* sooner than the rest.
*
* Thus it will only move a subset of the pointers (or in the case of
* tiering/cache promotion perhaps add a single pointer without dropping any
* current pointers), and if the extent has been partially overwritten it must
* write only the currently live portion (or copygc would not be able to reduce
* fragmentation!) - which necessitates a different bch_extent_crc format for
* the new pointer.
*
* But in the interests of space efficiency, we don't want to store one
* bch_extent_crc for each pointer if we don't have to.
*
* Thus, a bch_extent consists of bch_extent_crc32s, bch_extent_crc64s, and
* bch_extent_ptrs appended arbitrarily one after the other. We determine the
* type of a given entry with a scheme similar to utf8 (except we're encoding a
* type, not a size), encoding the type in the position of the first set bit:
*
* bch_extent_crc32 - 0b1
* bch_extent_ptr - 0b10
* bch_extent_crc64 - 0b100
*
* We do it this way because bch_extent_crc32 is _very_ constrained on bits (and
* bch_extent_crc64 is the least constrained).
*
* Then, each bch_extent_crc32/64 applies to the pointers that follow after it,
* until the next bch_extent_crc32/64.
*
* If there are no bch_extent_crcs preceding a bch_extent_ptr, then that pointer
* is neither checksummed nor compressed.
*/
/* 128 bits, sufficient for cryptographic MACs: */
struct bch_csum {
__le64 lo;
__le64 hi;
} __packed __aligned(8);
#define BCH_EXTENT_ENTRY_TYPES() \
x(ptr, 0) \
x(crc32, 1) \
x(crc64, 2) \
x(crc128, 3) \
x(stripe_ptr, 4)
#define BCH_EXTENT_ENTRY_MAX 5
enum bch_extent_entry_type {
#define x(f, n) BCH_EXTENT_ENTRY_##f = n,
BCH_EXTENT_ENTRY_TYPES()
#undef x
};
/* Compressed/uncompressed size are stored biased by 1: */
struct bch_extent_crc32 {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u32 type:2,
_compressed_size:7,
_uncompressed_size:7,
offset:7,
_unused:1,
csum_type:4,
compression_type:4;
__u32 csum;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u32 csum;
__u32 compression_type:4,
csum_type:4,
_unused:1,
offset:7,
_uncompressed_size:7,
_compressed_size:7,
type:2;
#endif
} __packed __aligned(8);
#define CRC32_SIZE_MAX (1U << 7)
#define CRC32_NONCE_MAX 0
struct bch_extent_crc64 {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u64 type:3,
_compressed_size:9,
_uncompressed_size:9,
offset:9,
nonce:10,
csum_type:4,
compression_type:4,
csum_hi:16;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u64 csum_hi:16,
compression_type:4,
csum_type:4,
nonce:10,
offset:9,
_uncompressed_size:9,
_compressed_size:9,
type:3;
#endif
__u64 csum_lo;
} __packed __aligned(8);
#define CRC64_SIZE_MAX (1U << 9)
#define CRC64_NONCE_MAX ((1U << 10) - 1)
struct bch_extent_crc128 {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u64 type:4,
_compressed_size:13,
_uncompressed_size:13,
offset:13,
nonce:13,
csum_type:4,
compression_type:4;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u64 compression_type:4,
csum_type:4,
nonce:13,
offset:13,
_uncompressed_size:13,
_compressed_size:13,
type:4;
#endif
struct bch_csum csum;
} __packed __aligned(8);
#define CRC128_SIZE_MAX (1U << 13)
#define CRC128_NONCE_MAX ((1U << 13) - 1)
/*
* @reservation - pointer hasn't been written to, just reserved
*/
struct bch_extent_ptr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u64 type:1,
cached:1,
unused:1,
unwritten:1,
offset:44, /* 8 petabytes */
dev:8,
gen:8;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u64 gen:8,
dev:8,
offset:44,
unwritten:1,
unused:1,
cached:1,
type:1;
#endif
} __packed __aligned(8);
struct bch_extent_stripe_ptr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u64 type:5,
block:8,
redundancy:4,
idx:47;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u64 idx:47,
redundancy:4,
block:8,
type:5;
#endif
};
struct bch_extent_reservation {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u64 type:6,
unused:22,
replicas:4,
generation:32;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u64 generation:32,
replicas:4,
unused:22,
type:6;
#endif
};
union bch_extent_entry {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ || __BITS_PER_LONG == 64
unsigned long type;
#elif __BITS_PER_LONG == 32
struct {
unsigned long pad;
unsigned long type;
};
#else
#error edit for your odd byteorder.
