diff options
| -rw-r--r-- | fs/bcachefs/bcachefs_format.h | 281 | ||||
| -rw-r--r-- | fs/bcachefs/extents_format.h | 282 |
2 files changed, 284 insertions, 279 deletions
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h index 5327514d96f9..2921ecd49c6e 100644 --- a/fs/bcachefs/bcachefs_format.h +++ b/fs/bcachefs/bcachefs_format.h @@ -417,272 +417,12 @@ 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; @@ -691,25 +431,6 @@ struct bch_reservation { __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) - struct bch_backpointer { struct bch_val v; __u8 btree_id; @@ -720,6 +441,8 @@ struct bch_backpointer { struct bpos pos; } __packed __aligned(8); +#include "extents_format.h" + /* Reflink: */ struct bch_reflink_p { diff --git a/fs/bcachefs/extents_format.h b/fs/bcachefs/extents_format.h new file mode 100644 index 000000000000..939d09f9d3b8 --- /dev/null +++ b/fs/bcachefs/extents_format.h @@ -0,0 +1,282 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHEFS_EXTENTS_FORMAT_H +#define _BCACHEFS_EXTENTS_FORMAT_H + +/* + * 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. + */ + +#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); + +/* 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) + +#endif /* _BCACHEFS_EXTENTS_FORMAT_H */ |