Fix handling of full not succeeding and wrong path

btrfs/subvolume-delta

@@ -10,9 +10,9 @@
 CDATE="$(date '+%s')"
 SNAPSRC="$SRC"
 SNAPPATH="$SNAPSRC/$SNAPDIR"
-PREV="$SRC/prev"
-CUR="$SRC/cur"
-TMP="$SRC/tmp"
+PREV="$SNAPPATH/prev"
+CUR="$SNAPPATH/cur"
+TMP="$SNAPPATH/tmp"
 SNAPDEST="$SNAPPATH/$CDATE"
 
 msg() {
@@ -45,7 +45,7 @@ symdel "$PREV"
 ln -sv "$CDATE" "$TMP" >&2
 btrfs subvolume snapshot -r "$SNAPSRC" "$SNAPDEST" >&2
 
-delta || full
+delta || full || return 1
 
 # Mark snapshot transmission as complete
 [ -L "$CUR" ] && \