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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
93struct __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
111struct 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
166struct 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
175struct 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 */
189struct 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 */