From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756707Ab2I0HVP (ORCPT ); Thu, 27 Sep 2012 03:21:15 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:62038 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755961Ab2I0HVN (ORCPT ); Thu, 27 Sep 2012 03:21:13 -0400 MIME-Version: 1.0 In-Reply-To: <20120927070508.GS15236@dastard> References: <1348404995-14372-1-git-send-email-zwu.kernel@gmail.com> <1348404995-14372-4-git-send-email-zwu.kernel@gmail.com> <20120925092819.GC29154@dastard> <20120927070508.GS15236@dastard> Date: Thu, 27 Sep 2012 15:21:11 +0800 Message-ID: Subject: Re: [RFC v2 03/10] vfs: add one new mount option '-o hottrack' From: Zhi Yong Wu To: Dave Chinner Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, cmm@us.ibm.com, tytso@mit.edu, marco.stornelli@gmail.com, stroetmann@ontolinux.com, diegocg@gmail.com, chris@csamuel.org, Zhi Yong Wu Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2012 at 3:05 PM, Dave Chinner wrote: > On Thu, Sep 27, 2012 at 01:25:34PM +0800, Zhi Yong Wu wrote: >> On Tue, Sep 25, 2012 at 5:28 PM, Dave Chinner wrote: >> > On Sun, Sep 23, 2012 at 08:56:28PM +0800, zwu.kernel@gmail.com wrote: >> >> From: Zhi Yong Wu >> >> >> >> Introduce one new mount option '-o hottrack', >> >> and add its parsing support. >> >> Its usage looks like: >> >> mount -o hottrack >> >> mount -o nouser,hottrack >> >> mount -o nouser,hottrack,loop >> >> mount -o hottrack,nouser >> > >> > I think that this option parsing should be done by the filesystem, >> > even though the tracking functionality is in the VFS. That way ony >> > the filesystems that can use the tracking information will turn it >> > on, rather than being able to turn it on for everything regardless >> > of whether it is useful or not. >> > >> > Along those lines, just using a normal superblock flag to indicate >> > it is active (e.g. MS_HOT_INODE_TRACKING in sb->s_flags) means you >> > don't need to allocate the sb->s_hot_info structure just to be able >> If we don't allocate one sb->s_hot_info, where will those hash list >> head and btree roots locate? > > I wrote that thinking (mistakenly) that s-hot)info was dynamically > allocated rather than being embedded in the struct super_block. > > Indeed, if the mount option is held in s_flags, then it could be > dynamically allocated, but I don't think that's really necessary... ah, you prefer allocating it, OK, let me try. thanks for your explaination. > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com -- Regards, Zhi Yong Wu