/src/u-boot/fs/erofs/erofs_fs.h

Source
/* 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

#include <asm/unaligned.h>
#include <fs.h>
#include <part.h>
#include <stdint.h>
#include <compiler.h>

#define EROFS_SUPER_MAGIC_V1    0xE0F5E1E2
#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_FEATURE_INCOMPAT_DEDUPE   0x00000020
#define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES 0x00000040
#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 | \
   EROFS_FEATURE_INCOMPAT_DEDUPE | \
   EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES)

#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;         /* filesystem block size in bit shift */
  __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 dirblkbits;  /* directory block size in bit shift */
  __u8 xattr_prefix_count;  /* # of long xattr name prefixes */
  __le32 xattr_prefix_start;  /* start of long xattr prefixes */
  __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:
 * 1 - compressed inode with non-compact indexes:
 * 2 - uncompressed flat inode with tail-packing inline data:
 * 3 - compressed inode with compact indexes:
 * 4 - chunk-based inode with (optional) multi-device support:
 * 5~7 - reserved
 */
enum {
  EROFS_INODE_FLAT_PLAIN      = 0,
  EROFS_INODE_COMPRESSED_FULL   = 1,
  EROFS_INODE_FLAT_INLINE     = 2,
  EROFS_INODE_COMPRESSED_COMPACT    = 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_COMPRESSED_COMPACT ||
    datamode == EROFS_INODE_COMPRESSED_FULL;
}

/* 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)

/* 32-byte on-disk inode */
#define EROFS_INODE_LAYOUT_COMPACT  0
/* 64-byte on-disk inode */
#define EROFS_INODE_LAYOUT_EXTENDED 1

struct erofs_inode_chunk_info {
  __le16 format;    /* chunk blkbits, etc. */
  __le16 reserved;
};

union erofs_inode_i_u {
  /* 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;
};

/* 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 erofs_inode_i_u i_u;

  __le32 i_ino;   /* only used for 32-bit stat compatibility */
  __le16 i_uid;
  __le16 i_gid;
  __le32 i_reserved2;
};

/* 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 erofs_inode_i_u i_u;

  __le32 i_ino;   /* only used for 32-bit stat compatibility */
  __le32 i_uid;
  __le32 i_gid;
  __le64 i_mtime;
  __le32 i_mtime_nsec;
  __le32 i_nlink;
  __u8   i_reserved2[16];
};

/*
 * 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

/*
 * bit 7 of e_name_index is set when it refers to a long xattr name prefix,
 * while the remained lower bits represent the index of the prefix.
 */
#define EROFS_XATTR_LONG_PREFIX   0x80
#define EROFS_XATTR_LONG_PREFIX_MASK  0x7f

/* 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 */
};

/* long xattr name prefix */
struct erofs_xattr_long_prefix {
  __u8   base_index;  /* short xattr name prefix index */
  char   infix[0];  /* infix apart from short prefix */
};

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 */
};

/* 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

/* 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_DEFLATE = 2,
  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;
};

/*
 * 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_LCLUSTER_TYPE_PLAIN = 0,
  Z_EROFS_LCLUSTER_TYPE_HEAD1 = 1,
  Z_EROFS_LCLUSTER_TYPE_NONHEAD = 2,
  Z_EROFS_LCLUSTER_TYPE_HEAD2 = 3,
  Z_EROFS_LCLUSTER_TYPE_MAX
};

#define Z_EROFS_LI_LCLUSTER_TYPE_BITS        2
#define Z_EROFS_LI_LCLUSTER_TYPE_BIT         0

/* (noncompact only, HEAD) This pcluster refers to partial decompressed data */
#define Z_EROFS_LI_PARTIAL_REF    (1 << 15)

/*
 * 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_LI_D0_CBLKCNT   (1 << 11)

struct z_erofs_lcluster_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_FULL_INDEX_ALIGN(end) \
  (round_up(end, 8) + sizeof(struct z_erofs_map_header) + 8)

/* check the EROFS on-disk layout strictly at compile time */
static inline void erofs_check_ondisk_layout_definitions(void)
{
  const __le64 fmh __maybe_unused =
    *(__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_lcluster_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_lcluster_index));
  BUILD_BUG_ON(sizeof(struct erofs_deviceslot) != 128);

