Make two custom mounts with nested source directories illegal.

diff --git a/scripts/live-helpers b/scripts/live-helpers
index 75fc106..52f812c 100644 (file)
--- a/scripts/live-helpers
+++ b/scripts/live-helpers
@@ -1342,7 +1342,24 @@ get_custom_mounts ()
 
        # After all mounts are considered we add symlinks so they
        # won't be hidden by some mount.
-       [ -e "${links}" ] && sort -k3 -sbu ${links} >> ${custom_mounts} && rm ${links}
+       [ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
+
+       # We need to make sure that no two custom mounts have the same sources
+       # or are nested; if that is the case, too much weird stuff can happen.
+       local prev_source="impossible source" # first iteration must not match
+       local prev_dest=""
+       # This sort will ensure that a source /a comes right before a source
+       # /a/b so we only need to look at the previous source
+       sort -k2 -b ${custom_mounts} |
+       while read device source dest options
+       do
+               if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
+               then
+                       panic "Two persistent mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
+               fi
+               prev_source=${source}
+               prev_dest=${dest}
+       done
 }
 
 activate_custom_mounts ()
@@ -1356,7 +1373,7 @@ activate_custom_mounts ()
                local opt_union=""
                for opt in $(echo ${options} | tr ',' ' ');
                do
-                        case "${opt}" in
+                       case "${opt}" in
                                linkfiles)
                                        opt_linkfiles="yes"
                                        ;;