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Diffstat (limited to 'fs/bcachefs/bcachefs_format.h')
| -rw-r--r-- | fs/bcachefs/bcachefs_format.h | 2454 |
1 files changed, 2454 insertions, 0 deletions
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h new file mode 100644 index 0000000000..fe78e87603 --- /dev/null +++ b/fs/bcachefs/bcachefs_format.h @@ -0,0 +1,2454 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHEFS_FORMAT_H +#define _BCACHEFS_FORMAT_H + +/* + * bcachefs on disk data structures + * + * OVERVIEW: + * + * There are three main types of on disk data structures in bcachefs (this is + * reduced from 5 in bcache) + * + * - superblock + * - journal + * - btree + * + * The btree is the primary structure; most metadata exists as keys in the + * various btrees. There are only a small number of btrees, they're not + * sharded - we have one btree for extents, another for inodes, et cetera. + * + * SUPERBLOCK: + * + * The superblock contains the location of the journal, the list of devices in + * the filesystem, and in general any metadata we need in order to decide + * whether we can start a filesystem or prior to reading the journal/btree + * roots. + * + * The superblock is extensible, and most of the contents of the superblock are + * in variable length, type tagged fields; see struct bch_sb_field. + * + * Backup superblocks do not reside in a fixed location; also, superblocks do + * not have a fixed size. To locate backup superblocks we have struct + * bch_sb_layout; we store a copy of this inside every superblock, and also + * before the first superblock. + * + * JOURNAL: + * + * The journal primarily records btree updates in the order they occurred; + * journal replay consists of just iterating over all the keys in the open + * journal entries and re-inserting them into the btrees. + * + * The journal also contains entry types for the btree roots, and blacklisted + * journal sequence numbers (see journal_seq_blacklist.c). + * + * BTREE: + * + * bcachefs btrees are copy on write b+ trees, where nodes are big (typically + * 128k-256k) and log structured. We use struct btree_node for writing the first + * entry in a given node (offset 0), and struct btree_node_entry for all + * subsequent writes. + * + * After the header, btree node entries contain a list of keys in sorted order. + * Values are stored inline with the keys; since values are variable length (and + * keys effectively are variable length too, due to packing) we can't do random + * access without building up additional in memory tables in the btree node read + * path. + * + * BTREE KEYS (struct bkey): + * + * The various btrees share a common format for the key - so as to avoid + * switching in fastpath lookup/comparison code - but define their own + * structures for the key values. + * + * The size of a key/value pair is stored as a u8 in units of u64s, so the max + * size is just under 2k. The common part also contains a type tag for the + * value, and a format field indicating whether the key is packed or not (and + * also meant to allow adding new key fields in the future, if desired). + * + * bkeys, when stored within a btree node, may also be packed. In that case, the + * bkey_format in that node is used to unpack it. Packed bkeys mean that we can + * be generous with field sizes in the common part of the key format (64 bit + * inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost. + */ + +#include <asm/types.h> +#include <asm/byteorder.h> +#include <linux/kernel.h> +#include <linux/uuid.h> +#include "vstructs.h" + +#ifdef __KERNEL__ +typedef uuid_t __uuid_t; +#endif + +#define BITMASK(name, type, field, offset, end) \ +static const __maybe_unused unsigned name##_OFFSET = offset; \ +static const __maybe_unused unsigned name##_BITS = (end - offset); \ + \ +static inline __u64 name(const type *k) \ +{ \ + return (k->field >> offset) & ~(~0ULL << (end - offset)); \ +} \ + \ +static inline void SET_##name(type *k, __u64 v) \ +{ \ + k->field &= ~(~(~0ULL << (end - offset)) << offset); \ + k->field |= (v & ~(~0ULL << (end - offset))) << offset; \ +} + +#define LE_BITMASK(_bits, name, type, field, offset, end) \ +static const __maybe_unused unsigned name##_OFFSET = offset; \ +static const __maybe_unused unsigned name##_BITS = (end - offset); \ +static const __maybe_unused __u##_bits name##_MAX = (1ULL << (end - offset)) - 1;\ + \ +static inline __u64 name(const type *k) \ +{ \ + return (__le##_bits##_to_cpu(k->field) >> offset) & \ + ~(~0ULL << (end - offset)); \ +} \ + \ +static inline void SET_##name(type *k, __u64 v) \ +{ \ + __u##_bits new = __le##_bits##_to_cpu(k->field); \ + \ + new &= ~(~(~0ULL << (end - offset)) << offset); \ + new |= (v & ~(~0ULL << (end - offset))) << offset; \ + k->field = __cpu_to_le##_bits(new); \ +} + +#define LE16_BITMASK(n, t, f, o, e) LE_BITMASK(16, n, t, f, o, e) +#define LE32_BITMASK(n, t, f, o, e) LE_BITMASK(32, n, t, f, o, e) +#define LE64_BITMASK(n, t, f, o, e) LE_BITMASK(64, n, t, f, o, e) + +struct bkey_format { + __u8 key_u64s; + __u8 nr_fields; + /* One unused slot for now: */ + __u8 bits_per_field[6]; + __le64 field_offset[6]; +}; + +/* Btree keys - all units are in sectors */ + +struct bpos { + /* + * Word order matches machine byte order - btree code treats a bpos as a + * single large integer, for search/comparison purposes + * + * Note that wherever a bpos is embedded in another on disk data + * structure, it has to be byte swabbed when reading in metadata that + * wasn't written in native endian order: + */ +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + __u32 snapshot; + __u64 offset; + __u64 inode; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + __u64 inode; + __u64 offset; /* Points to end of extent - sectors */ + __u32 snapshot; +#else +#error edit for your odd byteorder. +#endif +} __packed +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +__aligned(4) +#endif +; + +#define KEY_INODE_MAX ((__u64)~0ULL) +#define KEY_OFFSET_MAX ((__u64)~0ULL) +#define KEY_SNAPSHOT_MAX ((__u32)~0U) +#define KEY_SIZE_MAX ((__u32)~0U) + +static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot) +{ + return (struct bpos) { + .inode = inode, + .offset = offset, + .snapshot = snapshot, + }; +} + +#define POS_MIN SPOS(0, 0, 0) +#define POS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0) +#define SPOS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX) +#define POS(_inode, _offset) SPOS(_inode, _offset, 0) + +/* Empty placeholder struct, for container_of() */ +struct bch_val { + __u64 __nothing[0]; +}; + +struct bversion { +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + __u64 lo; + __u32 hi; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + __u32 hi; + __u64 lo; +#endif +} __packed __aligned(4); + +struct bkey { + /* Size of combined key and value, in u64s */ + __u8 u64s; + + /* Format of key (0 for format local to btree node) */ +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u8 format:7, + needs_whiteout:1; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u8 needs_whiteout:1, + format:7; +#else +#error edit for your odd byteorder. +#endif + + /* Type of the value */ + __u8 type; + +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + __u8 pad[1]; + + struct bversion version; + __u32 size; /* extent size, in sectors */ + struct bpos p; +#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + struct bpos p; + __u32 size; /* extent size, in sectors */ + struct bversion version; + + __u8 pad[1]; +#endif +} __packed __aligned(8); + +struct bkey_packed { + __u64 _data[0]; + + /* Size of combined key and value, in u64s */ + __u8 