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-rw-r--r--fs/fat/fat.h30
1 files changed, 29 insertions, 1 deletions
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 4e1b2f6df5e6..922a0c6ba46c 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -142,6 +142,34 @@ static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
return sb->s_fs_info;
}
+/*
+ * Functions that determine the variant of the FAT file system (i.e.,
+ * whether this is FAT12, FAT16 or FAT32.
+ */
+static inline bool is_fat12(const struct msdos_sb_info *sbi)
+{
+ return sbi->fat_bits == 12;
+}
+
+static inline bool is_fat16(const struct msdos_sb_info *sbi)
+{
+ return sbi->fat_bits == 16;
+}
+
+static inline bool is_fat32(const struct msdos_sb_info *sbi)
+{
+ return sbi->fat_bits == 32;
+}
+
+/* Maximum number of clusters */
+static inline u32 max_fat(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ return is_fat32(sbi) ? MAX_FAT32 :
+ is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;
+}
+
static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
{
return container_of(inode, struct msdos_inode_info, vfs_inode);
@@ -257,7 +285,7 @@ static inline int fat_get_start(const struct msdos_sb_info *sbi,
const struct msdos_dir_entry *de)
{
int cluster = le16_to_cpu(de->start);
- if (sbi->fat_bits == 32)
+ if (is_fat32(sbi))
cluster |= (le16_to_cpu(de->starthi) << 16);
return cluster;
}