blob: e3f7e21e661413db88360599c70382a92a4d8632 [file] [log] [blame]
/*******************************************************************************
* Filename: target_core_transport.c
*
* This file contains the Generic Target Engine Core.
*
* (c) Copyright 2002-2013 Datera, Inc.
*
* Nicholas A. Bellinger <nab@kernel.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
******************************************************************************/
#include <linux/net.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/in.h>
#include <linux/cdrom.h>
#include <linux/module.h>
#include <linux/ratelimit.h>
#include <linux/vmalloc.h>
#include <asm/unaligned.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <scsi/scsi_proto.h>
#include <scsi/scsi_common.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"
#define CREATE_TRACE_POINTS
#include <trace/events/target.h>
static struct workqueue_struct *target_completion_wq;
static struct kmem_cache *se_sess_cache;
struct kmem_cache *se_ua_cache;
struct kmem_cache *t10_pr_reg_cache;
struct kmem_cache *t10_alua_lu_gp_cache;
struct kmem_cache *t10_alua_lu_gp_mem_cache;
struct kmem_cache *t10_alua_tg_pt_gp_cache;
struct kmem_cache *t10_alua_lba_map_cache;
struct kmem_cache *t10_alua_lba_map_mem_cache;
static void transport_complete_task_attr(struct se_cmd *cmd);
static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
static void transport_handle_queue_full(struct se_cmd *cmd,
struct se_device *dev, int err, bool write_pending);
static void target_complete_ok_work(struct work_struct *work);
int init_se_kmem_caches(void)
{
se_sess_cache = kmem_cache_create("se_sess_cache",
sizeof(struct se_session), __alignof__(struct se_session),
0, NULL);
if (!se_sess_cache) {
pr_err("kmem_cache_create() for struct se_session"
" failed\n");
goto out;
}
se_ua_cache = kmem_cache_create("se_ua_cache",
sizeof(struct se_ua), __alignof__(struct se_ua),
0, NULL);
if (!se_ua_cache) {
pr_err("kmem_cache_create() for struct se_ua failed\n");
goto out_free_sess_cache;
}
t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
sizeof(struct t10_pr_registration),
__alignof__(struct t10_pr_registration), 0, NULL);
if (!t10_pr_reg_cache) {
pr_err("kmem_cache_create() for struct t10_pr_registration"
" failed\n");
goto out_free_ua_cache;
}
t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
0, NULL);
if (!t10_alua_lu_gp_cache) {
pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
" failed\n");
goto out_free_pr_reg_cache;
}
t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
sizeof(struct t10_alua_lu_gp_member),
__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
if (!t10_alua_lu_gp_mem_cache) {
pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
"cache failed\n");
goto out_free_lu_gp_cache;
}
t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
sizeof(struct t10_alua_tg_pt_gp),
__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
if (!t10_alua_tg_pt_gp_cache) {
pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
"cache failed\n");
goto out_free_lu_gp_mem_cache;
}
t10_alua_lba_map_cache = kmem_cache_create(
"t10_alua_lba_map_cache",
sizeof(struct t10_alua_lba_map),
__alignof__(struct t10_alua_lba_map), 0, NULL);
if (!t10_alua_lba_map_cache) {
pr_err("kmem_cache_create() for t10_alua_lba_map_"
"cache failed\n");
goto out_free_tg_pt_gp_cache;
}
t10_alua_lba_map_mem_cache = kmem_cache_create(
"t10_alua_lba_map_mem_cache",
sizeof(struct t10_alua_lba_map_member),
__alignof__(struct t10_alua_lba_map_member), 0, NULL);
if (!t10_alua_lba_map_mem_cache) {
pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
"cache failed\n");
goto out_free_lba_map_cache;
}
target_completion_wq = alloc_workqueue("target_completion",
WQ_MEM_RECLAIM, 0);
if (!target_completion_wq)
goto out_free_lba_map_mem_cache;
return 0;
out_free_lba_map_mem_cache:
kmem_cache_destroy(t10_alua_lba_map_mem_cache);
out_free_lba_map_cache:
kmem_cache_destroy(t10_alua_lba_map_cache);
out_free_tg_pt_gp_cache:
kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
out_free_lu_gp_mem_cache:
kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
out_free_lu_gp_cache:
kmem_cache_destroy(t10_alua_lu_gp_cache);
out_free_pr_reg_cache:
kmem_cache_destroy(t10_pr_reg_cache);
out_free_ua_cache:
kmem_cache_destroy(se_ua_cache);
out_free_sess_cache:
kmem_cache_destroy(se_sess_cache);
out:
return -ENOMEM;
}
void release_se_kmem_caches(void)
{
destroy_workqueue(target_completion_wq);
kmem_cache_destroy(se_sess_cache);
kmem_cache_destroy(se_ua_cache);
kmem_cache_destroy(t10_pr_reg_cache);
kmem_cache_destroy(t10_alua_lu_gp_cache);
kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
kmem_cache_destroy(t10_alua_lba_map_cache);
kmem_cache_destroy(t10_alua_lba_map_mem_cache);
}
/* This code ensures unique mib indexes are handed out. */
static DEFINE_SPINLOCK(scsi_mib_index_lock);
static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
/*
* Allocate a new row index for the entry type specified
*/
u32 scsi_get_new_index(scsi_index_t type)
{
u32 new_index;
BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
spin_lock(&scsi_mib_index_lock);
new_index = ++scsi_mib_index[type];
spin_unlock(&scsi_mib_index_lock);
return new_index;
}
void transport_subsystem_check_init(void)
{
int ret;
static int sub_api_initialized;
if (sub_api_initialized)
return;
ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
if (ret != 0)
pr_err("Unable to load target_core_iblock\n");
ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
if (ret != 0)
pr_err("Unable to load target_core_file\n");
ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
if (ret != 0)
pr_err("Unable to load target_core_pscsi\n");
ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
if (ret != 0)
pr_err("Unable to load target_core_user\n");
sub_api_initialized = 1;
}
static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
{
struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
wake_up(&sess->cmd_list_wq);
}
/**
* transport_init_session - initialize a session object
* @se_sess: Session object pointer.
*
* The caller must have zero-initialized @se_sess before calling this function.
*/
int transport_init_session(struct se_session *se_sess)
{
INIT_LIST_HEAD(&se_sess->sess_list);
INIT_LIST_HEAD(&se_sess->sess_acl_list);
INIT_LIST_HEAD(&se_sess->sess_cmd_list);
spin_lock_init(&se_sess->sess_cmd_lock);
init_waitqueue_head(&se_sess->cmd_list_wq);
return percpu_ref_init(&se_sess->cmd_count,
target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
}
EXPORT_SYMBOL(transport_init_session);
/**
* transport_alloc_session - allocate a session object and initialize it
* @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
*/
struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
{
struct se_session *se_sess;
int ret;
se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
if (!se_sess) {
pr_err("Unable to allocate struct se_session from"
" se_sess_cache\n");
return ERR_PTR(-ENOMEM);
}
ret = transport_init_session(se_sess);
if (ret < 0) {
kmem_cache_free(se_sess_cache, se_sess);
return ERR_PTR(ret);
}
se_sess->sup_prot_ops = sup_prot_ops;
return se_sess;
}
EXPORT_SYMBOL(transport_alloc_session);
/**
* transport_alloc_session_tags - allocate target driver private data
* @se_sess: Session pointer.
* @tag_num: Maximum number of in-flight commands between initiator and target.
* @tag_size: Size in bytes of the private data a target driver associates with
* each command.
*/
int transport_alloc_session_tags(struct se_session *se_sess,
unsigned int tag_num, unsigned int tag_size)
{
int rc;
se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!se_sess->sess_cmd_map) {
pr_err("Unable to allocate se_sess->sess_cmd_map\n");
return -ENOMEM;
}
rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
false, GFP_KERNEL, NUMA_NO_NODE);
if (rc < 0) {
pr_err("Unable to init se_sess->sess_tag_pool,"
" tag_num: %u\n", tag_num);
kvfree(se_sess->sess_cmd_map);
se_sess->sess_cmd_map = NULL;
return -ENOMEM;
}
return 0;
}
EXPORT_SYMBOL(transport_alloc_session_tags);
/**
* transport_init_session_tags - allocate a session and target driver private data
* @tag_num: Maximum number of in-flight commands between initiator and target.
* @tag_size: Size in bytes of the private data a target driver associates with
* each command.
