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Diffstat (limited to 'fs/bcachefs/bcachefs_format.h')
| -rw-r--r-- | fs/bcachefs/bcachefs_format.h | 1465 |
1 files changed, 1465 insertions, 0 deletions
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h new file mode 100644 index 000000000000..5004f6ba997c --- /dev/null +++ b/fs/bcachefs/bcachefs_format.h @@ -0,0 +1,1465 @@ +/* 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 */ |