static void target_xcopy_do_work()

in target_core_xcopy.c [667:782]

• 84 lines of code
• 9 McCabe index (conditional complexity)

static void target_xcopy_do_work(struct work_struct *work)
{
	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
	struct se_cmd *ec_cmd = xop->xop_se_cmd;
	struct se_device *src_dev, *dst_dev;
	sector_t src_lba, dst_lba, end_lba;
	unsigned int max_sectors;
	int rc = 0;
	unsigned short nolb, max_nolb, copied_nolb = 0;
	sense_reason_t sense_rc;

	sense_rc = target_parse_xcopy_cmd(xop);
	if (sense_rc != TCM_NO_SENSE)
		goto err_free;

	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
		sense_rc = TCM_INVALID_PARAMETER_LIST;
		goto err_free;
	}

	src_dev = xop->src_dev;
	dst_dev = xop->dst_dev;
	src_lba = xop->src_lba;
	dst_lba = xop->dst_lba;
	nolb = xop->nolb;
	end_lba = src_lba + nolb;
	/*
	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
	 * smallest max_sectors between src_dev + dev_dev, or
	 */
	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
			  dst_dev->dev_attrib.hw_max_sectors);
	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);

	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));

	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
			nolb, max_nolb, (unsigned long long)end_lba);
	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
			(unsigned long long)src_lba, (unsigned long long)dst_lba);

	while (src_lba < end_lba) {
		unsigned short cur_nolb = min(nolb, max_nolb);
		u32 cur_bytes = cur_nolb * src_dev->dev_attrib.block_size;

		if (cur_bytes != xop->xop_data_bytes) {
			/*
			 * (Re)allocate a buffer large enough to hold the XCOPY
			 * I/O size, which can be reused each read / write loop.
			 */
			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
			rc = target_alloc_sgl(&xop->xop_data_sg,
					      &xop->xop_data_nents,
					      cur_bytes,
					      false, false);
			if (rc < 0)
				goto out;
			xop->xop_data_bytes = cur_bytes;
		}

		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);

		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
		if (rc < 0)
			goto out;

		src_lba += cur_nolb;
		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
				(unsigned long long)src_lba);

		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);

		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
						dst_lba, cur_nolb);
		if (rc < 0)
			goto out;

		dst_lba += cur_nolb;
		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
				(unsigned long long)dst_lba);

		copied_nolb += cur_nolb;
		nolb -= cur_nolb;
	}

	xcopy_pt_undepend_remotedev(xop);
	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
	kfree(xop);

	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
		(unsigned long long)src_lba, (unsigned long long)dst_lba);
	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);

	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
	return;

out:
	/*
	 * The XCOPY command was aborted after some data was transferred.
	 * Terminate command with CHECK CONDITION status, with the sense key
	 * set to COPY ABORTED.
	 */
	sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
	xcopy_pt_undepend_remotedev(xop);
	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);

err_free:
	kfree(xop);
	pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
			   rc, sense_rc);
	target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
}