Adding Nicholas...
On Mon, Sep 30, 2019 at 04:59:12PM +0200, Javier Martinez Canillas wrote:
From: Peter Jones <address@hidden>
The grub-mkconfig and 10_linux scripts by default attempt to use a UUID to
set the root kernel command line parameter and the $root GRUB environment
variable.
The former can be disabled by setting the GRUB_DISABLE_LINUX_UUID variable
to "true", but there is currently no way to disable the latter.
The generated grub config uses the search command with the --fs-uuid option
to find the device that has to be set as $root, i.e:
search --no-floppy --fs-uuid --set=root ...
This is usually more reliable but in some cases it may not be appropriate,
so this patch introduces a new GRUB_DISABLE_UUID variable that can be used
to disable searching for the $root device by filesystem UUID.
When disabled, the $root device will be set to the value specified in the
device.map as found by the grub-probe --target=compatibility_hint option.
When setting GRUB_DISABLE_UUID=true, the GRUB_DISABLE_LINUX_UUID and
GRUB_DISABLE_LINUX_PARTUUID variables will also be set to "true" unless
these have been explicitly set to "false".
That way, the GRUB_DISABLE_UUID variable can be used to force using the
device names for both GRUB and Linux.
Signed-off-by: Peter Jones <address@hidden>
Signed-off-by: Javier Martinez Canillas <address@hidden>
In general "Reviewed-by: Daniel Kiper <address@hidden>" but I would
like to hear Nicholas opinions here too >
Daniel
---
Changes since v1 (suggested by Daniel Kiper):
- Explain better in the commit message why the GRUB_DISABLE_UUID variable
is needed and the difference with the existing GRUB_DISABLE_LINUX_UUID/
GRUB_DISABLE_LINUX_PARTUUID variables.
- Remove logic that disabled setting the root cmdline param to either the
filesystem UUID or partition UUID and instead use the existing variables
to disable this.
docs/grub.texi | 9 +++++++++
util/grub-mkconfig.in | 10 ++++++++++
util/grub-mkconfig_lib.in | 4 ++--
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/docs/grub.texi b/docs/grub.texi
index 5ac61c09d1b..2fe0e1b83bb 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -1441,6 +1441,15 @@ enable the use of partition UUIDs, set this option to
@samp{false}.
If this option is set to @samp{true}, disable the generation of recovery
mode menu entries.
+@item GRUB_DISABLE_UUID
+Normally, @command{grub-mkconfig} will generate menu entries that use
+universally-unique identifiers (UUIDs) to identify various filesystems to
+search for files. This is usually more reliable, but in some cases it may
+not be appropriate. To disable this use of UUIDs, set this option to
+@samp{true}. Setting this option to @samp{true}, will also set the options
+@samp{GRUB_DISABLE_LINUX_UUID} and @samp{GRUB_DISABLE_LINUX_PARTUUID} to
+@samp{true}, unless they have been explicilty set to @samp{false}.
+
@item GRUB_VIDEO_BACKEND
If graphical video support is required, either because the @samp{gfxterm}
graphical terminal is in use or because @samp{GRUB_GFXPAYLOAD_LINUX} is set,
diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
index a6ce375ed18..2537dbca2f9 100644
--- a/util/grub-mkconfig.in
+++ b/util/grub-mkconfig.in
@@ -158,6 +158,15 @@ if test -f ${sysconfdir}/default/grub ; then
. ${sysconfdir}/default/grub
fi
+if [ "x${GRUB_DISABLE_UUID}" = "xtrue" ]; then
+ if [ "x${GRUB_DISABLE_LINUX_UUID}" != "xfalse" ]; then
+ GRUB_DISABLE_LINUX_UUID="true"
+ fi
+ if [ "x${GRUB_DISABLE_LINUX_PARTUUID}" != "xfalse" ]; then
+ GRUB_DISABLE_LINUX_PARTUUID="true"
+ fi
+fi
+
# XXX: should this be deprecated at some point?
if [ "x${GRUB_TERMINAL}" != "x" ] ; then
GRUB_TERMINAL_INPUT="${GRUB_TERMINAL}"
@@ -227,6 +236,7 @@ export GRUB_DEFAULT \
GRUB_DISABLE_LINUX_UUID \
GRUB_DISABLE_LINUX_PARTUUID \
GRUB_DISABLE_RECOVERY \
+ GRUB_DISABLE_UUID \
GRUB_VIDEO_BACKEND \
GRUB_GFXMODE \
GRUB_BACKGROUND \
diff --git a/util/grub-mkconfig_lib.in b/util/grub-mkconfig_lib.in
index 0f801cab3e4..3e12b2c0e6a 100644
--- a/util/grub-mkconfig_lib.in
+++ b/util/grub-mkconfig_lib.in
@@ -156,7 +156,7 @@ prepare_grub_to_access_device ()
if [ "x$fs_hint" != x ]; then
echo "set root='$fs_hint'"
fi
- if fs_uuid="`"${grub_probe}" --device $@ --target=fs_uuid 2> /dev/null`" ;
then
+ if [ "x${GRUB_DISABLE_UUID}" != "xtrue" ] && fs_uuid="`"${grub_probe}" --device $@
--target=fs_uuid 2> /dev/null`" ; then
hints="`"${grub_probe}" --device $@ --target=hints_string 2> /dev/null`"
|| hints=
echo "if [ x\$feature_platform_search_hint = xy ]; then"
echo " search --no-floppy --fs-uuid --set=root ${hints} ${fs_uuid}"
@@ -173,7 +173,7 @@ grub_get_device_id ()
IFS='
'
device="$1"
- if fs_uuid="`"${grub_probe}" --device ${device} --target=fs_uuid 2>
/dev/null`" ; then
+ if [ "x${GRUB_DISABLE_UUID}" != "xtrue" ] && fs_uuid="`"${grub_probe}" --device
${device} --target=fs_uuid 2> /dev/null`" ; then
echo "$fs_uuid";
else
echo $device |sed 's, ,_,g'
--
2.21.0