Include kernel paremeteres from grub file and fix mapdevfs function

The `grub2-mkconfig` tool is usually re-run when a new filesystem is
mounted so the new menuentry produced can be use on the next
boot. However the new created linux command (on the new entry)
has only the root parameter and it is invalid for mapper devices.

The proposed changes tries to source the grub's default environment file
if present so it can be used to create a more complete kernel command
line and fixes the kernel's root value, where it takes the symlink
instead of the cannonical file, allowing device mapper types to boot
in a consistent way.

Resolves: #RHEL-55234
Signed-off-by: Leo Sandoval <lsandova@redhat.com>

os-prober-90fallback-include-possible-kernel-parameters-from-g.patch

@@ -0,0 +1,53 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Leo Sandoval <lsandova@redhat.com>
+Date: Thu, 27 Jun 2024 10:53:32 -0600
+Subject: [PATCH] 90fallback: include possible kernel parameters from grub's
+ default file
+
+Probed filesystems may include the GRUB's default
+file ($mpoint/etc/default/grub) so it desirable to source it and get
+and place either GRUB_CMDLINE_LINUX and/or GRUB_CMDLINE_LINUX_DEFAULT
+on the kernel parameters field, ultimately tools like grub2-mkconfig
+makes use of it and create menuentries with kernel parameters.
+
+Signed-off-by: Leo Sandoval <lsandova@redhat.com>
+---
+ linux-boot-probes/mounted/common/90fallback | 18 +++++++++++++++++-
+ 1 file changed, 17 insertions(+), 1 deletion(-)
+
+diff --git a/linux-boot-probes/mounted/common/90fallback b/linux-boot-probes/mounted/common/90fallback
+index 7e40d15..cad7645 100755
+--- a/linux-boot-probes/mounted/common/90fallback
++++ b/linux-boot-probes/mounted/common/90fallback
+@@ -10,6 +10,22 @@ mpoint="$3"
+ type="$4"
+ 
+ mappedpartition=$(mapdevfs "$partition" 2>/dev/null) || mappedpartition="$partition"
++kernparams="root=$mappedpartition"
++
++# In case there is $mpoint/etc/default/grub, source it and take into account
++# relevant command line variables. This function must be run inside a subshell
++# otherwise grub default variable may be overriden
++get_cmdline_linux_params()
++{
++    local mpoint_sysconfdir="$mpoint/etc"
++    if test -f ${mpoint_sysconfdir}/default/grub ; then
++	unset GRUB_CMDLINE_LINUX GRUB_CMDLINE_LINUX_DEFAULT
++	. ${mpoint_sysconfdir}/default/grub
++	echo "${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_LINUX_DEFAULT}"
++    fi
++}
++
++kernparams="$(echo $kernparams $(get_cmdline_linux_params) | sed 's/[[:space:]]\+$//')"
+ 
+ exitcode=1
+ for kernpat in /vmlinuz /vmlinux /boot/vmlinuz /boot/vmlinux "/boot/vmlinuz*" \
+@@ -38,7 +54,7 @@ for kernpat in /vmlinuz /vmlinux /boot/vmlinuz /boot/vmlinux "/boot/vmlinuz*" \
+ 			for initrd in $(eval ls "$initrdname" "$initrdname1" "$initrdname2" "$initrdname3" "$initrdname4" 2>/dev/null); do
+ 				if [ "$initrd" != "$kernfile" ] && [ -f "$initrd" ] && [ ! -L "$initrd" ]; then
+ 					initrd=$(echo "$initrd" | sed "s!^$mpoint!!")
+-					result "$partition:$kernbootpart::$kernbasefile:$initrd:root=$mappedpartition"
++					result "$partition:$kernbootpart::$kernbasefile:$initrd:$kernparams"
+ 					exitcode=0
+ 					foundinitrd=1
+ 				fi

os-prober-common.sh-do-not-resolve-symbolic-link-on-mapped-dev.patch

@@ -0,0 +1,27 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Leo Sandoval <lsandova@redhat.com>
+Date: Thu, 27 Jun 2024 11:31:38 -0600
+Subject: [PATCH] common.sh: do not resolve symbolic link on mapped device
+ filesystems
+
+/dev/dm-* devices may change from boot to boot so better to use the
+symlink instead of the resolved file name
+
+Signed-off-by: Leo Sandoval <lsandova@redhat.com>
+---
+ common.sh | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/common.sh b/common.sh
+index a24286a..f0ebfb3 100644
+--- a/common.sh
++++ b/common.sh
+@@ -92,7 +92,7 @@ export fd_result  # so subshells inherit current value by default
+ # shim to make it easier to use os-prober outside d-i
+ if ! type mapdevfs >/dev/null 2>&1; then
+   mapdevfs () {
+-    readlink -f "$1"
++    echo "$1"
+   }
+ fi
+ 

os-prober.spec

@@ -1,6 +1,6 @@
 Name:           os-prober
 Version:        1.74
-Release:        9%{?dist}
+Release:        10%{?dist}
 Summary:        Probes disks on the system for installed operating systems
 
 Group:          System Environment/Base
@@ -21,6 +21,8 @@ Patch7:         os-prober-umount-fix.patch
 Patch8:         os-prober-grub2-parsefix.patch
 Patch9:         os-prober-grepfix.patch
 Patch10:        os-prober-gentoo-fix.patch
+Patch11:        os-prober-90fallback-include-possible-kernel-parameters-from-g.patch
+Patch12:        os-prober-common.sh-do-not-resolve-symbolic-link-on-mapped-dev.patch
 
 Requires:       udev coreutils util-linux
 Requires:       grep /bin/sed /sbin/modprobe
@@ -86,6 +88,11 @@ fi
 %{_var}/lib/%{name}
 
 %changelog
+* Mon Sep 2 2024 Leo Sandoval <lsandova@redhat.com> - 1.74-10
+- 90fallback: include possible kernel parameters from grub's default file
+- common.sh: do not resolve symbolic link on mapped device filesystems
+- Resolves: #RHEL-55234
+
 * Tue Jun 22 2021 Javier Martinez Canillas <javierm@redhat.com> - 1.74-9
 - Another build but with a gating.yaml to allow leaving gating
   Resolves: rhbz#1624158