* @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
*/
static struct se_session *
transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
enum target_prot_op sup_prot_ops)
{
struct se_session *se_sess;
int rc;
if (tag_num != 0 && !tag_size) {
pr_err("init_session_tags called with percpu-ida tag_num:"
" %u, but zero tag_size\n", tag_num);
return ERR_PTR(-EINVAL);
}
if (!tag_num && tag_size) {
pr_err("init_session_tags called with percpu-ida tag_size:"
" %u, but zero tag_num\n", tag_size);
return ERR_PTR(-EINVAL);
}
se_sess = transport_alloc_session(sup_prot_ops);
if (IS_ERR(se_sess))
return se_sess;
rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
if (rc < 0) {
transport_free_session(se_sess);
return ERR_PTR(-ENOMEM);
}
return se_sess;
}
/*
* Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
*/
void __transport_register_session(
struct se_portal_group *se_tpg,
struct se_node_acl *se_nacl,
struct se_session *se_sess,
void *fabric_sess_ptr)
{
const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
unsigned char buf[PR_REG_ISID_LEN];
unsigned long flags;
se_sess->se_tpg = se_tpg;
se_sess->fabric_sess_ptr = fabric_sess_ptr;
/*
* Used by struct se_node_acl's under ConfigFS to locate active se_session-t
*
* Only set for struct se_session's that will actually be moving I/O.
* eg: *NOT* discovery sessions.
*/
if (se_nacl) {
/*
*
* Determine if fabric allows for T10-PI feature bits exposed to
* initiators for device backends with !dev->dev_attrib.pi_prot_type.
*
* If so, then always save prot_type on a per se_node_acl node
* basis and re-instate the previous sess_prot_type to avoid
* disabling PI from below any previously initiator side
* registered LUNs.
*/
if (se_nacl->saved_prot_type)
se_sess->sess_prot_type = se_nacl->saved_prot_type;
else if (tfo->tpg_check_prot_fabric_only)
se_sess->sess_prot_type = se_nacl->saved_prot_type =
tfo->tpg_check_prot_fabric_only(se_tpg);
/*
* If the fabric module supports an ISID based TransportID,
* save this value in binary from the fabric I_T Nexus now.
*/
if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
memset(&buf[0], 0, PR_REG_ISID_LEN);
se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
&buf[0], PR_REG_ISID_LEN);
se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
}
spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
/*
* The se_nacl->nacl_sess pointer will be set to the
* last active I_T Nexus for each struct se_node_acl.
*/
se_nacl->nacl_sess = se_sess;
list_add_tail(&se_sess->sess_acl_list,
&se_nacl->acl_sess_list);
spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
}
list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
}
EXPORT_SYMBOL(__transport_register_session);
void transport_register_session(
struct se_portal_group *se_tpg,
struct se_node_acl *se_nacl,
struct se_session *se_sess,
void *fabric_sess_ptr)
{
unsigned long flags;
spin_lock_irqsave(&se_tpg->session_lock, flags);
__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
spin_unlock_irqrestore(&se_tpg->session_lock, flags);
}
EXPORT_SYMBOL(transport_register_session);
struct se_session *
target_setup_session(struct se_portal_group *tpg,
unsigned int tag_num, unsigned int tag_size,
enum target_prot_op prot_op,
const char *initiatorname, void *private,
int (*callback)(struct se_portal_group *,
struct se_session *, void *))
{
struct se_session *sess;
/*
* If the fabric driver is using percpu-ida based pre allocation
* of I/O descriptor tags, go ahead and perform that setup now..
*/
if (tag_num != 0)
sess = transport_init_session_tags(tag_num, tag_size, prot_op);
else
sess = transport_alloc_session(prot_op);
if (IS_ERR(sess))
return sess;
sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
(unsigned char *)initiatorname);
if (!sess->se_node_acl) {
transport_free_session(sess);
return ERR_PTR(-EACCES);
}
/*
* Go ahead and perform any remaining fabric setup that is
* required before transport_register_session().
*/
if (callback != NULL) {
int rc = callback(tpg, sess, private);
if (rc) {
transport_free_session(sess);
return ERR_PTR(rc);
}
}
transport_register_session(tpg, sess->se_node_acl, sess, private);
return sess;
}
EXPORT_SYMBOL(target_setup_session);
ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
{
struct se_session *se_sess;
ssize_t len = 0;
spin_lock_bh(&se_tpg->session_lock);
list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
if (!se_sess->se_node_acl)
continue;
if (!se_sess->se_node_acl->dynamic_node_acl)
continue;
if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
break;
len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
se_sess->se_node_acl->initiatorname);
len += 1; /* Include NULL terminator */
}
spin_unlock_bh(&se_tpg->session_lock);
return len;
}
EXPORT_SYMBOL(target_show_dynamic_sessions);
static void target_complete_nacl(struct kref *kref)
{
struct se_node_acl *nacl = container_of(kref,
struct se_node_acl, acl_kref);
struct se_portal_group *se_tpg = nacl->se_tpg;
if (!nacl->dynamic_stop) {
complete(&nacl->acl_free_comp);
return;
}
mutex_lock(&se_tpg->acl_node_mutex);
list_del_init(&nacl->acl_list);
mutex_unlock(&se_tpg->acl_node_mutex);
core_tpg_wait_for_nacl_pr_ref(nacl);
core_free_device_list_for_node(nacl, se_tpg);
kfree(nacl);
}
void target_put_nacl(struct se_node_acl *nacl)
{
kref_put(&nacl->acl_kref, target_complete_nacl);
}
EXPORT_SYMBOL(target_put_nacl);
void transport_deregister_session_configfs(struct se_session *se_sess)
{
struct se_node_acl *se_nacl;
unsigned long flags;
/*
* Used by struct se_node_acl's under ConfigFS to locate active struct se_session
*/
se_nacl = se_sess->se_node_acl;
if (se_nacl) {
spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
if (!list_empty(&se_sess->sess_acl_list))
list_del_init(&se_sess->sess_acl_list);
/*
* If the session list is empty, then clear the pointer.
* Otherwise, set the struct se_session pointer from the tail
* element of the per struct se_node_acl active session list.
*/
if (list_empty(&se_nacl->acl_sess_list))
se_nacl->nacl_sess = NULL;
else {
se_nacl->nacl_sess = container_of(
se_nacl->acl_sess_list.prev,
struct se_session, sess_acl_list);
}
spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
}
}
EXPORT_SYMBOL(transport_deregister_session_configfs);
void transport_free_session(struct se_session *se_sess)
{
struct se_node_acl *se_nacl = se_sess->se_node_acl;
/*
* Drop the se_node_acl->nacl_kref obtained from within
* core_tpg_get_initiator_node_acl().
*/
if (se_nacl) {
struct se_portal_group *se_tpg = se_nacl->se_tpg;
const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
unsigned long flags;
se_sess->se_node_acl = NULL;
/*
* Also determine if we need to drop the extra ->cmd_kref if
* it had been previously dynamically generated, and
* the endpoint is not caching dynamic ACLs.
*/
mutex_lock(&se_tpg->acl_node_mutex);
if (se_nacl->dynamic_node_acl &&
!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
if (list_empty(&se_nacl->acl_sess_list))
se_nacl->dynamic_stop = true;
spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
if (se_nacl->dynamic_stop)
list_del_init(&se_nacl->acl_list);
}
mutex_unlock(&se_tpg->acl_node_mutex);
if (se_nacl->dynamic_stop)
target_put_nacl(se_nacl);
target_put_nacl(se_nacl);
}
if (se_sess->sess_cmd_map) {
sbitmap_queue_free(&se_sess->sess_tag_pool);
kvfree(se_sess->sess_cmd_map);
}
percpu_ref_exit(&se_sess->cmd_count);
kmem_cache_free(se_sess_cache, se_sess);
}
EXPORT_SYMBOL(transport_free_session);
void transport_deregister_session(struct se_session *se_sess)
{
struct se_portal_group *se_tpg = se_sess->se_tpg;
unsigned long flags;
if (!se_tpg) {
transport_free_session(se_sess);
return;
}
spin_lock_irqsave(&se_tpg->session_lock, flags);
list_del(&se_sess->sess_list);
se_sess->se_tpg = NULL;
se_sess->fabric_sess_ptr = NULL;
spin_unlock_irqrestore(&se_tpg->session_lock, flags);
pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
se_tpg->se_tpg_tfo->fabric_name);
/*
* If last kref is dropping now for an explicit NodeACL, awake sleeping
* ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
* removal context from within transport_free_session() code.
*
* For dynamic ACL, target_put_nacl() uses target_complete_nacl()
* to release all remaining generate_node_acl=1 created ACL resources.
*/
transport_free_session(se_sess);
}
EXPORT_SYMBOL(transport_deregister_session);
void target_remove_session(struct se_session *se_sess)
{
transport_deregister_session_configfs(se_sess);
transport_deregister_session(se_sess);
}
EXPORT_SYMBOL(target_remove_session);
static void target_remove_from_state_list(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned long flags;
if (!dev)
return;
spin_lock_irqsave(&dev->execute_task_lock, flags);
if (cmd->state_active) {
list_del(&cmd->state_list);
cmd->state_active = false;
}
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
/*
* This function is called by the target core after the target core has
* finished processing a SCSI command or SCSI TMF. Both the regular command
* processing code and the code for aborting commands can call this
* function. CMD_T_STOP is set if and only if another thread is waiting
* inside transport_wait_for_tasks() for t_transport_stop_comp.
*/
static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
{
unsigned long flags;
target_remove_from_state_list(cmd);
spin_lock_irqsave(&cmd->t_state_lock, flags);
/*
* Determine if frontend context caller is requesting the stopping of
* this command for frontend exceptions.
