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
92struct __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
110struct 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 fiealds 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 fiealds are not added here */
161		} fat32;
162	};
163};
164
165struct 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
174struct 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 */
188struct 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