[PATCH] RDMA/bnxt_re: Drop unnecessary NULL checks after container_of

[PATCH] RDMA/bnxt_re: Drop unnecessary NULL checks after container_of

[Guenter Roeck]

The result of container_of() operations is never NULL unless the first
element of the embedding structure is extracted. This is either not the
case here, or the pointer passed to container_of() is known to be not
NULL. The NULL checks are therefore unnecessary and misleading.
Remove them.

The channges in this patch were made automatically with the following
Coccinelle script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
  t v = container_of(...);
|
  v = container_of(...);
)
  ...
  when != v
- if (\( !v \| v == NULL \) ) s
...+>

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/infiniband/hw/bnxt_re/ib_verbs.c | 18 ------------------
 drivers/infiniband/hw/bnxt_re/main.c     | 12 ------------
 2 files changed, 30 deletions(-)

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index 2efaa80bfbd2..537471ffaa79 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -1098,10 +1098,6 @@ static int bnxt_re_init_rq_attr(struct bnxt_re_qp *qp,
 		struct bnxt_re_srq *srq;
 
 		srq = container_of(init_attr->srq, struct bnxt_re_srq, ib_srq);
-		if (!srq) {
-			ibdev_err(&rdev->ibdev, "SRQ not found");
-			return -EINVAL;
-		}
 		qplqp->srq = &srq->qplib_srq;
 		rq->max_wqe = 0;
 	} else {
@@ -1279,22 +1275,12 @@ static int bnxt_re_init_qp_attr(struct bnxt_re_qp *qp, struct bnxt_re_pd *pd,
 	/* Setup CQs */
 	if (init_attr->send_cq) {
 		cq = container_of(init_attr->send_cq, struct bnxt_re_cq, ib_cq);
-		if (!cq) {
-			ibdev_err(&rdev->ibdev, "Send CQ not found");
-			rc = -EINVAL;
-			goto out;
-		}
 		qplqp->scq = &cq->qplib_cq;
 		qp->scq = cq;
 	}
 
 	if (init_attr->recv_cq) {
 		cq = container_of(init_attr->recv_cq, struct bnxt_re_cq, ib_cq);
-		if (!cq) {
-			ibdev_err(&rdev->ibdev, "Receive CQ not found");
-			rc = -EINVAL;
-			goto out;
-		}
 		qplqp->rcq = &cq->qplib_cq;
 		qp->rcq = cq;
 	}
@@ -3473,10 +3459,6 @@ int bnxt_re_poll_cq(struct ib_cq *ib_cq, int num_entries, struct ib_wc *wc)
 				((struct bnxt_qplib_qp *)
 				 (unsigned long)(cqe->qp_handle),
 				 struct bnxt_re_qp, qplib_qp);
-			if (!qp) {
-				ibdev_err(&cq->rdev->ibdev, "POLL CQ : bad QP handle");
-				continue;
-			}
 			wc->qp = &qp->ib_qp;
 			wc->ex.imm_data = cqe->immdata;
 			wc->src_qp = cqe->src_qp;
diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c
index 8bfbf0231a9e..b090dfa4f4cb 100644
--- a/drivers/infiniband/hw/bnxt_re/main.c
+++ b/drivers/infiniband/hw/bnxt_re/main.c
@@ -885,12 +885,6 @@ static int bnxt_re_srqn_handler(struct bnxt_qplib_nq *nq,
 	struct ib_event ib_event;
 	int rc = 0;
 
-	if (!srq) {
-		ibdev_err(NULL, "%s: SRQ is NULL, SRQN not handled",
-			  ROCE_DRV_MODULE_NAME);
-		rc = -EINVAL;
-		goto done;
-	}
 	ib_event.device = &srq->rdev->ibdev;
 	ib_event.element.srq = &srq->ib_srq;
 	if (event == NQ_SRQ_EVENT_EVENT_SRQ_THRESHOLD_EVENT)
@@ -903,7 +897,6 @@ static int bnxt_re_srqn_handler(struct bnxt_qplib_nq *nq,
 		(*srq->ib_srq.event_handler)(&ib_event,
 					     srq->ib_srq.srq_context);
 	}
-done:
 	return rc;
 }
 
@@ -913,11 +906,6 @@ static int bnxt_re_cqn_handler(struct bnxt_qplib_nq *nq,
 	struct bnxt_re_cq *cq = container_of(handle, struct bnxt_re_cq,
 					     qplib_cq);
 
-	if (!cq) {
-		ibdev_err(NULL, "%s: CQ is NULL, CQN not handled",
-			  ROCE_DRV_MODULE_NAME);
-		return -EINVAL;
-	}
 	if (cq->ib_cq.comp_handler) {
 		/* Lock comp_handler? */
 		(*cq->ib_cq.comp_handler)(&cq->ib_cq, cq->ib_cq.cq_context);
-- 
2.25.1

Re: [PATCH] RDMA/bnxt_re: Drop unnecessary NULL checks after container_of

[Jason Gunthorpe]

On Fri, May 14, 2021 at 08:36:06AM -0700, Guenter Roeck wrote:
> The result of container_of() operations is never NULL unless the first
> element of the embedding structure is extracted. This is either not the
> case here, or the pointer passed to container_of() is known to be not
> NULL. The NULL checks are therefore unnecessary and misleading.
> Remove them.
> 
> The channges in this patch were made automatically with the following
> Coccinelle script.
> 
> @@
> type t;
> identifier v;
> statement s;
> @@
> 
> <+...
> (
>   t v = container_of(...);
> |
>   v = container_of(...);
> )
>   ...
>   when != v
> - if (\( !v \| v == NULL \) ) s
> ...+>
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/infiniband/hw/bnxt_re/ib_verbs.c | 18 ------------------
>  drivers/infiniband/hw/bnxt_re/main.c     | 12 ------------
>  2 files changed, 30 deletions(-)

Applied to for-next, thanks

Jason