#endif
#define x(f, n) struct bch_extent_##f f;
BCH_EXTENT_ENTRY_TYPES()
#undef x
};
struct bch_btree_ptr {
struct bch_val v;
__u64 _data[0];
struct bch_extent_ptr start[];
} __packed __aligned(8);
struct bch_btree_ptr_v2 {
struct bch_val v;
__u64 mem_ptr;
__le64 seq;
__le16 sectors_written;
__le16 flags;
struct bpos min_key;
__u64 _data[0];
struct bch_extent_ptr start[];
} __packed __aligned(8);
LE16_BITMASK(BTREE_PTR_RANGE_UPDATED, struct bch_btree_ptr_v2, flags, 0, 1);
struct bch_extent {
struct bch_val v;
__u64 _data[0];
union bch_extent_entry start[];
} __packed __aligned(8);
struct bch_reservation {
struct bch_val v;
__le32 generation;
__u8 nr_replicas;
__u8 pad[3];
} __packed __aligned(8);
/* Maximum size (in u64s) a single pointer could be: */
#define BKEY_EXTENT_PTR_U64s_MAX\
((sizeof(struct bch_extent_crc128) + \
sizeof(struct bch_extent_ptr)) / sizeof(u64))
/* Maximum possible size of an entire extent value: */
#define BKEY_EXTENT_VAL_U64s_MAX \
(1 + BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1))
/* * Maximum possible size of an entire extent, key + value: */
#define BKEY_EXTENT_U64s_MAX (BKEY_U64s + BKEY_EXTENT_VAL_U64s_MAX)
/* Btree pointers don't carry around checksums: */
#define BKEY_BTREE_PTR_VAL_U64s_MAX \
((sizeof(struct bch_btree_ptr_v2) + \
sizeof(struct bch_extent_ptr) * BCH_REPLICAS_MAX) / sizeof(u64))
#define BKEY_BTREE_PTR_U64s_MAX \
(BKEY_U64s + BKEY_BTREE_PTR_VAL_U64s_MAX)
/* Inodes */
#define BLOCKDEV_INODE_MAX 4096
#define BCACHEFS_ROOT_INO 4096
struct bch_inode {
struct bch_val v;
__le64 bi_hash_seed;
__le32 bi_flags;
__le16 bi_mode;
__u8 fields[0];
} __packed __aligned(8);
struct bch_inode_v2 {
struct bch_val v;
__le64 bi_journal_seq;
__le64 bi_hash_seed;
__le64 bi_flags;
__le16 bi_mode;
__u8 fields[0];
} __packed __aligned(8);
struct bch_inode_v3 {
struct bch_val v;
__le64 bi_journal_seq;
__le64 bi_hash_seed;
__le64 bi_flags;
__le64 bi_sectors;
__le64 bi_size;
__le64 bi_version;
__u8 fields[0];
} __packed __aligned(8);
#define INODEv3_FIELDS_START_INITIAL 6
#define INODEv3_FIELDS_START_CUR (offsetof(struct bch_inode_v3, fields) / sizeof(u64))
struct bch_inode_generation {
struct bch_val v;
__le32 bi_generation;
__le32 pad;
} __packed __aligned(8);
/*
* bi_subvol and bi_parent_subvol are only set for subvolume roots:
*/
#define BCH_INODE_FIELDS_v2() \
x(bi_atime, 96) \
x(bi_ctime, 96) \
x(bi_mtime, 96) \
x(bi_otime, 96) \
x(bi_size, 64) \
x(bi_sectors, 64) \
x(bi_uid, 32) \
x(bi_gid, 32) \
x(bi_nlink, 32) \
x(bi_generation, 32) \
x(bi_dev, 32) \
x(bi_data_checksum, 8) \
x(bi_compression, 8) \
x(bi_project, 32) \
x(bi_background_compression, 8) \
x(bi_data_replicas, 8) \
x(bi_promote_target, 16) \
x(bi_foreground_target, 16) \
x(bi_background_target, 16) \
x(bi_erasure_code, 16) \
x(bi_fields_set, 16) \
x(bi_dir, 64) \
x(bi_dir_offset, 64) \
x(bi_subvol, 32) \
x(bi_parent_subvol, 32)
#define BCH_INODE_FIELDS_v3() \
x(bi_atime, 96) \
x(bi_ctime, 96) \
x(bi_mtime, 96) \
x(bi_otime, 96) \
x(bi_uid, 32) \
x(bi_gid, 32) \
x(bi_nlink, 32) \
x(bi_generation, 32) \
x(bi_dev, 32) \
x(bi_data_checksum, 8) \
x(bi_compression, 8) \
x(bi_project, 32) \
x(bi_background_compression, 8) \
x(bi_data_replicas, 8) \
x(bi_promote_target, 16) \
x(bi_foreground_target, 16) \