  BUILD_BUG_ON(BIT(Z_EROFS_LI_LCLUSTER_TYPE_BITS) <
         Z_EROFS_LCLUSTER_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

Coverage Report

Created: 2026-03-11 06:21

Line	Count	Source
1		/* SPDX-License-Identifier: GPL-2.0-only OR Apache-2.0 */
2		/*
3		* EROFS (Enhanced ROM File System) on-disk format definition
4		*
5		* Copyright (C) 2017-2018 HUAWEI, Inc.
6		* https://www.huawei.com/
7		* Copyright (C) 2021, Alibaba Cloud
8		*/
9		#ifndef __EROFS_FS_H
10		#define __EROFS_FS_H
11
12		#include <asm/unaligned.h>
13		#include <fs.h>
14		#include <part.h>
15		#include <stdint.h>
16		#include <compiler.h>
17
18	0	#define EROFS_SUPER_MAGIC_V1 0xE0F5E1E2
19	0	#define EROFS_SUPER_OFFSET 1024
20
21		#define EROFS_FEATURE_COMPAT_SB_CHKSUM 0x00000001
22		#define EROFS_FEATURE_COMPAT_MTIME 0x00000002
23
24		/*
25		* Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
26		* be incompatible with this kernel version.
27		*/
28	0	#define EROFS_FEATURE_INCOMPAT_ZERO_PADDING 0x00000001
29	0	#define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002
30	0	#define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER 0x00000002
31	0	#define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE 0x00000004
32	0	#define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE 0x00000008
33	0	#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 0x00000008
34	0	#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING 0x00000010
35	0	#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
36	0	#define EROFS_FEATURE_INCOMPAT_DEDUPE 0x00000020
37	0	#define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES 0x00000040
38		#define EROFS_ALL_FEATURE_INCOMPAT \
39	0	(EROFS_FEATURE_INCOMPAT_ZERO_PADDING \| \
40	0	EROFS_FEATURE_INCOMPAT_COMPR_CFGS \| \
41	0	EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER \| \
42	0	EROFS_FEATURE_INCOMPAT_CHUNKED_FILE \| \
43	0	EROFS_FEATURE_INCOMPAT_DEVICE_TABLE \| \
44	0	EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 \| \
45	0	EROFS_FEATURE_INCOMPAT_ZTAILPACKING \| \
46	0	EROFS_FEATURE_INCOMPAT_FRAGMENTS \| \
47	0	EROFS_FEATURE_INCOMPAT_DEDUPE \| \
48	0	EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES)
49
50		#define EROFS_SB_EXTSLOT_SIZE 16
51
52		struct erofs_deviceslot {
53		u8 tag[64]; /* digest(sha256), etc. */
54		__le32 blocks; /* total fs blocks of this device */
55		__le32 mapped_blkaddr; /* map starting at mapped_blkaddr */
56		u8 reserved[56];
57		};
58
59	0	#define EROFS_DEVT_SLOT_SIZE sizeof(struct erofs_deviceslot)
60
61		/* erofs on-disk super block (currently 128 bytes) */
62		struct erofs_super_block {
63		__le32 magic; /* file system magic number */
64		__le32 checksum; /* crc32c(super_block) */
65		__le32 feature_compat;
66		__u8 blkszbits; /* filesystem block size in bit shift */
67		__u8 sb_extslots; /* superblock size = 128 + sb_extslots * 16 */
68
69		__le16 root_nid; /* nid of root directory */
70		__le64 inos; /* total valid ino # (== f_files - f_favail) */
71
72		__le64 build_time; /* compact inode time derivation */
73		__le32 build_time_nsec; /* compact inode time derivation in ns scale */
74		__le32 blocks; /* used for statfs */
75		__le32 meta_blkaddr; /* start block address of metadata area */
76		__le32 xattr_blkaddr; /* start block address of shared xattr area */
77		__u8 uuid[16]; /* 128-bit uuid for volume */
78		__u8 volume_name[16]; /* volume name */
79		__le32 feature_incompat;
80		union {
81		/* bitmap for available compression algorithms */
82		__le16 available_compr_algs;
83		/* customized sliding window size instead of 64k by default */
