If the expiring_list is empty, we can avoid a costly spinlock in the
rcu-walk path through autofs4_d_manage (once the rest of the path
becomes rcu-walk friendly).
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>