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-rw-r--r--fs/nfs/nfs4renewd.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
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+++ b/fs/nfs/nfs4renewd.c
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+/*
+ * 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:
+ */