[PATCH 3.10 53/77] target: Use complete_all for se_cmd->t_transport_stop_comp

Greg Kroah-Hartman
2014-06-28T19:04:30Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

commit a95d6511303b848da45ee27b35018bb58087bdc6 upstream.

This patch fixes a bug where multiple waiters on ->t_transport_stop_comp
occurs due to a concurrent ABORT_TASK and session reset both invoking
transport_wait_for_tasks(), while waiting for the associated se_cmd
descriptor backend processing to complete.

For this case, complete_all() should be invoked in order to wake up
both waiters in core_tmr_abort_task() + transport_generic_free_cmd()
process contexts.

Cc: Thomas Glanzmann <thomas@glanzmann.de>
Cc: Charalampos Pournaris <charpour@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/target/target_core_transport.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -488,7 +488,7 @@ static int transport_cmd_check_stop(stru

spin_unlock_irqrestore(&cmd->t_state_lock, flags);

- complete(&cmd->t_transport_stop_comp);
+ complete_all(&cmd->t_transport_stop_comp);
return 1;
}

@@ -617,7 +617,7 @@ void target_complete_cmd(struct se_cmd *
if (cmd->transport_state & CMD_T_ABORTED &&
cmd->transport_state & CMD_T_STOP) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- complete(&cmd->t_transport_stop_comp);
+ complete_all(&cmd->t_transport_stop_comp);
return;
} else if (cmd->transport_state & CMD_T_FAILED) {
INIT_WORK(&cmd->work, target_complete_failure_work);
@@ -1688,7 +1688,7 @@ void target_execute_cmd(struct se_cmd *c
cmd->se_tfo->get_task_tag(cmd));

spin_unlock_irq(&cmd->t_state_lock);
- complete(&cmd->t_transport_stop_comp);
+ complete_all(&cmd->t_transport_stop_comp);
return;
}