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