u64s; + + /* Format of key (0 for format local to btree node) */ + + /* + * XXX: next incompat on disk format change, switch format and + * needs_whiteout - bkey_packed() will be cheaper if format is the high + * bits of the bitfield + */ +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u8 format:7, + needs_whiteout:1; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u8 needs_whiteout:1, + format:7; +#endif + + /* Type of the value */ + __u8 type; + __u8 key_start[0]; + + /* + * We copy bkeys with struct assignment in various places, and while + * that shouldn't be done with packed bkeys we can't disallow it in C, + * and it's legal to cast a bkey to a bkey_packed - so padding it out + * to the same size as struct bkey should hopefully be safest. + */ + __u8 pad[sizeof(struct bkey) - 3]; +} __packed __aligned(8); + +typedef struct { + __le64 lo; + __le64 hi; +} bch_le128; + +#define BKEY_U64s (sizeof(struct bkey) / sizeof(__u64)) +#define BKEY_U64s_MAX U8_MAX +#define BKEY_VAL_U64s_MAX (BKEY_U64s_MAX - BKEY_U64s) + +#define KEY_PACKED_BITS_START 24 + +#define KEY_FORMAT_LOCAL_BTREE 0 +#define KEY_FORMAT_CURRENT 1 + +enum bch_bkey_fields { + BKEY_FIELD_INODE, + BKEY_FIELD_OFFSET, + BKEY_FIELD_SNAPSHOT, + BKEY_FIELD_SIZE, + BKEY_FIELD_VERSION_HI, + BKEY_FIELD_VERSION_LO, + BKEY_NR_FIELDS, +}; + +#define bkey_format_field(name, field) \ + [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8) + +#define BKEY_FORMAT_CURRENT \ +((struct bkey_format) { \ + .key_u64s = BKEY_U64s, \ + .nr_fields = BKEY_NR_FIELDS, \ + .bits_per_field = { \ + bkey_format_field(INODE, p.inode), \ + bkey_format_field(OFFSET, p.offset), \ + bkey_format_field(SNAPSHOT, p.snapshot), \ + bkey_format_field(SIZE, size), \ + bkey_format_field(VERSION_HI, version.hi), \ + bkey_format_field(VERSION_LO, version.lo), \ + }, \ +}) + +/* bkey with inline value */ +struct bkey_i { + __u64 _data[0]; + + struct bkey k; + struct bch_val v; +}; + +#define KEY(_inode, _offset, _size) \ +((struct bkey) { \ + .u64s = BKEY_U64s, \ + .format = KEY_FORMAT_CURRENT, \ + .p = POS(_inode, _offset), \ + .size = _size, \ +}) + +static inline void bkey_init(struct bkey *k) +{ + *k = KEY(0, 0, 0); +} + +#define bkey_bytes(_k) ((_k)->u64s * sizeof(__u64)) + +#define __BKEY_PADDED(key, pad) \ + struct bkey_i key; __u64 key ## _pad[pad] + +/* + * - DELETED keys are used internally to mark keys that should be ignored but + * override keys in composition order. Their version number is ignored. + * + * - DISCARDED keys indicate that the data is all 0s because it has been + * discarded. DISCARDs may have a version; if the version is nonzero the key + * will be persistent, otherwise the key will be dropped whenever the btree + * node is rewritten (like DELETED keys). + * + * - ERROR: any read of the data returns a read error, as the data was lost due + * to a failing device. Like DISCARDED keys, they can be removed (overridden) + * by new writes or cluster-wide GC. Node repair can also overwrite them with + * the same or a more recent version number, but not with an older version + * number. + * + * - WHITEOUT: for hash table btrees + */ +#define BCH_BKEY_TYPES() \ + x(deleted, 0) \ + x(whiteout, 1) \ + x(error, 2) \ + x(cookie, 3) \ + x(hash_whiteout, 4) \ + x(btree_ptr, 5) \ + x(extent, 6) \ + x(reservation, 7) \ + x(inode, 8) \ + x(inode_generation, 9) \ + x(dirent, 10) \ + x(xattr, 11) \ + x(alloc, 12) \ + x(quota, 13) \ + x(stripe, 14) \ + x(reflink_p, 15) \ + x(reflink_v, 16) \ + x(inline_data, 17) \ + x(btree_ptr_v2, 18) \ + x(indirect_inline_data, 19) \ + x(alloc_v2, 20) \ + x(subvolume, 21) \ + x(snapshot, 22) \ + x(inode_v2, 23) \ + x(alloc_v3, 24) \ + x(set, 25) \ + x(lru, 26) \ + x(alloc_v4, 27) \ + x(backpointer, 28) \ + x(inode_v3, 29) \ + x(bucket_gens, 30) \ + x(snapshot_tree, 31) \ + x(logged_op_truncate, 