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 int ret; 92 93 /* Queue an asynchronous RENEW. */ 94 ret = ops->sched_state_renewal(clp, cred, renew_flags); 95 put_rpccred(cred); 96 switch (ret) { 97 default: 98 goto out_exp; 99 case -EAGAIN: 100 case -ENOMEM: 101 break; 102 } 103 } 104 } else { 105 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 106 __func__); 107 spin_unlock(&clp->cl_lock); 108 } 109 nfs4_schedule_state_renewal(clp); 110 out_exp: 111 nfs_expire_unreferenced_delegations(clp); 112 out: 113 dprintk("%s: done\n", __func__); 114 } 115 116 void 117 nfs4_schedule_state_renewal(struct nfs_client *clp) 118 { 119 long timeout; 120 121 spin_lock(&clp->cl_lock); 122 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 123 - (long)jiffies; 124 if (timeout < 5 * HZ) 125 timeout = 5 * HZ; 126 dprintk("%s: requeueing work. Lease period = %ld\n", 127 __func__, (timeout + HZ - 1) / HZ); 128 mod_delayed_work(system_wq, &clp->cl_renewd, timeout); 129 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 130 spin_unlock(&clp->cl_lock); 131 } 132 133 void 134 nfs4_kill_renewd(struct nfs_client *clp) 135 { 136 cancel_delayed_work_sync(&clp->cl_renewd); 137 } 138 139 /** 140 * nfs4_set_lease_period - Sets the lease period on a nfs_client 141 * 142 * @clp: pointer to nfs_client 143 * @lease: new value for lease period 144 * @lastrenewed: time at which lease was last renewed 145 */ 146 void nfs4_set_lease_period(struct nfs_client *clp, 147 unsigned long lease, 148 unsigned long lastrenewed) 149 { 150 spin_lock(&clp->cl_lock); 151 clp->cl_lease_time = lease; 152 clp->cl_last_renewal = lastrenewed; 153 spin_unlock(&clp->cl_lock); 154 155 /* Cap maximum reconnect timeout at 1/2 lease period */ 156 rpc_cap_max_reconnect_timeout(clp->cl_rpcclient, lease >> 1); 157 } 158 159 /* 160 * Local variables: 161 * c-basic-offset: 8 162 * End: 163 */ 164