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target_core_transport.c
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/*******************************************************************************
* Filename: target_core_transport.c
*
* This file contains the Generic Target Engine Core.
*
* Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
* Copyright (c) 2005, 2006, 2007 SBE, Inc.
* Copyright (c) 2007-2010 Rising Tide Systems
* Copyright (c) 2008-2010 Linux-iSCSI.org
*
* Nicholas A. Bellinger <[email protected]>
*
* 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/blkdev.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 <asm/unaligned.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_tcq.h>
#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>
#include <target/target_core_configfs.h>
#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_pr.h"
#include "target_core_ua.h"
static int sub_api_initialized;
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_tg_pt_gp_mem_cache;
static int transport_generic_write_pending(struct se_cmd *);
static int transport_processing_thread(void *param);
static int __transport_execute_tasks(struct se_device *dev, struct se_cmd *);
static void transport_complete_task_attr(struct se_cmd *cmd);
static void transport_handle_queue_full(struct se_cmd *cmd,
struct se_device *dev);
static void transport_free_dev_tasks(struct se_cmd *cmd);
static int transport_generic_get_mem(struct se_cmd *cmd);
static void transport_put_cmd(struct se_cmd *cmd);
static void transport_remove_cmd_from_queue(struct se_cmd *cmd);
static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
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_tg_pt_gp_mem_cache = kmem_cache_create(
"t10_alua_tg_pt_gp_mem_cache",
sizeof(struct t10_alua_tg_pt_gp_member),
__alignof__(struct t10_alua_tg_pt_gp_member),
0, NULL);
if (!t10_alua_tg_pt_gp_mem_cache) {
pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
"mem_t failed\n");
goto out_free_tg_pt_gp_cache;
}
target_completion_wq = alloc_workqueue("target_completion",
WQ_MEM_RECLAIM, 0);
if (!target_completion_wq)
goto out_free_tg_pt_gp_mem_cache;
return 0;
out_free_tg_pt_gp_mem_cache:
kmem_cache_destroy(t10_alua_tg_pt_gp_mem_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_tg_pt_gp_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;
}
static void transport_init_queue_obj(struct se_queue_obj *qobj)
{
atomic_set(&qobj->queue_cnt, 0);
INIT_LIST_HEAD(&qobj->qobj_list);
init_waitqueue_head(&qobj->thread_wq);
spin_lock_init(&qobj->cmd_queue_lock);
}
void transport_subsystem_check_init(void)
{
int ret;
if (sub_api_initialized)
return;
ret = request_module("target_core_iblock");
if (ret != 0)
pr_err("Unable to load target_core_iblock\n");
ret = request_module("target_core_file");
if (ret != 0)
pr_err("Unable to load target_core_file\n");
ret = request_module("target_core_pscsi");
if (ret != 0)
pr_err("Unable to load target_core_pscsi\n");
ret = request_module("target_core_stgt");
if (ret != 0)
pr_err("Unable to load target_core_stgt\n");
sub_api_initialized = 1;
return;
}
struct se_session *transport_init_session(void)
{
struct se_session *se_sess;
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);
}
INIT_LIST_HEAD(&se_sess->sess_list);
INIT_LIST_HEAD(&se_sess->sess_acl_list);
INIT_LIST_HEAD(&se_sess->sess_cmd_list);
INIT_LIST_HEAD(&se_sess->sess_wait_list);
spin_lock_init(&se_sess->sess_cmd_lock);
kref_init(&se_sess->sess_kref);
return se_sess;
}
EXPORT_SYMBOL(transport_init_session);
/*
* 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)
{
unsigned char buf[PR_REG_ISID_LEN];
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) {
/*
* 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]);
}
kref_get(&se_nacl->acl_kref);
spin_lock_irq(&se_nacl->nacl_sess_lock);
/*
* 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_irq(&se_nacl->nacl_sess_lock);
}
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->get_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);
static void target_release_session(struct kref *kref)
{
struct se_session *se_sess = container_of(kref,
struct se_session, sess_kref);
struct se_portal_group *se_tpg = se_sess->se_tpg;
se_tpg->se_tpg_tfo->close_session(se_sess);
}
void target_get_session(struct se_session *se_sess)
{
kref_get(&se_sess->sess_kref);
}
EXPORT_SYMBOL(target_get_session);
int target_put_session(struct se_session *se_sess)
{
return kref_put(&se_sess->sess_kref, target_release_session);
}
EXPORT_SYMBOL(target_put_session);
static void target_complete_nacl(struct kref *kref)
{
struct se_node_acl *nacl = container_of(kref,
struct se_node_acl, acl_kref);
complete(&nacl->acl_free_comp);
}
void target_put_nacl(struct se_node_acl *nacl)
{
kref_put(&nacl->acl_kref, target_complete_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 (se_nacl->acl_stop == 0)
list_del(&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)
{
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;
struct target_core_fabric_ops *se_tfo;
struct se_node_acl *se_nacl;
unsigned long flags;
bool comp_nacl = true;
if (!se_tpg) {
transport_free_session(se_sess);
return;
}
se_tfo = se_tpg->se_tpg_tfo;
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);
/*
* Determine if we need to do extra work for this initiator node's
* struct se_node_acl if it had been previously dynamically generated.
