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Commit 879e5bd5 authored by Faisal Latif's avatar Faisal Latif Committed by Roland Dreier
Browse files

RDMA/nes: Lock down connected_nodes list while processing it 



While processing connected_nodes list, we would release the lock when
we need to send reset to remote partner.  That created a window where
the list can be modified.  Change this into a two step process: place
nodes that need processing on a local list then process the local list.

Signed-off-by: default avatarFaisal Latif <faisal.latif@intel.com>
Signed-off-by: default avatarChien Tung <chien.tin.tung@intel.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent c5d321e5

drivers/infiniband/hw/nes/nes_cm.c

+28 −12
Original line number Diff line number Diff line
@@ -459,13 +459,23 @@ static void nes_cm_timer_tick(unsigned long pass) 
	int ret = NETDEV_TX_OK;

	enum nes_cm_node_state last_state;



	struct list_head timer_list;

	INIT_LIST_HEAD(&timer_list);

	spin_lock_irqsave(&cm_core->ht_lock, flags);



	list_for_each_safe(list_node, list_core_temp,

				&cm_core->connected_nodes) {

		cm_node = container_of(list_node, struct nes_cm_node, list);

		if (!list_empty(&cm_node->recv_list) || (cm_node->send_entry)) {

			add_ref_cm_node(cm_node);

			list_add(&cm_node->timer_entry, &timer_list);

		}

	}

	spin_unlock_irqrestore(&cm_core->ht_lock, flags);



	list_for_each_safe(list_node, list_core_temp, &timer_list) {

		cm_node = container_of(list_node, struct nes_cm_node,

					timer_entry);

		spin_lock_irqsave(&cm_node->recv_list_lock, flags);

		list_for_each_safe(list_core, list_node_temp,

			&cm_node->recv_list) {
@@ -615,14 +625,12 @@ static void nes_cm_timer_tick(unsigned long pass) 


		spin_unlock_irqrestore(&cm_node->retrans_list_lock, flags);

		rem_ref_cm_node(cm_node->cm_core, cm_node);

		spin_lock_irqsave(&cm_core->ht_lock, flags);

		if (ret != NETDEV_TX_OK) {

			nes_debug(NES_DBG_CM, "rexmit failed for cm_node=%p\n",

				cm_node);

			break;

		}

	}

	spin_unlock_irqrestore(&cm_core->ht_lock, flags);



	if (settimer) {

		if (!timer_pending(&cm_core->tcp_timer)) {
@@ -925,11 +933,13 @@ static int mini_cm_dec_refcnt_listen(struct nes_cm_core *cm_core, 
	struct list_head *list_pos = NULL;

	struct list_head *list_temp = NULL;

	struct nes_cm_node *cm_node = NULL;

	struct list_head reset_list;



	nes_debug(NES_DBG_CM, "attempting listener= %p free_nodes= %d, "

		"refcnt=%d\n", listener, free_hanging_nodes,

		atomic_read(&listener->ref_count));

	/* free non-accelerated child nodes for this listener */

	INIT_LIST_HEAD(&reset_list);

	if (free_hanging_nodes) {

		spin_lock_irqsave(&cm_core->ht_lock, flags);

		list_for_each_safe(list_pos, list_temp,
@@ -938,15 +948,21 @@ static int mini_cm_dec_refcnt_listen(struct nes_cm_core *cm_core, 
				list);

			if ((cm_node->listener == listener) &&

			    (!cm_node->accelerated)) {

				cleanup_retrans_entry(cm_node);

				spin_unlock_irqrestore(&cm_core->ht_lock,

					flags);

				send_reset(cm_node, NULL);

				spin_lock_irqsave(&cm_core->ht_lock, flags);

				add_ref_cm_node(cm_node);

				list_add(&cm_node->reset_entry, &reset_list);

			}

		}

		spin_unlock_irqrestore(&cm_core->ht_lock, flags);

	}



	list_for_each_safe(list_pos, list_temp, &reset_list) {

		cm_node = container_of(list_pos, struct nes_cm_node,

					reset_entry);

		cleanup_retrans_entry(cm_node);

		send_reset(cm_node, NULL);

		rem_ref_cm_node(cm_node->cm_core, cm_node);

	}



	spin_lock_irqsave(&cm_core->listen_list_lock, flags);

	if (!atomic_dec_return(&listener->ref_count)) {

		list_del(&listener->list);

drivers/infiniband/hw/nes/nes_cm.h

+2 −0
Original line number Diff line number Diff line
@@ -292,6 +292,8 @@ struct nes_cm_node { 
	int                       apbvt_set;

	int                       accept_pend;

	int			freed;

	struct list_head	timer_entry;

	struct list_head	reset_entry;

	struct nes_qp		*nesqp;

};