Re: [PATCH v2 2/4] mm: add file_fdatawait_range and file_write_and_wait

[Matthew Wilcox]

On Wed, Jul 26, 2017 at 01:55:36PM -0400, Jeff Layton wrote:
> +int file_write_and_wait(struct file *file)
> +{
> +	int err = 0, err2;
> +	struct address_space *mapping = file->f_mapping;
> +
> +	if ((!dax_mapping(mapping) && mapping->nrpages) ||
> +	    (dax_mapping(mapping) && mapping->nrexceptional)) {

Since patch 1 exists, shouldn't this use the new helper?

> +		err = filemap_fdatawrite(mapping);
> +		/* See comment of filemap_write_and_wait() */
> +		if (err != -EIO) {
> +			loff_t i_size = i_size_read(mapping->host);
> +
> +			if (i_size != 0)
> +				__filemap_fdatawait_range(mapping, 0,
> +							  i_size - 1);
> +		}
> +	}
> +	err2 = file_check_and_advance_wb_err(file);
> +	if (!err)
> +		err = err2;
> +	return err;

Would this be clearer written as:

	if (err)
		return err;
	return err2;

or even ...

	return err ? err : err2;