target: Fix LUN_RESET active TMR descriptor handling
This patch fixes a NULL pointer se_cmd->cmd_kref < 0
refcount bug during TMR LUN_RESET with active TMRs,
triggered during se_cmd + se_tmr_req descriptor
shutdown + release via core_tmr_drain_tmr_list().
To address this bug, go ahead and obtain a local
kref_get_unless_zero(&se_cmd->cmd_kref) for active I/O
to set CMD_T_ABORTED, and transport_wait_for_tasks()
followed by the final target_put_sess_cmd() to drop
the local ->cmd_kref.
Also add two new checks within target_tmr_work() to
avoid CMD_T_ABORTED -> TFO->queue_tm_rsp() callbacks
ahead of invoking the backend -> fabric put in
transport_cmd_check_stop_to_fabric().
For good measure, also change core_tmr_release_req()
to use list_del_init() ahead of se_tmr_req memory
free.
Reviewed-by: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index af52f8b..94e372a 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2900,8 +2900,17 @@
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
struct se_device *dev = cmd->se_dev;
struct se_tmr_req *tmr = cmd->se_tmr_req;
+ unsigned long flags;
int ret;
+ spin_lock_irqsave(&cmd->t_state_lock, flags);
+ if (cmd->transport_state & CMD_T_ABORTED) {
+ tmr->response = TMR_FUNCTION_REJECTED;
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+ goto check_stop;
+ }
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
switch (tmr->function) {
case TMR_ABORT_TASK:
core_tmr_abort_task(dev, tmr, cmd->se_sess);
@@ -2934,9 +2943,17 @@
break;
}
+ spin_lock_irqsave(&cmd->t_state_lock, flags);
+ if (cmd->transport_state & CMD_T_ABORTED) {
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+ goto check_stop;
+ }
cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
cmd->se_tfo->queue_tm_rsp(cmd);
+check_stop:
transport_cmd_check_stop_to_fabric(cmd);
}