Merge git://git.linux-nfs.org/pub/linux/nfs-2.6

Merge git://git.linux-nfs.org/pub/linux/nfs-2.6

* git://git.linux-nfs.org/pub/linux/nfs-2.6:
  NFS: Clean up new multi-segment direct I/O changes
  NFS: Ensure we return zero if applications attempt to write zero bytes
  NFS: Support multiple segment iovecs in the NFS direct I/O path
  NFS: Introduce iovec I/O helpers to fs/nfs/direct.c
  SUNRPC: Add missing "space" to net/sunrpc/auth_gss.c
  SUNRPC: make sunrpc/xprtsock.c:xs_setup_{udp,tcp}() static
  NFS: fs/nfs/dir.c should #include "internal.h"
  NFS: make nfs_wb_page_priority() static
  NFS: mount failure causes bad page state
  SUNRPC: remove NFS/RDMA client's binary sysctls
  kernel BUG at fs/nfs/namespace.c:108! - can be triggered by bad server
  sunrpc: rpc_pipe_poll may miss available data in some cases
  sunrpc: return error if unsupported enctype or cksumtype is encountered
  sunrpc: gss_pipe_downcall(), don't assume all errors are transient
  NFS: Fix the ustat() regression