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      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 #define SECTOR_SIZE	512		/* sector size (bytes) */
     14 #define SECTOR_BITS	9		/* log2(SECTOR_SIZE) */
     15 #define MSDOS_DPB	(MSDOS_DPS)	/* dir entries per block */
     16 #define MSDOS_DPB_BITS	4		/* log2(MSDOS_DPB) */
     17 #define MSDOS_DPS	(SECTOR_SIZE / sizeof(struct msdos_dir_entry))
     18 #define MSDOS_DPS_BITS	4		/* log2(MSDOS_DPS) */
     19 #define MSDOS_LONGNAME	256		/* maximum name length */
     20 #define CF_LE_W(v)	le16_to_cpu(v)
     21 #define CF_LE_L(v)	le32_to_cpu(v)
     22 #define CT_LE_W(v)	cpu_to_le16(v)
     23 #define CT_LE_L(v)	cpu_to_le32(v)
     24 
     25 #define MSDOS_ROOT_INO	 1	/* The root inode number */
     26 #define MSDOS_FSINFO_INO 2	/* Used for managing the FSINFO block */
     27 
     28 #define MSDOS_DIR_BITS	5	/* log2(sizeof(struct msdos_dir_entry)) */
     29 
     30 /* directory limit */
     31 #define FAT_MAX_DIR_ENTRIES	(65536)
     32 #define FAT_MAX_DIR_SIZE	(FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
     33 
     34 #define ATTR_NONE	0	/* no attribute bits */
     35 #define ATTR_RO		1	/* read-only */
     36 #define ATTR_HIDDEN	2	/* hidden */
     37 #define ATTR_SYS	4	/* system */
     38 #define ATTR_VOLUME	8	/* volume label */
     39 #define ATTR_DIR	16	/* directory */
     40 #define ATTR_ARCH	32	/* archived */
     41 
     42 /* attribute bits that are copied "as is" */
     43 #define ATTR_UNUSED	(ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
     44 /* bits that are used by the Windows 95/Windows NT extended FAT */
     45 #define ATTR_EXT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
     46 
     47 #define CASE_LOWER_BASE	8	/* base is lower case */
     48 #define CASE_LOWER_EXT	16	/* extension is lower case */
     49 
     50 #define DELETED_FLAG	0xe5	/* marks file as deleted when in name[0] */
     51 #define IS_FREE(n)	(!*(n) || *(n) == DELETED_FLAG)
     52 
     53 #define FAT_LFN_LEN	255	/* maximum long name length */
     54 #define MSDOS_NAME	11	/* maximum name length */
     55 #define MSDOS_SLOTS	21	/* max # of slots for short and long names */
     56 #define MSDOS_DOT	".          "	/* ".", padded to MSDOS_NAME chars */
     57 #define MSDOS_DOTDOT	"..         "	/* "..", padded to MSDOS_NAME chars */
     58 
     59 #define FAT_FIRST_ENT(s, x)	((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
     60 	MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
     61 
     62 /* start of data cluster's entry (number of reserved clusters) */
     63 #define FAT_START_ENT	2
     64 
     65 /* maximum number of clusters */
     66 #define MAX_FAT12	0xFF4
     67 #define MAX_FAT16	0xFFF4
     68 #define MAX_FAT32	0x0FFFFFF6
     69 #define MAX_FAT(s)	(MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
     70 	MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
     71 
     72 /* bad cluster mark */
     73 #define BAD_FAT12	0xFF7
     74 #define BAD_FAT16	0xFFF7
     75 #define BAD_FAT32	0x0FFFFFF7
     76 
     77 /* standard EOF */
     78 #define EOF_FAT12	0xFFF
     79 #define EOF_FAT16	0xFFFF
     80 #define EOF_FAT32	0x0FFFFFFF
     81 
     82 #define FAT_ENT_FREE	(0)
     83 #define FAT_ENT_BAD	(BAD_FAT32)
     84 #define FAT_ENT_EOF	(EOF_FAT32)
     85 
     86 #define FAT_FSINFO_SIG1	0x41615252
     87 #define FAT_FSINFO_SIG2	0x61417272
     88 #define IS_FSINFO(x)	(le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
     89 			 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
     90 
     91 #define FAT_STATE_DIRTY 0x01
     92 
     93 struct __fat_dirent {
     94 	long		d_ino;
     95 	__kernel_off_t	d_off;
     96 	unsigned short	d_reclen;
     97 	char		d_name[256]; /* We must not include limits.h! */
     98 };
     99 
    100 /*
    101  * ioctl commands
    102  */
    103 #define VFAT_IOCTL_READDIR_BOTH		_IOR('r', 1, struct __fat_dirent[2])
    104 #define VFAT_IOCTL_READDIR_SHORT	_IOR('r', 2, struct __fat_dirent[2])
    105 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
    106 #define FAT_IOCTL_GET_ATTRIBUTES	_IOR('r', 0x10, __u32)
