target: simplify command to task linkage

Now that we only have a single task per command we can use a direct pointer
to it instead of list.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_tmr.c

@@ -321,13 +321,11 @@ static void core_tmr_drain_task_list(
 			cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 			cmd->t_task_cdb[0]);
 		pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
-			" t_task_cdbs: %d t_task_cdbs_left: %d"
-			" t_task_cdbs_sent: %d -- CMD_T_ACTIVE: %d"
+			" t_task_cdbs_left: %d"
+			" -- CMD_T_ACTIVE: %d"
 			" CMD_T_STOP: %d CMD_T_SENT: %d\n",
 			cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
-			cmd->t_task_list_num,
 			atomic_read(&cmd->t_task_cdbs_left),
-			atomic_read(&cmd->t_task_cdbs_sent),
 			(cmd->transport_state & CMD_T_ACTIVE) != 0,
 			(cmd->transport_state & CMD_T_STOP) != 0,
 			(cmd->transport_state & CMD_T_SENT) != 0);

include/target/target_core_base.h

@@ -492,7 +492,6 @@ struct se_task {
 	u16			task_flags;
 	u8			task_scsi_status;
 	enum dma_data_direction	task_data_direction;
-	struct list_head	t_list;
 	struct list_head	t_execute_list;
 	struct list_head	t_state_list;
 	bool			t_state_active;
@@ -573,7 +572,6 @@ struct se_cmd {
 	atomic_t		t_se_count;
 	atomic_t		t_task_cdbs_left;
 	atomic_t		t_task_cdbs_ex_left;
-	atomic_t		t_task_cdbs_sent;
 	unsigned int		transport_state;
 #define CMD_T_ABORTED		(1 << 0)
 #define CMD_T_ACTIVE		(1 << 1)
@@ -598,10 +596,7 @@ struct se_cmd {
 	struct scatterlist	*t_bidi_data_sg;
 	unsigned int		t_bidi_data_nents;
 
-	/* Used for BIDI READ */
-	struct list_head	t_task_list;
-	u32			t_task_list_num;
-
+	struct se_task		*t_task;
 };
 
 struct se_ua {