How to disable tmpfs on /run/shm in proper way

Question

How to disable tmpfs on /run/shm ?

I searched through initscripts and found that the following code checks the entry in fstab, but what i should to place to fstab to not mount /run/shm ? my distro is debian/sid.

file /lib/init/mount-functions.sh

read_fstab_entry () {
        # Not found by default.
        found=1

        for file in "$(eval ls $(fstab_files))"; do
                if [ -f "$file" ]; then
                        while read MNT_FSNAME MNT_DIR MNT_TYPE MNT_OPTS MNT_FREQ MNT_PASS MNT_JUNK; do
                                case "$MNT_FSNAME" in
                                  ""|\#*)
                                        continue;
                                        ;;
                                esac
                                if [ "$MNT_DIR" = "$1" ]; then
                                        if [ -n "$2" ]; then
                                                [ "$MNT_TYPE" = "$2" ] || continue;
                                        fi
                                        found=0
                                        break 2
                                fi
                        done < "$file"
                fi
        done

        return $found

that function called in same script here:

 if read_fstab_entry /run/lock; then
            if [ "$MNT_TYPE" = "tmpfs" ] ; then
                RAMLOCK="yes"
            else
                RAMLOCK="no"
            fi
        fi

<---CUT---->

if [ yes = "$RAMLOCK" ]; then
                domount "$MNTMODE" tmpfs shmfs /run/lock tmpfs "-o${NODEV}noexec,nosuid$LOCK_OPT"
                # Make sure we don't get cleaned
                touch /run/lock/.tmpfs
        else
                chmod "$LOCK_MODE" /run/lock
        fi

Answer 1

It's not clear what you're trying to achieve. By default (at least on Debian wheezy), /run/shm is a subdirectory of /run, which is mounted as tmpfs. So if you don't want /run/shm to be a mount point, don't change the default configuration. If you create an entry for /run/shm in /etc/fstab, it will be mounted only if you specify the filesystem type; otherwise /dev/shm is bind-mounted there. Not having /run/shm as tmpfs is not a supported configuration. If you want to use some other filesystem type, create an fstab entry and edit /etc/init.d/mountall.sh and /etc/init.d/mountdevsubfs.sh so that they call mount_shm with an argument other than mount or mount_update. Whatever you do, make sure that /run/shm is mode 1777 and has no files left over from a previous boot.

Answer 2

Put "#" in front of the fstab-Entry, to mark is as comment.

If you look at the script that will trigger the continue-branch within the case-statement making it skip that line.