tree 55d3c1b4a992afc33c28b5d1d4e37943de4b1389
parent 1a80810fbf238e6dbaaaa5262a76d328ace21376
author NeilBrown <neilb@suse.com> 1543797030 +1100
committer Anna Schumaker <Anna.Schumaker@Netapp.com> 1545245565 -0500

NFSv4: add cl_root_cred for use when machine cred is not available.

NFSv4 state management tries a root credential when no machine
credential is available, as can happen with kerberos.
It does this by replacing the cl_machine_cred with a root credential.
This means that any user of the machine credential needs to take
a lock while getting a reference to the machine credential, which is
a little cumbersome.

So introduce an explicit cl_root_cred, and never free either
credential until client shutdown.  This means that no locking
is needed to reference these credentials.  Future patches
will make use of this.

This is only a temporary addition.  both cl_machine_cred and
cl_root_cred will disappear later in the series.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>