*/
if (cmd->transport_state & CMD_T_STOP) {
pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
__func__, __LINE__, cmd->tag);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete_all(&cmd->t_transport_stop_comp);
return 1;
}
cmd->transport_state &= ~CMD_T_ACTIVE;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
/*
* Some fabric modules like tcm_loop can release their internally
* allocated I/O reference and struct se_cmd now.
*
* Fabric modules are expected to return '1' here if the se_cmd being
* passed is released at this point, or zero if not being released.
*/
return cmd->se_tfo->check_stop_free(cmd);
}
static void target_complete_failure_work(struct work_struct *work)
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
transport_generic_request_failure(cmd,
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
}
/*
* Used when asking transport to copy Sense Data from the underlying
* Linux/SCSI struct scsi_cmnd
*/
static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
WARN_ON(!cmd->se_lun);
if (!dev)
return NULL;
if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
return NULL;
cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
return cmd->sense_buffer;
}
void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
{
unsigned char *cmd_sense_buf;
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
cmd_sense_buf = transport_get_sense_buffer(cmd);
if (!cmd_sense_buf) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return;
}
cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
EXPORT_SYMBOL(transport_copy_sense_to_cmd);
static void target_handle_abort(struct se_cmd *cmd)
{
bool tas = cmd->transport_state & CMD_T_TAS;
bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
int ret;
pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
if (tas) {
if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
cmd->scsi_status = SAM_STAT_TASK_ABORTED;
pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
cmd->t_task_cdb[0], cmd->tag);
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_status(cmd);
if (ret) {
transport_handle_queue_full(cmd, cmd->se_dev,
ret, false);
return;
}
} else {
cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
cmd->se_tfo->queue_tm_rsp(cmd);
}
} else {
/*
* Allow the fabric driver to unmap any resources before
* releasing the descriptor via TFO->release_cmd().
*/
cmd->se_tfo->aborted_task(cmd);
if (ack_kref)
WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
/*
* To do: establish a unit attention condition on the I_T
* nexus associated with cmd. See also the paragraph "Aborting
* commands" in SAM.
*/
}
WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
transport_cmd_check_stop_to_fabric(cmd);
}
static void target_abort_work(struct work_struct *work)
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
target_handle_abort(cmd);
}
static bool target_cmd_interrupted(struct se_cmd *cmd)
{
int post_ret;
if (cmd->transport_state & CMD_T_ABORTED) {
if (cmd->transport_complete_callback)
cmd->transport_complete_callback(cmd, false, &post_ret);
INIT_WORK(&cmd->work, target_abort_work);
queue_work(target_completion_wq, &cmd->work);
return true;
} else if (cmd->transport_state & CMD_T_STOP) {
if (cmd->transport_complete_callback)
cmd->transport_complete_callback(cmd, false, &post_ret);
complete_all(&cmd->t_transport_stop_comp);
return true;
}
return false;
}
/* May be called from interrupt context so must not sleep. */
void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
{
int success;
unsigned long flags;
if (target_cmd_interrupted(cmd))
return;
cmd->scsi_status = scsi_status;
spin_lock_irqsave(&cmd->t_state_lock, flags);
switch (cmd->scsi_status) {
case SAM_STAT_CHECK_CONDITION:
if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
success = 1;
else
success = 0;
break;
default:
success = 1;
break;
}
cmd->t_state = TRANSPORT_COMPLETE;
cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
INIT_WORK(&cmd->work, success ? target_complete_ok_work :
target_complete_failure_work);
if (cmd->se_cmd_flags & SCF_USE_CPUID)
queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
else
queue_work(target_completion_wq, &cmd->work);
}
EXPORT_SYMBOL(target_complete_cmd);
void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
{
if ((scsi_status == SAM_STAT_GOOD ||
cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
length < cmd->data_length) {
if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
cmd->residual_count += cmd->data_length - length;
} else {
cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
cmd->residual_count = cmd->data_length - length;
}
cmd->data_length = length;
}
target_complete_cmd(cmd, scsi_status);
}
EXPORT_SYMBOL(target_complete_cmd_with_length);
static void target_add_to_state_list(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned long flags;
spin_lock_irqsave(&dev->execute_task_lock, flags);
if (!cmd->state_active) {
list_add_tail(&cmd->state_list, &dev->state_list);
cmd->state_active = true;
}
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
/*
* Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
*/
static void transport_write_pending_qf(struct se_cmd *cmd);
static void transport_complete_qf(struct se_cmd *cmd);
void target_qf_do_work(struct work_struct *work)
{
struct se_device *dev = container_of(work, struct se_device,
qf_work_queue);
LIST_HEAD(qf_cmd_list);
struct se_cmd *cmd, *cmd_tmp;
spin_lock_irq(&dev->qf_cmd_lock);
list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
spin_unlock_irq(&dev->qf_cmd_lock);
list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
list_del(&cmd->se_qf_node);
atomic_dec_mb(&dev->dev_qf_count);
pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
" context: %s\n", cmd->se_tfo->fabric_name, cmd,
(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
: "UNKNOWN");
if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
transport_write_pending_qf(cmd);
else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
transport_complete_qf(cmd);
}
}
unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
{
switch (cmd->data_direction) {
case DMA_NONE:
return "NONE";
case DMA_FROM_DEVICE:
return "READ";
case DMA_TO_DEVICE:
return "WRITE";
case DMA_BIDIRECTIONAL:
return "BIDI";
default:
break;
}
return "UNKNOWN";
}
void transport_dump_dev_state(
struct se_device *dev,
char *b,
int *bl)
{
*bl += sprintf(b + *bl, "Status: ");
if (dev->export_count)
*bl += sprintf(b + *bl, "ACTIVATED");
else
*bl += sprintf(b + *bl, "DEACTIVATED");
*bl += sprintf(b + *bl, " Max Queue Depth: %d", dev->queue_depth);
*bl += sprintf(b + *bl, " SectorSize: %u HwMaxSectors: %u\n",
dev->dev_attrib.block_size,
dev->dev_attrib.hw_max_sectors);
*bl += sprintf(b + *bl, " ");
}
void transport_dump_vpd_proto_id(
struct t10_vpd *vpd,
unsigned char *p_buf,
int p_buf_len)
{
unsigned char buf[VPD_TMP_BUF_SIZE];
int len;
memset(buf, 0, VPD_TMP_BUF_SIZE);
len = sprintf(buf, "T10 VPD Protocol Identifier: ");
switch (vpd->protocol_identifier) {
case 0x00:
sprintf(buf+len, "Fibre Channel\n");
break;
case 0x10:
sprintf(buf+len, "Parallel SCSI\n");
break;
case 0x20:
sprintf(buf+len, "SSA\n");
break;
case 0x30:
sprintf(buf+len, "IEEE 1394\n");
break;
case 0x40:
sprintf(buf+len, "SCSI Remote Direct Memory Access"
" Protocol\n");
break;
case 0x50:
sprintf(buf+len, "Internet SCSI (iSCSI)\n");
break;
case 0x60:
sprintf(buf+len, "SAS Serial SCSI Protocol\n");
break;
case 0x70:
sprintf(buf+len, "Automation/Drive Interface Transport"
" Protocol\n");
break;
case 0x80:
sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
break;
default:
sprintf(buf+len, "Unknown 0x%02x\n",
vpd->protocol_identifier);
break;
}
if (p_buf)
strncpy(p_buf, buf, p_buf_len);
else
pr_debug("%s", buf);
}
void
transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
{
/*
* Check if the Protocol Identifier Valid (PIV) bit is set..
*
* from spc3r23.pdf section 7.5.1
*/
if (page_83[1] & 0x80) {
vpd->protocol_identifier = (page_83[0] & 0xf0);
vpd->protocol_identifier_set = 1;
transport_dump_vpd_proto_id(vpd, NULL, 0);
}
}
EXPORT_SYMBOL(transport_set_vpd_proto_id);
int transport_dump_vpd_assoc(
struct t10_vpd *vpd,
unsigned char *p_buf,
int p_buf_len)
{
unsigned char buf[VPD_TMP_BUF_SIZE];
int ret = 0;
int len;
memset(buf, 0, VPD_TMP_BUF_SIZE);
len = sprintf(buf, "T10 VPD Identifier Association: ");
switch (vpd->association) {
case 0x00:
sprintf(buf+len, "addressed logical unit\n");
break;
case 0x10:
sprintf(buf+len, "target port\n");
break;
case 0x20:
sprintf(buf+len, "SCSI target device\n");
break;
default:
sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
ret = -EINVAL;
break;
}
if (p_buf)
strncpy(p_buf, buf, p_buf_len);
else
pr_debug("%s", buf);
return ret;
}
int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
{
/*
* The VPD identification association..
