text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*******************************************************************************
   * Filename:  target_core_device.c (based on iscsi_target_device.c)
   *
   * This file contains the TCM Virtual Device and Disk Transport
   * agnostic related functions.
   *
   * (c) Copyright 2003-2013 Datera, Inc.
   *
   * Nicholas A. Bellinger <nab@kernel.org>
   *
   ******************************************************************************/
  
  #include <linux/net.h>
  #include <linux/string.h>
  #include <linux/delay.h>
  #include <linux/timer.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/kthread.h>
  #include <linux/in.h>
  #include <linux/export.h>
  #include <linux/t10-pi.h>
  #include <asm/unaligned.h>
  #include <net/sock.h>
  #include <net/tcp.h>
  #include <scsi/scsi_common.h>
  #include <scsi/scsi_proto.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"
  #include "target_core_ua.h"
  
  static DEFINE_MUTEX(device_mutex);
  static LIST_HEAD(device_list);
  static DEFINE_IDR(devices_idr);
  
  static struct se_hba *lun0_hba;
  /* not static, needed by tpg.c */
  struct se_device *g_lun0_dev;
  
  sense_reason_t
  transport_lookup_cmd_lun(struct se_cmd *se_cmd)
  {
  	struct se_lun *se_lun = NULL;
  	struct se_session *se_sess = se_cmd->se_sess;
  	struct se_node_acl *nacl = se_sess->se_node_acl;
  	struct se_dev_entry *deve;
  	sense_reason_t ret = TCM_NO_SENSE;
  
  	rcu_read_lock();
  	deve = target_nacl_find_deve(nacl, se_cmd->orig_fe_lun);
  	if (deve) {
  		atomic_long_inc(&deve->total_cmds);
  
  		if (se_cmd->data_direction == DMA_TO_DEVICE)
  			atomic_long_add(se_cmd->data_length,
  					&deve->write_bytes);
  		else if (se_cmd->data_direction == DMA_FROM_DEVICE)
  			atomic_long_add(se_cmd->data_length,
  					&deve->read_bytes);
  
  		if ((se_cmd->data_direction == DMA_TO_DEVICE) &&
  		    deve->lun_access_ro) {
  			pr_err("TARGET_CORE[%s]: Detected WRITE_PROTECTED LUN"
  				" Access for 0x%08llx\n",
  				se_cmd->se_tfo->fabric_name,
  				se_cmd->orig_fe_lun);
  			rcu_read_unlock();
  			return TCM_WRITE_PROTECTED;
  		}
  
  		se_lun = rcu_dereference(deve->se_lun);
  
  		if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
  			se_lun = NULL;
  			goto out_unlock;
  		}
  
  		se_cmd->se_lun = se_lun;
  		se_cmd->pr_res_key = deve->pr_res_key;
  		se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
  		se_cmd->lun_ref_active = true;
  	}
  out_unlock:
  	rcu_read_unlock();
  
  	if (!se_lun) {
  		/*
  		 * Use the se_portal_group->tpg_virt_lun0 to allow for
  		 * REPORT_LUNS, et al to be returned when no active
  		 * MappedLUN=0 exists for this Initiator Port.
  		 */
  		if (se_cmd->orig_fe_lun != 0) {
  			pr_err("TARGET_CORE[%s]: Detected NON_EXISTENT_LUN"
  				" Access for 0x%08llx from %s\n",
  				se_cmd->se_tfo->fabric_name,
  				se_cmd->orig_fe_lun,
  				nacl->initiatorname);
  			return TCM_NON_EXISTENT_LUN;
  		}
  
  		/*
  		 * Force WRITE PROTECT for virtual LUN 0
  		 */
  		if ((se_cmd->data_direction != DMA_FROM_DEVICE) &&
  		    (se_cmd->data_direction != DMA_NONE))
  			return TCM_WRITE_PROTECTED;
  
  		se_lun = se_sess->se_tpg->tpg_virt_lun0;
  		if (!percpu_ref_tryget_live(&se_lun->lun_ref))
  			return TCM_NON_EXISTENT_LUN;
  
  		se_cmd->se_lun = se_sess->se_tpg->tpg_virt_lun0;
  		se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
  		se_cmd->lun_ref_active = true;
  	}
  	/*
  	 * RCU reference protected by percpu se_lun->lun_ref taken above that
  	 * must drop to zero (including initial reference) before this se_lun
  	 * pointer can be kfree_rcu() by the final se_lun->lun_group put via
  	 * target_core_fabric_configfs.c:target_fabric_port_release
  	 */
  	se_cmd->se_dev = rcu_dereference_raw(se_lun->lun_se_dev);
  	atomic_long_inc(&se_cmd->se_dev->num_cmds);
  
  	if (se_cmd->data_direction == DMA_TO_DEVICE)
  		atomic_long_add(se_cmd->data_length,
  				&se_cmd->se_dev->write_bytes);
  	else if (se_cmd->data_direction == DMA_FROM_DEVICE)
  		atomic_long_add(se_cmd->data_length,
  				&se_cmd->se_dev->read_bytes);
  
  	return ret;
  }
  EXPORT_SYMBOL(transport_lookup_cmd_lun);
  
  int transport_lookup_tmr_lun(struct se_cmd *se_cmd)
  {
  	struct se_dev_entry *deve;
  	struct se_lun *se_lun = NULL;
  	struct se_session *se_sess = se_cmd->se_sess;
  	struct se_node_acl *nacl = se_sess->se_node_acl;
  	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
  	unsigned long flags;
  
