--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_FORMAT_H
+#define _BCACHEFS_FORMAT_H
+
+/*
+ * bcachefs on disk data structures
+ *
+ * OVERVIEW:
+ *
+ * There are three main types of on disk data structures in bcachefs (this is
+ * reduced from 5 in bcache)
+ *
+ * - superblock
+ * - journal
+ * - btree
+ *
+ * The btree is the primary structure; most metadata exists as keys in the
+ * various btrees. There are only a small number of btrees, they're not
+ * sharded - we have one btree for extents, another for inodes, et cetera.
+ *
+ * SUPERBLOCK:
+ *
+ * The superblock contains the location of the journal, the list of devices in
+ * the filesystem, and in general any metadata we need in order to decide
+ * whether we can start a filesystem or prior to reading the journal/btree
+ * roots.
+ *
+ * The superblock is extensible, and most of the contents of the superblock are
+ * in variable length, type tagged fields; see struct bch_sb_field.
+ *
+ * Backup superblocks do not reside in a fixed location; also, superblocks do
+ * not have a fixed size. To locate backup superblocks we have struct
+ * bch_sb_layout; we store a copy of this inside every superblock, and also
+ * before the first superblock.
+ *
+ * JOURNAL:
+ *
+ * The journal primarily records btree updates in the order they occurred;
+ * journal replay consists of just iterating over all the keys in the open
+ * journal entries and re-inserting them into the btrees.
+ *
+ * The journal also contains entry types for the btree roots, and blacklisted
+ * journal sequence numbers (see journal_seq_blacklist.c).
+ *
+ * BTREE:
+ *
+ * bcachefs btrees are copy on write b+ trees, where nodes are big (typically
+ * 128k-256k) and log structured. We use struct btree_node for writing the first
+ * entry in a given node (offset 0), and struct btree_node_entry for all
+ * subsequent writes.
+ *
+ * After the header, btree node entries contain a list of keys in sorted order.
+ * Values are stored inline with the keys; since values are variable length (and
+ * keys effectively are variable length too, due to packing) we can't do random
+ * access without building up additional in memory tables in the btree node read
+ * path.
+ *
+ * BTREE KEYS (struct bkey):
+ *
+ * The various btrees share a common format for the key - so as to avoid
+ * switching in fastpath lookup/comparison code - but define their own
+ * structures for the key values.
+ *
+ * The size of a key/value pair is stored as a u8 in units of u64s, so the max
+ * size is just under 2k. The common part also contains a type tag for the
+ * value, and a format field indicating whether the key is packed or not (and
+ * also meant to allow adding new key fields in the future, if desired).
+ *
+ * bkeys, when stored within a btree node, may also be packed. In that case, the
+ * bkey_format in that node is used to unpack it. Packed bkeys mean that we can
+ * be generous with field sizes in the common part of the key format (64 bit
+ * inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost.
+ */
+
+#include <asm/types.h>
+#include <asm/byteorder.h>
+#include <linux/kernel.h>
+#include <linux/uuid.h>
+#include "vstructs.h"
+
+#ifdef __KERNEL__
+typedef uuid_t __uuid_t;
+#endif
+
+#define BITMASK(name, type, field, offset, end) \
+static const __maybe_unused unsigned name##_OFFSET = offset; \
+static const __maybe_unused unsigned name##_BITS = (end - offset); \
+ \
+static inline __u64 name(const type *k) \
+{ \
+ return (k->field >> offset) & ~(~0ULL << (end - offset)); \
+} \
+ \
+static inline void SET_##name(type *k, __u64 v) \
+{ \
+ k->field &= ~(~(~0ULL << (end - offset)) << offset); \
+ k->field |= (v & ~(~0ULL << (end - offset))) << offset; \
+}
+
+#define LE_BITMASK(_bits, name, type, field, offset, end) \
+static const __maybe_unused unsigned name##_OFFSET = offset; \
+static const __maybe_unused unsigned name##_BITS = (end - offset); \
+static const __maybe_unused __u##_bits name##_MAX = (1ULL << (end - offset)) - 1;\
