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, 3 insertions, 3 deletions

diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
index 8557a1cae041..8ac80c1b051e 100644
--- a/net/rds/ib_send.c
+++ b/net/rds/ib_send.c
@@ -492,7 +492,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
 	struct rds_ib_send_work *send = NULL;
 	struct rds_ib_send_work *first;
 	struct rds_ib_send_work *prev;
-	struct ib_send_wr *failed_wr;
+	const struct ib_send_wr *failed_wr;
 	struct scatterlist *scat;
 	u32 pos;
 	u32 i;
@@ -758,7 +758,7 @@ int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op)
 {
 	struct rds_ib_connection *ic = conn->c_transport_data;
 	struct rds_ib_send_work *send = NULL;
-	struct ib_send_wr *failed_wr;
+	const struct ib_send_wr *failed_wr;
 	struct rds_ib_device *rds_ibdev;
 	u32 pos;
 	u32 work_alloc;
@@ -849,7 +849,7 @@ int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
 	struct rds_ib_send_work *send = NULL;
 	struct rds_ib_send_work *first;
 	struct rds_ib_send_work *prev;
-	struct ib_send_wr *failed_wr;
+	const struct ib_send_wr *failed_wr;
 	struct scatterlist *scat;
 	unsigned long len;
 	u64 remote_addr = op->op_remote_addr;