From: Ted Ts'o Subject: Re: Bug In ext4 in kernels > 2.6.39 - Not mounting with arguments/options I specify in fstab on root remount Date: Sat, 22 Oct 2011 01:00:31 -0400 Message-ID: <20111022050031.GC4196@thunk.org> References: <4E6F1B49.3010803@gmail.com> <4E6F6D89.5040905@redhat.com> <20111009234433.GU7948@thunk.org> <4EA0E72D.8020305@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric Sandeen , linux-ext4@vger.kernel.org To: Matt Parnell Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:51263 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751883Ab1JVHtQ (ORCPT ); Sat, 22 Oct 2011 03:49:16 -0400 Content-Disposition: inline In-Reply-To: <4EA0E72D.8020305@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Oct 20, 2011 at 10:29:49PM -0500, Matt Parnell wrote: > The output of /proc/cmdline on 3.0.7: > > BOOT_IMAGE=/boot/vmlinuz26-zen root=/dev/sdb1 ro rootfstype=ext4 > rootflags=data=writeback noatime nodiratime barrier=0 discard > noinitrd > > > On 10/09/2011 06:44 PM, Ted Ts'o wrote: > >On Sun, Oct 09, 2011 at 05:10:54PM -0500, Matt Parnell wrote: > >>/proc/mounts (as you can see it's not being remounted rw for some > >>reason - /dev/sdc1 is the flash drive I used to pipe this info onto): > >> > >>rootfs / rootfs rw 0 0 > >>/dev/root / ext4 ro,relatime,barrier=1 0 0 I haven't had a chance to check on v3.0 (I'm currently travelling and penning this from an airplane), but on v3.1-rc3, it works for me under KVM. I fire up kvm-qemu this way: $QEMU -enable-kvm -boot order=c $NET \ -drive file=$ROOT_QCOW2,if=virtio$SNAPSHOT \ -drive file=$VDB,cache=none,if=virtio \ -drive file=$VDC,cache=none,if=virtio \ -drive file=$VDD,cache=none,if=virtio \ -nographic -smp $NR_CPU -m $MEM \ --kernel $KERNEL \ --append "root=/dev/vda console=ttyS0,115200 rootflags=data=writeback" |\ tee $LOGFILE with this in /proc/cmdline: candygram:~# cat /proc/cmdline root=/dev/vda console=ttyS0,115200 rootflags=data=writeback maint ... and this is what I have in /proc/mounts: candygram:~# head -2 /proc/mounts rootfs / rootfs rw 0 0 /dev/root / ext4 rw,noatime,user_xattr,acl,barrier=1,data=writeback 0 0 ... and what I have in /etc/fstab: UUID=ce4d6b98-2aa9-42d4-a127-995a795a0b02 / ext4 noatime,data=writeback 0 1 The kvm image I'm using is using Debian unstable image generated using debootstrap, and uses no modules or initrd's --- which makes it easier for me to boot since $KERNEL is set to: /tyt/linux/ext4/arch/x86/boot/bzImage This allows me to fire up test kernel right from my build tree, without needing to set up any kind of initrd nonsense. :-) - Ted