From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754593AbaIPD7u (ORCPT ); Mon, 15 Sep 2014 23:59:50 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:57125 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753917AbaIPD7t (ORCPT ); Mon, 15 Sep 2014 23:59:49 -0400 X-IronPort-AV: E=Sophos;i="5.04,533,1406563200"; d="scan'208";a="36005062" Message-ID: <5417B283.10702@cn.fujitsu.com> Date: Tue, 16 Sep 2014 11:46:11 +0800 From: Gu Zheng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: Chao Yu CC: "'Jaegeuk Kim'" , "'Changman Lee'" , , Subject: Re: [f2fs-dev][PATCH 4/5] f2fs: fix to clean previous mount option when remount_fs References: <003001cfd0cc$96f9e8e0$c4edbaa0$@samsung.com> <54179768.2010708@cn.fujitsu.com> <00a001cfd15b$30bdadc0$92390940$@samsung.com> In-Reply-To: <00a001cfd15b$30bdadc0$92390940$@samsung.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.100] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/16/2014 11:05 AM, Chao Yu wrote: > Hi Gu, > >> -----Original Message----- >> From: Gu Zheng [mailto:guz.fnst@cn.fujitsu.com] >> Sent: Tuesday, September 16, 2014 9:51 AM >> To: Chao Yu >> Cc: Jaegeuk Kim; Changman Lee; linux-f2fs-devel@lists.sourceforge.net; >> linux-kernel@vger.kernel.org >> Subject: Re: [f2fs-dev][PATCH 4/5] f2fs: fix to clean previous mount option when remount_fs >> >> Hi Yu, >> On 09/15/2014 06:04 PM, Chao Yu wrote: >> >>> In manual of mount, we descript remount as below: >>> >>> "mount -o remount,rw /dev/foo /dir >>> After this call all old mount options are replaced and arbitrary stuff from >>> fstab is ignored, except the loop= option which is internally generated and >>> maintained by the mount command." >>> >>> Previously f2fs do not clear up old mount options when remount_fs, so we have no >>> chance of disabling previous option (e.g. flush_merge). Fix it. >> >> Please don't. >> "Remount" should just change what you specified and keep others unchanged. > > Actually, there are two kinds of different 'remount', they are all specified in > manual of mount. > 1) mount -o remount,rw /dev/foo /dir > 2) mount -o remount,rw /dir Thanks for your reminder, I confused them. Regards, Gu > > I think 'remount' in your description is the second kind, being different from the > first kind in description of this patch, for the second kind remount, 'mount' command > can keep old options by loading them from mtab/fstab then merge them with new > specified options. > > Thanks, > Yu > >> The problem here is that we need to provide mount opts for disable/enable >> some features, but we missed it. So the right way is adding these opts if >> we really need them. >> >> Thanks, >> Gu >> >>> >>> Signed-off-by: Chao Yu >>> --- >>> fs/f2fs/super.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c >>> index 54444bb..90fcbe0 100644 >>> --- a/fs/f2fs/super.c >>> +++ b/fs/f2fs/super.c >>> @@ -616,6 +616,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data) >>> org_mount_opt = sbi->mount_opt; >>> active_logs = sbi->active_logs; >>> >>> + sbi->mount_opt.opt = 0; >>> + sbi->active_logs = NR_CURSEG_TYPE; >>> + >>> /* parse mount options */ >>> err = parse_options(sb, data); >>> if (err) > > > . >