  	rcu_read_lock();
  	deve = target_nacl_find_deve(nacl, se_cmd->orig_fe_lun);
  	if (deve) {
  		se_lun = rcu_dereference(deve->se_lun);
  
  		if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
  			se_lun = NULL;
  			goto out_unlock;
  		}
  
  		se_cmd->se_lun = se_lun;
  		se_cmd->pr_res_key = deve->pr_res_key;
  		se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
  		se_cmd->lun_ref_active = true;
  	}
  out_unlock:
  	rcu_read_unlock();
  
  	if (!se_lun) {
  		pr_debug("TARGET_CORE[%s]: Detected NON_EXISTENT_LUN"
  			" Access for 0x%08llx for %s\n",
  			se_cmd->se_tfo->fabric_name,
  			se_cmd->orig_fe_lun,
  			nacl->initiatorname);
  		return -ENODEV;
  	}
  	se_cmd->se_dev = rcu_dereference_raw(se_lun->lun_se_dev);
  	se_tmr->tmr_dev = rcu_dereference_raw(se_lun->lun_se_dev);
  
  	spin_lock_irqsave(&se_tmr->tmr_dev->se_tmr_lock, flags);
  	list_add_tail(&se_tmr->tmr_list, &se_tmr->tmr_dev->dev_tmr_list);
  	spin_unlock_irqrestore(&se_tmr->tmr_dev->se_tmr_lock, flags);
  
  	return 0;
  }
  EXPORT_SYMBOL(transport_lookup_tmr_lun);
  
  bool target_lun_is_rdonly(struct se_cmd *cmd)
  {
  	struct se_session *se_sess = cmd->se_sess;
  	struct se_dev_entry *deve;
  	bool ret;
  
  	rcu_read_lock();
  	deve = target_nacl_find_deve(se_sess->se_node_acl, cmd->orig_fe_lun);
  	ret = deve && deve->lun_access_ro;
  	rcu_read_unlock();
  
  	return ret;
  }
  EXPORT_SYMBOL(target_lun_is_rdonly);
  
  /*
   * This function is called from core_scsi3_emulate_pro_register_and_move()
   * and core_scsi3_decode_spec_i_port(), and will increment &deve->pr_kref
   * when a matching rtpi is found.
   */
  struct se_dev_entry *core_get_se_deve_from_rtpi(
  	struct se_node_acl *nacl,
  	u16 rtpi)
  {
  	struct se_dev_entry *deve;
  	struct se_lun *lun;
  	struct se_portal_group *tpg = nacl->se_tpg;
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
  		lun = rcu_dereference(deve->se_lun);
  		if (!lun) {
  			pr_err("%s device entries device pointer is"
  				" NULL, but Initiator has access.\n",
  				tpg->se_tpg_tfo->fabric_name);
  			continue;
  		}
  		if (lun->lun_rtpi != rtpi)
  			continue;
  
  		kref_get(&deve->pr_kref);
  		rcu_read_unlock();
  
  		return deve;
  	}
  	rcu_read_unlock();
  
  	return NULL;
  }
  
  void core_free_device_list_for_node(
  	struct se_node_acl *nacl,
  	struct se_portal_group *tpg)
  {
  	struct se_dev_entry *deve;
  
  	mutex_lock(&nacl->lun_entry_mutex);
  	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
  		struct se_lun *lun = rcu_dereference_check(deve->se_lun,
  					lockdep_is_held(&nacl->lun_entry_mutex));
  		core_disable_device_list_for_node(lun, deve, nacl, tpg);
  	}
  	mutex_unlock(&nacl->lun_entry_mutex);
  }
  
  void core_update_device_list_access(
  	u64 mapped_lun,
  	bool lun_access_ro,
  	struct se_node_acl *nacl)
  {
  	struct se_dev_entry *deve;
  
  	mutex_lock(&nacl->lun_entry_mutex);
  	deve = target_nacl_find_deve(nacl, mapped_lun);
  	if (deve)
  		deve->lun_access_ro = lun_access_ro;
  	mutex_unlock(&nacl->lun_entry_mutex);
  }
  
  /*
   * Called with rcu_read_lock or nacl->device_list_lock held.
   */
  struct se_dev_entry *target_nacl_find_deve(struct se_node_acl *nacl, u64 mapped_lun)
  {
  	struct se_dev_entry *deve;
  
  	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
  		if (deve->mapped_lun == mapped_lun)
  			return deve;
  
  	return NULL;
  }
  EXPORT_SYMBOL(target_nacl_find_deve);
  
  void target_pr_kref_release(struct kref *kref)
  {
  	struct se_dev_entry *deve = container_of(kref, struct se_dev_entry,
  						 pr_kref);
  	complete(&deve->pr_comp);
  }
  
  static void
  target_luns_data_has_changed(struct se_node_acl *nacl, struct se_dev_entry *new,
  			     bool skip_new)
  {
  	struct se_dev_entry *tmp;
  
  	rcu_read_lock();
  	hlist_for_each_entry_rcu(tmp, &nacl->lun_entry_hlist, link) {
  		if (skip_new && tmp == new)
  			continue;
  		core_scsi3_ua_allocate(tmp, 0x3F,
  				       ASCQ_3FH_REPORTED_LUNS_DATA_HAS_CHANGED);
  	}
  	rcu_read_unlock();
  }
  
  int core_enable_device_list_for_node(
  	struct se_lun *lun,
  	struct se_lun_acl *lun_acl,
  	u64 mapped_lun,
  	bool lun_access_ro,
  	struct se_node_acl *nacl,
  	struct se_portal_group *tpg)
  {
  	struct se_dev_entry *orig, *new;
  
