+ * TODO: cb_sequence should support referring call lists, cachethis, multiple
+ * slots, and mark callback channel down on communication errors.
+ */
+static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+ struct nfs4_rpc_args *args = task->tk_msg.rpc_argp;
+ u32 minorversion = clp->cl_cb_conn.cb_minorversion;
+ int status = 0;
+
+ args->args_seq.cbs_minorversion = minorversion;
+ if (minorversion) {
+ status = nfsd41_cb_setup_sequence(clp, task);
+ if (status) {
+ if (status != -EAGAIN) {
+ /* terminate rpc task */
+ task->tk_status = status;
+ task->tk_action = NULL;
+ }
+ return;
+ }
+ }
+ rpc_call_start(task);
+}
+
+static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+
+ dprintk("%s: minorversion=%d\n", __func__,
+ clp->cl_cb_conn.cb_minorversion);
+
+ if (clp->cl_cb_conn.cb_minorversion) {
+ /* No need for lock, access serialized in nfsd4_cb_prepare */
+ ++clp->cl_cb_seq_nr;
+ clear_bit(0, &clp->cl_cb_slot_busy);
+ rpc_wake_up_next(&clp->cl_cb_waitq);
+ dprintk("%s: freed slot, new seqid=%d\n", __func__,
+ clp->cl_cb_seq_nr);
+
+ /* We're done looking into the sequence information */
+ task->tk_msg.rpc_resp = NULL;
+ }
+}
+
+static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+
+ nfsd4_cb_done(task, calldata);
+
+ switch (task->tk_status) {
+ case -EIO:
+ /* Network partition? */
+ atomic_set(&clp->cl_cb_conn.cb_set, 0);
+ warn_no_callback_path(clp, task->tk_status);
+ case -EBADHANDLE:
+ case -NFS4ERR_BAD_STATEID:
+ /* Race: client probably got cb_recall
+ * before open reply granting delegation */
+ break;
+ default:
+ /* success, or error we can't handle */
+ goto done;
+ }
+ if (dp->dl_retries--) {
+ rpc_delay(task, 2*HZ);
+ task->tk_status = 0;
+ rpc_restart_call(task);
+ return;
+ } else {
+ atomic_set(&clp->cl_cb_conn.cb_set, 0);
+ warn_no_callback_path(clp, task->tk_status);
+ }
+done:
+ kfree(task->tk_msg.rpc_argp);
+}
+
+static void nfsd4_cb_recall_release(void *calldata)
+{
+ struct nfs4_delegation *dp = calldata;
+ struct nfs4_client *clp = dp->dl_client;
+
+ nfs4_put_delegation(dp);
+ put_nfs4_client(clp);
+}
+
+static const struct rpc_call_ops nfsd4_cb_recall_ops = {
+ .rpc_call_prepare = nfsd4_cb_prepare,
+ .rpc_call_done = nfsd4_cb_recall_done,
+ .rpc_release = nfsd4_cb_recall_release,
+};
+
+/*