From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhi Yong Wu Subject: Re: [RFC v2 03/10] vfs: add one new mount option '-o hottrack' Date: Thu, 27 Sep 2012 13:25:34 +0800 Message-ID: References: <1348404995-14372-1-git-send-email-zwu.kernel@gmail.com> <1348404995-14372-4-git-send-email-zwu.kernel@gmail.com> <20120925092819.GC29154@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 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 To: Dave Chinner Return-path: In-Reply-To: <20120925092819.GC29154@dastard> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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? > to check whether we are tracking hot inodes or not. > > This then means the hot inode tracking for the superblock can be > initialised by the filesystem as part of it's fill_super method, > along with the filesystem specific code that will use the hot > tracking information the VFS gathers.... > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com -- Regards, Zhi Yong Wu