  	new = kzalloc(sizeof(*new), GFP_KERNEL);
  	if (!new) {
  		pr_err("Unable to allocate se_dev_entry memory\n");
  		return -ENOMEM;
  	}
  
  	spin_lock_init(&new->ua_lock);
  	INIT_LIST_HEAD(&new->ua_list);
  	INIT_LIST_HEAD(&new->lun_link);
  
  	new->mapped_lun = mapped_lun;
  	kref_init(&new->pr_kref);
  	init_completion(&new->pr_comp);
  
  	new->lun_access_ro = lun_access_ro;
  	new->creation_time = get_jiffies_64();
  	new->attach_count++;
  
  	mutex_lock(&nacl->lun_entry_mutex);
  	orig = target_nacl_find_deve(nacl, mapped_lun);
  	if (orig && orig->se_lun) {
  		struct se_lun *orig_lun = rcu_dereference_check(orig->se_lun,
  					lockdep_is_held(&nacl->lun_entry_mutex));
  
  		if (orig_lun != lun) {
  			pr_err("Existing orig->se_lun doesn't match new lun"
  			       " for dynamic -> explicit NodeACL conversion:"
  				" %s\n", nacl->initiatorname);
  			mutex_unlock(&nacl->lun_entry_mutex);
  			kfree(new);
  			return -EINVAL;
  		}
  		if (orig->se_lun_acl != NULL) {
  			pr_warn_ratelimited("Detected existing explicit"
  				" se_lun_acl->se_lun_group reference for %s"
  				" mapped_lun: %llu, failing\n",
  				 nacl->initiatorname, mapped_lun);
  			mutex_unlock(&nacl->lun_entry_mutex);
  			kfree(new);
  			return -EINVAL;
  		}
  
  		rcu_assign_pointer(new->se_lun, lun);
  		rcu_assign_pointer(new->se_lun_acl, lun_acl);
  		hlist_del_rcu(&orig->link);
  		hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
  		mutex_unlock(&nacl->lun_entry_mutex);
  
  		spin_lock(&lun->lun_deve_lock);
  		list_del(&orig->lun_link);
  		list_add_tail(&new->lun_link, &lun->lun_deve_list);
  		spin_unlock(&lun->lun_deve_lock);
  
  		kref_put(&orig->pr_kref, target_pr_kref_release);
  		wait_for_completion(&orig->pr_comp);
  
  		target_luns_data_has_changed(nacl, new, true);
  		kfree_rcu(orig, rcu_head);
  		return 0;
  	}
  
  	rcu_assign_pointer(new->se_lun, lun);
  	rcu_assign_pointer(new->se_lun_acl, lun_acl);
  	hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
  	mutex_unlock(&nacl->lun_entry_mutex);
  
  	spin_lock(&lun->lun_deve_lock);
  	list_add_tail(&new->lun_link, &lun->lun_deve_list);
  	spin_unlock(&lun->lun_deve_lock);
  
  	target_luns_data_has_changed(nacl, new, true);
  	return 0;
  }
  
  void core_disable_device_list_for_node(
  	struct se_lun *lun,
  	struct se_dev_entry *orig,
  	struct se_node_acl *nacl,
  	struct se_portal_group *tpg)
  {
  	/*
  	 * rcu_dereference_raw protected by se_lun->lun_group symlink
  	 * reference to se_device->dev_group.
  	 */
  	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
  
  	lockdep_assert_held(&nacl->lun_entry_mutex);
  
  	/*
  	 * If the MappedLUN entry is being disabled, the entry in
  	 * lun->lun_deve_list must be removed now before clearing the
  	 * struct se_dev_entry pointers below as logic in
  	 * core_alua_do_transition_tg_pt() depends on these being present.
  	 *
  	 * deve->se_lun_acl will be NULL for demo-mode created LUNs
  	 * that have not been explicitly converted to MappedLUNs ->
  	 * struct se_lun_acl, but we remove deve->lun_link from
  	 * lun->lun_deve_list. This also means that active UAs and
  	 * NodeACL context specific PR metadata for demo-mode
  	 * MappedLUN *deve will be released below..
  	 */
  	spin_lock(&lun->lun_deve_lock);
  	list_del(&orig->lun_link);
  	spin_unlock(&lun->lun_deve_lock);
  	/*
  	 * Disable struct se_dev_entry LUN ACL mapping
  	 */
  	core_scsi3_ua_release_all(orig);
  
  	hlist_del_rcu(&orig->link);
  	clear_bit(DEF_PR_REG_ACTIVE, &orig->deve_flags);
  	orig->lun_access_ro = false;
  	orig->creation_time = 0;
  	orig->attach_count--;
  	/*
  	 * Before firing off RCU callback, wait for any in process SPEC_I_PT=1
  	 * or REGISTER_AND_MOVE PR operation to complete.
  	 */
  	kref_put(&orig->pr_kref, target_pr_kref_release);
  	wait_for_completion(&orig->pr_comp);
  
  	rcu_assign_pointer(orig->se_lun, NULL);
  	rcu_assign_pointer(orig->se_lun_acl, NULL);
  
  	kfree_rcu(orig, rcu_head);
  
  	core_scsi3_free_pr_reg_from_nacl(dev, nacl);
  	target_luns_data_has_changed(nacl, NULL, false);
  }
  
