msdos_fs.h (6730B) - Raw
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _LINUX_MSDOS_FS_H 3 #define _LINUX_MSDOS_FS_H 4 5 #include <linux/types.h> 6 #include <linux/magic.h> 7 #include <asm/byteorder.h> 8 9 /* 10 * The MS-DOS filesystem constants/structures 11 */ 12 13 #ifndef SECTOR_SIZE 14 #define SECTOR_SIZE 512 /* sector size (bytes) */ 15 #endif 16 #define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */ 17 #define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */ 18 #define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */ 19 #define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry)) 20 #define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */ 21 #define MSDOS_LONGNAME 256 /* maximum name length */ 22 #define CF_LE_W(v) le16_to_cpu(v) 23 #define CF_LE_L(v) le32_to_cpu(v) 24 #define CT_LE_W(v) cpu_to_le16(v) 25 #define CT_LE_L(v) cpu_to_le32(v) 26 27 #define MSDOS_ROOT_INO 1 /* The root inode number */ 28 #define MSDOS_FSINFO_INO 2 /* Used for managing the FSINFO block */ 29 30 #define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */ 31 32 /* directory limit */ 33 #define FAT_MAX_DIR_ENTRIES (65536) 34 #define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS) 35 36 #define ATTR_NONE 0 /* no attribute bits */ 37 #define ATTR_RO 1 /* read-only */ 38 #define ATTR_HIDDEN 2 /* hidden */ 39 #define ATTR_SYS 4 /* system */ 40 #define ATTR_VOLUME 8 /* volume label */ 41 #define ATTR_DIR 16 /* directory */ 42 #define ATTR_ARCH 32 /* archived */ 43 44 /* attribute bits that are copied "as is" */ 45 #define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN) 46 /* bits that are used by the Windows 95/Windows NT extended FAT */ 47 #define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME) 48 49 #define CASE_LOWER_BASE 8 /* base is lower case */ 50 #define CASE_LOWER_EXT 16 /* extension is lower case */ 51 52 #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */ 53 #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG) 54 55 #define FAT_LFN_LEN 255 /* maximum long name length */ 56 #define MSDOS_NAME 11 /* maximum name length */ 57 #define MSDOS_SLOTS 21 /* max # of slots for short and long names */ 58 #define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */ 59 #define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */ 60 61 /* start of data cluster's entry (number of reserved clusters) */ 62 #define FAT_START_ENT 2 63 64 /* maximum number of clusters */ 65 #define MAX_FAT12 0xFF4 66 #define MAX_FAT16 0xFFF4 67 #define MAX_FAT32 0x0FFFFFF6 68 69 /* bad cluster mark */ 70 #define BAD_FAT12 0xFF7 71 #define BAD_FAT16 0xFFF7 72 #define BAD_FAT32 0x0FFFFFF7 73 74 /* standard EOF */ 75 #define EOF_FAT12 0xFFF 76 #define EOF_FAT16 0xFFFF 77 #define EOF_FAT32 0x0FFFFFFF 78 79 #define FAT_ENT_FREE (0) 80 #define FAT_ENT_BAD (BAD_FAT32) 81 #define FAT_ENT_EOF (EOF_FAT32) 82 83 #define FAT_FSINFO_SIG1 0x41615252 84 #define FAT_FSINFO_SIG2 0x61417272 85 #define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \ 86 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2) 87 88 #define FAT_STATE_DIRTY 0x01 89 90 struct __fat_dirent { 91 long d_ino; 92 __kernel_off_t d_off; 93 unsigned short d_reclen; 94 char d_name[256]; /* We must not include limits.h! */ 95 }; 96 97 /* 98 * ioctl commands 99 */ 100 #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct __fat_dirent[2]) 101 #define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct __fat_dirent[2]) 102 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */ 103 #define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32) 