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From: Steve French <smfrench@gmail.com>
Date: Tue, 28 Aug 2018 13:32:39 -0500
Message-ID: <CAH2r5mudeZQ_QSKBGFuqsdS=BD7HLsq5dwprHSzso6O52aQdQA@mail.gmail.com>
Subject: Re: Streams support in Linux
To: Jeremy Allison <jra@samba.org>
Cc: Theodore Tso <tytso@mit.edu>, Matthew Wilcox <willy@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        ebiggers@kernel.org,
        samba-technical <samba-technical@lists.samba.org>
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On Tue, Aug 28, 2018 at 1:12 PM Jeremy Allison <jra@samba.org> wrote:
>
> On Mon, Aug 27, 2018 at 08:07:35PM -0500, Steve French wrote:
> >
> > Given that streams need to be read to backup Macs and Windows
> > (and for a few features of these servers mentioned earlier)
> > and would be exposed in ntfs (and SMB3 remotely) locally on Linux,
> > seems useful to me to have some consistent way to open and read
> > them on Linux even if we don't want to generalize it to other local fs.
> > The protocol supports it fine (just a file with a reserved character
> > ':' in it) but a little tricky to avoid name conflict with posix ':'
> > in filenames
>
> This sounds like a case for a couple of ioctls. One to enumerate
> the streams on an open fd, one to open a given stream name on an
> open fd.

We already have a (cifs.ko) ioctl to enumerate streams, but I was
less comfortable with how to structure an ioctl to read/write a
stream (other than $DATA of course).  Ideas on what a "read stream"
ioctl might look like?

-- 
Thanks,

Steve