From 6b46419b0462ae565880f02e9cd0baf9b25ea71f Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Wed, 27 Feb 2013 17:03:07 -0800 Subject: fat: add extended fileds to struct fat_boot_sector Later we will need "state" field to check if volume was cleanly unmounted. Signed-off-by: Oleksij Rempel Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/uapi/linux/msdos_fs.h | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) (limited to 'include/uapi/linux/msdos_fs.h') diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h index 996719f82e28..b9f12450efe8 100644 --- a/include/uapi/linux/msdos_fs.h +++ b/include/uapi/linux/msdos_fs.h @@ -120,14 +120,34 @@ struct fat_boot_sector { __le32 hidden; /* hidden sectors (unused) */ __le32 total_sect; /* number of sectors (if sectors == 0) */ - /* The following fields are only used by FAT32 */ - __le32 fat32_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 */ + union { + struct { + /* Extended BPB Fields for FAT16 */ + __u8 drive_number; /* Physical drive number */ + __u8 state; /* undocumented, but used + for mount state. */ + /* other fiealds 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. */ + /* other fiealds are not added here */ + } fat32; + }; }; struct fat_boot_fsinfo { -- cgit v1.2.2 From b88a105802e9aeb6e234e8106659f5d1271081bb Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Wed, 27 Feb 2013 17:03:09 -0800 Subject: fat: mark fs as dirty on mount and clean on umount There is no documented methods to mark FAT as dirty. Unofficially MS started to use reserved Byte in boot sector for this purpose, at least since Win 2000. With Win 7 user is warned if fs is dirty and asked to clean it. Different versions of Win, handle it in different ways, but always have same meaning: - Win 2000 and XP, set it on write operations and remove it after operation was finnished - Win 7, set dirty flag on first write and remove it on umount. We will do it as follows: - set dirty flag on mount. If fs was initially dirty, warn user, remember it and do not do any changes to boot sector. - clean it on umount. If fs was initially dirty, leave it dirty. - do not do any thing if fs mounted read-only. - TODO: leave fs dirty if we found some error after mount. Signed-off-by: Oleksij Rempel Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/uapi/linux/msdos_fs.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi/linux/msdos_fs.h') diff --git a/include/uapi/linux/msdos_fs.h b/include/uapi/linux/msdos_fs.h index b9f12450efe8..f055e58b3147 100644 --- a/include/uapi/linux/msdos_fs.h +++ b/include/uapi/linux/msdos_fs.h @@ -87,6 +87,8 @@ #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; -- cgit v1.2.2