On Fri,  6 Aug 2021 11:23:37 +0200
Daniel Gomez <daniel@qtec.com> wrote:

> When embeddding rootfs image (e.g. 'rootfs-dir') as a partition we
> might want to keep the stock fstab for that image. In such case, use
> this option to not update the fstab and use the stock one instead.
> 
> This option allows to specify which partitions get the updated fstab
> and which get the stock fstab.
> 
> Example:
>     part /export --source rootfs --rootfs-dir=hockeycam-image
>     --fstype=ext4 --label export --align 1024 --use-stock-fstab
> 
>     part / --source rootfs --fstype=ext4 --label rootfs --align 1024
> 
> Signed-off-by: Daniel Gomez <daniel@qtec.com>
> ---
> 
> The commit-id ce682a73b7447652f898ce1d1d0416a456df5416 reverted the
> functionality to restore the stock/original fstab file in a rootfs
> partition image (wic plugin).
> 
> Add back such functionality with an option to the user to select which
> fstab will be used for each partition by adding the --use-stock-fstab.
> In this case, the user will select whether or not the stock fstab will
> be updated or kept.
> 
> If you agree with the patch I'll adapt it to the master branch.
> 
> Daniel
> 
>  scripts/lib/wic/ksparser.py  | 1 +
>  scripts/lib/wic/partition.py | 3 ++-
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/lib/wic/ksparser.py b/scripts/lib/wic/ksparser.py
> index 452a160232..64933e0a5b 100644
> --- a/scripts/lib/wic/ksparser.py
> +++ b/scripts/lib/wic/ksparser.py
> @@ -184,6 +184,7 @@ class KickStart():
>          part.add_argument('--use-uuid', action='store_true')
>          part.add_argument('--uuid')
>          part.add_argument('--fsuuid')
> +        part.add_argument('--use-stock-fstab', action='store_true')
> 
>          bootloader = subparsers.add_parser('bootloader')
>          bootloader.add_argument('--append')
> diff --git a/scripts/lib/wic/partition.py b/scripts/lib/wic/partition.py
> index 85f9847047..c9e45773de 100644
> --- a/scripts/lib/wic/partition.py
> +++ b/scripts/lib/wic/partition.py
> @@ -54,6 +54,7 @@ class Partition():
>          self.uuid = args.uuid
>          self.fsuuid = args.fsuuid
>          self.type = args.type
> +        self.use_stock_fstab = args.use_stock_fstab
>          self.updated_fstab_path = None
>          self.has_fstab = False
>          self.update_fstab_in_rootfs = False
> @@ -286,7 +287,7 @@ class Partition():
>              (self.fstype, extraopts, rootfs, label_str, self.fsuuid, rootfs_dir)
>          exec_native_cmd(mkfs_cmd, native_sysroot, pseudo=pseudo)
> 
> -        if self.updated_fstab_path and self.has_fstab:
> +        if self.updated_fstab_path and self.has_fstab and not self.use_stock_fstab:
>              debugfs_script_path = os.path.join(cr_workdir, "debugfs_script")
>              with open(debugfs_script_path, "w") as f:
>                  f.write("cd etc\n")
> --
> 2.30.2
> 

You're only addressing ext2/3/4 partitions here. The patch needs to be
extended to cover the msdos partition case and the
update_fstab_in_rootfs case in the rootfs source plugin.

I also recommend changing the option in ksparser to '--no-fstab-update'
to match the argument you can pass to wic itself. That way you can pass
'--no-fstab-update' to wic to set the option for all partitions, or
include it in the wks file to set the option per-partition.

Thanks,

-- 
Paul Barker
https://pbarker.dev/