4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit 9574a497df2bbc0a676b609ce0dd24d237cee3a6 upstream.
This patch fixes a potential end-less loop during QUEUE_FULL,
where cmd->se_tfo->write_pending() callback fails repeatedly
but __transport_wait_for_tasks() has already been invoked to
quiese the outstanding se_cmd descriptor.
To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED
check within transport_write_pending_qf() and invokes the
existing se_cmd->t_transport_stop_comp to signal quiese
completion back to __transport_wait_for_tasks().
Cc: Mike Christie <mchristi@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Bryant G. Ly <bryantly@xxxxxxxxxxxxxxxxxx>
Cc: Michael Cyr <mikecyr@xxxxxxxxxxxxxxxxxx>
Cc: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2575,7 +2575,20 @@ EXPORT_SYMBOL(transport_generic_new_cmd)
static void transport_write_pending_qf(struct se_cmd *cmd)
{
+ unsigned long flags;
int ret;
+ bool stop;
+
+ spin_lock_irqsave(&cmd->t_state_lock, flags);
+ stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+ if (stop) {
+ pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
+ __func__, __LINE__, cmd->tag);
+ complete_all(&cmd->t_transport_stop_comp);
+ return;
+ }
ret = cmd->se_tfo->write_pending(cmd);
if (ret) {