diff --git a/block/fops.c b/block/fops.c
index 9d6d86ebefb9..020443078630 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -402,6 +402,7 @@ static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 	iomap->addr = iomap->offset;
 	iomap->length = isize - iomap->offset;
 	iomap->flags |= IOMAP_F_BUFFER_HEAD; /* noop for !CONFIG_BUFFER_HEAD */
+	iomap->io_block_size = i_blocksize(inode);
 	return 0;
 }
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 753db965f7c0..665811b1578b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7740,6 +7740,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
 	iomap->offset = start;
 	iomap->bdev = fs_info->fs_devices->latest_dev->bdev;
 	iomap->length = len;
+	iomap->io_block_size = i_blocksize(inode);
 	free_extent_map(em);
 
 	return 0;
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 8be60797ea2f..ea9d2f3eadb3 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -305,6 +305,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		if (flags & IOMAP_DAX)
 			iomap->addr += mdev.m_dax_part_off;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 	return 0;
 }
 
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 9b248ee5fef2..6ee89f6a078c 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -749,6 +749,7 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
 		if (iomap->offset >= inode->i_size)
 			iomap->length = length + offset - map.m_la;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 	iomap->flags = 0;
 	return 0;
 }
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 0caa1650cee8..7a5539a52844 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -862,6 +862,7 @@ static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		iomap->length = (u64)ret << blkbits;
 		iomap->flags |= IOMAP_F_MERGED;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 
 	if (new)
 		iomap->flags |= IOMAP_F_NEW;
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e067f2dd0335..ce3269874fde 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4933,6 +4933,7 @@ static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
 	iomap->length = length;
 	iomap->type = iomap_type;
 	iomap->flags = 0;
+	iomap->io_block_size = i_blocksize(inode);
 out:
 	return error;
 }
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4bae9ccf5fe0..3ec82e4d71c4 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3235,6 +3235,7 @@ static void ext4_set_iomap(struct inode *inode, struct iomap *iomap,
 		iomap->bdev = inode->i_sb->s_bdev;
 	iomap->offset = (u64) map->m_lblk << blkbits;
 	iomap->length = (u64) map->m_len << blkbits;
+	iomap->io_block_size = i_blocksize(inode);
 
 	if ((map->m_flags & EXT4_MAP_MAPPED) &&
 	    !ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b9b0debc6b3d..6c12641b9a7b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -4233,6 +4233,7 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		}
 		iomap->addr = IOMAP_NULL_ADDR;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 
 	if (map.m_flags & F2FS_MAP_NEW)
 		iomap->flags |= IOMAP_F_NEW;
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index 12ef91d170bb..68ddc74cb31e 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -577,6 +577,7 @@ static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
 	iomap->flags = 0;
 	iomap->bdev = NULL;
 	iomap->dax_dev = fc->dax->dev;
+	iomap->io_block_size = i_blocksize(inode);
 
 	/*
 	 * Both read/write and mmap path can race here. So we need something
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1795c4e8dbf6..8d2de42b1da9 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -927,6 +927,7 @@ static int __gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
 
 out:
 	iomap->bdev = inode->i_sb->s_bdev;
+	iomap->io_block_size = i_blocksize(inode);
 unlock:
 	up_read(&ip->i_rw_mutex);
 	return ret;
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 1bb8d97cd9ae..5d2718faf520 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -149,6 +149,7 @@ static int hpfs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		iomap->addr = IOMAP_NULL_ADDR;
 		iomap->length = 1 << blkbits;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 
 	hpfs_unlock(sb);
 	return 0;
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index f3b43d223a46..5be8d886ab4a 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -277,7 +277,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 {
 	const struct iomap *iomap = &iter->iomap;
 	struct inode *inode = iter->inode;
-	unsigned int fs_block_size = i_blocksize(inode), pad;
+	u64 io_block_size = iomap->io_block_size;
 	loff_t length = iomap_length(iter);
 	loff_t pos = iter->pos;
 	blk_opf_t bio_opf;
@@ -287,6 +287,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 	int nr_pages, ret = 0;
 	size_t copied = 0;
 	size_t orig_count;
+	unsigned int pad;
 
 	if ((pos | length) & (bdev_logical_block_size(iomap->bdev) - 1) ||
 	    !bdev_iter_is_aligned(iomap->bdev, dio->submit.iter))
@@ -355,7 +356,14 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 
 	if (need_zeroout) {
 		/* zero out from the start of the block to the write offset */
-		pad = pos & (fs_block_size - 1);
+		if (is_power_of_2(io_block_size)) {
+			pad = pos & (io_block_size - 1);
+		} else {
+			loff_t _pos = pos;
+
+			pad = do_div(_pos, io_block_size);
+		}
+
 		if (pad)
 			iomap_dio_zero(iter, dio, pos - pad, pad);
 	}
@@ -429,9 +437,16 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 	if (need_zeroout ||
 	    ((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) {
 		/* zero out from the end of the write to the end of the block */
-		pad = pos & (fs_block_size - 1);
+		if (is_power_of_2(io_block_size)) {
+			pad = pos & (io_block_size - 1);
+		} else {
+			loff_t _pos = pos;
+
+			pad = do_div(_pos, io_block_size);
+		}
+
 		if (pad)
-			iomap_dio_zero(iter, dio, pos, fs_block_size - pad);
+			iomap_dio_zero(iter, dio, pos, io_block_size - pad);
 	}
 out:
 	/* Undo iter limitation to current extent */
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 378342673925..ecb4cae88248 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -127,6 +127,7 @@ xfs_bmbt_to_iomap(
 	}
 	iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff);
 	iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
+	iomap->io_block_size = i_blocksize(VFS_I(ip));
 	if (mapping_flags & IOMAP_DAX)
 		iomap->dax_dev = target->bt_daxdev;
 	else
diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c
index 3b103715acc9..bf2cc4bee309 100644
--- a/fs/zonefs/file.c
+++ b/fs/zonefs/file.c
@@ -50,6 +50,7 @@ static int zonefs_read_iomap_begin(struct inode *inode, loff_t offset,
 		iomap->addr = (z->z_sector << SECTOR_SHIFT) + iomap->offset;
 		iomap->length = isize - iomap->offset;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 	mutex_unlock(&zi->i_truncate_mutex);
 
 	trace_zonefs_iomap_begin(inode, iomap);
@@ -99,6 +100,7 @@ static int zonefs_write_iomap_begin(struct inode *inode, loff_t offset,
 		iomap->type = IOMAP_MAPPED;
 		iomap->length = isize - iomap->offset;
 	}
+	iomap->io_block_size = i_blocksize(inode);
 	mutex_unlock(&zi->i_truncate_mutex);
 
 	trace_zonefs_iomap_begin(inode, iomap);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6fc1c858013d..d63a35b77907 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -103,6 +103,8 @@ struct iomap {
 	void			*private; /* filesystem private */
 	const struct iomap_folio_ops *folio_ops;
 	u64			validity_cookie; /* used with .iomap_valid() */
+	/* io block zeroing size, not necessarily a power-of-2  */
+	u64			io_block_size;
 };
 
 static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos)
