tree 2769a42950ce9704f3a3c7b9fd9a61b4426d7d30
parent ed6473ddc704a2005b9900ca08e236ebb2d8540a
author J. Bruce Fields <bfields@redhat.com> 1490750708 -0400
committer J. Bruce Fields <bfields@redhat.com> 1494281178 -0400

lockd: fix lockd shutdown race

As reported by David Jeffery: "a signal was sent to lockd while lockd
was shutting down from a request to stop nfs.  The signal causes lockd
to call restart_grace() which puts the lockd_net structure on the grace
list.  If this signal is received at the wrong time, it will occur after
lockd_down_net() has called locks_end_grace() but before
lockd_down_net() stops the lockd thread.  This leads to lockd putting
the lockd_net structure back on the grace list, then exiting without
anything removing it from the list."

So, perform the final locks_end_grace() from the the lockd thread; this
ensures it's serialized with respect to restart_grace().

Reported-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>