From 9ea459e110df32e60a762f311f7939eaa879601d Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 8 Aug 2014 13:08:20 -0400
Subject: [PATCH] delayed mntput

On final mntput() we want fs shutdown to happen before return to
userland; however, the only case where we want it happen right
there (i.e. where task_work_add won't do) is MNT_INTERNAL victim.
Those have to be fully synchronous - failure halfway through module
init might count on having vfsmount killed right there.  Fortunately,
final mntput on MNT_INTERNAL vfsmounts happens on shallow stack.
So we handle those synchronously and do an analog of delayed fput
logics for everything else.

As the result, we are guaranteed that fs shutdown will always happen
on shallow stack.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
Reading git-format-patch failed