This reverts 17f4e6febca160a9f9dd4bdece9784577a2f4524 commit.

 Currently rpc_mkdir/rpc_rmdir and rpc_mkpipe/mk_unlink have an API that's
 a little unfortunate.  They take a path relative to the rpc_pipefs root and
 thus need to perform a full lookup.  If you look at debugfs or usbfs they
 always store the dentry for directories they created and thus can pass in
 a dentry + single pathname component pair into their equivalents of the
 above functions.

 And in fact rpc_pipefs actually stores a dentry for all but one component so
 this change not only simplifies the core rpc_pipe code but also the callers.

 Unfortuntately this code path is only used by the NFS4 idmapper and
 AUTH_GSSAPI for which I don't have a test enviroment.  Could someone give
 it a spin?  It's the last bit needed before we can rework the
 lookup_hash API
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Acked-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Ensure that we don't create an RPC client without checking that the server
 does indeed support the RPC program + version that we are trying to set up.

 This enables us to immediately return an error to "mount" if it turns out
 that the server is only supporting NFSv2, when we requested NFSv3 or NFSv4.
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!