1 files changed, 24 insertions, 6 deletions

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index b5c6d8eb7e03..d4db3b6f4b8e 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -553,23 +553,41 @@ static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 	return err;
 }
 
-static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
-			    void *ptr)
+static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
 {
-	struct super_block *sb = ptr;
-	struct nfs_net *nn = net_generic(sb->s_fs_info, nfs_net_id);
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *cl_dentry;
 	struct nfs_client *clp;
-	int error = 0;
 
 	spin_lock(&nn->nfs_client_lock);
 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 		if (clp->rpc_ops != &nfs_v4_clientops)
 			continue;
+		cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
+		if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) ||
+		    ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry))
+			continue;
+		atomic_inc(&clp->cl_count);
+		spin_unlock(&nn->nfs_client_lock);
+		return clp;
+	}
+	spin_unlock(&nn->nfs_client_lock);
+	return NULL;
+}
+
+static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
+			    void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct nfs_client *clp;
+	int error = 0;
+
+	while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) {
 		error = __rpc_pipefs_event(clp, event, sb);
+		nfs_put_client(clp);
 		if (error)
 			break;
 	}
-	spin_unlock(&nn->nfs_client_lock);
 	return error;
 }