fat: Cleanup FAT attribute stuff

This adds three helpers:

fat_make_attrs() - makes FAT attributes from inode.
fat_make_mode()  - makes mode_t from FAT attributes.
fat_save_attrs() - saves FAT attributes to inode.

Then this replaces: MSDOS_MKMODE() by fat_make_mode(), fat_attr() by
fat_make_attrs(), ->i_attrs = attr & ATTR_UNUSED by fat_save_attrs().
And for root inode, those is used with ATTR_DIR instead of bogus
ATTR_NONE.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 1 deletions

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 2b8e94c..3b4753a 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -117,14 +117,32 @@ static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
 	return container_of(inode, struct msdos_inode_info, vfs_inode);
 }
 
+/* Convert attribute bits and a mask to the UNIX mode. */
+static inline mode_t fat_make_mode(struct msdos_sb_info *sbi,
+				   u8 attrs, mode_t mode)
+{
+	if (attrs & ATTR_RO)
+		mode &= ~S_IWUGO;
+
+	if (attrs & ATTR_DIR)
+		return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
+	else
+		return (mode & ~sbi->options.fs_fmask) | S_IFREG;
+}
+
 /* Return the FAT attribute byte for this inode */
-static inline u8 fat_attr(struct inode *inode)
+static inline u8 fat_make_attrs(struct inode *inode)
 {
 	return ((inode->i_mode & S_IWUGO) ? ATTR_NONE : ATTR_RO) |
 		(S_ISDIR(inode->i_mode) ? ATTR_DIR : ATTR_NONE) |
 		MSDOS_I(inode)->i_attrs;
 }
 
+static inline void fat_save_attrs(struct inode *inode, u8 attrs)
+{
+	MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
+}
+
 static inline unsigned char fat_checksum(const __u8 *name)
 {
 	unsigned char s = name[0];