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linux/fs/bcachefs/bcachefs_format.h
Kent Overstreet 9b23fdbd5d bcachefs: bcachefs_metadata_version_inode_has_child_snapshots 
There's an inherent race in taking a snapshot while an unlinked file is
open, and then reattaching it in the child snapshot.

In the interior snapshot node the file will appear unlinked, as though
it should be deleted - it's not referenced by anything in that snapshot
- but we can't delete it, because the file data is referenced by the
child snapshot.

This was being handled incorrectly with
propagate_key_to_snapshot_leaves() - but that doesn't resolve the
fundamental inconsistency of "this file looks like it should be deleted
according to normal rules, but - ".

To fix this, we need to fix the rule for when an inode is deleted. The
previous rule, ignoring snapshots (there was no well-defined rule
for with snapshots) was:
  Unlinked, non open files are deleted, either at recovery time or
  during online fsck

The new rule is:
  Unlinked, non open files, that do not exist in child snapshots, are
  deleted.

To make this work transactionally, we add a new inode flag,
BCH_INODE_has_child_snapshot; it overrides BCH_INODE_unlinked when
considering whether to delete an inode, or put it on the deleted list.

For transactional consistency, clearing it handled by the inode trigger:
when deleting an inode we check if there are parent inodes which can now
have the BCH_INODE_has_child_snapshot flag cleared.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-10-09 16:42:51 -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 <uapi/linux/magic.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
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
__aligned(4)
#endif
;
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 bversion;
__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 bversion;
__u8 pad[1];
#endif
} __packed
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
/*
* The big-endian version of bkey can't be compiled by rustc with the "aligned"
* attr since it doesn't allow types to have both "packed" and "aligned" attrs.
* So for Rust compatibility, don't include this. It can be included in the LE
* version because the "packed" attr is redundant in that case.
*
* History: (quoting Kent)
*
* Specifically, when i was designing bkey, I wanted the header to be no
* bigger than necessary so that bkey_packed could use the rest. That means that
* decently offten extent keys will fit into only 8 bytes, instead of spilling over
* to 16.
*
* But packed_bkey treats the part after the header - the packed section -
* as a single multi word, variable length integer. And bkey, the unpacked
* version, is just a special case version of a bkey_packed; all the packed
* bkey code will work on keys in any packed format, the in-memory
* representation of an unpacked key also is just one type of packed key...
*
* So that constrains the key part of a bkig endian bkey to start right
* after the header.
*
* If we ever do a bkey_v2 and need to expand the hedaer by another byte for
* some reason - that will clean up this wart.
*/
__aligned(8)
#endif
;
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, bversion.hi), \
bkey_format_field(VERSION_LO, bversion.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) \
x(accounting, 34)
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);
/* 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 "dirent_format.h"
#include "disk_accounting_format.h"
#include "disk_groups_format.h"
#include "extents_format.h"
#include "ec_format.h"
#include "dirent_format.h"
#include "disk_groups_format.h"
