[PATCH 4/6] target: Fix task->task_execute_queue=1 clear bug + LUN_RESET OOPs

From: Nicholas A. Bellinger
Date: Thu May 19 2011 - 23:20:21 EST


From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch fixes a bug where task->task_execute_queue=1 was not being
cleared once se_task had been removed from se_device->execute_task_list,
resulting in an OOPs in core_tmr_lun_reset() for the task->task_active=0
case where transport_remove_task_from_execute_queue() was incorrectly
being called.

This patch fixes two cases in transport_get_task_from_execute_queue()
and transport_remove_task_from_execute_queue() to properly clear
task->task_execute_queue=0 once list_del(&task->t_execute_list) has
been called.

It also adds an explict check in transport_remove_task_from_execute_queue()
to dump_stack + return if called with task->task_execute_queue=0.

Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 3eeb3e2..beaf8fa 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1194,6 +1194,7 @@ transport_get_task_from_execute_queue(struct se_device *dev)
break;

list_del(&task->t_execute_list);
+ atomic_set(&task->task_execute_queue, 0);
atomic_dec(&dev->execute_tasks);

return task;
@@ -1209,8 +1210,14 @@ void transport_remove_task_from_execute_queue(
{
unsigned long flags;

+ if (atomic_read(&task->task_execute_queue) == 0) {
+ dump_stack();
+ return;
+ }
+
spin_lock_irqsave(&dev->execute_task_lock, flags);
list_del(&task->t_execute_list);
+ atomic_set(&task->task_execute_queue, 0);
atomic_dec(&dev->execute_tasks);
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
--
1.7.5.1

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