324 lines
9.6 KiB
C
Executable file
324 lines
9.6 KiB
C
Executable file
/* 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.
|
|
* http://www.huawei.com/
|
|
* Created by Gao Xiang <gaoxiang25@huawei.com>
|
|
*/
|
|
#ifndef __EROFS_FS_H
|
|
#define __EROFS_FS_H
|
|
|
|
#define EROFS_SUPER_OFFSET 1024
|
|
|
|
/*
|
|
* Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
|
|
* be incompatible with this kernel version.
|
|
*/
|
|
#define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001
|
|
#define EROFS_ALL_FEATURE_INCOMPAT EROFS_FEATURE_INCOMPAT_LZ4_0PADDING
|
|
|
|
/* 128-byte erofs on-disk super block */
|
|
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 reserved;
|
|
|
|
__le16 root_nid; /* nid of root directory */
|
|
__le64 inos; /* total valid ino # (== f_files - f_favail) */
|
|
|
|
__le64 build_time; /* inode v1 time derivation */
|
|
__le32 build_time_nsec; /* inode v1 time derivation in nano 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;
|
|
|
|
__u8 reserved2[44];
|
|
};
|
|
|
|
/*
|
|
* erofs inode datalayout (i_format in on-disk inode):
|
|
* 0 - inode plain without inline data A:
|
|
* inode, [xattrs], ... | ... | no-holed data
|
|
* 1 - inode VLE compression B (legacy):
|
|
* inode, [xattrs], extents ... | ...
|
|
* 2 - inode plain with inline data C:
|
|
* inode, [xattrs], last_inline_data, ... | ... | no-holed data
|
|
* 3 - inode compression D:
|
|
* inode, [xattrs], map_header, extents ... | ...
|
|
* 4~7 - 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_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_advise */
|
|
#define EROFS_I_VERSION_BITS 1
|
|
#define EROFS_I_DATALAYOUT_BITS 3
|
|
|
|
#define EROFS_I_VERSION_BIT 0
|
|
#define EROFS_I_DATALAYOUT_BIT 1
|
|
|
|
/* 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 {
|
|
/* file total compressed blocks for data mapping 1 */
|
|
__le32 compressed_blocks;
|
|
__le32 raw_blkaddr;
|
|
|
|
/* for device files, used to indicate old/new device # */
|
|
__le32 rdev;
|
|
} i_u;
|
|
__le32 i_ino; /* only used for 32-bit stat compatibility */
|
|
__le16 i_uid;
|
|
__le16 i_gid;
|
|
__le32 i_reserved2;
|
|
};
|
|
|
|
/* 32 bytes on-disk inode */
|
|
#define EROFS_INODE_LAYOUT_COMPACT 0
|
|
/* 64 bytes 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 {
|
|
/* file total compressed blocks for data mapping 1 */
|
|
__le32 compressed_blocks;
|
|
__le32 raw_blkaddr;
|
|
|
|
/* for device files, used to indicate old/new device # */
|
|
__le32 rdev;
|
|
} i_u;
|
|
|
|
/* only used for 32-bit stat compatibility */
|
|
__le32 i_ino;
|
|
|
|
__le32 i_uid;
|
|
__le32 i_gid;
|
|
__le64 i_ctime;
|
|
__le32 i_ctime_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[0]; /* 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[0]; /* 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));
|
|
}
|
|
|
|
/* available compression algorithm types (for h_algorithmtype) */
|
|
enum {
|
|
Z_EROFS_COMPRESSION_LZ4 = 0,
|
|
Z_EROFS_COMPRESSION_MAX
|
|
};
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
#define Z_EROFS_ADVISE_COMPACTED_2B_BIT 0
|
|
|
|
#define Z_EROFS_ADVISE_COMPACTED_2B (1 << Z_EROFS_ADVISE_COMPACTED_2B_BIT)
|
|
|
|
struct z_erofs_map_header {
|
|
__le32 h_reserved1;
|
|
__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 3-4 : (physical - logical) cluster bits of head 1:
|
|
* For example, if logical clustersize = 4096, 1 for 8192.
|
|
* bit 5-7 : (physical - logical) cluster bits of head 2.
|
|
*/
|
|
__u8 h_clusterbits;
|
|
};
|
|
|
|
#define Z_EROFS_VLE_LEGACY_HEADER_PADDING 8
|
|
|
|
/*
|
|
* Fixed-sized output compression ondisk Logical Extent cluster type:
|
|
* 0 - literal (uncompressed) cluster
|
|
* 1 - compressed cluster (for the head logical cluster)
|
|
* 2 - compressed cluster (for the other logical clusters)
|
|
*
|
|
* In detail,
|
|
* 0 - literal (uncompressed) cluster,
|
|
* di_advise = 0
|
|
* di_clusterofs = the literal data offset of the cluster
|
|
* di_blkaddr = the blkaddr of the literal cluster
|
|
*
|
|
* 1 - compressed cluster (for the head logical cluster)
|
|
* di_advise = 1
|
|
* di_clusterofs = the decompressed data offset of the cluster
|
|
* di_blkaddr = the blkaddr of the compressed cluster
|
|
*
|
|
* 2 - compressed cluster (for the other logical clusters)
|
|
* di_advise = 2
|
|
* di_clusterofs =
|
|
* the decompressed data offset in its own head cluster
|
|
* di_u.delta[0] = distance to its corresponding head cluster
|
|
* di_u.delta[1] = distance to its corresponding tail cluster
|
|
* (di_advise could be 0, 1 or 2)
|
|
*/
|
|
enum {
|
|
Z_EROFS_VLE_CLUSTER_TYPE_PLAIN = 0,
|
|
Z_EROFS_VLE_CLUSTER_TYPE_HEAD = 1,
|
|
Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD = 2,
|
|
Z_EROFS_VLE_CLUSTER_TYPE_RESERVED = 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
|
|
|
|
struct z_erofs_vle_decompressed_index {
|
|
__le16 di_advise;
|
|
/* where to decompress in the head cluster */
|
|
__le16 di_clusterofs;
|
|
|
|
union {
|
|
/* for the head cluster */
|
|
__le32 blkaddr;
|
|
/*
|
|
* for the rest clusters
|
|
* eg. for 4k page-sized cluster, maximum 4K*64k = 256M)
|
|
* [0] - pointing to the head cluster
|
|
* [1] - pointing to the tail cluster
|
|
*/
|
|
__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;
|
|
|
|
/* file types used in inode_info->flags */
|
|
enum {
|
|
EROFS_FT_UNKNOWN,
|
|
EROFS_FT_REG_FILE,
|
|
EROFS_FT_DIR,
|
|
EROFS_FT_CHRDEV,
|
|
EROFS_FT_BLKDEV,
|
|
EROFS_FT_FIFO,
|
|
EROFS_FT_SOCK,
|
|
EROFS_FT_SYMLINK,
|
|
EROFS_FT_MAX
|
|
};
|
|
|
|
#define EROFS_NAME_LEN 255
|
|
|
|
/* check the EROFS on-disk layout strictly at compile time */
|
|
static inline void erofs_check_ondisk_layout_definitions(void)
|
|
{
|
|
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 z_erofs_map_header) != 8);
|
|
BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8);
|
|
BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
|
|
|
|
BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
|
|
Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
|
|
}
|
|
|
|
#endif
|
|
|