[pnfs] [PATCH 02/11] Refactor NFSv4 callback service

[ricardo.labiaga at netapp.com]

Prepare the NFSv4 callback service mechanism to understand v4.0 and v4.1
callbacks.  Create a new function nfs4_callback_up() that contains the minor
version 0 specific logic.  It is invoked by nfs_callback_up().

Augment the list of arguments passed to nfs_callback_up() since it will need
to deal with minor version 1 as well.  Move the creation of the backchannel
after the rpc_client has been initialized since the rpc_xprt structure will be
needed to crated the NFSv4.1 callback.

Signed-off-by: Ricardo Labiaga <ricardo.labiaga at netapp.com>
---
 fs/nfs/callback.c |   35 +++++++++++++++++++++++++----------
 fs/nfs/callback.h |    2 +-
 fs/nfs/client.c   |   19 ++++++++++---------
 3 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index a796be5..2898a6b 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -57,7 +57,7 @@ module_param_call(callback_tcpport, param_set_port, param_get_int,
 /*
  * This is the callback kernel thread.
  */
-static void nfs_callback_svc(struct svc_rqst *rqstp)
+static void nfs4_callback_svc(struct svc_rqst *rqstp)
 {
 	int err;
 
@@ -104,10 +104,28 @@ static void nfs_callback_svc(struct svc_rqst *rqstp)
 	module_put_and_exit(0);
 }
 
+
+/*
+ * Bring up the NFSv4 callback service
+ */
+int nfs4_callback_up(struct svc_serv *serv) {
+	int ret = 0;
+
+	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,
+							SVC_SOCK_ANONYMOUS);
+	if (ret < 0)
+		return ret;
+	nfs_callback_tcpport = ret;
+	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
+	ret = svc_create_thread(nfs4_callback_svc, serv);
+
+	return ret;
+}
+
 /*
  * Bring up the server process if it is not already up.
  */
-int nfs_callback_up(void)
+int nfs_callback_up(int minorversion, void *args)
 {
 	struct svc_serv *serv;
 	int ret = 0;
@@ -123,14 +141,11 @@ int nfs_callback_up(void)
 	if (!serv)
 		goto out_err;
 
-	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,
-							SVC_SOCK_ANONYMOUS);
-	if (ret <= 0)
-		goto out_destroy;
-	nfs_callback_tcpport = ret;
-	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
-
-	ret = svc_create_thread(nfs_callback_svc, serv);
+	switch (minorversion) {
+	case 0:
+		ret = nfs4_callback_up(serv);
+		break;
+	}
 	if (ret < 0)
 		goto out_destroy;
 	nfs_callback_info.serv = serv;
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index c2bb14e..be1d755 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -63,7 +63,7 @@ extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getat
 extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy);
 
 #ifdef CONFIG_NFS_V4
-extern int nfs_callback_up(void);
+extern int nfs_callback_up(int minorversion, void *args);
 extern void nfs_callback_down(void);
 #else
 #define nfs_callback_up()	(0)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index dee739c..8266178 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -113,12 +113,6 @@ static struct nfs_client *nfs_alloc_client(const char *hostname,
 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
 		goto error_0;
 
-	if (nfsversion == 4) {
-		if (nfs_callback_up() < 0)
-			goto error_2;
-		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
-	}
-
 	atomic_set(&clp->cl_count, 1);
 	clp->cl_cons_state = NFS_CS_INITING;
 
@@ -150,7 +144,6 @@ static struct nfs_client *nfs_alloc_client(const char *hostname,
 error_3:
 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
 		nfs_callback_down();
-error_2:
 	kfree(clp);
 error_0:
 	return NULL;
@@ -909,14 +902,22 @@ static int nfs4_init_client(struct nfs_client *clp,
 	if (error)
 		goto error;
 
-	/* XXX TODO: Need to start the callback server here */
-
 	error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour,
 					RPC_CLNT_CREATE_DISCRTRY);
 	if (error < 0)
 		goto error;
 	memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
 
+	/* Start the callback server */
+	error = nfs_callback_up(clp->cl_minorversion,
+		clp->cl_rpcclient->cl_xprt);
+	if (error < 0) {
+		dprintk("%s: failed to start callback. Error = %d\n",
+			__FUNCTION__, error);
+		goto error;
+	}
+	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
+
 	error = nfs_idmap_new(clp);
 	if (error < 0) {
 		dprintk("%s: failed to create idmapper. Error = %d\n",
-- 
1.5.2