84		__le16 lz4_max_distance;
85		} __packed u1;
86		__le16 extra_devices; /* # of devices besides the primary device */
87		__le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */
88		__u8 dirblkbits; /* directory block size in bit shift */
89		__u8 xattr_prefix_count; /* # of long xattr name prefixes */
90		__le32 xattr_prefix_start; /* start of long xattr prefixes */
91		__le64 packed_nid; /* nid of the special packed inode */
92		__u8 reserved2[24];
93		};
94
95		/*
96		* EROFS inode datalayout (i_format in on-disk inode):
97		* 0 - uncompressed flat inode without tail-packing inline data:
98		* 1 - compressed inode with non-compact indexes:
99		* 2 - uncompressed flat inode with tail-packing inline data:
100		* 3 - compressed inode with compact indexes:
101		* 4 - chunk-based inode with (optional) multi-device support:
102		* 5~7 - reserved
103		*/
104		enum {
105		EROFS_INODE_FLAT_PLAIN = 0,
106		EROFS_INODE_COMPRESSED_FULL = 1,
107		EROFS_INODE_FLAT_INLINE = 2,
108		EROFS_INODE_COMPRESSED_COMPACT = 3,
109		EROFS_INODE_CHUNK_BASED = 4,
110		EROFS_INODE_DATALAYOUT_MAX
111		};
112
113		static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
114	0	{
115	0	return datamode == EROFS_INODE_COMPRESSED_COMPACT \|\|
116	0	datamode == EROFS_INODE_COMPRESSED_FULL;
117	0	} Unexecuted instantiation: fs.c:erofs_inode_is_data_compressed Unexecuted instantiation: super.c:erofs_inode_is_data_compressed Unexecuted instantiation: namei.c:erofs_inode_is_data_compressed Unexecuted instantiation: data.c:erofs_inode_is_data_compressed Unexecuted instantiation: decompress.c:erofs_inode_is_data_compressed Unexecuted instantiation: zmap.c:erofs_inode_is_data_compressed
118
119		/* bit definitions of inode i_format */
120	0	#define EROFS_I_VERSION_BITS 1
121	0	#define EROFS_I_DATALAYOUT_BITS 3
122
123	0	#define EROFS_I_VERSION_BIT 0
124	0	#define EROFS_I_DATALAYOUT_BIT 1
125
126		#define EROFS_I_ALL \
127		((1 << (EROFS_I_DATALAYOUT_BIT + EROFS_I_DATALAYOUT_BITS)) - 1)
128
129		/* indicate chunk blkbits, thus 'chunksize = blocksize << chunk blkbits' */
130	0	#define EROFS_CHUNK_FORMAT_BLKBITS_MASK 0x001F
131		/* with chunk indexes or just a 4-byte blkaddr array */
132	0	#define EROFS_CHUNK_FORMAT_INDEXES 0x0020
133
134		#define EROFS_CHUNK_FORMAT_ALL \
135	0	(EROFS_CHUNK_FORMAT_BLKBITS_MASK \| EROFS_CHUNK_FORMAT_INDEXES)
136
137		/* 32-byte on-disk inode */
138	0	#define EROFS_INODE_LAYOUT_COMPACT 0
139		/* 64-byte on-disk inode */
140	0	#define EROFS_INODE_LAYOUT_EXTENDED 1
141
142		struct erofs_inode_chunk_info {
143		__le16 format; /* chunk blkbits, etc. */
144		__le16 reserved;
145		};
146
147		union erofs_inode_i_u {
148		/* total compressed blocks for compressed inodes */
149		__le32 compressed_blocks;
150
151		/* block address for uncompressed flat inodes */
152		__le32 raw_blkaddr;
153
154		/* for device files, used to indicate old/new device # */
155		__le32 rdev;
156
157		/* for chunk-based files, it contains the summary info */
158		struct erofs_inode_chunk_info c;
159		};
160
161		/* 32-byte reduced form of an ondisk inode */
162		struct erofs_inode_compact {
163		__le16 i_format; /* inode format hints */
164
165		/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
166		__le16 i_xattr_icount;
167		__le16 i_mode;
168		__le16 i_nlink;
169		__le32 i_size;
170		__le32 i_reserved;
171		union erofs_inode_i_u i_u;
172
173		__le32 i_ino; /* only used for 32-bit stat compatibility */
174		__le16 i_uid;
175		__le16 i_gid;
176		__le32 i_reserved2;
177		};
178
179		/* 64-byte complete form of an ondisk inode */
180		struct erofs_inode_extended {
