NFSv4: Send RENEW requests to the server only when we're holding state

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

5 files changed, 75 insertions, 2 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 618a327027b..75dfb1c717a 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -8,6 +8,7 @@
  */
 #include <linux/config.h>
 #include <linux/completion.h>
+#include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
@@ -231,6 +232,51 @@ restart:
         spin_unlock(&clp->cl_lock);
 }
 
+int nfs_do_expire_all_delegations(void *ptr)
+{
+        struct nfs4_client *clp = ptr;
+        struct nfs_delegation *delegation;
+        struct inode *inode;
+        int err = 0;
+
+        allow_signal(SIGKILL);
+restart:
+        spin_lock(&clp->cl_lock);
+        if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
+                goto out;
+        if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
+                goto out;
+        list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
+                inode = igrab(delegation->inode);
+                if (inode == NULL)
+                        continue;
+                spin_unlock(&clp->cl_lock);
+                err = nfs_inode_return_delegation(inode);
+                iput(inode);
+                if (!err)
+                        goto restart;
+        }
+out:
+        spin_unlock(&clp->cl_lock);
+        nfs4_put_client(clp);
+        module_put_and_exit(0);
+}
+
+void nfs_expire_all_delegations(struct nfs4_client *clp)
+{
+        struct task_struct *task;
+
+        __module_get(THIS_MODULE);
+        atomic_inc(&clp->cl_count);
+        task = kthread_run(nfs_do_expire_all_delegations, clp,
+                        "%u.%u.%u.%u-delegreturn",
+                        NIPQUAD(clp->cl_addr));
+        if (!IS_ERR(task))
+                return;
+        nfs4_put_client(clp);
+        module_put(THIS_MODULE);
+}
+
 /*
  * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
  */
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index 2fcc30de924..fbc50ec271c 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -30,6 +30,7 @@ int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *s
 
 struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle);
 void nfs_return_all_delegations(struct super_block *sb);
+void nfs_expire_all_delegations(struct nfs4_client *clp);
 void nfs_handle_cb_pathdown(struct nfs4_client *clp);
 
 void nfs_delegation_mark_reclaim(struct nfs4_client *clp);
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 1d4c5b339b4..75fe646c28a 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -39,6 +39,7 @@ struct idmap;
 
 enum nfs4_client_state {
         NFS4CLNT_STATE_RECOVER  = 0,
+        NFS4CLNT_LEASE_EXPIRED,
 };
 
 /*
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 46623ac3ce8..cc33a1c32cf 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -63,6 +63,7 @@ static int nfs4_do_fsinfo(struct nfs_server *, struct nfs_fh *, struct nfs_fsinf
 static int nfs4_async_handle_error(struct rpc_task *, const struct nfs_server *);
 static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry);
 static int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception);
+static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs4_client *clp);
 extern u32 *nfs4_decode_dirent(u32 *p, struct nfs_entry *entry, int plus);
 extern struct rpc_procinfo nfs4_procedures[];
 
@@ -765,6 +766,15 @@ out:
         return -EACCES;
 }
 
+int nfs4_recover_expired_lease(struct nfs_server *server)
+{
+        struct nfs4_client *clp = server->nfs4_state;
+
+        if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
+                nfs4_schedule_state_recovery(clp);
+        return nfs4_wait_clnt_recover(server->client, clp);
+}
+
 /*
  * OPEN_EXPIRED:
  *      reclaim state on the server after a network partition.
@@ -840,6 +850,9 @@ static int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred
         int open_flags = flags & (FMODE_READ|FMODE_WRITE);
         int err;
 
+        err = nfs4_recover_expired_lease(server);
+        if (err != 0)
+                return err;
         /* Protect against reboot recovery - NOTE ORDER! */
         down_read(&clp->cl_sem);
         /* Protect against delegation recall */
@@ -921,12 +934,16 @@ static int _nfs4_do_open(struct inode *dir, struct dentry *dentry, int flags, st
         int                     status;
 
         /* Protect against reboot recovery conflicts */
-        down_read(&clp->cl_sem);
         status = -ENOMEM;
         if (!(sp = nfs4_get_state_owner(server, cred))) {
                 dprintk("nfs4_do_open: nfs4_get_state_owner failed!\n");
                 goto out_err;
         }
+        status = nfs4_recover_expired_lease(server);
+        if (status != 0)
+                goto out_err;
+        down_read(&clp->cl_sem);
+        status = -ENOMEM;
         opendata = nfs4_opendata_alloc(dentry, sp, flags, sattr);
         if (opendata == NULL)
                 goto err_put_state_owner;
@@ -2897,6 +2914,7 @@ nfs4_proc_setclientid_confirm(struct nfs4_client *clp)
                 spin_lock(&clp->cl_lock);
                 clp->cl_lease_time = fsinfo.lease_time * HZ;
                 clp->cl_last_renewal = now;
+                clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
                 spin_unlock(&clp->cl_lock);
         }
         return status;
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index a3001628ad3..f62c2f7a4ff 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -54,6 +54,7 @@
 #include <linux/nfs4.h>
 #include <linux/nfs_fs.h>
 #include "nfs4_fs.h"
+#include "delegation.h"
 
 #define NFSDBG_FACILITY NFSDBG_PROC
 
@@ -68,7 +69,7 @@ nfs4_renew_state(void *data)
         dprintk("%s: start\n", __FUNCTION__);
         /* Are there any active superblocks? */
         if (list_empty(&clp->cl_superblocks))
-                goto out; 
+                goto out;
         spin_lock(&clp->cl_lock);
         lease = clp->cl_lease_time;
         last = clp->cl_last_renewal;
@@ -76,6 +77,12 @@ nfs4_renew_state(void *data)
         timeout = (2 * lease) / 3 + (long)last - (long)now;
         /* Are we close to a lease timeout? */
         if (time_after(now, last + lease/3)) {
+                if (list_empty(&clp->cl_state_owners)) {
+                        set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+                        spin_unlock(&clp->cl_lock);
+                        nfs_expire_all_delegations(clp);
+                        goto out;
+                }
                 spin_unlock(&clp->cl_lock);
                 /* Queue an asynchronous RENEW. */
                 nfs4_proc_async_renew(clp);