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1 : #ifndef _LINUX_MSDOS_FS_H
2 : #define _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 CF_LE_W(v) le16_to_cpu(v)
19 : #define CF_LE_L(v) le32_to_cpu(v)
20 : #define CT_LE_W(v) cpu_to_le16(v)
21 : #define CT_LE_L(v) cpu_to_le32(v)
22 :
23 :
24 : #define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */
25 : #define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */
26 :
27 : /* directory limit */
28 : #define FAT_MAX_DIR_ENTRIES (65536)
29 : #define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
30 :
31 : #define ATTR_NONE 0 /* no attribute bits */
32 : #define ATTR_RO 1 /* read-only */
33 : #define ATTR_HIDDEN 2 /* hidden */
34 : #define ATTR_SYS 4 /* system */
35 : #define ATTR_VOLUME 8 /* volume label */
36 : #define ATTR_DIR 16 /* directory */
37 : #define ATTR_ARCH 32 /* archived */
38 :
39 : /* attribute bits that are copied "as is" */
40 : #define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
41 : /* bits that are used by the Windows 95/Windows NT extended FAT */
42 : #define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
43 :
44 : #define CASE_LOWER_BASE 8 /* base is lower case */
45 : #define CASE_LOWER_EXT 16 /* extension is lower case */
46 :
47 : #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */
48 : #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG)
49 :
50 : #define MSDOS_NAME 11 /* maximum name length */
51 : #define MSDOS_LONGNAME 256 /* maximum name length */
52 : #define MSDOS_SLOTS 21 /* max # of slots for short and long names */
53 : #define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */
54 : #define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */
55 :
56 : #define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
57 : MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
58 :
59 : /* start of data cluster's entry (number of reserved clusters) */
60 : #define FAT_START_ENT 2
61 :
62 : /* maximum number of clusters */
63 : #define MAX_FAT12 0xFF4
64 : #define MAX_FAT16 0xFFF4
65 : #define MAX_FAT32 0x0FFFFFF6
66 : #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
67 : MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
68 :
69 : /* bad cluster mark */
70 : #define BAD_FAT12 0xFF7
71 : #define BAD_FAT16 0xFFF7
72 : #define BAD_FAT32 0x0FFFFFF7
73 :
74 : /* standard EOF */
75 : #define EOF_FAT12 0xFFF
76 : #define EOF_FAT16 0xFFFF
77 : #define EOF_FAT32 0x0FFFFFFF
78 :
79 : #define FAT_ENT_FREE (0)
80 : #define FAT_ENT_BAD (BAD_FAT32)
81 : #define FAT_ENT_EOF (EOF_FAT32)
82 :
83 : #define FAT_FSINFO_SIG1 0x41615252
84 : #define FAT_FSINFO_SIG2 0x61417272
85 : #define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
86 : && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
87 :
88 : struct __fat_dirent {
89 : long d_ino;
90 : __kernel_off_t d_off;
91 : unsigned short d_reclen;
92 : char d_name[256]; /* We must not include limits.h! */
93 : };
94 1 :
95 : /*
96 : * ioctl commands
97 : */
98 : #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct __fat_dirent[2])
99 : #define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct __fat_dirent[2])
100 : /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
101 : #define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32)
102 : #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32)
103 :
104 : struct fat_boot_sector {
105 : __u8 ignored[3]; /* Boot strap short or near jump */
106 : __u8 system_id[8]; /* Name - can be used to special case
107 : partition manager volumes */
108 : __u8 sector_size[2]; /* bytes per logical sector */
109 : __u8 sec_per_clus; /* sectors/cluster */
110 : __le16 reserved; /* reserved sectors */
111 : __u8 fats; /* number of FATs */
112 : __u8 dir_entries[2]; /* root directory entries */
113 : __u8 sectors[2]; /* number of sectors */
114 : __u8 media; /* media code */
115 : __le16 fat_length; /* sectors/FAT */
116 : __le16 secs_track; /* sectors per track */
117 : __le16 heads; /* number of heads */
118 : __le32 hidden; /* hidden sectors (unused) */
119 : __le32 total_sect; /* number of sectors (if sectors == 0) */
120 :
121 : /* The following fields are only used by FAT32 */
122 : __le32 fat32_length; /* sectors/FAT */
123 : __le16 flags; /* bit 8: fat mirroring, low 4: active fat */
124 : __u8 version[2]; /* major, minor filesystem version */
125 : __le32 root_cluster; /* first cluster in root directory */
126 : __le16 info_sector; /* filesystem info sector */
127 : __le16 backup_boot; /* backup boot sector */
128 : __le16 reserved2[6]; /* Unused */
129 : };
130 1 :
131 : struct fat_boot_fsinfo {
132 : __le32 signature1; /* 0x41615252L */
133 : __le32 reserved1[120]; /* Nothing as far as I can tell */
134 : __le32 signature2; /* 0x61417272L */
135 : __le32 free_clusters; /* Free cluster count. -1 if unknown */
136 : __le32 next_cluster; /* Most recently allocated cluster */
137 : __le32 reserved2[4];
138 : };
139 1 :
140 : struct msdos_dir_entry {
141 : __u8 name[MSDOS_NAME];/* name and extension */
142 : __u8 attr; /* attribute bits */
143 : __u8 lcase; /* Case for base and extension */
144 : __u8 ctime_cs; /* Creation time, centiseconds (0-199) */
145 : __le16 ctime; /* Creation time */
146 : __le16 cdate; /* Creation date */
147 : __le16 adate; /* Last access date */
148 : __le16 starthi; /* High 16 bits of cluster in FAT32 */
149 : __le16 time,date,start;/* time, date and first cluster */
150 : __le32 size; /* file size (in bytes) */
151 : };
152 1 :
153 : /* Up to 13 characters of the name */
154 : struct msdos_dir_slot {
155 : __u8 id; /* sequence number for slot */
156 : __u8 name0_4[10]; /* first 5 characters in name */
157 : __u8 attr; /* attribute byte */
158 : __u8 reserved; /* always 0 */
159 : __u8 alias_checksum; /* checksum for 8.3 alias */
160 : __u8 name5_10[12]; /* 6 more characters in name */
161 : __le16 start; /* starting cluster number, 0 in long slots */
162 : __u8 name11_12[4]; /* last 2 characters in name */
163 : };
164 :
165 : #ifdef __KERNEL__
166 : /* media of boot sector */
167 : static inline int fat_valid_media(u8 media)
168 : {
169 0 : return 0xf8 <= media || media == 0xf0;
170 : }
171 1 : #endif /* !__KERNEL__ */
172 : #endif /* !_LINUX_MSDOS_FS_H */
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