181		__le16 i_format; /* inode format hints */
182
183		/* 1 header + n-1 * 4 bytes inline xattr to keep continuity */
184		__le16 i_xattr_icount;
185		__le16 i_mode;
186		__le16 i_reserved;
187		__le64 i_size;
188		union erofs_inode_i_u i_u;
189
190		__le32 i_ino; /* only used for 32-bit stat compatibility */
191		__le32 i_uid;
192		__le32 i_gid;
193		__le64 i_mtime;
194		__le32 i_mtime_nsec;
195		__le32 i_nlink;
196		__u8 i_reserved2[16];
197		};
198
199		/*
200		* inline xattrs (n == i_xattr_icount):
201		* erofs_xattr_ibody_header(1) + (n - 1) * 4 bytes
202		* 12 bytes / \
203		* / \
204		* /-----------------------\
205		* \| erofs_xattr_entries+ \|
206		* +-----------------------+
207		* inline xattrs must starts in erofs_xattr_ibody_header,
208		* for read-only fs, no need to introduce h_refcount
209		*/
210		struct erofs_xattr_ibody_header {
211		__le32 h_reserved;
212		__u8 h_shared_count;
213		__u8 h_reserved2[7];
214		__le32 h_shared_xattrs[0]; /* shared xattr id array */
215		};
216
217		/* Name indexes */
218		#define EROFS_XATTR_INDEX_USER 1
219		#define EROFS_XATTR_INDEX_POSIX_ACL_ACCESS 2
220		#define EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
221		#define EROFS_XATTR_INDEX_TRUSTED 4
222		#define EROFS_XATTR_INDEX_LUSTRE 5
223		#define EROFS_XATTR_INDEX_SECURITY 6
224
225		/*
226		* bit 7 of e_name_index is set when it refers to a long xattr name prefix,
227		* while the remained lower bits represent the index of the prefix.
228		*/
229		#define EROFS_XATTR_LONG_PREFIX 0x80
230		#define EROFS_XATTR_LONG_PREFIX_MASK 0x7f
231
232		/* xattr entry (for both inline & shared xattrs) */
233		struct erofs_xattr_entry {
234		__u8 e_name_len; /* length of name */
235		__u8 e_name_index; /* attribute name index */
236		__le16 e_value_size; /* size of attribute value */
237		/* followed by e_name and e_value */
238		char e_name[0]; /* attribute name */
239		};
240
241		/* long xattr name prefix */
242		struct erofs_xattr_long_prefix {
243		__u8 base_index; /* short xattr name prefix index */
244		char infix[0]; /* infix apart from short prefix */
245		};
246
247		static inline unsigned int erofs_xattr_ibody_size(__le16 i_xattr_icount)
248	0	{
249	0	if (!i_xattr_icount)
250	0	return 0;
251
252	0	return sizeof(struct erofs_xattr_ibody_header) +
253	0	sizeof(__u32) * (le16_to_cpu(i_xattr_icount) - 1);
254	0	} Unexecuted instantiation: fs.c:erofs_xattr_ibody_size Unexecuted instantiation: super.c:erofs_xattr_ibody_size Unexecuted instantiation: namei.c:erofs_xattr_ibody_size Unexecuted instantiation: data.c:erofs_xattr_ibody_size Unexecuted instantiation: decompress.c:erofs_xattr_ibody_size Unexecuted instantiation: zmap.c:erofs_xattr_ibody_size
255
256		#define EROFS_XATTR_ALIGN(size) round_up(size, sizeof(struct erofs_xattr_entry))
257
258		static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e)
259	0	{
260	0	return EROFS_XATTR_ALIGN(sizeof(struct erofs_xattr_entry) +
261	0	e->e_name_len + le16_to_cpu(e->e_value_size));
262	0	} Unexecuted instantiation: fs.c:erofs_xattr_entry_size Unexecuted instantiation: super.c:erofs_xattr_entry_size Unexecuted instantiation: namei.c:erofs_xattr_entry_size Unexecuted instantiation: data.c:erofs_xattr_entry_size Unexecuted instantiation: decompress.c:erofs_xattr_entry_size Unexecuted instantiation: zmap.c:erofs_xattr_entry_size
263
264		/* represent a zeroed chunk (hole) */
265	0	#define EROFS_NULL_ADDR -1
266
267		/* 4-byte block address array */
268	0	#define EROFS_BLOCK_MAP_ENTRY_SIZE sizeof(__le32)
269
270		/* 8-byte inode chunk indexes */
271		struct erofs_inode_chunk_index {