*/
se_nacl = se_sess->se_node_acl;
spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
if (se_nacl && se_nacl->dynamic_node_acl) {
if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
list_del(&se_nacl->acl_list);
se_tpg->num_node_acls--;
spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
core_tpg_wait_for_nacl_pr_ref(se_nacl);
core_free_device_list_for_node(se_nacl, se_tpg);
se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
comp_nacl = false;
spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
}
}
spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
se_tpg->se_tpg_tfo->get_fabric_name());
/*
* If last kref is dropping now for an explict NodeACL, awake sleeping
* ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
* removal context.
*/
if (se_nacl && comp_nacl == true)
target_put_nacl(se_nacl);
transport_free_session(se_sess);
}
EXPORT_SYMBOL(transport_deregister_session);
/*
* Called with cmd->t_state_lock held.
*/
static void transport_all_task_dev_remove_state(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_task *task;
unsigned long flags;
if (!dev)
return;
list_for_each_entry(task, &cmd->t_task_list, t_list) {
if (task->task_flags & TF_ACTIVE)
continue;
spin_lock_irqsave(&dev->execute_task_lock, flags);
if (task->t_state_active) {
pr_debug("Removed ITT: 0x%08x dev: %p task[%p]\n",
cmd->se_tfo->get_task_tag(cmd), dev, task);
list_del(&task->t_state_list);
atomic_dec(&cmd->t_task_cdbs_ex_left);
task->t_state_active = false;
}
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
}
/* transport_cmd_check_stop():
*
* 'transport_off = 1' determines if CMD_T_ACTIVE should be cleared.
* 'transport_off = 2' determines if task_dev_state should be removed.
*
* A non-zero u8 t_state sets cmd->t_state.
* Returns 1 when command is stopped, else 0.
*/
static int transport_cmd_check_stop(
struct se_cmd *cmd,
int transport_off,
u8 t_state)
{
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
/*
* Determine if IOCTL context caller in requesting the stopping of this
* command for LUN shutdown purposes.
*/
if (cmd->transport_state & CMD_T_LUN_STOP) {
pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
cmd->transport_state &= ~CMD_T_ACTIVE;
if (transport_off == 2)
transport_all_task_dev_remove_state(cmd);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete(&cmd->transport_lun_stop_comp);
return 1;
}
/*
* 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%08x\n",
__func__, __LINE__,
cmd->se_tfo->get_task_tag(cmd));
if (transport_off == 2)
transport_all_task_dev_remove_state(cmd);
/*
* Clear struct se_cmd->se_lun before the transport_off == 2 handoff
* to FE.
*/
if (transport_off == 2)
cmd->se_lun = NULL;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete(&cmd->t_transport_stop_comp);
return 1;
}
if (transport_off) {
cmd->transport_state &= ~CMD_T_ACTIVE;
if (transport_off == 2) {
transport_all_task_dev_remove_state(cmd);
/*
* Clear struct se_cmd->se_lun before the transport_off == 2
* handoff to fabric module.
*/
cmd->se_lun = NULL;
/*
* Some fabric modules like tcm_loop can release
* their internally allocated I/O reference now 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.
