[PATCH v2 1/9] exfat: replace unsafe macros with static inline functions

[Namjae Jeon <linkinjeon@kernel.org>]

The current exFAT driver relies on various macros for unit conversions
between clusters, blocks, sectors, and directory entries. These macros
are structurally unsafe as they lack type enforcement and are prone to
potential integer overflows during bit-shift operations, especially
on 64-bit architectures. Replace all arithmetic macros with static inline
functions to provide strict type checking and explicit casting.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
 fs/exfat/balloc.c   |   2 +-
 fs/exfat/dir.c      |  48 ++++++++---------
 fs/exfat/exfat_fs.h | 122 ++++++++++++++++++++++++++++++++------------
 fs/exfat/fatent.c   |   4 +-
 fs/exfat/file.c     |   8 +--
 fs/exfat/inode.c    |  19 +++----
 fs/exfat/namei.c    |  26 +++++-----
 fs/exfat/super.c    |   4 +-
 8 files changed, 147 insertions(+), 86 deletions(-)

diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
index 625f2f14d4fe..e66ebf899778 100644
--- a/fs/exfat/balloc.c
+++ b/fs/exfat/balloc.c
@@ -112,7 +112,7 @@ static int exfat_allocate_bitmap(struct super_block *sb,
 	}
 
 	if (exfat_test_bitmap_range(sb, sbi->map_clu,
-		EXFAT_B_TO_CLU_ROUND_UP(map_size, sbi)) == false)
+		exfat_bytes_to_cluster_round_up(sbi, map_size)) == false)
 		goto err_out;
 
 	return 0;
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index ac008ccaa97d..ca9d707220df 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -76,7 +76,7 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
-	unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
+	unsigned int dentry = exfat_bytes_to_dentries(*cpos) & 0xFFFFFFFF;
 	struct buffer_head *bh;
 
 	/* check if the given file ID is opened */
@@ -84,13 +84,13 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent
 		return -EPERM;
 
 	exfat_chain_set(&dir, ei->start_clu,
-		EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
+		exfat_bytes_to_cluster(sbi, i_size_read(inode)), ei->flags);
 
 	dentries_per_clu = sbi->dentries_per_clu;
-	max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES,
-				(u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi));
+	max_dentries = min(MAX_EXFAT_DENTRIES,
+			exfat_cluster_to_dentries(sbi, sbi->num_clusters));
 
-	clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi);
+	clu_offset = exfat_dentries_to_cluster(sbi, dentry);
 	exfat_chain_dup(&clu, &dir);
 
 	if (clu.flags == ALLOC_FAT_CHAIN) {
@@ -147,10 +147,10 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent
 			dir_entry->dir = clu;
 			brelse(bh);
 
-			ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi);
+			ei->hint_bmap.off = exfat_dentries_to_cluster(sbi, dentry);
 			ei->hint_bmap.clu = clu.dir;
 
-			*cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);
+			*cpos = exfat_dentries_to_bytes(dentry + 1 + num_ext);
 			return 0;
 		}
 
@@ -160,7 +160,7 @@ static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_ent
 
 out:
 	dir_entry->namebuf.lfn[0] = '\0';
-	*cpos = EXFAT_DEN_TO_B(dentry);
+	*cpos = exfat_dentries_to_bytes(dentry);
 	return 0;
 }
 
@@ -465,7 +465,7 @@ static void exfat_free_benign_secondary_clusters(struct inode *inode,
 		return;
 
 	exfat_chain_set(&dir, start_clu,
-			EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)),
+			exfat_bytes_to_cluster_round_up(EXFAT_SB(sb), size),
 			flags);
 	exfat_free_cluster(inode, &dir);
 }
@@ -556,10 +556,11 @@ static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir
 	unsigned int off, clu = 0;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 
-	off = EXFAT_DEN_TO_B(entry);
+	off = exfat_dentries_to_bytes(entry);
 
 	clu = p_dir->dir;
-	ret = exfat_cluster_walk(sb, &clu, EXFAT_B_TO_CLU(off, sbi), p_dir->flags);
+	ret = exfat_cluster_walk(sb, &clu, exfat_bytes_to_cluster(sbi, off),
+			p_dir->flags);
 	if (ret)
 		return ret;
 
