Re: [GRUB PARTUUID PATCH 2/2] Update grub script template files

[Andrei Borzenkov <arvidjaar@gmail.com>]

20.06.2016 04:37, Nicholas Vinson пишет:
> Update grub-mkconfig.in and 10_linux.in to support grub-probe's new
> partuuid target.
> 
> Signed-off-by: Nicholas Vinson <nvinson234@gmail.com>
> ---
>  util/grub-mkconfig.in   |  2 ++
>  util/grub.d/10_linux.in | 11 +++++++++--
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
> index f8496d2..fc42462 100644
> --- a/util/grub-mkconfig.in
> +++ b/util/grub-mkconfig.in
> @@ -134,6 +134,7 @@ fi
>  # Device containing our userland.  Typically used for root= parameter.
>  GRUB_DEVICE="`${grub_probe} --target=device /`"
>  GRUB_DEVICE_UUID="`${grub_probe} --device ${GRUB_DEVICE} --target=fs_uuid 2> /dev/null`" || true
> +GRUB_DEVICE_PARTUUID="`${grub_probe} --device ${GRUB_DEVICE} --target=partuuid 2> /dev/null`" || true
>  
>  # Device containing our /boot partition.  Usually the same as GRUB_DEVICE.
>  GRUB_DEVICE_BOOT="`${grub_probe} --target=device /boot`"
> @@ -182,6 +183,7 @@ if [ "x${GRUB_ACTUAL_DEFAULT}" = "xsaved" ] ; then GRUB_ACTUAL_DEFAULT="`"${grub
>  # override them.
>  export GRUB_DEVICE \
>    GRUB_DEVICE_UUID \
> +  GRUB_DEVICE_PARTUUID \
>    GRUB_DEVICE_BOOT \
>    GRUB_DEVICE_BOOT_UUID \
>    GRUB_FS \
> diff --git a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
> index de9044c..8081fdb 100644
> --- a/util/grub.d/10_linux.in
> +++ b/util/grub.d/10_linux.in
> @@ -220,8 +220,15 @@ while [ "x$list" != "x" ] ; do
>      gettext_printf "Found initrd image: %s\n" "${dirname}/${initrd}" >&2
>    elif test -z "${initramfs}" ; then
>      # "UUID=" and "ZFS=" magic is parsed by initrd or initramfs.  Since there's
> -    # no initrd or builtin initramfs, it can't work here.
> -    linux_root_device_thisversion=${GRUB_DEVICE}
> +    # no initrd or builtin initramfs, it can't work here.  However, if
> +    # GRUB_DEVICE_PARTUUID is not empty we can use that here if
> +    # GRUD_DISABLE_LINUX_UUID is not set to true.
> +    if [ "x${GRUB_DISABLE_LINUX_UUID}" != "xtrue" ]
> +        && [ "x${GRUB_DEVICE_PARTUUID}" != "x" ]; then
> +        linux_root_device_thisversion="PARTUUID=${GRUB_DEVICE_PARTUUID}"

Well, PARTUUID appeared first in 2.6.37 and MSDOS "UUID" in 3.10.
Unfortunately we have no way to check for it, even as fragile as stored
kernel config. So I am not sure we should do it by default. And if we
add some extra knob to turn it on, as you mentioned yourself, you can
simply add root=PARTUUID=xxx to stored kernel command line.

One more consideration is that reinstalling in existing partition will
invalidate FS UUID stored in grub.cfg which is arguably the right thing
because you now have something different there, but PARTUUID will most
likely remain the same.

> +    else
> +        linux_root_device_thisversion=${GRUB_DEVICE}
> +    fi
>    fi
>  
>    if [ "x$is_top_level" = xtrue ] && [ "x${GRUB_DISABLE_SUBMENU}" != xy ]; then
>