From: Matthew Wilcox <willy@infradead.org>
To: David Howells <dhowells@redhat.com>
Cc: 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
Date: Thu, 13 Sep 2018 09:43:51 -0700 [thread overview]
Message-ID: <20180913164351.GC11574@bombadil.infradead.org> (raw)
In-Reply-To: <17352.1536855503@warthog.procyon.org.uk>
On Thu, Sep 13, 2018 at 05:18:23PM +0100, David Howells wrote:
> 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?
At the time I did it, it was useful in dax, but I don't know if it is
any more. It might serve to replace iov_iter_zero().
next prev parent reply other threads:[~2018-09-13 16:43 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-13 15:51 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
2018-09-13 15:51 ` [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions David Howells
2018-09-13 15:51 ` [PATCH 02/10] iov_iter: Renumber the ITER_* constants in uio.h David Howells
2018-09-13 15:52 ` [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t David Howells
2018-09-13 15:52 ` [PATCH 04/10] iov_iter: Add mapping and discard iterator types David Howells
2018-09-14 4:18 ` Al Viro
2018-09-14 12:57 ` Trond Myklebust
2018-09-17 21:32 ` David Howells
2018-09-17 20:58 ` David Howells
2018-09-13 15:52 ` [PATCH 05/10] afs: Better tracing of protocol errors David Howells
2018-09-13 15:52 ` [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data() David Howells
2018-09-13 15:52 ` [PATCH 07/10] afs: Use ITER_MAPPING for writing David Howells
2018-09-13 15:52 ` [PATCH 08/10] afs: Add O_DIRECT read support David Howells
2018-09-13 15:52 ` [PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors David Howells
2018-09-13 15:52 ` [PATCH 10/10] afs: Don't invoke the server to read data beyond EOF David Howells
2018-09-13 16:10 ` [PATCH 00/10] iov_iter: Add new iters and use with AFS Matthew Wilcox
2018-09-13 16:18 ` David Howells
2018-09-13 16:43 ` Matthew Wilcox [this message]
2018-09-13 17:05 ` David Howells
2018-09-13 17:58 ` Al Viro
-- strict thread matches above, loose matches on Subject: below --
2018-08-06 13:16 David Howells
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