diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 62f23f82b971..0ebf08f00b8f 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1458,8 +1458,12 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
 		new_size = ((loff_t)pg_end << PAGE_SHIFT) + off_end;
 	}
 
-	if (!(mode & FALLOC_FL_KEEP_SIZE) && i_size_read(inode) < new_size)
-		f2fs_i_size_write(inode, new_size);
+	if (new_size > i_size_read(inode)) {
+		if (mode & FALLOC_FL_KEEP_SIZE)
+			file_set_keep_isize(inode);
+		else
+			f2fs_i_size_write(inode, new_size);
+	}
 
 	return err;
 }
@@ -1506,8 +1510,6 @@ static long f2fs_fallocate(struct file *file, int mode,
 	if (!ret) {
 		inode->i_mtime = inode->i_ctime = current_time(inode);
 		f2fs_mark_inode_dirty_sync(inode, false);
-		if (mode & FALLOC_FL_KEEP_SIZE)
-			file_set_keep_isize(inode);
 		f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	}