1#ifndef _LINUX_MSDOS_FS_H 2#define _LINUX_MSDOS_FS_H 3 4#include <linux/types.h> 5#include <linux/magic.h> 6#include <asm/byteorder.h> 7 8/* 9 * The MS-DOS filesystem constants/structures 10 */ 11 12#define SECTOR_SIZE 512 /* sector size (bytes) */ 13#define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */ 14#define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */ 15#define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */ 16#define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry)) 17#define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */ 18#define MSDOS_LONGNAME 256 /* maximum name length */ 19#define CF_LE_W(v) le16_to_cpu(v) 20#define CF_LE_L(v) le32_to_cpu(v) 21#define CT_LE_W(v) cpu_to_le16(v) 22#define CT_LE_L(v) cpu_to_le32(v) 23 24 25#define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */ 26#define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */ 27 28/* directory limit */ 29#define FAT_MAX_DIR_ENTRIES (65536) 30#define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS) 31 32#define ATTR_NONE 0 /* no attribute bits */ 33#define ATTR_RO 1 /* read-only */ 34#define ATTR_HIDDEN 2 /* hidden */ 35#define ATTR_SYS 4 /* system */ 36#define ATTR_VOLUME 8 /* volume label */ 37#define ATTR_DIR 16 /* directory */ 38#define ATTR_ARCH 32 /* archived */ 39 40/* attribute bits that are copied "as is" */ 41#define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN) 42/* bits that are used by the Windows 95/Windows NT extended FAT */ 43#define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME) 44 45#define CASE_LOWER_BASE 8 /* base is lower case */ 46#define CASE_LOWER_EXT 16 /* extension is lower case */ 47 48#define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */ 49#define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG) 50 51#define FAT_LFN_LEN 255 /* maximum long name length */ 52#define MSDOS_NAME 11 /* maximum name length */ 53#define MSDOS_SLOTS 21 /* max # of slots for short and long names */ 54#define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */ 55#define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */ 56 57#define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \ 58 MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x)) 59 60/* start of data cluster's entry (number of reserved clusters) */ 61#define FAT_START_ENT 2 62 63/* maximum number of clusters */ 64#define MAX_FAT12 0xFF4 65#define MAX_FAT16 0xFFF4 66#define MAX_FAT32 0x0FFFFFF6 67#define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \ 68 MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12) 69 70/* bad cluster mark */ 71#define BAD_FAT12 0xFF7 72#define BAD_FAT16 0xFFF7 73#define BAD_FAT32 0x0FFFFFF7 74 75/* standard EOF */ 76#define EOF_FAT12 0xFFF 77#define EOF_FAT16 0xFFFF 78#define EOF_FAT32 0x0FFFFFFF 79 80#define FAT_ENT_FREE (0) 81#define FAT_ENT_BAD (BAD_FAT32) 82#define FAT_ENT_EOF (EOF_FAT32) 83 84#define FAT_FSINFO_SIG1 0x41615252 85#define FAT_FSINFO_SIG2 0x61417272 86#define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \ 87 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2) 88 89struct __fat_dirent { 90 long d_ino; 91 __kernel_off_t d_off; 92 unsigned short d_reclen; 93 char d_name[256]; /* We must not include limits.h! */ 94}; 95 96/* 97 * ioctl commands 98 */ 99#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct __fat_dirent[2]) 100#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct __fat_dirent[2]) 101/* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */ 102#define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32) 103#define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32) 104#define VFAT_IOCTL_GET_VOLUME_ID _IOR('r', 0x12, __u32) 105 106struct fat_boot_sector { 107 __u8 ignored[3]; /* Boot strap short or near jump */ 108 __u8 system_id[8]; /* Name - can be used to special case 109 partition manager volumes */ 110 __u8 sector_size[2]; /* bytes per logical sector */ 111 __u8 sec_per_clus; /* sectors/cluster */ 112 __le16 reserved; /* reserved sectors */ 113 __u8 fats; /* number of FATs */ 114 __u8 dir_entries[2]; /* root directory entries */ 115 __u8 sectors[2]; /* number of sectors */ 116 __u8 media; /* media code */ 117 __le16 fat_length; /* sectors/FAT */ 118 __le16 secs_track; /* sectors per track */ 119 __le16 heads; /* number of heads */ 120 __le32 hidden; /* hidden sectors (unused) */ 121 __le32 total_sect; /* number of sectors (if sectors == 0) */ 122 123 /* The following fields are only used by FAT32 */ 124 __le32 fat32_length; /* sectors/FAT */ 125 __le16 flags; /* bit 8: fat mirroring, low 4: active fat */ 126 __u8 version[2]; /* major, minor filesystem version */ 127 __le32 root_cluster; /* first cluster in root directory */ 128 __le16 info_sector; /* filesystem info sector */ 129 __le16 backup_boot; /* backup boot sector */ 130 __le16 reserved2[6]; /* Unused */ 131}; 132 133struct fat_boot_fsinfo { 134 __le32 signature1; /* 0x41615252L */ 135 __le32 reserved1[120]; /* Nothing as far as I can tell */ 136 __le32 signature2; /* 0x61417272L */ 137 __le32 free_clusters; /* Free cluster count. -1 if unknown */ 138 __le32 next_cluster; /* Most recently allocated cluster */ 139 __le32 reserved2[4]; 140}; 141 142struct fat_boot_bsx { 143 __u8 drive; /* drive number */ 144 __u8 reserved1; 145 __u8 signature; /* extended boot signature */ 146 __u8 vol_id[4]; /* volume ID */ 147 __u8 vol_label[11]; /* volume label */ 148 __u8 type[8]; /* file system type */ 149}; 150#define FAT16_BSX_OFFSET 36 /* offset of fat_boot_bsx in FAT12 and FAT16 */ 151#define FAT32_BSX_OFFSET 64 /* offset of fat_boot_bsx in FAT32 */ 152 153struct msdos_dir_entry { 154 __u8 name[MSDOS_NAME];/* name and extension */ 155 __u8 attr; /* attribute bits */ 156 __u8 lcase; /* Case for base and extension */ 157 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */ 158 __le16 ctime; /* Creation time */ 159 __le16 cdate; /* Creation date */ 160 __le16 adate; /* Last access date */ 161 __le16 starthi; /* High 16 bits of cluster in FAT32 */ 162 __le16 time,date,start;/* time, date and first cluster */ 163 __le32 size; /* file size (in bytes) */ 164}; 165 166/* Up to 13 characters of the name */ 167struct msdos_dir_slot { 168 __u8 id; /* sequence number for slot */ 169 __u8 name0_4[10]; /* first 5 characters in name */ 170 __u8 attr; /* attribute byte */ 171 __u8 reserved; /* always 0 */ 172 __u8 alias_checksum; /* checksum for 8.3 alias */ 173 __u8 name5_10[12]; /* 6 more characters in name */ 174 __le16 start; /* starting cluster number, 0 in long slots */ 175 __u8 name11_12[4]; /* last 2 characters in name */ 176}; 177 178#ifdef __KERNEL__ 179/* media of boot sector */ 180static inline int fat_valid_media(u8 media) 181{ 182 return 0xf8 <= media || media == 0xf0; 183} 184#endif /* !__KERNEL__ */ 185#endif /* !_LINUX_MSDOS_FS_H */ 186