LXR linux/include/uapi/linux/msdos

   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2#ifndef _UAPI_LINUX_MSDOS_FS_H
   3#define _UAPI_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#define FAT_FIRST_ENT(s, x)     ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
  62        MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
  63
  64/* start of data cluster's entry (number of reserved clusters) */
  65#define FAT_START_ENT   2
  66
  67/* maximum number of clusters */
  68#define MAX_FAT12       0xFF4
  69#define MAX_FAT16       0xFFF4
  70#define MAX_FAT32       0x0FFFFFF6
  71#define MAX_FAT(s)      (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
  72        MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
  73
  74/* bad cluster mark */
  75#define BAD_FAT12       0xFF7
  76#define BAD_FAT16       0xFFF7
  77#define BAD_FAT32       0x0FFFFFF7
  78
  79/* standard EOF */
  80#define EOF_FAT12       0xFFF
  81#define EOF_FAT16       0xFFFF
  82#define EOF_FAT32       0x0FFFFFFF
  83
  84#define FAT_ENT_FREE    (0)
  85#define FAT_ENT_BAD     (BAD_FAT32)
  86#define FAT_ENT_EOF     (EOF_FAT32)
  87
  88#define FAT_FSINFO_SIG1 0x41615252
  89#define FAT_FSINFO_SIG2 0x61417272
  90#define IS_FSINFO(x)    (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
  91                         && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
  92
  93#define FAT_STATE_DIRTY 0x01
  94
  95struct __fat_dirent {
  96        long            d_ino;
  97        __kernel_off_t  d_off;
  98        unsigned short  d_reclen;
  99        char            d_name[256]; /* We must not include limits.h! */
 100};
 101
 102/*
 103 * ioctl commands
 104 */
 105#define VFAT_IOCTL_READDIR_BOTH         _IOR('r', 1, struct __fat_dirent[2])
 106#define VFAT_IOCTL_READDIR_SHORT        _IOR('r', 2, struct __fat_dirent[2])
 107/* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
 108#define FAT_IOCTL_GET_ATTRIBUTES        _IOR('r', 0x10, __u32)
 109#define FAT_IOCTL_SET_ATTRIBUTES        _IOW('r', 0x11, __u32)
 110/*Android kernel has used 0x12, so we use 0x13*/
 111#define FAT_IOCTL_GET_VOLUME_ID         _IOR('r', 0x13, __u32)
 112
 113struct fat_boot_sector {
 114        __u8    ignored[3];     /* Boot strap short or near jump */
 115        __u8    system_id[8];   /* Name - can be used to special case
 116                                   partition manager volumes */
 117        __u8    sector_size[2]; /* bytes per logical sector */
 118        __u8    sec_per_clus;   /* sectors/cluster */
 119        __le16  reserved;       /* reserved sectors */
 120        __u8    fats;           /* number of FATs */
 121        __u8    dir_entries[2]; /* root directory entries */
 122        __u8    sectors[2];     /* number of sectors */
 123        __u8    media;          /* media code */
 124        __le16  fat_length;     /* sectors/FAT */
 125        __le16  secs_track;     /* sectors per track */
 126        __le16  heads;          /* number of heads */
 127        __le32  hidden;         /* hidden sectors (unused) */
 128        __le32  total_sect;     /* number of sectors (if sectors == 0) */
 129
 130        union {
 131                struct {
 132                        /*  Extended BPB Fields for FAT16 */
 133                        __u8    drive_number;   /* Physical drive number */
 134                        __u8    state;          /* undocumented, but used
 135                                                   for mount state. */
 136                        __u8    signature;  /* extended boot signature */
 137                        __u8    vol_id[4];      /* volume ID */
 138                        __u8    vol_label[11];  /* volume label */
 139                        __u8    fs_type[8];             /* file system type */
 140                        /* other fields are not added here */
 141                } fat16;
 142
 143                struct {
 144                        /* only used by FAT32 */
 145                        __le32  length;         /* sectors/FAT */
 146                        __le16  flags;          /* bit 8: fat mirroring,
 147                                                   low 4: active fat */
 148                        __u8    version[2];     /* major, minor filesystem
 149                                                   version */
 150                        __le32  root_cluster;   /* first cluster in
 151                                                   root directory */
 152                        __le16  info_sector;    /* filesystem info sector */
 153                        __le16  backup_boot;    /* backup boot sector */
 154                        __le16  reserved2[6];   /* Unused */
 155                        /* Extended BPB Fields for FAT32 */
 156                        __u8    drive_number;   /* Physical drive number */
 157                        __u8    state;          /* undocumented, but used
 158                                                   for mount state. */
 159                        __u8    signature;  /* extended boot signature */
 160                        __u8    vol_id[4];      /* volume ID */
 161                        __u8    vol_label[11];  /* volume label */
 162                        __u8    fs_type[8];             /* file system type */
 163                        /* other fields are not added here */
 164                } fat32;
 165        };
 166};
 167
 168struct fat_boot_fsinfo {
 169        __le32   signature1;    /* 0x41615252L */
 170        __le32   reserved1[120];        /* Nothing as far as I can tell */
 171        __le32   signature2;    /* 0x61417272L */
 172        __le32   free_clusters; /* Free cluster count.  -1 if unknown */
 173        __le32   next_cluster;  /* Most recently allocated cluster */
 174        __le32   reserved2[4];
 175};
 176
 177struct msdos_dir_entry {
 178        __u8    name[MSDOS_NAME];/* name and extension */
 179        __u8    attr;           /* attribute bits */
 180        __u8    lcase;          /* Case for base and extension */
 181        __u8    ctime_cs;       /* Creation time, centiseconds (0-199) */
 182        __le16  ctime;          /* Creation time */
 183        __le16  cdate;          /* Creation date */
 184        __le16  adate;          /* Last access date */
 185        __le16  starthi;        /* High 16 bits of cluster in FAT32 */
 186        __le16  time,date,start;/* time, date and first cluster */
 187        __le32  size;           /* file size (in bytes) */
 188};
 189
 190/* Up to 13 characters of the name */
 191struct msdos_dir_slot {
 192        __u8    id;             /* sequence number for slot */
 193        __u8    name0_4[10];    /* first 5 characters in name */
 194        __u8    attr;           /* attribute byte */
 195        __u8    reserved;       /* always 0 */
 196        __u8    alias_checksum; /* checksum for 8.3 alias */
 197        __u8    name5_10[12];   /* 6 more characters in name */
 198        __le16   start;         /* starting cluster number, 0 in long slots */
 199        __u8    name11_12[4];   /* last 2 characters in name */
 200};
 201
 202#endif /* _UAPI_LINUX_MSDOS_FS_H */
 203