Comment 39 for bug 554737

As for why /forcefsck is not removed:

that file is not removed by fsck, instead the mountall init script contains:

post-stop script
    rm -f /forcefsck 2>dev/null || true
end script

which will delete the file after all checks have been done and all filesystems are mounted. So unless mountall stops fine, /forcefsck will not be removed. And as the moment when this happens is only defined as "after mountall finishes", this might be after login too.