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

[Marc Eshel]

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


---

 fs/nfs/nfs4filelayoutdev.c |   37 +++++++++++++++++++++++++------------
 1 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index acb36fa..f1fa3fa 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -117,7 +117,15 @@ 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\n",
+			dev->dev_id, ntohl(dev->ip_addr), ntohs(dev->port));
+
+	if (PTR_ERR(clp->cl_rpcclient) != -EINVAL) {
+		dprintk("device_create: dev_id=%u got rpc client\n",
+								dev->dev_id);
+		dev->clp = clp;
+		goto out;
+	}
 
 	xprt = xprt_create_proto(IPPROTO_TCP, &sin,
 				 &mds_rpc->cl_xprt->timeout);
@@ -146,12 +154,16 @@ 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 shared with MDS jsut 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 +229,15 @@ 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);