1 files changed, 143 insertions, 0 deletions
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
new file mode 100644
index 000000000..e1ba58c3d
--- /dev/null
+++ b/fs/nfs/nfs4renewd.c
@@ -0,0 +1,143 @@
+/*
+ *  fs/nfs/nfs4renewd.c
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Implementation of the NFSv4 "renew daemon", which wakes up periodically to
+ * send a RENEW, to keep state alive on the server.  The daemon is implemented
+ * as an rpc_task, not a real kernel thread, so it always runs in rpciod's
+ * context.  There is one renewd per nfs_server.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/clnt.h>
+
+#include <linux/nfs.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "delegation.h"
+
+#define NFSDBG_FACILITY		NFSDBG_STATE
+
+void
+nfs4_renew_state(struct work_struct *work)
+{
+	const struct nfs4_state_maintenance_ops *ops;
+	struct nfs_client *clp =
+		container_of(work, struct nfs_client, cl_renewd.work);
+	struct rpc_cred *cred;
+	long lease;
+	unsigned long last, now;
+	unsigned renew_flags = 0;
+
+	ops = clp->cl_mvops->state_renewal_ops;
+	dprintk("%s: start\n", __func__);
+
+	if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
+		goto out;
+
+	spin_lock(&clp->cl_lock);
+	lease = clp->cl_lease_time;
+	last = clp->cl_last_renewal;
+	now = jiffies;
+	/* Are we close to a lease timeout? */
+	if (time_after(now, last + lease/3))
+		renew_flags |= NFS4_RENEW_TIMEOUT;
+	if (nfs_delegations_present(clp))
+		renew_flags |= NFS4_RENEW_DELEGATION_CB;
+
+	if (renew_flags != 0) {
+		cred = ops->get_state_renewal_cred_locked(clp);
+		spin_unlock(&clp->cl_lock);
+		if (cred == NULL) {
+			if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
+				set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+				goto out;
+			}
+			nfs_expire_all_delegations(clp);
+		} else {
+			int ret;
+
+			/* Queue an asynchronous RENEW. */
+			ret = ops->sched_state_renewal(clp, cred, renew_flags);
+			put_rpccred(cred);
+			switch (ret) {
+			default:
+				goto out_exp;
+			case -EAGAIN:
+			case -ENOMEM:
+				break;
+			}
+		}
+	} else {
+		dprintk("%s: failed to call renewd. Reason: lease not expired \n",
+				__func__);
+		spin_unlock(&clp->cl_lock);
+	}
+	nfs4_schedule_state_renewal(clp);
+out_exp:
+	nfs_expire_unreferenced_delegations(clp);
+out:
+	dprintk("%s: done\n", __func__);
+}
+
+void
+nfs4_schedule_state_renewal(struct nfs_client *clp)
+{
+	long timeout;
+
+	spin_lock(&clp->cl_lock);
+	timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
+		- (long)jiffies;
+	if (timeout < 5 * HZ)
+		timeout = 5 * HZ;
+	dprintk("%s: requeueing work. Lease period = %ld\n",
+			__func__, (timeout + HZ - 1) / HZ);
+	mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
+	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
+	spin_unlock(&clp->cl_lock);
+}
+
+void
+nfs4_kill_renewd(struct nfs_client *clp)
+{
+	cancel_delayed_work_sync(&clp->cl_renewd);
+}
+
+/*
+ * Local variables:
+ *   c-basic-offset: 8
+ * End:
+ */