Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 148 insertions, 0 deletions

diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
new file mode 100644
index 000000000000..667e06f1c647
--- /dev/null
+++ b/fs/nfs/nfs4renewd.c
@@ -0,0 +1,148 @@
+/*
+ *  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.
+ *
+ * TODO: If the send queue gets backlogged (e.g., if the server goes down),
+ * we will keep filling the queue with periodic RENEW requests.  We need a
+ * mechanism for ensuring that if renewd successfully sends off a request,
+ * then it only wakes up when the request is finished.  Maybe use the
+ * child task framework of the RPC layer?
+ */
+
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#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>
+
+#define NFSDBG_FACILITY	NFSDBG_PROC
+
+void
+nfs4_renew_state(void *data)
+{
+	struct nfs4_client *clp = (struct nfs4_client *)data;
+	long lease, timeout;
+	unsigned long last, now;
+
+	down_read(&clp->cl_sem);
+	dprintk("%s: start\n", __FUNCTION__);
+	/* Are there any active superblocks? */
+	if (list_empty(&clp->cl_superblocks))
+		goto out; 
+	spin_lock(&clp->cl_lock);
+	lease = clp->cl_lease_time;
+	last = clp->cl_last_renewal;
+	now = jiffies;
+	timeout = (2 * lease) / 3 + (long)last - (long)now;
+	/* Are we close to a lease timeout? */
+	if (time_after(now, last + lease/3)) {
+		spin_unlock(&clp->cl_lock);
+		/* Queue an asynchronous RENEW. */
+		nfs4_proc_async_renew(clp);
+		timeout = (2 * lease) / 3;
+		spin_lock(&clp->cl_lock);
+	} else
+		dprintk("%s: failed to call renewd. Reason: lease not expired \n",
+				__FUNCTION__);
+	if (timeout < 5 * HZ)    /* safeguard */
+		timeout = 5 * HZ;
+	dprintk("%s: requeueing work. Lease period = %ld\n",
+			__FUNCTION__, (timeout + HZ - 1) / HZ);
+	cancel_delayed_work(&clp->cl_renewd);
+	schedule_delayed_work(&clp->cl_renewd, timeout);
+	spin_unlock(&clp->cl_lock);
+out:
+	up_read(&clp->cl_sem);
+	dprintk("%s: done\n", __FUNCTION__);
+}
+
+/* Must be called with clp->cl_sem locked for writes */
+void
+nfs4_schedule_state_renewal(struct nfs4_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",
+			__FUNCTION__, (timeout + HZ - 1) / HZ);
+	cancel_delayed_work(&clp->cl_renewd);
+	schedule_delayed_work(&clp->cl_renewd, timeout);
+	spin_unlock(&clp->cl_lock);
+}
+
+void
+nfs4_renewd_prepare_shutdown(struct nfs_server *server)
+{
+	struct nfs4_client *clp = server->nfs4_state;
+
+	if (!clp)
+		return;
+	flush_scheduled_work();
+	down_write(&clp->cl_sem);
+	if (!list_empty(&server->nfs4_siblings))
+		list_del_init(&server->nfs4_siblings);
+	up_write(&clp->cl_sem);
+}
+
+/* Must be called with clp->cl_sem locked for writes */
+void
+nfs4_kill_renewd(struct nfs4_client *clp)
+{
+	down_read(&clp->cl_sem);
+	if (!list_empty(&clp->cl_superblocks)) {
+		up_read(&clp->cl_sem);
+		return;
+	}
+	cancel_delayed_work(&clp->cl_renewd);
+	up_read(&clp->cl_sem);
+	flush_scheduled_work();
+}
+
+/*
+ * Local variables:
+ *   c-basic-offset: 8
+ * End:
+ */