diff options
Diffstat (limited to 'fs/fat/fat.h')
| -rw-r--r-- | fs/fat/fat.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 3b4753a024e3..313b645b8126 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -117,6 +117,25 @@ static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) return container_of(inode, struct msdos_inode_info, vfs_inode); } +/* + * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to + * save ATTR_RO instead of ->i_mode. + */ +static inline int fat_mode_can_hold_ro(struct inode *inode) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + mode_t mask; + + if (S_ISDIR(inode->i_mode)) + mask = ~sbi->options.fs_dmask; + else + mask = ~sbi->options.fs_fmask; + + if (!(mask & S_IWUGO)) + return 0; + return 1; +} + /* 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) @@ -133,14 +152,20 @@ static inline mode_t fat_make_mode(struct msdos_sb_info *sbi, /* Return the FAT attribute byte for this 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; + u8 attrs = MSDOS_I(inode)->i_attrs; + if (S_ISDIR(inode->i_mode)) + attrs |= ATTR_DIR; + if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) + attrs |= ATTR_RO; + return attrs; } static inline void fat_save_attrs(struct inode *inode, u8 attrs) { - MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; + if (fat_mode_can_hold_ro(inode)) + MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; + else + MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); } static inline unsigned char fat_checksum(const __u8 *name) |