---

yaml
---
r: 158997
b: refs/heads/master
c: 02a6a25
h: refs/heads/master
i:
  158995: a3a19db
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9ddbcfa098bae757d3760dd1dbf2847a0bd5a525
+refs/heads/master: 02a6a2592e41d27644d647f3bce23598649961bc

trunk/net/rds/ib.h

@@ -358,17 +358,25 @@ extern ctl_table rds_ib_sysctl_table[];
 /*
  * Helper functions for getting/setting the header and data SGEs in
  * RDS packets (not RDMA)
+ *
+ * From version 3.1 onwards, header is in front of data in the sge.
  */
 static inline struct ib_sge *
 rds_ib_header_sge(struct rds_ib_connection *ic, struct ib_sge *sge)
 {
-	return &sge[0];
+	if (ic->conn->c_version > RDS_PROTOCOL_3_0)
+		return &sge[0];
+	else
+		return &sge[1];
 }
 
 static inline struct ib_sge *
 rds_ib_data_sge(struct rds_ib_connection *ic, struct ib_sge *sge)
 {
-	return &sge[1];
+	if (ic->conn->c_version > RDS_PROTOCOL_3_0)
+		return &sge[1];
+	else
+		return &sge[0];
 }
 
 #endif

trunk/net/rds/ib_cm.c

@@ -101,10 +101,13 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even
 	if (event->param.conn.private_data_len >= sizeof(*dp)) {
 		dp = event->param.conn.private_data;
 
-		rds_ib_set_protocol(conn,
+		/* make sure it isn't empty data */
+		if (dp->dp_protocol_major) {
+			rds_ib_set_protocol(conn,
 				RDS_PROTOCOL(dp->dp_protocol_major,
-					dp->dp_protocol_minor));
-		rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
+				dp->dp_protocol_minor));
+			rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
+		}
 	}
 
 	printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",

trunk/net/rds/ib_recv.c

@@ -555,6 +555,47 @@ u64 rds_ib_piggyb_ack(struct rds_ib_connection *ic)
 	return rds_ib_get_ack(ic);
 }
 
+static struct rds_header *rds_ib_get_header(struct rds_connection *conn,
+					    struct rds_ib_recv_work *recv,
+					    u32 data_len)
+{
+	struct rds_ib_connection *ic = conn->c_transport_data;
+	void *hdr_buff = &ic->i_recv_hdrs[recv - ic->i_recvs];
+	void *addr;
+	u32 misplaced_hdr_bytes;
+
+	/*
+	 * Support header at the front (RDS 3.1+) as well as header-at-end.
+	 *
+	 * Cases:
+	 * 1) header all in header buff (great!)
+	 * 2) header all in data page (copy all to header buff)
+	 * 3) header split across hdr buf + data page
+	 *    (move bit in hdr buff to end before copying other bit from data page)
+	 */
+	if (conn->c_version > RDS_PROTOCOL_3_0 || data_len == RDS_FRAG_SIZE)
+	        return hdr_buff;
+
+	if (data_len <= (RDS_FRAG_SIZE - sizeof(struct rds_header))) {
+		addr = kmap_atomic(recv->r_frag->f_page, KM_SOFTIRQ0);
+		memcpy(hdr_buff,
+		       addr + recv->r_frag->f_offset + data_len,
+		       sizeof(struct rds_header));
+		kunmap_atomic(addr, KM_SOFTIRQ0);
+		return hdr_buff;
+	}
+
+	misplaced_hdr_bytes = (sizeof(struct rds_header) - (RDS_FRAG_SIZE - data_len));
+
+	memmove(hdr_buff + misplaced_hdr_bytes, hdr_buff, misplaced_hdr_bytes);
+
+	addr = kmap_atomic(recv->r_frag->f_page, KM_SOFTIRQ0);
+	memcpy(hdr_buff, addr + recv->r_frag->f_offset + data_len,
+	       sizeof(struct rds_header) - misplaced_hdr_bytes);
+	kunmap_atomic(addr, KM_SOFTIRQ0);
+	return hdr_buff;
+}
+
 /*
  * It's kind of lame that we're copying from the posted receive pages into
  * long-lived bitmaps.  We could have posted the bitmaps and rdma written into
@@ -667,7 +708,7 @@ static void rds_ib_process_recv(struct rds_connection *conn,
 	}
 	byte_len -= sizeof(struct rds_header);
 
-	ihdr = &ic->i_recv_hdrs[recv - ic->i_recvs];
+	ihdr = rds_ib_get_header(conn, recv, byte_len);
 
 	/* Validate the checksum. */
 	if (!rds_message_verify_checksum(ihdr)) {