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 * TODO: If the send queue gets backlogged (e.g., if the server goes down), 40 * we will keep filling the queue with periodic RENEW requests. We need a 41 * mechanism for ensuring that if renewd successfully sends off a request, 42 * then it only wakes up when the request is finished. Maybe use the 43 * child task framework of the RPC layer? 44 */ 45 46 #include <linux/mm.h> 47 #include <linux/pagemap.h> 48 #include <linux/sunrpc/sched.h> 49 #include <linux/sunrpc/clnt.h> 50 51 #include <linux/nfs.h> 52 #include <linux/nfs4.h> 53 #include <linux/nfs_fs.h> 54 #include "nfs4_fs.h" 55 #include "delegation.h" 56 57 #define NFSDBG_FACILITY NFSDBG_PROC 58 59 void 60 nfs4_renew_state(struct work_struct *work) 61 { 62 struct nfs4_state_maintenance_ops *ops; 63 struct nfs_client *clp = 64 container_of(work, struct nfs_client, cl_renewd.work); 65 struct rpc_cred *cred; 66 long lease, timeout; 67 unsigned long last, now; 68 69 ops = nfs4_state_renewal_ops[clp->cl_minorversion]; 70 dprintk("%s: start\n", __func__); 71 /* Are there any active superblocks? */ 72 if (list_empty(&clp->cl_superblocks)) 73 goto out; 74 spin_lock(&clp->cl_lock); 75 lease = clp->cl_lease_time; 76 last = clp->cl_last_renewal; 77 now = jiffies; 78 timeout = (2 * lease) / 3 + (long)last - (long)now; 79 /* Are we close to a lease timeout? */ 80 if (time_after(now, last + lease/3)) { 81 cred = ops->get_state_renewal_cred_locked(clp); 82 spin_unlock(&clp->cl_lock); 83 if (cred == NULL) { 84 if (list_empty(&clp->cl_delegations)) { 85 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 86 goto out; 87 } 88 nfs_expire_all_delegations(clp); 89 } else { 90 /* Queue an asynchronous RENEW. */ 91 ops->sched_state_renewal(clp, cred); 92 put_rpccred(cred); 93 } 94 timeout = (2 * lease) / 3; 95 spin_lock(&clp->cl_lock); 96 } else 97 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 98 __func__); 99 if (timeout < 5 * HZ) /* safeguard */ 100 timeout = 5 * HZ; 101 dprintk("%s: requeueing work. Lease period = %ld\n", 102 __func__, (timeout + HZ - 1) / HZ); 103 cancel_delayed_work(&clp->cl_renewd); 104 schedule_delayed_work(&clp->cl_renewd, timeout); 105 spin_unlock(&clp->cl_lock); 106 nfs_expire_unreferenced_delegations(clp); 107 out: 108 dprintk("%s: done\n", __func__); 109 } 110 111 void 112 nfs4_schedule_state_renewal(struct nfs_client *clp) 113 { 114 long timeout; 115 116 spin_lock(&clp->cl_lock); 117 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 118 - (long)jiffies; 119 if (timeout < 5 * HZ) 120 timeout = 5 * HZ; 121 dprintk("%s: requeueing work. Lease period = %ld\n", 122 __func__, (timeout + HZ - 1) / HZ); 123 cancel_delayed_work(&clp->cl_renewd); 124 schedule_delayed_work(&clp->cl_renewd, timeout); 125 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 126 spin_unlock(&clp->cl_lock); 127 } 128 129 void 130 nfs4_kill_renewd(struct nfs_client *clp) 131 { 132 cancel_delayed_work_sync(&clp->cl_renewd); 133 } 134 135 /* 136 * Local variables: 137 * c-basic-offset: 8 138 * End: 139 */ 140