x(bi_background_target, 16) \
x(bi_erasure_code, 16) \
x(bi_fields_set, 16) \
x(bi_dir, 64) \
x(bi_dir_offset, 64) \
x(bi_subvol, 32) \
x(bi_parent_subvol, 32) \
x(bi_nocow, 8)
/* subset of BCH_INODE_FIELDS */
#define BCH_INODE_OPTS() \
x(data_checksum, 8) \
x(compression, 8) \
x(project, 32) \
x(background_compression, 8) \
x(data_replicas, 8) \
x(promote_target, 16) \
x(foreground_target, 16) \
x(background_target, 16) \
x(erasure_code, 16) \
x(nocow, 8)
enum inode_opt_id {
#define x(name, ...) \
Inode_opt_##name,
BCH_INODE_OPTS()
#undef x
Inode_opt_nr,
};
enum {
/*
* User flags (get/settable with FS_IOC_*FLAGS, correspond to FS_*_FL
* flags)
*/
__BCH_INODE_SYNC = 0,
__BCH_INODE_IMMUTABLE = 1,
__BCH_INODE_APPEND = 2,
__BCH_INODE_NODUMP = 3,
__BCH_INODE_NOATIME = 4,
__BCH_INODE_I_SIZE_DIRTY = 5,
__BCH_INODE_I_SECTORS_DIRTY = 6,
__BCH_INODE_UNLINKED = 7,
__BCH_INODE_BACKPTR_UNTRUSTED = 8,
/* bits 20+ reserved for packed fields below: */
};
#define BCH_INODE_SYNC (1 << __BCH_INODE_SYNC)
#define BCH_INODE_IMMUTABLE (1 << __BCH_INODE_IMMUTABLE)
#define BCH_INODE_APPEND (1 << __BCH_INODE_APPEND)
#define BCH_INODE_NODUMP (1 << __BCH_INODE_NODUMP)
#define BCH_INODE_NOATIME (1 << __BCH_INODE_NOATIME)
#define BCH_INODE_I_SIZE_DIRTY (1 << __BCH_INODE_I_SIZE_DIRTY)
#define BCH_INODE_I_SECTORS_DIRTY (1 << __BCH_INODE_I_SECTORS_DIRTY)
#define BCH_INODE_UNLINKED (1 << __BCH_INODE_UNLINKED)
#define BCH_INODE_BACKPTR_UNTRUSTED (1 << __BCH_INODE_BACKPTR_UNTRUSTED)
LE32_BITMASK(INODE_STR_HASH, struct bch_inode, bi_flags, 20, 24);
LE32_BITMASK(INODE_NR_FIELDS, struct bch_inode, bi_flags, 24, 31);
LE32_BITMASK(INODE_NEW_VARINT, struct bch_inode, bi_flags, 31, 32);
LE64_BITMASK(INODEv2_STR_HASH, struct bch_inode_v2, bi_flags, 20, 24);
LE64_BITMASK(INODEv2_NR_FIELDS, struct bch_inode_v2, bi_flags, 24, 31);
LE64_BITMASK(INODEv3_STR_HASH, struct bch_inode_v3, bi_flags, 20, 24);
LE64_BITMASK(INODEv3_NR_FIELDS, struct bch_inode_v3, bi_flags, 24, 31);
LE64_BITMASK(INODEv3_FIELDS_START,
struct bch_inode_v3, bi_flags, 31, 36);
LE64_BITMASK(INODEv3_MODE, struct bch_inode_v3, bi_flags, 36, 52);
/* Dirents */
/*
* Dirents (and xattrs) have to implement string lookups; since our b-tree
* doesn't support arbitrary length strings for the key, we instead index by a
* 64 bit hash (currently truncated sha1) of the string, stored in the offset
* field of the key - using linear probing to resolve hash collisions. This also
* provides us with the readdir cookie posix requires.
*
* Linear probing requires us to use whiteouts for deletions, in the event of a
* collision:
*/
struct bch_dirent {
struct bch_val v;
/* Target inode number: */
union {
__le64 d_inum;
struct { /* DT_SUBVOL */
__le32 d_child_subvol;
__le32 d_parent_subvol;
};
};
/*
* Copy of mode bits 12-15 from the target inode - so userspace can get
* the filetype without having to do a stat()
*/
__u8 d_type;
__u8 d_name[];
} __packed __aligned(8);
#define DT_SUBVOL 16
#define BCH_DT_MAX 17
#define BCH_NAME_MAX ((unsigned) (U8_MAX * sizeof(u64) - \
sizeof(struct bkey) - \
offsetof(struct bch_dirent, d_name)))
/* Xattrs */
#define KEY_TYPE_XATTR_INDEX_USER 0
#define KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS 1
#define KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT 2
