From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] fuse: Add support for fuse stacked I/O Date: Fri, 15 Jan 2016 01:29:49 -0800 Message-ID: <20160115092949.GA11468@infradead.org> References: <565394BE.4040506@codeaurora.org> <5696E366.2080605@codeaurora.org> <20160114082554.GA12489@infradead.org> <87mvs8qhun.fsf@thinkpad.rath.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87mvs8qhun.fsf-Zv899e0YUSYPWKMTL/zdXNi2O/JbrIOy@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christoph Hellwig , Nikhilesh Reddy , Miklos Szeredi , fuse-devel , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, Richard Weinberger , Theodore Ts'o , jack-AlSwsSmVLrQ@public.gmane.org, Antonio SJ Musumeci , sven.utcke-Mmb7MZpHnFY@public.gmane.org List-Id: linux-api@vger.kernel.org On Thu, Jan 14, 2016 at 07:52:00AM -0800, Nikolaus Rath wrote: > > Please write your stacked features as kernel drivers. > > Could you explain in more detail? I think I don't understand either the > why, the how, or what you mean with driver in this context (not sure > which one it is). > > > (I'm not the original submitter but interested in this) If someone is doing stacked pass through I/O, which basically is some form of unioning or file hiding it should be using overlayfs or a new kernel stackable file system. That's not to say it could be prototyped entirely in userspace, but it's not something we should add any bypasses for.