vfs.git for -rc3

Assorted fixes, with an unexpected detour into vfio refcounting logics (fell out when digging in an analog of eventpoll race in there). Please, pull from the usual place -
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git for-linus

Shortlog:
Al Viro (7):
mqueue: lift mnt_want_write() outside ->i_mutex, clean up a bit
vfio: don't dereference after kfree...
introduce kref_put_mutex()
vfio: get rid of open-coding kref_put_mutex
vfio: get rid of vfio_device_put()/vfio_group_get_device* races
vfio: grab vfio_device reference *before* exposing the sucker via fd_install()
eventpoll: use-after-possible-free in epoll_create1()

Eric Dumazet (1):
task_work: add a scheduling point in task_work_run()

Randy Dunlap (1):
fs: fix fs/namei.c kernel-doc warnings

Diffstat:

 drivers/vfio/vfio.c  |   19 +++++---------
 fs/eventpoll.c       |    2 +-
 fs/namei.c           |    2 +
 include/linux/kref.h |   18 ++++++++++++++
 ipc/mqueue.c         |   61 +++++++++++++++++++++++---------------------------
 kernel/task_work.c   |    1 +
 6 files changed, 57 insertions(+), 46 deletions(-)