root/include/uapi/linux/msdos_fs.h

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INCLUDED FROM


#ifndef _UAPI_LINUX_MSDOS_FS_H
#define _UAPI_LINUX_MSDOS_FS_H

#include <linux/types.h>
#include <linux/magic.h>
#include <asm/byteorder.h>

/*
 * The MS-DOS filesystem constants/structures
 */

#define SECTOR_SIZE     512             /* sector size (bytes) */
#define SECTOR_BITS     9               /* log2(SECTOR_SIZE) */
#define MSDOS_DPB       (MSDOS_DPS)     /* dir entries per block */
#define MSDOS_DPB_BITS  4               /* log2(MSDOS_DPB) */
#define MSDOS_DPS       (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
#define MSDOS_DPS_BITS  4               /* log2(MSDOS_DPS) */
#define MSDOS_LONGNAME  256             /* maximum name length */
#define CF_LE_W(v)      le16_to_cpu(v)
#define CF_LE_L(v)      le32_to_cpu(v)
#define CT_LE_W(v)      cpu_to_le16(v)
#define CT_LE_L(v)      cpu_to_le32(v)

#define MSDOS_ROOT_INO   1      /* The root inode number */
#define MSDOS_FSINFO_INO 2      /* Used for managing the FSINFO block */

#define MSDOS_DIR_BITS  5       /* log2(sizeof(struct msdos_dir_entry)) */

/* directory limit */
#define FAT_MAX_DIR_ENTRIES     (65536)
#define FAT_MAX_DIR_SIZE        (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)

#define ATTR_NONE       0       /* no attribute bits */
#define ATTR_RO         1       /* read-only */
#define ATTR_HIDDEN     2       /* hidden */
#define ATTR_SYS        4       /* system */
#define ATTR_VOLUME     8       /* volume label */
#define ATTR_DIR        16      /* directory */
#define ATTR_ARCH       32      /* archived */

/* attribute bits that are copied "as is" */
#define ATTR_UNUSED     (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
/* bits that are used by the Windows 95/Windows NT extended FAT */
#define ATTR_EXT        (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)

#define CASE_LOWER_BASE 8       /* base is lower case */
#define CASE_LOWER_EXT  16      /* extension is lower case */

#define DELETED_FLAG    0xe5    /* marks file as deleted when in name[0] */
#define IS_FREE(n)      (!*(n) || *(n) == DELETED_FLAG)

#define FAT_LFN_LEN     255     /* maximum long name length */
#define MSDOS_NAME      11      /* maximum name length */
#define MSDOS_SLOTS     21      /* max # of slots for short and long names */
#define MSDOS_DOT       ".          "   /* ".", padded to MSDOS_NAME chars */
#define MSDOS_DOTDOT    "..         "   /* "..", padded to MSDOS_NAME chars */

#define FAT_FIRST_ENT(s, x)     ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
        MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))

/* start of data cluster's entry (number of reserved clusters) */
#define FAT_START_ENT   2

/* maximum number of clusters */
#define MAX_FAT12       0xFF4
#define MAX_FAT16       0xFFF4
#define MAX_FAT32       0x0FFFFFF6
#define MAX_FAT(s)      (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
        MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)

/* bad cluster mark */
#define BAD_FAT12       0xFF7
#define BAD_FAT16       0xFFF7
#define BAD_FAT32       0x0FFFFFF7

/* standard EOF */
#define EOF_FAT12       0xFFF
#define EOF_FAT16       0xFFFF
#define EOF_FAT32       0x0FFFFFFF

#define FAT_ENT_FREE    (0)
#define FAT_ENT_BAD     (BAD_FAT32)
#define FAT_ENT_EOF     (EOF_FAT32)

#define FAT_FSINFO_SIG1 0x41615252
#define FAT_FSINFO_SIG2 0x61417272
#define IS_FSINFO(x)    (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
                         && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)

#define FAT_STATE_DIRTY 0x01

struct __fat_dirent {
        long            d_ino;
        __kernel_off_t  d_off;
        unsigned short  d_reclen;
        char            d_name[256]; /* We must not include limits.h! */
};

