From patchwork Tue Sep 19 14:46:17 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Czerner X-Patchwork-Id: 9959211 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E7B37601E9 for ; Tue, 19 Sep 2017 14:46:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DD69428CD4 for ; Tue, 19 Sep 2017 14:46:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D0EF828D3E; Tue, 19 Sep 2017 14:46:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 790A028D00 for ; Tue, 19 Sep 2017 14:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751009AbdISOqX (ORCPT ); Tue, 19 Sep 2017 10:46:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38402 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbdISOqW (ORCPT ); Tue, 19 Sep 2017 10:46:22 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C5F9F4A6E9; Tue, 19 Sep 2017 14:46:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C5F9F4A6E9 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=lczerner@redhat.com Received: from rh_laptop (unknown [10.43.17.67]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 268A65C544; Tue, 19 Sep 2017 14:46:19 +0000 (UTC) Date: Tue, 19 Sep 2017 16:46:17 +0200 From: Lukas Czerner To: Markus Trippelsdorf Cc: Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org, Alexander Viro , linux-fsdevel@vger.kernel.org Subject: Re: mounting with lazytime doesn't work on ext4 Message-ID: <20170919144617.wh4raizggvwjpolg@rh_laptop> References: <20170918192644.GA232@x4> <20170919083506.GA233@x4> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170919083506.GA233@x4> User-Agent: NeoMutt/20170714 (1.8.3) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 19 Sep 2017 14:46:22 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue, Sep 19, 2017 at 10:35:06AM +0200, Markus Trippelsdorf wrote: > On 2017.09.18 at 21:26 +0200, Markus Trippelsdorf wrote: > > I switched back to ext4 yesterday, because my btrfs fs got corrupted. > > However mounting with lazytime doesn't work, neither specifying it in > > /etc/fstab nor a manual remount. It looks like the option is simply > > ignored. > > > > Strace shows, e.g.: > > > > # mount -o lazytime /boot > > mount("/dev/sdc2", "/boot", "ext4", MS_LAZYTIME, NULL) = 0 > > EXT4-fs (sdc2): mounted filesystem with ordered data mode. Opts: (null) > > /dev/sdc2 on /boot type ext4 (rw,relatime,data=ordered) > > > > # mount -o remount,lazytime /var > > mount("/dev/sdb2", "/var", 0x12c4460, MS_REMOUNT|MS_NOATIME|MS_LAZYTIME, NULL) = 0 > > EXT4-fs (sdb2): re-mounted. Opts: (null) > > /dev/sdb2 on /var type ext4 (rw,noatime,data=ordered) > > > > When I set "sb->s_flags |= MS_LAZYTIME;" unconditionally in > > fs/ext4/super.c:5057 (just deleting the if statement), then lazytime > > gets used when I remount. > > > > I'm running the latest git tree (4.14.0-rc1). > > The following patch seems to fix the issue for remounts: > > diff --git a/fs/namespace.c b/fs/namespace.c > index 54059b142d6b..d0b386706c5b 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -2322,6 +2322,9 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags, > if (err) > return err; > > + if (mnt_flags & MS_LAZYTIME) > + sb_flags |= MS_LAZYTIME; > + > down_write(&sb->s_umount); > if (ms_flags & MS_BIND) > err = change_mount_flags(path->mnt, ms_flags); > @@ -2809,6 +2812,8 @@ long do_mount(const char *dev_name, const char __user *dir_name, > mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME); > if (flags & SB_RDONLY) > mnt_flags |= MNT_READONLY; > + if (flags & MS_LAZYTIME) > + mnt_flags |= MS_LAZYTIME; Hi, this is definitely not right. Currently it seems that MS_LAZYTIME is supposed to be per sb option, even though I do not see a reason why it should not be per mnt options, in fact I'd prefer that. However the problem happened when e462ec50cb5fad19f6003a3d8087f4a0945dd2b1 switched from masking out per mnt flags to masking in per sb flags. However David missed SB_LAZYFLAG. The fix should be easy like this: I can send a proper patch, however maybe it would be better to convert it to per-mountpoint flags instead ? Any thoughts Ted ? -Lukas diff --git a/fs/namespace.c b/fs/namespace.c index 54059b1..3b48ef1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2823,7 +2823,8 @@ long do_mount(const char *dev_name, const char __user *dir_name, SB_MANDLOCK | SB_DIRSYNC | SB_SILENT | - SB_POSIXACL); + SB_POSIXACL | + SB_LAZYTIME); if (flags & MS_REMOUNT) retval = do_remount(&path, flags, sb_flags, mnt_flags,