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From: Andy Lutomirski <luto@amacapital.net>
Date: Fri, 25 Sep 2015 17:14:59 -0700
Message-ID: <CALCETrWLAwNVqAiTMOmaktVY0cQkM0bX2vztXzEHm3EFYDg6zA@mail.gmail.com>
Subject: Re: [PATCH v3 8/9] vfs: copy_file_range() can do a pagecache copy
 with splice
To: Anna Schumaker <Anna.Schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org,
        Linux btrfs Developers List <linux-btrfs@vger.kernel.org>,
        Linux FS Devel <linux-fsdevel@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>, Zach Brown <zab@zabbo.net>,
        Al Viro <viro@zeniv.linux.org.uk>, Chris Mason <clm@fb.com>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Michael Kerrisk-manpages <mtk.manpages@gmail.com>, andros@netapp.com,
        Christoph Hellwig <hch@infradead.org>
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Sender: linux-nfs-owner@vger.kernel.org

On Fri, Sep 25, 2015 at 1:48 PM, Anna Schumaker
<Anna.Schumaker@netapp.com> wrote:
> The NFS server will need some kind offallback for filesystems that don't
> have any kind of copy acceleration, and it should be generally useful to
> have an in-kernel copy to avoid lots of switches between kernel and user
> space.
>
> I make this configurable by adding two new flags.  Users who only want a
> reflink can pass COPY_FR_REFLINK, and users who want a full data copy can
> pass COPY_FR_COPY.  The default (flags=0) means to first attempt a
> reflink, but use the pagecache if that fails.
>

Can you clarify how the subject line fits in?  I'm a bit lost.

--Andy