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      1 #ifndef _UAPI_LINUX_MSDOS_FS_H
      2 #define _UAPI_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 #define MSDOS_ROOT_INO	 1	/* The root inode number */
     25 #define MSDOS_FSINFO_INO 2	/* Used for managing the FSINFO block */
     26 
     27 #define MSDOS_DIR_BITS	5	/* log2(sizeof(struct msdos_dir_entry)) */
     28 
     29 /* directory limit */
     30 #define FAT_MAX_DIR_ENTRIES	(65536)
     31 #define FAT_MAX_DIR_SIZE	(FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
     32 
     33 #define ATTR_NONE	0	/* no attribute bits */
     34 #define ATTR_RO		1	/* read-only */
     35 #define ATTR_HIDDEN	2	/* hidden */
     36 #define ATTR_SYS	4	/* system */
     37 #define ATTR_VOLUME	8	/* volume label */
     38 #define ATTR_DIR	16	/* directory */
     39 #define ATTR_ARCH	32	/* archived */
     40 
     41 /* attribute bits that are copied "as is" */
     42 #define ATTR_UNUSED	(ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
     43 /* bits that are used by the Windows 95/Windows NT extended FAT */
     44 #define ATTR_EXT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
     45 
     46 #define CASE_LOWER_BASE	8	/* base is lower case */
     47 #define CASE_LOWER_EXT	16	/* extension is lower case */
     48 
     49 #define DELETED_FLAG	0xe5	/* marks file as deleted when in name[0] */
     50 #define IS_FREE(n)	(!*(n) || *(n) == DELETED_FLAG)
     51 
     52 #define FAT_LFN_LEN	255	/* maximum long name length */
     53 #define MSDOS_NAME	11	/* maximum name length */
     54 #define MSDOS_SLOTS	21	/* max # of slots for short and long names */
     55 #define MSDOS_DOT	".          "	/* ".", padded to MSDOS_NAME chars */
     56 #define MSDOS_DOTDOT	"..         "	/* "..", padded to MSDOS_NAME chars */
     57 
     58 #define FAT_FIRST_ENT(s, x)	((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
     59 	MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
     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 #define MAX_FAT(s)	(MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
     69 	MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
     70 
     71 /* bad cluster mark */
     72 #define BAD_FAT12	0xFF7
     73 #define BAD_FAT16	0xFFF7
     74 #define BAD_FAT32	0x0FFFFFF7
     75 
     76 /* standard EOF */
     77 #define EOF_FAT12	0xFFF
     78 #define EOF_FAT16	0xFFFF
     79 #define EOF_FAT32	0x0FFFFFFF
     80 
     81 #define FAT_ENT_FREE	(0)
     82 #define FAT_ENT_BAD	(BAD_FAT32)
     83 #define FAT_ENT_EOF	(EOF_FAT32)
     84 
     85 #define FAT_FSINFO_SIG1	0x41615252
     86 #define FAT_FSINFO_SIG2	0x61417272
     87 #define IS_FSINFO(x)	(le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
     88 			 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
     89 
     90 #define FAT_STATE_DIRTY 0x01
     91 
     92 struct __fat_dirent {
     93 	long		d_ino;
     94 	__kernel_off_t	d_off;
     95 	unsigned short	d_reclen;
     96 	char		d_name[256]; /* We must not include limits.h! */
     97 };
     98 
     99 /*
    100  * ioctl commands
    101  */
    102 #define VFAT_IOCTL_READDIR_BOTH		_IOR('r', 1, struct __fat_dirent[2])
    103 #define VFAT_IOCTL_READDIR_SHORT	_IOR('r', 2, struct __fat_dirent[2])
    104 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
    105 #define FAT_IOCTL_GET_ATTRIBUTES	_IOR('r', 0x10, __u32)
    106 #define FAT_IOCTL_SET_ATTRIBUTES	_IOW('r', 0x11, __u32)
    107 /*Android kernel has used 0x12, so we use 0x13*/
    108 #define FAT_IOCTL_GET_VOLUME_ID		_IOR('r', 0x13, __u32)
    109 
    110 struct fat_boot_sector {
    111 	__u8	ignored[3];	/* Boot strap short or near jump */
    112 	__u8	system_id[8];	/* Name - can be used to special case
