RDMA, core and ULPs: Declare ib_post_send() and ib_post_recv() arguments const

Since neither ib_post_send() nor ib_post_recv() modify the data structure
their second argument points at, declare that argument const. This change
makes it necessary to declare the 'bad_wr' argument const too and also to
modify all ULPs that call ib_post_send(), ib_post_recv() or
ib_post_srq_recv(). This patch does not change any functionality but makes
it possible for the compiler to verify whether the
ib_post_(send|recv|srq_recv) really do not modify the posted work request.

To make this possible, only one cast had to be introduce that casts away
constness, namely in rpcrdma_post_recvs(). The only way I can think of to
avoid that cast is to introduce an additional loop in that function or to
change the data type of bad_wr from struct ib_recv_wr ** into int
(an index that refers to an element in the work request list). However,
both approaches would require even more extensive changes than this
patch.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/usnic/usnic_ib_verbs.h b/drivers/infiniband/hw/usnic/usnic_ib_verbs.h
index 1fda94425116..2a2c9beb715f 100644
--- a/drivers/infiniband/hw/usnic/usnic_ib_verbs.h
+++ b/drivers/infiniband/hw/usnic/usnic_ib_verbs.h
@@ -80,10 +80,10 @@ struct ib_ah *usnic_ib_create_ah(struct ib_pd *pd,
 				 struct ib_udata *udata);
 
 int usnic_ib_destroy_ah(struct ib_ah *ah);
-int usnic_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
-			struct ib_send_wr **bad_wr);
-int usnic_ib_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
-			struct ib_recv_wr **bad_wr);
+int usnic_ib_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+			const struct ib_send_wr **bad_wr);
+int usnic_ib_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		       const struct ib_recv_wr **bad_wr);
 int usnic_ib_poll_cq(struct ib_cq *ibcq, int num_entries,
 			struct ib_wc *wc);
 int usnic_ib_req_notify_cq(struct ib_cq *cq,