RDMA/core: Properly increment and decrement QP usecnts

The QP usecnts were incremented through QP attributes structure while
decreased through QP itself. Rely on the ib_creat_qp_user() code that
initialized all QP parameters prior returning to the user and increment
exactly like destroy does.

Link: https://lore.kernel.org/r/25d256a3bb1fc480b77d7fe439817b993de48610.1628014762.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/core_priv.h

@@ -320,6 +320,8 @@ struct ib_qp *_ib_create_qp(struct ib_device *dev, struct ib_pd *pd,
 			    struct ib_qp_init_attr *attr,
 			    struct ib_udata *udata, struct ib_uqp_object *uobj,
 			    const char *caller);
+void ib_qp_usecnt_inc(struct ib_qp *qp);
+void ib_qp_usecnt_dec(struct ib_qp *qp);
 
 struct rdma_dev_addr;
 int rdma_resolve_ip_route(struct sockaddr *src_addr,

drivers/infiniband/core/uverbs_cmd.c

@@ -1445,18 +1445,9 @@ static int create_qp(struct uverbs_attr_bundle *attrs,
 		ret = PTR_ERR(qp);
 		goto err_put;
 	}
+	ib_qp_usecnt_inc(qp);
 
-	if (cmd->qp_type != IB_QPT_XRC_TGT) {
+	if (cmd->qp_type == IB_QPT_XRC_TGT) {
-		atomic_inc(&pd->usecnt);
-		if (attr.send_cq)
-			atomic_inc(&attr.send_cq->usecnt);
-		if (attr.recv_cq)
-			atomic_inc(&attr.recv_cq->usecnt);
-		if (attr.srq)
-			atomic_inc(&attr.srq->usecnt);
-		if (ind_tbl)
-			atomic_inc(&ind_tbl->usecnt);
-	} else {
 		/* It is done in _ib_create_qp for other QP types */
 		qp->uobject = obj;
 	}

drivers/infiniband/core/uverbs_std_types_qp.c

@@ -258,18 +258,9 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QP_CREATE)(
 		ret = PTR_ERR(qp);
 		goto err_put;
 	}
+	ib_qp_usecnt_inc(qp);
 
-	if (attr.qp_type != IB_QPT_XRC_TGT) {
+	if (attr.qp_type == IB_QPT_XRC_TGT) {
-		atomic_inc(&pd->usecnt);
-		if (attr.send_cq)
-			atomic_inc(&attr.send_cq->usecnt);
-		if (attr.recv_cq)
-			atomic_inc(&attr.recv_cq->usecnt);
-		if (attr.srq)
-			atomic_inc(&attr.srq->usecnt);
-		if (attr.rwq_ind_tbl)
-			atomic_inc(&attr.rwq_ind_tbl->usecnt);
-	} else {
 		obj->uxrcd = container_of(xrcd_uobj, struct ib_uxrcd_object,
 					  uobject);
 		atomic_inc(&obj->uxrcd->refcnt);

drivers/infiniband/core/verbs.c

@@ -1274,6 +1274,36 @@ err_create:
 }
 EXPORT_SYMBOL(_ib_create_qp);
 
+void ib_qp_usecnt_inc(struct ib_qp *qp)
+{
+	if (qp->pd)
+		atomic_inc(&qp->pd->usecnt);
+	if (qp->send_cq)
+		atomic_inc(&qp->send_cq->usecnt);
+	if (qp->recv_cq)
+		atomic_inc(&qp->recv_cq->usecnt);
+	if (qp->srq)
+		atomic_inc(&qp->srq->usecnt);
+	if (qp->rwq_ind_tbl)
+		atomic_inc(&qp->rwq_ind_tbl->usecnt);
+}
+EXPORT_SYMBOL(ib_qp_usecnt_inc);
+
+void ib_qp_usecnt_dec(struct ib_qp *qp)
+{
+	if (qp->rwq_ind_tbl)
+		atomic_dec(&qp->rwq_ind_tbl->usecnt);
+	if (qp->srq)
+		atomic_dec(&qp->srq->usecnt);
+	if (qp->recv_cq)
+		atomic_dec(&qp->recv_cq->usecnt);
+	if (qp->send_cq)
+		atomic_dec(&qp->send_cq->usecnt);
+	if (qp->pd)
+		atomic_dec(&qp->pd->usecnt);
+}
+EXPORT_SYMBOL(ib_qp_usecnt_dec);
+
 struct ib_qp *ib_create_qp_kernel(struct ib_pd *pd,
 				  struct ib_qp_init_attr *qp_init_attr,
 				  const char *caller)
@@ -1306,14 +1336,7 @@ struct ib_qp *ib_create_qp_kernel(struct ib_pd *pd,
 		return xrc_qp;
 	}
 
-	if (qp_init_attr->recv_cq)
+	ib_qp_usecnt_inc(qp);
-		atomic_inc(&qp_init_attr->recv_cq->usecnt);
-	if (qp->srq)
-		atomic_inc(&qp_init_attr->srq->usecnt);
-
-	atomic_inc(&pd->usecnt);
-	if (qp_init_attr->send_cq)
-		atomic_inc(&qp_init_attr->send_cq->usecnt);
 
 	if (qp_init_attr->cap.max_rdma_ctxs) {
 		ret = rdma_rw_init_mrs(qp, qp_init_attr);
@@ -1971,10 +1994,6 @@ int ib_destroy_qp_user(struct ib_qp *qp, struct ib_udata *udata)
 {
 	const struct ib_gid_attr *alt_path_sgid_attr = qp->alt_path_sgid_attr;
 	const struct ib_gid_attr *av_sgid_attr = qp->av_sgid_attr;
-	struct ib_pd *pd;
-	struct ib_cq *scq, *rcq;
-	struct ib_srq *srq;
-	struct ib_rwq_ind_table *ind_tbl;
 	struct ib_qp_security *sec;
 	int ret;
 
@@ -1986,11 +2005,6 @@ int ib_destroy_qp_user(struct ib_qp *qp, struct ib_udata *udata)
 	if (qp->real_qp != qp)
 		return __ib_destroy_shared_qp(qp);
 
-	pd   = qp->pd;
-	scq  = qp->send_cq;
-	rcq  = qp->recv_cq;
-	srq  = qp->srq;
-	ind_tbl = qp->rwq_ind_tbl;
 	sec  = qp->qp_sec;
 	if (sec)
 		ib_destroy_qp_security_begin(sec);
@@ -2010,16 +2024,8 @@ int ib_destroy_qp_user(struct ib_qp *qp, struct ib_udata *udata)
 		rdma_put_gid_attr(alt_path_sgid_attr);
 	if (av_sgid_attr)
 		rdma_put_gid_attr(av_sgid_attr);
-	if (pd)
+
-		atomic_dec(&pd->usecnt);
+	ib_qp_usecnt_dec(qp);
-	if (scq)
-		atomic_dec(&scq->usecnt);
-	if (rcq)
-		atomic_dec(&rcq->usecnt);
-	if (srq)
-		atomic_dec(&srq->usecnt);
-	if (ind_tbl)
-		atomic_dec(&ind_tbl->usecnt);
 	if (sec)
 		ib_destroy_qp_security_end(sec);