#define KEY_TYPE_XATTR_INDEX_TRUSTED 3
#define KEY_TYPE_XATTR_INDEX_SECURITY 4
struct bch_xattr {
struct bch_val v;
__u8 x_type;
__u8 x_name_len;
__le16 x_val_len;
__u8 x_name[];
} __packed __aligned(8);
/* Bucket/allocation information: */
struct bch_alloc {
struct bch_val v;
__u8 fields;
__u8 gen;
__u8 data[];
} __packed __aligned(8);
#define BCH_ALLOC_FIELDS_V1() \
x(read_time, 16) \
x(write_time, 16) \
x(data_type, 8) \
x(dirty_sectors, 16) \
x(cached_sectors, 16) \
x(oldest_gen, 8) \
x(stripe, 32) \
x(stripe_redundancy, 8)
enum {
#define x(name, _bits) BCH_ALLOC_FIELD_V1_##name,
BCH_ALLOC_FIELDS_V1()
#undef x
};
struct bch_alloc_v2 {
struct bch_val v;
__u8 nr_fields;
__u8 gen;
__u8 oldest_gen;
__u8 data_type;
__u8 data[];
} __packed __aligned(8);
#define BCH_ALLOC_FIELDS_V2() \
x(read_time, 64) \
x(write_time, 64) \
x(dirty_sectors, 32) \
x(cached_sectors, 32) \
x(stripe, 32) \
x(stripe_redundancy, 8)
struct bch_alloc_v3 {
struct bch_val v;
__le64 journal_seq;
__le32 flags;
__u8 nr_fields;
__u8 gen;
__u8 oldest_gen;
__u8 data_type;
__u8 data[];
} __packed __aligned(8);
LE32_BITMASK(BCH_ALLOC_V3_NEED_DISCARD,struct bch_alloc_v3, flags, 0, 1)
LE32_BITMASK(BCH_ALLOC_V3_NEED_INC_GEN,struct bch_alloc_v3, flags, 1, 2)
struct bch_alloc_v4 {
struct bch_val v;
__u64 journal_seq;
__u32 flags;
__u8 gen;
__u8 oldest_gen;
__u8 data_type;
__u8 stripe_redundancy;
__u32 dirty_sectors;
__u32 cached_sectors;
__u64 io_time[2];
__u32 stripe;
__u32 nr_external_backpointers;
} __packed __aligned(8);
#define BCH_ALLOC_V4_U64s_V0 6
#define BCH_ALLOC_V4_U64s (sizeof(struct bch_alloc_v4) / sizeof(u64))
BITMASK(BCH_ALLOC_V4_NEED_DISCARD, struct bch_alloc_v4, flags, 0, 1)
BITMASK(BCH_ALLOC_V4_NEED_INC_GEN, struct bch_alloc_v4, flags, 1, 2)
BITMASK(BCH_ALLOC_V4_BACKPOINTERS_START,struct bch_alloc_v4, flags, 2, 8)
BITMASK(BCH_ALLOC_V4_NR_BACKPOINTERS, struct bch_alloc_v4, flags, 8, 14)
#define BCH_ALLOC_V4_NR_BACKPOINTERS_MAX 40
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);
#define KEY_TYPE_BUCKET_GENS_BITS 8
#define KEY_TYPE_BUCKET_GENS_NR (1U << KEY_TYPE_BUCKET_GENS_BITS)
#define KEY_TYPE_BUCKET_GENS_MASK (KEY_TYPE_BUCKET_GENS_NR - 1)
struct bch_bucket_gens {
struct bch_val v;
u8 gens[KEY_TYPE_BUCKET_GENS_NR];
} __packed __aligned(8);
/* Quotas: */
enum quota_types {
QTYP_USR = 0,
QTYP_GRP = 1,
QTYP_PRJ = 2,
QTYP_NR = 3,
};
enum quota_counters {
Q_SPC = 0,
Q_INO = 1,
Q_COUNTERS = 2,
};
struct bch_quota_counter {
__le64 hardlimit;
__le64 softlimit;
};
struct bch_quota {
struct bch_val v;
struct bch_quota_counter c[Q_COUNTERS];
} __packed __aligned(8);
/* Erasure coding */
struct bch_stripe {
struct bch_val v;
__le16 sectors;
__u8 algorithm;
__u8 nr_blocks;
__u8 nr_redundant;
__u8 csum_granularity_bits;
__u8 csum_type;
__u8 pad;
struct bch_extent_ptr ptrs[];
} __packed __aligned(8);
/* Reflink: */
struct bch_reflink_p {
struct bch_val v;
__le64 idx;
/*
* A reflink pointer might point to an indirect extent which is then
* later split (by copygc or rebalance). If we only pointed to part of
* the original indirect extent, and then one of the fragments is
* outside the range we point to, we'd leak a refcount: so when creating
* reflink pointers, we need to store pad values to remember the full
* range we were taking a reference on.