    107 #define FAT_IOCTL_SET_ATTRIBUTES	_IOW('r', 0x11, __u32)
    108 /*Android kernel has used 0x12, so we use 0x13*/
    109 #define FAT_IOCTL_GET_VOLUME_ID		_IOR('r', 0x13, __u32)
    110 
    111 struct fat_boot_sector {
    112 	__u8	ignored[3];	/* Boot strap short or near jump */
    113 	__u8	system_id[8];	/* Name - can be used to special case
    114 				   partition manager volumes */
    115 	__u8	sector_size[2];	/* bytes per logical sector */
    116 	__u8	sec_per_clus;	/* sectors/cluster */
    117 	__le16	reserved;	/* reserved sectors */
    118 	__u8	fats;		/* number of FATs */
    119 	__u8	dir_entries[2];	/* root directory entries */
    120 	__u8	sectors[2];	/* number of sectors */
    121 	__u8	media;		/* media code */
    122 	__le16	fat_length;	/* sectors/FAT */
    123 	__le16	secs_track;	/* sectors per track */
    124 	__le16	heads;		/* number of heads */
    125 	__le32	hidden;		/* hidden sectors (unused) */
    126 	__le32	total_sect;	/* number of sectors (if sectors == 0) */
    127 
    128 	union {
    129 		struct {
    130 			/*  Extended BPB Fields for FAT16 */
    131 			__u8	drive_number;	/* Physical drive number */
    132 			__u8	state;		/* undocumented, but used
    133 						   for mount state. */
    134 			__u8	signature;  /* extended boot signature */
    135 			__u8	vol_id[4];	/* volume ID */
    136 			__u8	vol_label[11];	/* volume label */
    137 			__u8	fs_type[8];		/* file system type */
    138 			/* other fields are not added here */
    139 		} fat16;
    140 
    141 		struct {
    142 			/* only used by FAT32 */
    143 			__le32	length;		/* sectors/FAT */
    144 			__le16	flags;		/* bit 8: fat mirroring,
    145 						   low 4: active fat */
    146 			__u8	version[2];	/* major, minor filesystem
    147 						   version */
    148 			__le32	root_cluster;	/* first cluster in
    149 						   root directory */
    150 			__le16	info_sector;	/* filesystem info sector */
    151 			__le16	backup_boot;	/* backup boot sector */
    152 			__le16	reserved2[6];	/* Unused */
    153 			/* Extended BPB Fields for FAT32 */
    154 			__u8	drive_number;   /* Physical drive number */
    155 			__u8    state;       	/* undocumented, but used
    156 						   for mount state. */
    157 			__u8	signature;  /* extended boot signature */
    158 			__u8	vol_id[4];	/* volume ID */
    159 			__u8	vol_label[11];	/* volume label */
    160 			__u8	fs_type[8];		/* file system type */
    161 			/* other fields are not added here */
    162 		} fat32;
    163 	};
    164 };
    165 
    166 struct fat_boot_fsinfo {
    167 	__le32   signature1;	/* 0x41615252L */
    168 	__le32   reserved1[120];	/* Nothing as far as I can tell */
    169 	__le32   signature2;	/* 0x61417272L */
    170 	__le32   free_clusters;	/* Free cluster count.  -1 if unknown */
    171 	__le32   next_cluster;	/* Most recently allocated cluster */
    172 	__le32   reserved2[4];
    173 };
    174 
    175 struct msdos_dir_entry {
    176 	__u8	name[MSDOS_NAME];/* name and extension */
    177 	__u8	attr;		/* attribute bits */
    178 	__u8    lcase;		/* Case for base and extension */
    179 	__u8	ctime_cs;	/* Creation time, centiseconds (0-199) */
    180 	__le16	ctime;		/* Creation time */
    181 	__le16	cdate;		/* Creation date */
    182 	__le16	adate;		/* Last access date */
    183 	__le16	starthi;	/* High 16 bits of cluster in FAT32 */
    184 	__le16	time,date,start;/* time, date and first cluster */
    185 	__le32	size;		/* file size (in bytes) */
    186 };
    187 
    188 /* Up to 13 characters of the name */
    189 struct msdos_dir_slot {
    190 	__u8    id;		/* sequence number for slot */
    191 	__u8    name0_4[10];	/* first 5 characters in name */
    192 	__u8    attr;		/* attribute byte */
    193 	__u8    reserved;	/* always 0 */
    194 	__u8    alias_checksum;	/* checksum for 8.3 alias */
    195 	__u8    name5_10[12];	/* 6 more characters in name */
    196 	__le16   start;		/* starting cluster number, 0 in long slots */
    197 	__u8    name11_12[4];	/* last 2 characters in name */
    198 };
    199 
    200 #endif /* _UAPI_LINUX_MSDOS_FS_H */
    201