* Re: sd .img partition loop support
[not found] <CADmzSSgquwg49GfMNSxi6KRcvq2nxPhwtiH311D+Ux_VTuE+fA@mail.gmail.com>
@ 2021-10-18 18:45 ` Carl Karsten
2021-10-19 6:53 ` Amir Goldstein
0 siblings, 1 reply; 3+ messages in thread
From: Carl Karsten @ 2021-10-18 18:45 UTC (permalink / raw)
To: linux-unionfs
I'm trying to overlay an empty upper dir onto a fat/loop/img fs and getting:
juser@negk:~/boot$ sudo mount -o ro /dev/mapper/loop0p1 img
juser@negk:~/boot$ sudo mount -t overlay overlay
-olowerdir=img,upperdir=upper,workdir=work merged
mount: /home/juser/boot/merged: wrong fs type, bad option, bad superblock
on overlay, missing codepage or helper program, or other error.
[ 2449.670177] overlayfs: filesystem on 'lower' not supported
code to replicate:
mkdir boot
cd boot
mkdir img lower upper work merged
wget http://downloads.raspberrypi.org/raspios_lite_armhf/images/raspios_lite_armhf-2020-05-28/2020-05-27-raspios-buster-lite-armhf.zip
unzip 2020-05-27-raspios-buster-lite-armhf.zip
sudo kpartx -av 2020-05-27-raspios-buster-lite-armhf.img
sudo mount /dev/mapper/loop0p1 img
# this errors:
sudo mount -t overlay overlay -olowerdir=img,upperdir=upper,workdir=work
merged
# this does not
cp img/* lower/
sudo mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work
merged
https://github.com/CarlFK/pici/blob/main/test1.sh
The goal is to netboot a pi using the files from the .img with a few
changes, the root kernel parameter needs to be changed from local storage
to nfs:
# tftp/cmdline.txt
root=/dev/nfs nfsroot=10.21.0.1:/srv/nfs/rpi/root,vers=4.1,proto=tcp rw
ip=dhcp rootwait elevator=deadline consoleblank=0
I can copy all the files from the .img into a dir, but I am thinking I
should be able to overlay a dir on top to manage the changes.
If you want to see my netboot pi server setup
https://github.com/CarlFK/pici/blob/main/setup.md
--
Carl K
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: sd .img partition loop support
2021-10-18 18:45 ` sd .img partition loop support Carl Karsten
@ 2021-10-19 6:53 ` Amir Goldstein
2021-10-19 15:29 ` Carl Karsten
0 siblings, 1 reply; 3+ messages in thread
From: Amir Goldstein @ 2021-10-19 6:53 UTC (permalink / raw)
To: Carl Karsten; +Cc: overlayfs
On Mon, Oct 18, 2021 at 9:46 PM Carl Karsten <carl@nextdayvideo.com> wrote:
>
> I'm trying to overlay an empty upper dir onto a fat/loop/img fs and getting:
>
> juser@negk:~/boot$ sudo mount -o ro /dev/mapper/loop0p1 img
> juser@negk:~/boot$ sudo mount -t overlay overlay
> -olowerdir=img,upperdir=upper,workdir=work merged
> mount: /home/juser/boot/merged: wrong fs type, bad option, bad superblock
> on overlay, missing codepage or helper program, or other error.
>
> [ 2449.670177] overlayfs: filesystem on 'lower' not supported
>
fat was never supported as lower or upper layer AFAIK, see:
https://lore.kernel.org/linux-unionfs/2527352.xHhNOModH5@nerdopolis/
This is due to the case insensitive and special name encoding of fat.
It is not unfixable, but it was never a priority for anyone to fix it.
I suppose it would be easier for you to copy the image to another filesystem
before constructing the overlay.
Thanks,
Amir.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: sd .img partition loop support
2021-10-19 6:53 ` Amir Goldstein
@ 2021-10-19 15:29 ` Carl Karsten
0 siblings, 0 replies; 3+ messages in thread
From: Carl Karsten @ 2021-10-19 15:29 UTC (permalink / raw)
To: Amir Goldstein; +Cc: overlayfs
case insensitive, I can see how that would be a problem.
Now that I understand that I'll stop trying to make it work
thank you.
On Tue, Oct 19, 2021 at 1:53 AM Amir Goldstein <amir73il@gmail.com> wrote:
>
> On Mon, Oct 18, 2021 at 9:46 PM Carl Karsten <carl@nextdayvideo.com> wrote:
> >
> > I'm trying to overlay an empty upper dir onto a fat/loop/img fs and getting:
> >
> > juser@negk:~/boot$ sudo mount -o ro /dev/mapper/loop0p1 img
> > juser@negk:~/boot$ sudo mount -t overlay overlay
> > -olowerdir=img,upperdir=upper,workdir=work merged
> > mount: /home/juser/boot/merged: wrong fs type, bad option, bad superblock
> > on overlay, missing codepage or helper program, or other error.
> >
> > [ 2449.670177] overlayfs: filesystem on 'lower' not supported
> >
>
> fat was never supported as lower or upper layer AFAIK, see:
> https://lore.kernel.org/linux-unionfs/2527352.xHhNOModH5@nerdopolis/
>
> This is due to the case insensitive and special name encoding of fat.
> It is not unfixable, but it was never a priority for anyone to fix it.
>
> I suppose it would be easier for you to copy the image to another filesystem
> before constructing the overlay.
>
> Thanks,
> Amir.
--
Carl K
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-10-18 18:45 ` sd .img partition loop support Carl Karsten
2021-10-19 6:53 ` Amir Goldstein
2021-10-19 15:29 ` Carl Karsten
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