=head1 NAME

aa-stage4 - Stage 4: Unmounting root file system

=head1 SYNOPSIS

B<aa-stage4>

=head1 DESCRIPTION

B<aa-stage4>(1) is an B<execline> script meant to be used as I<shutdown> inside
an initramfs.

It loads the environment from I</etc/anopa/env> (via B<s6-envdir>).

It doesn't do much in itself, the bulk of the work being done via services, much
like during system shutdown (stage 3). It will simply call B<aa-stop>(1) using
I</servives> as repodir, with option B<--all>.

Services are meant to unmount the root file system from I</root-fs> as well as
all API file systems in there: I</root-fs/dev>, I</root-fs/proc>,
I</root-fs/sys> and I</root-fs/run>

After B<aa-stop>(1) has run, and if it exists, B<aa-stage4>(1) will execute
I</services/.anopa/post-stop> with B<aa-stop>(1)'s return code as
argument. This allows to e.g. open a shell if something went terribly wrong.

Note that obviously by this point there's no more logger, and unlike at other
stages file descriptor 3 isn't open anymore.

Then it will mount I</dev> and I</proc> in order to run B<aa-terminate>(1) to
make sure everything is closed/unmounted. If B<aa-terminate>(1) exits non-zero,
an interactive shell (I<sh -i>) is opened.

It then performs the requested action (on stage 3) via B<aa-reboot>(1).