  /*      core_clear_lun_from_tpg():
   *
   *
   */
  void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
  {
  	struct se_node_acl *nacl;
  	struct se_dev_entry *deve;
  
  	mutex_lock(&tpg->acl_node_mutex);
  	list_for_each_entry(nacl, &tpg->acl_node_list, acl_list) {
  
  		mutex_lock(&nacl->lun_entry_mutex);
  		hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
  			struct se_lun *tmp_lun = rcu_dereference_check(deve->se_lun,
  					lockdep_is_held(&nacl->lun_entry_mutex));
  
  			if (lun != tmp_lun)
  				continue;
  
  			core_disable_device_list_for_node(lun, deve, nacl, tpg);
  		}
  		mutex_unlock(&nacl->lun_entry_mutex);
  	}
  	mutex_unlock(&tpg->acl_node_mutex);
  }
  
  int core_alloc_rtpi(struct se_lun *lun, struct se_device *dev)
  {
  	struct se_lun *tmp;
  
  	spin_lock(&dev->se_port_lock);
  	if (dev->export_count == 0x0000ffff) {
  		pr_warn("Reached dev->dev_port_count =="
  				" 0x0000ffff\n");
  		spin_unlock(&dev->se_port_lock);
  		return -ENOSPC;
  	}
  again:
  	/*
  	 * Allocate the next RELATIVE TARGET PORT IDENTIFIER for this struct se_device
  	 * Here is the table from spc4r17 section 7.7.3.8.
  	 *
  	 *    Table 473 -- RELATIVE TARGET PORT IDENTIFIER field
  	 *
  	 * Code      Description
  	 * 0h        Reserved
  	 * 1h        Relative port 1, historically known as port A
  	 * 2h        Relative port 2, historically known as port B
  	 * 3h to FFFFh    Relative port 3 through 65 535
  	 */
  	lun->lun_rtpi = dev->dev_rpti_counter++;
  	if (!lun->lun_rtpi)
  		goto again;
  
  	list_for_each_entry(tmp, &dev->dev_sep_list, lun_dev_link) {
  		/*
  		 * Make sure RELATIVE TARGET PORT IDENTIFIER is unique
  		 * for 16-bit wrap..
  		 */
  		if (lun->lun_rtpi == tmp->lun_rtpi)
  			goto again;
  	}
  	spin_unlock(&dev->se_port_lock);
  
  	return 0;
  }
  
  static void se_release_vpd_for_dev(struct se_device *dev)
  {
  	struct t10_vpd *vpd, *vpd_tmp;
  
  	spin_lock(&dev->t10_wwn.t10_vpd_lock);
  	list_for_each_entry_safe(vpd, vpd_tmp,
  			&dev->t10_wwn.t10_vpd_list, vpd_list) {
  		list_del(&vpd->vpd_list);
  		kfree(vpd);
  	}
  	spin_unlock(&dev->t10_wwn.t10_vpd_lock);
  }
  
  static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
  {
  	u32 aligned_max_sectors;
  	u32 alignment;
  	/*
  	 * Limit max_sectors to a PAGE_SIZE aligned value for modern
  	 * transport_allocate_data_tasks() operation.
  	 */
  	alignment = max(1ul, PAGE_SIZE / block_size);
  	aligned_max_sectors = rounddown(max_sectors, alignment);
  
  	if (max_sectors != aligned_max_sectors)
  		pr_info("Rounding down aligned max_sectors from %u to %u\n",
  			max_sectors, aligned_max_sectors);
  
  	return aligned_max_sectors;
  }
  
  int core_dev_add_lun(
  	struct se_portal_group *tpg,
  	struct se_device *dev,
  	struct se_lun *lun)
  {
  	int rc;
  
  	rc = core_tpg_add_lun(tpg, lun, false, dev);
  	if (rc < 0)
  		return rc;
  
  	pr_debug("%s_TPG[%u]_LUN[%llu] - Activated %s Logical Unit from"
  		" CORE HBA: %u\n", tpg->se_tpg_tfo->fabric_name,
  		tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
  		tpg->se_tpg_tfo->fabric_name, dev->se_hba->hba_id);
  	/*
  	 * Update LUN maps for dynamically added initiators when
  	 * generate_node_acl is enabled.
  	 */
  	if (tpg->se_tpg_tfo->tpg_check_demo_mode(tpg)) {
  		struct se_node_acl *acl;
  
  		mutex_lock(&tpg->acl_node_mutex);
  		list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  			if (acl->dynamic_node_acl &&
  			    (!tpg->se_tpg_tfo->tpg_check_demo_mode_login_only ||
  			     !tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg))) {
  				core_tpg_add_node_to_devs(acl, tpg, lun);
  			}
  		}
  		mutex_unlock(&tpg->acl_node_mutex);
  	}
  
  	return 0;
  }
  
  /*      core_dev_del_lun():
   *
   *
   */
  void core_dev_del_lun(
  	struct se_portal_group *tpg,
  	struct se_lun *lun)
  {
  	pr_debug("%s_TPG[%u]_LUN[%llu] - Deactivating %s Logical Unit from"
  		" device object\n", tpg->se_tpg_tfo->fabric_name,
  		tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
  		tpg->se_tpg_tfo->fabric_name);
  
  	core_tpg_remove_lun(tpg, lun);
  }
  
  struct se_lun_acl *core_dev_init_initiator_node_lun_acl(
  	struct se_portal_group *tpg,
  	struct se_node_acl *nacl,
  	u64 mapped_lun,
  	int *ret)
  {
  	struct se_lun_acl *lacl;
  
