1 #ifndef _LINUX_MSDOS_FS_H 2 #define _LINUX_MSDOS_FS_H 3 4 #include <linux/magic.h> 5 #include <asm/byteorder.h> 6 7 /* 8 * The MS-DOS filesystem constants/structures 9 */ 10 11 #define SECTOR_SIZE 512 /* sector size (bytes) */ 12 #define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */ 13 #define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */ 14 #define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */ 15 #define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry)) 16 #define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */ 17 #define CF_LE_W(v) le16_to_cpu(v) 18 #define CF_LE_L(v) le32_to_cpu(v) 19 #define CT_LE_W(v) cpu_to_le16(v) 20 #define CT_LE_L(v) cpu_to_le32(v) 21 22 23 #define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */ 24 #define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */ 25 26 /* directory limit */ 27 #define FAT_MAX_DIR_ENTRIES (65536) 28 #define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS) 29 30 #define ATTR_NONE 0 /* no attribute bits */ 31 #define ATTR_RO 1 /* read-only */ 32 #define ATTR_HIDDEN 2 /* hidden */ 33 #define ATTR_SYS 4 /* system */ 34 #define ATTR_VOLUME 8 /* volume label */ 35 #define ATTR_DIR 16 /* directory */ 36 #define ATTR_ARCH 32 /* archived */ 37 38 /* attribute bits that are copied "as is" */ 39 #define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN) 40 /* bits that are used by the Windows 95/Windows NT extended FAT */ 41 #define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME) 42 43 #define CASE_LOWER_BASE 8 /* base is lower case */ 44 #define CASE_LOWER_EXT 16 /* extension is lower case */ 45 46 #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */ 47 #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG) 48 49 #define MSDOS_NAME 11 /* maximum name length */ 50 #define MSDOS_LONGNAME 256 /* maximum name length */ 51 #define MSDOS_SLOTS 21 /* max # of slots for short and long names */ 52 #define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */ 53 #define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */ 54 55 #define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \ 56 MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x)) 57 58 /* start of data cluster's entry (number of reserved clusters) */ 59 #define FAT_START_ENT 2 60 61 /* maximum number of clusters */ 62 #define MAX_FAT12 0xFF4 63 #define MAX_FAT16 0xFFF4 64 #define MAX_FAT32 0x0FFFFFF6 65 #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \ 66 MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12) 67 68 /* bad cluster mark */ 69 #define BAD_FAT12 0xFF7 70 #define BAD_FAT16 0xFFF7 71 #define BAD_FAT32 0x0FFFFFF7 72 73 /* standard EOF */ 74 #define EOF_FAT12 0xFFF 75 #define EOF_FAT16 0xFFFF 76 #define EOF_FAT32 0x0FFFFFFF 77 78 #define FAT_ENT_FREE (0) 79 #define FAT_ENT_BAD (BAD_FAT32) 80 #define FAT_ENT_EOF (EOF_FAT32) 81 82 #define FAT_FSINFO_SIG1 0x41615252 83 #define FAT_FSINFO_SIG2 0x61417272 84 #define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \ 85 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2) 86 87 struct __fat_dirent { 88 long d_ino; 89 __kernel_off_t d_off; 90 unsigned short d_reclen; 91 char d_name[256]; /* We must not include limits.h! */ 92 }; 93 94 /* 95 * ioctl commands 96 */ 97 #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct __fat_dirent[2]) 98 #define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct __fat_dirent[2]) 99 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */ 100 #define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32) 101 #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32) 102 103 struct fat_boot_sector { 104 __u8 ignored[3]; /* Boot strap short or near jump */ 105 __u8 system_id[8]; /* Name - can be used to special case 106 partition manager volumes */ 107 __u8 sector_size[2]; /* bytes per logical sector */ 108 __u8 sec_per_clus; /* sectors/cluster */ 109 __le16 reserved; /* reserved sectors */ 110 __u8 fats; /* number of FATs */ 111 __u8 dir_entries[2]; /* root directory entries */ 112 __u8 sectors[2]; /* number of sectors */ 113 __u8 media; /* media code */ 114 __le16 fat_length; /* sectors/FAT */ 115 __le16 secs_track; /* sectors per track */ 116 __le16 heads; /* number of heads */ 117 __le32 hidden; /* hidden sectors (unused) */ 118 __le32 total_sect; /* number of sectors (if sectors == 0) */ 119 120 /* The following fields are only used by FAT32 */ 121 __le32 fat32_length; /* sectors/FAT */ 122 __le16 flags; /* bit 8: fat mirroring, low 4: active fat */ 123 __u8 version[2]; /* major, minor filesystem version */ 124 __le32 root_cluster; /* first cluster in root directory */ 125 __le16 info_sector; /* filesystem info sector */ 126 __le16 backup_boot; /* backup boot sector */ 127 __le16 reserved2[6]; /* Unused */ 128 }; 129 130 struct fat_boot_fsinfo { 131 __le32 signature1; /* 0x41615252L */ 132 __le32 reserved1[120]; /* Nothing as far as I can tell */ 133 __le32 signature2; /* 0x61417272L */ 134 __le32 free_clusters; /* Free cluster count. -1 if unknown */ 135 __le32 next_cluster; /* Most recently allocated cluster */ 136 __le32 reserved2[4]; 137 }; 138 139 struct msdos_dir_entry { 140 __u8 name[MSDOS_NAME];/* name and extension */ 141 __u8 attr; /* attribute bits */ 142 __u8 lcase; /* Case for base and extension */ 143 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */ 144 __le16 ctime; /* Creation time */ 145 __le16 cdate; /* Creation date */ 146 __le16 adate; /* Last access date */ 147 __le16 starthi; /* High 16 bits of cluster in FAT32 */ 148 __le16 time,date,start;/* time, date and first cluster */ 149 __le32 size; /* file size (in bytes) */ 150 }; 151 152 /* Up to 13 characters of the name */ 153 struct msdos_dir_slot { 154 __u8 id; /* sequence number for slot */ 155 __u8 name0_4[10]; /* first 5 characters in name */ 156 __u8 attr; /* attribute byte */ 157 __u8 reserved; /* always 0 */ 158 __u8 alias_checksum; /* checksum for 8.3 alias */ 159 __u8 name5_10[12]; /* 6 more characters in name */ 160 __le16 start; /* starting cluster number, 0 in long slots */ 161 __u8 name11_12[4]; /* last 2 characters in name */ 162 }; 163 164 #ifdef __KERNEL__ 165 /* media of boot sector */ 166 static inline int fat_valid_media(u8 media) 167 { 168 return 0xf8 <= media || media == 0xf0; 169 } 170 #endif /* !__KERNEL__ */ 171 #endif /* !_LINUX_MSDOS_FS_H */ 172