#include "inode_format.h"
#include "journal_seq_blacklist_format.h"
#include "logged_ops_format.h"
#include "lru_format.h"
#include "quota_format.h"
#include "reflink_format.h"
#include "replicas_format.h"
#include "snapshot_format.h"
#include "subvolume_format.h"
#include "sb-counters_format.h"
#include "sb-downgrade_format.h"
#include "sb-errors_format.h"
#include "sb-members_format.h"
#include "xattr_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_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);
/*
* 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 bch_sb_field_ext {
struct bch_sb_field field;
__le64 recovery_passes_required[2];
__le64 errors_silent[8];
__le64 btrees_lost_data;
};
/* 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)) \
x(mi_btree_bitmap, BCH_VERSION(1, 7)) \
x(bucket_stripe_sectors, BCH_VERSION(1, 8)) \
x(disk_accounting_v2, BCH_VERSION(1, 9)) \
x(disk_accounting_v3, BCH_VERSION(1, 10)) \
x(disk_accounting_inum, BCH_VERSION(1, 11)) \
x(rebalance_work_acct_fix, BCH_VERSION(1, 12)) \
x(inode_has_child_snapshots, BCH_VERSION(1, 13))
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_LAYOUT_SIZE_BITS_MAX 16 /* 32 MB */
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_PROMOTE_WHOLE_EXTENTS,
struct bch_sb, flags[0], 63, 64);
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,
struct bch_sb, flags[4], 60, 64);
LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE,
struct bch_sb, flags[5], 0, 16);
LE64_BITMASK(BCH_SB_ALLOCATOR_STUCK_TIMEOUT,
struct bch_sb, flags[5], 16, 32);
static inline __u64 BCH_SB_COMPRESSION_TYPE(const struct bch_sb *sb)
{
return BCH_SB_COMPRESSION_TYPE_LO(sb) | (BCH_SB_COMPRESSION_TYPE_HI(sb) << 4);
}
static inline void SET_BCH_SB_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
{
SET_BCH_SB_COMPRESSION_TYPE_LO(sb, v);
SET_BCH_SB_COMPRESSION_TYPE_HI(sb, v >> 4);
}
static inline __u64 BCH_SB_BACKGROUND_COMPRESSION_TYPE(const struct bch_sb *sb)
{
return BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb) |
(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb) << 4);
}
static inline void SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
{
SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb, v);
SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb, v >> 4);
}
/*
* 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_VERSION_UPGRADE_OPTS() \
x(compatible, 0) \
x(incompatible, 1) \
x(none, 2)
enum bch_version_upgrade_opts {
#define x(t, n) BCH_VERSION_UPGRADE_##t = n,
BCH_VERSION_UPGRADE_OPTS()
#undef x
};
#define BCH_REPLICAS_MAX 4U
#define BCH_BKEY_PTRS_MAX 16U
#define BCH_ERROR_ACTIONS() \
x(continue, 0) \
x(fix_safe, 1) \
x(panic, 2) \
x(ro, 3)
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 __maybe_unused 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 BCACHEFS_SUPER_MAGIC
#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) \
x(write_buffer_keys, 11) \
x(datetime, 12)
enum bch_jset_entry_type {
#define x(f, nr) BCH_JSET_ENTRY_##f = nr,
BCH_JSET_ENTRY_TYPES()
#undef x
BCH_JSET_ENTRY_NR
};
static inline bool jset_entry_is_key(struct jset_entry *e)
{
switch (e->type) {
case BCH_JSET_ENTRY_btree_keys:
case BCH_JSET_ENTRY_btree_root:
case BCH_JSET_ENTRY_write_buffer_keys:
return true;
}
return false;
}
/*
* 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 bch_fs_usage_type {
#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_v1 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; /* No longer used */
__le64 _buckets_unavailable; /* No longer used */
struct jset_entry_dev_usage_type d[];
};
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 __aligned(8);
struct jset_entry_datetime {
