path: root/drivers/target/target_core_fabric_configfs.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
* Filename: target_core_fabric_configfs.c
 *
 * This file contains generic fabric module configfs infrastructure for
 * TCM v4.x code
 *
 * (c) Copyright 2010-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@linux-iscsi.org>
*
 ****************************************************************************/

#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/utsname.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/configfs.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_alua.h"
#include "target_core_pr.h"

#define TF_CIT_SETUP(_name, _item_ops, _group_ops, _attrs)		\
static void target_fabric_setup_##_name##_cit(struct target_fabric_configfs *tf) \
{									\
	struct config_item_type *cit = &tf->tf_##_name##_cit;		\
									\
	cit->ct_item_ops = _item_ops;					\
	cit->ct_group_ops = _group_ops;					\
	cit->ct_attrs = _attrs;						\
	cit->ct_owner = tf->tf_ops->module;				\
	pr_debug("Setup generic %s\n", __stringify(_name));		\
}

#define TF_CIT_SETUP_DRV(_name, _item_ops, _group_ops)		\
static void target_fabric_setup_##_name##_cit(struct target_fabric_configfs *tf) \
{									\
	struct config_item_type *cit = &tf->tf_##_name##_cit;		\
	struct configfs_attribute **attrs = tf->tf_ops->tfc_##_name##_attrs; \
									\
	cit->ct_item_ops = _item_ops;					\
	cit->ct_group_ops = _group_ops;					\
	cit->ct_attrs = attrs;						\
	cit->ct_owner = tf->tf_ops->module;				\
	pr_debug("Setup generic %s\n", __stringify(_name));		\
}

static struct configfs_item_operations target_fabric_port_item_ops;

/* Start of tfc_tpg_mappedlun_cit */

static int target_fabric_mappedlun_link(
	struct config_item *lun_acl_ci,
	struct config_item *lun_ci)
{
	struct se_dev_entry *deve;
	struct se_lun *lun;
	struct se_lun_acl *lacl = container_of(to_config_group(lun_acl_ci),
			struct se_lun_acl, se_lun_group);
	struct se_portal_group *se_tpg;
	struct config_item *nacl_ci, *tpg_ci, *tpg_ci_s, *wwn_ci, *wwn_ci_s;
	bool lun_access_ro;

	if (!lun_ci->ci_type ||
	    lun_ci->ci_type->ct_item_ops != &target_fabric_port_item_ops) {
		pr_err("Bad lun_ci, not a valid lun_ci pointer: %p\n", lun_ci);
		return -EFAULT;
	}
	lun = container_of(to_config_group(lun_ci), struct se_lun, lun_group);

	/*
	 * Ensure that the source port exists
	 */
	if (!lun->lun_se_dev) {
		pr_err("Source se_lun->lun_se_dev does not exist\n");
		return -EINVAL;
	}
	if (lun->lun_shutdown) {
		pr_err("Unable to create mappedlun symlink because"
			" lun->lun_shutdown=true\n");
		return -EINVAL;
	}
	se_tpg = lun->lun_tpg;

	nacl_ci = &lun_acl_ci->ci_parent->ci_group->cg_item;
	tpg_ci = &nacl_ci->ci_group->cg_item;
	wwn_ci = &tpg_ci->ci_group->cg_item;
	tpg_ci_s = &lun_ci->ci_parent->ci_group->cg_item;
	wwn_ci_s = &tpg_ci_s->ci_group->cg_item;
	/*
	 * Make sure the SymLink is going to the same $FABRIC/$WWN/tpgt_$TPGT
	 */
	if (strcmp(config_item_name(wwn_ci), config_item_name(wwn_ci_s))) {
		pr_err("Illegal Initiator ACL SymLink outside of %s\n",
			config_item_name(wwn_ci));
		return -EINVAL;
	}
	if (strcmp(config_item_name(tpg_ci), config_item_name(tpg_ci_s))) {
		pr_err("Illegal Initiator ACL Symlink outside of %s"
			" TPGT: %s\n", config_item_name(wwn_ci),
			config_item_name(tpg_ci));
		return -EINVAL;
	}
	/*
	 * If this struct se_node_acl was dynamically generated with
	 * tpg_1/attrib/generate_node_acls=1, use the existing
	 * deve->lun_access_ro value, which will be true when
	 * tpg_1/attrib/demo_mode_write_protect=1
	 */
	rcu_read_lock();
	deve = target_nacl_find_deve(lacl->se_lun_nacl, lacl->mapped_lun);
	if (deve)
		lun_access_ro = deve->lun_access_ro;
	else
		lun_access_ro =
			(se_tpg->se_tpg_tfo->tpg_check_prod_mode_write_protect(
				se_tpg)) ? true : false;
	rcu_read_unlock();
	/*
	 * Determine the actual mapped LUN value user wants..
	 *
	 * This value is what the SCSI Initiator actually sees the
	 * $FABRIC/$WWPN/$TPGT/lun/lun_* as on their SCSI Initiator Ports.
	 */
	return core_dev_add_initiator_node_lun_acl(se_tpg, lacl, lun, lun_access_ro);
}

static void target_fabric_mappedlun_unlink(
	struct config_item *lun_acl_ci,
	struct config_item *lun_ci)
{
	struct se_lun_acl *lacl = container_of