  	if (strlen(nacl->initiatorname) >= TRANSPORT_IQN_LEN) {
  		pr_err("%s InitiatorName exceeds maximum size.\n",
  			tpg->se_tpg_tfo->fabric_name);
  		*ret = -EOVERFLOW;
  		return NULL;
  	}
  	lacl = kzalloc(sizeof(struct se_lun_acl), GFP_KERNEL);
  	if (!lacl) {
  		pr_err("Unable to allocate memory for struct se_lun_acl.\n");
  		*ret = -ENOMEM;
  		return NULL;
  	}
  
  	lacl->mapped_lun = mapped_lun;
  	lacl->se_lun_nacl = nacl;
  
  	return lacl;
  }
  
  int core_dev_add_initiator_node_lun_acl(
  	struct se_portal_group *tpg,
  	struct se_lun_acl *lacl,
  	struct se_lun *lun,
  	bool lun_access_ro)
  {
  	struct se_node_acl *nacl = lacl->se_lun_nacl;
  	/*
  	 * rcu_dereference_raw protected by se_lun->lun_group symlink
  	 * reference to se_device->dev_group.
  	 */
  	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
  
  	if (!nacl)
  		return -EINVAL;
  
  	if (lun->lun_access_ro)
  		lun_access_ro = true;
  
  	lacl->se_lun = lun;
  
  	if (core_enable_device_list_for_node(lun, lacl, lacl->mapped_lun,
  			lun_access_ro, nacl, tpg) < 0)
  		return -EINVAL;
  
  	pr_debug("%s_TPG[%hu]_LUN[%llu->%llu] - Added %s ACL for "
  		" InitiatorNode: %s\n", tpg->se_tpg_tfo->fabric_name,
  		tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun, lacl->mapped_lun,
  		lun_access_ro ? "RO" : "RW",
  		nacl->initiatorname);
  	/*
  	 * Check to see if there are any existing persistent reservation APTPL
  	 * pre-registrations that need to be enabled for this LUN ACL..
  	 */
  	core_scsi3_check_aptpl_registration(dev, tpg, lun, nacl,
  					    lacl->mapped_lun);
  	return 0;
  }
  
  int core_dev_del_initiator_node_lun_acl(
  	struct se_lun *lun,
  	struct se_lun_acl *lacl)
  {
  	struct se_portal_group *tpg = lun->lun_tpg;
  	struct se_node_acl *nacl;
  	struct se_dev_entry *deve;
  
  	nacl = lacl->se_lun_nacl;
  	if (!nacl)
  		return -EINVAL;
  
  	mutex_lock(&nacl->lun_entry_mutex);
  	deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
  	if (deve)
  		core_disable_device_list_for_node(lun, deve, nacl, tpg);
  	mutex_unlock(&nacl->lun_entry_mutex);
  
  	pr_debug("%s_TPG[%hu]_LUN[%llu] - Removed ACL for"
  		" InitiatorNode: %s Mapped LUN: %llu\n",
  		tpg->se_tpg_tfo->fabric_name,
  		tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
  		nacl->initiatorname, lacl->mapped_lun);
  
  	return 0;
  }
  
  void core_dev_free_initiator_node_lun_acl(
  	struct se_portal_group *tpg,
  	struct se_lun_acl *lacl)
  {
  	pr_debug("%s_TPG[%hu] - Freeing ACL for %s InitiatorNode: %s"
  		" Mapped LUN: %llu\n", tpg->se_tpg_tfo->fabric_name,
  		tpg->se_tpg_tfo->tpg_get_tag(tpg),
  		tpg->se_tpg_tfo->fabric_name,
  		lacl->se_lun_nacl->initiatorname, lacl->mapped_lun);
  
  	kfree(lacl);
  }
  
  static void scsi_dump_inquiry(struct se_device *dev)
  {
  	struct t10_wwn *wwn = &dev->t10_wwn;
  	int device_type = dev->transport->get_device_type(dev);
  
  	/*
  	 * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
  	 */
  	pr_debug("  Vendor: %-" __stringify(INQUIRY_VENDOR_LEN) "s\n",
  		wwn->vendor);
  	pr_debug("  Model: %-" __stringify(INQUIRY_MODEL_LEN) "s\n",
  		wwn->model);
  	pr_debug("  Revision: %-" __stringify(INQUIRY_REVISION_LEN) "s\n",
  		wwn->revision);
  	pr_debug("  Type:   %s ", scsi_device_type(device_type));
  }
  
  struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
  {
  	struct se_device *dev;
  	struct se_lun *xcopy_lun;
  	int i;
  
  	dev = hba->backend->ops->alloc_device(hba, name);
  	if (!dev)
  		return NULL;
  
  	dev->queues = kcalloc(nr_cpu_ids, sizeof(*dev->queues), GFP_KERNEL);
  	if (!dev->queues) {
  		dev->transport->free_device(dev);
  		return NULL;
  	}
  
  	dev->queue_cnt = nr_cpu_ids;
  	for (i = 0; i < dev->queue_cnt; i++) {
  		struct se_device_queue *q;
  
  		q = &dev->queues[i];
  		INIT_LIST_HEAD(&q->state_list);
  		spin_lock_init(&q->lock);
  
  		init_llist_head(&q->sq.cmd_list);
  		INIT_WORK(&q->sq.work, target_queued_submit_work);
  	}
  
  	dev->se_hba = hba;
  	dev->transport = hba->backend->ops;
  	dev->transport_flags = dev->transport->transport_flags_default;
  	dev->prot_length = sizeof(struct t10_pi_tuple);
  	dev->hba_index = hba->hba_index;
  
