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 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 unsigned renew_flags = 0; 64 65 ops = clp->cl_mvops->state_renewal_ops; 66 dprintk("%s: start\n", __func__); 67 68 if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state)) 69 goto out; 70 71 spin_lock(&clp->cl_lock); 72 lease = clp->cl_lease_time; 73 last = clp->cl_last_renewal; 74 now = jiffies; 75 /* Are we close to a lease timeout? */ 76 if (time_after(now, last + lease/3)) 77 renew_flags |= NFS4_RENEW_TIMEOUT; 78 if (nfs_delegations_present(clp)) 79 renew_flags |= NFS4_RENEW_DELEGATION_CB; 80 81 if (renew_flags != 0) { 82 cred = ops->get_state_renewal_cred_locked(clp); 83 spin_unlock(&clp->cl_lock); 84 if (cred == NULL) { 85 if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) { 86 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 87 goto out; 88 } 89 nfs_expire_all_delegations(clp); 90 } else { 91 /* Queue an asynchronous RENEW. */ 92 ops->sched_state_renewal(clp, cred, renew_flags); 93 put_rpccred(cred); 94 goto out_exp; 95 } 96 } else { 97 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 98 __func__); 99 spin_unlock(&clp->cl_lock); 100 } 101 nfs4_schedule_state_renewal(clp); 102 out_exp: 103 nfs_expire_unreferenced_delegations(clp); 104 out: 105 dprintk("%s: done\n", __func__); 106 } 107 108 void 109 nfs4_schedule_state_renewal(struct nfs_client *clp) 110 { 111 long timeout; 112 113 spin_lock(&clp->cl_lock); 114 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 115 - (long)jiffies; 116 if (timeout < 5 * HZ) 117 timeout = 5 * HZ; 118 dprintk("%s: requeueing work. Lease period = %ld\n", 119 __func__, (timeout + HZ - 1) / HZ); 120 cancel_delayed_work(&clp->cl_renewd); 121 schedule_delayed_work(&clp->cl_renewd, timeout); 122 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 123 spin_unlock(&clp->cl_lock); 124 } 125 126 void 127 nfs4_kill_renewd(struct nfs_client *clp) 128 { 129 cancel_delayed_work_sync(&clp->cl_renewd); 130 } 131 132 /* 133 * Local variables: 134 * c-basic-offset: 8 135 * End: 136 */ 137