← Back
Editing: msdos_fs.h
/* 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 */ #define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \ MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x)) /* 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 #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \ MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12) /* 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[11]; /* 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[11]; /* 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 */
Save File
Cancel