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Date:   Thu, 30 Jan 2020 13:35:33 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Dave Chinner <david@fromorbit.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/12] fuse: Convert from readpages to readahead
Message-ID: <20200130213533.GN6615@bombadil.infradead.org>
References: <20200125013553.24899-1-willy@infradead.org>
 <20200125013553.24899-12-willy@infradead.org>
 <20200129010829.GK18610@dread.disaster.area>
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On Wed, Jan 29, 2020 at 12:08:29PM +1100, Dave Chinner wrote:
> On Fri, Jan 24, 2020 at 05:35:52PM -0800, Matthew Wilcox wrote:
> > +	while (nr_pages--) {
> > +		struct page *page = readahead_page(mapping, start++);
> > +		int err = fuse_readpages_fill(&data, page);
> > +
> > +		if (!err)
> > +			continue;
> > +		nr_pages++;
> > +		goto out;
> >  	}
> 
> That's some pretty convoluted logic. Perhaps:
> 
> 	for (; nr_pages > 0 ; nr_pages--) {
> 		struct page *page = readahead_page(mapping, start++);
> 
> 		if (fuse_readpages_fill(&data, page))
> 			goto out;
> 	}

I have a bit of an aversion to that style of for loop ... I like this
instead:

        while (nr_pages) {
                struct page *page = readahead_page(mapping, start++);

                if (fuse_readpages_fill(&data, page) != 0)
                        goto out;
                nr_pages--;
        }