NFS associate sessionid with callback connection

The sessions based callback service is started prior to the CREATE_SESSION call
so that it can handle CB_NULL requests which can be sent before the
CREATE_SESSION call returns and the session ID is known.

Set the callback sessionid after a sucessful CREATE_SESSION.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/callback.c

@@ -136,6 +136,33 @@ nfs4_callback_up(struct svc_serv *serv)
 }
 
 #if defined(CONFIG_NFS_V4_1)
+/*
+ *  * CB_SEQUENCE operations will fail until the callback sessionid is set.
+ *   */
+int nfs4_set_callback_sessionid(struct nfs_client *clp)
+{
+	struct svc_serv *serv = clp->cl_rpcclient->cl_xprt->bc_serv;
+	struct nfs4_sessionid *bc_sid;
+
+	if (!serv->bc_xprt)
+		return -EINVAL;
+
+	/* on success freed in xprt_free */
+	bc_sid = kmalloc(sizeof(struct nfs4_sessionid), GFP_KERNEL);
+	if (!bc_sid)
+		return -ENOMEM;
+	memcpy(bc_sid->data, &clp->cl_session->sess_id.data,
+		NFS4_MAX_SESSIONID_LEN);
+	spin_lock_bh(&serv->sv_cb_lock);
+	serv->bc_xprt->xpt_bc_sid = bc_sid;
+	spin_unlock_bh(&serv->sv_cb_lock);
+	dprintk("%s set xpt_bc_sid=%u:%u:%u:%u for bc_xprt %p\n", __func__,
+		((u32 *)bc_sid->data)[0], ((u32 *)bc_sid->data)[1],
+		((u32 *)bc_sid->data)[2], ((u32 *)bc_sid->data)[3],
+		serv->bc_xprt);
+	return 0;
+}
+
 /*
  * The callback service for NFSv4.1 callbacks
  */
@@ -241,6 +268,10 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 		struct nfs_callback_data *cb_info)
 {
 }
+int nfs4_set_callback_sessionid(struct nfs_client *clp)
+{
+	return 0;
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 /*

fs/nfs/callback.h

@@ -137,6 +137,7 @@ extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
 extern void nfs_callback_down(int minorversion);
 extern int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation,
 					    const nfs4_stateid *stateid);
+extern int nfs4_set_callback_sessionid(struct nfs_client *clp);
 #endif /* CONFIG_NFS_V4 */
 /*
  * nfs41: Callbacks are expected to not cause substantial latency,

fs/nfs/nfs4state.c

@@ -192,6 +192,12 @@ int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 	status = nfs4_proc_create_session(clp);
 	if (status != 0)
 		goto out;
+	status = nfs4_set_callback_sessionid(clp);
+	if (status != 0) {
+		printk(KERN_WARNING "Sessionid not set. No callback service\n");
+		nfs_callback_down(1);
+		status = 0;
+	}
 	nfs41_setup_state_renewal(clp);
 	nfs_mark_client_ready(clp, NFS_CS_READY);
 out:

include/linux/sunrpc/svc_xprt.h

@@ -78,6 +78,7 @@ struct svc_xprt {
 	size_t			xpt_remotelen;	/* length of address */
 	struct rpc_wait_queue	xpt_bc_pending;	/* backchannel wait queue */
 	struct list_head	xpt_users;	/* callbacks on free */
+	void			*xpt_bc_sid;	/* back channel session ID */
 
 	struct net		*xpt_net;
 };

net/sunrpc/svcsock.c

@@ -1605,7 +1605,9 @@ static struct svc_xprt *svc_bc_create_socket(struct svc_serv *serv,
  */
 static void svc_bc_sock_free(struct svc_xprt *xprt)
 {
-	if (xprt)
+	if (xprt) {
+		kfree(xprt->xpt_bc_sid);
 		kfree(container_of(xprt, struct svc_sock, sk_xprt));
+	}
 }
 #endif /* CONFIG_NFS_V4_1 */