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Date: Sat, 24 Sep 2016 04:59:08 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>, CAI Qian <caiqian@redhat.com>,
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Subject: Re: [PATCH 04/11] splice: lift pipe_lock out of splice_to_pipe()
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On Fri, Sep 23, 2016 at 01:36:12PM -0700, Linus Torvalds wrote:
> On Fri, Sep 23, 2016 at 1:10 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > OTOH, considering the quality of documentation, I'm somewhat tempted to go
> > for "sleep only if it had been completely full when we entered; once there's
> > some space feed as much as fits and be done with that".  OTTH, I'm not sure
> > that no userland cr^Hode will manage to be hurt by that variant...
> 
> Let's just try it.
> 
> If that then doesn't work, we can introduce your odd code (with a
> *big* comment). Ok?

	FWIW, updated (with fixes) and force-pushed.  Added piece:
default_file_splice_read() converted to iov_iter.  Seems to work, after
fixing a braino in __pipe_get_pages().  Changed: #4 (sleep only in the
beginning, as described above), #6 (context changes from #4), #10 (missing
get_page() added in __pipe_get_pages()), #11 (removed pointless truncation
of len - ->read_iter() can bloody well handle that on its own) and added #12.
Stands at 28 files changed, 657 insertions(+), 1009 deletions(-) now...