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Commit 04629b7b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Nicholas Bellinger
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target: Remove unnecessary se_task members 



This is a squashed version of the following unnecessary se_task structure
member removal patches:

target: remove the task_execute_queue field in se_task

    Instead of using a separate flag we can simply do list_emptry checks
    on t_execute_list if we make sure to always use list_del_init to remove
    a task from the list.  Also factor some duplicate code into a new
    __transport_remove_task_from_execute_queue helper.

target: remove the read-only task_no field in se_task

    The task_no field never was initialized and only used in debug printks,
    so kill it.

target: remove the task_padded_sg field in se_task

    This field is only check in one place and not actually needed there.

    Rationale:
    - transport_do_task_sg_chain asserts that we have task_sg_chaining
      set early on
    - we only make use of the sg_prev_nents field we calculate based on it
      if there is another sg list that gets chained onto this one, which
      never happens for the last (or only) task.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 6c76bf95

drivers/target/target_core_tmr.c

+2 −5
Original line number Diff line number Diff line
@@ -226,11 +226,8 @@ static void core_tmr_drain_task_list( 
		/*

		 * Remove from task execute list before processing drain_task_list

		 */

		if (atomic_read(&task->task_execute_queue) != 0) {

			list_del(&task->t_execute_list);

			atomic_set(&task->task_execute_queue, 0);

			atomic_dec(&dev->execute_tasks);

		}

		if (!list_empty(&task->t_execute_list))

			__transport_remove_task_from_execute_queue(task, dev);

	}

	spin_unlock_irqrestore(&dev->execute_task_lock, flags);

drivers/target/target_core_transport.c

+24 −35
Original line number Diff line number Diff line
@@ -915,38 +915,36 @@ static void transport_add_tasks_from_cmd(struct se_cmd *cmd) 


	spin_lock_irqsave(&dev->execute_task_lock, flags);

	list_for_each_entry(task, &cmd->t_task_list, t_list) {

		if (atomic_read(&task->task_execute_queue))

		if (!list_empty(&task->t_execute_list))

			continue;

		/*

		 * __transport_add_task_to_execute_queue() handles the

		 * SAM Task Attribute emulation if enabled

		 */

		__transport_add_task_to_execute_queue(task, task_prev, dev);

		atomic_set(&task->task_execute_queue, 1);

		task_prev = task;

	}

	spin_unlock_irqrestore(&dev->execute_task_lock, flags);

}



/*	transport_remove_task_from_execute_queue():

 *

 *

 */

void __transport_remove_task_from_execute_queue(struct se_task *task,

		struct se_device *dev)

{

	list_del_init(&task->t_execute_list);

	atomic_dec(&dev->execute_tasks);

}



void transport_remove_task_from_execute_queue(

	struct se_task *task,

	struct se_device *dev)

{

	unsigned long flags;



	if (atomic_read(&task->task_execute_queue) == 0) {

		dump_stack();

	if (WARN_ON(list_empty(&task->t_execute_list)))

		return;

	}



	spin_lock_irqsave(&dev->execute_task_lock, flags);

	list_del(&task->t_execute_list);

	atomic_set(&task->task_execute_queue, 0);

	atomic_dec(&dev->execute_tasks);

	__transport_remove_task_from_execute_queue(task, dev);

	spin_unlock_irqrestore(&dev->execute_task_lock, flags);

}
@@ -1787,8 +1785,7 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd) 
	spin_lock_irqsave(&cmd->t_state_lock, flags);

	list_for_each_entry_safe(task, task_tmp,

				&cmd->t_task_list, t_list) {

		pr_debug("task_no[%d] - Processing task %p\n",

				task->task_no, task);

		pr_debug("Processing task %p\n", task);

		/*

		 * If the struct se_task has not been sent and is not active,

		 * remove the struct se_task from the execution queue.
@@ -1799,8 +1796,7 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd) 
			transport_remove_task_from_execute_queue(task,

					cmd->se_dev);



			pr_debug("task_no[%d] - Removed from execute queue\n",

				task->task_no);

			pr_debug("Task %p removed from execute queue\n", task);

			spin_lock_irqsave(&cmd->t_state_lock, flags);

			continue;

