path: root/drivers/target/target_core_xcopy.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * Filename: target_core_xcopy.c
 *
 * This file contains support for SPC-4 Extended-Copy offload with generic
 * TCM backends.
 *
 * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
 *
 * Author:
 * Nicholas A. Bellinger <nab@daterainc.com>
 *
 ******************************************************************************/

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/configfs.h>
#include <linux/ratelimit.h>
#include <scsi/scsi_proto.h>
#include <asm/unaligned.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>

#include "target_core_internal.h"
#include "target_core_pr.h"
#include "target_core_ua.h"
#include "target_core_xcopy.h"

static struct workqueue_struct *xcopy_wq = NULL;

static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop);

/**
 * target_xcopy_locate_se_dev_e4_iter - compare XCOPY NAA device identifiers
 *
 * @se_dev: device being considered for match
 * @dev_wwn: XCOPY requested NAA dev_wwn
 * @return: 1 on match, 0 on no-match
 */
static int target_xcopy_locate_se_dev_e4_iter(struct se_device *se_dev,
					      const unsigned char *dev_wwn)
{
	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
	int rc;

	if (!se_dev->dev_attrib.emulate_3pc) {
		pr_debug("XCOPY: emulate_3pc disabled on se_dev %p\n", se_dev);
		return 0;
	}

	memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
	spc_gen_naa_6h_vendor_specific(se_dev, &tmp_dev_wwn[0]);

	rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
	if (rc != 0) {
		pr_debug("XCOPY: skip non-matching: %*ph\n",
			 XCOPY_NAA_IEEE_REGEX_LEN, tmp_dev_wwn);
		return 0;
	}
	pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);

	return 1;
}

static int target_xcopy_locate_se_dev_e4(struct se_session *sess,
					const unsigned char *dev_wwn,
					struct se_device **_found_dev,
					struct percpu_ref **_found_lun_ref)
{
	struct se_dev_entry *deve;
	struct se_node_acl *nacl;
	struct se_lun *this_lun = NULL;
	struct se_device *found_dev = NULL;

	/* cmd with NULL sess indicates no associated $FABRIC_MOD */
	if (!sess)
		goto err_out;

	pr_debug("XCOPY 0xe4: searching for: %*ph\n",
		 XCOPY_NAA_IEEE_REGEX_LEN, dev_wwn);

	nacl = sess->se_node_acl;
	rcu_read_lock();
	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
		struct se_device *this_dev;
		int rc;

		this_lun = deve->se_lun;
		this_dev = rcu_dereference_raw(this_lun->lun_se_dev);

		rc = target_xcopy_locate_se_dev_e4_iter(this_dev, dev_wwn);
		if (rc) {
			if (percpu_ref_tryget_live(&this_lun->lun_ref))
				found_dev = this_dev;
			break;
		}
	}
	rcu_read_unlock();
	if (found_dev == NULL)
		goto err_out;

	pr_debug("lun_ref held for se_dev: %p se_dev->se_dev_group: %p\n",
		 found_dev, &found_dev->dev_group);
	*_found_dev = found_dev;
	*_found_lun_ref = &this_lun->lun_ref;
	return 0;
err_out:
	pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
	return -EINVAL;
}

static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
				unsigned char *p, unsigned short cscd_index)
{
	unsigned char *desc = p;
	unsigned short ript;
	u8 desig_len;
	/*
	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
	 */
	ript = get_unaligned_be16(&desc[2]);
	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
	/*
	 * Check for supported code set, association, and designator type
	 */
	if ((desc[4] & 0x0f) != 0x1) {
		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
		return -EINVAL;
	}
	if ((desc[5] & 0x30) != 0x00) {
		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
		return -EINVAL;
	}
	if ((desc[5] & 0x0f) != 0x3) {
		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
				(desc[5] & 0x0f));
		return -EINVAL;
	}
	/*
	 * Check for matching 16 byte length for NAA IEEE Registered Extended
	 * Assigned designator
	 */
	desig_len = desc[7];
	if (desig_len != XCOPY_NAA_IEEE_REGEX_LEN) {
		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
		return -EINVAL;
	}
	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
	/*
	 * Check for NAA IEEE Registered Extended Assigned header..
	 */
	if ((desc[8] & 0xf0) != 0x60) {
		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
					(desc[8] & 0xf0));
		return -EINVAL;
	}

	if (cscd_index != xop->stdi && cscd_index != xop->dtdi) {
		pr_debug("XCOPY 0xe4: ignoring CSCD entry %d - neither src nor "
			 "dest\n", cscd_index);
		return 0;
	}

	if (cscd_index == xop->stdi) {
		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
		/*
		 * Determine if the source designator matches the local device
		 */
		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[</