@@ -567,7 +568,7 @@ static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir
 		exfat_fs_error(sb,
 			"unexpected early break in cluster chain (clu : %u, len : %d)",
 			p_dir->dir,
-			EXFAT_B_TO_CLU(off, sbi));
+			exfat_bytes_to_cluster(sbi, off));
 		return -EIO;
 	}
 
@@ -577,13 +578,13 @@ static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir
 	}
 
 	/* byte offset in cluster */
-	off = EXFAT_CLU_OFFSET(off, sbi);
+	off = exfat_cluster_offset(sbi, off);
 
 	/* byte offset in sector    */
-	*offset = EXFAT_BLK_OFFSET(off, sb);
+	*offset = exfat_block_offset(sb, off);
 
 	/* sector offset in cluster */
-	*sector = EXFAT_B_TO_BLK(off, sb);
+	*sector = exfat_bytes_to_block(sb, off);
 	*sector += exfat_cluster_to_sector(sbi, clu);
 	return 0;
 }
@@ -593,7 +594,7 @@ struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	unsigned int sect_per_clus = sbi->sect_per_clus;
-	unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
+	unsigned int dentries_per_page = exfat_bytes_to_dentries(PAGE_SIZE);
 	int off;
 	sector_t sec;
 
@@ -672,8 +673,8 @@ struct exfat_dentry *exfat_get_dentry_cached(
 	struct exfat_entry_set_cache *es, int num)
 {
 	int off = es->start_off + num * DENTRY_SIZE;
-	struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
-	char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
+	struct buffer_head *bh = es->bh[exfat_bytes_to_block(es->sb, off)];
+	char *p = bh->b_data + exfat_block_offset(es->sb, off);
 
 	return (struct exfat_dentry *)p;
 }
@@ -741,7 +742,7 @@ static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,
 
 	es->num_entries = num_entries;
 
-	num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
+	num_bh = exfat_bytes_to_block_round_up(sb, off + num_entries * DENTRY_SIZE);
 	if (num_bh > ARRAY_SIZE(es->__bh)) {
 		es->bh = kmalloc_objs(*es->bh, num_bh, GFP_NOFS);
 		if (!es->bh) {
@@ -830,7 +831,7 @@ static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es)
 
 err_used_follow_unused:
 	off = es->start_off + (i << DENTRY_SIZE_BITS);
-	bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
+	bh = es->bh[exfat_bytes_to_block(es->sb, off)];
 
 	exfat_fs_error(es->sb,
 		"in sector %lld, dentry %d should be unused, but 0x%x",
@@ -839,7 +840,8 @@ static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es)
 	return -EIO;
 
 count_skip_entries:
-	es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off);
+	es->num_entries =
+		exfat_bytes_to_dentries(exfat_block_to_bytes(es->sb, es->num_bh) - es->start_off);
 	for (; i < es->num_entries; i++) {
 		ep = exfat_get_dentry_cached(es, i);
 		if (IS_EXFAT_DELETED(ep->type))
@@ -892,7 +894,7 @@ static inline void exfat_set_empty_hint(struct exfat_inode_info *ei,
 {
 	if (ei->hint_femp.eidx == EXFAT_HINT_NONE ||
 	    ei->hint_femp.eidx > dentry) {
-		int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode));
+		int total_entries = exfat_bytes_to_dentries(i_size_read(&ei->vfs_inode));
 
 		if (candi_empty->count == 0) {
 			candi_empty->cur = *clu;
@@ -1215,7 +1217,7 @@ static int exfat_get_volume_label_dentry(struct super_block *sb,
 			es->bh = es->__bh;
 			es->bh[0] = bh;
 			es->num_bh = 1;
-			es->start_off = EXFAT_DEN_TO_B(i) % sb->s_blocksize;
+			es->start_off = exfat_dentries_to_bytes(i) % sb->s_blocksize;
 
 			return 0;
 		}
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 89ef5368277f..9c8ab3df7a42 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -84,38 +84,6 @@ enum {
 	(min_t(blkcnt_t, (sb)->s_bdi->ra_pages, (sb)->s_bdi->io_pages) \
 	<< (PAGE_SHIFT - (sb)->s_blocksize_bits))
 
