98usrmount: force mounting /usr read-only option (rd.usrmount.ro)

dracut.cmdline.7.asc

@@ -76,6 +76,11 @@ resume=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
 ----
 
 
+**rd.usrmount.ro**:
+    force mounting _/usr_ read-only.  Use this option if your init system
+    performs remount of _/usr_ the same as it does with rootfs.
+
+
 Misc
 ~~~~
 **rd.driver.blacklist=**_<drivername>[,<drivername>,...]_::

modules.d/98usrmount/mount-usr.sh

@@ -68,10 +68,15 @@ mount_usr()
         _ret=$?
         echo $_ret >/run/initramfs/usr-fsck
         if [ $_ret -ne 255 ]; then
+            if getargbool 0 rd.usrmount.ro; then
+                info "Mounting /usr (read-only forced)"
+                mount -r "$NEWROOT/usr" 2>&1 | vinfo
+            else
                 info "Mounting /usr"
                 mount "$NEWROOT/usr" 2>&1 | vinfo
             fi
         fi
+    fi
 }
 
 if [ -f "$NEWROOT/etc/fstab" ]; then