*phys = 0;
*mapped_blocks = 0;
- if ((sbi->fat_bits != 32) && (inode->i_ino == MSDOS_ROOT_INO)) {
+ if (!is_fat32(sbi) && (inode->i_ino == MSDOS_ROOT_INO)) {
if (sector < (sbi->dir_entries >> sbi->dir_per_block_bits)) {
*phys = sector + sbi->dir_start;
*mapped_blocks = 1;
if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
return;
/* root dir of FAT12/FAT16 */
- if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
+ if (!is_fat32(sbi) && (dir->i_ino == MSDOS_ROOT_INO))
return;
bh = sb_find_get_block(sb, phys);
}
}
if (dir->i_ino == MSDOS_ROOT_INO) {
- if (sbi->fat_bits != 32)
+ if (!is_fat32(sbi))
goto error;
} else if (MSDOS_I(dir)->i_start == 0) {
fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
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 sbi->fat_bits == 32 ? MAX_FAT32 :
- sbi->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12;
+ return is_fat32(sbi) ? MAX_FAT32 :
+ is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;
}
static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
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;
}
mutex_init(&sbi->fat_lock);
- switch (sbi->fat_bits) {
- case 32:
+ if (is_fat32(sbi)) {
sbi->fatent_shift = 2;
sbi->fatent_ops = &fat32_ops;
- break;
- case 16:
+ } else if (is_fat16(sbi)) {
sbi->fatent_shift = 1;
sbi->fatent_ops = &fat16_ops;
- break;
- case 12:
+ } else if (is_fat12(sbi)) {
sbi->fatent_shift = -1;
sbi->fatent_ops = &fat12_ops;
- break;
+ } else {
+ fat_fs_error(sb, "invalid FAT variant, %u bits", sbi->fat_bits);
}
}
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
- if (sb_rdonly(sb) || sbi->fat_bits != 32)
+ if (sb_rdonly(sb) || !is_fat32(sbi))
return;
__mark_inode_dirty(sbi->fsinfo_inode, I_DIRTY_SYNC);
/* Is this fatent's blocks including this entry? */
if (!fatent->nr_bhs || bhs[0]->b_blocknr != blocknr)
return 0;
- if (sbi->fat_bits == 12) {
+ if (is_fat12(sbi)) {
if ((offset + 1) < sb->s_blocksize) {
/* This entry is on bhs[0]. */
if (fatent->nr_bhs == 2) {
b = (struct fat_boot_sector *) bh->b_data;
- if (sbi->fat_bits == 32) {
+ if (is_fat32(sbi)) {
if (set)
b->fat32.state |= FAT_STATE_DIRTY;
else
inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
inode->i_op = sbi->dir_ops;
inode->i_fop = &fat_dir_operations;
- if (sbi->fat_bits == 32) {
+ if (is_fat32(sbi)) {
MSDOS_I(inode)->i_start = sbi->root_cluster;
error = fat_calc_dir_size(inode);
if (error < 0)
struct msdos_sb_info *sbi = MSDOS_SB(sb);
/* Divide first to avoid overflow */
- if (sbi->fat_bits != 12) {
+ if (!is_fat12(sbi)) {
unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
return ent_per_sec * sbi->fat_length;
}
}
/* interpret volume ID as a little endian 32 bit integer */
- if (sbi->fat_bits == 32)
+ if (is_fat32(sbi))
sbi->vol_id = bpb.fat32_vol_id;
else /* fat 16 or 12 */
sbi->vol_id = bpb.fat16_vol_id;
total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
- if (sbi->fat_bits != 32)
+ if (!is_fat32(sbi))
sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
/* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
- if (sbi->fat_bits == 32)
+ if (is_fat32(sbi))
sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
else /* fat 16 or 12 */
sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
struct buffer_head *bh;
struct fat_boot_fsinfo *fsinfo;
- if (sbi->fat_bits != 32)
+ if (!is_fat32(sbi))
return 0;
bh = sb_bread(sb, sbi->fsinfo_sector);