NFSv4.1: new flag for state renewal check

Data servers not sharing a session with the mount MDS always have an empty
cl_superblocks list.
Replace the cl_superblocks empty list check to see if it is time to shut down
renewd with the NFS_CS_STOP_RENEW bit which is not set by such a data server.

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

2 files changed, 6 insertions, 5 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index b9ed2a8bc26a..a86698cd82fd 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1019,14 +1019,19 @@ static void nfs_server_insert_lists(struct nfs_server *server)
         spin_lock(&nfs_client_lock);
         list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
         list_add_tail(&server->master_link, &nfs_volume_list);
+        clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
         spin_unlock(&nfs_client_lock);
 
 }
 
 static void nfs_server_remove_lists(struct nfs_server *server)
 {
+        struct nfs_client *clp = server->nfs_client;
+
         spin_lock(&nfs_client_lock);
         list_del_rcu(&server->client_link);
+        if (clp && list_empty(&clp->cl_superblocks))
+                set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
         list_del(&server->master_link);
         spin_unlock(&nfs_client_lock);
 
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 402143d75fc5..df8e7f3ca56d 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -64,12 +64,8 @@ nfs4_renew_state(struct work_struct *work)
         ops = clp->cl_mvops->state_renewal_ops;
         dprintk("%s: start\n", __func__);
 
-        rcu_read_lock();
-        if (list_empty(&clp->cl_superblocks)) {
-                rcu_read_unlock();
+        if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
                 goto out;
-        }
-        rcu_read_unlock();
 
         spin_lock(&clp->cl_lock);
         lease = clp->cl_lease_time;