Re: [PATCH 13/13] target: flush submission work during TMR processing

On 2/9/21 11:05 AM, Bodo Stroesser wrote:

On 09.02.21 13:38, Mike Christie wrote:

quoted

If a cmd is on the submission workqueue then the TMR code will
miss it, and end up returning task not found or success for
lun resets. The fabric driver might then tell the initiator that
the running cmds have been handled when they are about to run.

This adds a cancel when we are processing TMRs.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
  drivers/target/target_core_tmr.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 7347285471fa..9b7f159f9341 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c

@@ -124,6 +124,8 @@ void core_tmr_abort_task(
  	int i;
  
  	for (i = 0; i < dev->queue_cnt; i++) {
+		cancel_work_sync(&dev->queues[i].sq.work);
+
  		spin_lock_irqsave(&dev->queues[i].lock, flags);
  		list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list,
  					 state_list) {

@@ -302,6 +304,8 @@ static void core_tmr_drain_state_list(
  	 * in the Control Mode Page.
  	 */
  	for (i = 0; i < dev->queue_cnt; i++) {
+		cancel_work_sync(&dev->queues[i].sq.work);
+
  		spin_lock_irqsave(&dev->queues[i].lock, flags);
  		list_for_each_entry_safe(cmd, next, &dev->queues[i].state_list,
  					 state_list) {

Is there a possible race?

I mean, if cancel_work_sync() is called for a work that was queued but not started,
can we end up with cmds sleeping in a queue until a further cmd is queued to the same queue?

Oh yeah, you are right cancel is wrong. It should be a flush.