    113 				   partition manager volumes */
    114 	__u8	sector_size[2];	/* bytes per logical sector */
    115 	__u8	sec_per_clus;	/* sectors/cluster */
    116 	__le16	reserved;	/* reserved sectors */
    117 	__u8	fats;		/* number of FATs */
    118 	__u8	dir_entries[2];	/* root directory entries */
    119 	__u8	sectors[2];	/* number of sectors */
    120 	__u8	media;		/* media code */
    121 	__le16	fat_length;	/* sectors/FAT */
    122 	__le16	secs_track;	/* sectors per track */
    123 	__le16	heads;		/* number of heads */
    124 	__le32	hidden;		/* hidden sectors (unused) */
    125 	__le32	total_sect;	/* number of sectors (if sectors == 0) */
    126 
    127 	union {
    128 		struct {
    129 			/*  Extended BPB Fields for FAT16 */
    130 			__u8	drive_number;	/* Physical drive number */
    131 			__u8	state;		/* undocumented, but used
    132 						   for mount state. */
    133 			__u8	signature;  /* extended boot signature */
    134 			__u8	vol_id[4];	/* volume ID */
    135 			__u8	vol_label[11];	/* volume label */
    136 			__u8	fs_type[8];		/* file system type */
    137 			/* other fields are not added here */
    138 		} fat16;
    139 
    140 		struct {
    141 			/* only used by FAT32 */
    142 			__le32	length;		/* sectors/FAT */
    143 			__le16	flags;		/* bit 8: fat mirroring,
    144 						   low 4: active fat */
    145 			__u8	version[2];	/* major, minor filesystem
    146 						   version */
    147 			__le32	root_cluster;	/* first cluster in
    148 						   root directory */
    149 			__le16	info_sector;	/* filesystem info sector */
    150 			__le16	backup_boot;	/* backup boot sector */
    151 			__le16	reserved2[6];	/* Unused */
    152 			/* Extended BPB Fields for FAT32 */
    153 			__u8	drive_number;   /* Physical drive number */
    154 			__u8    state;       	/* undocumented, but used
    155 						   for mount state. */
    156 			__u8	signature;  /* extended boot signature */
    157 			__u8	vol_id[4];	/* volume ID */
    158 			__u8	vol_label[11];	/* volume label */
    159 			__u8	fs_type[8];		/* file system type */
    160 			/* other fields are not added here */
    161 		} fat32;
    162 	};
    163 };
    164 
    165 struct fat_boot_fsinfo {
    166 	__le32   signature1;	/* 0x41615252L */
    167 	__le32   reserved1[120];	/* Nothing as far as I can tell */
    168 	__le32   signature2;	/* 0x61417272L */
    169 	__le32   free_clusters;	/* Free cluster count.  -1 if unknown */
    170 	__le32   next_cluster;	/* Most recently allocated cluster */
    171 	__le32   reserved2[4];
    172 };
    173 
    174 struct msdos_dir_entry {
    175 	__u8	name[MSDOS_NAME];/* name and extension */
    176 	__u8	attr;		/* attribute bits */
    177 	__u8    lcase;		/* Case for base and extension */
    178 	__u8	ctime_cs;	/* Creation time, centiseconds (0-199) */
    179 	__le16	ctime;		/* Creation time */
    180 	__le16	cdate;		/* Creation date */
    181 	__le16	adate;		/* Last access date */
    182 	__le16	starthi;	/* High 16 bits of cluster in FAT32 */
    183 	__le16	time,date,start;/* time, date and first cluster */
    184 	__le32	size;		/* file size (in bytes) */
    185 };
    186 
    187 /* Up to 13 characters of the name */
    188 struct msdos_dir_slot {
    189 	__u8    id;		/* sequence number for slot */
    190 	__u8    name0_4[10];	/* first 5 characters in name */
    191 	__u8    attr;		/* attribute byte */
    192 	__u8    reserved;	/* always 0 */
    193 	__u8    alias_checksum;	/* checksum for 8.3 alias */
    194 	__u8    name5_10[12];	/* 6 more characters in name */
    195 	__le16   start;		/* starting cluster number, 0 in long slots */
    196 	__u8    name11_12[4];	/* last 2 characters in name */
    197 };
    198 
    199 #endif /* _UAPI_LINUX_MSDOS_FS_H */
    200