*
* from spc3r23.pdf Section 7.6.3.1 Table 297
*/
vpd->association = (page_83[1] & 0x30);
return transport_dump_vpd_assoc(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_assoc);
int transport_dump_vpd_ident_type(
struct t10_vpd *vpd,
unsigned char *p_buf,
int p_buf_len)
{
unsigned char buf[VPD_TMP_BUF_SIZE];
int ret = 0;
int len;
memset(buf, 0, VPD_TMP_BUF_SIZE);
len = sprintf(buf, "T10 VPD Identifier Type: ");
switch (vpd->device_identifier_type) {
case 0x00:
sprintf(buf+len, "Vendor specific\n");
break;
case 0x01:
sprintf(buf+len, "T10 Vendor ID based\n");
break;
case 0x02:
sprintf(buf+len, "EUI-64 based\n");
break;
case 0x03:
sprintf(buf+len, "NAA\n");
break;
case 0x04:
sprintf(buf+len, "Relative target port identifier\n");
break;
case 0x08:
sprintf(buf+len, "SCSI name string\n");
break;
default:
sprintf(buf+len, "Unsupported: 0x%02x\n",
vpd->device_identifier_type);
ret = -EINVAL;
break;
}
if (p_buf) {
if (p_buf_len < strlen(buf)+1)
return -EINVAL;
strncpy(p_buf, buf, p_buf_len);
} else {
pr_debug("%s", buf);
}
return ret;
}
int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
{
/*
* The VPD identifier type..
*
* from spc3r23.pdf Section 7.6.3.1 Table 298
*/
vpd->device_identifier_type = (page_83[1] & 0x0f);
return transport_dump_vpd_ident_type(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_ident_type);
int transport_dump_vpd_ident(
struct t10_vpd *vpd,
unsigned char *p_buf,
int p_buf_len)
{
unsigned char buf[VPD_TMP_BUF_SIZE];
int ret = 0;
memset(buf, 0, VPD_TMP_BUF_SIZE);
switch (vpd->device_identifier_code_set) {
case 0x01: /* Binary */
snprintf(buf, sizeof(buf),
"T10 VPD Binary Device Identifier: %s\n",
&vpd->device_identifier[0]);
break;
case 0x02: /* ASCII */
snprintf(buf, sizeof(buf),
"T10 VPD ASCII Device Identifier: %s\n",
&vpd->device_identifier[0]);
break;
case 0x03: /* UTF-8 */
snprintf(buf, sizeof(buf),
"T10 VPD UTF-8 Device Identifier: %s\n",
&vpd->device_identifier[0]);
break;
default:
sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
" 0x%02x", vpd->device_identifier_code_set);
ret = -EINVAL;
break;
}
if (p_buf)
strncpy(p_buf, buf, p_buf_len);
else
pr_debug("%s", buf);
return ret;
}
int
transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
{
static const char hex_str[] = "0123456789abcdef";
int j = 0, i = 4; /* offset to start of the identifier */
/*
* The VPD Code Set (encoding)
*
* from spc3r23.pdf Section 7.6.3.1 Table 296
*/
vpd->device_identifier_code_set = (page_83[0] & 0x0f);
switch (vpd->device_identifier_code_set) {
case 0x01: /* Binary */
vpd->device_identifier[j++] =
hex_str[vpd->device_identifier_type];
while (i < (4 + page_83[3])) {
vpd->device_identifier[j++] =
hex_str[(page_83[i] & 0xf0) >> 4];
vpd->device_identifier[j++] =
hex_str[page_83[i] & 0x0f];
i++;
}
break;
case 0x02: /* ASCII */
case 0x03: /* UTF-8 */
while (i < (4 + page_83[3]))
vpd->device_identifier[j++] = page_83[i++];
break;
default:
break;
}
return transport_dump_vpd_ident(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_ident);
static sense_reason_t
target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
unsigned int size)
{
u32 mtl;
if (!cmd->se_tfo->max_data_sg_nents)
return TCM_NO_SENSE;
/*
* Check if fabric enforced maximum SGL entries per I/O descriptor
* exceeds se_cmd->data_length. If true, set SCF_UNDERFLOW_BIT +
* residual_count and reduce original cmd->data_length to maximum
* length based on single PAGE_SIZE entry scatter-lists.
*/
mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
if (cmd->data_length > mtl) {
/*
* If an existing CDB overflow is present, calculate new residual
* based on CDB size minus fabric maximum transfer length.
*
* If an existing CDB underflow is present, calculate new residual
* based on original cmd->data_length minus fabric maximum transfer
* length.
*
* Otherwise, set the underflow residual based on cmd->data_length
* minus fabric maximum transfer length.
*/
if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
cmd->residual_count = (size - mtl);
} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
u32 orig_dl = size + cmd->residual_count;
cmd->residual_count = (orig_dl - mtl);
} else {
cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
cmd->residual_count = (cmd->data_length - mtl);
}
cmd->data_length = mtl;
/*
* Reset sbc_check_prot() calculated protection payload
* length based upon the new smaller MTL.
*/
if (cmd->prot_length) {
u32 sectors = (mtl / dev->dev_attrib.block_size);
cmd->prot_length = dev->prot_length * sectors;
}
}
return TCM_NO_SENSE;
}
sense_reason_t
target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
{
struct se_device *dev = cmd->se_dev;
if (cmd->unknown_data_length) {
cmd->data_length = size;
} else if (size != cmd->data_length) {
pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
" %u does not match SCSI CDB Length: %u for SAM Opcode:"
" 0x%02x\n", cmd->se_tfo->fabric_name,
cmd->data_length, size, cmd->t_task_cdb[0]);
if (cmd->data_direction == DMA_TO_DEVICE) {
if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
pr_err_ratelimited("Rejecting underflow/overflow"
" for WRITE data CDB\n");
return TCM_INVALID_CDB_FIELD;
}
/*
* Some fabric drivers like iscsi-target still expect to
* always reject overflow writes. Reject this case until
* full fabric driver level support for overflow writes
* is introduced tree-wide.
*/
if (size > cmd->data_length) {
pr_err_ratelimited("Rejecting overflow for"
" WRITE control CDB\n");
return TCM_INVALID_CDB_FIELD;
}
}
/*
* Reject READ_* or WRITE_* with overflow/underflow for
* type SCF_SCSI_DATA_CDB.
*/
if (dev->dev_attrib.block_size != 512) {
pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
" CDB on non 512-byte sector setup subsystem"
" plugin: %s\n", dev->transport->name);
/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
return TCM_INVALID_CDB_FIELD;
}
/*
* For the overflow case keep the existing fabric provided
* ->data_length. Otherwise for the underflow case, reset
* ->data_length to the smaller SCSI expected data transfer
* length.
*/
if (size > cmd->data_length) {
cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
cmd->residual_count = (size - cmd->data_length);
} else {
cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
cmd->residual_count = (cmd->data_length - size);
cmd->data_length = size;
}
}
return target_check_max_data_sg_nents(cmd, dev, size);
}
/*
* Used by fabric modules containing a local struct se_cmd within their
* fabric dependent per I/O descriptor.
*
* Preserves the value of @cmd->tag.
*/
void transport_init_se_cmd(
struct se_cmd *cmd,
const struct target_core_fabric_ops *tfo,
struct se_session *se_sess,
u32 data_length,
int data_direction,
int task_attr,
unsigned char *sense_buffer)
{
INIT_LIST_HEAD(&cmd->se_delayed_node);
INIT_LIST_HEAD(&cmd->se_qf_node);
INIT_LIST_HEAD(&cmd->se_cmd_list);
INIT_LIST_HEAD(&cmd->state_list);
init_completion(&cmd->t_transport_stop_comp);
cmd->free_compl = NULL;
cmd->abrt_compl = NULL;
spin_lock_init(&cmd->t_state_lock);
INIT_WORK(&cmd->work, NULL);
kref_init(&cmd->cmd_kref);
cmd->se_tfo = tfo;
cmd->se_sess = se_sess;
cmd->data_length = data_length;
cmd->data_direction = data_direction;
cmd->sam_task_attr = task_attr;
cmd->sense_buffer = sense_buffer;
cmd->state_active = false;
}
EXPORT_SYMBOL(transport_init_se_cmd);
static sense_reason_t
transport_check_alloc_task_attr(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
/*
* Check if SAM Task Attribute emulation is enabled for this
* struct se_device storage object
*/
if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
return 0;
if (cmd->sam_task_attr == TCM_ACA_TAG) {
pr_debug("SAM Task Attribute ACA"
" emulation is not supported\n");
return TCM_INVALID_CDB_FIELD;
}
return 0;
}
sense_reason_t
target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
{
struct se_device *dev = cmd->se_dev;
sense_reason_t ret;
/*
* Ensure that the received CDB is less than the max (252 + 8) bytes
* for VARIABLE_LENGTH_CMD
*/
if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
pr_err("Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
return TCM_INVALID_CDB_FIELD;
}
/*
* If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
* allocate the additional extended CDB buffer now.. Otherwise
* setup the pointer from __t_task_cdb to t_task_cdb.
