Re: [PATCH v2 3/3] fat: New inline functions to determine the FAT variant (32, 16 or 12)

From: OGAWA Hirofumi
Date: Sat Dec 15 2018 - 14:11:25 EST


Carmeli Tamir <carmeli.tamir@xxxxxxxxx> writes:

> This patch introduces 3 new inline functions - IS_FAT12, IS_FAT16 and
> IS_FAT32, and replaces every occurrence in the code in which the FS
> variant (whether this is FAT12, FAT16 or FAT32) was previously checked
> using msdos_sb_info->fat_bits.

Could you use lower case chars for inline functions?

> Signed-off-by: Carmeli Tamir <carmeli.tamir@xxxxxxxxx>
> ---
> fs/fat/cache.c | 2 +-
> fs/fat/dir.c | 4 ++--
> fs/fat/fat.h | 25 ++++++++++++++++++++++---
> fs/fat/fatent.c | 16 +++++++---------
> fs/fat/inode.c | 12 ++++++------
> fs/fat/misc.c | 2 +-
> 6 files changed, 39 insertions(+), 22 deletions(-)
>
> diff --git a/fs/fat/cache.c b/fs/fat/cache.c
> index 78d501c..30c51b9 100644
> --- a/fs/fat/cache.c
> +++ b/fs/fat/cache.c
> @@ -363,7 +363,7 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
>
> *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;
> diff --git a/fs/fat/dir.c b/fs/fat/dir.c
> index c8366cb..b0b8f44 100644
> --- a/fs/fat/dir.c
> +++ b/fs/fat/dir.c
> @@ -57,7 +57,7 @@ static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
> 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);
> @@ -1313,7 +1313,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
> }
> }
> 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)",
> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
> index 11bc4a2..5b6f1c8 100644
> --- a/fs/fat/fat.h
> +++ b/fs/fat/fat.h
> @@ -142,13 +142,32 @@ 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 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)
> @@ -266,7 +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;
> }
> diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
> index f58c0ca..9166d96 100644
> --- a/fs/fat/fatent.c
> +++ b/fs/fat/fatent.c
> @@ -290,19 +290,17 @@ void fat_ent_access_init(struct super_block *sb)
>
> 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);
> }
> }
>
> @@ -310,7 +308,7 @@ static void mark_fsinfo_dirty(struct super_block *sb)
> {
> 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);
> @@ -327,7 +325,7 @@ static inline int fat_ent_update_ptr(struct super_block *sb,
> /* 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) {
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index 708de6d..a84b61b 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -686,7 +686,7 @@ static void fat_set_state(struct super_block *sb,
>
> 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
> @@ -1397,7 +1397,7 @@ static int fat_read_root(struct inode *inode)
> 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)
> @@ -1424,7 +1424,7 @@ static unsigned long calc_fat_clusters(struct super_block *sb)
> 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;
> }
> @@ -1744,7 +1744,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
> }
>
> /* 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;
> @@ -1770,11 +1770,11 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
>
> 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;
> diff --git a/fs/fat/misc.c b/fs/fat/misc.c
> index fce0a76..5368c6a 100644
> --- a/fs/fat/misc.c
> +++ b/fs/fat/misc.c
> @@ -64,7 +64,7 @@ int fat_clusters_flush(struct super_block *sb)
> 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);

--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>