From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 3B1267CA1 for ; Tue, 6 Sep 2016 14:15:50 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id AAA03AC007 for ; Tue, 6 Sep 2016 12:15:46 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com [156.151.31.81]) by cuda.sgi.com with ESMTP id MBmJjr8VkXHu66CD (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 06 Sep 2016 12:15:44 -0700 (PDT) Date: Tue, 6 Sep 2016 12:15:15 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 3/6] vfs: support FS_XFLAG_REFLINK and FS_XFLAG_COWEXTSIZE Message-ID: <20160906191515.GA26927@birch.djwong.org> References: <147216784041.525.7722906502172299465.stgit@birch.djwong.org> <147216786073.525.16014208838990530622.stgit@birch.djwong.org> <20160905145622.GB7662@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160905145622.GB7662@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: linux-api@vger.kernel.org, xfs@oss.sgi.com, linux-xfs@vger.kernel.org, viro@ZenIV.linux.org.uk, linux-fsdevel@vger.kernel.org On Mon, Sep 05, 2016 at 07:56:22AM -0700, Christoph Hellwig wrote: > On Thu, Aug 25, 2016 at 04:31:00PM -0700, Darrick J. Wong wrote: > > Introduce XFLAGs for the new XFS reflink inode flag and the CoW extent > > size hint, and actually plumb the CoW extent size hint into the fsxattr > > structure. > > Just curious, but why would we even bother to expose the reflink flag > to userspace? So far I've put the reflink flag to use in xfs_scrub to look for obvious signs of brokenness such as extents that overlap or have the shared flag set but the inode flag is off; and to skip various kinds of checks that don't have to happen when blocks don't overlap. I doubt there's much of a use for the flag outside of the XFS utilities. For a while I pondered only exposing the fsxattr flag if the caller had CAP_SYS_ADMIN (the level of priviledge required to run scrub) but decided that I wouldn't change the existing interface like that unless I had a really good reason. --D _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs