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/smp_lock.h> 47 #include <linux/mm.h> 48 #include <linux/pagemap.h> 49 #include <linux/sunrpc/sched.h> 50 #include <linux/sunrpc/clnt.h> 51 52 #include <linux/nfs.h> 53 #include <linux/nfs4.h> 54 #include <linux/nfs_fs.h> 55 #include "nfs4_fs.h" 56 #include "delegation.h" 57 58 #define NFSDBG_FACILITY NFSDBG_PROC 59 60 void 61 nfs4_renew_state(struct work_struct *work) 62 { 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 down_read(&clp->cl_sem); 70 dprintk("%s: start\n", __FUNCTION__); 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 = nfs4_get_renew_cred(clp); 82 if (cred == NULL) { 83 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state); 84 spin_unlock(&clp->cl_lock); 85 nfs_expire_all_delegations(clp); 86 goto out; 87 } 88 spin_unlock(&clp->cl_lock); 89 /* Queue an asynchronous RENEW. */ 90 nfs4_proc_async_renew(clp, cred); 91 put_rpccred(cred); 92 timeout = (2 * lease) / 3; 93 spin_lock(&clp->cl_lock); 94 } else 95 dprintk("%s: failed to call renewd. Reason: lease not expired \n", 96 __FUNCTION__); 97 if (timeout < 5 * HZ) /* safeguard */ 98 timeout = 5 * HZ; 99 dprintk("%s: requeueing work. Lease period = %ld\n", 100 __FUNCTION__, (timeout + HZ - 1) / HZ); 101 cancel_delayed_work(&clp->cl_renewd); 102 schedule_delayed_work(&clp->cl_renewd, timeout); 103 spin_unlock(&clp->cl_lock); 104 out: 105 up_read(&clp->cl_sem); 106 dprintk("%s: done\n", __FUNCTION__); 107 } 108 109 /* Must be called with clp->cl_sem locked for writes */ 110 void 111 nfs4_schedule_state_renewal(struct nfs_client *clp) 112 { 113 long timeout; 114 115 spin_lock(&clp->cl_lock); 116 timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal 117 - (long)jiffies; 118 if (timeout < 5 * HZ) 119 timeout = 5 * HZ; 120 dprintk("%s: requeueing work. Lease period = %ld\n", 121 __FUNCTION__, (timeout + HZ - 1) / HZ); 122 cancel_delayed_work(&clp->cl_renewd); 123 schedule_delayed_work(&clp->cl_renewd, timeout); 124 set_bit(NFS_CS_RENEWD, &clp->cl_res_state); 125 spin_unlock(&clp->cl_lock); 126 } 127 128 void 129 nfs4_renewd_prepare_shutdown(struct nfs_server *server) 130 { 131 flush_scheduled_work(); 132 } 133 134 void 135 nfs4_kill_renewd(struct nfs_client *clp) 136 { 137 down_read(&clp->cl_sem); 138 cancel_delayed_work(&clp->cl_renewd); 139 up_read(&clp->cl_sem); 140 flush_scheduled_work(); 141 } 142 143 /* 144 * Local variables: 145 * c-basic-offset: 8 146 * End: 147 */ 148