*/
if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
GFP_KERNEL);
if (!cmd->t_task_cdb) {
pr_err("Unable to allocate cmd->t_task_cdb"
" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
scsi_command_size(cdb),
(unsigned long)sizeof(cmd->__t_task_cdb));
return TCM_OUT_OF_RESOURCES;
}
} else
cmd->t_task_cdb = &cmd->__t_task_cdb[0];
/*
* Copy the original CDB into cmd->
*/
memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
trace_target_sequencer_start(cmd);
ret = dev->transport->parse_cdb(cmd);
if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
cmd->se_tfo->fabric_name,
cmd->se_sess->se_node_acl->initiatorname,
cmd->t_task_cdb[0]);
if (ret)
return ret;
ret = transport_check_alloc_task_attr(cmd);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
return 0;
}
EXPORT_SYMBOL(target_setup_cmd_from_cdb);
/*
* Used by fabric module frontends to queue tasks directly.
* May only be used from process context.
*/
int transport_handle_cdb_direct(
struct se_cmd *cmd)
{
sense_reason_t ret;
if (!cmd->se_lun) {
dump_stack();
pr_err("cmd->se_lun is NULL\n");
return -EINVAL;
}
if (in_interrupt()) {
dump_stack();
pr_err("transport_generic_handle_cdb cannot be called"
" from interrupt context\n");
return -EINVAL;
}
/*
* Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
* outstanding descriptors are handled correctly during shutdown via
* transport_wait_for_tasks()
*
* Also, we don't take cmd->t_state_lock here as we only expect
* this to be called for initial descriptor submission.
*/
cmd->t_state = TRANSPORT_NEW_CMD;
cmd->transport_state |= CMD_T_ACTIVE;
/*
* transport_generic_new_cmd() is already handling QUEUE_FULL,
* so follow TRANSPORT_NEW_CMD processing thread context usage
* and call transport_generic_request_failure() if necessary..
*/
ret = transport_generic_new_cmd(cmd);
if (ret)
transport_generic_request_failure(cmd, ret);
return 0;
}
EXPORT_SYMBOL(transport_handle_cdb_direct);
sense_reason_t
transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
{
if (!sgl || !sgl_count)
return 0;
/*
* Reject SCSI data overflow with map_mem_to_cmd() as incoming
* scatterlists already have been set to follow what the fabric
* passes for the original expected data transfer length.
*/
if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
pr_warn("Rejecting SCSI DATA overflow for fabric using"
" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
return TCM_INVALID_CDB_FIELD;
}
cmd->t_data_sg = sgl;
cmd->t_data_nents = sgl_count;
cmd->t_bidi_data_sg = sgl_bidi;
cmd->t_bidi_data_nents = sgl_bidi_count;
cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
return 0;
}
/**
* target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
* se_cmd + use pre-allocated SGL memory.
*
* @se_cmd: command descriptor to submit
* @se_sess: associated se_sess for endpoint
* @cdb: pointer to SCSI CDB
* @sense: pointer to SCSI sense buffer
* @unpacked_lun: unpacked LUN to reference for struct se_lun
* @data_length: fabric expected data transfer length
* @task_attr: SAM task attribute
* @data_dir: DMA data direction
* @flags: flags for command submission from target_sc_flags_tables
* @sgl: struct scatterlist memory for unidirectional mapping
* @sgl_count: scatterlist count for unidirectional mapping
* @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
* @sgl_bidi_count: scatterlist count for bidirectional READ mapping
* @sgl_prot: struct scatterlist memory protection information
* @sgl_prot_count: scatterlist count for protection information
*
* Task tags are supported if the caller has set @se_cmd->tag.
*
* Returns non zero to signal active I/O shutdown failure. All other
* setup exceptions will be returned as a SCSI CHECK_CONDITION response,
* but still return zero here.
*
* This may only be called from process context, and also currently
* assumes internal allocation of fabric payload buffer by target-core.
*/
int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
u32 data_length, int task_attr, int data_dir, int flags,
struct scatterlist *sgl, u32 sgl_count,
struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
struct scatterlist *sgl_prot, u32 sgl_prot_count)
{
struct se_portal_group *se_tpg;
sense_reason_t rc;
int ret;
se_tpg = se_sess->se_tpg;
BUG_ON(!se_tpg);
BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
BUG_ON(in_interrupt());
/*
* Initialize se_cmd for target operation. From this point
* exceptions are handled by sending exception status via
* target_core_fabric_ops->queue_status() callback
*/
transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
data_length, data_dir, task_attr, sense);
if (flags & TARGET_SCF_USE_CPUID)
se_cmd->se_cmd_flags |= SCF_USE_CPUID;
else
se_cmd->cpuid = WORK_CPU_UNBOUND;
if (flags & TARGET_SCF_UNKNOWN_SIZE)
se_cmd->unknown_data_length = 1;
/*
* Obtain struct se_cmd->cmd_kref reference and add new cmd to
* se_sess->sess_cmd_list. A second kref_get here is necessary
* for fabrics using TARGET_SCF_ACK_KREF that expect a second
* kref_put() to happen during fabric packet acknowledgement.
*/
ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
if (ret)
return ret;
/*
* Signal bidirectional data payloads to target-core
*/
if (flags & TARGET_SCF_BIDI_OP)
se_cmd->se_cmd_flags |= SCF_BIDI;
/*
* Locate se_lun pointer and attach it to struct se_cmd
*/
rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
if (rc) {
transport_send_check_condition_and_sense(se_cmd, rc, 0);
target_put_sess_cmd(se_cmd);
return 0;
}
rc = target_setup_cmd_from_cdb(se_cmd, cdb);
if (rc != 0) {
transport_generic_request_failure(se_cmd, rc);
return 0;
}
/*
* Save pointers for SGLs containing protection information,
* if present.
*/
if (sgl_prot_count) {
se_cmd->t_prot_sg = sgl_prot;
se_cmd->t_prot_nents = sgl_prot_count;
se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
}
/*
* When a non zero sgl_count has been passed perform SGL passthrough
* mapping for pre-allocated fabric memory instead of having target
* core perform an internal SGL allocation..
*/
if (sgl_count != 0) {
BUG_ON(!sgl);
/*
* A work-around for tcm_loop as some userspace code via
* scsi-generic do not memset their associated read buffers,
* so go ahead and do that here for type non-data CDBs. Also
* note that this is currently guaranteed to be a single SGL
* for this case by target core in target_setup_cmd_from_cdb()
* -> transport_generic_cmd_sequencer().
*/
if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
se_cmd->data_direction == DMA_FROM_DEVICE) {
unsigned char *buf = NULL;
if (sgl)
buf = kmap(sg_page(sgl)) + sgl->offset;
if (buf) {
memset(buf, 0, sgl->length);
kunmap(sg_page(sgl));
}
}
rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
sgl_bidi, sgl_bidi_count);
if (rc != 0) {
transport_generic_request_failure(se_cmd, rc);
return 0;
}
}
/*
* Check if we need to delay processing because of ALUA
* Active/NonOptimized primary access state..
*/
core_alua_check_nonop_delay(se_cmd);
transport_handle_cdb_direct(se_cmd);
return 0;
}
EXPORT_SYMBOL(target_submit_cmd_map_sgls);
/**
* target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
*
* @se_cmd: command descriptor to submit
* @se_sess: associated se_sess for endpoint
* @cdb: pointer to SCSI CDB
* @sense: pointer to SCSI sense buffer
* @unpacked_lun: unpacked LUN to reference for struct se_lun
* @data_length: fabric expected data transfer length
* @task_attr: SAM task attribute
* @data_dir: DMA data direction
* @flags: flags for command submission from target_sc_flags_tables
*
* Task tags are supported if the caller has set @se_cmd->tag.
*
* Returns non zero to signal active I/O shutdown failure. All other
* setup exceptions will be returned as a SCSI CHECK_CONDITION response,
* but still return zero here.
*
* This may only be called from process context, and also currently
* assumes internal allocation of fabric payload buffer by target-core.
*
* It also assumes interal target core SGL memory allocation.
*/
int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
u32 data_length, int task_attr, int data_dir, int flags)
{
return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
unpacked_lun, data_length, task_attr, data_dir,
flags, NULL, 0, NULL, 0, NULL, 0);
}
EXPORT_SYMBOL(target_submit_cmd);
static void target_complete_tmr_failure(struct work_struct *work)
{
struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
se_cmd->se_tfo->queue_tm_rsp(se_cmd);
transport_cmd_check_stop_to_fabric(se_cmd);
}
static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
u64 *unpacked_lun)
{
struct se_cmd *se_cmd;
unsigned long flags;
bool ret = false;
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
continue;
if (se_cmd->tag == tag) {
*unpacked_lun = se_cmd->orig_fe_lun;
ret = true;
break;
}
}
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
return ret;
}
/**
* target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
* for TMR CDBs
*
* @se_cmd: command descriptor to submit
* @se_sess: associated se_sess for endpoint
* @sense: pointer to SCSI sense buffer
* @unpacked_lun: unpacked LUN to reference for struct se_lun
* @fabric_tmr_ptr: fabric context for TMR req
* @tm_type: Type of TM request
* @gfp: gfp type for caller
* @tag: referenced task tag for TMR_ABORT_TASK
* @flags: submit cmd flags
*
* Callable from all contexts.
