Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit da0f7619 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Nicholas Bellinger
Browse files

target: merge transport_new_cmd_obj into transport_generic_new_cmd 



These are two fairly small functions, and merging them gives a much
more readable control flow, and opportunities for more useful comments.

It also moves all code related to resources allocation closer together
and allows to remove a forward declaration for transport_allocate_tasks.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 7c1c6af3

drivers/target/target_core_transport.c

+53 −76
Original line number Diff line number Diff line
@@ -77,10 +77,6 @@ static void transport_handle_queue_full(struct se_cmd *cmd, 
		struct se_device *dev);

static void transport_direct_request_timeout(struct se_cmd *cmd);

static void transport_free_dev_tasks(struct se_cmd *cmd);

static u32 transport_allocate_tasks(struct se_cmd *cmd,

		unsigned long long starting_lba,

		enum dma_data_direction data_direction,

		struct scatterlist *sgl, unsigned int nents);

static int transport_generic_get_mem(struct se_cmd *cmd);

static void transport_put_cmd(struct se_cmd *cmd);

static void transport_remove_cmd_from_queue(struct se_cmd *cmd);
@@ -3666,62 +3662,6 @@ int transport_generic_map_mem_to_cmd( 
}

EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);



static int transport_new_cmd_obj(struct se_cmd *cmd)

{

	struct se_device *dev = cmd->se_dev;

	int set_counts = 1, rc, task_cdbs;



	/*

	 * Setup any BIDI READ tasks and memory from

	 * cmd->t_mem_bidi_list so the READ struct se_tasks

	 * are queued first for the non pSCSI passthrough case.

	 */

	if (cmd->t_bidi_data_sg &&

	    (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV)) {

		rc = transport_allocate_tasks(cmd,

					      cmd->t_task_lba,

					      DMA_FROM_DEVICE,

					      cmd->t_bidi_data_sg,

					      cmd->t_bidi_data_nents);

		if (rc <= 0) {

			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;

			cmd->scsi_sense_reason =

				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

			return -EINVAL;

		}

		atomic_inc(&cmd->t_fe_count);

		atomic_inc(&cmd->t_se_count);

		set_counts = 0;

	}

	/*

	 * Setup the tasks and memory from cmd->t_mem_list

	 * Note for BIDI transfers this will contain the WRITE payload

	 */

	task_cdbs = transport_allocate_tasks(cmd,

					     cmd->t_task_lba,

					     cmd->data_direction,

					     cmd->t_data_sg,

					     cmd->t_data_nents);

	if (task_cdbs <= 0) {

		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;

		cmd->scsi_sense_reason =

			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

		return -EINVAL;

	}



	if (set_counts) {

		atomic_inc(&cmd->t_fe_count);

		atomic_inc(&cmd->t_se_count);

	}



	cmd->t_task_list_num = task_cdbs;



	atomic_set(&cmd->t_task_cdbs_left, task_cdbs);

	atomic_set(&cmd->t_task_cdbs_ex_left, task_cdbs);

	atomic_set(&cmd->t_task_cdbs_timeout_left, task_cdbs);

	return 0;

}



void *transport_kmap_first_data_page(struct se_cmd *cmd)

{

	struct scatterlist *sg = cmd->t_data_sg;
@@ -4000,17 +3940,16 @@ static u32 transport_allocate_tasks( 
}





/*	 transport_generic_new_cmd(): Called from transport_processing_thread()

 *

 *	 Allocate storage transport resources from a set of values predefined

 *	 by transport_generic_cmd_sequencer() from the iSCSI Target RX process.

 *	 Any non zero return here is treated as an "out of resource' op here.

 */

/*

	 * Generate struct se_task(s) and/or their payloads for this CDB.

 * Allocate any required ressources to execute the command, and either place

 * it on the execution queue if possible.  For writes we might not have the

 * payload yet, thus notify the fabric via a call to ->write_pending instead.

 */

int transport_generic_new_cmd(struct se_cmd *cmd)

{

	struct se_device *dev = cmd->se_dev;

	int task_cdbs;

	int set_counts = 1;

	int ret = 0;



	/*
@@ -4024,16 +3963,49 @@ int transport_generic_new_cmd(struct se_cmd *cmd) 
		if (ret < 0)

			return ret;

	}



	/*

	 * Call transport_new_cmd_obj() to invoke transport_allocate_tasks() for

	 * control or data CDB types, and perform the map to backend subsystem

	 * code from SGL memory allocated here by transport_generic_get_mem(), or

	 * via pre-existing SGL memory setup explictly by fabric module code with

	 * transport_generic_map_mem_to_cmd().

	 * Setup any BIDI READ tasks and memory from

	 * cmd->t_mem_bidi_list so the READ struct se_tasks

	 * are queued first for the non pSCSI passthrough case.

	 */

	ret = transport_new_cmd_obj(cmd);

	if (ret < 0)

		return ret;

	if (cmd->t_bidi_data_sg &&

	    (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV)) {

		ret = transport_allocate_tasks(cmd,

					      cmd->t_task_lba,

					      DMA_FROM_DEVICE,

					      cmd->t_bidi_data_sg,

					      cmd->t_bidi_data_nents);

		if (ret <= 0)

			goto out_fail;



		atomic_inc(&cmd->t_fe_count);

		atomic_inc(&cmd->t_se_count);

		set_counts = 0;

	}

	/*

	 * Setup the tasks and memory from cmd->t_mem_list

	 * Note for BIDI transfers this will contain the WRITE payload

	 */

	task_cdbs = transport_allocate_tasks(cmd,

					     cmd->t_task_lba,

					     cmd->data_direction,

					     cmd->t_data_sg,

					     cmd->t_data_nents);

	if (task_cdbs <= 0)

		goto out_fail;



	if (set_counts) {

		atomic_inc(&cmd->t_fe_count);

		atomic_inc(&cmd->t_se_count);

	}



	cmd->t_task_list_num = task_cdbs;



	atomic_set(&cmd->t_task_cdbs_left, task_cdbs);

	atomic_set(&cmd->t_task_cdbs_ex_left, task_cdbs);

	atomic_set(&cmd->t_task_cdbs_timeout_left, task_cdbs);



	/*

	 * For WRITEs, let the fabric know its buffer is ready..

	 * This WRITE struct se_cmd (and all of its associated struct se_task's)
@@ -4051,6 +4023,11 @@ int transport_generic_new_cmd(struct se_cmd *cmd) 
	 */

	transport_execute_tasks(cmd);

	return 0;



out_fail:

	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;

	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	return -EINVAL;

}

EXPORT_SYMBOL(transport_generic_new_cmd);