32) \ + x(logged_op_finsert, 33) + +enum bch_bkey_type { +#define x(name, nr) KEY_TYPE_##name = nr, + BCH_BKEY_TYPES() +#undef x + KEY_TYPE_MAX, +}; + +struct bch_deleted { + struct bch_val v; +}; + +struct bch_whiteout { + struct bch_val v; +}; + +struct bch_error { + struct bch_val v; +}; + +struct bch_cookie { + struct bch_val v; + __le64 cookie; +}; + +struct bch_hash_whiteout { + struct bch_val v; +}; + +struct bch_set { + struct bch_val v; +}; + +/* 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) \ + x(rebalance, 5) +#define BCH_EXTENT_ENTRY_MAX 6 + +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_rebalance { +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u64 type:6, + unused:34, + compression:8, /* enum bch_compression_opt */ + target:16; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u64 target:16, + compression:8, + unused:34, + 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[]; +} __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[]; +} __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[]; +} __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, +}; + +#define BCH_INODE_FLAGS() \ + x(sync, 0) \ + x(immutable, 1) \ + x(append, 2) \ + x(nodump, 3) \ + x(noatime, 4) \ + x(i_size_dirty, 5) \ + x(i_sectors_dirty, 6) \ + x(unlinked, 7) \ + x(backptr_untrusted, 8) + +/* bits 20+ reserved for packed fields below: */ + +enum bch_inode_flags { +#define x(t, n) BCH_INODE_##t = 1U << n, + BCH_INODE_FLAGS() +#undef x +}; + +enum __bch_inode_flags { +#define x(t, n) __BCH_INODE_##t = n, + BCH_INODE_FLAGS() +#undef x +}; + +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 512 + +/* 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; + __u64 fragmentation_lru; +} __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[]; +} __packed __aligned(8); + +struct bch_indirect_inline_data { + struct bch_val v; + __le64 refcount; + u8 data[]; +}; + +/* Inline data */ + +struct bch_inline_data { + struct bch_val v; + u8 data[]; +}; + +/* 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; + /* + * Snapshot subvolumes form a tree, separate from the snapshot nodes + * tree - if this subvolume is a snapshot, this is the ID of the + * subvolume it was created from: + */ + __le32 parent; + __le32 pad; + bch_le128 otime; +}; + +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; + /* corresponds to a bch_snapshot_tree in BTREE_ID_snapshot_trees */ + __le32 tree; + __le32 depth; + __le32 skip[3]; +}; + +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) + +/* + * Snapshot trees: + * + * The snapshot_trees btree gives us persistent indentifier for each tree of + * bch_snapshot nodes, and allow us to record and easily find the root/master + * subvolume that other snapshots were created from: + */ +struct bch_snapshot_tree { + struct bch_val v; + __le32 master_subvol; + __le32 root_snapshot; +}; + +/* LRU btree: */ + +struct bch_lru { + struct bch_val v; + __le64 idx; +} __packed __aligned(8); + +#define LRU_ID_STRIPES (1U << 16) + +/* Logged operations btree: */ + +struct bch_logged_op_truncate { + struct bch_val v; + __le32 subvol; + __le32 pad; + __le64 inum; + __le64 new_i_size; +}; + +enum logged_op_finsert_state { + LOGGED_OP_FINSERT_start, + LOGGED_OP_FINSERT_shift_extents, + LOGGED_OP_FINSERT_finish, +}; + +struct bch_logged_op_finsert { + struct bch_val v; + __u8 state; + __u8 pad[3]; + __le32 subvol; + __le64 inum; + __le64 dst_offset; + __le64 src_offset; + __le64 pos; +}; + +/* 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) + +enum bch_sb_field_type { +#define x(f, nr) BCH_SB_FIELD_##f = nr, + BCH_SB_FIELDS() +#undef x + BCH_SB_FIELD_NR +}; + +/* + * Most superblock fields are replicated in all device's superblocks - a few are + * not: + */ +#define BCH_SINGLE_DEVICE_SB_FIELDS \ + ((1U << BCH_SB_FIELD_journal)| \ + (1U << BCH_SB_FIELD_journal_v2)) + +/* BCH_SB_FIELD_journal: */ + +struct bch_sb_field_journal { + struct bch_sb_field field; + __le64 buckets[]; +}; + +struct bch_sb_field_journal_v2 { + struct bch_sb_field field; + + struct bch_sb_field_journal_v2_entry { + __le64 start; + __le64 nr; + } d[]; +}; + +/* BCH_SB_FIELD_members_v1: */ + +#define BCH_MIN_NR_NBUCKETS (1 << 6) + +#define BCH_IOPS_MEASUREMENTS() \ + x(seqread, 0) \ + x(seqwrite, 1) \ + x(randread, 2) \ + x(randwrite, 3) + +enum bch_iops_measurement { +#define x(t, n) BCH_IOPS_##t = n, + BCH_IOPS_MEASUREMENTS() +#undef x + BCH_IOPS_NR +}; + +#define BCH_MEMBER_ERROR_TYPES() \ + x(read, 0) \ + x(write, 1) \ + x(checksum, 2) + +enum bch_member_error_type { +#define x(t, n) BCH_MEMBER_ERROR_##t = n, + BCH_MEMBER_ERROR_TYPES() +#undef x + BCH_MEMBER_ERROR_NR +}; + +struct bch_member { + __uuid_t uuid; + __le64 nbuckets; /* device size */ + __le16 first_bucket; /* index of first bucket used */ + __le16 bucket_size; /* sectors */ + __le32 pad; + __le64 last_mount; /* time_t */ + + __le64 flags; + __le32 iops[4]; + __le64 errors[BCH_MEMBER_ERROR_NR]; + __le64 errors_at_reset[BCH_MEMBER_ERROR_NR]; + __le64 errors_reset_time; +}; + +#define BCH_MEMBER_V1_BYTES 56 + +LE64_BITMASK(BCH_MEMBER_STATE, struct bch_member, flags, 0, 4) +/* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */ +LE64_BITMASK(BCH_MEMBER_DISCARD, struct bch_member, flags, 14, 15) +LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED, struct bch_member, flags, 15, 20) +LE64_BITMASK(BCH_MEMBER_GROUP, struct bch_member, flags, 20, 28) +LE64_BITMASK(BCH_MEMBER_DURABILITY, struct bch_member, flags, 28, 30) +LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED, + struct bch_member, flags, 30, 31) + +#if 0 +LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS, struct bch_member, flags[1], 0, 20); +LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40); +#endif + +#define BCH_MEMBER_STATES() \ + x(rw, 0) \ + x(ro, 1) \ + x(failed, 2) \ + x(spare, 3) + +enum bch_member_state { +#define x(t, n) BCH_MEMBER_STATE_##t = n, + BCH_MEMBER_STATES() +#undef x + BCH_MEMBER_STATE_NR +}; + +struct bch_sb_field_members_v1 { + struct bch_sb_field field; + struct bch_member _members[]; //Members are now variable size +}; + +struct bch_sb_field_members_v2 { + struct bch_sb_field field; + __le16 member_bytes; //size of single member entry + u8 pad[6]; + struct bch_member _members[]; +}; + +/* BCH_SB_FIELD_crypt: */ + +struct nonce { + __le32 d[4]; +}; + +struct bch_key { + __le64 key[4]; +}; + +#define BCH_KEY_MAGIC \ + (((__u64) 'b' << 0)|((__u64) 'c' << 8)| \ + ((__u64) 'h' << 16)|((__u64) '*' << 24)| \ + ((__u64) '*' << 32)|((__u64) 'k' << 40)| \ + ((__u64) 'e' << 48)|((__u64) 'y' << 56)) + +struct bch_encrypted_key { + __le64 magic; + struct bch_key key; +}; + +/* + * If this field is present in the superblock, it stores an encryption key which + * is used encrypt all other data/metadata. The key will normally be encrypted + * with the key userspace provides, but if encryption has been turned off we'll + * just store the master key unencrypted in the superblock so we can access the + * previously encrypted data. + */ +struct bch_sb_field_crypt { + struct bch_sb_field field; + + __le64 flags; + __le64 kdf_flags; + struct bch_encrypted_key key; +}; + +LE64_BITMASK(BCH_CRYPT_KDF_TYPE, struct bch_sb_field_crypt, flags, 0, 4); + +enum bch_kdf_types { + BCH_KDF_SCRYPT = 0, + BCH_KDF_NR = 1, +}; + +/* stored as base 2 log of scrypt params: */ +LE64_BITMASK(BCH_KDF_SCRYPT_N, struct bch_sb_field_crypt, kdf_flags, 0, 16); +LE64_BITMASK(BCH_KDF_SCRYPT_R, struct bch_sb_field_crypt, kdf_flags, 16, 32); +LE64_BITMASK(BCH_KDF_SCRYPT_P, struct bch_sb_field_crypt, kdf_flags, 32, 48); + +/* BCH_SB_FIELD_replicas: */ + +#define BCH_DATA_TYPES() \ + x(free, 0) \ + x(sb, 1) \ + x(journal, 2) \ + x(btree, 3) \ + x(user, 4) \ + x(cached, 5) \ + x(parity, 6) \ + x(stripe, 7) \ + x(need_gc_gens, 8) \ + x(need_discard, 9) + +enum bch_data_type { +#define x(t, n) BCH_DATA_##t, + BCH_DATA_TYPES() +#undef x + BCH_DATA_NR +}; + +static inline bool data_type_is_empty(enum bch_data_type type) +{ + switch (type) { + case BCH_DATA_free: + case BCH_DATA_need_gc_gens: + case BCH_DATA_need_discard: + return true; + default: + return false; + } +} + +static inline bool data_type_is_hidden(enum bch_data_type type) +{ + switch (type) { + case BCH_DATA_sb: + case BCH_DATA_journal: + return true; + default: + return false; + } +} + +struct bch_replicas_entry_v0 { + __u8 data_type; + __u8 nr_devs; + __u8 devs[]; +} __packed; + +struct bch_sb_field_replicas_v0 { + struct bch_sb_field field; + struct bch_replicas_entry_v0 entries[]; +} __packed __aligned(8); + +struct bch_replicas_entry { + __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[]; +} __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_start_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) \ + x(trans_restart_split_race, 76) + +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[]; +}; + +/* + * On clean shutdown, store btree roots and current journal sequence number in + * the superblock: + */ +struct jset_entry { + __le16 u64s; + __u8 btree_id; + __u8 level; + __u8 type; /* designates what this jset holds */ + __u8 pad[3]; + + struct bkey_i start[0]; + __u64 _data[]; +}; + +struct bch_sb_field_clean { + struct bch_sb_field field; + + __le32 flags; + __le16 _read_clock; /* no longer used */ + __le16 _write_clock; + __le64 journal_seq; + + struct jset_entry start[0]; + __u64 _data[]; +}; + +struct journal_seq_blacklist_entry { + __le64 start; + __le64 end; +}; + +struct bch_sb_field_journal_seq_blacklist { + struct bch_sb_field field; + struct journal_seq_blacklist_entry start[]; +}; + +struct bch_sb_field_errors { + struct bch_sb_field field; + struct bch_sb_field_error_entry { + __le64 v; + __le64 last_error_time; + } entries[]; +}; + +LE64_BITMASK(BCH_SB_ERROR_ENTRY_ID, struct bch_sb_field_error_entry, v, 0, 16); +LE64_BITMASK(BCH_SB_ERROR_ENTRY_NR, struct bch_sb_field_error_entry, v, 16, 64); + +struct bch_sb_field_ext { + struct bch_sb_field field; + __le64 recovery_passes_required[2]; + __le64 errors_silent[8]; +}; + +struct bch_sb_field_downgrade_entry { + __le16 version; + __le64 recovery_passes[2]; + __le16 nr_errors; + __le16 errors[] __counted_by(nr_errors); +} __packed __aligned(2); + +struct bch_sb_field_downgrade { + struct bch_sb_field field; + struct bch_sb_field_downgrade_entry entries[]; +}; + +/* Superblock: */ + +/* + * New versioning scheme: + * One common version number for all on disk data structures - superblock, btree + * nodes, journal entries + */ +#define BCH_VERSION_MAJOR(_v) ((__u16) ((_v) >> 10)) +#define BCH_VERSION_MINOR(_v) ((__u16) ((_v) & ~(~0U << 10))) +#define BCH_VERSION(_major, _minor) (((_major) << 10)|(_minor) << 0) + +#define RECOVERY_PASS_ALL_FSCK (1ULL << 63) + +/* + * 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), \ + RECOVERY_PASS_ALL_FSCK) \ + x(inode_btree_change, BCH_VERSION(0, 11), \ + RECOVERY_PASS_ALL_FSCK) \ + x(snapshot, BCH_VERSION(0, 12), \ + RECOVERY_PASS_ALL_FSCK) \ + x(inode_backpointers, BCH_VERSION(0, 13), \ + RECOVERY_PASS_ALL_FSCK) \ + x(btree_ptr_sectors_written, BCH_VERSION(0, 14), \ + RECOVERY_PASS_ALL_FSCK) \ + x(snapshot_2, BCH_VERSION(0, 15), \ + BIT_ULL(BCH_RECOVERY_PASS_fs_upgrade_for_subvolumes)| \ + BIT_ULL(BCH_RECOVERY_PASS_initialize_subvolumes)| \ + RECOVERY_PASS_ALL_FSCK) \ + x(reflink_p_fix, BCH_VERSION(0, 16), \ + BIT_ULL(BCH_RECOVERY_PASS_fix_reflink_p)) \ + x(subvol_dirent, BCH_VERSION(0, 17), \ + RECOVERY_PASS_ALL_FSCK) \ + x(inode_v2, BCH_VERSION(0, 18), \ + RECOVERY_PASS_ALL_FSCK) \ + x(freespace, BCH_VERSION(0, 19), \ + RECOVERY_PASS_ALL_FSCK) \ + x(alloc_v4, BCH_VERSION(0, 20), \ + RECOVERY_PASS_ALL_FSCK) \ + x(new_data_types, BCH_VERSION(0, 21), \ + RECOVERY_PASS_ALL_FSCK) \ + x(backpointers, BCH_VERSION(0, 22), \ + RECOVERY_PASS_ALL_FSCK) \ + x(inode_v3, BCH_VERSION(0, 23), \ + RECOVERY_PASS_ALL_FSCK) \ + x(unwritten_extents, BCH_VERSION(0, 24), \ + RECOVERY_PASS_ALL_FSCK) \ + x(bucket_gens, BCH_VERSION(0, 25), \ + BIT_ULL(BCH_RECOVERY_PASS_bucket_gens_init)| \ + RECOVERY_PASS_ALL_FSCK) \ + x(lru_v2, BCH_VERSION(0, 26), \ + RECOVERY_PASS_ALL_FSCK) \ + x(fragmentation_lru, BCH_VERSION(0, 27), \ + RECOVERY_PASS_ALL_FSCK) \ + x(no_bps_in_alloc_keys, BCH_VERSION(0, 28), \ + RECOVERY_PASS_ALL_FSCK) \ + x(snapshot_trees, BCH_VERSION(0, 29), \ + RECOVERY_PASS_ALL_FSCK) \ + x(major_minor, BCH_VERSION(1, 0), \ + 0) \ + x(snapshot_skiplists, BCH_VERSION(1, 1), \ + BIT_ULL(BCH_RECOVERY_PASS_check_snapshots)) \ + x(deleted_inodes, BCH_VERSION(1, 2), \ + BIT_ULL(BCH_RECOVERY_PASS_check_inodes)) \ + x(rebalance_work, BCH_VERSION(1, 3), \ + BIT_ULL(BCH_RECOVERY_PASS_set_fs_needs_rebalance)) + +enum bcachefs_metadata_version { + bcachefs_metadata_version_min = 9, +#define x(t, n, upgrade_passes) bcachefs_metadata_version_##t = n, + BCH_METADATA_VERSIONS() +#undef x + bcachefs_metadata_version_max +}; + +static const __maybe_unused +unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work; + +#define bcachefs_metadata_version_current (bcachefs_metadata_version_max - 1) + +#define BCH_SB_SECTOR 8 +#define BCH_SB_MEMBERS_MAX 64 /* XXX kill */ + +struct bch_sb_layout { + __uuid_t magic; /* bcachefs superblock UUID */ + __u8 layout_type; + __u8 sb_max_size_bits; /* base 2 of 512 byte sectors */ + __u8 nr_superblocks; + __u8 pad[5]; + __le64 sb_offset[61]; +} __packed __aligned(8); + +#define BCH_SB_LAYOUT_SECTOR 7 + +/* + * @offset - sector where this sb was written + * @version - on disk format version + * @version_min - Oldest metadata version this filesystem contains; so we can + * safely drop compatibility code and refuse to mount filesystems + * we'd need it for + * @magic - identifies as a bcachefs superblock (BCHFS_MAGIC) + * @seq - incremented each time superblock is written + * @uuid - used for generating various magic numbers and identifying + * member devices, never changes + * @user_uuid - user visible UUID, may be changed + * @label - filesystem label + * @seq - identifies most recent superblock, incremented each time + * superblock is written + * @features - enabled incompatible features + */ +struct bch_sb { + struct bch_csum csum; + __le16 version; + __le16 version_min; + __le16 pad[2]; + __uuid_t magic; + __uuid_t uuid; + __uuid_t user_uuid; + __u8 label[BCH_SB_LABEL_SIZE]; + __le64 offset; + __le64 seq; + + __le16 block_size; + __u8 dev_idx; + __u8 nr_devices; + __le32 u64s; + + __le64 time_base_lo; + __le32 time_base_hi; + __le32 time_precision; + + __le64 flags[8]; + __le64 features[2]; + __le64 compat[2]; + + struct bch_sb_layout layout; + + struct bch_sb_field start[0]; + __le64 _data[]; +} __packed __aligned(8); + +/* + * Flags: + * BCH_SB_INITALIZED - set on first mount + * BCH_SB_CLEAN - did we shut down cleanly? Just a hint, doesn't affect + * behaviour of mount/recovery path: + * BCH_SB_INODE_32BIT - limit inode numbers to 32 bits + * BCH_SB_128_BIT_MACS - 128 bit macs instead of 80 + * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides + * DATA/META_CSUM_TYPE. Also indicates encryption + * algorithm in use, if/when we get more than one + */ + +LE16_BITMASK(BCH_SB_BLOCK_SIZE, struct bch_sb, block_size, 0, 16); + +LE64_BITMASK(BCH_SB_INITIALIZED, struct bch_sb, flags[0], 0, 1); +LE64_BITMASK(BCH_SB_CLEAN, struct bch_sb, flags[0], 1, 2); +LE64_BITMASK(BCH_SB_CSUM_TYPE, struct