On Sat, Jan 25, 2020 at 11:16 PM Jason Gunthorpe <jgg@xxxxxxxxxxxx> wrote:
>
> On Fri, Jan 24, 2020 at 12:52:39AM -0500, Devesh Sharma wrote:
> > +static int bnxt_re_destroy_gsi_sqp(struct bnxt_re_qp *qp)
> > +{
> > + struct bnxt_re_qp *gsi_sqp;
> > + struct bnxt_re_ah *gsi_sah;
> > + struct bnxt_re_dev *rdev;
> > + int rc = 0;
> > +
> > + rdev = qp->rdev;
> > + gsi_sqp = rdev->gsi_ctx.gsi_sqp;
> > + gsi_sah = rdev->gsi_ctx.gsi_sah;
> > +
> > + /* remove from active qp list */
> > + mutex_lock(&rdev->qp_lock);
> > + list_del(&gsi_sqp->list);
> > + atomic_dec(&rdev->qp_count);
> > + mutex_unlock(&rdev->qp_lock);
> > +
> > + dev_dbg(rdev_to_dev(rdev), "Destroy the shadow AH\n");
> > + bnxt_qplib_destroy_ah(&rdev->qplib_res,
> > + &gsi_sah->qplib_ah,
> > + true);
> > + bnxt_qplib_clean_qp(&qp->qplib_qp);
> > +
> > + dev_dbg(rdev_to_dev(rdev), "Destroy the shadow QP\n");
> > + rc = bnxt_qplib_destroy_qp(&rdev->qplib_res, &gsi_sqp->qplib_qp);
> > + if (rc) {
> > + dev_err(rdev_to_dev(rdev), "Destroy Shadow QP failed");
> > + goto fail;
> > + }
> > + bnxt_qplib_free_qp_res(&rdev->qplib_res, &gsi_sqp->qplib_qp);
> > +
> > + kfree(rdev->gsi_ctx.sqp_tbl);
> > + kfree(gsi_sah);
> > + kfree(gsi_sqp);
> > + rdev->gsi_ctx.gsi_sqp = NULL;
> > + rdev->gsi_ctx.gsi_sah = NULL;
> > + rdev->gsi_ctx.sqp_tbl = NULL;
> > +
> > + return 0;
> > +fail:
> > + mutex_lock(&rdev->qp_lock);
> > + list_add_tail(&gsi_sqp->list, &rdev->qp_list);
> > + atomic_inc(&rdev->qp_count);
> > + mutex_unlock(&rdev->qp_lock);
> > + return rc;
>
> This error unwind approach looks racy. destroy is not allowed to
> fail, so why all this mess?
True, the unwind is not required, even if the driver wants to keep it
for debugging purpose, the zombie resource would give rise to
confusion.
>
> > /* Queue Pairs */
> > int bnxt_re_destroy_qp(struct ib_qp *ib_qp, struct ib_udata *udata)
> > {
> > @@ -750,10 +797,18 @@ int bnxt_re_destroy_qp(struct ib_qp *ib_qp, struct ib_udata *udata)
> > unsigned int flags;
> > int rc;
> >
> > + mutex_lock(&rdev->qp_lock);
> > + list_del(&qp->list);
> > + atomic_dec(&rdev->qp_count);
> > + mutex_unlock(&rdev->qp_lock);
> > bnxt_qplib_flush_cqn_wq(&qp->qplib_qp);
> > rc = bnxt_qplib_destroy_qp(&rdev->qplib_res, &qp->qplib_qp);
> > if (rc) {
> > dev_err(rdev_to_dev(rdev), "Failed to destroy HW QP");
> > + mutex_lock(&rdev->qp_lock);
> > + list_add_tail(&qp->list, &rdev->qp_list);
> > + atomic_inc(&rdev->qp_count);
> > + mutex_unlock(&rdev->qp_lock);
> > return rc;
> > }
>
> More..
Let me see if I can remove it in this series, else future series would
remove it.
>
> Jason
