Commit b92fcfcb authored by David Disseldorp's avatar David Disseldorp Committed by Martin K. Petersen
Browse files

scsi: target: use the stack for XCOPY passthrough cmds 

Reads and writes in the XCOPY loop are synchronous, so needn't be heap
allocated / freed with each loop.

Link: https://lore.kernel.org/r/20200327141954.955-6-ddiss@suse.de


Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Disseldorp <ddiss@suse.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 5f306aff

drivers/target/target_core_xcopy.c

+31 −53
Original line number Diff line number Diff line
@@ -410,7 +410,8 @@ static void xcopy_pt_release_cmd(struct se_cmd *se_cmd) 
	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,

				struct xcopy_pt_cmd, se_cmd);



	kfree(xpt_cmd);

	/* xpt_cmd is on the stack, nothing to free here */

	pr_debug("xpt_cmd done: %p\n", xpt_cmd);

}



static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
@@ -566,20 +567,15 @@ static int target_xcopy_read_source( 
	sector_t src_lba,

	u32 src_sectors)

{

	struct xcopy_pt_cmd *xpt_cmd;

	struct se_cmd *se_cmd;

	struct xcopy_pt_cmd xpt_cmd;

	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;

	u32 length = (src_sectors * src_dev->dev_attrib.block_size);

	int rc;

	unsigned char cdb[16];

	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);



	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);

	if (!xpt_cmd) {

		pr_err("Unable to allocate xcopy_pt_cmd\n");

		return -ENOMEM;

	}

	init_completion(&xpt_cmd->xpt_passthrough_sem);

	se_cmd = &xpt_cmd->se_cmd;

	memset(&xpt_cmd, 0, sizeof(xpt_cmd));

	init_completion(&xpt_cmd.xpt_passthrough_sem);



	memset(&cdb[0], 0, 16);

	cdb[0] = READ_16;
@@ -589,30 +585,26 @@ static int target_xcopy_read_source( 
		(unsigned long long)src_lba, src_sectors, length);



	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,

			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);

	xop->src_pt_cmd = xpt_cmd;

			      DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0]);



	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],

	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],

				remote_port);

	if (rc < 0) {

		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;

		transport_generic_free_cmd(se_cmd, 0);

		return rc;

		ec_cmd->scsi_status = se_cmd->scsi_status;

		goto out;

	}



	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"

		" memory\n", xop->xop_data_sg, xop->xop_data_nents);



	rc = target_xcopy_issue_pt_cmd(xpt_cmd);

	if (rc < 0) {

		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;

	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);

	if (rc < 0)

		ec_cmd->scsi_status = se_cmd->scsi_status;

out:

	transport_generic_free_cmd(se_cmd, 0);

	return rc;

}



	return 0;

}



static int target_xcopy_write_destination(

	struct se_cmd *ec_cmd,

	struct xcopy_op *xop,
@@ -620,20 +612,15 @@ static int target_xcopy_write_destination( 
	sector_t dst_lba,

	u32 dst_sectors)

{

	struct xcopy_pt_cmd *xpt_cmd;

	struct se_cmd *se_cmd;

	struct xcopy_pt_cmd xpt_cmd;

	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;

	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);

	int rc;

	unsigned char cdb[16];

	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);



	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);

	if (!xpt_cmd) {

		pr_err("Unable to allocate xcopy_pt_cmd\n");

		return -ENOMEM;

	}

	init_completion(&xpt_cmd->xpt_passthrough_sem);

	se_cmd = &xpt_cmd->se_cmd;

	memset(&xpt_cmd, 0, sizeof(xpt_cmd));

	init_completion(&xpt_cmd.xpt_passthrough_sem);



	memset(&cdb[0], 0, 16);

	cdb[0] = WRITE_16;
@@ -643,27 +630,23 @@ static int target_xcopy_write_destination( 
		(unsigned long long)dst_lba, dst_sectors, length);



	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,

			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);

	xop->dst_pt_cmd = xpt_cmd;

			      DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0]);



	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],

	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],

				remote_port);

	if (rc < 0) {

		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;

		transport_generic_free_cmd(se_cmd, 0);

		return rc;

		ec_cmd->scsi_status = se_cmd->scsi_status;

		goto out;

	}



	rc = target_xcopy_issue_pt_cmd(xpt_cmd);

	if (rc < 0) {

		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;

	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);

	if (rc < 0)

		ec_cmd->scsi_status = se_cmd->scsi_status;

out:

	transport_generic_free_cmd(se_cmd, 0);

	return rc;

}



	return 0;

}



static void target_xcopy_do_work(struct work_struct *work)

{

	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
@@ -736,10 +719,8 @@ static void target_xcopy_do_work(struct work_struct *work) 


		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,

						dst_lba, cur_nolb);

		if (rc < 0) {

			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);

		if (rc < 0)

			goto out;

		}



		dst_lba += cur_nolb;

		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
@@ -747,9 +728,6 @@ static void target_xcopy_do_work(struct work_struct *work) 


		copied_nolb += cur_nolb;

		nolb -= cur_nolb;



		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);

		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);

	}



	xcopy_pt_undepend_remotedev(xop);

drivers/target/target_core_xcopy.h

+0 −5
Original line number Diff line number Diff line
@@ -18,8 +18,6 @@ enum xcopy_origin_list { 
	XCOL_DEST_RECV_OP = 0x02,

};



struct xcopy_pt_cmd;



struct xcopy_op {

	int op_origin;
@@ -36,9 +34,6 @@ struct xcopy_op { 
	unsigned short dtdi;

	unsigned short nolb;



	struct xcopy_pt_cmd *src_pt_cmd;

	struct xcopy_pt_cmd *dst_pt_cmd;



	u32 xop_data_bytes;

	u32 xop_data_nents;

	struct scatterlist *xop_data_sg;

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