272		__le16 advise; /* always 0, don't care for now */
273		__le16 device_id; /* back-end storage id (with bits masked) */
274		__le32 blkaddr; /* start block address of this inode chunk */
275		};
276
277		/* dirent sorts in alphabet order, thus we can do binary search */
278		struct erofs_dirent {
279		__le64 nid; /* node number */
280		__le16 nameoff; /* start offset of file name */
281		__u8 file_type; /* file type */
282		__u8 reserved; /* reserved */
283		} __packed;
284
285		/* file types used in inode_info->flags */
286		enum {
287		EROFS_FT_UNKNOWN,
288		EROFS_FT_REG_FILE,
289		EROFS_FT_DIR,
290		EROFS_FT_CHRDEV,
291		EROFS_FT_BLKDEV,
292		EROFS_FT_FIFO,
293		EROFS_FT_SOCK,
294		EROFS_FT_SYMLINK,
295		EROFS_FT_MAX
296		};
297
298	0	#define EROFS_NAME_LEN 255
299
300		/* maximum supported size of a physical compression cluster */
301		#define Z_EROFS_PCLUSTER_MAX_SIZE (1024 * 1024)
302
303		/* available compression algorithm types (for h_algorithmtype) */
304		enum {
305		Z_EROFS_COMPRESSION_LZ4 = 0,
306		Z_EROFS_COMPRESSION_LZMA = 1,
307		Z_EROFS_COMPRESSION_DEFLATE = 2,
308		Z_EROFS_COMPRESSION_MAX
309		};
310
311		#define Z_EROFS_ALL_COMPR_ALGS ((1 << Z_EROFS_COMPRESSION_MAX) - 1)
312
313		/* 14 bytes (+ length field = 16 bytes) */
314		struct z_erofs_lz4_cfgs {
315		__le16 max_distance;
316		__le16 max_pclusterblks;
317		u8 reserved[10];
318		} __packed;
319
320		/* 14 bytes (+ length field = 16 bytes) */
321		struct z_erofs_lzma_cfgs {
322		__le32 dict_size;
323		__le16 format;
324		u8 reserved[8];
325		} __packed;
326
327		#define Z_EROFS_LZMA_MAX_DICT_SIZE (8 * Z_EROFS_PCLUSTER_MAX_SIZE)
328
329		/*
330		* bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
331		* e.g. for 4k logical cluster size, 4B if compacted 2B is off;
332		* (4B) + 2B + (4B) if compacted 2B is on.
333		* bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
334		* bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
335		* bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
336		* bit 4 : interlaced plain pcluster (0 - off; 1 - on)
337		* bit 5 : fragment pcluster (0 - off; 1 - on)
338		*/
339	0	#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
340	0	#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
341	0	#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
342	0	#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
343	0	#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010
344	0	#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER 0x0020
345
346	0	#define Z_EROFS_FRAGMENT_INODE_BIT 7
347		struct z_erofs_map_header {
348		union {
349		/* fragment data offset in the packed inode */
350		__le32 h_fragmentoff;
351		struct {
352		__le16 h_reserved1;
353		/* indicates the encoded size of tailpacking data */
354		__le16 h_idata_size;
355		};
356		};
357		__le16 h_advise;
358		/*
359		* bit 0-3 : algorithm type of head 1 (logical cluster type 01);
360		* bit 4-7 : algorithm type of head 2 (logical cluster type 11).
361		*/
362		__u8 h_algorithmtype;
363		/*
364		* bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
365		* bit 3-6 : reserved;
366		* bit 7 : move the whole file into packed inode or not.
367		*/
368		__u8 h_clusterbits;
369		};
370
371		/*
372		* On-disk logical cluster type:
373		* 0 - literal (uncompressed) lcluster
374		* 1,3 - compressed lcluster (for HEAD lclusters)
375		* 2 - compressed lcluster (for NONHEAD lclusters)
376		*
377		* In detail,
378		* 0 - literal (uncompressed) lcluster,
379		* di_advise = 0
380		* di_clusterofs = the literal data offset of the lcluster
381		* di_blkaddr = the blkaddr of the literal pcluster
