Re: [PATCH] image: remove / entry from fstab template

[Henning Schild <henning.schild@siemens.com>]

Am Tue, 4 Oct 2022 13:54:38 +0200
schrieb Jan Kiszka <jan.kiszka@siemens.com>:

> On 04.10.22 13:46, Henning Schild wrote:
> > An fstab entry for / should usually not be required. It just makes a
> > rootfs less portable (USB vs. NFS, vs. SSD). The kernel is the one
> > that should know which fs to mount and how. That is done via a
> > bootloader.
> > 
> > Should additional mount options be needed for a concrete image, an
> > imager like wic might add an entry. i.e. for adding fspassno or
> > x-systemd.growfs
> > 
> > So to make the rootfs more generic and to allow imagers to add their
> > individual / lines, instead of having to modify an existing one,
> > remove the line from the template.
> > 
> > Signed-off-by: Henning Schild <henning.schild@siemens.com>
> > ---
> >  meta/classes/image.bbclass | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
> > index ccff81066178..d8d605d3af07 100644
> > --- a/meta/classes/image.bbclass
> > +++ b/meta/classes/image.bbclass
> > @@ -327,7 +327,6 @@ image_configure_fstab[weight] = "2"
> >  image_configure_fstab() {
> >      sudo tee '${IMAGE_ROOTFS}/etc/fstab' << EOF
> >  # Begin /etc/fstab
> > -/dev/root	/		auto
> > defaults		0	0 proc		/proc
> > 	proc		nosuid,noexec,nodev	0	0
> > sysfs		/sys		sysfs
> > nosuid,noexec,nodev	0	0 devpts
> > /dev/pts	devpts		gid=5,mode=620
> > 0	0  
> 
> This works also for other imagers than wic? Just poking to avoid that
> we miss the case where this was once added for (if that exists).

AFAIK there are no other imagers that create fully bootable images. We
have ext4, probably usually combined with "qemu -kernel" as
"bootloader". And "tar.gz" usually combined with NFS and pxeboot or any
other external bootloader like uboot on a flash.
Both should remain working without the line, at least for qemu CI will
shortly tell. And for NFS i am pretty sure it will just work. I can
test that on request.

Looking at its git history, that is very old and hard to say why it was
ever done like that. Likely predates systemd and was taken from an
older OE or raspbian.

Henning

> Jan
>