Better is_multipath_path function (issue #2298) plus lsblk output as …

…disklayout.conf header plus TODO comments in layout/prepare/default/010_prepare_files.sh

usr/share/rear/layout/prepare/default/010_prepare_files.sh

@@ -11,37 +11,40 @@ LUN_WWID_MAP="$VAR_DIR/layout/lun_wwid_mapping"
 
 # Touchfiles for layout recreation.
 LAYOUT_TOUCHDIR="$TMP_DIR/touch"
-if [ -e $LAYOUT_TOUCHDIR ] ; then
-    rm -rf $LAYOUT_TOUCHDIR
-fi
+test -e $LAYOUT_TOUCHDIR && rm -rf $LAYOUT_TOUCHDIR
 mkdir -p $LAYOUT_TOUCHDIR
 
-if [ -e $LAYOUT_FILE ] ; then
-    save_original_file $LAYOUT_FILE
-fi
+test -e $LAYOUT_FILE && save_original_file $LAYOUT_FILE
 
-if [ -e $CONFIG_DIR/disklayout.conf ] ; then
+if test -e $CONFIG_DIR/disklayout.conf ; then
     cp $CONFIG_DIR/disklayout.conf $LAYOUT_FILE
     # Only set MIGRATION_MODE if not already set (could be already specified by the user):
     if ! test "$MIGRATION_MODE" ; then
         MIGRATION_MODE='true'
         LogPrint "Switching to manual disk layout configuration ($CONFIG_DIR/disklayout.conf exists)"
     fi
-
-    if [ -e $CONFIG_DIR/lun_wwid_mapping.conf ] ; then
+    # For the LUN WWIDs migration code see finalize/GNU/Linux/250_migrate_lun_wwid.sh
+    # TODO: Why are LUN WWIDs migrated only if also $CONFIG_DIR/disklayout.conf exists?
+    # Why are LUN WWIDs not always migrated when only $CONFIG_DIR/lun_wwid_mapping.conf exists?
+    # That part was added by
+    # https://github.com/rear/rear/commit/e822ad69a8ce8dec6132741806008db9c6c3b429
+    # but there is no comment that explains why LUN WWIDs migration happens
+    # only if also $CONFIG_DIR/disklayout.conf exists.
+    if test -e $CONFIG_DIR/lun_wwid_mapping.conf ; then
         cp $CONFIG_DIR/lun_wwid_mapping.conf $LUN_WWID_MAP
-        LogPrint "$CONFIG_DIR/lun_wwid_mapping.conf exists, creating lun_wwid_mapping"
+        LogPrint "Will migrate LUN WWIDs after backup restore ($CONFIG_DIR/lun_wwid_mapping.conf exists)"
     fi
 fi
 
-if [ ! -e $LAYOUT_FILE ] ; then
-    Log "Disklayout file does not exist, creating empty file."
+if ! test -e $LAYOUT_FILE ; then
+    # TODO: This script layout/prepare/default/010_prepare_files.sh is only run during "rear recover"
+    # and I <jsmeix@suse.de> wonder if "rear recover" can work at all without a disklayout.conf file?
+    LogPrint "$LAYOUT_FILE file does not exist, creating empty file"
     : > $LAYOUT_FILE
 fi
 
-if [ -e $FS_UUID_MAP ] ; then
-    rm -f $FS_UUID_MAP  # Make sure old data is deleted.
-fi
-
+# Make sure old data is deleted:
+test -e $FS_UUID_MAP && rm -f $FS_UUID_MAP
 : > $LAYOUT_TODO
 : > $LAYOUT_DEPS
+

usr/share/rear/layout/save/GNU/Linux/100_create_layout_file.sh

@@ -1,23 +1,39 @@
 # Create the layout file
 
 LogPrint "Creating disk layout"
-Log "Preparing layout directory."
-mkdir -p $v $VAR_DIR/layout >&2
-mkdir -p $v $VAR_DIR/recovery >&2
-mkdir -p $v $VAR_DIR/layout/config >&2
 
