NFSv4: parse and display server implementation ids

Shows the implementation ids in /proc/self/mountstats.  This doesn't break
the nfs-utils mountstats tool.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 20c3bb06763a..90a17cc3ebc9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4950,11 +4950,24 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
                 goto out;
         }
 
+        res.impl_id = kzalloc(sizeof(struct nfs41_impl_id), GFP_KERNEL);
+        if (unlikely(!res.impl_id)) {
+                status = -ENOMEM;
+                goto out_server_scope;
+        }
+
         status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
         if (!status)
                 status = nfs4_check_cl_exchange_flags(clp->cl_exchange_flags);
 
         if (!status) {
+                /* use the most recent implementation id */
+                kfree(clp->impl_id);
+                clp->impl_id = res.impl_id;
+        } else
+                kfree(res.impl_id);
+
+        if (!status) {
                 if (clp->server_scope &&
                     !nfs41_same_server_scope(clp->server_scope,
                                              res.server_scope)) {
@@ -4970,8 +4983,16 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
                         goto out;
                 }
         }
+
+out_server_scope:
         kfree(res.server_scope);
 out:
+        if (clp->impl_id)
+                dprintk("%s: Server Implementation ID: "
+                        "domain: %s, name: %s, date: %llu,%u\n",
+                        __func__, clp->impl_id->domain, clp->impl_id->name,
+                        clp->impl_id->date.seconds,
+                        clp->impl_id->date.nseconds);
         dprintk("<-- %s status= %d\n", __func__, status);
         return status;
 }