Add support for persistence-storage type "directory".

This adds support for mounting a plain writable directory as the
persistence storage layer. The $PERSISTENCE_PATH and the persistence-label
are taken into account when searching for the persistence.conf file.

diff --git a/components/9990-misc-helpers.sh b/components/9990-misc-helpers.sh
index 2515ea1..2a3e6ad 100755 (executable)
--- a/components/9990-misc-helpers.sh
+++ b/components/9990-misc-helpers.sh
@@ -684,8 +684,9 @@ try_mount ()
 }
 
 # Try to mount $device to the place expected by live-boot. If $device
-# is already mounted somewhere, move it to the expected place. If
-# we're only probing $device (to check if it has custom persistence)
+# is already mounted somewhere, move it to the expected place. If $device
+# ends with a "/" this is a directory path.
+# If we're only probing $device (to check if it has custom persistence)
 # $probe should be set, which suppresses warnings upon failure. On
 # success, print the mount point for $device.
 mount_persistence_media ()
@@ -694,6 +695,15 @@ mount_persistence_media ()
        device=${1}
        probe=${2}
 
+       # get_custom_mounts() might call this with a directory path instead
+       # of a block device path. This means we have found sub-directory path
+       # underneath /lib/live/mounts/persistence, so we're done
+       if [ -d "${device}" ]
+       then
+               echo "${device}"
+               return 0
+       fi
+
        if [ ! -b "${device}" ]
        then
                return 1
@@ -908,6 +918,39 @@ probe_for_file_name ()
        fi
 }
 
+probe_for_directory_name ()
+{
+       local overlays dev ret backing
+       overlays="${1}"
+       dev="${2}"
+
+       ret=""
+       backing="$(mount_persistence_media ${dev} probe)"
+       if [ -z "${backing}" ]
+       then
+           return
+       fi
+
+       for label in ${overlays}
+       do
+               path=${backing}/${PERSISTENCE_PATH}/${label}
+               if [ -d "${path}" ]
+               then
+                       # in this case the "device" ends with a "/"
+                       ret="${ret} ${label}=${backing}/${PERSISTENCE_PATH}/${label%%/}/"
+               fi
+       done
+
+       if [ -n "${ret}" ]
+       then
+               echo ${ret}
+       else
+               # unmount and remove mountpoint
+               umount ${backing} > /dev/null 2>&1 || true
+               rmdir ${backing} > /dev/null 2>&1 || true
+       fi
+}
+
 find_persistence_media ()
 {
        # Scans devices for overlays, and returns a whitespace
@@ -1013,6 +1056,17 @@ find_persistence_media ()
                        fi
                fi
 
+               # Probe for directory with matching name on mounted partition
+               if is_in_comma_sep_list directory ${PERSISTENCE_STORAGE}
+               then
+                       result=$(probe_for_directory_name "${overlays}" ${dev})
+                       if [ -n "${result}" ]
+                       then
+                               ret="${ret} ${result}"
+                               continue
+                       fi
+               fi
+
                # Close luks device if it isn't used
                if [ -z "${result}" ] && [ -n "${luks_device}" ] && is_active_luks_mapping "${luks_device}"
                then