*/
__le32 front_pad;
__le32 back_pad;
} __packed __aligned(8);
struct bch_reflink_v {
struct bch_val v;
__le64 refcount;
union bch_extent_entry start[0];
__u64 _data[0];
} __packed __aligned(8);
struct bch_indirect_inline_data {
struct bch_val v;
__le64 refcount;
u8 data[0];
};
/* Inline data */
struct bch_inline_data {
struct bch_val v;
u8 data[0];
};
/* Subvolumes: */
#define SUBVOL_POS_MIN POS(0, 1)
#define SUBVOL_POS_MAX POS(0, S32_MAX)
#define BCACHEFS_ROOT_SUBVOL 1
struct bch_subvolume {
struct bch_val v;
__le32 flags;
__le32 snapshot;
__le64 inode;
};
LE32_BITMASK(BCH_SUBVOLUME_RO, struct bch_subvolume, flags, 0, 1)
/*
* We need to know whether a subvolume is a snapshot so we can know whether we
* can delete it (or whether it should just be rm -rf'd)
*/
LE32_BITMASK(BCH_SUBVOLUME_SNAP, struct bch_subvolume, flags, 1, 2)
LE32_BITMASK(BCH_SUBVOLUME_UNLINKED, struct bch_subvolume, flags, 2, 3)
/* Snapshots */
struct bch_snapshot {
struct bch_val v;
__le32 flags;
__le32 parent;
__le32 children[2];
__le32 subvol;
__le32 pad;
};
LE32_BITMASK(BCH_SNAPSHOT_DELETED, struct bch_snapshot, flags, 0, 1)
/* True if a subvolume points to this snapshot node: */
LE32_BITMASK(BCH_SNAPSHOT_SUBVOL, struct bch_snapshot, flags, 1, 2)
/* 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, 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)
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[0];
};
struct bch_sb_field_journal_v2 {
struct bch_sb_field field;
struct bch_sb_field_journal_v2_entry {
__le64 start;
__le64 nr;
} d[0];
};
/* BCH_SB_FIELD_members: */
#define BCH_MIN_NR_NBUCKETS (1 << 6)
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[2];
};
LE64_BITMASK(BCH_MEMBER_STATE, struct bch_member, flags[0], 0, 4)
/* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
LE64_BITMASK(BCH_MEMBER_DISCARD, struct bch_member, flags[0], 14, 15)
LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED, struct bch_member, flags[0], 15, 20)
LE64_BITMASK(BCH_MEMBER_GROUP, struct bch_member, flags[0], 20, 28)
LE64_BITMASK(BCH_MEMBER_DURABILITY, struct bch_member, flags[0], 28, 30)
LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
struct bch_member, flags[0], 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 {
struct bch_sb_field field;
struct bch_member members[0];
};
/* 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 {
__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 entries[];
} __packed __aligned(8);
/* BCH_SB_FIELD_quota: */
struct bch_sb_quota_counter {
__le32 timelimit;
__le32 warnlimit;
};
struct bch_sb_quota_type {
__le64 flags;
struct bch_sb_quota_counter c[Q_COUNTERS];
};
struct bch_sb_field_quota {
struct bch_sb_field field;
struct bch_sb_quota_type q[QTYP_NR];
} __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[0];
} __packed __aligned(8);
/* BCH_SB_FIELD_counters */
#define BCH_PERSISTENT_COUNTERS() \
x(io_read, 0) \
x(io_write, 1) \
x(io_move, 2) \
x(bucket_invalidate, 3) \
x(bucket_discard, 4) \
x(bucket_alloc, 5) \
x(bucket_alloc_fail, 6) \
x(btree_cache_scan, 7) \
x(btree_cache_reap, 8) \
x(btree_cache_cannibalize, 9) \
x(btree_cache_cannibalize_lock, 10) \
x(btree_cache_cannibalize_lock_fail, 11) \
x(btree_cache_cannibalize_unlock, 12) \
x(btree_node_write, 13) \
x(btree_node_read, 14) \
x(btree_node_compact, 15) \
x(btree_node_merge, 16) \
x(btree_node_split, 17) \
x(btree_node_rewrite, 18) \
x(btree_node_alloc, 19) \
x(btree_node_free, 20) \
x(btree_node_set_root, 21) \
x(btree_path_relock_fail, 22) \
x(btree_path_upgrade_fail, 23) \
x(btree_reserve_get_fail, 24) \
x(journal_entry_full, 25) \
x(journal_full, 26) \
x(journal_reclaim_finish, 27) \
x(journal_reclaim_start, 28) \
x(journal_write, 29) \
x(read_promote, 30) \
x(read_bounce, 31) \
x(read_split, 33) \
x(read_retry, 32) \
x(read_reuse_race, 34) \
x(move_extent_read, 35) \
x(move_extent_write, 36) \
x(move_extent_finish, 37) \
x(move_extent_fail, 38) \
x(move_extent_alloc_mem_fail, 39) \
x(copygc, 40) \
x(copygc_wait, 41) \
x(gc_gens_end, 42) \
x(gc_gens_start, 43) \
x(trans_blocked_journal_reclaim, 44) \
x(trans_restart_btree_node_reused, 45) \
