From 2a9dc7a8fec6ca287e2c038f9441e24269e10b5f Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Fri, 20 Aug 2021 18:00:18 +0800 Subject: erofs: introduce chunk-based file on-disk format Currently, uncompressed data except for tail-packing inline is consecutive on disk. In order to support chunk-based data deduplication, add a new corresponding inode data layout. In the future, the data source of chunks can be either (un)compressed. Link: https://lore.kernel.org/r/20210820100019.208490-1-hsiangkao@linux.alibaba.com Reviewed-by: Liu Bo Reviewed-by: Chao Yu Signed-off-by: Gao Xiang --- fs/erofs/erofs_fs.h | 47 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 45 insertions(+), 2 deletions(-) (limited to 'fs/erofs/erofs_fs.h') diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index 0f8da74570b4..b0b23f41abc3 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -4,6 +4,7 @@ * * Copyright (C) 2017-2018 HUAWEI, Inc. * https://www.huawei.com/ + * Copyright (C) 2021, Alibaba Cloud */ #ifndef __EROFS_FS_H #define __EROFS_FS_H @@ -19,10 +20,12 @@ #define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001 #define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002 #define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER 0x00000002 +#define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE 0x00000004 #define EROFS_ALL_FEATURE_INCOMPAT \ (EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \ EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \ - EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER) + EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \ + EROFS_FEATURE_INCOMPAT_CHUNKED_FILE) #define EROFS_SB_EXTSLOT_SIZE 16 @@ -64,13 +67,16 @@ struct erofs_super_block { * inode, [xattrs], last_inline_data, ... | ... | no-holed data * 3 - inode compression D: * inode, [xattrs], map_header, extents ... | ... - * 4~7 - reserved + * 4 - inode chunk-based E: + * inode, [xattrs], chunk indexes ... | ... + * 5~7 - reserved */ enum { EROFS_INODE_FLAT_PLAIN = 0, EROFS_INODE_FLAT_COMPRESSION_LEGACY = 1, EROFS_INODE_FLAT_INLINE = 2, EROFS_INODE_FLAT_COMPRESSION = 3, + EROFS_INODE_CHUNK_BASED = 4, EROFS_INODE_DATALAYOUT_MAX }; @@ -90,6 +96,19 @@ static inline bool erofs_inode_is_data_compressed(unsigned int datamode) #define EROFS_I_ALL \ ((1 << (EROFS_I_DATALAYOUT_BIT + EROFS_I_DATALAYOUT_BITS)) - 1) +/* indicate chunk blkbits, thus 'chunksize = blocksize << chunk blkbits' */ +#define EROFS_CHUNK_FORMAT_BLKBITS_MASK 0x001F +/* with chunk indexes or just a 4-byte blkaddr array */ +#define EROFS_CHUNK_FORMAT_INDEXES 0x0020 + +#define EROFS_CHUNK_FORMAT_ALL \ + (EROFS_CHUNK_FORMAT_BLKBITS_MASK | EROFS_CHUNK_FORMAT_INDEXES) + +struct erofs_inode_chunk_info { + __le16 format; /* chunk blkbits, etc. */ + __le16 reserved; +}; + /* 32-byte reduced form of an ondisk inode */ struct erofs_inode_compact { __le16 i_format; /* inode format hints */ @@ -107,6 +126,9 @@ struct erofs_inode_compact { /* for device files, used to indicate old/new device # */ __le32 rdev; + + /* for chunk-based files, it contains the summary info */ + struct erofs_inode_chunk_info c; } i_u; __le32 i_ino; /* only used for 32-bit stat compatibility */ __le16 i_uid; @@ -135,6 +157,9 @@ struct erofs_inode_extended { /* for device files, used to indicate old/new device # */ __le32 rdev; + + /* for chunk-based files, it contains the summary info */ + struct erofs_inode_chunk_info c; } i_u; /* only used for 32-bit stat compatibility */ @@ -204,6 +229,19 @@ static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e) e->e_name_len + le16_to_cpu(e->e_value_size)); } +/* represent a zeroed chunk (hole) */ +#define EROFS_NULL_ADDR -1 + +/* 4-byte block address array */ +#define EROFS_BLOCK_MAP_ENTRY_SIZE sizeof(__le32) + +/* 8-byte inode chunk indexes */ +struct erofs_inode_chunk_index { + __le16 advise; /* always 0, don't care for now */ + __le16 device_id; /* back-end storage id, always 0 for now */ + __le32 blkaddr; /* start block address of this inode chunk */ +}; + /* maximum supported size of a physical compression cluster */ #define Z_EROFS_PCLUSTER_MAX_SIZE (1024 * 1024) @@ -338,9 +376,14 @@ static inline void erofs_check_ondisk_layout_definitions(void) BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64); BUILD_BUG_ON(sizeof(struct erofs_xattr_ibody_header) != 12); BUILD_BUG_ON(sizeof(struct erofs_xattr_entry) != 4); + BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_info) != 4); + BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) != 8); BUILD_BUG_ON(sizeof(struct z_erofs_map_header) != 8); BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8); BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12); + /* keep in sync between 2 index structures for better extendibility */ + BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) != + sizeof(struct z_erofs_vle_decompressed_index)); BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) < Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1); -- cgit v1.2.3