[PATCH 4.19 177/264] svcrdma: fix bounce buffers for unaligned offsets and multiple pages

Greg Kroah-Hartman
2020-10-27T14:25:23Z

From: Dan Aloni <dan@kernelim.com>

[ Upstream commit c327a310ec4d6ecbea13185ed56c11def441d9ab ]

This was discovered using O_DIRECT at the client side, with small
unaligned file offsets or IOs that span multiple file pages.

Fixes: e248aa7be86 ("svcrdma: Remove max_sge check at connect time")
Signed-off-by: Dan Aloni <dan@kernelim.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index aa4d19a780d78..4062cd624b26f 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -639,10 +639,11 @@ static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma,
while (remaining) {
len = min_t(u32, PAGE_SIZE - pageoff, remaining);

- memcpy(dst, page_address(*ppages), len);
+ memcpy(dst, page_address(*ppages) + pageoff, len);
remaining -= len;
dst += len;
pageoff = 0;
+ ppages++;
}
}

--
2.25.1