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 const struct 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 lease = clp->cl_lease_time; 72 last = clp->cl_last_renewal; 73 now = jiffies; 74 /* Are we close to a lease timeout? */ 75 if (time_after(now, last + lease/3)) 76 renew_flags |= NFS4_RENEW_TIMEOUT; 77 if (nfs_delegations_present(clp)) 78 renew_flags |= NFS4_RENEW_DELEGATION_CB; 79 80 if (renew_flags != 0) { 81 cred = ops->get_state_renewal_cred(clp); 82 if (cred == NULL) { 83 if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) { 84 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 85 goto out; 86 } 87 nfs_expire_all_delegations(clp); 88 } else { 89 int ret; 90 91 /* Queue an asynchronous RENEW. */ 92 ret = ops->sched_state_renewal(clp, cred, renew_flags); 93 put_cred(cred); 94 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 nfs4_schedule_state_renewal(clp); 107 out_exp: 108 nfs_expire_unreferenced_delegations(clp); 109 out: 110 dprintk("%s: done\n", __func__); 111 } 112 113 void 114 nfs4_schedule_state_renewal(struct nfs_client *clp) 115 { 116 long timeout; 117 118 spin_lock(&clp->cl_lock); 119 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 120 - (long)jiffies; 121 if (timeout < 5 * HZ) 122 timeout = 5 * HZ; 123 dprintk("%s: requeueing work. Lease period = %ld\n", 124 __func__, (timeout + HZ - 1) / HZ); 125 mod_delayed_work(system_wq, &clp->cl_renewd, timeout); 126 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 127 spin_unlock(&clp->cl_lock); 128 } 129 130 void 131 nfs4_kill_renewd(struct nfs_client *clp) 132 { 133 cancel_delayed_work_sync(&clp->cl_renewd); 134 } 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 void nfs4_set_lease_period(struct nfs_client *clp, 143 unsigned long lease) 144 { 145 spin_lock(&clp->cl_lock); 146 clp->cl_lease_time = lease; 147 spin_unlock(&clp->cl_lock); 148 149 /* Cap maximum reconnect timeout at 1/2 lease period */ 150 rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1); 151 } 152