+ \
+static inline __u64 name(const type *k) \
+{ \
+ return (__le##_bits##_to_cpu(k->field) >> offset) & \
+ ~(~0ULL << (end - offset)); \
+} \
+ \
+static inline void SET_##name(type *k, __u64 v) \
+{ \
+ __u##_bits new = __le##_bits##_to_cpu(k->field); \
+ \
+ new &= ~(~(~0ULL << (end - offset)) << offset); \
+ new |= (v & ~(~0ULL << (end - offset))) << offset; \
+ k->field = __cpu_to_le##_bits(new); \
+}
+
+#define LE16_BITMASK(n, t, f, o, e) LE_BITMASK(16, n, t, f, o, e)
+#define LE32_BITMASK(n, t, f, o, e) LE_BITMASK(32, n, t, f, o, e)
+#define LE64_BITMASK(n, t, f, o, e) LE_BITMASK(64, n, t, f, o, e)
+
+struct bkey_format {
+ __u8 key_u64s;
+ __u8 nr_fields;
+ /* One unused slot for now: */
+ __u8 bits_per_field[6];
+ __le64 field_offset[6];
+};
+
+/* Btree keys - all units are in sectors */
+
+struct bpos {
+ /*
+ * Word order matches machine byte order - btree code treats a bpos as a
+ * single large integer, for search/comparison purposes
+ *
+ * Note that wherever a bpos is embedded in another on disk data
+ * structure, it has to be byte swabbed when reading in metadata that
+ * wasn't written in native endian order:
+ */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ __u32 snapshot;
+ __u64 offset;
+ __u64 inode;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ __u64 inode;
+ __u64 offset; /* Points to end of extent - sectors */
+ __u32 snapshot;
+#else
+#error edit for your odd byteorder.
+#endif
+} __packed
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+__aligned(4)
+#endif
+;
+
+#define KEY_INODE_MAX ((__u64)~0ULL)
+#define KEY_OFFSET_MAX ((__u64)~0ULL)
+#define KEY_SNAPSHOT_MAX ((__u32)~0U)
+#define KEY_SIZE_MAX ((__u32)~0U)
+
+static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
+{
+ return (struct bpos) {
+ .inode = inode,
+ .offset = offset,
+ .snapshot = snapshot,
+ };
+}
+
+#define POS_MIN SPOS(0, 0, 0)
+#define POS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
+#define SPOS_MAX SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
+#define POS(_inode, _offset) SPOS(_inode, _offset, 0)
+
+/* Empty placeholder struct, for container_of() */
+struct bch_val {
+ __u64 __nothing[0];
+};
+
+struct bversion {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ __u64 lo;
+ __u32 hi;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ __u32 hi;
+ __u64 lo;
+#endif
+} __packed __aligned(4);
+
+struct bkey {
+ /* Size of combined key and value, in u64s */
+ __u8 u64s;
+
+ /* Format of key (0 for format local to btree node) */
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 format:7,
+ needs_whiteout:1;
+#elif defined (__BIG_ENDIAN_BITFIELD)
+ __u8 needs_whiteout:1,
+ format:7;
+#else
+#error edit for your odd byteorder.
+#endif
+
+ /* Type of the value */
+ __u8 type;
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ __u8 pad[1];
+
+ struct bversion version;
+ __u32 size; /* extent size, in sectors */
+ struct bpos p;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ struct bpos p;
+ __u32 size; /* extent size, in sectors */
+ struct bversion version;
+
+ __u8 pad[1];
+#endif
+} __packed __aligned(8);
+
+struct bkey_packed {
+ __u64 _data[0];
+
+ /* Size of combined key and value, in u64s */
+ __u8 u64s;
+
+ /* Format of key (0 for format local to btree node) */
+
+ /*
+ * XXX: next incompat on disk format change, switch format and
+ * needs_whiteout - bkey_packed() will be cheaper if format is the high
+ * bits of the bitfield
+ */
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 format:7,
+ needs_whiteout:1;
+#elif defined (__BIG_ENDIAN_BITFIELD)
+ __u8 needs_whiteout:1,
+ format:7;
+#endif
+
+ /* Type of the value */
+ __u8 type;
+ __u8 key_start[0];
+
+ /*
+ * We copy bkeys with struct assignment in various places, and while
+ * that shouldn't be done with packed bkeys we can't disallow it in C,
+ * and it's legal to cast a bkey to a bkey_packed - so padding it out
+ * to the same size as struct bkey should hopefully be safest.
