[pnfs] [PATCH 15/23] 2.6-latest pnfs client implement rpc pnfs4_read_done

[andros at umich.edu]

From: Andy Adamson <andros at umich.edu>

pnfs4_read_done is called in the rpc_call_done path used by rpc communication
to the MDS or to a filelayout data server.
Switch on MDS or Data server processing on the presence of
nfs_read_data->ds_nfs_client.

Signed-off by: Andy Adamson<andros at umich.edu>
---
 fs/nfs/nfs4proc.c |   38 ++++++++++++++++++++++++++++++++++++--
 1 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 12368d6..c6d1bbd 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2933,9 +2933,43 @@ static int nfs4_read_done(struct rpc_task *task, struct nfs_read_data *data)
 }
 
 #ifdef CONFIG_PNFS
+/*
+ * rpc_call_done callback for a read to the MDS or to a filelayout Data Server
+ */
 static int pnfs4_read_done(struct rpc_task *task, struct nfs_read_data *data)
 {
-	/* XXX Needs to be implemented */
+	struct nfs_server *mds_svr = NFS_SERVER(data->inode);
+	struct nfs4_session *session = mds_svr->session;
+	struct nfs_client *client = mds_svr->nfs_client;
+	int status;
+
+	dprintk("--> %s\n", __func__);
+	status = task->tk_status >= 0 ? 0 : task->tk_status;
+
+	/* Is this a DS session */
+	if (data->ds_nfs_client) {
+		dprintk("%s DS read\n",__func__);
+		session = data->ds_nfs_client->cl_ds_session;
+		client = NULL; /* do not update mds lease...*/
+	}
+
+	nfs41_sequence_done(client, session, &data->res.seq_res, status);
+
+	/*
+	* Handle async errors for both data servers and MDS communication.
+	*/
+
+	if (nfs4_async_handle_error(task, mds_svr, client) == -EAGAIN) {
+		rpc_restart_call(task);
+		dprintk("<-- %s status= %d\n", __FUNCTION__, -EAGAIN);
+		return -EAGAIN;
+	}
+
+	/* Only renew lease if this was a read call to MDS */
+	if (task->tk_status > 0 && !data->ds_nfs_client)
+		renew_lease(mds_svr, data->timestamp);
+
+	dprintk("<-- %s\n", __func__);
 
 	return 0;
 }
@@ -5257,7 +5291,7 @@ const struct nfs_rpc_ops pnfs_v41_clientops = {
 	.set_capabilities = nfs4_server_capabilities,
 	.decode_dirent	= nfs4_decode_dirent,
 	.read_setup	= nfs4_proc_read_setup,
-	.read_done	= nfs4_read_done,
+	.read_done	= pnfs4_read_done,
 	.write_setup	= nfs4_proc_write_setup,
 	.write_done	= nfs4_write_done,
 	.commit_setup	= nfs4_proc_commit_setup,
-- 
1.5.0.2