From patchwork Tue May 8 22:17:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kent Overstreet X-Patchwork-Id: 10387671 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7760060353 for ; Tue, 8 May 2018 22:19:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6376328E13 for ; Tue, 8 May 2018 22:19:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 55C4928FFE; Tue, 8 May 2018 22:19:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 501A628E13 for ; Tue, 8 May 2018 22:19:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756104AbeEHWSR (ORCPT ); Tue, 8 May 2018 18:18:17 -0400 Received: from mail-qt0-f180.google.com ([209.85.216.180]:44513 "EHLO mail-qt0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755713AbeEHWSL (ORCPT ); Tue, 8 May 2018 18:18:11 -0400 Received: by mail-qt0-f180.google.com with SMTP id d3-v6so43174346qtp.11; Tue, 08 May 2018 15:18:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=LCDhlhQFFVb5txvUp5xlYCoNPVFNdqrCE7DTsU3P3FA=; b=UWcs/hQQYIGboiLUVgMKOsnzHTQlkaQySsaSASnwnjuia2Bi8s3XvEnjHEZy3DGQgE Dz6P7HkyPVXr3+bxOpTwb+970oIqhmil1bb+9HRqarJKTVC93CHjJ+kmdRlPzcvuOFMr QzyT+FB7tIECEN/oEPoRbKfRigSIPVWP+TDsVhfZ9BW6Xn9lWmROQhDSt6YHXhOkleyg nRjWjRqk42PI6+YtVkS3V5+d0B9/D+D4rP+klZwXkO7hEm68g1OWetIMYXnVxtnwt6Uj 7SqaumxGD250tvIQVk/Q+RGlD8x2a455T0mCdvMS7DF9uaiZL2Pc7m3viLgXW6nGbKLT PHtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=LCDhlhQFFVb5txvUp5xlYCoNPVFNdqrCE7DTsU3P3FA=; b=ZQaQqGskKrBC4Tr+UMRRLEflIWe8D41ti5N9pTJaIvmmQYwZPEIz79WIUveKYsz7JB eB2JMbl251arNKYFmv2SpA/luRnKhM82Ji+0Eq/NheKvZv3jMsapqmjkuALEh1vnkafK 4HGUrhzCSddR8jWAMdtJVRzTIvFQeHYr1dyfb/zuwa7Ib2lzojbMRSH6J7sJWfmV0L/T lf+TzY1WJ73Zz3tQC0xsRvQ51ncC5oyszFcot85RHJQqsf+iMHFvy1Xo5+drF4yhx/1j A6Zyo3BKFWJCqetpM+tqQOplrgpzQO8X2RlJnnidmEj05O+HxbZHXllreIAPETcTMwKa 9/xQ== X-Gm-Message-State: ALQs6tC/VwMXbWAjuJwJCmAuFPrOQqEi0+g2tMVr3ErfeHxQq2HxYopF l+WbWvir419Jc2YPlw4HMYb+0SGmKg== X-Google-Smtp-Source: AB8JxZpe8YNfrp2Am0ZrW5/0+tEANtqsg3wD73Ybv6cXxweJ4pz1ktldqTcBIJRQTv0sWNPIheZuOQ== X-Received: by 2002:a0c:d4c4:: with SMTP id y4-v6mr23601511qvh.239.1525817889134; Tue, 08 May 2018 15:18:09 -0700 (PDT) Received: from localhost.localdomain (c-71-234-172-214.hsd1.vt.comcast.net. [71.234.172.214]) by smtp.gmail.com with ESMTPSA id k188sm19584472qkf.57.2018.05.08.15.18.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 May 2018 15:18:08 -0700 (PDT) From: Kent Overstreet To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org Cc: Kent Overstreet , Dave Chinner , "Darrick J . Wong" , hare@suse.com Subject: [PATCH 1/2] bcachefs: On disk data structures Date: Tue, 8 May 2018 18:17:59 -0400 Message-Id: <20180508221800.2642-2-kent.overstreet@gmail.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180508221800.2642-1-kent.overstreet@gmail.com> References: <20180508221800.2642-1-kent.overstreet@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Kent Overstreet --- fs/bcachefs/bcachefs_format.h | 1448 +++++++++++++++++++++++++++++++++ 1 file changed, 1448 insertions(+) create mode 100644 fs/bcachefs/bcachefs_format.h diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h new file mode 100644 index 0000000000..0961585c7e --- /dev/null +++ b/fs/bcachefs/bcachefs_format.h @@ -0,0 +1,1448 @@ +#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 +#include +#include + +#define LE_BITMASK(_bits, name, type, field, offset, end) \ +static const unsigned name##_OFFSET = offset; \ +static const unsigned name##_BITS = (end - offset); \ +static const __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 */ +#if defined(__LITTLE_ENDIAN) + __u32 snapshot; + __u64 offset; + __u64 inode; +#elif defined(__BIG_ENDIAN) + __u64 inode; + __u64 offset; /* Points to end of extent - sectors */ + __u32 snapshot; +#else +#error edit for your odd byteorder. +#endif +} __attribute__((packed, aligned(4))); + +#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 POS(__u64 inode, __u64 offset) +{ + struct bpos ret; + + ret.inode = inode; + ret.offset = offset; + ret.snapshot = 0; + + return ret; +} + +#define POS_MIN POS(0, 0) +#define POS_MAX POS(KEY_INODE_MAX, KEY_OFFSET_MAX) + +/* Empty placeholder struct, for container_of() */ +struct bch_val { + __u64 __nothing[0]; +}; + +struct bversion { +#if defined(__LITTLE_ENDIAN) + __u64 lo; + __u32 hi; +#elif defined(__BIG_ENDIAN) + __u32 hi; + __u64 lo; +#endif +} __attribute__((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 defined(__LITTLE_ENDIAN) + __u8 pad[1]; + + struct bversion version; + __u32 size; /* extent size, in sectors */ + struct bpos p; +#elif defined(__BIG_ENDIAN) + struct bpos p; + __u32 size; /* extent size, in sectors */ + struct bversion version; + + __u8 pad[1]; +#endif +} __attribute__((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]; +} __attribute__((packed, aligned(8))); + +#define BKEY_U64s (sizeof(struct bkey) / sizeof(__u64)) +#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]; + + union { + struct { + /* Size of combined key and value, in u64s */ + __u8 u64s; + }; + struct { + 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 { struct bkey_i key; __u64 key ## _pad[pad]; } + +#define BKEY_VAL_TYPE(name, nr) \ +struct bkey_i_##name { \ + union { \ + struct bkey k; \ + struct bkey_i k_i; \ + }; \ + struct bch_##name v; \ +} + +/* + * - 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. +*/ +#define KEY_TYPE_DELETED 0 +#define KEY_TYPE_DISCARD 1 +#define KEY_TYPE_ERROR 2 +#define KEY_TYPE_COOKIE 3 +#define KEY_TYPE_PERSISTENT_DISCARD 4 +#define KEY_TYPE_GENERIC_NR 128 + +struct bch_cookie { + struct bch_val v; + __le64 cookie; +}; +BKEY_VAL_TYPE(cookie, KEY_TYPE_COOKIE); + +/* 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 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; +} __attribute__((packed, aligned(8))); + +enum bch_csum_type { + BCH_CSUM_NONE = 0, + BCH_CSUM_CRC32C_NONZERO = 1, + BCH_CSUM_CRC64_NONZERO = 2, + BCH_CSUM_CHACHA20_POLY1305_80 = 3, + BCH_CSUM_CHACHA20_POLY1305_128 = 4, + BCH_CSUM_CRC32C = 5, + BCH_CSUM_CRC64 = 6, + BCH_CSUM_NR = 7, +}; + +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; + } +} + +enum bch_compression_type { + BCH_COMPRESSION_NONE = 0, + BCH_COMPRESSION_LZ4_OLD = 1, + BCH_COMPRESSION_GZIP = 2, + BCH_COMPRESSION_LZ4 = 3, + BCH_COMPRESSION_ZSTD = 4, + BCH_COMPRESSION_NR = 5, +}; + +enum bch_extent_entry_type { + BCH_EXTENT_ENTRY_ptr = 0, + BCH_EXTENT_ENTRY_crc32 = 1, + BCH_EXTENT_ENTRY_crc64 = 2, + BCH_EXTENT_ENTRY_crc128 = 3, +}; + +#define BCH_EXTENT_ENTRY_MAX 4 + +/* 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 +} __attribute__((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; +} __attribute__((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:14, + offset:13, + _uncompressed_size:13, + _compressed_size:13, + type:3; +#endif + struct bch_csum csum; +} __attribute__((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, + erasure_coded:1, + reservation:1, + offset:44, /* 8 petabytes */ + dev:8, + gen:8; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u64 gen:8, + dev:8, + offset:44, + reservation:1, + erasure_coded:1, + cached:1, + type:1; +#endif +} __attribute__((packed, aligned(8))); + +struct bch_extent_reservation { +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u64 type:5, + unused:23, + replicas:4, + generation:32; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u64 generation:32, + replicas:4, + unused:23, + type:5; +#endif +}; + +union bch_extent_entry { +#if defined(__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 + struct bch_extent_crc32 crc32; + struct bch_extent_crc64 crc64; + struct bch_extent_crc128 crc128; + struct bch_extent_ptr ptr; +}; + +enum { + BCH_EXTENT = 128, + + /* + * This is kind of a hack, we're overloading the type for a boolean that + * really should be part of the value - BCH_EXTENT and BCH_EXTENT_CACHED + * have the same value type: + */ + BCH_EXTENT_CACHED = 129, + + /* + * Persistent reservation: + */ + BCH_RESERVATION = 130, +}; + +struct bch_extent { + struct bch_val v; + + union bch_extent_entry start[0]; + __u64 _data[0]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(extent, BCH_EXTENT); + +struct bch_reservation { + struct bch_val v; + + __le32 generation; + __u8 nr_replicas; + __u8 pad[3]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(reservation, BCH_RESERVATION); + +/* 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 \ + (BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1)) + +#define BKEY_PADDED(key) __BKEY_PADDED(key, BKEY_EXTENT_VAL_U64s_MAX) + +/* * 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_extent_ptr)) / sizeof(u64) * BCH_REPLICAS_MAX) +#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 + +enum bch_inode_types { + BCH_INODE_FS = 128, + BCH_INODE_BLOCKDEV = 129, + BCH_INODE_GENERATION = 130, +}; + +struct bch_inode { + struct bch_val v; + + __le64 bi_hash_seed; + __le32 bi_flags; + __le16 bi_mode; + __u8 fields[0]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(inode, BCH_INODE_FS); + +struct bch_inode_generation { + struct bch_val v; + + __le32 bi_generation; + __le32 pad; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(inode_generation, BCH_INODE_GENERATION); + +#define BCH_INODE_FIELDS() \ + BCH_INODE_FIELD(bi_atime, 64) \ + BCH_INODE_FIELD(bi_ctime, 64) \ + BCH_INODE_FIELD(bi_mtime, 64) \ + BCH_INODE_FIELD(bi_otime, 64) \ + BCH_INODE_FIELD(bi_size, 64) \ + BCH_INODE_FIELD(bi_sectors, 64) \ + BCH_INODE_FIELD(bi_uid, 32) \ + BCH_INODE_FIELD(bi_gid, 32) \ + BCH_INODE_FIELD(bi_nlink, 32) \ + BCH_INODE_FIELD(bi_generation, 32) \ + BCH_INODE_FIELD(bi_dev, 32) \ + BCH_INODE_FIELD(bi_data_checksum, 8) \ + BCH_INODE_FIELD(bi_compression, 8) \ + BCH_INODE_FIELD(bi_project, 32) \ + BCH_INODE_FIELD(bi_background_compression, 8) \ + BCH_INODE_FIELD(bi_data_replicas, 8) \ + BCH_INODE_FIELD(bi_promote_target, 16) \ + BCH_INODE_FIELD(bi_foreground_target, 