scsi: qla2xxx: Add qla2x00_async_done() for async routines

This done routine will delete the timer and check for its return value and
decrease the reference count accordingly. This prevents boot hangs reported
after commit 31e6cdbe0e ("scsi: qla2xxx: Implement ref count for SRB")
was merged.

Link: https://lore.kernel.org/r/20220208093946.4471-1-njavali@marvell.com
Fixes: 31e6cdbe0e ("scsi: qla2xxx: Implement ref count for SRB")
Reported-by: Ewan Milne <emilne@redhat.com>
Tested-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_iocb.c

@@ -2560,6 +2560,20 @@ qla24xx_tm_iocb(srb_t *sp, struct tsk_mgmt_entry *tsk)
 	}
 }
 
+static void
+qla2x00_async_done(struct srb *sp, int res)
+{
+	if (del_timer(&sp->u.iocb_cmd.timer)) {
+		/*
+		 * Successfully cancelled the timeout handler
+		 * ref: TMR
+		 */
+		if (kref_put(&sp->cmd_kref, qla2x00_sp_release))
+			return;
+	}
+	sp->async_done(sp, res);
+}
+
 void
 qla2x00_sp_release(struct kref *kref)
 {
@@ -2573,7 +2587,8 @@ qla2x00_init_async_sp(srb_t *sp, unsigned long tmo,
 		     void (*done)(struct srb *sp, int res))
 {
 	timer_setup(&sp->u.iocb_cmd.timer, qla2x00_sp_timeout, 0);
-	sp->done = done;
+	sp->done = qla2x00_async_done;
+	sp->async_done = done;
 	sp->free = qla2x00_sp_free;
 	sp->u.iocb_cmd.timeout = qla2x00_async_iocb_timeout;
 	sp->u.iocb_cmd.timer.expires = jiffies + tmo * HZ;