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>
This commit is contained in:
NeilBrown
2018-12-03 11:30:30 +11:00
committed by Anna Schumaker
parent 1a80810fbf
commit a534ecb013
3 changed files with 15 additions and 8 deletions

View File

@@ -59,6 +59,7 @@ struct nfs_client {
u32 cl_minorversion;/* NFSv4 minorversion */
struct rpc_cred *cl_machine_cred;
struct rpc_cred *cl_root_cred; /* Use when machine_cred is ineffective */
#if IS_ENABLED(CONFIG_NFS_V4)
struct list_head cl_ds_clients; /* auth flavor data servers */