-/*
- * helpers for cluster size to byte conversion.
- */
-#define EXFAT_CLU_TO_B(b, sbi)		((b) << (sbi)->cluster_size_bits)
-#define EXFAT_B_TO_CLU(b, sbi)		((b) >> (sbi)->cluster_size_bits)
-#define EXFAT_B_TO_CLU_ROUND_UP(b, sbi)	\
-	(((b - 1) >> (sbi)->cluster_size_bits) + 1)
-#define EXFAT_CLU_OFFSET(off, sbi)	((off) & ((sbi)->cluster_size - 1))
-
-/*
- * helpers for block size to byte conversion.
- */
-#define EXFAT_BLK_TO_B(b, sb)		((b) << (sb)->s_blocksize_bits)
-#define EXFAT_B_TO_BLK(b, sb)		((b) >> (sb)->s_blocksize_bits)
-#define EXFAT_B_TO_BLK_ROUND_UP(b, sb)	\
-	(((b - 1) >> (sb)->s_blocksize_bits) + 1)
-#define EXFAT_BLK_OFFSET(off, sb)	((off) & ((sb)->s_blocksize - 1))
-
-/*
- * helpers for block size to dentry size conversion.
- */
-#define EXFAT_B_TO_DEN(b)		((b) >> DENTRY_SIZE_BITS)
-#define EXFAT_DEN_TO_B(b)		((b) << DENTRY_SIZE_BITS)
-
-/*
- * helpers for cluster size to dentry size conversion.
- */
-#define EXFAT_CLU_TO_DEN(clu, sbi)	\
-	((clu) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
-#define EXFAT_DEN_TO_CLU(dentry, sbi)	\
-	((dentry) >> ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
-
 /*
  * helpers for fat entry.
  */
@@ -149,7 +117,7 @@ enum {
  * The 608 bytes are in 3 sectors at most (even 512 Byte sector).
  */
 #define DIR_CACHE_SIZE		\
-	(DIV_ROUND_UP(EXFAT_DEN_TO_B(ES_MAX_ENTRY_NUM), SECTOR_SIZE) + 1)
+	(DIV_ROUND_UP(ES_MAX_ENTRY_NUM << DENTRY_SIZE_BITS, SECTOR_SIZE) + 1)
 
 /* Superblock flags */
 #define EXFAT_FLAGS_SHUTDOWN	1
@@ -432,6 +400,94 @@ static inline loff_t exfat_ondisk_size(const struct inode *inode)
 	return ((loff_t)inode->i_blocks) << 9;
 }
 