+ */
+ __u8 pad[sizeof(struct bkey) - 3];
+} __packed __aligned(8);
+
+typedef struct {
+ __le64 lo;
+ __le64 hi;
+} bch_le128;
+
+#define BKEY_U64s (sizeof(struct bkey) / sizeof(__u64))
+#define BKEY_U64s_MAX U8_MAX
+#define BKEY_VAL_U64s_MAX (BKEY_U64s_MAX - BKEY_U64s)
+
+#define KEY_PACKED_BITS_START 24
+
+#define KEY_FORMAT_LOCAL_BTREE 0
+#define KEY_FORMAT_CURRENT 1
+
+enum bch_bkey_fields {
+ BKEY_FIELD_INODE,
+ BKEY_FIELD_OFFSET,
+ BKEY_FIELD_SNAPSHOT,
+ BKEY_FIELD_SIZE,
+ BKEY_FIELD_VERSION_HI,
+ BKEY_FIELD_VERSION_LO,
+ BKEY_NR_FIELDS,
+};
+
+#define bkey_format_field(name, field) \
+ [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
+
+#define BKEY_FORMAT_CURRENT \
+((struct bkey_format) { \
+ .key_u64s = BKEY_U64s, \
+ .nr_fields = BKEY_NR_FIELDS, \
+ .bits_per_field = { \
+ bkey_format_field(INODE, p.inode), \
+ bkey_format_field(OFFSET, p.offset), \
+ bkey_format_field(SNAPSHOT, p.snapshot), \
+ bkey_format_field(SIZE, size), \
+ bkey_format_field(VERSION_HI, version.hi), \
+ bkey_format_field(VERSION_LO, version.lo), \
+ }, \
+})
+
+/* bkey with inline value */
+struct bkey_i {
+ __u64 _data[0];
+
+ struct bkey k;
+ struct bch_val v;
+};
+
+#define POS_KEY(_pos) \
+((struct bkey) { \
+ .u64s = BKEY_U64s, \
+ .format = KEY_FORMAT_CURRENT, \
+ .p = _pos, \
+})
+
+#define KEY(_inode, _offset, _size) \
+((struct bkey) { \
+ .u64s = BKEY_U64s, \
+ .format = KEY_FORMAT_CURRENT, \
+ .p = POS(_inode, _offset), \
+ .size = _size, \
+})
+
+static inline void bkey_init(struct bkey *k)
+{
+ *k = KEY(0, 0, 0);
+}
+
+#define bkey_bytes(_k) ((_k)->u64s * sizeof(__u64))
+
+#define __BKEY_PADDED(key, pad) \
+ struct bkey_i key; __u64 key ## _pad[pad]
+
+/*
+ * - DELETED keys are used internally to mark keys that should be ignored but
+ * override keys in composition order. Their version number is ignored.
+ *
+ * - DISCARDED keys indicate that the data is all 0s because it has been
+ * discarded. DISCARDs may have a version; if the version is nonzero the key
+ * will be persistent, otherwise the key will be dropped whenever the btree
+ * node is rewritten (like DELETED keys).
+ *
+ * - ERROR: any read of the data returns a read error, as the data was lost due
+ * to a failing device. Like DISCARDED keys, they can be removed (overridden)
+ * by new writes or cluster-wide GC. Node repair can also overwrite them with
+ * the same or a more recent version number, but not with an older version
+ * number.
+ *
+ * - WHITEOUT: for hash table btrees
+ */
+#define BCH_BKEY_TYPES() \
+ x(deleted, 0) \
+ x(whiteout, 1) \
+ x(error, 2) \
+ x(cookie, 3) \
+ x(hash_whiteout, 4) \
+ x(btree_ptr, 5) \
+ x(extent, 6) \
+ x(reservation, 7) \
+ x(inode, 8) \
+ x(inode_generation, 9) \
+ x(dirent, 10) \
+ x(xattr, 11) \
+ x(alloc, 12) \
+ x(quota, 13) \
+ x(stripe, 14) \
+ x(reflink_p, 15) \
+ x(reflink_v, 16) \
+ x(inline_data, 17) \
+ x(btree_ptr_v2, 18) \
+ x(indirect_inline_data, 19) \
+ x(alloc_v2, 20) \
+ x(subvolume, 21) \
+ x(snapshot, 22) \
+ x(inode_v2, 23) \
+ x(alloc_v3, 24) \
+ x(set, 25) \
+ x(lru, 26) \
+ x(alloc_v4, 27) \
+ x(backpointer, 28) \
+ x(inode_v3, 29) \
+ x(bucket_gens, 30) \
+ x(snapshot_tree, 31) \
+ x(logged_op_truncate, 32) \
+ x(logged_op_finsert, 33)
+
+enum bch_bkey_type {
+#define x(name, nr) KEY_TYPE_##name = nr,
+ BCH_BKEY_TYPES()
+#undef x
+ KEY_TYPE_MAX,
+};
+
+struct bch_deleted {
+ struct bch_val v;
+};
+
+struct bch_whiteout {
+ struct bch_val v;
+};
+
+struct bch_error {
+ struct bch_val v;
+};
+
+struct bch_cookie {
