f2fs: use round_up to enhance calculation

.i_cluster_size should be power of 2, so we can use round_up() instead
of roundup() to enhance the calculation.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -742,16 +742,9 @@ int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock)
 	 * for compressed file, only support cluster size
 	 * aligned truncation.
 	 */
-	if (f2fs_compressed_file(inode)) {
-		size_t cluster_shift = PAGE_SHIFT +
-					F2FS_I(inode)->i_log_cluster_size;
-		size_t cluster_mask = (1 << cluster_shift) - 1;
-
-		free_from = from >> cluster_shift;
-		if (from & cluster_mask)
-			free_from++;
-		free_from <<= cluster_shift;
-	}
+	if (f2fs_compressed_file(inode))
+		free_from = round_up(from,
+				F2FS_I(inode)->i_cluster_size << PAGE_SHIFT);
 #endif
 
 	err = f2fs_do_truncate_blocks(inode, free_from, lock);
@@ -3563,7 +3556,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
 
 		end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
 		count = min(end_offset - dn.ofs_in_node, last_idx - page_idx);
-		count = roundup(count, F2FS_I(inode)->i_cluster_size);
+		count = round_up(count, F2FS_I(inode)->i_cluster_size);
 
 		ret = release_compress_blocks(&dn, count);
 
@@ -3715,7 +3708,7 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
 
 		end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
 		count = min(end_offset - dn.ofs_in_node, last_idx - page_idx);
-		count = roundup(count, F2FS_I(inode)->i_cluster_size);
+		count = round_up(count, F2FS_I(inode)->i_cluster_size);
 
 		ret = reserve_compress_blocks(&dn, count);