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Commit f872c9f4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Nicholas Bellinger
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tcm_loop: kill tcm_loop_allocate_core_cmd 



This function makes little sense as a separate abstraction as it's deeply
interwinded with the control flow of its only caller.  Merged it into
tcm_loop_queuecommand after factoring out a helper to convert the task
attribute representation.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 59dcb5ec

drivers/target/loopback/tcm_loop.c

+59 −88
Original line number Diff line number Diff line
@@ -48,81 +48,6 @@ static struct kmem_cache *tcm_loop_cmd_cache; 


static int tcm_loop_hba_no_cnt;



/*

 * Allocate a tcm_loop cmd descriptor from target_core_mod code

 *

 * Can be called from interrupt context in tcm_loop_queuecommand() below

 */

static struct se_cmd *tcm_loop_allocate_core_cmd(

	struct tcm_loop_hba *tl_hba,

	struct se_portal_group *se_tpg,

	struct scsi_cmnd *sc)

{

	struct se_cmd *se_cmd;

	struct se_session *se_sess;

	struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;

	struct tcm_loop_cmd *tl_cmd;

	int sam_task_attr;



	if (!tl_nexus) {

		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"

				" does not exist\n");

		set_host_byte(sc, DID_ERROR);

		return NULL;

	}

	se_sess = tl_nexus->se_sess;



	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);

	if (!tl_cmd) {

		pr_err("Unable to allocate struct tcm_loop_cmd\n");

		set_host_byte(sc, DID_ERROR);

		return NULL;

	}

	se_cmd = &tl_cmd->tl_se_cmd;

	/*

	 * Save the pointer to struct scsi_cmnd *sc

	 */

	tl_cmd->sc = sc;

	/*

	 * Locate the SAM Task Attr from struct scsi_cmnd *

	 */

	if (sc->device->tagged_supported) {

		switch (sc->tag) {

		case HEAD_OF_QUEUE_TAG:

			sam_task_attr = MSG_HEAD_TAG;

			break;

		case ORDERED_QUEUE_TAG:

			sam_task_attr = MSG_ORDERED_TAG;

			break;

		default:

			sam_task_attr = MSG_SIMPLE_TAG;

			break;

		}

	} else

		sam_task_attr = MSG_SIMPLE_TAG;



	/*

	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure

	 */

	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,

			scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,

			&tl_cmd->tl_sense_buf[0]);



	if (scsi_bidi_cmnd(sc))

		se_cmd->se_cmd_flags |= SCF_BIDI;



	/*

	 * Locate the struct se_lun pointer and attach it to struct se_cmd

	 */

	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {

		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);

		set_host_byte(sc, DID_NO_CONNECT);

		return NULL;

	}



	return se_cmd;

}



/*

 * Called by struct target_core_fabric_ops->new_cmd_map()

 *
@@ -262,6 +187,25 @@ static int tcm_loop_change_queue_depth( 
	return sdev->queue_depth;

}



/*

 * Locate the SAM Task Attr from struct scsi_cmnd *

 */

static int tcm_loop_sam_attr(struct scsi_cmnd *sc)

{

	if (sc->device->tagged_supported) {

		switch (sc->tag) {

		case HEAD_OF_QUEUE_TAG:

			return MSG_HEAD_TAG;

		case ORDERED_QUEUE_TAG:

			return MSG_ORDERED_TAG;

		default:

			break;

		}

	}



	return MSG_SIMPLE_TAG;

}



/*

 * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data

 * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
@@ -274,6 +218,10 @@ static int tcm_loop_queuecommand( 
	struct se_portal_group *se_tpg;

	struct tcm_loop_hba *tl_hba;

	struct tcm_loop_tpg *tl_tpg;

	struct se_session *se_sess;

	struct tcm_loop_nexus *tl_nexus;

	struct tcm_loop_cmd *tl_cmd;





	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"

		" scsi_buf_len: %u\n", sc->device->host->host_no,
@@ -290,24 +238,47 @@ static int tcm_loop_queuecommand( 
	 */

	if (!tl_tpg->tl_hba) {

		set_host_byte(sc, DID_NO_CONNECT);

		sc->scsi_done(sc);

		return 0;

		goto out_done;

	}

	se_tpg = &tl_tpg->tl_se_tpg;

	/*

	 * Determine the SAM Task Attribute and allocate tl_cmd and

	 * tl_cmd->tl_se_cmd from TCM infrastructure

	 */

	se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);

	if (!se_cmd) {

		sc->scsi_done(sc);

		return 0;



	tl_nexus = tl_hba->tl_nexus;

	if (!tl_nexus) {

		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"

				" does not exist\n");

		set_host_byte(sc, DID_ERROR);

		goto out_done;

	}

	/*

	 * Queue up the newly allocated to be processed in TCM thread context.

	*/

	se_sess = tl_nexus->se_sess;



	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);

	if (!tl_cmd) {

		pr_err("Unable to allocate struct tcm_loop_cmd\n");

		set_host_byte(sc, DID_ERROR);

		goto out_done;

	}

	se_cmd = &tl_cmd->tl_se_cmd;

	tl_cmd->sc = sc;



	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,

			scsi_bufflen(sc), sc->sc_data_direction,

			tcm_loop_sam_attr(sc), &tl_cmd->tl_sense_buf[0]);



	if (scsi_bidi_cmnd(sc))

		se_cmd->se_cmd_flags |= SCF_BIDI;



	if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {

		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);

		set_host_byte(sc, DID_NO_CONNECT);

		goto out_done;

	}



	transport_generic_handle_cdb_map(se_cmd);

	return 0;



out_done:

	sc->scsi_done(sc);

	return 0;

}



/*