From: =?UTF-8?B?SG9sZ2VyIEhvZmZzdMOkdHRl?= Subject: Re: Lazytime undone by/not working with remount? Date: Mon, 18 May 2015 17:36:52 +0200 Message-ID: <555A0714.8010806@googlemail.com> References: <55575399.6010801@googlemail.com> <20150518082135.GK4834@ws.net.home> <555A02CF.1000506@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-ext4@vger.kernel.org, Theodore Ts'o To: Eric Sandeen , Karel Zak Return-path: Received: from static.68.134.40.188.clients.your-server.de ([188.40.134.68]:50488 "EHLO mail02.iobjects.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751435AbbERPnb (ORCPT ); Mon, 18 May 2015 11:43:31 -0400 In-Reply-To: <555A02CF.1000506@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 05/18/15 17:18, Eric Sandeen wrote: > On 5/18/15 3:21 AM, Karel Zak wrote: >> On Sat, May 16, 2015 at 04:26:33PM +0200, Holger Hoffst=C3=A4tte wro= te: >>>> playing with lazytime on 4.0.4-rc1 + yesterday's fencepost patch) = I noticed >>>> something odd. Mounting secondary (non-root) partitions with lazyt= ime works >>>> fine, but / does not seem to retain the value from fstab - apparen= tly because >>>> it is remounted rw during boot, and lazytime gets swallowed/undone= =2E >>>> >>>> Same effect when trying to remount manually with lazytime: >>>> >>>> tux>findmnt / >>>> TARGET SOURCE FSTYPE OPTIONS >>>> / /dev/sda1 ext4 rw,noatime >>>> >>>> tux>mount -o lazytime,remount /=20 >>>> >>>> tux>dmesg=20 >>>> [ 5208.482505] EXT4-fs (sda1): re-mounted. Opts: (null) >>>> >>>> tux>findmnt / =20 >>>> TARGET SOURCE FSTYPE OPTIONS >>>> / /dev/sda1 ext4 rw,noatime >>>> >>>> tux>mount --version >>>> mount from util-linux 2.26.2 (libmount 2.26.0: assert, debug) >=20 > And what does /proc/mounts say? That'll tell you what is actually se= t > on the superblock. Works here, on 4.1.0-rc2: >=20 > # mount /dev/sdb1 /mnt/test > # mount -o remount,lazytime /mnt/test > # grep sdb1 /proc/mounts=20 > /dev/sdb1 /mnt/test ext4 rw,lazytime,seclabel,relatime,data=3Dordered= 0 0 >=20 > # dmesg | tail -n 2 > [516203.450943] EXT4-fs (sdb1): mounted filesystem with ordered data = mode. Opts: (null) > [516211.222020] EXT4-fs (sdb1): re-mounted. Opts: lazytime When I used util-linux 2.26.2 /proc/mounts never contained lazytime for= the root device (sda1), despite the fact that it and other partitions = explicitly had lazytime in fstab. Secondary drives & partitions *did* g= et the value right from the start, i.e. anything that didn't go through= a ro->remount transition. It all works reliably with 2.25.x since - as Karel mentioned - the bug = seems with ext4's remount logic in combination with readonly (as was th= e case with the root partition) and mount now actually sending the MS_L= AZYTIME flag, instead of relying on ext4's builtin extra handling. -h -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html