NFS: Stop sillyname renames and unmounts from racing

Added an active/deactive mechanism to the nfs_server structure
allowing async operations to hold off umount until the
operations are done.

Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index a6f625497612..c3740f5ab978 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -729,6 +729,9 @@ static struct nfs_server *nfs_alloc_server(void)
         INIT_LIST_HEAD(&server->client_link);
         INIT_LIST_HEAD(&server->master_link);
 
+        init_waitqueue_head(&server->active_wq);
+        atomic_set(&server->active, 0);
+
         server->io_stats = nfs_alloc_iostats();
         if (!server->io_stats) {
                 kfree(server);