[GIT PULL] namespace related fixes for 4.10-rc3

[Al Viro]

On Sat, Jan 07, 2017 at 06:29:52AM +0000, Al Viro wrote:
> On Sat, Jan 07, 2017 at 06:30:05PM +1300, Eric W. Biederman wrote:
> 
> > Eric W. Biederman (3):
> >       mnt: Protect the mountpoint hashtable with mount_lock
> ACK
> 
> >       mnt: Tuck mounts under others instead of creating shadow/side mounts.
> 
> NAK; you have reintroduced put_mountpoint() outside of mount lock in there
> and you've got seriously confused umount side of the things.

PS: details are in my reply (admittedly, sent only ~20 minutes
before your pull request) to your patch.  Check Message-ID
<20170107050644.GA12074 at ZenIV.linux.org.uk>

My apologies for not getting to it yesterday (the patch was posted a couple of
days ago, AFAICS) - I'd been off-net since Wednesday, just got back ;-/