From: Artem Bityutskiy Subject: Re: [PATCH v1 0/9] do not use s_dirt in ext4 Date: Thu, 22 Mar 2012 13:25:37 +0200 Message-ID: <1332415537.18717.21.camel@sauron.fi.intel.com> References: <1332254489-2300-1-git-send-email-dedekind1@gmail.com> <20120322095342.GC14485@quack.suse.cz> <1332410747.18717.12.camel@sauron.fi.intel.com> <20120322103309.GA14484@quack.suse.cz> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-m7BzqZp205qfFoP0txw4" Cc: Ted Tso , Ext4 Mailing List , Linux FS Maling List , Linux Kernel Maling List To: Jan Kara Return-path: Received: from mga02.intel.com ([134.134.136.20]:33815 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751526Ab2CVLXJ (ORCPT ); Thu, 22 Mar 2012 07:23:09 -0400 In-Reply-To: <20120322103309.GA14484@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: --=-m7BzqZp205qfFoP0txw4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2012-03-22 at 11:33 +0100, Jan Kara wrote: > > However, if there is _no_ journal, the 'write_super' is initialized, an= d > > in many places the 's_dirt' flag is set, and thus VFS services seem to > > be actively used. > Which many places are you speaking about? Grep shows 4 places with > sb->s_dirt =3D 1; Well, with 'ext4_mark_super_dirty()' there are still 6 or something places. > You remove two of those in your cleanups so only > __ext4_handle_dirty_super() remains. That is called from 3 (4 after your > cleanups) places and they happen so rarely (during filesystem resize or > when we start using some feature on the filesystem) that if you use > sync_buffer() from all of them, it should be fine. But AFAIKC, the whole '__ext4_handle_dirty_super()' also falls-back to marking the superblock as dirty if the file-system has no journal for some reasons, right?. But I do not really understand what 'ext4_handle_valid()' does. If I grep for 'ext4_handle_dirty_super()' - there are many places places where it is used, and a few are obviously for the superblocks. --=20 Best Regards, Artem Bityutskiy --=-m7BzqZp205qfFoP0txw4 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABAgAGBQJPawwxAAoJECmIfjd9wqK0LJEP/1KCA9fBdQvnZuoRMKsCCEom rFsuWStPynTbB95PruUj3C7tJs4H3NrqPIZTfZ9p5F2mULSd+VVhHaAEJz/xOEy4 4MLboIgRkJTtO73LbXW9x2UngP1yKohti3R9wYbHvMnwJFCgDA+HY54JHURd+6mG eJ2cWphuyZy6rTJbBkruXhvhb0qS/Iqmdp9aj2/tvf+23WSU9j41qejrqH7ZVxpg NiAtP4ErdzEfi9OBEEYHJkMvyuXZtBfeZatqKGGVnR0eA9WjGLWArAFCxXiZ7UXV EqYLKZjSIhA9m2RUWfM6IX9/ZEKyct3klXQPEvKwpDGJ1mZh23AQDWOEZC0b/HYo JH1r8GnZ2VXP7cgGh1xmjt78aH0nLGHaHrXZOA9eED+F22zB89EgbdLv0Kr3P0Tr Pye59QjhKH4n6ntJPlJWjLQx1XMSRnN7sToBxMu31HXH8ua8wc6pbTEOv6bRUSh8 Yd8nyystKXV6+JQkcbz836sNQSKG1moljCGfOCO3u6WqaktkkpjMSUy5BEaTVNFM fm0GMmMTgTvtYM+NDehtFpMAH6WMASTRZQR8SwU/qwF91kyvRsOjIowUzZblsF5j SOBRDo8/C8Y2YtJ27dKWQpjJ/cv35se438fMeuoYJ78s9/a+S0qVFIyVDg5RrzsO ujYHLJhzm3PBqifaGRN0 =FB1n -----END PGP SIGNATURE----- --=-m7BzqZp205qfFoP0txw4--