From 340fd0c8717c2bf33163a18bfec72243b0e51862 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Thu, 30 Aug 2012 15:43:17 +0800
Subject: [PATCH] Pass corret root= for nfsroot

References: bnc#774548, bsc#1069094
Patch-Mainline: no

Fix / is mounted on nfs. The fix is to pass kernel parameters
with correct root= for nfs. However since grub2 doesn't support
nfs file system module, the /boot on nfs is not possible and
grub2-probe not work in probing nfs mounted path. The fix is merely
on the script level and not use grub2-probe for above reasons.

v2: Filter out autofs and securityfs from /proc/self/mountinfo (bsc#1069094)
v3: Fix the wrong order of GRUB_FS/GRUB_DEVICE (bsc#1221904)

---
 util/grub-mkconfig.in |   37 ++++++++++++++++++++++++++++++-------
 1 files changed, 30 insertions(+), 7 deletions(-)

--- a/util/grub-mkconfig.in
+++ b/util/grub-mkconfig.in
@@ -131,26 +131,55 @@
     exit 1
 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
+probe_nfsroot_device () {
+    while read line ; do
+        part1=`echo $line | sed -e 's! - .*$!!'`
+        part2=`echo $line | sed -n -e 's! - \(.*\)$!\n\1!p' | sed 1d`
+
+        set -- $part1
+        path=$5
+
+        set -- $part2
+        fstype=$1
+        device=$2
+
+        if [ "x${path}" = "x/" ] &&
+           [ "x${fstype}" = "xnfs" -o "x${fstype}" = "xnfs4" ] ; then
+            echo "${fstype}:$device"
+            return
+        fi
+    done
+}
 
-# Device containing our /boot partition.  Usually the same as GRUB_DEVICE.
-GRUB_DEVICE_BOOT="`${grub_probe} --target=device /boot`"
-GRUB_DEVICE_BOOT_UUID="`${grub_probe} --device ${GRUB_DEVICE_BOOT} --target=fs_uuid 2> /dev/null`" || true
+NFSROOT_DEVICE="`awk '($9!="autofs")&&($9!="securityfs")' /proc/self/mountinfo | probe_nfsroot_device`"
 
 # Disable os-prober by default due to security reasons.
 GRUB_DISABLE_OS_PROBER="true"
 
-# Filesystem for the device containing our userland.  Used for stuff like
-# choosing Hurd filesystem module.
-GRUB_FS="`${grub_probe} --device ${GRUB_DEVICE} --target=fs 2> /dev/null || echo unknown`"
+if [ "x${NFSROOT_DEVICE}" != "x" ]; then
+    GRUB_DEVICE=""
+    GRUB_DEVICE_UUID=""
+    GRUB_DEVICE_PARTUUID=""
+    GRUB_FS="unknown"
+else
+    # Device containing our userland.  Typically used for root= parameter.
+    GRUB_DEVICE="`${grub_probe} --target=device /`"
+    # Filesystem for the device containing our userland.  Used for stuff like
+    # choosing Hurd filesystem module.
+    GRUB_FS="`${grub_probe} --device ${GRUB_DEVICE} --target=fs 2> /dev/null || echo unknown`"
+    GRUB_DEVICE_UUID="`${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
+fi
 
-if [ x"$GRUB_FS" = xunknown ]; then
+# Strive to circumvent grub to enable unsupported filesystem, for eg, nfsroot
+if [ x"$GRUB_FS" = x ] || [ x"$GRUB_FS" = xunknown ]; then
     GRUB_FS="$(stat -f -c %T / || echo unknown)"
 fi
 
+# Device containing our /boot partition.  Usually the same as GRUB_DEVICE.
+GRUB_DEVICE_BOOT="`${grub_probe} --target=device /boot`"
+GRUB_DEVICE_BOOT_UUID="`${grub_probe} --device ${GRUB_DEVICE_BOOT} --target=fs_uuid 2> /dev/null`" || true
+
 # Provide a default set of stock linux early initrd images.
 # Define here so the list can be modified in the sourced config file.
 if [ "x${GRUB_EARLY_INITRD_LINUX_STOCK}" = "x" ]; then
--- a/util/grub.d/10_linux.in
+++ b/util/grub.d/10_linux.in
@@ -88,6 +88,12 @@
   type="$3"
   args="$4"
 
+  if [ -n "${linux_root_device_thisversion}" ]; then
+    root_device="root=${linux_root_device_thisversion}"
+  else
+    root_device=""
+  fi
+
   if [ -z "$boot_device_id" ]; then
       boot_device_id="$(grub_get_device_id "${GRUB_DEVICE}")"
   fi
@@ -143,7 +149,7 @@
   message="$(gettext_printf "Loading Linux %s ..." ${version})"
   sed "s/^/$submenu_indentation/" << EOF
 	echo	'$(echo "$message" | grub_quote)'
-	linux	${rel_dirname}/${basename} root=${linux_root_device_thisversion} ${args}
+	linux	${rel_dirname}/${basename} ${root_device} ${args}
 EOF
   if test -n "${initrd}" ; then
     # TRANSLATORS: ramdisk isn't identifier. Should be translated.
--- a/util/grub.d/20_linux_xen.in
+++ b/util/grub.d/20_linux_xen.in
@@ -109,6 +109,11 @@
   args="$5"
   xen_args="$6"
   xsm="$7"
+  if [ -n "${linux_root_device_thisversion}" ]; then
+    root_device="root=${linux_root_device_thisversion}"
+  else
+    root_device=""
+  fi
   # If user wants to enable XSM support, make sure there's
   # corresponding policy file.
   xenpolicy=
@@ -160,7 +165,7 @@
         fi
 	${xen_loader}	${rel_xen_dirname}/${xen_basename} placeholder ${xen_args} \${xen_rm_opts}
 	echo	'$(echo "$lmessage" | grub_quote)'
-	${module_loader}	${rel_dirname}/${basename} placeholder root=${linux_root_device_thisversion} ${args}
+	${module_loader}	${rel_dirname}/${basename} placeholder ${root_device} ${args}
 EOF
   if test -n "${initrd}" ; then
     # TRANSLATORS: ramdisk isn't identifier. Should be translated.