From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965300AbcAUMii (ORCPT ); Thu, 21 Jan 2016 07:38:38 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:51923 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934891AbcAUMig (ORCPT ); Thu, 21 Jan 2016 07:38:36 -0500 X-Sasl-enc: jOtXhl0URp2U45gt1K429Cet6EczAhDbxnhp57AlBGYU 1453379915 Subject: Re: [PATCH v4] fuse: Add support for passthrough read/write To: Nikhilesh Reddy , torvalds@linux-foundation.org, Miklos Szeredi , fuse-devel , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, gregkh@linuxfoundation.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, Richard Weinberger , "Theodore Ts'o" , jack@suse.cz, Antonio SJ Musumeci , sven.utcke@gmx.de, Nikolaus Rath , Jann Horn References: <56A0235E.8090205@codeaurora.org> From: Bernd Schubert Message-ID: <56A0D148.7080508@fastmail.fm> Date: Thu, 21 Jan 2016 13:38:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <56A0235E.8090205@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/21/2016 01:16 AM, Nikhilesh Reddy wrote: > Add support for filesystem passthrough read/write of files > when enabled in userspace through the option FUSE_PASSTHROUGH. > > There are many FUSE based filesystems that perform checks or > enforce policy or perform some kind of decision making in certain > functions like the "open" call but simply act as a "passthrough" > when performing operations such as read or write. > > When FUSE_PASSTHROUGH is enabled all the reads and writes > to the fuse mount point go directly to the passthrough filesystem > i.e a native filesystem that actually hosts the files rather than > through the fuse daemon. All requests that aren't read/write still > go thought the userspace code. > > This allows for significantly better performance on read and writes. > The difference in performance between fuse and the native lower > filesystem is negligible. > > There is also a significant cpu/power savings that is achieved which > is really important on embedded systems that use fuse for I/O. > > Signed-off-by: Nikhilesh Reddy I think it is common style to add a change log between patch set versions in the patch description. Bernd