From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH 2/6] f2fs: support goingdown for fs shutdown Date: Thu, 8 Jan 2015 13:21:29 -0800 Message-ID: <20150108211853.GB74570@jaegeuk-mac02> References: <1420740661-72288-1-git-send-email-jaegeuk@kernel.org> <1420740661-72288-2-git-send-email-jaegeuk@kernel.org> <54AEE06C.90806@sandeen.net> <20150108201843.GA74570@jaegeuk-mac02> <54AEE98D.5010103@sandeen.net> <20150108205416.GE25000@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric Sandeen , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net To: Dave Chinner Return-path: Received: from mail.kernel.org ([198.145.29.136]:38923 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754637AbbAHVVe (ORCPT ); Thu, 8 Jan 2015 16:21:34 -0500 Content-Disposition: inline In-Reply-To: <20150108205416.GE25000@dastard> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Jan 09, 2015 at 07:54:16AM +1100, Dave Chinner wrote: > On Thu, Jan 08, 2015 at 02:33:17PM -0600, Eric Sandeen wrote: > > On 1/8/15 2:18 PM, Jaegeuk Kim wrote: > > > On Thu, Jan 08, 2015 at 01:54:20PM -0600, Eric Sandeen wrote: > > >> On 1/8/15 12:10 PM, Jaegeuk Kim wrote: > > >>> This patch add an ioctl to shutdown f2fs, which stops all the further block > > >>> writes after this point. > > >> > > >> would it make sense to just re-use the xfs ioctl nr, if the semantics are > > >> the same? > > > > > > The semantics are not same for now. > > > In order to reuse xfs ioctl, it needs to support options for flushing logs. > > > > the xfs iotl has 3 behaviors optional: > > > > #define XFS_FSOP_GOING_FLAGS_DEFAULT 0x0 /* going down */ > > #define XFS_FSOP_GOING_FLAGS_LOGFLUSH 0x1 /* flush log but not data */ > > #define XFS_FSOP_GOING_FLAGS_NOLOGFLUSH 0x2 /* don't flush log nor data */ > > > > if f2fs currently supports a subset, you could just -EOPNOTSUPP on the others. > > No, just do a default shutdown operation if the semantics cannot be > supported. > > - XFS_FSOP_GOING_FLAGS_DEFAULT == > consistent on disk before shutdown > + implemented by freeze/thaw/shutdown sequence > - XFS_FSOP_GOING_FLAGS_LOGFLUSH == > consistent journal on disk before shutdown > + implemented by journal flush/shutdown sequence > - XFS_FSOP_GOING_FLAGS_NOLOGFLUSH == > nothing consistent on disk before shutdown > + just a shutdown call. > > f2fs can at least support XFS_FSOP_GOING_FLAGS_DEFAULT and > XFS_FSOP_GOING_FLAGS_NOLOGFLUSH.... > > > If the semantics are completely different, maybe it shouldn't share the > > name at all. ;) > > The semantics are quite clear and generic - when you look at what > they actually mean rather than looking at the implementation. > There's no need for new ioctls here. I'll check it out. Thank you, Dave and Eric. :) > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com