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From:   David Howells <dhowells@redhat.com>
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To:     Matthew Wilcox <willy@infradead.org>
Cc:     dhowells@redhat.com, viro@zeniv.linux.org.uk,
        linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/10] iov_iter: Add new iters and use with AFS
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Date:   Thu, 13 Sep 2018 17:18:23 +0100
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Matthew Wilcox <willy@infradead.org> wrote:

> >  (5) Add an ITER_DISCARD iterator type.  This provides an iterator that
> >      simply discards anything written to it.  It cannot be used as a data
> >      source.
> 
> May I suggest an ITER_ZERO iterator type instead?  It acts like /dev/zero;
> writes are discarded (as you have here) and reads return zeroes.
> I've wanted such a thing in the past, but got distracted away from
> that project.

I thought about that, but the zero-filling is not as easy to implement as the
discard side - plus I don't have any use case to test it with.

Do you have a use case in mind?

David