16) \ + BCH_INODE_FIELD(bi_background_target, 16) + +#define BCH_INODE_FIELDS_INHERIT() \ + BCH_INODE_FIELD(bi_data_checksum) \ + BCH_INODE_FIELD(bi_compression) \ + BCH_INODE_FIELD(bi_project) \ + BCH_INODE_FIELD(bi_background_compression) \ + BCH_INODE_FIELD(bi_data_replicas) \ + BCH_INODE_FIELD(bi_promote_target) \ + BCH_INODE_FIELD(bi_foreground_target) \ + BCH_INODE_FIELD(bi_background_target) + +enum { + /* + * User flags (get/settable with FS_IOC_*FLAGS, correspond to FS_*_FL + * flags) + */ + __BCH_INODE_SYNC = 0, + __BCH_INODE_IMMUTABLE = 1, + __BCH_INODE_APPEND = 2, + __BCH_INODE_NODUMP = 3, + __BCH_INODE_NOATIME = 4, + + __BCH_INODE_I_SIZE_DIRTY= 5, + __BCH_INODE_I_SECTORS_DIRTY= 6, + + /* not implemented yet: */ + __BCH_INODE_HAS_XATTRS = 7, /* has xattrs in xattr btree */ + + /* bits 20+ reserved for packed fields below: */ +}; + +#define BCH_INODE_SYNC (1 << __BCH_INODE_SYNC) +#define BCH_INODE_IMMUTABLE (1 << __BCH_INODE_IMMUTABLE) +#define BCH_INODE_APPEND (1 << __BCH_INODE_APPEND) +#define BCH_INODE_NODUMP (1 << __BCH_INODE_NODUMP) +#define BCH_INODE_NOATIME (1 << __BCH_INODE_NOATIME) +#define BCH_INODE_I_SIZE_DIRTY (1 << __BCH_INODE_I_SIZE_DIRTY) +#define BCH_INODE_I_SECTORS_DIRTY (1 << __BCH_INODE_I_SECTORS_DIRTY) +#define BCH_INODE_HAS_XATTRS (1 << __BCH_INODE_HAS_XATTRS) + +LE32_BITMASK(INODE_STR_HASH, struct bch_inode, bi_flags, 20, 24); +LE32_BITMASK(INODE_NR_FIELDS, struct bch_inode, bi_flags, 24, 32); + +struct bch_inode_blockdev { + struct bch_val v; + + __le64 i_size; + __le64 i_flags; + + /* Seconds: */ + __le64 i_ctime; + __le64 i_mtime; + + uuid_le i_uuid; + __u8 i_label[32]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(inode_blockdev, BCH_INODE_BLOCKDEV); + +/* Thin provisioned volume, or cache for another block device? */ +LE64_BITMASK(CACHED_DEV, struct bch_inode_blockdev, i_flags, 0, 1) + +/* 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: + */ + +enum { + BCH_DIRENT = 128, + BCH_DIRENT_WHITEOUT = 129, +}; + +struct bch_dirent { + struct bch_val v; + + /* Target inode number: */ + __le64 d_inum; + + /* + * 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[]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(dirent, BCH_DIRENT); + +/* Xattrs */ + +enum { + BCH_XATTR = 128, + BCH_XATTR_WHITEOUT = 129, +}; + +#define BCH_XATTR_INDEX_USER 0 +#define BCH_XATTR_INDEX_POSIX_ACL_ACCESS 1 +#define BCH_XATTR_INDEX_POSIX_ACL_DEFAULT 2 +#define BCH_XATTR_INDEX_TRUSTED 3 +#define BCH_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[]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(xattr, BCH_XATTR); + +/* Bucket/allocation information: */ + +enum { + BCH_ALLOC = 128, +}; + +enum { + BCH_ALLOC_FIELD_READ_TIME = 0, + BCH_ALLOC_FIELD_WRITE_TIME = 1, +}; + +struct bch_alloc { + struct bch_val v; + __u8 fields; + __u8 gen; + __u8 data[]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(alloc, BCH_ALLOC); + +/* Quotas: */ + +enum { + BCH_QUOTA = 128, +}; + +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]; +} __attribute__((packed, aligned(8))); +BKEY_VAL_TYPE(quota, BCH_QUOTA); + +/* 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, 1) \ + x(crypt, 2) \ + x(replicas, 3) \ + x(quota, 4) \ + x(disk_groups, 5) + +enum bch_sb_field_type { +#define