-# We need directory for XFS options only if XFS is in use
-if [ -n "$(mount -t xfs)" ]; then
+Log "Creating layout directories (when not existing)"
+mkdir -p $v $VAR_DIR/layout
+mkdir -p $v $VAR_DIR/recovery
+mkdir -p $v $VAR_DIR/layout/config
+
+# We need directory for XFS options only if XFS is in use:
+if test "$( mount -t xfs )" ; then
     LAYOUT_XFS_OPT_DIR="$VAR_DIR/layout/xfs"
-    mkdir -p $v $LAYOUT_XFS_OPT_DIR >&2
+    mkdir -p $v $LAYOUT_XFS_OPT_DIR
 fi
 
-DISKLAYOUT_FILE=${DISKLAYOUT_FILE:-$VAR_DIR/layout/disklayout.conf}
+# Use exiting DISKLAYOUT_FILE value or use the default:
+test "$DISKLAYOUT_FILE" || DISKLAYOUT_FILE=$VAR_DIR/layout/disklayout.conf
 
-if [ -e "$DISKLAYOUT_FILE" ] ; then
-    Log "Removing old layout file."
-fi
-: > $DISKLAYOUT_FILE
+# Inform the user (he may have specified his DISKLAYOUT_FILE value, see above):
+test -e "$DISKLAYOUT_FILE" && LogPrint "Overwriting existing disk layout file $DISKLAYOUT_FILE"
+
+# Initialize disklayout.conf:
+# See lib/layout-functions.sh how DATE is set: DATE=$( date +%Y%m%d%H%M%S )
+echo "Disk layout dated $DATE (YYYYmmddHHMMSS)" >$DISKLAYOUT_FILE
+# Have the actual storage layout as header comment in disklayout.conf
+# so that it is easier to make sense of the values in the subsequent entries.
+# First try the command
+#   lsblk -ipo NAME,KNAME,PKNAME,TRAN,TYPE,FSTYPE,SIZE,MOUNTPOINT
+# but on older systems (like SLES11) that do not support all that lsblk things
+# try the simpler command
+#   lsblk -io NAME,KNAME,FSTYPE,SIZE,MOUNTPOINT
+# and as fallback try 'lsblk -i' and finally try plain 'lsblk'.
+# When there is no 'lsblk' command there is no output (bad luck, no harm):
+{ lsblk -ipo NAME,KNAME,PKNAME,TRAN,TYPE,FSTYPE,SIZE,MOUNTPOINT || lsblk -io NAME,KNAME,FSTYPE,SIZE,MOUNTPOINT || lsblk -i || lsblk ; } >>$DISKLAYOUT_FILE
+# Make all lines in disklayout.conf up to now as header comments:
+sed -i -e 's/^/# /' $DISKLAYOUT_FILE
 
 LAYOUT_FILE="$DISKLAYOUT_FILE"
 LAYOUT_DEPS="$VAR_DIR/layout/diskdeps.conf"
@@ -30,3 +46,4 @@ LAYOUT_TODO="$VAR_DIR/layout/disktodo.conf"
 # $LAYOUT_TODO is a list of:
 # [todo|done] <type> <item>
 : > $LAYOUT_TODO
+

usr/share/rear/lib/layout-functions.sh

@@ -693,7 +693,16 @@ is_disk_a_pv() {
 }
 
 function is_multipath_path {
-    [ "$1" ] && type multipath &>/dev/null && multipath -c /dev/$1 &>/dev/null
+    # Return 'false' if there is no device as argument:
+    test "$1" || return 1
+    # Return 'false' if there is no multipath command:
+    type multipath &>/dev/null || return 1
+    # Return 'false' if multipath is not used.
+    # Because "multipath -l" always returns zero exit code we check if it has real output
+    # and we do this via "grep -q" so that no "multipath -l" output appears in the log:
+    multipath -l | grep -q '[[:alnum:]]' || return 1
+    # Check if a block device should be a path in a multipath device:
+    multipath -c /dev/$1 &>/dev/null
 }
 
 # retry_command () is binded with REAR_SLEEP_DELAY and REAR_MAX_RETRIES.