SUNRPC: Convert auth_gss pipe detection to work in namespaces

This seems to have been overlooked when we did the namespace
conversion. If a container is running a legacy version of rpc.gssd
then it will be disrupted if the global 'pipe_version' is set by a
container running the new version of rpc.gssd.

Signed-off-by: Trond Myklebust <[e-mail]>

net/sunrpc/auth_gss/auth_gss.c

···
 };
 
 /* pipe_version >= 0 if and only if someone has a pipe open. */
-static int pipe_version = -1;
-static atomic_t pipe_users = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(pipe_version_lock);
 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
···
 	char databuf[UPCALL_BUF_LEN];
 };
 
-static int get_pipe_version(void)
+static int get_pipe_version(struct net *net)
 {
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	int ret;
 
 	spin_lock(&pipe_version_lock);
-	if (pipe_version >= 0) {
-		atomic_inc(&pipe_users);
-		ret = pipe_version;
+	if (sn->pipe_version >= 0) {
+		atomic_inc(&sn->pipe_users);
+		ret = sn->pipe_version;
 	} else
 		ret = -EAGAIN;
 	spin_unlock(&pipe_version_lock);
 	return ret;
 }
 
-static void put_pipe_version(void)
+static void put_pipe_version(struct net *net)
 {
-	if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
-		pipe_version = -1;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
+		sn->pipe_version = -1;
 		spin_unlock(&pipe_version_lock);
 	}
 }
···
 static void
 gss_release_msg(struct gss_upcall_msg *gss_msg)
 {
+	struct net *net = rpc_net_ns(gss_msg->auth->client);
 	if (!atomic_dec_and_test(&gss_msg->count))
 		return;
-	put_pipe_version();
+	put_pipe_version(net);
 	BUG_ON(!list_empty(&gss_msg->list));
 	if (gss_msg->ctx != NULL)
 		gss_put_ctx(gss_msg->ctx);
···
 				struct rpc_clnt *clnt,
 				const char *service_name)
 {
-	if (pipe_version == 0)
+	struct net *net = rpc_net_ns(clnt);
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (sn->pipe_version == 0)
 		gss_encode_v0_msg(gss_msg);
 	else /* pipe_version == 1 */
 		gss_encode_v1_msg(gss_msg, clnt, service_name);
···
 	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 	if (gss_msg == NULL)
 		return ERR_PTR(-ENOMEM);
-	vers = get_pipe_version();
+	vers = get_pipe_version(rpc_net_ns(clnt));
 	if (vers < 0) {
 		kfree(gss_msg);
 		return ERR_PTR(vers);
···
 	gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 	if (PTR_ERR(gss_msg) == -EAGAIN) {
 		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
-				pipe_version >= 0, timeout);
-		if (pipe_version < 0) {
+				sn->pipe_version >= 0, timeout);
+		if (sn->pipe_version < 0) {
 			if (err == 0)
 				sn->gssd_running = 0;
 			warn_gssd();
···
 
 static int gss_pipe_open(struct inode *inode, int new_version)
 {
+	struct net *net = inode->i_sb->s_fs_info;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	int ret = 0;
 
 	spin_lock(&pipe_version_lock);
-	if (pipe_version < 0) {
+	if (sn->pipe_version < 0) {
 		/* First open of any gss pipe determines the version: */
-		pipe_version = new_version;
+		sn->pipe_version = new_version;
 		rpc_wake_up(&pipe_version_rpc_waitqueue);
 		wake_up(&pipe_version_waitqueue);
-	} else if (pipe_version != new_version) {
+	} else if (sn->pipe_version != new_version) {
 		/* Trying to open a pipe of a different version */
 		ret = -EBUSY;
 		goto out;
 	}
-	atomic_inc(&pipe_users);
+	atomic_inc(&sn->pipe_users);
 out:
 	spin_unlock(&pipe_version_lock);
 	return ret;
···
 static void
 gss_pipe_release(struct inode *inode)
 {
+	struct net *net = inode->i_sb->s_fs_info;
 	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 	struct gss_upcall_msg *gss_msg;
 
···
 	}
 	spin_unlock(&pipe->lock);
 
-	put_pipe_version();
+	put_pipe_version(net);
 }
 
 static void

net/sunrpc/netns.h

···
 	wait_queue_head_t gssp_wq;
 	struct rpc_clnt *gssp_clnt;
 	int use_gss_proxy;
+	int pipe_version;
+	atomic_t pipe_users;
 	struct proc_dir_entry *use_gssp_proc;
 
 	unsigned int gssd_running;

net/sunrpc/rpc_pipe.c

···
 
 	mutex_init(&sn->pipefs_sb_lock);
 	sn->gssd_running = 1;
+	sn->pipe_version = -1;
 }
 
 /*