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 <david@xxxxxxxxxxxxx> wrote: > > On Sun, Sep 23, 2012 at 08:56:28PM +0800, zwu.kernel@xxxxxxxxx wrote: > >> From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx> > >> > >> 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... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
