/etc/mtab is now a true reflection on /proc/mounts. The only exception is that we punt any / on tmpfs entry, #194615.

ChangeLog

@@ -3,6 +3,9 @@
 
   29 Oct 2007; Roy Marples <uberlord@gentoo.org>:
 
+    /etc/mtab is now a true reflection on /proc/mounts.
+    The only exception is that we punt any / on tmpfs entry, #194615.
+
     Network config arrays are now split by embedded new lines instead of
     being evaled into space separated values. This makes it easier to read,
     maintain and document as discussed on gentoo-dev.

init.d/checkroot

@@ -13,19 +13,11 @@ do_mtab() {
 	fi
 	ebegin "Updating /etc/mtab"
 
-	# Add the entry for / to mtab
-	mount -f /
-
-	# Don't list root more than once
-	grep -v "^[^ ]* / " /proc/mounts >> /etc/mtab
-
-	# Now make sure /etc/mtab have additional info (gid, etc) in there
-	local mnt=
-	mountinfo | while read mnt; do
-		if fstabinfo --quiet "${mnt}"; then
-			mount -f -o remount "${mnt}"
-		fi
-	done
+	# With / as tmpfs we cannot umount -at tmpfs in localmount as that
+	# makes / readonly and dismounts all tmpfs even if in use which is
+	# not good. Luckily, umount uses /etc/mtab instead of /proc/mounts
+	# which allows this hack to work.
+	grep -v "^[^ ]* / tmpfs" /proc/mounts > /etc/mtab
 
 	# Remove stale backups
 	rm -f /etc/mtab~ /etc/mtab~~