add a clientid mount option

[Christoph Hellwig <hch@xxxxxx>]

Hi all,

this series adds a new clientid mount option that allows to use a
non-default clientid on a per-mount basis to make it easy to test
client-based behavior on a single client system.

Diffstat:
 fs/nfs/client.c           |   12 +++
 fs/nfs/fs_context.c       |   12 +++
 fs/nfs/internal.h         |    2 
 fs/nfs/nfs4client.c       |  152 ++++++++++++++++++++--------------------------
 fs/nfs/nfs4proc.c         |    7 +-
 include/linux/nfs_fs_sb.h |    1 
 6 files changed, 102 insertions(+), 84 deletions(-)