x(trans_restart_btree_node_split, 46) \
x(trans_restart_fault_inject, 47) \
x(trans_restart_iter_upgrade, 48) \
x(trans_restart_journal_preres_get, 49) \
x(trans_restart_journal_reclaim, 50) \
x(trans_restart_journal_res_get, 51) \
x(trans_restart_key_cache_key_realloced, 52) \
x(trans_restart_key_cache_raced, 53) \
x(trans_restart_mark_replicas, 54) \
x(trans_restart_mem_realloced, 55) \
x(trans_restart_memory_allocation_failure, 56) \
x(trans_restart_relock, 57) \
x(trans_restart_relock_after_fill, 58) \
x(trans_restart_relock_key_cache_fill, 59) \
x(trans_restart_relock_next_node, 60) \
x(trans_restart_relock_parent_for_fill, 61) \
x(trans_restart_relock_path, 62) \
x(trans_restart_relock_path_intent, 63) \
x(trans_restart_too_many_iters, 64) \
x(trans_restart_traverse, 65) \
x(trans_restart_upgrade, 66) \
x(trans_restart_would_deadlock, 67) \
x(trans_restart_would_deadlock_write, 68) \
x(trans_restart_injected, 69) \
x(trans_restart_key_cache_upgrade, 70) \
x(trans_traverse_all, 71) \
x(transaction_commit, 72) \
x(write_super, 73) \
x(trans_restart_would_deadlock_recursion_limit, 74) \
x(trans_restart_write_buffer_flush, 75)
enum bch_persistent_counters {
#define x(t, n, ...) BCH_COUNTER_##t,
BCH_PERSISTENT_COUNTERS()
#undef x
BCH_COUNTER_NR
};
struct bch_sb_field_counters {
struct bch_sb_field field;
__le64 d[0];
};
/*
* 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];
union {
struct bkey_i start[0];
__u64 _data[0];
};
};
struct bch_sb_field_clean {
struct bch_sb_field field;
__le32 flags;
__le16 _read_clock; /* no longer used */
__le16 _write_clock;
__le64 journal_seq;
union {
struct jset_entry start[0];
__u64 _data[0];
};
};
struct journal_seq_blacklist_entry {
__le64 start;
__le64 end;
};
struct bch_sb_field_journal_seq_blacklist {
struct bch_sb_field field;
union {
struct journal_seq_blacklist_entry start[0];
__u64 _data[0];
};
};
/* Superblock: */
/*
* New versioning scheme:
* One common version number for all on disk data structures - superblock, btree
* nodes, journal entries
*/
#define BCH_JSET_VERSION_OLD 2
#define BCH_BSET_VERSION_OLD 3
#define BCH_METADATA_VERSIONS() \
x(bkey_renumber, 10) \
x(inode_btree_change, 11) \
x(snapshot, 12) \
x(inode_backpointers, 13) \
x(btree_ptr_sectors_written, 14) \
x(snapshot_2, 15) \
x(reflink_p_fix, 16) \
x(subvol_dirent, 17) \
x(inode_v2, 18) \
x(freespace, 19) \
x(alloc_v4, 20) \
x(new_data_types, 21) \
x(backpointers, 22) \
x(inode_v3, 23) \
x(unwritten_extents, 24) \
x(bucket_gens, 25) \
x(lru_v2, 26)
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
};
#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[8];
__le64 features[2];
__le64 compat[2];
struct bch_sb_layout layout;
union {
struct bch_sb_field start[0];
__le64 _data[0];
};
} __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, 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,
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);
/*
* Features:
*
* journal_seq_blacklist_v3: gates BCH_SB_FIELD_journal_seq_blacklist
* reflink: gates KEY_TYPE_reflink
* inline_data: gates KEY_TYPE_inline_data
* new_siphash: gates BCH_STR_HASH_siphash
* new_extent_overwrite: gates BTREE_NODE_NEW_EXTENT_OVERWRITE
*/
#define BCH_SB_FEATURES() \
x(lz4, 0) \
x(gzip, 1) \
x(zstd, 2) \
x(atomic_nlink, 3) \
x(ec, 4) \
x(journal_seq_blacklist_v3, 5) \
x(reflink, 6) \
x(new_siphash, 7) \
x(inline_data, 8) \
x(new_extent_overwrite, 9) \
x(incompressible, 10) \
x(btree_ptr_v2, 11) \
x(extents_above_btree_updates, 12) \
x(btree_updates_journalled, 13) \
x(reflink_inline_data, 14) \
x(new_varint, 15) \
x(journal_no_flush, 16) \
x(alloc_v2, 17) \
x(extents_across_btree_nodes, 18)
#define BCH_SB_FEATURES_ALWAYS \
((1ULL << BCH_FEATURE_new_extent_overwrite)| \
(1ULL << BCH_FEATURE_extents_above_btree_updates)|\
(1ULL << BCH_FEATURE_btree_updates_journalled)|\
(1ULL << BCH_FEATURE_alloc_v2)|\
(1ULL << BCH_FEATURE_extents_across_btree_nodes))
#define BCH_SB_FEATURES_ALL \
(BCH_SB_FEATURES_ALWAYS| \
(1ULL << BCH_FEATURE_new_siphash)| \
(1ULL << BCH_FEATURE_btree_ptr_v2)| \
(1ULL << BCH_FEATURE_new_varint)| \
