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Date: Thu, 10 May 2018 08:44:09 +0200
From: Christoph Hellwig <hch@lst.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>, linux-xfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH 11/33] iomap: add an iomap-based readpage and readpages
        implementation
Message-ID: <20180510064409.GE11422@lst.de>
References: <20180509074830.16196-1-hch@lst.de> <20180509074830.16196-12-hch@lst.de> <20180510011758.GR10363@dastard>
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On Thu, May 10, 2018 at 11:17:58AM +1000, Dave Chinner wrote:
> > +		if (ret <= 0)
> > +			break;
> > +		pos += ret;
> > +		length -= ret;
> > +	}
> > +
> > +	ret = 0;
> 
> This means the function will always return zero, regardless of
> whether iomap_apply returned an error or not.
> 
> > +	if (ctx.bio)
> > +		submit_bio(ctx.bio);
> > +	if (ctx.cur_page) {
> > +		if (!ctx.cur_page_in_bio)
> > +			unlock_page(ctx.cur_page);
> > +		put_page(ctx.cur_page);
> > +	}
> > +	WARN_ON_ONCE(ret && !list_empty(ctx.pages));
> 
> And this warning will never trigger. Was this intended behaviour?
> If it is, it needs a comment, because it looks wrong....

Yes, the break should have been a goto out which jumps after the
ret.