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       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                 :            :  */
      40                 :            : 
      41                 :            : #include <linux/mm.h>
      42                 :            : #include <linux/pagemap.h>
      43                 :            : #include <linux/sunrpc/sched.h>
      44                 :            : #include <linux/sunrpc/clnt.h>
      45                 :            : 
      46                 :            : #include <linux/nfs.h>
      47                 :            : #include <linux/nfs4.h>
      48                 :            : #include <linux/nfs_fs.h>
      49                 :            : #include "nfs4_fs.h"
      50                 :            : #include "delegation.h"
      51                 :            : 
      52                 :            : #define NFSDBG_FACILITY         NFSDBG_STATE
      53                 :            : 
      54                 :            : void
      55                 :          0 : nfs4_renew_state(struct work_struct *work)
      56                 :            : {
      57                 :            :         const struct nfs4_state_maintenance_ops *ops;
      58                 :            :         struct nfs_client *clp =
      59                 :          0 :                 container_of(work, struct nfs_client, cl_renewd.work);
      60                 :            :         const struct cred *cred;
      61                 :            :         long lease;
      62                 :            :         unsigned long last, now;
      63                 :            :         unsigned renew_flags = 0;
      64                 :            : 
      65                 :          0 :         ops = clp->cl_mvops->state_renewal_ops;
      66                 :            :         dprintk("%s: start\n", __func__);
      67                 :            : 
      68                 :          0 :         if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
      69                 :            :                 goto out;
      70                 :            : 
      71                 :          0 :         lease = clp->cl_lease_time;
      72                 :          0 :         last = clp->cl_last_renewal;
      73                 :          0 :         now = jiffies;
      74                 :            :         /* Are we close to a lease timeout? */
      75                 :          0 :         if (time_after(now, last + lease/3))
      76                 :            :                 renew_flags |= NFS4_RENEW_TIMEOUT;
      77                 :          0 :         if (nfs_delegations_present(clp))
      78                 :          0 :                 renew_flags |= NFS4_RENEW_DELEGATION_CB;
      79                 :            : 
      80                 :          0 :         if (renew_flags != 0) {
      81                 :          0 :                 cred = ops->get_state_renewal_cred(clp);
      82                 :          0 :                 if (cred == NULL) {
      83                 :          0 :                         if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
      84                 :          0 :                                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
      85                 :          0 :                                 goto out;
      86                 :            :                         }
      87                 :          0 :                         nfs_expire_all_delegations(clp);
      88                 :            :                 } else {
      89                 :            :                         int ret;
      90                 :            : 
      91                 :            :                         /* Queue an asynchronous RENEW. */
      92                 :          0 :                         ret = ops->sched_state_renewal(clp, cred, renew_flags);
      93                 :          0 :                         put_cred(cred);
      94                 :          0 :                         switch (ret) {
      95                 :            :                         default:
      96                 :            :                                 goto out_exp;
      97                 :            :                         case -EAGAIN:
      98                 :            :                         case -ENOMEM:
      99                 :            :                                 break;
     100                 :            :                         }
     101                 :            :                 }
     102                 :            :         } else {
     103                 :            :                 dprintk("%s: failed to call renewd. Reason: lease not expired \n",
     104                 :            :                                 __func__);
     105                 :            :         }
     106                 :          0 :         nfs4_schedule_state_renewal(clp);
     107                 :            : out_exp:
     108                 :          0 :         nfs_expire_unreferenced_delegations(clp);
     109                 :            : out:
     110                 :            :         dprintk("%s: done\n", __func__);
     111                 :          0 : }
     112                 :            : 
     113                 :            : void
     114                 :          0 : nfs4_schedule_state_renewal(struct nfs_client *clp)
     115                 :            : {
     116                 :            :         long timeout;
     117                 :            : 
     118                 :            :         spin_lock(&clp->cl_lock);
     119                 :          0 :         timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
     120                 :          0 :                 - (long)jiffies;
     121                 :          0 :         if (timeout < 5 * HZ)
     122                 :            :                 timeout = 5 * HZ;
     123                 :            :         dprintk("%s: requeueing work. Lease period = %ld\n",
     124                 :            :                         __func__, (timeout + HZ - 1) / HZ);
     125                 :          0 :         mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
     126                 :          0 :         set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
     127                 :            :         spin_unlock(&clp->cl_lock);
     128                 :          0 : }
     129                 :            : 
     130                 :            : void
     131                 :          0 : nfs4_kill_renewd(struct nfs_client *clp)
     132                 :            : {
     133                 :          0 :         cancel_delayed_work_sync(&clp->cl_renewd);
     134                 :          0 : }
     135                 :            : 
     136                 :            : /**
     137                 :            :  * nfs4_set_lease_period - Sets the lease period on a nfs_client
     138                 :            :  *
     139                 :            :  * @clp: pointer to nfs_client
     140                 :            :  * @lease: new value for lease period
     141                 :            :  */
     142                 :          0 : void nfs4_set_lease_period(struct nfs_client *clp,
     143                 :            :                 unsigned long lease)
     144                 :            : {
     145                 :            :         spin_lock(&clp->cl_lock);
     146                 :          0 :         clp->cl_lease_time = lease;
     147                 :            :         spin_unlock(&clp->cl_lock);
     148                 :            : 
     149                 :            :         /* Cap maximum reconnect timeout at 1/2 lease period */
     150                 :          0 :         rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1);
     151                 :          0 : }
     152                 :            : 
     153                 :            : /*
     154                 :            :  * Local variables:
     155                 :            :  *   c-basic-offset: 8
     156                 :            :  * End:
     157                 :            :  */