+ struct bch_val v;
+ __le64 cookie;
+};
+
+struct bch_hash_whiteout {
+ struct bch_val v;
+};
+
+struct bch_set {
+ struct bch_val v;
+};
+
+/* 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;
+ __le64 seq;
+};
+
+#define BCH_MEMBER_V1_BYTES 56
+
+LE64_BITMASK(BCH_MEMBER_STATE, struct bch_member, flags, 0, 4)
+/* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
+LE64_BITMASK(BCH_MEMBER_DISCARD, struct bch_member, flags, 14, 15)
+LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED, struct bch_member, flags, 15, 20)
+LE64_BITMASK(BCH_MEMBER_GROUP, struct bch_member, flags, 20, 28)
+LE64_BITMASK(BCH_MEMBER_DURABILITY, struct bch_member, flags, 28, 30)
+LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
+ struct bch_member, flags, 30, 31)
+
+#if 0
+LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS, struct bch_member, flags[1], 0, 20);
+LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
+#endif
+
+#define BCH_MEMBER_STATES() \
+ x(rw, 0) \
+ x(ro, 1) \
+ x(failed, 2) \
+ x(spare, 3)
+
+enum bch_member_state {
+#define x(t, n) BCH_MEMBER_STATE_##t = n,
+ BCH_MEMBER_STATES()
+#undef x
+ BCH_MEMBER_STATE_NR
+};
+
+struct bch_sb_field_members_v1 {
+ struct bch_sb_field field;
+ struct bch_member _members[]; //Members are now variable size
+};
+
+struct bch_sb_field_members_v2 {
+ struct bch_sb_field field;
+ __le16 member_bytes; //size of single member entry
+ u8 pad[6];
+ struct bch_member _members[];
+};
+
+/* BCH_SB_FIELD_crypt: */
+
+struct nonce {
+ __le32 d[4];
+};
+
+struct bch_key {
+ __le64 key[4];
+};
+
+#define BCH_KEY_MAGIC \
+ (((__u64) 'b' << 0)|((__u64) 'c' << 8)| \
+ ((__u64) 'h' << 16)|((__u64) '*' << 24)| \
+ ((__u64) '*' << 32)|((__u64) 'k' << 40)| \
+ ((__u64) 'e' << 48)|((__u64) 'y' << 56))
+
+struct bch_encrypted_key {
+ __le64 magic;
+ struct bch_key key;
+};
+
+/*
+ * If this field is present in the superblock, it stores an encryption key which
+ * is used encrypt all other data/metadata. The key will normally be encrypted
+ * with the key userspace provides, but if encryption has been turned off we'll
+ * just store the master key unencrypted in the superblock so we can access the
+ * previously encrypted data.
+ */
+struct bch_sb_field_crypt {
+ struct bch_sb_field field;
+
+ __le64 flags;
+ __le64 kdf_flags;
+ struct bch_encrypted_key key;
+};
+
+LE64_BITMASK(BCH_CRYPT_KDF_TYPE, struct bch_sb_field_crypt, flags, 0, 4);
+
+enum bch_kdf_types {
+ BCH_KDF_SCRYPT = 0,
+ BCH_KDF_NR = 1,
+};
+
+/* stored as base 2 log of scrypt params: */
+LE64_BITMASK(BCH_KDF_SCRYPT_N, struct bch_sb_field_crypt, kdf_flags, 0, 16);
+LE64_BITMASK(BCH_KDF_SCRYPT_R, struct bch_sb_field_crypt, kdf_flags, 16, 32);
+LE64_BITMASK(BCH_KDF_SCRYPT_P, struct bch_sb_field_crypt, kdf_flags, 32, 48);
+
+/* BCH_SB_FIELD_replicas: */
+
+#define BCH_DATA_TYPES() \
+ x(free, 0) \
+ x(sb, 1) \
+ x(journal, 2) \
+ x(btree, 3) \
+ x(user, 4) \
+ x(cached, 5) \
+ x(parity, 6) \
+ x(stripe, 7) \
+ x(need_gc_gens, 8) \
+ x(need_discard, 9)
+
+enum bch_data_type {
+#define x(t, n) BCH_DATA_##t,
+ BCH_DATA_TYPES()
+#undef x
+ BCH_DATA_NR
+};
+
+static inline bool data_type_is_empty(enum bch_data_type type)
+{
+ switch (type) {
+ case BCH_DATA_free:
+ case BCH_DATA_need_gc_gens:
+ case BCH_DATA_need_discard:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static inline bool data_type_is_hidden(enum bch_data_type type)
+{
+ switch (type) {
+ case BCH_DATA_sb:
+ case BCH_DATA_journal:
+ return true;
+ default:
+ return false;
