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_PROC 53 54 void 55 nfs4_renew_state(struct work_struct *work) 56 { 57 const struct nfs4_state_maintenance_ops *ops; 58 struct nfs_client *clp = 59 container_of(work, struct nfs_client, cl_renewd.work); 60 struct rpc_cred *cred; 61 long lease; 62 unsigned long last, now; 63 64 ops = clp->cl_mvops->state_renewal_ops; 65 dprintk("%s: start\n", __func__); 66 67 rcu_read_lock(); 68 if (list_empty(&clp->cl_superblocks)) { 69 rcu_read_unlock(); 70 goto out; 71 } 72 rcu_read_unlock(); 73 74 spin_lock(&clp->cl_lock); 75 lease = clp->cl_lease_time; 76 last = clp->cl_last_renewal; 77 now = jiffies; 78 /* Are we close to a lease timeout? */ 79 if (time_after(now, last + lease/3)) { 80 cred = ops->get_state_renewal_cred_locked(clp); 81 spin_unlock(&clp->cl_lock); 82 if (cred == NULL) { 83 if (!nfs_delegations_present(clp)) { 84 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 85 goto out; 86 } 87 nfs_expire_all_delegations(clp); 88 } else { 89 /* Queue an asynchronous RENEW. */ 90 ops->sched_state_renewal(clp, cred); 91 put_rpccred(cred); 92 goto out_exp; 93 } 94 } else { 95 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 96 __func__); 97 spin_unlock(&clp->cl_lock); 98 } 99 nfs4_schedule_state_renewal(clp); 100 out_exp: 101 nfs_expire_unreferenced_delegations(clp); 102 out: 103 dprintk("%s: done\n", __func__); 104 } 105 106 void 107 nfs4_schedule_state_renewal(struct nfs_client *clp) 108 { 109 long timeout; 110 111 spin_lock(&clp->cl_lock); 112 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 113 - (long)jiffies; 114 if (timeout < 5 * HZ) 115 timeout = 5 * HZ; 116 dprintk("%s: requeueing work. Lease period = %ld\n", 117 __func__, (timeout + HZ - 1) / HZ); 118 cancel_delayed_work(&clp->cl_renewd); 119 schedule_delayed_work(&clp->cl_renewd, timeout); 120 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 121 spin_unlock(&clp->cl_lock); 122 } 123 124 void 125 nfs4_kill_renewd(struct nfs_client *clp) 126 { 127 cancel_delayed_work_sync(&clp->cl_renewd); 128 } 129 130 /* 131 * Local variables: 132 * c-basic-offset: 8 133 * End: 134 */ 135