  	INIT_LIST_HEAD(&dev->dev_sep_list);
  	INIT_LIST_HEAD(&dev->dev_tmr_list);
  	INIT_LIST_HEAD(&dev->delayed_cmd_list);
  	INIT_LIST_HEAD(&dev->qf_cmd_list);
  	spin_lock_init(&dev->delayed_cmd_lock);
  	spin_lock_init(&dev->dev_reservation_lock);
  	spin_lock_init(&dev->se_port_lock);
  	spin_lock_init(&dev->se_tmr_lock);
  	spin_lock_init(&dev->qf_cmd_lock);
  	sema_init(&dev->caw_sem, 1);
  	INIT_LIST_HEAD(&dev->t10_wwn.t10_vpd_list);
  	spin_lock_init(&dev->t10_wwn.t10_vpd_lock);
  	INIT_LIST_HEAD(&dev->t10_pr.registration_list);
  	INIT_LIST_HEAD(&dev->t10_pr.aptpl_reg_list);
  	spin_lock_init(&dev->t10_pr.registration_lock);
  	spin_lock_init(&dev->t10_pr.aptpl_reg_lock);
  	INIT_LIST_HEAD(&dev->t10_alua.tg_pt_gps_list);
  	spin_lock_init(&dev->t10_alua.tg_pt_gps_lock);
  	INIT_LIST_HEAD(&dev->t10_alua.lba_map_list);
  	spin_lock_init(&dev->t10_alua.lba_map_lock);
  
  	INIT_WORK(&dev->delayed_cmd_work, target_do_delayed_work);
  
  	dev->t10_wwn.t10_dev = dev;
  	/*
  	 * Use OpenFabrics IEEE Company ID: 00 14 05
  	 */
  	dev->t10_wwn.company_id = 0x001405;
  
  	dev->t10_alua.t10_dev = dev;
  
  	dev->dev_attrib.da_dev = dev;
  	dev->dev_attrib.emulate_model_alias = DA_EMULATE_MODEL_ALIAS;
  	dev->dev_attrib.emulate_dpo = 1;
  	dev->dev_attrib.emulate_fua_write = 1;
  	dev->dev_attrib.emulate_fua_read = 1;
  	dev->dev_attrib.emulate_write_cache = DA_EMULATE_WRITE_CACHE;
  	dev->dev_attrib.emulate_ua_intlck_ctrl = TARGET_UA_INTLCK_CTRL_CLEAR;
  	dev->dev_attrib.emulate_tas = DA_EMULATE_TAS;
  	dev->dev_attrib.emulate_tpu = DA_EMULATE_TPU;
  	dev->dev_attrib.emulate_tpws = DA_EMULATE_TPWS;
  	dev->dev_attrib.emulate_caw = DA_EMULATE_CAW;
  	dev->dev_attrib.emulate_3pc = DA_EMULATE_3PC;
  	dev->dev_attrib.emulate_pr = DA_EMULATE_PR;
  	dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE0_PROT;
  	dev->dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS;
  	dev->dev_attrib.force_pr_aptpl = DA_FORCE_PR_APTPL;
  	dev->dev_attrib.is_nonrot = DA_IS_NONROT;
  	dev->dev_attrib.emulate_rest_reord = DA_EMULATE_REST_REORD;
  	dev->dev_attrib.max_unmap_lba_count = DA_MAX_UNMAP_LBA_COUNT;
  	dev->dev_attrib.max_unmap_block_desc_count =
  		DA_MAX_UNMAP_BLOCK_DESC_COUNT;
  	dev->dev_attrib.unmap_granularity = DA_UNMAP_GRANULARITY_DEFAULT;
  	dev->dev_attrib.unmap_granularity_alignment =
  				DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT;
  	dev->dev_attrib.unmap_zeroes_data =
  				DA_UNMAP_ZEROES_DATA_DEFAULT;
  	dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN;
  
  	xcopy_lun = &dev->xcopy_lun;
  	rcu_assign_pointer(xcopy_lun->lun_se_dev, dev);
  	init_completion(&xcopy_lun->lun_shutdown_comp);
  	INIT_LIST_HEAD(&xcopy_lun->lun_deve_list);
  	INIT_LIST_HEAD(&xcopy_lun->lun_dev_link);
  	mutex_init(&xcopy_lun->lun_tg_pt_md_mutex);
  	xcopy_lun->lun_tpg = &xcopy_pt_tpg;
  
  	/* Preload the default INQUIRY const values */
  	strlcpy(dev->t10_wwn.vendor, "LIO-ORG", sizeof(dev->t10_wwn.vendor));
  	strlcpy(dev->t10_wwn.model, dev->transport->inquiry_prod,
  		sizeof(dev->t10_wwn.model));
  	strlcpy(dev->t10_wwn.revision, dev->transport->inquiry_rev,
  		sizeof(dev->t10_wwn.revision));
  
  	return dev;
  }
  
  /*
   * Check if the underlying struct block_device request_queue supports
   * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
   * in ATA and we need to set TPE=1
   */
  bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
  				       struct request_queue *q)
  {
  	int block_size = queue_logical_block_size(q);
  
  	if (!blk_queue_discard(q))
  		return false;
  
  	attrib->max_unmap_lba_count =
  		q->limits.max_discard_sectors >> (ilog2(block_size) - 9);
  	/*
  	 * Currently hardcoded to 1 in Linux/SCSI code..
  	 */
  	attrib->max_unmap_block_desc_count = 1;
  	attrib->unmap_granularity = q->limits.discard_granularity / block_size;
  	attrib->unmap_granularity_alignment = q->limits.discard_alignment /
  								block_size;
  	attrib->unmap_zeroes_data = !!(q->limits.max_write_zeroes_sectors);
  	return true;
  }
  EXPORT_SYMBOL(target_configure_unmap_from_queue);
  
