[linux-2.6-block.git] / fs / nfs / nfs4renewd.c

/*
 *  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/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_PROC

void
nfs4_renew_state(struct work_struct *work)
{
	struct nfs_client *clp =
		container_of(work, struct nfs_client, cl_renewd.work);
	struct rpc_cred *cred;
	long lease, timeout;
	unsigned long last, now;

	down_read(&clp->cl_sem);
	dprintk("%s: start\n", __func__);
	/* 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)) {
		cred = nfs4_get_renew_cred(clp);
		if (cred == NULL) {
			set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
			spin_unlock(&clp->cl_lock);
			nfs_expire_all_delegations(clp);
			goto out;
		}
		spin_unlock(&clp->cl_lock);
		/* Queue an asynchronous RENEW. */
		nfs4_proc_async_renew(clp, cred);
		put_rpccred(cred);
		timeout = (2 * lease) / 3;
		spin_lock(&clp->cl_lock);
	} else
		dprintk("%s: failed to call renewd. Reason: lease not expired \n",
				__func__);
	if (timeout < 5 * HZ)    /* safeguard */
		timeout = 5 * HZ;
	dprintk("%s: requeueing work. Lease period = %ld\n",
			__func__, (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", __func__);
}

/* Must be called with clp->cl_sem locked for writes */
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);
	cancel_delayed_work(&clp->cl_renewd);
	schedule_delayed_work(&clp->cl_renewd, timeout);
	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
	spin_unlock(&clp->cl_lock);
}

void
nfs4_renewd_prepare_shutdown(struct nfs_server *server)
{
	cancel_delayed_work(&server->nfs_client->cl_renewd);
}

void
nfs4_kill_renewd(struct nfs_client *clp)
{
	cancel_delayed_work_sync(&clp->cl_renewd);
}

/*
 * Local variables:
 *   c-basic-offset: 8
 * End:
 */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* fs/nfs/nfs4renewd.c
	3	*
	4	* Copyright (c) 2002 The Regents of the University of Michigan.
	5	* All rights reserved.
	6	*
	7	* Kendrick Smith <kmsmith@umich.edu>
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	*
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. Neither the name of the University nor the names of its
	19	* contributors may be used to endorse or promote products derived
	20	* from this software without specific prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	23	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	24	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	25	* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	27	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	28	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	29	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	30	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	31	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	32	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	33	*
	34	* Implementation of the NFSv4 "renew daemon", which wakes up periodically to
	35	* send a RENEW, to keep state alive on the server. The daemon is implemented
	36	* as an rpc_task, not a real kernel thread, so it always runs in rpciod's
	37	* context. There is one renewd per nfs_server.
	38	*
	39	* TODO: If the send queue gets backlogged (e.g., if the server goes down),
	40	* we will keep filling the queue with periodic RENEW requests. We need a
	41	* mechanism for ensuring that if renewd successfully sends off a request,
	42	* then it only wakes up when the request is finished. Maybe use the
	43	* child task framework of the RPC layer?
	44	*/
	45
1da177e4 LT	46	#include <linux/mm.h>
	47	#include <linux/pagemap.h>
	48	#include <linux/sunrpc/sched.h>
	49	#include <linux/sunrpc/clnt.h>
	50
	51	#include <linux/nfs.h>
	52	#include <linux/nfs4.h>
	53	#include <linux/nfs_fs.h>
4ce79717	54	#include "nfs4_fs.h"
58d9714a	55	#include "delegation.h"
1da177e4 LT	56
	57	#define NFSDBG_FACILITY NFSDBG_PROC
	58
	59	void
65f27f38	60	nfs4_renew_state(struct work_struct *work)
1da177e4	61	{
65f27f38 DH	62	struct nfs_client *clp =
65f27f38 DH	63	container_of(work, struct nfs_client, cl_renewd.work);
b4454fe1	64	struct rpc_cred *cred;
1da177e4 LT	65	long lease, timeout;
	66	unsigned long last, now;
	67
	68	down_read(&clp->cl_sem);
3110ff80	69	dprintk("%s: start\n", __func__);
1da177e4 LT	70	/* Are there any active superblocks? */
1da177e4 LT	71	if (list_empty(&clp->cl_superblocks))
58d9714a	72	goto out;
1da177e4 LT	73	spin_lock(&clp->cl_lock);
	74	lease = clp->cl_lease_time;
	75	last = clp->cl_last_renewal;
	76	now = jiffies;
	77	timeout = (2 * lease) / 3 + (long)last - (long)now;
	78	/* Are we close to a lease timeout? */
	79	if (time_after(now, last + lease/3)) {
b4454fe1 TM	80	cred = nfs4_get_renew_cred(clp);
b4454fe1 TM	81	if (cred == NULL) {
58d9714a TM	82	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
	83	spin_unlock(&clp->cl_lock);
	84	nfs_expire_all_delegations(clp);
	85	goto out;
	86	}
1da177e4 LT	87	spin_unlock(&clp->cl_lock);
1da177e4 LT	88	/* Queue an asynchronous RENEW. */
b4454fe1 TM	89	nfs4_proc_async_renew(clp, cred);
b4454fe1 TM	90	put_rpccred(cred);
1da177e4 LT	91	timeout = (2 * lease) / 3;
	92	spin_lock(&clp->cl_lock);
	93	} else
	94	dprintk("%s: failed to call renewd. Reason: lease not expired \n",
3110ff80	95	__func__);
1da177e4 LT	96	if (timeout < 5 * HZ) /* safeguard */
	97	timeout = 5 * HZ;
	98	dprintk("%s: requeueing work. Lease period = %ld\n",
3110ff80	99	__func__, (timeout + HZ - 1) / HZ);
1da177e4 LT	100	cancel_delayed_work(&clp->cl_renewd);
	101	schedule_delayed_work(&clp->cl_renewd, timeout);
	102	spin_unlock(&clp->cl_lock);
	103	out:
	104	up_read(&clp->cl_sem);
3110ff80	105	dprintk("%s: done\n", __func__);
1da177e4 LT	106	}
	107
	108	/* Must be called with clp->cl_sem locked for writes */
	109	void
adfa6f98	110	nfs4_schedule_state_renewal(struct nfs_client *clp)
1da177e4 LT	111	{
	112	long timeout;
	113
	114	spin_lock(&clp->cl_lock);
	115	timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
	116	- (long)jiffies;
	117	if (timeout < 5 * HZ)
	118	timeout = 5 * HZ;
	119	dprintk("%s: requeueing work. Lease period = %ld\n",
3110ff80	120	__func__, (timeout + HZ - 1) / HZ);
1da177e4 LT	121	cancel_delayed_work(&clp->cl_renewd);
1da177e4 LT	122	schedule_delayed_work(&clp->cl_renewd, timeout);
5dd3177a	123	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
1da177e4 LT	124	spin_unlock(&clp->cl_lock);
	125	}
	126
	127	void
	128	nfs4_renewd_prepare_shutdown(struct nfs_server *server)
	129	{
3d39c691	130	cancel_delayed_work(&server->nfs_client->cl_renewd);
1da177e4 LT	131	}
1da177e4 LT	132
1da177e4	133	void
adfa6f98	134	nfs4_kill_renewd(struct nfs_client *clp)
1da177e4	135	{
3d39c691	136	cancel_delayed_work_sync(&clp->cl_renewd);
1da177e4 LT	137	}
	138
	139	/*
	140	* Local variables:
	141	* c-basic-offset: 8
	142	* End:
	143	*/