382		*
383		* 1,3 - compressed lcluster (for HEAD lclusters)
384		* di_advise = 1 or 3
385		* di_clusterofs = the decompressed data offset of the lcluster
386		* di_blkaddr = the blkaddr of the compressed pcluster
387		*
388		* 2 - compressed lcluster (for NONHEAD lclusters)
389		* di_advise = 2
390		* di_clusterofs =
391		* the decompressed data offset in its own HEAD lcluster
392		* di_u.delta[0] = distance to this HEAD lcluster
393		* di_u.delta[1] = distance to the next HEAD lcluster
394		*/
395		enum {
396		Z_EROFS_LCLUSTER_TYPE_PLAIN = 0,
397		Z_EROFS_LCLUSTER_TYPE_HEAD1 = 1,
398		Z_EROFS_LCLUSTER_TYPE_NONHEAD = 2,
399		Z_EROFS_LCLUSTER_TYPE_HEAD2 = 3,
400		Z_EROFS_LCLUSTER_TYPE_MAX
401		};
402
403	0	#define Z_EROFS_LI_LCLUSTER_TYPE_BITS 2
404	0	#define Z_EROFS_LI_LCLUSTER_TYPE_BIT 0
405
406		/* (noncompact only, HEAD) This pcluster refers to partial decompressed data */
407	0	#define Z_EROFS_LI_PARTIAL_REF (1 << 15)
408
409		/*
410		* D0_CBLKCNT will be marked _only_ at the 1st non-head lcluster to store the
411		* compressed block count of a compressed extent (in logical clusters, aka.
412		* block count of a pcluster).
413		*/
414	0	#define Z_EROFS_LI_D0_CBLKCNT (1 << 11)
415
416		struct z_erofs_lcluster_index {
417		__le16 di_advise;
418		/* where to decompress in the head lcluster */
419		__le16 di_clusterofs;
420
421		union {
422		/* for the HEAD lclusters */
423		__le32 blkaddr;
424		/*
425		* for the NONHEAD lclusters
426		* [0] - distance to its HEAD lcluster
427		* [1] - distance to the next HEAD lcluster
428		*/
429		__le16 delta[2];
430		} di_u;
431		};
432
433		#define Z_EROFS_FULL_INDEX_ALIGN(end) \
434	0	(round_up(end, 8) + sizeof(struct z_erofs_map_header) + 8)
435
436		/* check the EROFS on-disk layout strictly at compile time */
437		static inline void erofs_check_ondisk_layout_definitions(void)
438	0	{
439	0	const __le64 fmh __maybe_unused =
440	0	(__le64 )&(struct z_erofs_map_header) {
441	0	.h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
442	0	};
443	0
444	0	BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
445	0	BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
446	0	BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
447	0	BUILD_BUG_ON(sizeof(struct erofs_xattr_ibody_header) != 12);
448	0	BUILD_BUG_ON(sizeof(struct erofs_xattr_entry) != 4);
449	0	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_info) != 4);
450	0	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) != 8);
451	0	BUILD_BUG_ON(sizeof(struct z_erofs_map_header) != 8);
452	0	BUILD_BUG_ON(sizeof(struct z_erofs_lcluster_index) != 8);
453	0	BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
454	0	/* keep in sync between 2 index structures for better extendibility */
455	0	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) !=
456	0	sizeof(struct z_erofs_lcluster_index));
457	0	BUILD_BUG_ON(sizeof(struct erofs_deviceslot) != 128);
458	0
459	0	BUILD_BUG_ON(BIT(Z_EROFS_LI_LCLUSTER_TYPE_BITS) <
460	0	Z_EROFS_LCLUSTER_TYPE_MAX - 1);
461	0	/* exclude old compiler versions like gcc 7.5.0 */
462	0	BUILD_BUG_ON(__builtin_constant_p(fmh) ?
463	0	fmh != cpu_to_le64(1ULL << 63) : 0);
464	0	} Unexecuted instantiation: fs.c:erofs_check_ondisk_layout_definitions Unexecuted instantiation: super.c:erofs_check_ondisk_layout_definitions Unexecuted instantiation: namei.c:erofs_check_ondisk_layout_definitions Unexecuted instantiation: data.c:erofs_check_ondisk_layout_definitions Unexecuted instantiation: decompress.c:erofs_check_ondisk_layout_definitions Unexecuted instantiation: zmap.c:erofs_check_ondisk_layout_definitions
465
466		#endif