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b15b2e307c
linux/fs/erofs/erofs_fs.h
Yue Hu b15b2e307c erofs: support on-disk compressed fragments data 
Introduce on-disk compressed fragments data feature.

This approach adds a new field called `h_fragmentoff' in the per-file
compression header to indicate the fragment offset of each tail pcluster
or the whole file in the special packed inode.

Similar to ztailpacking, it will also find and record the 'headlcn'
of the tail pcluster when initializing per-inode zmap for making
follow-on requests more easy.

Signed-off-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/YzHKxcFTlHGgXeH9@B-P7TQMD6M-0146.local
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2022-09-26 23:55:39 +08:00

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/* SPDX-License-Identifier: GPL-2.0-only OR Apache-2.0 */
/*
* EROFS (Enhanced ROM File System) on-disk format definition
*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Copyright (C) 2021, Alibaba Cloud
*/
#ifndef __EROFS_FS_H
#define __EROFS_FS_H
#define EROFS_SUPER_OFFSET 1024
#define EROFS_FEATURE_COMPAT_SB_CHKSUM 0x00000001
#define EROFS_FEATURE_COMPAT_MTIME 0x00000002
/*
* Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
* be incompatible with this kernel version.
*/
#define EROFS_FEATURE_INCOMPAT_ZERO_PADDING 0x00000001
#define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002
#define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER 0x00000002
#define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE 0x00000004
#define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE 0x00000008
#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 0x00000008
#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING 0x00000010
#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
#define EROFS_ALL_FEATURE_INCOMPAT \
(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \
EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
EROFS_FEATURE_INCOMPAT_DEVICE_TABLE | \
EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
EROFS_FEATURE_INCOMPAT_FRAGMENTS)
#define EROFS_SB_EXTSLOT_SIZE 16
struct erofs_deviceslot {
u8 tag[64]; /* digest(sha256), etc. */
__le32 blocks; /* total fs blocks of this device */
__le32 mapped_blkaddr; /* map starting at mapped_blkaddr */
u8 reserved[56];
};
#define EROFS_DEVT_SLOT_SIZE sizeof(struct erofs_deviceslot)
/* erofs on-disk super block (currently 128 bytes) */
struct erofs_super_block {
__le32 magic; /* file system magic number */
__le32 checksum; /* crc32c(super_block) */
__le32 feature_compat;
__u8 blkszbits; /* support block_size == PAGE_SIZE only */
__u8 sb_extslots; /* superblock size = 128 + sb_extslots * 16 */
__le16 root_nid; /* nid of root directory */
__le64 inos; /* total valid ino # (== f_files - f_favail) */
__le64 build_time; /* compact inode time derivation */
__le32 build_time_nsec; /* compact inode time derivation in ns scale */
__le32 blocks; /* used for statfs */
__le32 meta_blkaddr; /* start block address of metadata area */
__le32 xattr_blkaddr; /* start block address of shared xattr area */
__u8 uuid[16]; /* 128-bit uuid for volume */
__u8 volume_name[16]; /* volume name */
__le32 feature_incompat;
union {
/* bitmap for available compression algorithms */
__le16 available_compr_algs;
/* customized sliding window size instead of 64k by default */
__le16 lz4_max_distance;
} __packed u1;
__le16 extra_devices; /* # of devices besides the primary device */
__le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */
__u8 reserved[6];
__le64 packed_nid; /* nid of the special packed inode */
__u8 reserved2[24];
};
/*
* erofs inode datalayout (i_format in on-disk inode):
* 0 - uncompressed flat inode without tail-packing inline data:
* inode, [xattrs], ... | ... | no-holed data
* 1 - compressed inode with non-compact indexes:
* inode, [xattrs], [map_header], extents ... | ...
* 2 - uncompressed flat inode with tail-packing inline data:
* inode, [xattrs], tailpacking data, ... | ... | no-holed data
* 3 - compressed inode with compact indexes:
* inode, [xattrs], map_header, extents ... | ...
