| /* SPDX-License-Identifier: GPL-2.0 OR Apache-2.0 |
| * |
| * linux/drivers/staging/erofs/erofs_fs.h |
| * |
| * Copyright (C) 2017-2018 HUAWEI, Inc. |
| * http://www.huawei.com/ |
| * Created by Gao Xiang <gaoxiang25@huawei.com> |
| * |
| * This file is dual-licensed; you may select either the GNU General Public |
| * License version 2 or Apache License, Version 2.0. See the file COPYING |
| * in the main directory of the Linux distribution for more details. |
| */ |
| #ifndef __EROFS_FS_H |
| #define __EROFS_FS_H |
| |
| /* Enhanced(Extended) ROM File System */ |
| #define EROFS_SUPER_MAGIC_V1 0xE0F5E1E2 |
| #define EROFS_SUPER_OFFSET 1024 |
| |
| struct erofs_super_block { |
| /* 0 */__le32 magic; /* in the little endian */ |
| /* 4 */__le32 checksum; /* crc32c(super_block) */ |
| /* 8 */__le32 features; |
| /* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */ |
| /* 13 */__u8 reserved; |
| |
| /* 14 */__le16 root_nid; |
| /* 16 */__le64 inos; /* total valid ino # (== f_files - f_favail) */ |
| |
| /* 24 */__le64 build_time; /* inode v1 time derivation */ |
| /* 32 */__le32 build_time_nsec; |
| /* 36 */__le32 blocks; /* used for statfs */ |
| /* 40 */__le32 meta_blkaddr; |
| /* 44 */__le32 xattr_blkaddr; |
| /* 48 */__u8 uuid[16]; /* 128-bit uuid for volume */ |
| /* 64 */__u8 volume_name[16]; /* volume name */ |
| |
| /* 80 */__u8 reserved2[48]; /* 128 bytes */ |
| } __packed; |
| |
| /* |
| * erofs inode data mapping: |
| * 0 - inode plain without inline data A: |
| * inode, [xattrs], ... | ... | no-holed data |
| * 1 - inode VLE compression B: |
| * inode, [xattrs], extents ... | ... |
| * 2 - inode plain with inline data C: |
| * inode, [xattrs], last_inline_data, ... | ... | no-holed data |
| * 3~7 - reserved |
| */ |
| enum { |
| EROFS_INODE_LAYOUT_PLAIN, |
| EROFS_INODE_LAYOUT_COMPRESSION, |
| EROFS_INODE_LAYOUT_INLINE, |
| EROFS_INODE_LAYOUT_MAX |
| }; |
| |
| /* bit definitions of inode i_advise */ |
| #define EROFS_I_VERSION_BITS 1 |
| #define EROFS_I_DATA_MAPPING_BITS 3 |
| |
| #define EROFS_I_VERSION_BIT 0 |
| #define EROFS_I_DATA_MAPPING_BIT 1 |
| |
| struct erofs_inode_v1 { |
| /* 0 */__le16 i_advise; |
| |
| /* 1 header + n-1 * 4 bytes inline xattr to keep continuity */ |
| /* 2 */__le16 i_xattr_icount; |
| /* 4 */__le16 i_mode; |
| /* 6 */__le16 i_nlink; |
| /* 8 */__le32 i_size; |
| /* 12 */__le32 i_reserved; |
| /* 16 */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 __packed; |
| /* 20 */__le32 i_ino; /* only used for 32-bit stat compatibility */ |
| /* 24 */__le16 i_uid; |
| /* 26 */__le16 i_gid; |
| /* 28 */__le32 i_checksum; |
| } __packed; |
| |
| /* 32 bytes on-disk inode */ |
| #define EROFS_INODE_LAYOUT_V1 0 |
| /* 64 bytes on-disk inode */ |
| #define EROFS_INODE_LAYOUT_V2 1 |
| |
| struct erofs_inode_v2 { |
| __le16 i_advise; |
| |
| /* 1 header + n-1 * 4 bytes inline xattr to keep continuity */ |
| __le16 i_xattr_icount; |
| __le16 i_mode; |
| __le16 i_reserved; /* 8 bytes */ |
| __le64 i_size; /* 16 bytes */ |
| 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 __packed; |
| |
| /* only used for 32-bit stat compatibility */ |
| __le32 i_ino; /* 24 bytes */ |
| |
| __le32 i_uid; |
| __le32 i_gid; |
| __le64 i_ctime; /* 32 bytes */ |
| __le32 i_ctime_nsec; |
| __le32 i_nlink; |
| __u8 i_reserved2[12]; |
| __le32 i_checksum; /* 64 bytes */ |
| } __packed; |
| |
| #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_checksum; |
| __u8 h_shared_count; |
| __u8 h_reserved[7]; |
| __le32 h_shared_xattrs[0]; /* shared xattr id array */ |
| } __packed; |
| |
| /* 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 */ |
| } __packed; |
| |
| #define ondisk_xattr_ibody_size(count) ({\ |
| u32 __count = le16_to_cpu(count); \ |
| ((__count) == 0) ? 0 : \ |
| sizeof(struct erofs_xattr_ibody_header) + \ |
| sizeof(__u32) * ((__count) - 1); }) |
| |
| #define EROFS_XATTR_ALIGN(size) round_up(size, sizeof(struct erofs_xattr_entry)) |
| #define EROFS_XATTR_ENTRY_SIZE(entry) EROFS_XATTR_ALIGN( \ |
| sizeof(struct erofs_xattr_entry) + \ |
| (entry)->e_name_len + le16_to_cpu((entry)->e_value_size)) |
| |
| /* have to be aligned with 8 bytes on disk */ |
| struct erofs_extent_header { |
| __le32 eh_checksum; |
| __le32 eh_reserved[3]; |
| } __packed; |
| |
| /* |
| * Z_EROFS Variable-sized 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, |
| Z_EROFS_VLE_CLUSTER_TYPE_HEAD, |
| Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD, |
| Z_EROFS_VLE_CLUSTER_TYPE_RESERVED, |
| 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 __packed; /* 8 bytes */ |
| } __packed; |
| |
| #define Z_EROFS_VLE_EXTENT_ALIGN(size) round_up(size, \ |
| sizeof(struct z_erofs_vle_decompressed_index)) |
| |
| /* dirent sorts in alphabet order, thus we can do binary search */ |
| struct erofs_dirent { |
| __le64 nid; /* 0, node number */ |
| __le16 nameoff; /* 8, start offset of file name */ |
| __u8 file_type; /* 10, file type */ |
| __u8 reserved; /* 11, 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_v1) != 32); |
| BUILD_BUG_ON(sizeof(struct erofs_inode_v2) != 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_extent_header) != 16); |
| 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 |
| |