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From: Miklos Szeredi <miklos@szeredi.hu>
Date: Fri, 30 Sep 2016 09:30:21 +0200
Message-ID: <CAJfpegs9He0bWX3VWkr2EY-7X3-pAhNAUT=mQad-zxtWkQt_SQ@mail.gmail.com>
Subject: Re: [PATCH 10/12] new iov_iter flavour: pipe-backed
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To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Dave Chinner <david@fromorbit.com>, CAI Qian <caiqian@redhat.com>, linux-xfs <linux-xfs@vger.kernel.org>, xfs@oss.sgi.com, Jens Axboe <axboe@kernel.dk>, Nick Piggin <npiggin@gmail.com>, linux-fsdevel <linux-fsdevel@vger.kernel.org>

On Fri, Sep 30, 2016 at 12:50 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Thu, Sep 29, 2016 at 10:53:55PM +0200, Miklos Szeredi wrote:
>
>> The EFAULT logic seems to be missing across the board.  And callers
>> don't expect a zero return value.  Most will loop indefinitely.
>
> Nope.  copy_page_to_iter() *never* returns -EFAULT.  Including the iovec
> one - check copy_page_to_iter_iovec().  Any caller that does not expect
> a zero return value from that primitive is a bug, triggerable as soon as
> you feed it an iovec with NULL ->iov_base.

Right.

I was actually looking at iov_iter_get_pages() callers...

Thanks,
Miklos