Re: Bug In ext4 in kernels > 2.6.39 - Not mounting with arguments/options I specify in fstab on root remount

[Matt Parnell <mparnell@gmail.com>]

That doesn't really help me at all, it's not rootflags=data=writeback 
causing this, it's starting to make me think that arch's init may be to 
blame, although I previously ruled it out...

This is all a big wtf though. I'm going to go complain at the arch devs 
now... I've not finished porting openrc to it yet.

On 10/22/2011 12:00 AM, Ted Ts'o wrote:
> 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