**/
int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
unsigned char *sense, u64 unpacked_lun,
void *fabric_tmr_ptr, unsigned char tm_type,
gfp_t gfp, u64 tag, int flags)
{
struct se_portal_group *se_tpg;
int ret;
se_tpg = se_sess->se_tpg;
BUG_ON(!se_tpg);
transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
0, DMA_NONE, TCM_SIMPLE_TAG, sense);
/*
* FIXME: Currently expect caller to handle se_cmd->se_tmr_req
* allocation failure.
*/
ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
if (ret < 0)
return -ENOMEM;
if (tm_type == TMR_ABORT_TASK)
se_cmd->se_tmr_req->ref_task_tag = tag;
/* See target_submit_cmd for commentary */
ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
if (ret) {
core_tmr_release_req(se_cmd->se_tmr_req);
return ret;
}
/*
* If this is ABORT_TASK with no explicit fabric provided LUN,
* go ahead and search active session tags for a match to figure
* out unpacked_lun for the original se_cmd.
*/
if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
goto failure;
}
ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
if (ret)
goto failure;
transport_generic_handle_tmr(se_cmd);
return 0;
/*
* For callback during failure handling, push this work off
* to process context with TMR_LUN_DOES_NOT_EXIST status.
*/
failure:
INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
schedule_work(&se_cmd->work);
return 0;
}
EXPORT_SYMBOL(target_submit_tmr);
/*
* Handle SAM-esque emulation for generic transport request failures.
*/
void transport_generic_request_failure(struct se_cmd *cmd,
sense_reason_t sense_reason)
{
int ret = 0, post_ret;
pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
sense_reason);
target_show_cmd("-----[ ", cmd);
/*
* For SAM Task Attribute emulation for failed struct se_cmd
*/
transport_complete_task_attr(cmd);
if (cmd->transport_complete_callback)
cmd->transport_complete_callback(cmd, false, &post_ret);
if (cmd->transport_state & CMD_T_ABORTED) {
INIT_WORK(&cmd->work, target_abort_work);
queue_work(target_completion_wq, &cmd->work);
return;
}
switch (sense_reason) {
case TCM_NON_EXISTENT_LUN:
case TCM_UNSUPPORTED_SCSI_OPCODE:
case TCM_INVALID_CDB_FIELD:
case TCM_INVALID_PARAMETER_LIST:
case TCM_PARAMETER_LIST_LENGTH_ERROR:
case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
case TCM_UNKNOWN_MODE_PAGE:
case TCM_WRITE_PROTECTED:
case TCM_ADDRESS_OUT_OF_RANGE:
case TCM_CHECK_CONDITION_ABORT_CMD:
case TCM_CHECK_CONDITION_UNIT_ATTENTION:
case TCM_CHECK_CONDITION_NOT_READY:
case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
case TCM_TOO_MANY_TARGET_DESCS:
case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
case TCM_TOO_MANY_SEGMENT_DESCS:
case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
break;
case TCM_OUT_OF_RESOURCES:
cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
goto queue_status;
case TCM_LUN_BUSY:
cmd->scsi_status = SAM_STAT_BUSY;
goto queue_status;
case TCM_RESERVATION_CONFLICT:
/*
* No SENSE Data payload for this case, set SCSI Status
* and queue the response to $FABRIC_MOD.
*
* Uses linux/include/scsi/scsi.h SAM status codes defs
*/
cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
/*
* For UA Interlock Code 11b, a RESERVATION CONFLICT will
* establish a UNIT ATTENTION with PREVIOUS RESERVATION
* CONFLICT STATUS.
*
* See spc4r17, section 7.4.6 Control Mode Page, Table 349
*/
if (cmd->se_sess &&
cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
target_ua_allocate_lun(cmd->se_sess->se_node_acl,
cmd->orig_fe_lun, 0x2C,
ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
}
goto queue_status;
default:
pr_err("Unknown transport error for CDB 0x%02x: %d\n",
cmd->t_task_cdb[0], sense_reason);
sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
break;
}
ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
if (ret)
goto queue_full;
check_stop:
transport_cmd_check_stop_to_fabric(cmd);
return;
queue_status:
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_status(cmd);
if (!ret)
goto check_stop;
queue_full:
transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
}
EXPORT_SYMBOL(transport_generic_request_failure);
void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
{
sense_reason_t ret;
if (!cmd->execute_cmd) {
ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
goto err;
}
if (do_checks) {
/*
* Check for an existing UNIT ATTENTION condition after
* target_handle_task_attr() has done SAM task attr
* checking, and possibly have already defered execution
* out to target_restart_delayed_cmds() context.
*/
ret = target_scsi3_ua_check(cmd);
if (ret)
goto err;
ret = target_alua_state_check(cmd);
if (ret)
goto err;
ret = target_check_reservation(cmd);
if (ret) {
cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
goto err;
}
}
ret = cmd->execute_cmd(cmd);
if (!ret)
return;
err:
spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state &= ~CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
transport_generic_request_failure(cmd, ret);
}
static int target_write_prot_action(struct se_cmd *cmd)
{
u32 sectors;
/*
* Perform WRITE_INSERT of PI using software emulation when backend
* device has PI enabled, if the transport has not already generated
* PI using hardware WRITE_INSERT offload.
*/
switch (cmd->prot_op) {
case TARGET_PROT_DOUT_INSERT:
if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
sbc_dif_generate(cmd);
break;
case TARGET_PROT_DOUT_STRIP:
if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
break;
sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
sectors, 0, cmd->t_prot_sg, 0);
if (unlikely(cmd->pi_err)) {
spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state &= ~CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
transport_generic_request_failure(cmd, cmd->pi_err);
return -1;
}
break;
default:
break;
}
return 0;
}
static bool target_handle_task_attr(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
return false;
cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
/*
* Check for the existence of HEAD_OF_QUEUE, and if true return 1
* to allow the passed struct se_cmd list of tasks to the front of the list.
*/
switch (cmd->sam_task_attr) {
case TCM_HEAD_TAG:
pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
cmd->t_task_cdb[0]);
return false;
case TCM_ORDERED_TAG:
atomic_inc_mb(&dev->dev_ordered_sync);
pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
cmd->t_task_cdb[0]);
/*
* Execute an ORDERED command if no other older commands
* exist that need to be completed first.
*/
if (!atomic_read(&dev->simple_cmds))
return false;
break;
default:
/*
* For SIMPLE and UNTAGGED Task Attribute commands
*/
atomic_inc_mb(&dev->simple_cmds);
break;
}
if (atomic_read(&dev->dev_ordered_sync) == 0)
return false;
spin_lock(&dev->delayed_cmd_lock);
list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
spin_unlock(&dev->delayed_cmd_lock);
pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
cmd->t_task_cdb[0], cmd->sam_task_attr);
return true;
}
void target_execute_cmd(struct se_cmd *cmd)
{
/*
* Determine if frontend context caller is requesting the stopping of
* this command for frontend exceptions.
*
* If the received CDB has already been aborted stop processing it here.
*/
if (target_cmd_interrupted(cmd))
return;
spin_lock_irq(&cmd->t_state_lock);
cmd->t_state = TRANSPORT_PROCESSING;
cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
if (target_write_prot_action(cmd))
return;
if (target_handle_task_attr(cmd)) {
spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state &= ~CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
return;
}
__target_execute_cmd(cmd, true);
}
EXPORT_SYMBOL(target_execute_cmd);
/*
* Process all commands up to the last received ORDERED task attribute which
* requires another blocking boundary
*/
static void target_restart_delayed_cmds(struct se_device *dev)
{
for (;;) {
struct se_cmd *cmd;
spin_lock(&dev->delayed_cmd_lock);
if (list_empty(&dev->delayed_cmd_list)) {
spin_unlock(&dev->delayed_cmd_lock);
break;
}
cmd = list_entry(dev->delayed_cmd_list.next,
struct se_cmd, se_delayed_node);
list_del(&cmd->se_delayed_node);
spin_unlock(&dev->delayed_cmd_lock);
cmd->transport_state |= CMD_T_SENT;
__target_execute_cmd(cmd, true);
if (cmd->sam_task_attr == TCM_ORDERED_TAG)
break;
}
}
/*
* Called from I/O completion to determine which dormant/delayed
* and ordered cmds need to have their tasks added to the execution queue.
*/
static void transport_complete_task_attr(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
return;
if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
goto restart;
if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
atomic_dec_mb(&dev->simple_cmds);
dev->dev_cur_ordered_id++;
} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
dev->dev_cur_ordered_id++;
pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
dev->dev_cur_ordered_id);
} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
atomic_dec_mb(&dev->dev_ordered_sync);
dev->dev_cur_ordered_id++;
pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
dev->dev_cur_ordered_id);
}
cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
restart:
target_restart_delayed_cmds(dev);
}
static void transport_complete_qf(struct se_cmd *cmd)
{
int ret = 0;
transport_complete_task_attr(cmd);
/*
* If a fabric driver ->write_pending() or ->queue_data_in() callback
* has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
* the same callbacks should not be retried. Return CHECK_CONDITION
* if a scsi_status is not already set.