struct jset_entry entry;
__le64 seconds;
} __packed __aligned(8);
/*
* 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;
struct jset_entry start[0];
__u64 _data[];
} __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: */
enum btree_id_flags {
BTREE_ID_EXTENTS = BIT(0),
BTREE_ID_SNAPSHOTS = BIT(1),
BTREE_ID_SNAPSHOT_FIELD = BIT(2),
BTREE_ID_DATA = BIT(3),
};
#define BCH_BTREE_IDS() \
x(extents, 0, BTREE_ID_EXTENTS|BTREE_ID_SNAPSHOTS|BTREE_ID_DATA,\
BIT_ULL(KEY_TYPE_whiteout)| \
BIT_ULL(KEY_TYPE_error)| \
BIT_ULL(KEY_TYPE_cookie)| \
BIT_ULL(KEY_TYPE_extent)| \
BIT_ULL(KEY_TYPE_reservation)| \
BIT_ULL(KEY_TYPE_reflink_p)| \
BIT_ULL(KEY_TYPE_inline_data)) \
x(inodes, 1, BTREE_ID_SNAPSHOTS, \
BIT_ULL(KEY_TYPE_whiteout)| \
BIT_ULL(KEY_TYPE_inode)| \
BIT_ULL(KEY_TYPE_inode_v2)| \
BIT_ULL(KEY_TYPE_inode_v3)| \
BIT_ULL(KEY_TYPE_inode_generation)) \
x(dirents, 2, BTREE_ID_SNAPSHOTS, \
BIT_ULL(KEY_TYPE_whiteout)| \
BIT_ULL(KEY_TYPE_hash_whiteout)| \
BIT_ULL(KEY_TYPE_dirent)) \
x(xattrs, 3, BTREE_ID_SNAPSHOTS, \
BIT_ULL(KEY_TYPE_whiteout)| \
BIT_ULL(KEY_TYPE_cookie)| \
BIT_ULL(KEY_TYPE_hash_whiteout)| \
BIT_ULL(KEY_TYPE_xattr)) \
x(alloc, 4, 0, \
BIT_ULL(KEY_TYPE_alloc)| \
BIT_ULL(KEY_TYPE_alloc_v2)| \
BIT_ULL(KEY_TYPE_alloc_v3)| \
BIT_ULL(KEY_TYPE_alloc_v4)) \
x(quotas, 5, 0, \
BIT_ULL(KEY_TYPE_quota)) \
x(stripes, 6, 0, \
BIT_ULL(KEY_TYPE_stripe)) \
x(reflink, 7, BTREE_ID_EXTENTS|BTREE_ID_DATA, \
BIT_ULL(KEY_TYPE_reflink_v)| \
BIT_ULL(KEY_TYPE_indirect_inline_data)| \
BIT_ULL(KEY_TYPE_error)) \
x(subvolumes, 8, 0, \
BIT_ULL(KEY_TYPE_subvolume)) \
x(snapshots, 9, 0, \
BIT_ULL(KEY_TYPE_snapshot)) \
x(lru, 10, 0, \
BIT_ULL(KEY_TYPE_set)) \
x(freespace, 11, BTREE_ID_EXTENTS, \
BIT_ULL(KEY_TYPE_set)) \
x(need_discard, 12, 0, \
BIT_ULL(KEY_TYPE_set)) \
x(backpointers, 13, 0, \
BIT_ULL(KEY_TYPE_backpointer)) \
x(bucket_gens, 14, 0, \
BIT_ULL(KEY_TYPE_bucket_gens)) \
x(snapshot_trees, 15, 0, \
BIT_ULL(KEY_TYPE_snapshot_tree)) \
x(deleted_inodes, 16, BTREE_ID_SNAPSHOT_FIELD, \
BIT_ULL(KEY_TYPE_set)) \
x(logged_ops, 17, 0, \
BIT_ULL(KEY_TYPE_logged_op_truncate)| \
BIT_ULL(KEY_TYPE_logged_op_finsert)) \
x(rebalance_work, 18, BTREE_ID_SNAPSHOT_FIELD, \
BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie)) \
x(subvolume_children, 19, 0, \
BIT_ULL(KEY_TYPE_set)) \
x(accounting, 20, BTREE_ID_SNAPSHOT_FIELD, \
BIT_ULL(KEY_TYPE_accounting)) \
enum btree_id {
#define x(name, nr, ...) BTREE_ID_##name = nr,
BCH_BTREE_IDS()
#undef x
BTREE_ID_NR
};
/*
* Maximum number of btrees that we will _ever_ have under the current scheme,
* where we refer to them with 64 bit bitfields - and we also need a bit for
* the interior btree node type:
*/
#define BTREE_ID_NR_MAX 63
static inline bool btree_id_is_alloc(enum btree_id id)
{
switch (id) {
case BTREE_ID_alloc:
case BTREE_ID_backpointers:
case BTREE_ID_need_discard:
case BTREE_ID_freespace:
case BTREE_ID_bucket_gens:
return true;
default:
return false;
}
}
#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 */
struct bkey_packed start[0];
__u64 _data[];
} __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_LO, 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);
LE64_BITMASK(BTREE_NODE_ID_HI, struct btree_node, flags, 9, 25);
/* 25-32 unused */
LE64_BITMASK(BTREE_NODE_SEQ, struct btree_node, flags, 32, 64);
static inline __u64 BTREE_NODE_ID(struct btree_node *n)
{
return BTREE_NODE_ID_LO(n) | (BTREE_NODE_ID_HI(n) << 4);
}
static inline void SET_BTREE_NODE_ID(struct btree_node *n, __u64 v)
{
SET_BTREE_NODE_ID_LO(n, v);
SET_BTREE_NODE_ID_HI(n, v >> 4);
}
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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