LU-1187 lmv: Locate right MDT in lmv.

1.Add fid in md_revalidate_lock for locate mdt in
do_statahead_interpret.
2.locate right mdc for FID2PATH.
3.Only validating MDT0 connection for statfsi during Mount,
so even some MDTs are not avaible, the system can still be
setup.

Signed-off-by: Wang Di <di.wang@intel.com>
Change-Id: I40a3dcbe1f87cd38386ea360547dd2b4528645d1
Reviewed-on: http://review.whamcloud.com/4356
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
LU-1187 dne: add remote dir check in replay-vbr.

Add remote dir check in replay-vbr.

Change-Id: Ia955703a45c1fe63439d0cbe893b73bb12a77305
Signed-off-by: Wang Di <di.wang@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/4321
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
LU-1187 tests: Add mntfmt/mntcount/mdtcount to mdsrate

Add mntfmt, mntcount and mdtcount to parameters of mdsrate, so
it can do multiple mount or DNE tests.

Signed-off-by: wang di <di.wang@whamcloud.com>
Change-Id: Ie3859ab13ef1ed680e645883611c5f8c9ea4e4a5
Reviewed-on: http://review.whamcloud.com/4614
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>