[pnfs] [PATCH] share one session for mds and ds

[Marc Eshel]

From: Marc Eshel <eshel at almaden.ibm.com>

This is a temporary fix to allow for the MDS and DS to be on the same
machine and share a session. There are still problem on the second mount,
some fields are not cleaned/reset properly after the first umount.
---

 fs/nfs/nfs4filelayoutdev.c |   54 ++++++++++++++++++++++++++------------------
 1 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index acb36fa..8861f4f 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -117,19 +117,24 @@ device_create(struct nfs_server *server,
 		goto out;
 	}
 
-	dprintk("device_create: dev_id=%u, ip=%x, port=%hu\n", dev->dev_id, ntohl(dev->ip_addr), ntohs(dev->port));
+	dprintk("device_create: dev_id=%u, ip=%x, port=%hu, rpcclient %p\n",
+		dev->dev_id, ntohl(dev->ip_addr), ntohs(dev->port), clp->cl_rpcclient);
 
-	xprt = xprt_create_proto(IPPROTO_TCP, &sin,
-				 &mds_rpc->cl_xprt->timeout);
-	if (IS_ERR(xprt)) {
-		err = PTR_ERR(xprt);
-		goto out;
-	}
+	if (PTR_ERR(clp->cl_rpcclient) == -EINVAL || clp->cl_rpcclient == NULL)
+	{
+		xprt = xprt_create_proto(IPPROTO_TCP, &sin,
+					 &mds_rpc->cl_xprt->timeout);
+		if (IS_ERR(xprt)) {
+			err = PTR_ERR(xprt);
+			goto out;
+		}
 
-	clp->cl_rpcclient = create_nfs_rpcclient(xprt, "nfs4_pnfs_dserver", mds_rpc->cl_vers, mds_rpc->cl_auth->au_flavor, &err);
-	if (clp->cl_rpcclient == NULL) {
-		printk("%s: Can't create nfs rpc client!\n", __FUNCTION__);
-		goto out;
+		clp->cl_rpcclient = create_nfs_rpcclient(xprt, "nfs4_pnfs_dserver", mds_rpc->cl_vers, mds_rpc->cl_auth->au_flavor, &err);
+		if (clp->cl_rpcclient == NULL) {
+			printk("%s: Can't create nfs rpc client!\n",
+								__FUNCTION__);
+			goto out;
+		}
 	}
 
 	dev->clp = clp;
@@ -146,12 +151,16 @@ device_destroy(struct nfs4_pnfs_dev_item
 	if (!dev)
 		return;
 
-	if ((status = _nfs4_proc_destroy_session(&dev->clp->cl_session, dev->clp->cl_rpcclient)))
-		printk(KERN_WARNING "destroy session on data server failed with status %d...\
+	/* if not created for DS just return */
+	if (dev->clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS) {
+
+		if ((status = _nfs4_proc_destroy_session(&dev->clp->cl_session, dev->clp->cl_rpcclient)))
+			printk(KERN_WARNING "destroy session on data server failed with status %d...\
 				 blowing away device anyways!\n", status);
 
-	/*	BUG_ON(!atomic_sub_and_test(0, &dev->count)); */
-	rpc_shutdown_client(dev->clp->cl_rpcclient);
+		/*	BUG_ON(!atomic_sub_and_test(0, &dev->count)); */
+		rpc_shutdown_client(dev->clp->cl_rpcclient);
+	}
 
 	kfree(dev);
 }
@@ -217,14 +226,15 @@ nfs4_pnfs_device_add(struct filelayout_m
 		return err;
 	}
 
-	/* Set exchange id and create session flags */
-	dev->clp->cl_session_flags = 0;
-	dev->clp->cl_exchange_flags = EXCHGID4_FLAG_USE_PNFS_DS;
-
-	err = server->rpc_ops->setup_session(dev->clp);
-	if (err)
-		return err;
+	if (dev->clp->cl_session == NULL) {
+		/* Set exchange id and create session flags */
+		dev->clp->cl_session_flags = 0;
+		dev->clp->cl_exchange_flags = EXCHGID4_FLAG_USE_PNFS_DS;
 
+		err = server->rpc_ops->setup_session(dev->clp);
+		if (err)
+			return err;
+        }
 	/* Write lock, do lookup again, and then add device */
 	write_lock(&hlist->dev_lock);
 	tmp_dev = _device_lookup(hlist, dev->dev_id);