(1ULL << BCH_FEATURE_journal_no_flush))
enum bch_sb_feature {
#define x(f, n) BCH_FEATURE_##f,
BCH_SB_FEATURES()
#undef x
BCH_FEATURE_NR,
};
#define BCH_SB_COMPAT() \
x(alloc_info, 0) \
x(alloc_metadata, 1) \
x(extents_above_btree_updates_done, 2) \
x(bformat_overflow_done, 3)
enum bch_sb_compat {
#define x(f, n) BCH_COMPAT_##f,
BCH_SB_COMPAT()
#undef x
BCH_COMPAT_NR,
};
/* options: */
#define BCH_REPLICAS_MAX 4U
#define BCH_BKEY_PTRS_MAX 16U
#define BCH_ERROR_ACTIONS() \
x(continue, 0) \
x(ro, 1) \
x(panic, 2)
enum bch_error_actions {
#define x(t, n) BCH_ON_ERROR_##t = n,
BCH_ERROR_ACTIONS()
#undef x
BCH_ON_ERROR_NR
};
#define BCH_STR_HASH_TYPES() \
x(crc32c, 0) \
x(crc64, 1) \
x(siphash_old, 2) \
x(siphash, 3)
enum bch_str_hash_type {
#define x(t, n) BCH_STR_HASH_##t = n,
BCH_STR_HASH_TYPES()
#undef x
BCH_STR_HASH_NR
};
#define BCH_STR_HASH_OPTS() \
x(crc32c, 0) \
x(crc64, 1) \
x(siphash, 2)
enum bch_str_hash_opts {
#define x(t, n) BCH_STR_HASH_OPT_##t = n,
BCH_STR_HASH_OPTS()
#undef x
BCH_STR_HASH_OPT_NR
};
#define BCH_CSUM_TYPES() \
x(none, 0) \
x(crc32c_nonzero, 1) \
x(crc64_nonzero, 2) \
x(chacha20_poly1305_80, 3) \
x(chacha20_poly1305_128, 4) \
x(crc32c, 5) \
x(crc64, 6) \
x(xxhash, 7)
enum bch_csum_type {
#define x(t, n) BCH_CSUM_##t = n,
BCH_CSUM_TYPES()
#undef x
BCH_CSUM_NR
};
static const unsigned bch_crc_bytes[] = {
[BCH_CSUM_none] = 0,
[BCH_CSUM_crc32c_nonzero] = 4,
[BCH_CSUM_crc32c] = 4,
[BCH_CSUM_crc64_nonzero] = 8,
[BCH_CSUM_crc64] = 8,
[BCH_CSUM_xxhash] = 8,
[BCH_CSUM_chacha20_poly1305_80] = 10,
[BCH_CSUM_chacha20_poly1305_128] = 16,
};
static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
{
switch (type) {
case BCH_CSUM_chacha20_poly1305_80:
case BCH_CSUM_chacha20_poly1305_128:
return true;
default:
return false;
}
}
#define BCH_CSUM_OPTS() \
x(none, 0) \
x(crc32c, 1) \
x(crc64, 2) \
x(xxhash, 3)
enum bch_csum_opts {
#define x(t, n) BCH_CSUM_OPT_##t = n,
BCH_CSUM_OPTS()
#undef x
BCH_CSUM_OPT_NR
};
#define BCH_COMPRESSION_TYPES() \
x(none, 0) \
x(lz4_old, 1) \
x(gzip, 2) \
x(lz4, 3) \
x(zstd, 4) \
x(incompressible, 5)
enum bch_compression_type {
#define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
BCH_COMPRESSION_TYPES()
#undef x
BCH_COMPRESSION_TYPE_NR
};
#define BCH_COMPRESSION_OPTS() \
x(none, 0) \
x(lz4, 1) \
x(gzip, 2) \
x(zstd, 3)
enum bch_compression_opts {
#define x(t, n) BCH_COMPRESSION_OPT_##t = n,
BCH_COMPRESSION_OPTS()
#undef x
BCH_COMPRESSION_OPT_NR
};
/*
* 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 BCACHE_MAGIC \
UUID_INIT(0xc68573f6, 0x4e1a, 0x45ca, \
0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
#define BCHFS_MAGIC \
UUID_INIT(0xc68573f6, 0x66ce, 0x90a9, \
0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
#define BCACHEFS_STATFS_MAGIC 0xca451a4e
#define JSET_MAGIC __cpu_to_le64(0x245235c1a3625032ULL)
#define BSET_MAGIC __cpu_to_le64(0x90135c78b99e07f5ULL)
static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
{
__le64 ret;
memcpy(&ret, &sb->uuid, sizeof(ret));
return ret;
}
static inline __u64 __jset_magic(struct bch_sb *sb)
{
return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
}
static inline __u64 __bset_magic(struct bch_sb *sb)
{
return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
}
/* Journal */
#define JSET_KEYS_U64s (sizeof(struct jset_entry) / sizeof(__u64))
#define BCH_JSET_ENTRY_TYPES() \
x(btree_keys, 0) \
x(btree_root, 1) \
x(prio_ptrs, 2) \
x(blacklist, 3) \
x(blacklist_v2, 4) \
x(usage, 5) \
x(data_usage, 6) \
x(clock, 7) \
x(dev_usage, 8) \
x(log, 9) \
x(overwrite, 10)
enum {
#define x(f, nr) BCH_JSET_ENTRY_##f = nr,
BCH_JSET_ENTRY_TYPES()
#undef x
BCH_JSET_ENTRY_NR
};
/*
* Journal sequence numbers can be blacklisted: bsets record the max sequence
* number of all the journal entries they contain updates for, so that on
* recovery we can ignore those bsets that contain index updates newer that what
* made it into the journal.
*
* This means that we can't reuse that journal_seq - we have to skip it, and
* then record that we skipped it so that the next time we crash and recover we
* don't think there was a missing journal entry.
