IB/uverbs: track multicast group membership for userspace QPs

uverbs needs to track which multicast groups is each qp
attached to, in order to properly detach when cleanup
is performed on device file close.

Signed-off-by: Jack Morgenstein <[e-mail]>
Signed-off-by: Michael S. Tsirkin <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/core/uverbs.h

···
 	u32				       *counter;
 };
 
+struct ib_uverbs_mcast_entry {
+	struct list_head	list;
+	union ib_gid 		gid;
+	u16 			lid;
+};
+
 struct ib_uevent_object {
 	struct ib_uobject	uobject;
 	struct list_head	event_list;
 	u32			events_reported;
+};
+
+struct ib_uqp_object {
+	struct ib_uevent_object	uevent;
+	struct list_head 	mcast_list;
 };
 
 struct ib_ucq_object {

drivers/infiniband/core/uverbs_cmd.c

···
 	struct ib_uverbs_create_qp      cmd;
 	struct ib_uverbs_create_qp_resp resp;
 	struct ib_udata                 udata;
-	struct ib_uevent_object        *uobj;
+	struct ib_uqp_object           *uobj;
 	struct ib_pd                   *pd;
 	struct ib_cq                   *scq, *rcq;
 	struct ib_srq                  *srq;
···
 	attr.cap.max_recv_sge    = cmd.max_recv_sge;
 	attr.cap.max_inline_data = cmd.max_inline_data;
 
-	uobj->uobject.user_handle = cmd.user_handle;
-	uobj->uobject.context     = file->ucontext;
-	uobj->events_reported     = 0;
-	INIT_LIST_HEAD(&uobj->event_list);
+	uobj->uevent.uobject.user_handle = cmd.user_handle;
+	uobj->uevent.uobject.context     = file->ucontext;
+	uobj->uevent.events_reported     = 0;
+	INIT_LIST_HEAD(&uobj->uevent.event_list);
+	INIT_LIST_HEAD(&uobj->mcast_list);
 
 	qp = pd->device->create_qp(pd, &attr, &udata);
 	if (IS_ERR(qp)) {
···
 	qp->send_cq    	  = attr.send_cq;
 	qp->recv_cq    	  = attr.recv_cq;
 	qp->srq	       	  = attr.srq;
-	qp->uobject       = &uobj->uobject;
+	qp->uobject       = &uobj->uevent.uobject;
 	qp->event_handler = attr.event_handler;
 	qp->qp_context    = attr.qp_context;
 	qp->qp_type	  = attr.qp_type;
···
 		goto err_destroy;
 	}
 
-	ret = idr_get_new(&ib_uverbs_qp_idr, qp, &uobj->uobject.id);
+	ret = idr_get_new(&ib_uverbs_qp_idr, qp, &uobj->uevent.uobject.id);
 
 	if (ret == -EAGAIN)
 		goto retry;
 	if (ret)
 		goto err_destroy;
 
-	resp.qp_handle       = uobj->uobject.id;
+	resp.qp_handle       = uobj->uevent.uobject.id;
 	resp.max_recv_sge    = attr.cap.max_recv_sge;
 	resp.max_send_sge    = attr.cap.max_send_sge;
 	resp.max_recv_wr     = attr.cap.max_recv_wr;
···
 	}
 
 	down(&file->mutex);
-	list_add_tail(&uobj->uobject.list, &file->ucontext->qp_list);
+	list_add_tail(&uobj->uevent.uobject.list, &file->ucontext->qp_list);
 	up(&file->mutex);
 
 	up(&ib_uverbs_idr_mutex);
···
 	return in_len;
 
 err_idr:
-	idr_remove(&ib_uverbs_qp_idr, uobj->uobject.id);
+	idr_remove(&ib_uverbs_qp_idr, uobj->uevent.uobject.id);
 
 err_destroy:
 	ib_destroy_qp(qp);
···
 	struct ib_uverbs_destroy_qp      cmd;
 	struct ib_uverbs_destroy_qp_resp resp;
 	struct ib_qp               	*qp;
-	struct ib_uevent_object        	*uobj;
+	struct ib_uqp_object        	*uobj;
 	int                        	 ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
···
 	if (!qp || qp->uobject->context != file->ucontext)
 		goto out;
 