+ }
+}
+
+struct bch_replicas_entry_v0 {
+ __u8 data_type;
+ __u8 nr_devs;
+ __u8 devs[];
+} __packed;
+
+struct bch_sb_field_replicas_v0 {
+ struct bch_sb_field field;
+ struct bch_replicas_entry_v0 entries[];
+} __packed __aligned(8);
+
+struct bch_replicas_entry_v1 {
+ __u8 data_type;
+ __u8 nr_devs;
+ __u8 nr_required;
+ __u8 devs[];
+} __packed;
+
+#define replicas_entry_bytes(_i) \
+ (offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
+
+struct bch_sb_field_replicas {
+ struct bch_sb_field field;
+ struct bch_replicas_entry_v1 entries[];
+} __packed __aligned(8);
+
+/* BCH_SB_FIELD_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) \
+ x(write_buffer_flush_slowpath, 77) \
+ x(write_buffer_flush_sync, 78)
+
+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)
+
+/*
+ * 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))
+
+enum bcachefs_metadata_version {
+ bcachefs_metadata_version_min = 9,
+#define x(t, n) bcachefs_metadata_version_##t = n,
+ BCH_METADATA_VERSIONS()
+#undef x
+ bcachefs_metadata_version_max
+};
+
+static const __maybe_unused
+unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
+
+#define bcachefs_metadata_version_current (bcachefs_metadata_version_max - 1)
+
+#define BCH_SB_SECTOR 8
+#define BCH_SB_MEMBERS_MAX 64 /* XXX kill */
+
+struct bch_sb_layout {
+ __uuid_t magic; /* bcachefs superblock UUID */
+ __u8 layout_type;
+ __u8 sb_max_size_bits; /* base 2 of 512 byte sectors */
+ __u8 nr_superblocks;
+ __u8 pad[5];
+ __le64 sb_offset[61];
+} __packed __aligned(8);
+
+#define BCH_SB_LAYOUT_SECTOR 7
+
+/*
+ * @offset - sector where this sb was written
+ * @version - on disk format version
+ * @version_min - Oldest metadata version this filesystem contains; so we can
+ * safely drop compatibility code and refuse to mount filesystems
+ * we'd need it for
+ * @magic - identifies as a bcachefs superblock (BCHFS_MAGIC)
+ * @seq - incremented each time superblock is written
+ * @uuid - used for generating various magic numbers and identifying
+ * member devices, never changes
+ * @user_uuid - user visible UUID, may be changed
+ * @label - filesystem label
+ * @seq - identifies most recent superblock, incremented each time
+ * superblock is written
+ * @features - enabled incompatible features
+ */
+struct bch_sb {
+ struct bch_csum csum;
+ __le16 version;
+ __le16 version_min;
+ __le16 pad[2];
+ __uuid_t magic;
+ __uuid_t uuid;
+ __uuid_t user_uuid;
+ __u8 label[BCH_SB_LABEL_SIZE];
+ __le64 offset;
+ __le64 seq;
+
+ __le16 block_size;
+ __u8 dev_idx;
+ __u8 nr_devices;
+ __le32 u64s;
+
+ __le64 time_base_lo;
+ __le32 time_base_hi;
+ __le32 time_precision;
+
+ __le64 flags[7];
+ __le64 write_time;
+ __le64 features[2];
+ __le64 compat[2];
+
+ struct bch_sb_layout layout;
+
+ struct bch_sb_field start[0];
+ __le64 _data[];
+} __packed __aligned(8);
+
+/*
+ * Flags:
+ * BCH_SB_INITALIZED - set on first mount
+ * BCH_SB_CLEAN - did we shut down cleanly? Just a hint, doesn't affect
+ * behaviour of mount/recovery path:
+ * BCH_SB_INODE_32BIT - limit inode numbers to 32 bits
+ * BCH_SB_128_BIT_MACS - 128 bit macs instead of 80
+ * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
+ * DATA/META_CSUM_TYPE. Also indicates encryption
+ * algorithm in use, if/when we get more than one
+ */
+
+LE16_BITMASK(BCH_SB_BLOCK_SIZE, struct bch_sb, block_size, 0, 16);
+
+LE64_BITMASK(BCH_SB_INITIALIZED, struct bch_sb, flags[0], 0, 1);
+LE64_BITMASK(BCH_SB_CLEAN, struct bch_sb, flags[0], 1, 2);