*/
struct jset_entry_blacklist {
struct jset_entry entry;
__le64 seq;
};
struct jset_entry_blacklist_v2 {
struct jset_entry entry;
__le64 start;
__le64 end;
};
#define BCH_FS_USAGE_TYPES() \
x(reserved, 0) \
x(inodes, 1) \
x(key_version, 2)
enum {
#define x(f, nr) BCH_FS_USAGE_##f = nr,
BCH_FS_USAGE_TYPES()
#undef x
BCH_FS_USAGE_NR
};
struct jset_entry_usage {
struct jset_entry entry;
__le64 v;
} __packed;
struct jset_entry_data_usage {
struct jset_entry entry;
__le64 v;
struct bch_replicas_entry r;
} __packed;
struct jset_entry_clock {
struct jset_entry entry;
__u8 rw;
__u8 pad[7];
__le64 time;
} __packed;
struct jset_entry_dev_usage_type {
__le64 buckets;
__le64 sectors;
__le64 fragmented;
} __packed;
struct jset_entry_dev_usage {
struct jset_entry entry;
__le32 dev;
__u32 pad;
__le64 buckets_ec;
__le64 _buckets_unavailable; /* No longer used */
struct jset_entry_dev_usage_type d[];
} __packed;
static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
{
return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
sizeof(struct jset_entry_dev_usage_type);
}
struct jset_entry_log {
struct jset_entry entry;
u8 d[];
} __packed;
/*
* 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.
*/
struct jset {
struct bch_csum csum;
__le64 magic;
__le64 seq;
__le32 version;
__le32 flags;
__le32 u64s; /* size of d[] in u64s */
__u8 encrypted_start[0];
__le16 _read_clock; /* no longer used */
__le16 _write_clock;
/* Sequence number of oldest dirty journal entry */
__le64 last_seq;
union {
struct jset_entry start[0];
__u64 _data[0];
};
} __packed __aligned(8);
LE32_BITMASK(JSET_CSUM_TYPE, struct jset, flags, 0, 4);
LE32_BITMASK(JSET_BIG_ENDIAN, struct jset, flags, 4, 5);
LE32_BITMASK(JSET_NO_FLUSH, struct jset, flags, 5, 6);
#define BCH_JOURNAL_BUCKETS_MIN 8
/* Btree: */
#define BCH_BTREE_IDS() \
x(extents, 0) \
x(inodes, 1) \
x(dirents, 2) \
x(xattrs, 3) \
x(alloc, 4) \
x(quotas, 5) \
x(stripes, 6) \
x(reflink, 7) \
x(subvolumes, 8) \
x(snapshots, 9) \
x(lru, 10) \
x(freespace, 11) \
x(need_discard, 12) \
x(backpointers, 13) \
x(bucket_gens, 14)
enum btree_id {
#define x(kwd, val) BTREE_ID_##kwd = val,
BCH_BTREE_IDS()
#undef x
BTREE_ID_NR
};
#define BTREE_MAX_DEPTH 4U
/* Btree nodes */
/*
* Btree nodes
*
* On disk a btree node is a list/log of these; within each set the keys are
* sorted
*/
struct bset {
__le64 seq;
/*
* Highest journal entry this bset contains keys for.
* If on recovery we don't see that journal entry, this bset is ignored:
* this allows us to preserve the order of all index updates after a
* crash, since the journal records a total order of all index updates
* and anything that didn't make it to the journal doesn't get used.
*/
__le64 journal_seq;
__le32 flags;
__le16 version;
__le16 u64s; /* count of d[] in u64s */
union {
struct bkey_packed start[0];
__u64 _data[0];
};
} __packed __aligned(8);
LE32_BITMASK(BSET_CSUM_TYPE, struct bset, flags, 0, 4);
LE32_BITMASK(BSET_BIG_ENDIAN, struct bset, flags, 4, 5);
LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
struct bset, flags, 5, 6);
/* Sector offset within the btree node: */
LE32_BITMASK(BSET_OFFSET, struct bset, flags, 16, 32);
struct btree_node {
struct bch_csum csum;
__le64 magic;
/* this flags field is encrypted, unlike bset->flags: */
__le64 flags;
/* Closed interval: */
struct bpos min_key;
struct bpos max_key;
struct bch_extent_ptr _ptr; /* not used anymore */
struct bkey_format format;
union {
struct bset keys;
struct {
__u8 pad[22];
__le16 u64s;
__u64 _data[0];
};
};
} __packed __aligned(8);
LE64_BITMASK(BTREE_NODE_ID, struct btree_node, flags, 0, 4);
LE64_BITMASK(BTREE_NODE_LEVEL, struct btree_node, flags, 4, 8);
LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
struct btree_node, flags, 8, 9);
/* 9-32 unused */
LE64_BITMASK(BTREE_NODE_SEQ, struct btree_node, flags, 32, 64);
struct btree_node_entry {
struct bch_csum csum;
union {
struct bset keys;
struct {
__u8 pad[22];
__le16 u64s;
__u64 _data[0];
};
};
} __packed __aligned(8);
#endif /* _BCACHEFS_FORMAT_H */
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