target: Use complete_all for se_cmd->t_transport_stop_comp

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>

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 7dddabe831790bd3de9f129bb418239bd4131054..f2c5ed90d3569783f828b9665db0020ab948d6d8 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -488,7 +488,7 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
 
                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 *cmd, u8 scsi_status)
        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 *cmd)
                        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;
        }