1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _LINUX_MSDOS_FS_H
#define _LINUX_MSDOS_FS_H
#include <linux/types.h>
#include <linux/magic.h>
#include <asm/byteorder.h>
/*
* The MS-DOS filesystem constants/structures
*/
#ifndef SECTOR_SIZE
#define SECTOR_SIZE 512 /* sector size (bytes) */
#endif
#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 */
/* 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
/* 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[MSDOS_NAME]; /* volume label */
__u8 fs_type[8]; /* file system type */
/* other fields 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[MSDOS_NAME]; /* volume label */
__u8 fs_type[8]; /* file system type */
/* other fields 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 /* _LINUX_MSDOS_FS_H */
|