bch_sb, flags[0], 2, 8); +LE64_BITMASK(BCH_SB_ERROR_ACTION, struct bch_sb, flags[0], 8, 12); + +LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE, struct bch_sb, flags[0], 12, 28); + +LE64_BITMASK(BCH_SB_GC_RESERVE, struct bch_sb, flags[0], 28, 33); +LE64_BITMASK(BCH_SB_ROOT_RESERVE, struct bch_sb, flags[0], 33, 40); + +LE64_BITMASK(BCH_SB_META_CSUM_TYPE, struct bch_sb, flags[0], 40, 44); +LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE, struct bch_sb, flags[0], 44, 48); + +LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52); +LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56); + +LE64_BITMASK(BCH_SB_POSIX_ACL, struct bch_sb, flags[0], 56, 57); +LE64_BITMASK(BCH_SB_USRQUOTA, struct bch_sb, flags[0], 57, 58); +LE64_BITMASK(BCH_SB_GRPQUOTA, struct bch_sb, flags[0], 58, 59); +LE64_BITMASK(BCH_SB_PRJQUOTA, struct bch_sb, flags[0], 59, 60); + +LE64_BITMASK(BCH_SB_HAS_ERRORS, struct bch_sb, flags[0], 60, 61); +LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62); + +LE64_BITMASK(BCH_SB_BIG_ENDIAN, struct bch_sb, flags[0], 62, 63); + +LE64_BITMASK(BCH_SB_STR_HASH_TYPE, struct bch_sb, flags[1], 0, 4); +LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1], 4, 8); +LE64_BITMASK(BCH_SB_INODE_32BIT, struct bch_sb, flags[1], 8, 9); + +LE64_BITMASK(BCH_SB_128_BIT_MACS, struct bch_sb, flags[1], 9, 10); +LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE, struct bch_sb, flags[1], 10, 14); + +/* + * Max size of an extent that may require bouncing to read or write + * (checksummed, compressed): 64k + */ +LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS, + struct bch_sb, flags[1], 14, 20); + +LE64_BITMASK(BCH_SB_META_REPLICAS_REQ, struct bch_sb, flags[1], 20, 24); +LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ, struct bch_sb, flags[1], 24, 28); + +LE64_BITMASK(BCH_SB_PROMOTE_TARGET, struct bch_sb, flags[1], 28, 40); +LE64_BITMASK(BCH_SB_FOREGROUND_TARGET, struct bch_sb, flags[1], 40, 52); +LE64_BITMASK(BCH_SB_BACKGROUND_TARGET, struct bch_sb, flags[1], 52, 64); + +LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO, + struct bch_sb, flags[2], 0, 4); +LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES, struct bch_sb, flags[2], 4, 64); + +LE64_BITMASK(BCH_SB_ERASURE_CODE, struct bch_sb, flags[3], 0, 16); +LE64_BITMASK(BCH_SB_METADATA_TARGET, struct bch_sb, flags[3], 16, 28); +LE64_BITMASK(BCH_SB_SHARD_INUMS, struct bch_sb, flags[3], 28, 29); +LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30); +LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62); +LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63); +LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32); +LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33); +LE64_BITMASK(BCH_SB_NOCOW, struct bch_sb, flags[4], 33, 34); +LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE, struct bch_sb, flags[4], 34, 54); +LE64_BITMASK(BCH_SB_VERSION_UPGRADE, struct bch_sb, flags[4], 54, 56); + +LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60); +LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI, + struct bch_sb, flags[4], 60, 64); + +LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE, + struct bch_sb, flags[5], 0, 16); + +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(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 __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 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[]; +}; + +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; + + + 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)) \ + 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)) + +enum btree_id { +#define x(name, nr, ...) BTREE_ID_##name = nr, + 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 */ + + 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 */ |