nfsd4: lookup up callback cred only once

Lookup the callback cred once and then use it for all subsequent
callbacks.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

3 files changed, 31 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 711c6282151f..cc10ed35ac81 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -415,6 +415,22 @@ static void warn_no_callback_path(struct nfs4_client *clp, int reason)
                 (int)clp->cl_name.len, clp->cl_name.data, reason);
 }
 
+static struct rpc_cred *lookup_cb_cred(struct nfs4_callback *cb)
+{
+        struct auth_cred acred = {
+                .machine_cred = 1
+        };
+
+        /*
+         * Note in the gss case this doesn't actually have to wait for a
+         * gss upcall (or any calls to the client); this just creates a
+         * non-uptodate cred which the rpc state machine will fill in with
+         * a refresh_upcall later.
+         */
+        return rpcauth_lookup_credcache(cb->cb_client->cl_auth, &acred,
+                                                        RPCAUTH_LOOKUP_NEW);
+}
+
 static int do_probe_callback(void *data)
 {
         struct nfs4_client *clp = data;
@@ -423,9 +439,18 @@ static int do_probe_callback(void *data)
                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
                 .rpc_argp       = clp,
         };
+        struct rpc_cred *cred;
         int status;
 
+        cred = lookup_cb_cred(cb);
+        if (IS_ERR(cred)) {
+                status = PTR_ERR(cred);
+                goto out;
+        }
+        cb->cb_cred = cred;
+        msg.rpc_cred = cb->cb_cred;
         status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
+out:
         if (status)
                 warn_no_callback_path(clp, status);
         else
@@ -475,6 +500,7 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
         struct rpc_message msg = {
                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
                 .rpc_argp = cbr,
+                .rpc_cred = clp->cl_callback.cb_cred
         };
         int retries = 1;
         int status = 0;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 7e1fcc3aade4..b205c7d7bc6a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -643,6 +643,10 @@ shutdown_callback_client(struct nfs4_client *clp)
                 clp->cl_callback.cb_client = NULL;
                 rpc_shutdown_client(clnt);
         }
+        if (clp->cl_callback.cb_cred) {
+                put_rpccred(clp->cl_callback.cb_cred);
+                clp->cl_callback.cb_cred = NULL;
+        }
 }
 
 static inline void
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 4d61c873feed..8d882a3eb4b9 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -97,6 +97,7 @@ struct nfs4_callback {
         /* RPC client info */
         atomic_t                cb_set;     /* successful CB_NULL call */
         struct rpc_clnt *       cb_client;
+        struct rpc_cred *       cb_cred;
 };
 
 /* Maximum number of slots per session. 128 is useful for long haul TCP */