own mailserver, lots of improvements

[distro-setup] / mount-latest-subvol

diff --git a/mount-latest-subvol b/mount-latest-subvol
old mode 100755 (executable)
new mode 100644 (file)
index 091cf44..a8ff06d
--- a/mount-latest-subvol
+++ b/mount-latest-subvol
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
+# usage: mount-latest-subvol
 
 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
 
@@ -76,6 +76,7 @@ mnt() {
 
 ret=0
 
+##### begin setup fstab for subvols we care about ######
 first_root_crypt=$(awk '$2 == "/" {print $1}' /etc/mtab)
 tu /etc/fstab <<EOF
 $first_root_crypt  /a  btrfs  noatime,subvol=a  0 0
@@ -84,31 +85,37 @@ case $HOSTNAME in
     treetowl|x2|frodo)
         tu /etc/fstab <<EOF
 $first_root_crypt  /q  btrfs  noatime,subvol=q  0 0
+$first_root_crypt  /m  btrfs  noatime,subvol=m  0 0
 /q/p  /p  none  bind  0 0
 EOF
         ;;
 esac
+##### end setup fstab for subvols we care about ######
 
-for vol in q a; do
+for vol in q a m; do
     d=/$vol
     if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
         continue
     fi
 
 
-    binds=()
-    roots=($d)
+    ##### begin building up list of bind mounts  ######
+    binds=() # list of bind mounts
+    roots=($d) # list of bind mounts, plus the original mount
     while true; do
         new_roots=()
         for r in ${roots[@]}; do
-            # example
+            # eg. when r=/q/p, for lines like
             # /q/p  /p  none  bind  0 0
+            # output /p
             new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#p" /etc/fstab))
         done
         (( ${#new_roots} )) || break
         binds+=(${new_roots[@]})
         roots=( ${new_roots[@]} )
     done
+    ##### end building up list of bind mounts  ######
+
 
     # if latest is already mounted, make sure binds are mounted and move on
     if e check-subvol-stale $d; then