root-hashes-gui.sh: generalize to work on debian/ubuntu/pureos/qubesos (luks+lvm; qubesos untested: I use btrfs)

Signed-off-by: Thierry Laurion <insurgo@riseup.net>

Author: tlaurion

initrd/bin/root-hashes-gui.sh

@@ -13,6 +13,7 @@ ROOT_MOUNT="/root"
 export CONFIG_ROOT_DIRLIST_PRETTY=$(echo $CONFIG_ROOT_DIRLIST | sed -e 's/^/\//;s/ / \//g')
 
 update_root_checksums() {
+  TRACE_FUNC
   if ! detect_root_device; then
     whiptail_error --title 'ERROR: No Valid Root Disk Found' \
       --msgbox "No Valid Root Disk Found" 0 80
@@ -31,6 +32,7 @@ update_root_checksums() {
     mount -o rw,remount /boot
   fi
 
+  DEBUG "calculating hashes for $CONFIG_ROOT_DIRLIST_PRETTY on $ROOT_MOUNT"
   echo "+++ Calculating hashes for all files in $CONFIG_ROOT_DIRLIST_PRETTY "
   # Intentional wordsplit
   # shellcheck disable=SC2086
@@ -47,6 +49,8 @@ update_root_checksums() {
   unmount_root_device
 }
 check_root_checksums() {
+  TRACE_FUNC
+  DEBUG "verifying existing hash file for $CONFIG_ROOT_DIRLIST_PRETTY"
   if ! detect_root_device; then
     whiptail_error --title 'ERROR: No Valid Root Disk Found' \
       --msgbox "No Valid Root Disk Found" 0 80
@@ -74,6 +78,7 @@ check_root_checksums() {
         update_root_checksums
         return 0
       else
+        DEBUG "user chose not to create root hash file, returning"
         exit 1
       fi
   fi
@@ -124,6 +129,7 @@ check_root_checksums() {
 
         return 0
       else
+        DEBUG "user chose not to update signatures after new-files warning"
         return 1
       fi
     fi
@@ -154,6 +160,7 @@ check_root_checksums() {
       update_root_checksums
       return 0
     else
+      DEBUG "user chose not to update signatures after hash-check-failure"
       return 1
     fi
   fi
@@ -164,21 +171,43 @@ check_root_checksums() {
 open_block_device_lvm() {
   TRACE_FUNC
   local VG="$1"
+  local LV MAPPER_VG MAPPER_LV name lvpath
 
   if ! lvm vgchange -ay "$VG"; then
     DEBUG "Can't open LVM VG: $VG"
     return 1
   fi
 
-  # Use the LV 'root'.  This is the default name used by Qubes.  There's no
-  # way to configure this at the moment.
-  if ! [ -e "/dev/mapper/$VG-root" ]; then
-    DEBUG "LVM volume group does not have 'root' logical volume"
+  # Prefer an LV named 'root' (used by Qubes), but fall back to any LV
+  # in the VG.  This ensures Ubuntu-style names (e.g. ubuntu-vg/ubuntu-root)
+  # also work.
+  LV="/dev/$VG/root"
+  if ! [ -e "$LV" ]; then
+    MAPPER_VG="${VG//-/--}"
+    LV="/dev/mapper/${MAPPER_VG}-root"
+  fi
+  if ! [ -e "$LV" ]; then
+    DEBUG "LVM VG $VG has no 'root' LV, enumerating all LVs"
+    # list LV names and try each one
+    for name in $(lvm lvs --noheadings -o lv_name --separator ' ' "$VG" 2>/dev/null); do
+      lvpath="/dev/$VG/$name"
+      if ! [ -e "$lvpath" ]; then
+        MAPPER_LV="${name//-/--}"
+        lvpath="/dev/mapper/${VG//-/--}-${MAPPER_LV}"
+      fi
+      if [ -e "$lvpath" ]; then
+        DEBUG "trying LV $lvpath"
+        LV="$lvpath"
+        break
+      fi
+    done
+  fi
+  if ! [ -e "$LV" ]; then
+    DEBUG "no usable LV found in VG $VG"
     return 1
   fi
-
-  # Use the root LV now
-  open_block_device_layers "/dev/mapper/$VG-root"
+  # Use selected LV
+  open_block_device_layers "$LV"
 }
 
 # Open a LUKS device, then continue looking for more layers.
@@ -269,12 +298,21 @@ open_root_device_no_clean_up() {
 close_block_device_lvm() {
   TRACE_FUNC
   local VG="$1"
+  local name lvpath MAPPER_VG MAPPER_LV
 
-  # We always use the LV 'root' currently
-  local LV="/dev/mapper/$VG-root"
-  if [ -e "$LV" ]; then
-    close_block_device_layers "$LV"
-  fi
+  MAPPER_VG="${VG//-/--}"
+
+  # Close any layers found in all LVs in this VG, not just 'root'.
+  for name in $(lvm lvs --noheadings -o lv_name --separator ' ' "$VG" 2>/dev/null); do
+    lvpath="/dev/$VG/$name"
+    if ! [ -e "$lvpath" ]; then
+      MAPPER_LV="${name//-/--}"
+      lvpath="/dev/mapper/${MAPPER_VG}-${MAPPER_LV}"
+    fi
+    if [ -e "$lvpath" ]; then
+      close_block_device_layers "$lvpath"
+    fi
+  done
 
   # The LVM VG might be open even if no 'root' LV exists, still try to close it.
   lvm vgchange -an "$VG" || \
@@ -368,6 +406,7 @@ detect_root_device()
 
   # generate list of possible boot devices
   fdisk -l 2>/dev/null | grep "Disk /dev/" | cut -f2 -d " " | cut -f1 -d ":" > /tmp/disklist
+  DEBUG "detect_root_device: initial disklist=$(cat /tmp/disklist | tr '\n' ' ')"
 
   # filter out extraneous options
   > /tmp_root_device_list