+/*
+ * helpers for cluster size to byte conversion.
+ */
+static inline loff_t exfat_cluster_to_bytes(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return (loff_t)nr_clusters << sbi->cluster_size_bits;
+}
+
+static inline blkcnt_t exfat_cluster_to_sectors(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return (blkcnt_t)nr_clusters << (sbi->cluster_size_bits - 9);
+}
+
+static inline u32 exfat_bytes_to_cluster(struct exfat_sb_info *sbi, loff_t size)
+{
+	return (u32)(size >> sbi->cluster_size_bits);
+}
+
+static inline u32 exfat_bytes_to_cluster_round_up(struct exfat_sb_info *sbi,
+		loff_t size)
+{
+	if (size <= 0)
+		return 0;
+	return (u32)((size - 1) >> sbi->cluster_size_bits) + 1;
+}
+
+static inline u32 exfat_cluster_offset(struct exfat_sb_info *sbi, loff_t off)
+{
+	return off & (sbi->cluster_size - 1);
+}
+
+/*
+ * helpers for block size to byte conversion.
+ */
+static inline loff_t exfat_block_to_bytes(struct super_block *sb,
+		sector_t block)
+{
+	return (loff_t)block << sb->s_blocksize_bits;
+}
+
+static inline sector_t exfat_bytes_to_block(struct super_block *sb, loff_t size)
+{
+	return (sector_t)(size >> sb->s_blocksize_bits);
+}
+
+static inline sector_t exfat_bytes_to_block_round_up(struct super_block *sb,
+		loff_t size)
+{
+	if (size <= 0)
+		return 0;
+	return (sector_t)(((size - 1) >> sb->s_blocksize_bits) + 1);
+}
+
+static inline u32 exfat_block_offset(struct super_block *sb, loff_t off)
+{
+	return (u32)(off & (sb->s_blocksize - 1));
+}
+
+/*
+ * helpers for block size to dentry size conversion.
+ */
+static inline u32 exfat_bytes_to_dentries(loff_t b)
+{
+	return (u32)(b >> DENTRY_SIZE_BITS);
+}
+
+static inline u32 exfat_dentries_to_bytes(u32 dentry)
+{
+	return dentry << DENTRY_SIZE_BITS;
+}
+
+/*
+ * helpers for cluster size to dentry size conversion.
+ */
+static inline u32 exfat_cluster_to_dentries(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return nr_clusters << (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
+}
+
+static inline u32 exfat_dentries_to_cluster(struct exfat_sb_info *sbi,
+		u32 dentry)
+{
+	return dentry >> (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
+}
+
 /* super.c */
 int exfat_set_volume_dirty(struct super_block *sb);
 int exfat_clear_volume_dirty(struct super_block *sb);
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c
index dce0955e689a..45b0b754a2e4 100644
--- a/fs/exfat/fatent.c
+++ b/fs/exfat/fatent.c
@@ -412,8 +412,8 @@ int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
 
 	if (IS_DIRSYNC(dir))
 		return sync_blockdev_range(sb->s_bdev,
-				EXFAT_BLK_TO_B(blknr, sb),
-				EXFAT_BLK_TO_B(last_blknr, sb) - 1);
+				exfat_block_to_bytes(sb, blknr),
+				exfat_block_to_bytes(sb, last_blknr) - 1);
 
 	return 0;
 }
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 354bdcfe4abc..29a36a80e29b 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -33,9 +33,9 @@ static int exfat_cont_expand(struct inode *inode, loff_t size)
 	if (ret)
 		return ret;
 
-	num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
+	num_clusters = exfat_bytes_to_cluster(sbi, exfat_ondisk_size(inode));
 	/* integer overflow is already checked in inode_newsize_ok(). */
-	new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
+	new_num_clusters = exfat_bytes_to_cluster_round_up(sbi, size);
 
 	if (new_num_clusters == num_clusters)
 		goto out;
@@ -200,8 +200,8 @@ int __exfat_truncate(struct inode *inode)
 
 	exfat_set_volume_dirty(sb);
 
-	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
-	num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
+	num_clusters_new = exfat_bytes_to_cluster_round_up(sbi, i_size_read(inode));
+	num_clusters_phys = exfat_bytes_to_cluster(sbi, exfat_ondisk_size(inode));
 
 	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
 
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 1ea4c740fef9..d25e0a69865b 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -135,7 +135,7 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 	unsigned int local_clu_offset = clu_offset;
 	unsigned int num_to_be_allocated = 0, num_clusters;
 
-	num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
+	num_clusters = exfat_bytes_to_cluster(sbi, exfat_ondisk_size(inode));
 
 	if (clu_offset >= num_clusters)
 		num_to_be_allocated = clu_offset - num_clusters + 1;
@@ -216,7 +216,8 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
 
