9P: Add memory barriers to protect request fields over cb/rpc threads handoff
We need barriers to guarantee this pattern works as intended:
[w] req->rc, 1 [r] req->status, 1
wmb rmb
[w] req->status, 1 [r] req->rc
Where the wmb ensures that rc gets written before status,
and the rmb ensures that if you observe status == 1, rc is the new value.
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index 8f68df5..f127ae5 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -305,8 +305,7 @@
}
req->rc = c->rc;
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(client, req);
+ p9_client_cb(client, req, REQ_STATUS_RCVD);
return;