NFSv4: The NFSv4.0 client must send RENEW calls if it holds a delegation
Trond Myklebust [Wed, 24 Aug 2011 19:07:37 +0000 (15:07 -0400)]
RFC3530 states that if the client holds a delegation, then it is obliged
to continue to send RENEW calls once every lease period in order to allow
the server to return NFS4ERR_CB_PATH_DOWN if the callback path is
unreachable.

This is not required for NFSv4.1, since the server can at any time set
the SEQ4_STATUS_CB_PATH_DOWN_SESSION in any SEQUENCE operation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4_fs.h
fs/nfs/nfs4proc.c
fs/nfs/nfs4renewd.c

index 58adfb6..e1b6607 100644 (file)
@@ -56,6 +56,9 @@ enum nfs4_session_state {
        NFS4_SESSION_DRAINING,
 };
 
+#define NFS4_RENEW_TIMEOUT             0x01
+#define NFS4_RENEW_DELEGATION_CB       0x02
+
 struct nfs4_minor_version_ops {
        u32     minor_version;
 
@@ -225,7 +228,7 @@ struct nfs4_state_recovery_ops {
 };
 
 struct nfs4_state_maintenance_ops {
-       int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *);
+       int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned);
        struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *);
        int (*renew_lease)(struct nfs_client *, struct rpc_cred *);
 };
index b358ec1..e89940a 100644 (file)
@@ -3386,7 +3386,7 @@ static const struct rpc_call_ops nfs4_renew_ops = {
        .rpc_release = nfs4_renew_release,
 };
 
-static int nfs4_proc_async_renew(struct nfs_client *clp, struct rpc_cred *cred)
+static int nfs4_proc_async_renew(struct nfs_client *clp, struct rpc_cred *cred, unsigned renew_flags)
 {
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_RENEW],
@@ -3395,6 +3395,8 @@ static int nfs4_proc_async_renew(struct nfs_client *clp, struct rpc_cred *cred)
        };
        struct nfs4_renewdata *data;
 
+       if (renew_flags == 0)
+               return 0;
        if (!atomic_inc_not_zero(&clp->cl_count))
                return -EIO;
        data = kmalloc(sizeof(*data), GFP_NOFS);
@@ -5504,11 +5506,13 @@ static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp, struct rpc_
        return rpc_run_task(&task_setup_data);
 }
 
-static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cred)
+static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cred, unsigned renew_flags)
 {
        struct rpc_task *task;
        int ret = 0;
 
+       if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0)
+               return 0;
        task = _nfs41_proc_sequence(clp, cred);
        if (IS_ERR(task))
                ret = PTR_ERR(task);
index df8e7f3..dc484c0 100644 (file)
@@ -60,6 +60,7 @@ nfs4_renew_state(struct work_struct *work)
        struct rpc_cred *cred;
        long lease;
        unsigned long last, now;
+       unsigned renew_flags = 0;
 
        ops = clp->cl_mvops->state_renewal_ops;
        dprintk("%s: start\n", __func__);
@@ -72,18 +73,23 @@ nfs4_renew_state(struct work_struct *work)
        last = clp->cl_last_renewal;
        now = jiffies;
        /* Are we close to a lease timeout? */
-       if (time_after(now, last + lease/3)) {
+       if (time_after(now, last + lease/3))
+               renew_flags |= NFS4_RENEW_TIMEOUT;
+       if (nfs_delegations_present(clp))
+               renew_flags |= NFS4_RENEW_DELEGATION_CB;
+
+       if (renew_flags != 0) {
                cred = ops->get_state_renewal_cred_locked(clp);
                spin_unlock(&clp->cl_lock);
                if (cred == NULL) {
-                       if (!nfs_delegations_present(clp)) {
+                       if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
                                set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
                                goto out;
                        }
                        nfs_expire_all_delegations(clp);
                } else {
                        /* Queue an asynchronous RENEW. */
-                       ops->sched_state_renewal(clp, cred);
+                       ops->sched_state_renewal(clp, cred, renew_flags);
                        put_rpccred(cred);
                        goto out_exp;
                }