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