  /*
   * Convert from blocksize advertised to the initiator to the 512 byte
   * units unconditionally used by the Linux block layer.
   */
  sector_t target_to_linux_sector(struct se_device *dev, sector_t lb)
  {
  	switch (dev->dev_attrib.block_size) {
  	case 4096:
  		return lb << 3;
  	case 2048:
  		return lb << 2;
  	case 1024:
  		return lb << 1;
  	default:
  		return lb;
  	}
  }
  EXPORT_SYMBOL(target_to_linux_sector);
  
  struct devices_idr_iter {
  	struct config_item *prev_item;
  	int (*fn)(struct se_device *dev, void *data);
  	void *data;
  };
  
  static int target_devices_idr_iter(int id, void *p, void *data)
  	 __must_hold(&device_mutex)
  {
  	struct devices_idr_iter *iter = data;
  	struct se_device *dev = p;
  	int ret;
  
  	config_item_put(iter->prev_item);
  	iter->prev_item = NULL;
  
  	/*
  	 * We add the device early to the idr, so it can be used
  	 * by backend modules during configuration. We do not want
  	 * to allow other callers to access partially setup devices,
  	 * so we skip them here.
  	 */
  	if (!target_dev_configured(dev))
  		return 0;
  
  	iter->prev_item = config_item_get_unless_zero(&dev->dev_group.cg_item);
  	if (!iter->prev_item)
  		return 0;
  	mutex_unlock(&device_mutex);
  
  	ret = iter->fn(dev, iter->data);
  
  	mutex_lock(&device_mutex);
  	return ret;
  }
  
  /**
   * target_for_each_device - iterate over configured devices
   * @fn: iterator function
   * @data: pointer to data that will be passed to fn
   *
   * fn must return 0 to continue looping over devices. non-zero will break
   * from the loop and return that value to the caller.
   */
  int target_for_each_device(int (*fn)(struct se_device *dev, void *data),
  			   void *data)
  {
  	struct devices_idr_iter iter = { .fn = fn, .data = data };
  	int ret;
  
  	mutex_lock(&device_mutex);
  	ret = idr_for_each(&devices_idr, target_devices_idr_iter, &iter);
  	mutex_unlock(&device_mutex);
  	config_item_put(iter.prev_item);
  	return ret;
  }
  
  int target_configure_device(struct se_device *dev)
  {
  	struct se_hba *hba = dev->se_hba;
  	int ret, id;
  
  	if (target_dev_configured(dev)) {
  		pr_err("se_dev->se_dev_ptr already set for storage"
  				" object\n");
  		return -EEXIST;
  	}
  
  	/*
  	 * Add early so modules like tcmu can use during its
  	 * configuration.
  	 */
  	mutex_lock(&device_mutex);
  	/*
  	 * Use cyclic to try and avoid collisions with devices
  	 * that were recently removed.
  	 */
  	id = idr_alloc_cyclic(&devices_idr, dev, 0, INT_MAX, GFP_KERNEL);
  	mutex_unlock(&device_mutex);
  	if (id < 0) {
  		ret = -ENOMEM;
  		goto out;
  	}
  	dev->dev_index = id;
  
  	ret = dev->transport->configure_device(dev);
  	if (ret)
  		goto out_free_index;
  	/*
  	 * XXX: there is not much point to have two different values here..
  	 */
  	dev->dev_attrib.block_size = dev->dev_attrib.hw_block_size;
  	dev->dev_attrib.queue_depth = dev->dev_attrib.hw_queue_depth;
  
  	/*
  	 * Align max_hw_sectors down to PAGE_SIZE I/O transfers
  	 */
  	dev->dev_attrib.hw_max_sectors =
  		se_dev_align_max_sectors(dev->dev_attrib.hw_max_sectors,
  					 dev->dev_attrib.hw_block_size);
  	dev->dev_attrib.optimal_sectors = dev->dev_attrib.hw_max_sectors;
  
  	dev->creation_time = get_jiffies_64();
  
  	ret = core_setup_alua(dev);
  	if (ret)
  		goto out_destroy_device;
  
  	/*
  	 * Setup work_queue for QUEUE_FULL
  	 */
  	INIT_WORK(&dev->qf_work_queue, target_qf_do_work);
  
  	scsi_dump_inquiry(dev);
  
  	spin_lock(&hba->device_lock);
  	hba->dev_count++;
  	spin_unlock(&hba->device_lock);
  
  	dev->dev_flags |= DF_CONFIGURED;
  
  	return 0;
  
  out_destroy_device:
  	dev->transport->destroy_device(dev);
  out_free_index:
  	mutex_lock(&device_mutex);
  	idr_remove(&devices_idr, dev->dev_index);
  	mutex_unlock(&device_mutex);
  out:
  	se_release_vpd_for_dev(dev);
  	return ret;
  }
  
  void target_free_device(struct se_device *dev)
  {
  	struct se_hba *hba = dev->se_hba;
  
