From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernd Schubert Subject: Re: [PATCH v4] fuse: Add support for passthrough read/write Date: Thu, 21 Jan 2016 13:38:32 +0100 Message-ID: <56A0D148.7080508@fastmail.fm> References: <56A0235E.8090205@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56A0235E.8090205-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Nikhilesh Reddy , torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, Miklos Szeredi , fuse-devel , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@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, Nikolaus Rath , Jann Horn List-Id: linux-api@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