From 879e5bd5a1a0a317fb67fa4dc550db092a7bdcb0 Mon Sep 17 00:00:00 2001 From: Faisal Latif Date: Fri, 21 Nov 2008 20:50:41 -0600 Subject: [PATCH] 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: Faisal Latif Signed-off-by: Chien Tung Signed-off-by: Roland Dreier --- drivers/infiniband/hw/nes/nes_cm.c | 40 +++++++++++++++++++++--------- drivers/infiniband/hw/nes/nes_cm.h | 2 ++ 2 files changed, 30 insertions(+), 12 deletions(-) diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c index 2a1d6c7f8d32..257d994ec7b5 100644 --- a/drivers/infiniband/hw/nes/nes_cm.c +++ b/drivers/infiniband/hw/nes/nes_cm.c @@ -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_core->connected_nodes) { cm_node = container_of(list_node, struct nes_cm_node, list); - add_ref_cm_node(cm_node); - spin_unlock_irqrestore(&cm_core->ht_lock, flags); + 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)) { @@ -925,28 +933,36 @@ 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, - &g_cm_core->connected_nodes) { + &g_cm_core->connected_nodes) { cm_node = container_of(list_pos, struct nes_cm_node, 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); + (!cm_node->accelerated)) { + 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); diff --git a/drivers/infiniband/hw/nes/nes_cm.h b/drivers/infiniband/hw/nes/nes_cm.h index 367b3d290140..282a9cbe508f 100644 --- a/drivers/infiniband/hw/nes/nes_cm.h +++ b/drivers/infiniband/hw/nes/nes_cm.h @@ -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; }; -- 2.34.1