*/
if (cmd->se_tfo->check_stop_free != NULL) {
spin_unlock_irqrestore(
&cmd->t_state_lock, flags);
return cmd->se_tfo->check_stop_free(cmd);
}
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return 0;
} else if (t_state)
cmd->t_state = t_state;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return 0;
}
static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
{
return transport_cmd_check_stop(cmd, 2, 0);
}
static void transport_lun_remove_cmd(struct se_cmd *cmd)
{
struct se_lun *lun = cmd->se_lun;
unsigned long flags;
if (!lun)
return;
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
transport_all_task_dev_remove_state(cmd);
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
spin_lock_irqsave(&lun->lun_cmd_lock, flags);
if (!list_empty(&cmd->se_lun_node))
list_del_init(&cmd->se_lun_node);
spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
}
void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
{
if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
transport_lun_remove_cmd(cmd);
if (transport_cmd_check_stop_to_fabric(cmd))
return;
if (remove) {
transport_remove_cmd_from_queue(cmd);
transport_put_cmd(cmd);
}
}
static void transport_add_cmd_to_queue(struct se_cmd *cmd, int t_state,
bool at_head)
{
struct se_device *dev = cmd->se_dev;
struct se_queue_obj *qobj = &dev->dev_queue_obj;
unsigned long flags;
if (t_state) {
spin_lock_irqsave(&cmd->t_state_lock, flags);
cmd->t_state = t_state;
cmd->transport_state |= CMD_T_ACTIVE;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
/* If the cmd is already on the list, remove it before we add it */
if (!list_empty(&cmd->se_queue_node))
list_del(&cmd->se_queue_node);
else
atomic_inc(&qobj->queue_cnt);
if (at_head)
list_add(&cmd->se_queue_node, &qobj->qobj_list);
else
list_add_tail(&cmd->se_queue_node, &qobj->qobj_list);
cmd->transport_state |= CMD_T_QUEUED;
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
wake_up_interruptible(&qobj->thread_wq);
}
static struct se_cmd *
transport_get_cmd_from_queue(struct se_queue_obj *qobj)
{
struct se_cmd *cmd;
unsigned long flags;
spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
if (list_empty(&qobj->qobj_list)) {
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
return NULL;
}
cmd = list_first_entry(&qobj->qobj_list, struct se_cmd, se_queue_node);
cmd->transport_state &= ~CMD_T_QUEUED;
list_del_init(&cmd->se_queue_node);
atomic_dec(&qobj->queue_cnt);
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
return cmd;
}
static void transport_remove_cmd_from_queue(struct se_cmd *cmd)
{
struct se_queue_obj *qobj = &cmd->se_dev->dev_queue_obj;
unsigned long flags;
spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
if (!(cmd->transport_state & CMD_T_QUEUED)) {
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
return;
}
cmd->transport_state &= ~CMD_T_QUEUED;
atomic_dec(&qobj->queue_cnt);
list_del_init(&cmd->se_queue_node);
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
}
/*
* Completion function used by TCM subsystem plugins (such as FILEIO)
* for queueing up response from struct se_subsystem_api->do_task()
*/
void transport_complete_sync_cache(struct se_cmd *cmd, int good)
{
struct se_task *task = list_entry(cmd->t_task_list.next,
struct se_task, t_list);
if (good) {
cmd->scsi_status = SAM_STAT_GOOD;
task->task_scsi_status = GOOD;
} else {
task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
task->task_se_cmd->scsi_sense_reason =
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
transport_complete_task(task, good);
}
EXPORT_SYMBOL(transport_complete_sync_cache);
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);
}
/* transport_complete_task():
*
* Called from interrupt and non interrupt context depending
* on the transport plugin.
*/
void transport_complete_task(struct se_task *task, int success)
{
struct se_cmd *cmd = task->task_se_cmd;
struct se_device *dev = cmd->se_dev;
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
task->task_flags &= ~TF_ACTIVE;
/*
* See if any sense data exists, if so set the TASK_SENSE flag.
* Also check for any other post completion work that needs to be
* done by the plugins.
*/
if (dev && dev->transport->transport_complete) {
if (dev->transport->transport_complete(task) != 0) {
cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
task->task_flags |= TF_HAS_SENSE;
success = 1;
}
}
/*
* See if we are waiting for outstanding struct se_task
* to complete for an exception condition
*/
if (task->task_flags & TF_REQUEST_STOP) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete(&task->task_stop_comp);
return;
}
if (!success)
cmd->transport_state |= CMD_T_FAILED;
/*
* Decrement the outstanding t_task_cdbs_left count. The last
* struct se_task from struct se_cmd will complete itself into the
* device queue depending upon int success.
*/
if (!atomic_dec_and_test(&cmd->t_task_cdbs_left)) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return;
}
/*
* Check for case where an explict ABORT_TASK has been received
* and transport_wait_for_tasks() will be waiting for completion..
*/
if (cmd->transport_state & CMD_T_ABORTED &&
cmd->transport_state & CMD_T_STOP) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
complete(&cmd->t_transport_stop_comp);
return;
} else if (cmd->transport_state & CMD_T_FAILED) {
cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
INIT_WORK(&cmd->work, target_complete_failure_work);
} else {
INIT_WORK(&cmd->work, target_complete_ok_work);
}
cmd->t_state = TRANSPORT_COMPLETE;
cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
queue_work(target_completion_wq, &cmd->work);
}
EXPORT_SYMBOL(transport_complete_task);
/*
* Called by transport_add_tasks_from_cmd() once a struct se_cmd's
* struct se_task list are ready to be added to the active execution list
* struct se_device
* Called with se_dev_t->execute_task_lock called.
*/
static inline int transport_add_task_check_sam_attr(
struct se_task *task,
struct se_task *task_prev,
struct se_device *dev)
{
/*
* No SAM Task attribute emulation enabled, add to tail of
* execution queue
*/
if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED) {
list_add_tail(&task->t_execute_list, &dev->execute_task_list);
return 0;
}
/*
* HEAD_OF_QUEUE attribute for received CDB, which means
* the first task that is associated with a struct se_cmd goes to
* head of the struct se_device->execute_task_list, and task_prev
* after that for each subsequent task
*/
if (task->task_se_cmd->sam_task_attr == MSG_HEAD_TAG) {
list_add(&task->t_execute_list,
(task_prev != NULL) ?