* 4 - chunk-based inode with (optional) multi-device support:
* 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
};
static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
{
return datamode == EROFS_INODE_FLAT_COMPRESSION ||
datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY;
}
/* bit definitions of inode i_format */
#define EROFS_I_VERSION_BITS 1
#define EROFS_I_DATALAYOUT_BITS 3
#define EROFS_I_VERSION_BIT 0
#define EROFS_I_DATALAYOUT_BIT 1
#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 */
/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
__le16 i_xattr_icount;
__le16 i_mode;
__le16 i_nlink;
__le32 i_size;
__le32 i_reserved;
union {
/* total compressed blocks for compressed inodes */
__le32 compressed_blocks;
/* block address for uncompressed flat inodes */
__le32 raw_blkaddr;
/* 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;
__le16 i_gid;
__le32 i_reserved2;
};
/* 32-byte on-disk inode */
#define EROFS_INODE_LAYOUT_COMPACT 0
/* 64-byte on-disk inode */
#define EROFS_INODE_LAYOUT_EXTENDED 1
/* 64-byte complete form of an ondisk inode */
struct erofs_inode_extended {
__le16 i_format; /* inode format hints */
/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
__le16 i_xattr_icount;
__le16 i_mode;
__le16 i_reserved;
__le64 i_size;
union {
/* total compressed blocks for compressed inodes */
__le32 compressed_blocks;
/* block address for uncompressed flat inodes */
__le32 raw_blkaddr;
/* 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 */
__le32 i_ino;
__le32 i_uid;
__le32 i_gid;
__le64 i_mtime;
__le32 i_mtime_nsec;
__le32 i_nlink;
__u8 i_reserved2[16];
};
#define EROFS_MAX_SHARED_XATTRS (128)
/* h_shared_count between 129 ... 255 are special # */
#define EROFS_SHARED_XATTR_EXTENT (255)
/*
* inline xattrs (n == i_xattr_icount):
* erofs_xattr_ibody_header(1) + (n - 1) * 4 bytes
* 12 bytes / \
* / \
* /-----------------------\
* | erofs_xattr_entries+ |
* +-----------------------+
* inline xattrs must starts in erofs_xattr_ibody_header,
* for read-only fs, no need to introduce h_refcount
*/
struct erofs_xattr_ibody_header {
__le32 h_reserved;
__u8 h_shared_count;
__u8 h_reserved2[7];
__le32 h_shared_xattrs[]; /* shared xattr id array */
};
/* Name indexes */
#define EROFS_XATTR_INDEX_USER 1
#define EROFS_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EROFS_XATTR_INDEX_TRUSTED 4
#define EROFS_XATTR_INDEX_LUSTRE 5
#define EROFS_XATTR_INDEX_SECURITY 6
/* xattr entry (for both inline & shared xattrs) */
struct erofs_xattr_entry {
__u8 e_name_len; /* length of name */
__u8 e_name_index; /* attribute name index */
__le16 e_value_size; /* size of attribute value */
/* followed by e_name and e_value */
char e_name[]; /* attribute name */
};
static inline unsigned int erofs_xattr_ibody_size(__le16 i_xattr_icount)
{
if (!i_xattr_icount)
return 0;
return sizeof(struct erofs_xattr_ibody_header) +
sizeof(__u32) * (le16_to_cpu(i_xattr_icount) - 1);
}
#define EROFS_XATTR_ALIGN(size) round_up(size, sizeof(struct erofs_xattr_entry))
static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e)
{
return EROFS_XATTR_ALIGN(sizeof(struct erofs_xattr_entry) +
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 (with bits masked) */
__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)
/* available compression algorithm types (for h_algorithmtype) */
enum {
Z_EROFS_COMPRESSION_LZ4 = 0,
Z_EROFS_COMPRESSION_LZMA = 1,
Z_EROFS_COMPRESSION_MAX
};
#define Z_EROFS_ALL_COMPR_ALGS ((1 << Z_EROFS_COMPRESSION_MAX) - 1)
/* 14 bytes (+ length field = 16 bytes) */
struct z_erofs_lz4_cfgs {
__le16 max_distance;
__le16 max_pclusterblks;
u8 reserved[10];
} __packed;
/* 14 bytes (+ length field = 16 bytes) */
struct z_erofs_lzma_cfgs {
__le32 dict_size;
__le16 format;
u8 reserved[8];
} __packed;
#define Z_EROFS_LZMA_MAX_DICT_SIZE (8 * Z_EROFS_PCLUSTER_MAX_SIZE)
/*
* bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
* e.g. for 4k logical cluster size, 4B if compacted 2B is off;
* (4B) + 2B + (4B) if compacted 2B is on.
* bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
* bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
* bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
* bit 4 : interlaced plain pcluster (0 - off; 1 - on)
* bit 5 : fragment pcluster (0 - off; 1 - on)
*/
#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010
#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER 0x0020
#define Z_EROFS_FRAGMENT_INODE_BIT 7
struct z_erofs_map_header {
union {
/* fragment data offset in the packed inode */
__le32 h_fragmentoff;
struct {
__le16 h_reserved1;
/* indicates the encoded size of tailpacking data */
__le16 h_idata_size;
};
};
__le16 h_advise;
/*
* bit 0-3 : algorithm type of head 1 (logical cluster type 01);
* bit 4-7 : algorithm type of head 2 (logical cluster type 11).
*/
__u8 h_algorithmtype;
/*
* bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
* bit 3-6 : reserved;
* bit 7 : move the whole file into packed inode or not.
*/
__u8 h_clusterbits;
};
#define Z_EROFS_VLE_LEGACY_HEADER_PADDING 8
/*
* Fixed-sized output compression on-disk logical cluster type:
* 0 - literal (uncompressed) lcluster
* 1,3 - compressed lcluster (for HEAD lclusters)
* 2 - compressed lcluster (for NONHEAD lclusters)
*
* In detail,
* 0 - literal (uncompressed) lcluster,
* di_advise = 0
* di_clusterofs = the literal data offset of the lcluster
* di_blkaddr = the blkaddr of the literal pcluster
*
* 1,3 - compressed lcluster (for HEAD lclusters)
* di_advise = 1 or 3
* di_clusterofs = the decompressed data offset of the lcluster
* di_blkaddr = the blkaddr of the compressed pcluster
*
* 2 - compressed lcluster (for NONHEAD lclusters)
* di_advise = 2
* di_clusterofs =
* the decompressed data offset in its own HEAD lcluster
* di_u.delta[0] = distance to this HEAD lcluster
* di_u.delta[1] = distance to the next HEAD lcluster
*/
enum {
Z_EROFS_VLE_CLUSTER_TYPE_PLAIN = 0,
Z_EROFS_VLE_CLUSTER_TYPE_HEAD1 = 1,
Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD = 2,
Z_EROFS_VLE_CLUSTER_TYPE_HEAD2 = 3,
Z_EROFS_VLE_CLUSTER_TYPE_MAX
};
#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS 2
#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT 0
/*
* D0_CBLKCNT will be marked _only_ at the 1st non-head lcluster to store the
* compressed block count of a compressed extent (in logical clusters, aka.
* block count of a pcluster).
*/
#define Z_EROFS_VLE_DI_D0_CBLKCNT (1 << 11)
struct z_erofs_vle_decompressed_index {
__le16 di_advise;
/* where to decompress in the head lcluster */
__le16 di_clusterofs;
union {
/* for the HEAD lclusters */
__le32 blkaddr;
/*
* for the NONHEAD lclusters
* [0] - distance to its HEAD lcluster
* [1] - distance to the next HEAD lcluster
*/
__le16 delta[2];
} di_u;
};
#define Z_EROFS_VLE_LEGACY_INDEX_ALIGN(size) \
(round_up(size, sizeof(struct z_erofs_vle_decompressed_index)) + \
sizeof(struct z_erofs_map_header) + Z_EROFS_VLE_LEGACY_HEADER_PADDING)
/* dirent sorts in alphabet order, thus we can do binary search */
struct erofs_dirent {
__le64 nid; /* node number */
__le16 nameoff; /* start offset of file name */
__u8 file_type; /* file type */
__u8 reserved; /* reserved */
} __packed;
/*
* EROFS file types should match generic FT_* types and
* it seems no need to add BUILD_BUG_ONs since potential
* unmatchness will break other fses as well...
*/
#define EROFS_NAME_LEN 255
/* check the EROFS on-disk layout strictly at compile time */
static inline void erofs_check_ondisk_layout_definitions(void)
{
const __le64 fmh = *(__le64 *)&(struct z_erofs_map_header) {
.h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
};
BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
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(sizeof(struct erofs_deviceslot) != 128);
BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
/* exclude old compiler versions like gcc 7.5.0 */
BUILD_BUG_ON(__builtin_constant_p(fmh) ?
fmh != cpu_to_le64(1ULL << 63) : 0);
}
#endif
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