nfsd4: lookup up callback cred only once

[safe/jmp/linux-2.6] / fs / nfsd / nfs4callback.c

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 3fd7136..cc10ed3 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -358,19 +358,21 @@ static struct rpc_program cb_program = {
                .pipe_dir_name  = "/nfsd4_cb",
 };
 
+static int max_cb_time(void)
+{
+       return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
+}
+
 /* Reference counting, callback cleanup, etc., all look racy as heck.
  * And why is cb_set an atomic? */
 
-static int do_probe_callback(void *data)
+int setup_callback_client(struct nfs4_client *clp)
 {
-       struct nfs4_client *clp = data;
        struct sockaddr_in      addr;
        struct nfs4_callback    *cb = &clp->cl_callback;
        struct rpc_timeout      timeparms = {
-               .to_initval     = (NFSD_LEASE_TIME/4) * HZ,
-               .to_retries     = 5,
-               .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
-               .to_exponential = 1,
+               .to_initval     = max_cb_time(),
+               .to_retries     = 0,
        };
        struct rpc_create_args args = {
                .protocol       = IPPROTO_TCP,
@@ -384,17 +386,10 @@ static int do_probe_callback(void *data)
                .flags          = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
                .client_name    = clp->cl_principal,
        };
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
-               .rpc_argp       = clp,
-       };
        struct rpc_clnt *client;
-       int status;
 
-       if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) {
-               status = nfserr_cb_path_down;
-               goto out_err;
-       }
+       if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
+               return -EINVAL;
 
        /* Initialize address */
        memset(&addr, 0, sizeof(addr));
@@ -405,27 +400,64 @@ static int do_probe_callback(void *data)
        /* Create RPC client */
        client = rpc_create(&args);
        if (IS_ERR(client)) {
-               dprintk("NFSD: couldn't create callback client\n");
-               status = PTR_ERR(client);
-               goto out_err;
+               dprintk("NFSD: couldn't create callback client: %ld\n",
+                       PTR_ERR(client));
+               return PTR_ERR(client);
        }
+       cb->cb_client = client;
+       return 0;
+
+}
 
-       status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
+static void warn_no_callback_path(struct nfs4_client *clp, int reason)
+{
+       dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
+               (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;
+       struct nfs4_callback    *cb = &clp->cl_callback;
+       struct rpc_message msg = {
+               .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)
-               goto out_release_client;
+               warn_no_callback_path(clp, status);
+       else
+               atomic_set(&cb->cb_set, 1);
 
-       cb->cb_client = client;
-       atomic_set(&cb->cb_set, 1);
        put_nfs4_client(clp);
        return 0;
-out_release_client:
-       rpc_shutdown_client(client);
-out_err:
-       dprintk("NFSD: warning: no callback path to client %.*s\n",
-               (int)clp->cl_name.len, clp->cl_name.data);
-       put_nfs4_client(clp);
-       return status;
 }
 
 /*
@@ -435,9 +467,16 @@ void
 nfsd4_probe_callback(struct nfs4_client *clp)
 {
        struct task_struct *t;
+       int status;
 
        BUG_ON(atomic_read(&clp->cl_callback.cb_set));
 
+       status = setup_callback_client(clp);
+       if (status) {
+               warn_no_callback_path(clp, status);
+               return;
+       }
+
        /* the task holds a reference to the nfs4_client struct */
        atomic_inc(&clp->cl_count);
 
@@ -461,6 +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;
@@ -491,8 +531,6 @@ out_put_cred:
         * or deleg_return.
         */
        put_nfs4_client(clp);
-       nfs4_lock_state();
        nfs4_put_delegation(dp);
-       nfs4_unlock_state();
        return;
 }