[CONNECTOR]: async connector mode.

If input message rate from userspace is too high, do not drop them,
but try to deliver using work queue allocation.

Failing there is some kind of congestion control.

It also removes warn_on on this condition, which scares people.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 36 deletions

diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index aaf6d46..bb0b3a8 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -84,7 +84,7 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, int gfp_mask)
 		spin_lock_bh(&dev->cbdev->queue_lock);
 		list_for_each_entry(__cbq, &dev->cbdev->queue_list,
 				    callback_entry) {
-			if (cn_cb_equal(&__cbq->cb->id, &msg->id)) {
+			if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
 				found = 1;
 				group = __cbq->group;
 			}
@@ -127,42 +127,56 @@ static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), v
 {
 	struct cn_callback_entry *__cbq;
 	struct cn_dev *dev = &cdev;
-	int found = 0;
+	int err = -ENODEV;
 
 	spin_lock_bh(&dev->cbdev->queue_lock);
 	list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) {
-		if (cn_cb_equal(&__cbq->cb->id, &msg->id)) {
-			/*
-			 * Let's scream if there is some magic and the
-			 * data will arrive asynchronously here.
-			 * [i.e. netlink messages will be queued].
-			 * After the first warning I will fix it
-			 * quickly, but now I think it is
-			 * impossible. --zbr (2004_04_27).
-			 */
+		if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
 			if (likely(!test_bit(0, &__cbq->work.pending) &&
-					__cbq->ddata == NULL)) {
-				__cbq->cb->priv = msg;
+					__cbq->data.ddata == NULL)) {
+				__cbq->data.callback_priv = msg;
 
-				__cbq->ddata = data;
-				__cbq->destruct_data = destruct_data;
+				__cbq->data.ddata = data;
+				__cbq->data.destruct_data = destruct_data;
 
 				if (queue_work(dev->cbdev->cn_queue,
 						&__cbq->work))
-					found = 1;
+					err = 0;
 			} else {
-				printk("%s: cbq->data=%p, "
-				       "work->pending=%08lx.\n",
-				       __func__, __cbq->ddata,
-				       __cbq->work.pending);
-				WARN_ON(1);
+				struct work_struct *w;
+				struct cn_callback_data *d;
+				
+				w = kzalloc(sizeof(*w) + sizeof(*d), GFP_ATOMIC);
+				if (w) {
+					d = (struct cn_callback_data *)(w+1);
+
+					d->callback_priv = msg;
+					d->callback = __cbq->data.callback;
+					d->ddata = data;
+					d->destruct_data = destruct_data;
+					d->free = w;
+
+					INIT_LIST_HEAD(&w->entry);
+					w->pending = 0;
+					w->func = &cn_queue_wrapper;
+					w->data = d;
+					init_timer(&w->timer);
+					
+					if (queue_work(dev->cbdev->cn_queue, w))
+						err = 0;
+					else {
+						kfree(w);
+						err = -EINVAL;
+					}
+				} else
+					err = -ENOMEM;
 			}
 			break;
 		}
 	}
 	spin_unlock_bh(&dev->cbdev->queue_lock);
 
-	return found ? 0 : -ENODEV;
+	return err;
 }
 
 /*
@@ -291,22 +305,10 @@ int cn_add_callback(struct cb_id *id, char *name, void (*callback)(void *))
 {
 	int err;
 	struct cn_dev *dev = &cdev;
-	struct cn_callback *cb;
-
-	cb = kzalloc(sizeof(*cb), GFP_KERNEL);
-	if (!cb)
-		return -ENOMEM;
-
-	scnprintf(cb->name, sizeof(cb->name), "%s", name);
 
-	memcpy(&cb->id, id, sizeof(cb->id));
-	cb->callback = callback;
-
-	err = cn_queue_add_callback(dev->cbdev, cb);
-	if (err) {
-		kfree(cb);
+	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
+	if (err)
 		return err;
-	}
 
 	cn_notify(id, 0);