sys: improve device/partition discovery

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [core] wrap report email body to 1000 characters by default (DEBBUG-871793)
 - [core] improve error handling around `reporthost` feature
 - [docs] add missing parameters to `backupninja.conf` manpage
+- [sys] improve device selection for MBR backup (#11303)
 
 ## [1.2.0] - 2021-01-21
 

handlers/sys.in

@@ -554,24 +554,39 @@ fi
 
 ## PARTITIONS #############################
 
-# here we use sfdisk to dump a listing of all the partitions.
-# these files can be used to directly partition a disk of the same size.
-
-if [ "$partitions" == "yes" ]; then
-   if [ "$dosfdisk" == "yes" ]; then
+if [ "$partitions" == "yes" ] || [ "$luksheaders" == "yes" ] || [ "$mbr" == "yes" ]; then
+   # get a list of block devices on the system
+   debug "LC_ALL=C $LSBLK --output NAME,TYPE --list --paths 2>/dev/null | grep \"disk$\" | grep -v '^/dev/zram' | @AWK@ '{print \$1}'"
    devices=`LC_ALL=C $LSBLK --output NAME,TYPE --list --paths 2>/dev/null | grep "disk$" | grep -v '^/dev/zram' | @AWK@ '{print $1}'`
-      partitions=`LC_ALL=C $SFDISK -l 2>/dev/null |grep "^/dev" | @AWK@ '{print $1}'`
+
    if [ "$devices" == "" ]; then
-         warning "No harddisks found"
+      warning "Unable to find any block devices on this system."
+   else
+      info "$(echo "Devices found: $devices" |  tr "\n" " ")"
    fi
+
+   # get a list of block device partitions on the system
+   debug "LC_ALL=C $SFDISK -l 2>/dev/null | grep \"^/dev\" | @AWK@ '{print \$1}'"
+   devparts=`LC_ALL=C $SFDISK -l 2>/dev/null | grep "^/dev" | @AWK@ '{print $1}'`
+
+   if [ "$devparts" == "" ]; then
+      info "No partitions found on this system."
+   else
+      info "$(echo "Partitions found: $partitions" | tr "\n" " ")"
+   fi
+fi
+
+if [ "$partitions" == "yes" ]; then
+   if [ "$dosfdisk" == "yes" ]; then
       for dev in $devices; do
-         debug "$SFDISK will try to backup partition tables for device $dev"
          [ -b $dev ] || continue
-         echo "${partitions}" | grep -q "${dev}"
-         if [ $? -ne 0 ] ; then
+         if ! echo "${devparts}" | grep -q "${dev}"; then
              info "The device $dev does not appear to have any partitions"
              continue
          fi
+         # here we use sfdisk to dump a listing of all the partitions.
+         # these files can be used to directly partition a disk of the same size.
+         debug "$SFDISK will try to backup partition tables for device $dev"
          label=${dev#/dev/}
          label=${label//\//-}
          outputfile=${partitionsfile//__star__/$label}
@@ -590,24 +605,13 @@ if [ "$partitions" == "yes" ]; then
 fi
 
 if [ "$luksheaders" == "yes" ]; then
-   devices=`LC_ALL=C $LSBLK --output NAME,TYPE --list --paths 2>/dev/null | grep "disk$" | grep -v '^/dev/zram' | @AWK@ '{print $1}'`
-   if [ "$devices" == "" ]; then
-      warning "No harddisks found"
-   fi
-   partitions=`LC_ALL=C $SFDISK -l 2>/dev/null |grep "^/dev" | @AWK@ '{print $1}'`
-   [ -n "$partitions" ] || warning "No partitions found"
-   targetdevices=""
-   for dev in $devices $partitions; do
+   for dev in $devices $devparts; do
       [ -b $dev ] || continue
-      debug "$CRYPTSETUP isLuks $dev"
-      $CRYPTSETUP isLuks $dev
-      [ $? -eq 0 ] && targetdevices="$targetdevices $dev"
-   done
-   for dev in $targetdevices; do
+      if $CRYPTSETUP isLuks $dev; then
          label=${dev#/dev/}
          label=${label//\//-}
          outputfile=${luksheadersfile//__star__/$label}
-      debug "Let us backup the LUKS header of $dev"
+         debug "$CRYPTSETUP will try to backup the LUKS header for device $dev"
          debug "$CRYPTSETUP luksHeaderBackup \"${dev}\" --header-backup-file \"${outputfile}\""
          output=`$CRYPTSETUP luksHeaderBackup "${dev}" --header-backup-file "${outputfile}" 2>&1`
          exit_code=$?
@@ -618,17 +622,15 @@ if [ "$luksheaders" == "yes" ]; then
             debug "$output"
             fatal "The LUKS header of $dev could not be saved."
          fi
+      fi
    done
 fi
 
 if [ "$mbr" == "yes" ]; then
-   devices=`LC_ALL=C $SFDISK -l 2>/dev/null | grep "^Disk /dev" | @AWK@ '{print $2}' | cut -d: -f1`
-   if [ "$devices" == "" ]; then
-      warning "No harddisks found"
-   fi
    for dev in $devices; do
-      debug "Will try to backup MBR tables for device $dev"
       [ -b $dev ] || continue
+      if $SFDISK -d $dev 2>/dev/null | head -n1 | grep "label: dos"; then
+         debug "$SFDISK will try to backup MBR tables for device $dev"
          label=${dev#/dev/}
          label=${label//\//-}
          outputfile=${mbrfile//__star__/$label}
@@ -637,6 +639,9 @@ if [ "$mbr" == "yes" ]; then
          if [ $? -ne 0 ]; then
             warning "The MBR for $dev could not be saved."
          fi
+      else
+         info "The device $dev does not appear to contain an MBR."
+      fi
    done
 fi