 		*clu = new_clu.dir;
 
-		inode->i_blocks += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9;
+		inode->i_blocks +=
+			exfat_cluster_to_sectors(sbi, num_to_be_allocated) >> 9;
 
 		/*
 		 * Move *clu pointer along FAT chains (hole care) because the
@@ -254,12 +255,12 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 
 	mutex_lock(&sbi->s_lock);
 	i_size = i_size_read(inode);
-	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size, sb);
+	last_block = exfat_bytes_to_block_round_up(sb, i_size);
 	if (iblock >= last_block && !create)
 		goto done;
 
 	/* Is this block already allocated? */
-	count = EXFAT_B_TO_CLU_ROUND_UP(bh_result->b_size, sbi);
+	count = exfat_bytes_to_cluster_round_up(sbi, bh_result->b_size);
 	err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,
 			&cluster, &count, create);
 	if (err) {
@@ -296,9 +297,9 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 	 * care the last nested block if valid_size is not equal to i_size.
 	 */
 	if (i_size == ei->valid_size || create || !bh_result->b_folio)
-		valid_blks = EXFAT_B_TO_BLK_ROUND_UP(ei->valid_size, sb);
+		valid_blks = exfat_bytes_to_block_round_up(sb, ei->valid_size);
 	else
-		valid_blks = EXFAT_B_TO_BLK(ei->valid_size, sb);
+		valid_blks = exfat_bytes_to_block(sb, ei->valid_size);
 
 	/* The range has been fully written, map it */
 	if (iblock + max_blocks < valid_blks)
@@ -313,7 +314,7 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 	/* The area has not been written, map and mark as new for create case */
 	if (create) {
 		set_buffer_new(bh_result);
-		ei->valid_size = EXFAT_BLK_TO_B(iblock + max_blocks, sb);
+		ei->valid_size = exfat_block_to_bytes(sb, iblock + max_blocks);
 		mark_inode_dirty(inode);
 		goto done;
 	}
@@ -343,7 +344,7 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 			goto done;
 		}
 
-		pos = EXFAT_BLK_TO_B(iblock, sb);
+		pos = exfat_block_to_bytes(sb, iblock);
 		size = ei->valid_size - pos;
 		addr = folio_address(bh_result->b_folio) +
 			offset_in_folio(bh_result->b_folio, pos);
@@ -374,7 +375,7 @@ static int exfat_get_block(struct inode *inode, sector_t iblock,
 	 */
 	clear_buffer_mapped(bh_result);
 done:
-	bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
+	bh_result->b_size = exfat_block_to_bytes(sb, max_blocks);
 	if (err < 0)
 		clear_buffer_mapped(bh_result);
 unlock_ret:
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 2c5636634b4a..752fbec9316b 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -208,7 +208,7 @@ static int exfat_search_empty_slot(struct super_block *sb,
 	int dentries_per_clu;
 	struct exfat_chain clu;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
-	int total_entries = EXFAT_CLU_TO_DEN(p_dir->size, sbi);
+	unsigned int total_entries = exfat_cluster_to_dentries(sbi, p_dir->size);
 
 	dentries_per_clu = sbi->dentries_per_clu;
 
@@ -266,7 +266,7 @@ static int exfat_search_empty_slot(struct super_block *sb,
 
 static int exfat_check_max_dentries(struct inode *inode)
 {
-	if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
+	if (exfat_bytes_to_dentries(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
 		/*
 		 * exFAT spec allows a dir to grow up to 8388608(256MB)
 		 * dentries
@@ -314,7 +314,8 @@ int exfat_find_empty_entry(struct inode *inode,
 	}
 
 	exfat_chain_set(p_dir, ei->start_clu,
-			EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
+			exfat_bytes_to_cluster(sbi, i_size_read(inode)),
+			ei->flags);
 
 	while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
 					num_entries, es)) < 0) {
@@ -375,7 +376,7 @@ int exfat_find_empty_entry(struct inode *inode,
 
 		hint_femp.cur.size++;
 		p_dir->size++;
-		size = EXFAT_CLU_TO_B(p_dir->size, sbi);
+		size = exfat_cluster_to_bytes(sbi, p_dir->size);
 