x(f, nr) BCH_SB_FIELD_##f = nr, + BCH_SB_FIELDS() +#undef x + BCH_SB_FIELD_NR +}; + +/* BCH_SB_FIELD_journal: */ + +struct bch_sb_field_journal { + struct bch_sb_field field; + __le64 buckets[0]; +}; + +/* BCH_SB_FIELD_members: */ + +struct bch_member { + uuid_le 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[2]; +}; + +LE64_BITMASK(BCH_MEMBER_STATE, struct bch_member, flags[0], 0, 4) +/* 4-10 unused, was TIER, HAS_(META)DATA */ +LE64_BITMASK(BCH_MEMBER_REPLACEMENT, struct bch_member, flags[0], 10, 14) +LE64_BITMASK(BCH_MEMBER_DISCARD, struct bch_member, flags[0], 14, 15) +LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED, struct bch_member, flags[0], 15, 20) +LE64_BITMASK(BCH_MEMBER_GROUP, struct bch_member, flags[0], 20, 28) +LE64_BITMASK(BCH_MEMBER_DURABILITY, struct bch_member, flags[0], 28, 30) + +#define BCH_TIER_MAX 4U + +#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 + +enum bch_member_state { + BCH_MEMBER_STATE_RW = 0, + BCH_MEMBER_STATE_RO = 1, + BCH_MEMBER_STATE_FAILED = 2, + BCH_MEMBER_STATE_SPARE = 3, + BCH_MEMBER_STATE_NR = 4, +}; + +enum cache_replacement { + CACHE_REPLACEMENT_LRU = 0, + CACHE_REPLACEMENT_FIFO = 1, + CACHE_REPLACEMENT_RANDOM = 2, + CACHE_REPLACEMENT_NR = 3, +}; + +struct bch_sb_field_members { + struct bch_sb_field field; + struct bch_member members[0]; +}; + +/* 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: */ + +enum bch_data_type { + BCH_DATA_NONE = 0, + BCH_DATA_SB = 1, + BCH_DATA_JOURNAL = 2, + BCH_DATA_BTREE = 3, + BCH_DATA_USER = 4, + BCH_DATA_CACHED = 5, + BCH_DATA_NR = 6, +}; + +struct bch_replicas_entry { + u8 data_type; + u8 nr; + u8 devs[0]; +}; + +struct bch_sb_field_replicas { + struct bch_sb_field field; + struct bch_replicas_entry entries[0]; +}; + +/* 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]; +} __attribute__((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]; +}; + +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[0]; +}; + +/* Superblock: */ + +/* + * Version 8: BCH_SB_ENCODED_EXTENT_MAX_BITS + * BCH_MEMBER_DATA_ALLOWED + * Version 9: incompatible extent nonce change + */ + +#define BCH_SB_VERSION_MIN 7 +#define BCH_SB_VERSION_EXTENT_MAX 8 +#define BCH_SB_VERSION_EXTENT_NONCE_V1 9 +#define BCH_SB_VERSION_MAX 9 + +#define BCH_SB_SECTOR 8 +#define BCH_SB_MEMBERS_MAX 64 /* XXX kill */ + +struct bch_sb_layout { + uuid_le 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]; +} __attribute__((packed, aligned(8))); + +#define BCH_SB_LAYOUT_SECTOR 7 + +/* + * @offset - sector where this sb was written + * @version - on disk format version + * @magic - identifies as a bcachefs superblock (BCACHE_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; + __le64 version; + uuid_le magic; + uuid_le uuid; + uuid_le 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; + + union { + struct bch_sb_field start[0]; + __le64 _data[0]; + }; +} __attribute__((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); + +/* 60-64 unused */ + +LE64_BITMASK(BCH_SB_STR_HASH_TYPE, struct bch_sb, flags[1], 0, 4); +LE64_BITMASK(BCH_SB_COMPRESSION_TYPE, 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, + struct bch_sb, flags[2], 0, 4); + +/* Features: */ +enum bch_sb_features { + BCH_FEATURE_LZ4 = 0, + BCH_FEATURE_GZIP = 1, + BCH_FEATURE_ZSTD = 2, +}; + +/* options: */ + +#define BCH_REPLICAS_MAX 4U + +enum bch_error_actions { + BCH_ON_ERROR_CONTINUE = 0, + BCH_ON_ERROR_RO = 1, + BCH_ON_ERROR_PANIC = 2, + BCH_NR_ERROR_ACTIONS = 3, +}; + +enum bch_csum_opts { + BCH_CSUM_OPT_NONE = 0, + BCH_CSUM_OPT_CRC32C = 1, + BCH_CSUM_OPT_CRC64 = 2, + BCH_CSUM_OPT_NR = 3, +}; + +enum bch_str_hash_opts { + BCH_STR_HASH_CRC32C = 0, + BCH_STR_HASH_CRC64 = 1, + BCH_STR_HASH_SIPHASH = 2, + BCH_STR_HASH_NR = 3, +}; + +#define BCH_COMPRESSION_TYPES() \ + x(NONE) \ + x(LZ4) \ + x(GZIP) \ + x(ZSTD) + +enum bch_compression_opts { +#define x(t) BCH_COMPRESSION_OPT_##t, + BCH_COMPRESSION_TYPES() +#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_LE(0xf67385c6, 0x1a4e, 0xca45, \ + 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81) + +#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 BCACHE_JSET_VERSION_UUIDv1 1 +#define BCACHE_JSET_VERSION_UUID 1 /* Always latest UUID format */ +#define BCACHE_JSET_VERSION_JKEYS 2 +#define BCACHE_JSET_VERSION 2 + +struct jset_entry { + __le16 u64s; + __u8 btree_id; + __u8 level; + __u8 type; /* designates what this jset holds */ + __u8 pad[3]; + + union { + struct bkey_i start[0]; + __u64 _data[0]; + }; +}; + +#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) + +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; +}; + +/* + * 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; + __le16 write_clock; + + /* Sequence number of oldest dirty journal entry */ + __le64 last_seq; + + + union { + struct jset_entry start[0]; + __u64 _data[0]; + }; +} __attribute__((packed, aligned(8))); + +LE32_BITMASK(JSET_CSUM_TYPE, struct jset, flags, 0, 4); +LE32_BITMASK(JSET_BIG_ENDIAN, struct jset, flags, 4, 5); + +#define BCH_JOURNAL_BUCKETS_MIN 20 + +/* Btree: */ + +#define DEFINE_BCH_BTREE_IDS() \ + DEF_BTREE_ID(EXTENTS, 0, "extents") \ + DEF_BTREE_ID(INODES, 1, "inodes") \ + DEF_BTREE_ID(DIRENTS, 2, "dirents") \ + DEF_BTREE_ID(XATTRS, 3, "xattrs") \ + DEF_BTREE_ID(ALLOC, 4, "alloc") \ + DEF_BTREE_ID(QUOTAS, 5, "quotas") + +#define DEF_BTREE_ID(kwd, val, name) BTREE_ID_##kwd = val, + +enum btree_id { + DEFINE_BCH_BTREE_IDS() + BTREE_ID_NR +}; + +#undef DEF_BTREE_ID + +#define BTREE_MAX_DEPTH 4U + +/* Btree nodes */ + +/* Version 1: Seed pointer into btree node checksum + */ +#define BCACHE_BSET_CSUM 1 +#define BCACHE_BSET_KEY_v1 2 +#define BCACHE_BSET_JOURNAL_SEQ 3 +#define BCACHE_BSET_VERSION 3 + +/* + * 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 */ + + union { + struct bkey_packed start[0]; + __u64 _data[0]; + }; +} __attribute__((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); + +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; + struct bkey_format format; + + union { + struct bset keys; + struct { + __u8 pad[22]; + __le16 u64s; + __u64 _data[0]; + + }; + }; +} __attribute__((packed, aligned(8))); + +LE64_BITMASK(BTREE_NODE_ID, struct btree_node, flags, 0, 4); +LE64_BITMASK(BTREE_NODE_LEVEL, struct btree_node, flags, 4, 8); +/* 8-32 unused */ +LE64_BITMASK(BTREE_NODE_SEQ, struct btree_node, flags, 32, 64); + +struct btree_node_entry { + struct bch_csum csum; + + union { + struct bset keys; + struct { + __u8 pad[22]; + __le16 u64s; + __u64 _data[0]; + + }; + }; +} __attribute__((packed, aligned(8))); + +#endif /* _BCACHEFS_FORMAT_H */