  	WARN_ON(!list_empty(&dev->dev_sep_list));
  
  	if (target_dev_configured(dev)) {
  		dev->transport->destroy_device(dev);
  
  		mutex_lock(&device_mutex);
  		idr_remove(&devices_idr, dev->dev_index);
  		mutex_unlock(&device_mutex);
  
  		spin_lock(&hba->device_lock);
  		hba->dev_count--;
  		spin_unlock(&hba->device_lock);
  	}
  
  	core_alua_free_lu_gp_mem(dev);
  	core_alua_set_lba_map(dev, NULL, 0, 0);
  	core_scsi3_free_all_registrations(dev);
  	se_release_vpd_for_dev(dev);
  
  	if (dev->transport->free_prot)
  		dev->transport->free_prot(dev);
  
  	kfree(dev->queues);
  	dev->transport->free_device(dev);
  }
  
  int core_dev_setup_virtual_lun0(void)
  {
  	struct se_hba *hba;
  	struct se_device *dev;
  	char buf[] = "rd_pages=8,rd_nullio=1,rd_dummy=1";
  	int ret;
  
  	hba = core_alloc_hba("rd_mcp", 0, HBA_FLAGS_INTERNAL_USE);
  	if (IS_ERR(hba))
  		return PTR_ERR(hba);
  
  	dev = target_alloc_device(hba, "virt_lun0");
  	if (!dev) {
  		ret = -ENOMEM;
  		goto out_free_hba;
  	}
  
  	hba->backend->ops->set_configfs_dev_params(dev, buf, sizeof(buf));
  
  	ret = target_configure_device(dev);
  	if (ret)
  		goto out_free_se_dev;
  
  	lun0_hba = hba;
  	g_lun0_dev = dev;
  	return 0;
  
  out_free_se_dev:
  	target_free_device(dev);
  out_free_hba:
  	core_delete_hba(hba);
  	return ret;
  }
  
  
  void core_dev_release_virtual_lun0(void)
  {
  	struct se_hba *hba = lun0_hba;
  
  	if (!hba)
  		return;
  
  	if (g_lun0_dev)
  		target_free_device(g_lun0_dev);
  	core_delete_hba(hba);
  }
  
  /*
   * Common CDB parsing for kernel and user passthrough.
   */
  sense_reason_t
  passthrough_parse_cdb(struct se_cmd *cmd,
  	sense_reason_t (*exec_cmd)(struct se_cmd *cmd))
  {
  	unsigned char *cdb = cmd->t_task_cdb;
  	struct se_device *dev = cmd->se_dev;
  	unsigned int size;
  
  	/*
  	 * For REPORT LUNS we always need to emulate the response, for everything
  	 * else, pass it up.
  	 */
  	if (cdb[0] == REPORT_LUNS) {
  		cmd->execute_cmd = spc_emulate_report_luns;
  		return TCM_NO_SENSE;
  	}
  
  	/*
  	 * With emulate_pr disabled, all reservation requests should fail,
  	 * regardless of whether or not TRANSPORT_FLAG_PASSTHROUGH_PGR is set.
  	 */
  	if (!dev->dev_attrib.emulate_pr &&
  	    ((cdb[0] == PERSISTENT_RESERVE_IN) ||
  	     (cdb[0] == PERSISTENT_RESERVE_OUT) ||
  	     (cdb[0] == RELEASE || cdb[0] == RELEASE_10) ||
  	     (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) {
  		return TCM_UNSUPPORTED_SCSI_OPCODE;
  	}
  
  	/*
  	 * For PERSISTENT RESERVE IN/OUT, RELEASE, and RESERVE we need to
  	 * emulate the response, since tcmu does not have the information
  	 * required to process these commands.
  	 */
  	if (!(dev->transport_flags &
  	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
  		if (cdb[0] == PERSISTENT_RESERVE_IN) {
  			cmd->execute_cmd = target_scsi3_emulate_pr_in;
  			size = get_unaligned_be16(&cdb[7]);
  			return target_cmd_size_check(cmd, size);
  		}
  		if (cdb[0] == PERSISTENT_RESERVE_OUT) {
  			cmd->execute_cmd = target_scsi3_emulate_pr_out;
  			size = get_unaligned_be32(&cdb[5]);
  			return target_cmd_size_check(cmd, size);
  		}
  
  		if (cdb[0] == RELEASE || cdb[0] == RELEASE_10) {
  			cmd->execute_cmd = target_scsi2_reservation_release;
  			if (cdb[0] == RELEASE_10)
  				size = get_unaligned_be16(&cdb[7]);
  			else
  				size = cmd->data_length;
  			return target_cmd_size_check(cmd, size);
  		}
  		if (cdb[0] == RESERVE || cdb[0] == RESERVE_10) {
  			cmd->execute_cmd = target_scsi2_reservation_reserve;
  			if (cdb[0] == RESERVE_10)
  				size = get_unaligned_be16(&cdb[7]);
  			else
  				size = cmd->data_length;
  			return target_cmd_size_check(cmd, size);
  		}
  	}
  
  	/* Set DATA_CDB flag for ops that should have it */
  	switch (cdb[0]) {
  	case READ_6:
  	case READ_10:
  	case READ_12:
  	case READ_16:
  	case WRITE_6:
  	case WRITE_10:
  	case WRITE_12:
  	case WRITE_16:
  	case WRITE_VERIFY:
  	case WRITE_VERIFY_12:
  	case WRITE_VERIFY_16:
  	case COMPARE_AND_WRITE:
  	case XDWRITEREAD_10:
  		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
  		break;
  	case VARIABLE_LENGTH_CMD:
  		switch (get_unaligned_be16(&cdb[8])) {
  		case READ_32:
  		case WRITE_32:
  		case WRITE_VERIFY_32:
  		case XDWRITEREAD_32:
  			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
  			break;
  		}
  	}
  
  	cmd->execute_cmd = exec_cmd;
  
  	return TCM_NO_SENSE;
  }
  EXPORT_SYMBOL(passthrough_parse_cdb);
  