From cc6e3690b18236068b9bb1c94cdfc6180cef3630 Mon Sep 17 00:00:00 2001
From: "Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>
Date: Sun, 13 Feb 2011 16:23:59 -0800
Subject: [PATCH] --- yaml --- r: 235015 b: refs/heads/master c:
 1fc52481c2b886c445bb167dfd16ee6de6922ef7 h: refs/heads/master i:   235013:
 353a140ae7434697f2f2f527ddec5cba57ed5b98   235011:
 d86200239126502f0be8d444a25d87f8fb1ec934   235007:
 f469f1f10ad75d106cb803031a0192b98ed62495 v: v3

---
 [refs]                |  2 +-
 trunk/net/9p/client.c | 21 +++++++++++++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index e554960b8675..18c15d3b9457 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bb2f8a55153ec58e66a496224504ac9be919c8f1
+refs/heads/master: 1fc52481c2b886c445bb167dfd16ee6de6922ef7
diff --git a/trunk/net/9p/client.c b/trunk/net/9p/client.c
index 82079f902f56..412c52e1de74 100644
--- a/trunk/net/9p/client.c
+++ b/trunk/net/9p/client.c
@@ -1333,12 +1333,21 @@ p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
 
 	if (count < rsize)
 		rsize = count;
-	if (data)
-		req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
-								rsize, data);
-	else
-		req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
-								rsize, udata);
+
+	/* Don't bother zerocopy form small IO (< 1024) */
+	if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
+				P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
+		req = p9_client_rpc(clnt, P9_TWRITE, "dqE", fid->fid, offset,
+				rsize, data, udata);
+	} else {
+
+		if (data)
+			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
+					offset, rsize, data);
+		else
+			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
+					offset, rsize, udata);
+	}
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;