Re: [PATCH] mkefidisk: change filesystem to be writeable on grub

[Patrick Ohly <patrick.ohly@intel.com>]

On Thu, 2015-02-26 at 17:05 -0800, randy.e.witt@linux.intel.com wrote:
> >
> > On Qui, 2015-02-26 at 13:44 -0800, Randy Witt wrote:
> >> On 02/26/2015 11:29 AM, Bruno Bottazzini wrote:
> >> > This patch changes grub configuration so the filesystem will be
> >> writeable
> >> > instead, just read only when running the script.
> >> > ---
> >> >   scripts/contrib/mkefidisk.sh | 2 +-
> >> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >> >
> >> > diff --git a/scripts/contrib/mkefidisk.sh
> >> b/scripts/contrib/mkefidisk.sh
> >> > index b96b7d4..9b84831 100755
> >> > --- a/scripts/contrib/mkefidisk.sh
> >> > +++ b/scripts/contrib/mkefidisk.sh
> >> > @@ -342,7 +342,7 @@ if [ -e "$GRUB_CFG" ]; then
> >> >   	sed -i "s/ LABEL=[^ ]*/ /" $GRUB_CFG
> >> >
> >> >   	sed -i "s@ root=[^ ]*@ @" $GRUB_CFG
> >> > -	sed -i "s@vmlinuz @vmlinuz root=$TARGET_ROOTFS ro rootwait quiet @"
> >> $GRUB_CFG
> >> > +	sed -i "s@vmlinuz @vmlinuz root=$TARGET_ROOTFS rw rootwait quiet @"
> >> $GRUB_CFG
> >> >   fi
> >> >
> >> >   # Look for a gummiboot installation
> >> >
> >>
> >> This change basically reverts
> >> http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=24cd3ddeb70a3d3f2985ec71c87ae0108f3d2777
> >> by Darren. It also doesn't change the ro option when using gummiboot
> >> instead.
> >>
> >> What is this change trying to fix?
> >
> > Hello Randy,
> >
> > I got the following message:
> >  "file system is read-only"
> >
> > if I try to touch a file that is not on /tmp, or when I start a systemd
> > service that tries to write on the file system.
> >
> > After some research, I go it fixed by changing to read/write on the
> > script that was with read only.
> >
> > I thought this would be useful for someone else.
> 
> Thank you for taking the time to do this. If things still don't work after
> checking /etc/fstab, let us know.

I ran into the same issue, albeit not with a genuine Poky image, so I
didn't report it here. In my experience, even with a proper fstab
("defaults" for the rootfs or even "rw"), systemd-remount-fs never
remounted / as rw. When googling, I found references to the kernel boot
parameter, but as far as I remember, they said that this parameter had
been already obsoleted. It indeed did not seem to help to change it into
"rw" (but I'm no longer absolutely sure whether I tried that).

Sorry for being so vague :-/ Just wanted to confirm that there is indeed
something fishy and that running further experiments is needed.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.