		}
@@ -1814,17 +1810,15 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd) 
			spin_unlock_irqrestore(&cmd->t_state_lock,

					flags);



			pr_debug("task_no[%d] - Waiting to complete\n",

				task->task_no);

			pr_debug("Task %p waiting to complete\n", task);

			wait_for_completion(&task->task_stop_comp);

			pr_debug("task_no[%d] - Stopped successfully\n",

				task->task_no);

			pr_debug("Task %p stopped successfully\n", task);



			spin_lock_irqsave(&cmd->t_state_lock, flags);

			atomic_dec(&cmd->t_task_cdbs_left);

			task->task_flags &= ~(TF_ACTIVE | TF_REQUEST_STOP);

		} else {

			pr_debug("task_no[%d] - Did nothing\n", task->task_no);

			pr_debug("Task %p - did nothing\n", task);

			ret++;

		}
@@ -2347,9 +2341,7 @@ check_depth: 
	}

	task = list_first_entry(&dev->execute_task_list,

				struct se_task, t_execute_list);

	list_del(&task->t_execute_list);

	atomic_set(&task->task_execute_queue, 0);

	atomic_dec(&dev->execute_tasks);

	__transport_remove_task_from_execute_queue(task, dev);

	spin_unlock_irq(&dev->execute_task_lock);



	atomic_dec(&dev->depth_left);
@@ -2681,9 +2673,9 @@ static int transport_get_sense_data(struct se_cmd *cmd) 


		sense_buffer = dev->transport->get_sense_buffer(task);

		if (!sense_buffer) {

			pr_err("ITT[0x%08x]_TASK[%d]: Unable to locate"

			pr_err("ITT[0x%08x]_TASK[%p]: Unable to locate"

				" sense buffer for task with sense\n",

				cmd->se_tfo->get_task_tag(cmd), task->task_no);

				cmd->se_tfo->get_task_tag(cmd), task);

			continue;

		}

		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
@@ -3897,15 +3889,13 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) 
		/*

		 * For the padded tasks, use the extra SGL vector allocated

		 * in transport_allocate_data_tasks() for the sg_prev_nents

		 * offset into sg_chain() above..  The last task of a

		 * multi-task list, or a single task will not have

		 * task->task_sg_padded set..

		 * offset into sg_chain() above.

		 *

		 * We do not need the padding for the last task (or a single

		 * task), but in that case we will never use the sg_prev_nents

		 * value below which would be incorrect.

		 */

		if (task->task_padded_sg)

		sg_prev_nents = (task->task_sg_nents + 1);

		else

			sg_prev_nents = task->task_sg_nents;



		sg_prev = task->task_sg;

	}

	/*
@@ -3992,7 +3982,6 @@ static int transport_allocate_data_tasks( 
		 */

		if (cmd->se_tfo->task_sg_chaining && (i < (task_count - 1))) {

			task_sg_nents_padded = (task->task_sg_nents + 1);

			task->task_padded_sg = 1;

		} else

			task_sg_nents_padded = task->task_sg_nents;

include/target/target_core_base.h

+0 −3
Original line number Diff line number Diff line
@@ -409,15 +409,12 @@ struct se_task { 
	u8		task_scsi_status;

	u8		task_flags;

	int		task_error_status;

	bool		task_padded_sg;

	unsigned long long	task_lba;

	u32		task_no;

	u32		task_sectors;

	u32		task_size;

	enum dma_data_direction	task_data_direction;

	struct se_cmd *task_se_cmd;

	struct completion	task_stop_comp;

	atomic_t	task_execute_queue;

	atomic_t	task_state_active;

	struct timer_list	task_timer;

	struct list_head t_list;

include/target/target_core_transport.h

+2 −0
Original line number Diff line number Diff line
@@ -135,6 +135,8 @@ extern void transport_add_task_to_execute_queue(struct se_task *, 
						struct se_device *);

extern void transport_remove_task_from_execute_queue(struct se_task *,

						struct se_device *);

extern void __transport_remove_task_from_execute_queue(struct se_task *,

						struct se_device *);

unsigned char *transport_dump_cmd_direction(struct se_cmd *);

extern void transport_dump_dev_state(struct se_device *, char *, int *);

extern void transport_dump_dev_info(struct se_device *, struct se_lun *,