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 nfs_client *clp = 63 container_of(work, struct nfs_client, cl_renewd.work); 64 struct rpc_cred *cred; 65 long lease, timeout; 66 unsigned long last, now; 67 68 down_read(&clp->cl_sem); 69 dprintk("%s: start\n", __FUNCTION__); 70 /* Are there any active superblocks? */ 71 if (list_empty(&clp->cl_superblocks)) 72 goto out; 73 spin_lock(&clp->cl_lock); 74 lease = clp->cl_lease_time; 75 last = clp->cl_last_renewal; 76 now = jiffies; 77 timeout = (2 * lease) / 3 + (long)last - (long)now; 78 /* Are we close to a lease timeout? */ 79 if (time_after(now, last + lease/3)) { 80 cred = nfs4_get_renew_cred(clp); 81 if (cred == NULL) { 82 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 83 spin_unlock(&clp->cl_lock); 84 nfs_expire_all_delegations(clp); 85 goto out; 86 } 87 spin_unlock(&clp->cl_lock); 88 /* Queue an asynchronous RENEW. */ 89 nfs4_proc_async_renew(clp, cred); 90 put_rpccred(cred); 91 timeout = (2 * lease) / 3; 92 spin_lock(&clp->cl_lock); 93 } else 94 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 95 __FUNCTION__); 96 if (timeout < 5 * HZ) /* safeguard */ 97 timeout = 5 * HZ; 98 dprintk("%s: requeueing work. Lease period = %ld\n", 99 __FUNCTION__, (timeout + HZ - 1) / HZ); 100 cancel_delayed_work(&clp->cl_renewd); 101 schedule_delayed_work(&clp->cl_renewd, timeout); 102 spin_unlock(&clp->cl_lock); 103 out: 104 up_read(&clp->cl_sem); 105 dprintk("%s: done\n", __FUNCTION__); 106 } 107 108 /* Must be called with clp->cl_sem locked for writes */ 109 void 110 nfs4_schedule_state_renewal(struct nfs_client *clp) 111 { 112 long timeout; 113 114 spin_lock(&clp->cl_lock); 115 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 116 - (long)jiffies; 117 if (timeout < 5 * HZ) 118 timeout = 5 * HZ; 119 dprintk("%s: requeueing work. Lease period = %ld\n", 120 __FUNCTION__, (timeout + HZ - 1) / HZ); 121 cancel_delayed_work(&clp->cl_renewd); 122 schedule_delayed_work(&clp->cl_renewd, timeout); 123 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 124 spin_unlock(&clp->cl_lock); 125 } 126 127 void 128 nfs4_renewd_prepare_shutdown(struct nfs_server *server) 129 { 130 cancel_delayed_work(&server->nfs_client->cl_renewd); 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 * Local variables: 141 * c-basic-offset: 8 142 * End: 143 */ 144