Add a per-superblock performance counter facility to the NFS client.  This
facility mimics the counters available for block devices and for
networking.  Expose these new counters via the new /proc/self/mountstats
interface.

Thanks to Andrew Morton and Trond Myklebust for their review and comments.

Test plan:
fsx and iozone on UP and SMP systems, with and without pre-emption.  Watch
for memory overwrite bugs, and performance loss (significantly more CPU
required per op).
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Sometimes it's important to know the exact RPC retransmit settings the
kernel is using for an NFS mount point.  Add this facility to the NFS
client's show_options method.

Test plan:
Set various retransmit settings via the mount command, and check that the
settings are reflected in /proc/mounts.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 This adds acl support fo nfs clients via the NFSACL protocol extension, by
 implementing the getxattr, listxattr, setxattr, and removexattr iops for the
 system.posix_acl_access and system.posix_acl_default attributes.  This patch
 implements a dumb version that uses no caching (and thus adds some overhead).
 (Another patch in this patchset adds caching as well.)
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Acked-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!