+LE64_BITMASK(BCH_SB_CSUM_TYPE, struct bch_sb, flags[0], 2, 8);
+LE64_BITMASK(BCH_SB_ERROR_ACTION, struct bch_sb, flags[0], 8, 12);
+
+LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE, struct bch_sb, flags[0], 12, 28);
+
+LE64_BITMASK(BCH_SB_GC_RESERVE, struct bch_sb, flags[0], 28, 33);
+LE64_BITMASK(BCH_SB_ROOT_RESERVE, struct bch_sb, flags[0], 33, 40);
+
+LE64_BITMASK(BCH_SB_META_CSUM_TYPE, struct bch_sb, flags[0], 40, 44);
+LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE, struct bch_sb, flags[0], 44, 48);
+
+LE64_BITMASK(BCH_SB_META_REPLICAS_WANT, struct bch_sb, flags[0], 48, 52);
+LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT, struct bch_sb, flags[0], 52, 56);
+
+LE64_BITMASK(BCH_SB_POSIX_ACL, struct bch_sb, flags[0], 56, 57);
+LE64_BITMASK(BCH_SB_USRQUOTA, struct bch_sb, flags[0], 57, 58);
+LE64_BITMASK(BCH_SB_GRPQUOTA, struct bch_sb, flags[0], 58, 59);
+LE64_BITMASK(BCH_SB_PRJQUOTA, struct bch_sb, flags[0], 59, 60);
+
+LE64_BITMASK(BCH_SB_HAS_ERRORS, struct bch_sb, flags[0], 60, 61);
+LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
+
+LE64_BITMASK(BCH_SB_BIG_ENDIAN, struct bch_sb, flags[0], 62, 63);
+
+LE64_BITMASK(BCH_SB_STR_HASH_TYPE, struct bch_sb, flags[1], 0, 4);
+LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1], 4, 8);
+LE64_BITMASK(BCH_SB_INODE_32BIT, struct bch_sb, flags[1], 8, 9);
+
+LE64_BITMASK(BCH_SB_128_BIT_MACS, struct bch_sb, flags[1], 9, 10);
+LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE, struct bch_sb, flags[1], 10, 14);
+
+/*
+ * Max size of an extent that may require bouncing to read or write
+ * (checksummed, compressed): 64k
+ */
+LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
+ struct bch_sb, flags[1], 14, 20);
+
+LE64_BITMASK(BCH_SB_META_REPLICAS_REQ, struct bch_sb, flags[1], 20, 24);
+LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ, struct bch_sb, flags[1], 24, 28);
+
+LE64_BITMASK(BCH_SB_PROMOTE_TARGET, struct bch_sb, flags[1], 28, 40);
+LE64_BITMASK(BCH_SB_FOREGROUND_TARGET, struct bch_sb, flags[1], 40, 52);
+LE64_BITMASK(BCH_SB_BACKGROUND_TARGET, struct bch_sb, flags[1], 52, 64);
+
+LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
+ struct bch_sb, flags[2], 0, 4);
+LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES, struct bch_sb, flags[2], 4, 64);
+
+LE64_BITMASK(BCH_SB_ERASURE_CODE, struct bch_sb, flags[3], 0, 16);
+LE64_BITMASK(BCH_SB_METADATA_TARGET, struct bch_sb, flags[3], 16, 28);
+LE64_BITMASK(BCH_SB_SHARD_INUMS, struct bch_sb, flags[3], 28, 29);
+LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
+LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
+LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
+LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
+LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
+LE64_BITMASK(BCH_SB_NOCOW, struct bch_sb, flags[4], 33, 34);
+LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE, struct bch_sb, flags[4], 34, 54);
+LE64_BITMASK(BCH_SB_VERSION_UPGRADE, struct bch_sb, flags[4], 54, 56);
+
+LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
+LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,
+ 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) \
+ x(write_buffer_keys, 11)
+
+enum {
+#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_overwrite:
+ 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 {
+#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);
+
+/*
+ * 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 */
projects / bcachefs-tools-debian / blobdiff