[PATCH v3 2/2] RDS: fix congestion map corruption for PAGE_SIZE > 8k

[Shamir Rabinovitch <shamir.rabinovitch@oracle.com>]

On Sparc64 page size is 8k. So single page contain 2 RDS fragments. If
'rds_ib_cong_recv' ignore the RDS fragment offset in to the page it then
read the data fragment as far congestion map update and lead to
corruption of the RDS connection far congestion map.

This patch require the below patch for Sparc64 platforms:
001f8f8 RDS: fix "Kernel unaligned access" on sparc64

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>

Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Tested-by: Anand Bibhuti <anand.bibhuti@oracle.com>
---
 net/rds/ib_recv.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 977fb86..abc8cc8 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -796,7 +796,7 @@ static void rds_ib_cong_recv(struct rds_connection *conn,
 
 		addr = kmap_atomic(sg_page(&frag->f_sg));
 
-		src = addr + frag_off;
+		src = addr + frag->f_sg.offset + frag_off;
 		dst = (void *)map->m_page_addrs[map_page] + map_off;
 		for (k = 0; k < to_copy; k += 8) {
 			/* Record ports that became uncongested, ie
-- 
1.7.1