-	uobj = container_of(qp->uobject, struct ib_uevent_object, uobject);
+	uobj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
+
+	if (!list_empty(&uobj->mcast_list)) {
+		ret = -EBUSY;
+		goto out;
+	}
 
 	ret = ib_destroy_qp(qp);
 	if (ret)
···
 	idr_remove(&ib_uverbs_qp_idr, cmd.qp_handle);
 
 	down(&file->mutex);
-	list_del(&uobj->uobject.list);
+	list_del(&uobj->uevent.uobject.list);
 	up(&file->mutex);
 
-	ib_uverbs_release_uevent(file, uobj);
+	ib_uverbs_release_uevent(file, &uobj->uevent);
 
-	resp.events_reported = uobj->events_reported;
+	resp.events_reported = uobj->uevent.events_reported;
 
 	kfree(uobj);
 
···
 {
 	struct ib_uverbs_attach_mcast cmd;
 	struct ib_qp                 *qp;
+	struct ib_uqp_object         *uobj;
+	struct ib_uverbs_mcast_entry *mcast;
 	int                           ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
···
 	down(&ib_uverbs_idr_mutex);
 
 	qp = idr_find(&ib_uverbs_qp_idr, cmd.qp_handle);
-	if (qp && qp->uobject->context == file->ucontext)
-		ret = ib_attach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
+	if (!qp || qp->uobject->context != file->ucontext)
+		goto out;
 
+	uobj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
+
+	list_for_each_entry(mcast, &uobj->mcast_list, list)
+		if (cmd.mlid == mcast->lid &&
+		    !memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
+			ret = 0;
+			goto out;
+		}
+
+	mcast = kmalloc(sizeof *mcast, GFP_KERNEL);
+	if (!mcast) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mcast->lid = cmd.mlid;
+	memcpy(mcast->gid.raw, cmd.gid, sizeof mcast->gid.raw);
+
+	ret = ib_attach_mcast(qp, &mcast->gid, cmd.mlid);
+	if (!ret) {
+		uobj = container_of(qp->uobject, struct ib_uqp_object,
+				    uevent.uobject);
+		list_add_tail(&mcast->list, &uobj->mcast_list);
+	} else
+		kfree(mcast);
+
+out:
 	up(&ib_uverbs_idr_mutex);
 
 	return ret ? ret : in_len;
···
 			       int out_len)
 {
 	struct ib_uverbs_detach_mcast cmd;
+	struct ib_uqp_object         *uobj;
 	struct ib_qp                 *qp;
+	struct ib_uverbs_mcast_entry *mcast;
 	int                           ret = -EINVAL;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
···
 	down(&ib_uverbs_idr_mutex);
 
 	qp = idr_find(&ib_uverbs_qp_idr, cmd.qp_handle);
-	if (qp && qp->uobject->context == file->ucontext)
-		ret = ib_detach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
+	if (!qp || qp->uobject->context != file->ucontext)
+		goto out;
 
+	ret = ib_detach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
+	if (ret)
+		goto out;
+
+	uobj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
+
+	list_for_each_entry(mcast, &uobj->mcast_list, list)
+		if (cmd.mlid == mcast->lid &&
+		    !memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
+			list_del(&mcast->list);
+			kfree(mcast);
+			break;
+		}
+
+out:
 	up(&ib_uverbs_idr_mutex);
 
 	return ret ? ret : in_len;

drivers/infiniband/core/uverbs_main.c

···
 	spin_unlock_irq(&file->async_file->lock);
 }
 
+static void ib_uverbs_detach_umcast(struct ib_qp *qp,
+				    struct ib_uqp_object *uobj)
+{
+	struct ib_uverbs_mcast_entry *mcast, *tmp;
+
+	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
+		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
+		list_del(&mcast->list);
+		kfree(mcast);
+	}
+}
+
 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
 				      struct ib_ucontext *context)
 {
···
 
 	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
 		struct ib_qp *qp = idr_find(&ib_uverbs_qp_idr, uobj->id);
-		struct ib_uevent_object *uevent =
-			container_of(uobj, struct ib_uevent_object, uobject);
+		struct ib_uqp_object *uqp =
+			container_of(uobj, struct ib_uqp_object, uevent.uobject);
 		idr_remove(&ib_uverbs_qp_idr, uobj->id);
+		ib_uverbs_detach_umcast(qp, uqp);
 		ib_destroy_qp(qp);
 		list_del(&uobj->list);
-		ib_uverbs_release_uevent(file, uevent);
-		kfree(uevent);
+		ib_uverbs_release_uevent(file, &uqp->uevent);
+		kfree(uqp);
 	}
 
 	list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {