We will do the same check in generic_write_checks.
if (iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)
        return -EINVAL;
just remove the same check in f2fs_file_write_iter.
Signed-off-by: Lihong Kou <koulihong@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
                goto out;
        }
 
-       if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) {
-               ret = -EINVAL;
-               goto out;
-       }
-
        if (!inode_trylock(inode)) {
                if (iocb->ki_flags & IOCB_NOWAIT) {
                        ret = -EAGAIN;