&task_prev->t_execute_list :
&dev->execute_task_list);
pr_debug("Set HEAD_OF_QUEUE for task CDB: 0x%02x"
" in execution queue\n",
task->task_se_cmd->t_task_cdb[0]);
return 1;
}
/*
* For ORDERED, SIMPLE or UNTAGGED attribute tasks once they have been
* transitioned from Dermant -> Active state, and are added to the end
* of the struct se_device->execute_task_list
*/
list_add_tail(&task->t_execute_list, &dev->execute_task_list);
return 0;
}
/* __transport_add_task_to_execute_queue():
*
* Called with se_dev_t->execute_task_lock called.
*/
static void __transport_add_task_to_execute_queue(
struct se_task *task,
struct se_task *task_prev,
struct se_device *dev)
{
int head_of_queue;
head_of_queue = transport_add_task_check_sam_attr(task, task_prev, dev);
atomic_inc(&dev->execute_tasks);
if (task->t_state_active)
return;
/*
* Determine if this task needs to go to HEAD_OF_QUEUE for the
* state list as well. Running with SAM Task Attribute emulation
* will always return head_of_queue == 0 here
*/
if (head_of_queue)
list_add(&task->t_state_list, (task_prev) ?
&task_prev->t_state_list :
&dev->state_task_list);
else
list_add_tail(&task->t_state_list, &dev->state_task_list);
task->t_state_active = true;
pr_debug("Added ITT: 0x%08x task[%p] to dev: %p\n",
task->task_se_cmd->se_tfo->get_task_tag(task->task_se_cmd),
task, dev);
}
static void transport_add_tasks_to_state_queue(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_task *task;
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
list_for_each_entry(task, &cmd->t_task_list, t_list) {
spin_lock(&dev->execute_task_lock);
if (!task->t_state_active) {
list_add_tail(&task->t_state_list,
&dev->state_task_list);
task->t_state_active = true;
pr_debug("Added ITT: 0x%08x task[%p] to dev: %p\n",
task->task_se_cmd->se_tfo->get_task_tag(
task->task_se_cmd), task, dev);
}
spin_unlock(&dev->execute_task_lock);
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
static void __transport_add_tasks_from_cmd(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_task *task, *task_prev = NULL;
list_for_each_entry(task, &cmd->t_task_list, t_list) {
if (!list_empty(&task->t_execute_list))
continue;
/*
* __transport_add_task_to_execute_queue() handles the
* SAM Task Attribute emulation if enabled
*/
__transport_add_task_to_execute_queue(task, task_prev, dev);
task_prev = task;
}
}
static void transport_add_tasks_from_cmd(struct se_cmd *cmd)
{
unsigned long flags;
struct se_device *dev = cmd->se_dev;
spin_lock_irqsave(&dev->execute_task_lock, flags);
__transport_add_tasks_from_cmd(cmd);
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
void __transport_remove_task_from_execute_queue(struct se_task *task,
struct se_device *dev)
{
list_del_init(&task->t_execute_list);
atomic_dec(&dev->execute_tasks);
}
static void transport_remove_task_from_execute_queue(
struct se_task *task,
struct se_device *dev)
{
unsigned long flags;
if (WARN_ON(list_empty(&task->t_execute_list)))
return;
spin_lock_irqsave(&dev->execute_task_lock, flags);
__transport_remove_task_from_execute_queue(task, dev);
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}
/*
* Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
*/
static 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(&dev->dev_qf_count);
smp_mb__after_atomic_dec();
pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
: "UNKNOWN");
transport_add_cmd_to_queue(cmd, cmd->t_state, true);
}
}
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: ");
switch (dev->dev_status) {
case TRANSPORT_DEVICE_ACTIVATED:
*bl += sprintf(b + *bl, "ACTIVATED");
break;
case TRANSPORT_DEVICE_DEACTIVATED:
*bl += sprintf(b + *bl, "DEACTIVATED");
break;
case TRANSPORT_DEVICE_SHUTDOWN:
*bl += sprintf(b + *bl, "SHUTDOWN");
break;
case TRANSPORT_DEVICE_OFFLINE_ACTIVATED:
case TRANSPORT_DEVICE_OFFLINE_DEACTIVATED:
*bl += sprintf(b + *bl, "OFFLINE");
break;
default:
*bl += sprintf(b + *bl, "UNKNOWN=%d", dev->dev_status);
break;
}
*bl += sprintf(b + *bl, " Execute/Max Queue Depth: %d/%d",