*
* If a fabric driver ->queue_status() has returned non zero, always
* keep retrying no matter what..
*/
if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
if (cmd->scsi_status)
goto queue_status;
translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
goto queue_status;
}
/*
* Check if we need to send a sense buffer from
* the struct se_cmd in question. We do NOT want
* to take this path of the IO has been marked as
* needing to be treated like a "normal read". This
* is the case if it's a tape read, and either the
* FM, EOM, or ILI bits are set, but there is no
* sense data.
*/
if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
goto queue_status;
switch (cmd->data_direction) {
case DMA_FROM_DEVICE:
/* queue status if not treating this as a normal read */
if (cmd->scsi_status &&
!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
goto queue_status;
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_data_in(cmd);
break;
case DMA_TO_DEVICE:
if (cmd->se_cmd_flags & SCF_BIDI) {
ret = cmd->se_tfo->queue_data_in(cmd);
break;
}
/* fall through */
case DMA_NONE:
queue_status:
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_status(cmd);
break;
default:
break;
}
if (ret < 0) {
transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
return;
}
transport_cmd_check_stop_to_fabric(cmd);
}
static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
int err, bool write_pending)
{
/*
* -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
* ->queue_data_in() callbacks from new process context.
*
* Otherwise for other errors, transport_complete_qf() will send
* CHECK_CONDITION via ->queue_status() instead of attempting to
* retry associated fabric driver data-transfer callbacks.
*/
if (err == -EAGAIN || err == -ENOMEM) {
cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
TRANSPORT_COMPLETE_QF_OK;
} else {
pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
}
spin_lock_irq(&dev->qf_cmd_lock);
list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
atomic_inc_mb(&dev->dev_qf_count);
spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
schedule_work(&cmd->se_dev->qf_work_queue);
}
static bool target_read_prot_action(struct se_cmd *cmd)
{
switch (cmd->prot_op) {
case TARGET_PROT_DIN_STRIP:
if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
u32 sectors = cmd->data_length >>
ilog2(cmd->se_dev->dev_attrib.block_size);
cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
sectors, 0, cmd->t_prot_sg,
0);
if (cmd->pi_err)
return true;
}
break;
case TARGET_PROT_DIN_INSERT:
if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
break;
sbc_dif_generate(cmd);
break;
default:
break;
}
return false;
}
static void target_complete_ok_work(struct work_struct *work)
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
int ret;
/*
* Check if we need to move delayed/dormant tasks from cmds on the
* delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
* Attribute.
*/
transport_complete_task_attr(cmd);
/*
* Check to schedule QUEUE_FULL work, or execute an existing
* cmd->transport_qf_callback()
*/
if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
schedule_work(&cmd->se_dev->qf_work_queue);
/*
* Check if we need to send a sense buffer from
* the struct se_cmd in question. We do NOT want
* to take this path of the IO has been marked as
* needing to be treated like a "normal read". This
* is the case if it's a tape read, and either the
* FM, EOM, or ILI bits are set, but there is no
* sense data.
*/
if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
WARN_ON(!cmd->scsi_status);
ret = transport_send_check_condition_and_sense(
cmd, 0, 1);
if (ret)
goto queue_full;
transport_cmd_check_stop_to_fabric(cmd);
return;
}
/*
* Check for a callback, used by amongst other things
* XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
*/
if (cmd->transport_complete_callback) {
sense_reason_t rc;
bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
bool zero_dl = !(cmd->data_length);
int post_ret = 0;
rc = cmd->transport_complete_callback(cmd, true, &post_ret);
if (!rc && !post_ret) {
if (caw && zero_dl)
goto queue_rsp;
return;
} else if (rc) {
ret = transport_send_check_condition_and_sense(cmd,
rc, 0);
if (ret)
goto queue_full;
transport_cmd_check_stop_to_fabric(cmd);
return;
}
}
queue_rsp:
switch (cmd->data_direction) {
case DMA_FROM_DEVICE:
/*
* if this is a READ-type IO, but SCSI status
* is set, then skip returning data and just
* return the status -- unless this IO is marked
* as needing to be treated as a normal read,
* in which case we want to go ahead and return
* the data. This happens, for example, for tape
* reads with the FM, EOM, or ILI bits set, with
* no sense data.
*/
if (cmd->scsi_status &&
!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
goto queue_status;
atomic_long_add(cmd->data_length,
&cmd->se_lun->lun_stats.tx_data_octets);
/*
* Perform READ_STRIP of PI using software emulation when
* backend had PI enabled, if the transport will not be
* performing hardware READ_STRIP offload.
*/
if (target_read_prot_action(cmd)) {
ret = transport_send_check_condition_and_sense(cmd,
cmd->pi_err, 0);
if (ret)
goto queue_full;
transport_cmd_check_stop_to_fabric(cmd);
return;
}
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_data_in(cmd);
if (ret)
goto queue_full;
break;
case DMA_TO_DEVICE:
atomic_long_add(cmd->data_length,
&cmd->se_lun->lun_stats.rx_data_octets);
/*
* Check if we need to send READ payload for BIDI-COMMAND
*/
if (cmd->se_cmd_flags & SCF_BIDI) {
atomic_long_add(cmd->data_length,
&cmd->se_lun->lun_stats.tx_data_octets);
ret = cmd->se_tfo->queue_data_in(cmd);
if (ret)
goto queue_full;
break;
}
/* fall through */
case DMA_NONE:
queue_status:
trace_target_cmd_complete(cmd);
ret = cmd->se_tfo->queue_status(cmd);
if (ret)
goto queue_full;
break;
default:
break;
}
transport_cmd_check_stop_to_fabric(cmd);
return;
queue_full:
pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
" data_direction: %d\n", cmd, cmd->data_direction);
transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
}
void target_free_sgl(struct scatterlist *sgl, int nents)
{
sgl_free_n_order(sgl, nents, 0);
}
EXPORT_SYMBOL(target_free_sgl);
static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
{
/*
* Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
* emulation, and free + reset pointers if necessary..
*/
if (!cmd->t_data_sg_orig)
return;
kfree(cmd->t_data_sg);
cmd->t_data_sg = cmd->t_data_sg_orig;
cmd->t_data_sg_orig = NULL;
cmd->t_data_nents = cmd->t_data_nents_orig;
cmd->t_data_nents_orig = 0;
}
static inline void transport_free_pages(struct se_cmd *cmd)
{
if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
cmd->t_prot_sg = NULL;
cmd->t_prot_nents = 0;
}
if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
/*
* Release special case READ buffer payload required for
* SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
*/
if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
target_free_sgl(cmd->t_bidi_data_sg,
cmd->t_bidi_data_nents);
cmd->t_bidi_data_sg = NULL;
cmd->t_bidi_data_nents = 0;
}
transport_reset_sgl_orig(cmd);
return;
}
transport_reset_sgl_orig(cmd);
target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
cmd->t_data_sg = NULL;
cmd->t_data_nents = 0;
target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
cmd->t_bidi_data_sg = NULL;
cmd->t_bidi_data_nents = 0;
}
void *transport_kmap_data_sg(struct se_cmd *cmd)
{
struct scatterlist *sg = cmd->t_data_sg;
struct page **pages;
int i;
/*
* We need to take into account a possible offset here for fabrics like
* tcm_loop who may be using a contig buffer from the SCSI midlayer for
* control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
*/
if (!cmd->t_data_nents)
return NULL;
BUG_ON(!sg);
if (cmd->t_data_nents == 1)
return kmap(sg_page(sg)) + sg->offset;
/* >1 page. use vmap */
pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
if (!pages)
return NULL;
/* convert sg[] to pages[] */
for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
pages[i] = sg_page(sg);
}
cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL);
kfree(pages);
if (!cmd->t_data_vmap)
return NULL;
return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
}
EXPORT_SYMBOL(transport_kmap_data_sg);
void transport_kunmap_data_sg(struct se_cmd *cmd)
{
if (!cmd->t_data_nents) {
return;
} else if (cmd->t_data_nents == 1) {
kunmap(sg_page(cmd->t_data_sg));
return;
}
vunmap(cmd->t_data_vmap);
cmd->t_data_vmap = NULL;
}
EXPORT_SYMBOL(transport_kunmap_data_sg);
int
target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
bool zero_page, bool chainable)
{
gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
*sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
return *sgl ? 0 : -ENOMEM;
}
EXPORT_SYMBOL(target_alloc_sgl);
/*
* Allocate any required resources to execute the command. For writes we
* might not have the payload yet, so notify the fabric via a call to
* ->write_pending instead. Otherwise place it on the execution queue.