104 #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32) 105 /*Android kernel has used 0x12, so we use 0x13*/ 106 #define FAT_IOCTL_GET_VOLUME_ID _IOR('r', 0x13, __u32) 107 108 struct fat_boot_sector { 109 __u8 ignored[3]; /* Boot strap short or near jump */ 110 __u8 system_id[8]; /* Name - can be used to special case 111 partition manager volumes */ 112 __u8 sector_size[2]; /* bytes per logical sector */ 113 __u8 sec_per_clus; /* sectors/cluster */ 114 __le16 reserved; /* reserved sectors */ 115 __u8 fats; /* number of FATs */ 116 __u8 dir_entries[2]; /* root directory entries */ 117 __u8 sectors[2]; /* number of sectors */ 118 __u8 media; /* media code */ 119 __le16 fat_length; /* sectors/FAT */ 120 __le16 secs_track; /* sectors per track */ 121 __le16 heads; /* number of heads */ 122 __le32 hidden; /* hidden sectors (unused) */ 123 __le32 total_sect; /* number of sectors (if sectors == 0) */ 124 125 union { 126 struct { 127 /* Extended BPB Fields for FAT16 */ 128 __u8 drive_number; /* Physical drive number */ 129 __u8 state; /* undocumented, but used 130 for mount state. */ 131 __u8 signature; /* extended boot signature */ 132 __u8 vol_id[4]; /* volume ID */ 133 __u8 vol_label[MSDOS_NAME]; /* volume label */ 134 __u8 fs_type[8]; /* file system type */ 135 /* other fields are not added here */ 136 } fat16; 137 138 struct { 139 /* only used by FAT32 */ 140 __le32 length; /* sectors/FAT */ 141 __le16 flags; /* bit 8: fat mirroring, 142 low 4: active fat */ 143 __u8 version[2]; /* major, minor filesystem 144 version */ 145 __le32 root_cluster; /* first cluster in 146 root directory */ 147 __le16 info_sector; /* filesystem info sector */ 148 __le16 backup_boot; /* backup boot sector */ 149 __le16 reserved2[6]; /* Unused */ 150 /* Extended BPB Fields for FAT32 */ 151 __u8 drive_number; /* Physical drive number */ 152 __u8 state; /* undocumented, but used 153 for mount state. */ 154 __u8 signature; /* extended boot signature */ 155 __u8 vol_id[4]; /* volume ID */ 156 __u8 vol_label[MSDOS_NAME]; /* volume label */ 157 __u8 fs_type[8]; /* file system type */ 158 /* other fields are not added here */ 159 } fat32; 160 }; 161 }; 162 163 struct fat_boot_fsinfo { 164 __le32 signature1; /* 0x41615252L */ 165 __le32 reserved1[120]; /* Nothing as far as I can tell */ 166 __le32 signature2; /* 0x61417272L */ 167 __le32 free_clusters; /* Free cluster count. -1 if unknown */ 168 __le32 next_cluster; /* Most recently allocated cluster */ 169 __le32 reserved2[4]; 170 }; 171 172 struct msdos_dir_entry { 173 __u8 name[MSDOS_NAME];/* name and extension */ 174 __u8 attr; /* attribute bits */ 175 __u8 lcase; /* Case for base and extension */ 176 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */ 177 __le16 ctime; /* Creation time */ 178 __le16 cdate; /* Creation date */ 179 __le16 adate; /* Last access date */ 180 __le16 starthi; /* High 16 bits of cluster in FAT32 */ 181 __le16 time,date,start;/* time, date and first cluster */ 182 __le32 size; /* file size (in bytes) */ 183 }; 184 185 /* Up to 13 characters of the name */ 186 struct msdos_dir_slot { 187 __u8 id; /* sequence number for slot */ 188 __u8 name0_4[10]; /* first 5 characters in name */ 189 __u8 attr; /* attribute byte */ 190 __u8 reserved; /* always 0 */ 191 __u8 alias_checksum; /* checksum for 8.3 alias */ 192 __u8 name5_10[12]; /* 6 more characters in name */ 193 __le16 start; /* starting cluster number, 0 in long slots */ 194 __u8 name11_12[4]; /* last 2 characters in name */ 195 }; 196 197 #endif /* _LINUX_MSDOS_FS_H */