[PATCH v4 03/10] NFS: move per-net callback thread initialization to nfs_callback_up_net()

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

v4:
1) Callback transport creation routine selection by version simlified.

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   |  133 +++++++++++++++++++++++++++++++++------------------
 fs/nfs/nfs4client.c |    2 -
 2 files changed, 87 insertions(+), 48 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 18efeb5..a53b4e5 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -39,6 +39,32 @@ static struct svc_program nfs4_callback_program;
 
 unsigned short nfs_callback_tcpport6;
 
+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.
  */
@@ -80,36 +106,21 @@ 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", &init_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", &init_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
  */
@@ -152,19 +163,6 @@ 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", &init_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
@@ -180,7 +178,6 @@ 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;
@@ -204,6 +201,11 @@ 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))
@@ -217,6 +219,44 @@ 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;
+	}
+
+	switch (minorversion) {
+		case 0:
+			ret = nfs4_callback_up_net(serv, net);
+			break;
+		case 1:
+			ret = nfs41_callback_up_net(serv, net);
+			break;
+		default:
+			printk(KERN_ERR "NFS: unknown callback version: %d\n",
+					minorversion);
+			ret = -EINVAL;
+			break;
+	}
+
+	if (ret < 0) {
+		printk(KERN_ERR "NFS: callback service start failed\n");
+		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];
@@ -267,7 +307,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	char svc_name[12];
 	int ret = 0;
 	int minorversion_setup;
-	struct net *net = &init_net;
+	struct net *net = xprt->xprt_net;
 
 	mutex_lock(&nfs_callback_mutex);
 
@@ -282,11 +322,9 @@ 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);
@@ -326,10 +364,11 @@ 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;
 }
 
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 1dfaa13..a89aebb 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -85,7 +85,7 @@ error:
 static void nfs4_destroy_callback(struct nfs_client *clp)
 {
 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
-		nfs_callback_down(clp->cl_mvops->minor_version, &init_net);
+		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
 }
 
 static void nfs4_shutdown_client(struct nfs_client *clp)