Merge tag 'regmap-3.4' into regmap-stride

regmap: Last minute bug fix for 3.4

This is a last minute bug fix that was only just noticed since the code
path that's being exercised here is one that is fairly rarely used.  The
changelog for the change itself is extremely clear and the code itself
is obvious to inspection so should be pretty safe.

Conflicts:
	drivers/base/regmap/regmap.c (overlap between the fix and stride code)

1 files changed, 39 insertions, 11 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 67972462a54..adf2990aceb 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -176,16 +176,22 @@ rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 	return 0;
 }
 
-static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
-				struct super_block *sb)
+static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
+{
+	if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
+	    ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
+		return 1;
+	return 0;
+}
+
+static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
+				   struct super_block *sb)
 {
 	struct dentry *dentry;
 	int err = 0;
 
 	switch (event) {
 	case RPC_PIPEFS_MOUNT:
-		if (clnt->cl_program->pipe_dir_name == NULL)
-			break;
 		dentry = rpc_setup_pipedir_sb(sb, clnt,
 					      clnt->cl_program->pipe_dir_name);
 		BUG_ON(dentry == NULL);
@@ -208,6 +214,20 @@ static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 	return err;
 }
 
+static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
+				struct super_block *sb)
+{
+	int error = 0;
+
+	for (;; clnt = clnt->cl_parent) {
+		if (!rpc_clnt_skip_event(clnt, event))
+			error = __rpc_clnt_handle_event(clnt, event, sb);
+		if (error || clnt == clnt->cl_parent)
+			break;
+	}
+	return error;
+}
+
 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
@@ -215,10 +235,12 @@ static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 
 	spin_lock(&sn->rpc_client_lock);
 	list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
-		if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
-		    ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
+		if (clnt->cl_program->pipe_dir_name == NULL)
+			break;
+		if (rpc_clnt_skip_event(clnt, event))
+			continue;
+		if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 			continue;
-		atomic_inc(&clnt->cl_count);
 		spin_unlock(&sn->rpc_client_lock);
 		return clnt;
 	}
@@ -257,6 +279,14 @@ void rpc_clients_notifier_unregister(void)
 	return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 }
 
+static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
+{
+	clnt->cl_nodelen = strlen(nodename);
+	if (clnt->cl_nodelen > UNX_MAXNODENAME)
+		clnt->cl_nodelen = UNX_MAXNODENAME;
+	memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
+}
+
 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 {
 	const struct rpc_program *program = args->program;
@@ -337,10 +367,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, stru
 	}
 
 	/* save the nodename */
-	clnt->cl_nodelen = strlen(init_utsname()->nodename);
-	if (clnt->cl_nodelen > UNX_MAXNODENAME)
-		clnt->cl_nodelen = UNX_MAXNODENAME;
-	memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
+	rpc_clnt_set_nodename(clnt, utsname()->nodename);
 	rpc_register_client(clnt);
 	return clnt;
 
@@ -499,6 +526,7 @@ rpc_clone_client(struct rpc_clnt *clnt)
 	err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 	if (err != 0)
 		goto out_no_path;
+	rpc_clnt_set_nodename(new, utsname()->nodename);
 	if (new->cl_auth)
 		atomic_inc(&new->cl_auth->au_count);
 	atomic_inc(&clnt->cl_count);