[PATCH v2 03/12] NFS: move per-net callback thread initialization to nfs_callback_up_net()

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

This new function in now called before nfs_minorversion_callback_svc_setup()).

Also few small changes:
1) current network namespace in nfs_callback_up() was replaced by transport net.
2) svc_shutdown_net() was moved prior to callback usage counter decrement
(because in case of per-net data allocation faulure svc_shutdown_net() have to
be skipped).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
---
 fs/nfs/callback.c |  125 +++++++++++++++++++++++++++++++++--------------------
 1 files changed, 78 insertions(+), 47 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index b34ccc6..2ecea36 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -64,6 +64,32 @@ static struct kernel_param_ops param_ops_portnr = {
 
 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
 
+static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
+{
+	int ret;
+
+	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
+				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
+	if (ret <= 0)
+		goto out_err;
+	nfs_callback_tcpport = ret;
+	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
+			nfs_callback_tcpport, PF_INET, net);
+
+	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
+				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
+	if (ret > 0) {
+		nfs_callback_tcpport6 = ret;
+		dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
+				nfs_callback_tcpport6, PF_INET6, net);
+	} else if (ret != -EAFNOSUPPORT)
+		goto out_err;
+	return 0;
+
+out_err:
+	return (ret) ? ret : -ENOMEM;
+}
+
 /*
  * This is the NFSv4 callback kernel thread.
  */
@@ -105,36 +131,21 @@ nfs4_callback_svc(void *vrqstp)
 static struct svc_rqst *
 nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
 {
-	int ret;
-
-	ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET,
-				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
-	if (ret <= 0)
-		goto out_err;
-	nfs_callback_tcpport = ret;
-	dprintk("NFS: Callback listener port = %u (af %u)\n",
-			nfs_callback_tcpport, PF_INET);
-
-	ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET6,
-				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
-	if (ret > 0) {
-		nfs_callback_tcpport6 = ret;
-		dprintk("NFS: Callback listener port = %u (af %u)\n",
-				nfs_callback_tcpport6, PF_INET6);
-	} else if (ret == -EAFNOSUPPORT)
-		ret = 0;
-	else
-		goto out_err;
-
 	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-
-out_err:
-	if (ret == 0)
-		ret = -ENOMEM;
-	return ERR_PTR(ret);
 }
 
 #if defined(CONFIG_NFS_V4_1)
+static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
+{
+	/*
+	 * Create an svc_sock for the back channel service that shares the
+	 * fore channel connection.
+	 * Returns the input port (0) and sets the svc_serv bc_xprt on success
+	 */
+	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
+			      SVC_SOCK_ANONYMOUS);
+}
+
 /*
  * The callback service for NFSv4.1 callbacks
  */
@@ -177,19 +188,6 @@ static struct svc_rqst *
 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
 {
 	struct svc_rqst *rqstp;
-	int ret;
-
-	/*
-	 * Create an svc_sock for the back channel service that shares the
-	 * fore channel connection.
-	 * Returns the input port (0) and sets the svc_serv bc_xprt on success
-	 */
-	ret = svc_create_xprt(serv, "tcp-bc", xprt->xprt_net, PF_INET, 0,
-			      SVC_SOCK_ANONYMOUS);
-	if (ret < 0) {
-		rqstp = ERR_PTR(ret);
-		goto out;
-	}
 
 	/*
 	 * Save the svc_serv in the transport so that it can
@@ -205,7 +203,6 @@ nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
 		svc_xprt_put(serv->sv_bc_xprt);
 		serv->sv_bc_xprt = NULL;
 	}
-out:
 	dprintk("--> %s return %ld\n", __func__,
 		IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
 	return rqstp;
@@ -229,6 +226,11 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 		xprt->bc_serv = cb_info->serv;
 }
 #else
+static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
+{
+	return 0;
+}
+
 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
 		struct svc_serv *serv, struct rpc_xprt *xprt,
 		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
@@ -242,6 +244,36 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 }
 #endif /* CONFIG_NFS_V4_1 */
 
+static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
+{
+	int ret;
+
+	dprintk("NFS: create per-net callback data; net=%p\n", net);
+
+	ret = svc_bind(serv, net);
+	if (ret < 0) {
+		printk(KERN_WARNING "NFS: bind callback service failed\n");
+		goto err_bind;
+	}
+
+	if (minorversion) {
+		ret = nfs41_callback_up_net(serv, net);
+		if (ret < 0)
+			goto err_socks;
+	}
+
+	if (ret == 0)
+		ret = nfs4_callback_up_net(serv, net);
+	if (ret < 0)
+		goto err_socks;
+	return 0;
+
+err_socks:
+	svc_rpcb_cleanup(serv, net);
+err_bind:
+	return ret;
+}
+
 static struct svc_serv *nfs_callback_create_svc(int minorversion)
 {
 	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
@@ -288,7 +320,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	char svc_name[12];
 	int ret = 0;
 	int minorversion_setup;
-	struct net *net = current->nsproxy->net_ns;
+	struct net *net = xprt->xprt_net;
 
 	mutex_lock(&nfs_callback_mutex);
 
@@ -303,11 +335,9 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 		goto out;
 	}
 
-	ret = svc_bind(serv, net);
-	if (ret < 0) {
-		printk(KERN_WARNING "NFS: bind callback service failed\n");
-		goto out_err;
-	}
+	ret = nfs_callback_up_net(minorversion, serv, net);
+	if (ret < 0)
+		goto err_net;
 
 	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
 					serv, xprt, &rqstp, &callback_svc);
@@ -347,10 +377,11 @@ err_create:
 	mutex_unlock(&nfs_callback_mutex);
 	return ret;
 out_err:
+	svc_shutdown_net(serv, net);
+err_net:
 	dprintk("NFS: Couldn't create callback socket or server thread; "
 		"err = %d\n", ret);
 	cb_info->users--;
-	svc_shutdown_net(serv, net);
 	goto out;
 }