*/
sense_reason_t
transport_generic_new_cmd(struct se_cmd *cmd)
{
unsigned long flags;
int ret = 0;
bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
if (cmd->prot_op != TARGET_PROT_NORMAL &&
!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
cmd->prot_length, true, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
/*
* Determine if the TCM fabric module has already allocated physical
* memory, and is directly calling transport_generic_map_mem_to_cmd()
* beforehand.
*/
if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
cmd->data_length) {
if ((cmd->se_cmd_flags & SCF_BIDI) ||
(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
u32 bidi_length;
if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
bidi_length = cmd->t_task_nolb *
cmd->se_dev->dev_attrib.block_size;
else
bidi_length = cmd->data_length;
ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
&cmd->t_bidi_data_nents,
bidi_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
cmd->data_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
cmd->data_length) {
/*
* Special case for COMPARE_AND_WRITE with fabrics
* using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
*/
u32 caw_length = cmd->t_task_nolb *
cmd->se_dev->dev_attrib.block_size;
ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
&cmd->t_bidi_data_nents,
caw_length, zero_flag, false);
if (ret < 0)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
/*
* If this command is not a write we can execute it right here,
* for write buffers we need to notify the fabric driver first
* and let it call back once the write buffers are ready.
*/
target_add_to_state_list(cmd);
if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
target_execute_cmd(cmd);
return 0;
}
spin_lock_irqsave(&cmd->t_state_lock, flags);
cmd->t_state = TRANSPORT_WRITE_PENDING;
/*
* Determine if frontend context caller is requesting the stopping of
* this command for frontend exceptions.
*/
if (cmd->transport_state & CMD_T_STOP &&
!cmd->se_tfo->write_pending_must_be_called) {
pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
__func__, __LINE__, cmd->tag);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete_all(&cmd->t_transport_stop_comp);
return 0;
}
cmd->transport_state &= ~CMD_T_ACTIVE;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
ret = cmd->se_tfo->write_pending(cmd);
if (ret)
goto queue_full;
return 0;
queue_full:
pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
return 0;
}
EXPORT_SYMBOL(transport_generic_new_cmd);
static void transport_write_pending_qf(struct se_cmd *cmd)
{
unsigned long flags;
int ret;
bool stop;
spin_lock_irqsave(&cmd->t_state_lock, flags);
stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
if (stop) {
pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
__func__, __LINE__, cmd->tag);
complete_all(&cmd->t_transport_stop_comp);
return;
}
ret = cmd->se_tfo->write_pending(cmd);
if (ret) {
pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
cmd);
transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
}
}
static bool
__transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
unsigned long *flags);
static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
{
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
/*
* Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
* finished.
*/
void target_put_cmd_and_wait(struct se_cmd *cmd)
{
DECLARE_COMPLETION_ONSTACK(compl);
WARN_ON_ONCE(cmd->abrt_compl);
cmd->abrt_compl = &compl;
target_put_sess_cmd(cmd);
wait_for_completion(&compl);
}
/*
* This function is called by frontend drivers after processing of a command
* has finished.
*
* The protocol for ensuring that either the regular frontend command
* processing flow or target_handle_abort() code drops one reference is as
* follows:
* - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
* the frontend driver to call this function synchronously or asynchronously.
* That will cause one reference to be dropped.
* - During regular command processing the target core sets CMD_T_COMPLETE
* before invoking one of the .queue_*() functions.
* - The code that aborts commands skips commands and TMFs for which
* CMD_T_COMPLETE has been set.
* - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
* commands that will be aborted.
* - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
* transport_generic_free_cmd() skips its call to target_put_sess_cmd().
* - For aborted commands for which CMD_T_TAS has been set .queue_status() will
* be called and will drop a reference.
* - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
* will be called. target_handle_abort() will drop the final reference.
*/
int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
{
DECLARE_COMPLETION_ONSTACK(compl);
int ret = 0;
bool aborted = false, tas = false;
if (wait_for_tasks)
target_wait_free_cmd(cmd, &aborted, &tas);
if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
/*
* Handle WRITE failure case where transport_generic_new_cmd()
* has already added se_cmd to state_list, but fabric has
* failed command before I/O submission.
*/
if (cmd->state_active)
target_remove_from_state_list(cmd);
}
if (aborted)
cmd->free_compl = &compl;
ret = target_put_sess_cmd(cmd);
if (aborted) {
pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
wait_for_completion(&compl);
ret = 1;
}
return ret;
}
EXPORT_SYMBOL(transport_generic_free_cmd);
/**
* target_get_sess_cmd - Add command to active ->sess_cmd_list
* @se_cmd: command descriptor to add
* @ack_kref: Signal that fabric will perform an ack target_put_sess_cmd()
*/
int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
{
struct se_session *se_sess = se_cmd->se_sess;
unsigned long flags;
int ret = 0;
/*
* Add a second kref if the fabric caller is expecting to handle
* fabric acknowledgement that requires two target_put_sess_cmd()
* invocations before se_cmd descriptor release.
*/
if (ack_kref) {
if (!kref_get_unless_zero(&se_cmd->cmd_kref))
return -EINVAL;
se_cmd->se_cmd_flags |= SCF_ACK_KREF;
}
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
if (se_sess->sess_tearing_down) {
ret = -ESHUTDOWN;
goto out;
}
list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
percpu_ref_get(&se_sess->cmd_count);
out:
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
if (ret && ack_kref)
target_put_sess_cmd(se_cmd);
return ret;
}
EXPORT_SYMBOL(target_get_sess_cmd);
static void target_free_cmd_mem(struct se_cmd *cmd)
{
transport_free_pages(cmd);
if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
core_tmr_release_req(cmd->se_tmr_req);
if (cmd->t_task_cdb != cmd->__t_task_cdb)
kfree(cmd->t_task_cdb);
}
static void target_release_cmd_kref(struct kref *kref)
{
struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
struct se_session *se_sess = se_cmd->se_sess;
struct completion *free_compl = se_cmd->free_compl;
struct completion *abrt_compl = se_cmd->abrt_compl;
unsigned long flags;
if (se_cmd->lun_ref_active)
percpu_ref_put(&se_cmd->se_lun->lun_ref);
if (se_sess) {
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
list_del_init(&se_cmd->se_cmd_list);
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
}
target_free_cmd_mem(se_cmd);
se_cmd->se_tfo->release_cmd(se_cmd);
if (free_compl)
complete(free_compl);
if (abrt_compl)
complete(abrt_compl);
percpu_ref_put(&se_sess->cmd_count);
}
/**
* target_put_sess_cmd - decrease the command reference count
* @se_cmd: command to drop a reference from
*
* Returns 1 if and only if this target_put_sess_cmd() call caused the
* refcount to drop to zero. Returns zero otherwise.
*/
int target_put_sess_cmd(struct se_cmd *se_cmd)
{
return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
}
EXPORT_SYMBOL(target_put_sess_cmd);
static const char *data_dir_name(enum dma_data_direction d)
{
switch (d) {
case DMA_BIDIRECTIONAL: return "BIDI";
case DMA_TO_DEVICE: return "WRITE";
case DMA_FROM_DEVICE: return "READ";
case DMA_NONE: return "NONE";
}
return "(?)";
}
static const char *cmd_state_name(enum transport_state_table t)
{
switch (t) {
case TRANSPORT_NO_STATE: return "NO_STATE";
case TRANSPORT_NEW_CMD: return "NEW_CMD";
case TRANSPORT_WRITE_PENDING: return "WRITE_PENDING";
case TRANSPORT_PROCESSING: return "PROCESSING";
case TRANSPORT_COMPLETE: return "COMPLETE";
case TRANSPORT_ISTATE_PROCESSING:
return "ISTATE_PROCESSING";
case TRANSPORT_COMPLETE_QF_WP: return "COMPLETE_QF_WP";
case TRANSPORT_COMPLETE_QF_OK: return "COMPLETE_QF_OK";
case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
}
return "(?)";
}
static void target_append_str(char **str, const char *txt)
{
char *prev = *str;
*str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
kstrdup(txt, GFP_ATOMIC);
kfree(prev);
}
/*
* Convert a transport state bitmask into a string. The caller is
* responsible for freeing the returned pointer.
*/
static char *target_ts_to_str(u32 ts)
{
char *str = NULL;
if (ts & CMD_T_ABORTED)
target_append_str(&str, "aborted");
if (ts & CMD_T_ACTIVE)
target_append_str(&str, "active");
if (ts & CMD_T_COMPLETE)
target_append_str(&str, "complete");
if (ts & CMD_T_SENT)
target_append_str(&str, "sent");
if (ts & CMD_T_STOP)
target_append_str(&str, "stop");
if (ts & CMD_T_FABRIC_STOP)
target_append_str(&str, "fabric_stop");
return str;
}
static const char *target_tmf_name(enum tcm_tmreq_table tmf)
{
switch (tmf) {
case TMR_ABORT_TASK: return "ABORT_TASK";
case TMR_ABORT_TASK_SET: return "ABORT_TASK_SET";
case TMR_CLEAR_ACA: return "CLEAR_ACA";
case TMR_CLEAR_TASK_SET: retur