msdos_fs.h 6.7 KB

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