[GIT PULL] namespace related fixes for 4.10-rc3

[Eric W. Biederman]

Linus,

Please pull the for-linus branch from the git tree:

   git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git for-linus

   HEAD: cd293bfacd57928627ef7da6194e0cbe24db3291 sysctl: Drop reference added by grab_header in proc_sys_readdir

This tree contains 5 fixes.

The first is a fix for a race that can causes oopses under the right
circumstances, and that someone just recently encountered.

The second is a fix that removes the possibility of creating unbounded
chains in the mount hash table.  After a lot of back and forth this fix
has finally matured into something mergeable.

Past that are several small trivial correct fixes.  A real issue that
was blocking development of an out of tree driver, but does not appear
to have caused any actual problems for in-tree code.  A potential
deadlock that was reported by lockdep.  And a deadlock people have
experienced and took the time to track down caused by a cleanup that
removed the code to drop a reference count.

Andrei Vagin (1):
      pid: fix lockdep deadlock warning due to ucount_lock

Eric W. Biederman (3):
      mnt: Protect the mountpoint hashtable with mount_lock
      mnt: Tuck mounts under others instead of creating shadow/side mounts.
      libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount

Zhou Chengming (1):
      sysctl: Drop reference added by grab_header in proc_sys_readdir

 fs/dcache.c            |   7 +-
 fs/libfs.c             |   3 +-
 fs/mount.h             |   1 -
 fs/namespace.c         | 174 +++++++++++++++++++++++++++++--------------------
 fs/pnode.c             |  27 ++++++--
 fs/pnode.h             |   2 +
 fs/proc/proc_sysctl.c  |   3 +-
 kernel/pid_namespace.c |  10 +--
 8 files changed, 142 insertions(+), 85 deletions(-)

Eric