 		/* directory inode should be updated in here */
 		i_size_write(inode, size);
@@ -604,7 +605,7 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
 		return ret;
 
 	exfat_chain_set(&cdir, ei->start_clu,
-		EXFAT_B_TO_CLU(i_size_read(dir), sbi), ei->flags);
+		exfat_bytes_to_cluster(sbi, i_size_read(dir)), ei->flags);
 
 	/* check the validation of hint_stat and initialize it if required */
 	if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
@@ -681,7 +682,7 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
 		return -EIO;
 	}
 
-	if (unlikely(EXFAT_B_TO_CLU_ROUND_UP(info->size, sbi) > sbi->used_clusters)) {
+	if (unlikely(exfat_bytes_to_cluster_round_up(sbi, info->size) > sbi->used_clusters)) {
 		exfat_fs_error(sb, "data size is invalid(%lld)", info->size);
 		return -EIO;
 	}
@@ -695,7 +696,8 @@ static int exfat_find(struct inode *dir, const struct qstr *qname,
 
 	if (info->type == TYPE_DIR) {
 		exfat_chain_set(&cdir, info->start_clu,
-				EXFAT_B_TO_CLU(info->size, sbi), info->flags);
+				exfat_bytes_to_cluster(sbi, info->size),
+				info->flags);
 		count = exfat_count_dir_entries(sb, &cdir);
 		if (count < 0)
 			return -EIO;
@@ -951,7 +953,7 @@ static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 	}
 
 	exfat_chain_set(&clu_to_free, ei->start_clu,
-		EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
+		exfat_bytes_to_cluster_round_up(sbi, i_size_read(inode)), ei->flags);
 
 	err = exfat_check_dir_empty(sb, &clu_to_free);
 	if (err) {
@@ -1158,8 +1160,8 @@ static int __exfat_rename(struct inode *old_parent_inode,
 
 			new_clu.dir = new_ei->start_clu;
 			new_clu.size =
-				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
-				sbi);
+				exfat_bytes_to_cluster_round_up(sbi,
+						i_size_read(new_inode));
 			new_clu.flags = new_ei->flags;
 
 			ret = exfat_check_dir_empty(sb, &new_clu);
@@ -1203,8 +1205,8 @@ static int __exfat_rename(struct inode *old_parent_inode,
 			struct exfat_chain new_clu_to_free;
 
 			exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
-				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
-				sbi), new_ei->flags);
+				exfat_bytes_to_cluster_round_up(sbi, i_size_read(new_inode)),
+				new_ei->flags);
 
 			if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
 				/* just set I/O error only */
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 95d87e2d7717..cb2f8eefff99 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -369,7 +369,7 @@ static int exfat_read_root(struct inode *inode, struct exfat_chain *root_clu)
 	ei->hint_stat.clu = sbi->root_dir;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;
 
-	i_size_write(inode, EXFAT_CLU_TO_B(root_clu->size, sbi));
+	i_size_write(inode, exfat_cluster_to_bytes(sbi, root_clu->size));
 
 	num_subdirs = exfat_count_dir_entries(sb, root_clu);
 	if (num_subdirs < 0)
@@ -538,7 +538,7 @@ static int exfat_read_boot_sector(struct super_block *sb)
 	 * machines.
 	 */
 	sb->s_maxbytes = min(MAX_LFS_FILESIZE,
-			     EXFAT_CLU_TO_B((loff_t)EXFAT_MAX_NUM_CLUSTER, sbi));
+			     exfat_cluster_to_bytes(sbi, (loff_t)EXFAT_MAX_NUM_CLUSTER));
 
 	/* check logical sector size */
 	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
-- 
2.25.1