/*
 * ioctl commands
 */
#define VFAT_IOCTL_READDIR_BOTH         _IOR('r', 1, struct __fat_dirent[2])
#define VFAT_IOCTL_READDIR_SHORT        _IOR('r', 2, struct __fat_dirent[2])
/* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
#define FAT_IOCTL_GET_ATTRIBUTES        _IOR('r', 0x10, __u32)
#define FAT_IOCTL_SET_ATTRIBUTES        _IOW('r', 0x11, __u32)
/*Android kernel has used 0x12, so we use 0x13*/
#define FAT_IOCTL_GET_VOLUME_ID         _IOR('r', 0x13, __u32)

struct fat_boot_sector {
        __u8    ignored[3];     /* Boot strap short or near jump */
        __u8    system_id[8];   /* Name - can be used to special case
                                   partition manager volumes */
        __u8    sector_size[2]; /* bytes per logical sector */
        __u8    sec_per_clus;   /* sectors/cluster */
        __le16  reserved;       /* reserved sectors */
        __u8    fats;           /* number of FATs */
        __u8    dir_entries[2]; /* root directory entries */
        __u8    sectors[2];     /* number of sectors */
        __u8    media;          /* media code */
        __le16  fat_length;     /* sectors/FAT */
        __le16  secs_track;     /* sectors per track */
        __le16  heads;          /* number of heads */
        __le32  hidden;         /* hidden sectors (unused) */
        __le32  total_sect;     /* number of sectors (if sectors == 0) */

        union {
                struct {
                        /*  Extended BPB Fields for FAT16 */
                        __u8    drive_number;   /* Physical drive number */
                        __u8    state;          /* undocumented, but used
                                                   for mount state. */
                        __u8    signature;  /* extended boot signature */
                        __u8    vol_id[4];      /* volume ID */
                        __u8    vol_label[11];  /* volume label */
                        __u8    fs_type[8];             /* file system type */
                        /* other fiealds are not added here */
                } fat16;

                struct {
                        /* only used by FAT32 */
                        __le32  length;         /* sectors/FAT */
                        __le16  flags;          /* bit 8: fat mirroring,
                                                   low 4: active fat */
                        __u8    version[2];     /* major, minor filesystem
                                                   version */
                        __le32  root_cluster;   /* first cluster in
                                                   root directory */
                        __le16  info_sector;    /* filesystem info sector */
                        __le16  backup_boot;    /* backup boot sector */
                        __le16  reserved2[6];   /* Unused */
                        /* Extended BPB Fields for FAT32 */
                        __u8    drive_number;   /* Physical drive number */
                        __u8    state;          /* undocumented, but used
                                                   for mount state. */
                        __u8    signature;  /* extended boot signature */
                        __u8    vol_id[4];      /* volume ID */
                        __u8    vol_label[11];  /* volume label */
                        __u8    fs_type[8];             /* file system type */
                        /* other fiealds are not added here */
                } fat32;
        };
};

struct fat_boot_fsinfo {
        __le32   signature1;    /* 0x41615252L */
        __le32   reserved1[120];        /* Nothing as far as I can tell */
        __le32   signature2;    /* 0x61417272L */
        __le32   free_clusters; /* Free cluster count.  -1 if unknown */
        __le32   next_cluster;  /* Most recently allocated cluster */
        __le32   reserved2[4];
};

struct msdos_dir_entry {
        __u8    name[MSDOS_NAME];/* name and extension */
        __u8    attr;           /* attribute bits */
        __u8    lcase;          /* Case for base and extension */
        __u8    ctime_cs;       /* Creation time, centiseconds (0-199) */
        __le16  ctime;          /* Creation time */
        __le16  cdate;          /* Creation date */
        __le16  adate;          /* Last access date */
        __le16  starthi;        /* High 16 bits of cluster in FAT32 */
        __le16  time,date,start;/* time, date and first cluster */
        __le32  size;           /* file size (in bytes) */
};

/* Up to 13 characters of the name */
struct msdos_dir_slot {
        __u8    id;             /* sequence number for slot */
        __u8    name0_4[10];    /* first 5 characters in name */
        __u8    attr;           /* attribute byte */
        __u8    reserved;       /* always 0 */
        __u8    alias_checksum; /* checksum for 8.3 alias */
        __u8    name5_10[12];   /* 6 more characters in name */
        __le16   start;         /* starting cluster number, 0 in long slots */
        __u8    name11_12[4];   /* last 2 characters in name */
};

#endif /* _UAPI_LINUX_MSDOS_FS_H */

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