1 files changed, 49 insertions, 1 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 9da72b8a554..df05b946514 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -1044,6 +1044,48 @@ static void nfs4blocklayout_unregister_sb(struct super_block *sb,
 		rpc_unlink(pipe->dentry);
 }
 
+static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
+			   void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *dentry;
+	int ret = 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	if (nn->bl_device_pipe == NULL) {
+		module_put(THIS_MODULE);
+		return 0;
+	}
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			break;
+		}
+		nn->bl_device_pipe->dentry = dentry;
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		if (nn->bl_device_pipe->dentry)
+			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfs4blocklayout_block = {
+	.notifier_call = rpc_pipefs_event,
+};
+
 static struct dentry *nfs4blocklayout_register_net(struct net *net,
 						   struct rpc_pipe *pipe)
 {
@@ -1119,12 +1161,17 @@ static int __init nfs4blocklayout_init(void)
 		ret = PTR_ERR(mnt);
 		goto out_remove;
 	}
-	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
 	if (ret)
 		goto out_remove;
+	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+	if (ret)
+		goto out_notifier;
 out:
 	return ret;
 
+out_notifier:
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
 out_remove:
 	pnfs_unregister_layoutdriver(&blocklayout_type);
 	return ret;
@@ -1135,6 +1182,7 @@ static void __exit nfs4blocklayout_exit(void)
 	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
 	       __func__);
 
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
 	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
 	pnfs_unregister_layoutdriver(&blocklayout_type);
 }