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linux/drivers/target/target_core_transport.c
Bart Van Assche aa73237dcb scsi: target/core: Always call transport_complete_callback() upon failure 
COMPARE AND WRITE command execution starts with a call of
sbc_compare_and_write(). That function locks the caw_sem member in the
backend device data structure and submits a read request to the backend
driver. Upon successful completion of the read compare_and_write_callback()
gets called. That last function compares the data that has been read. If it
matches transport_complete_callback is set to compare_and_write_post and a
write request is submitted. compare_and_write_post() submits a write request
to the backend driver.

XDWRITEREAD command execution starts with sbc_execute_rw() submitting a
read to the backend device. Upon successful completion of the read the
xdreadwrite_callback() gets called. That function xors the data that has
been read with the data in the data-out buffer and stores the result in
the data-in buffer.

Call transport_complete_callback() not only if COMPARE AND WRITE fails but
also if XDWRITEREAD fails. This makes the code more systematic. Make sure
that the callback functions handle (cmd, false, NULL) argument triples fine.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-16 01:13:35 -04:00

3451 lines
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/*******************************************************************************
* 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 = 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_user");
if (ret != 0)
pr_err("Unable to load target_core_user\n");
sub_api_initialized = 1;
}
/**
* transport_init_session - initialize a session object
* @se_sess: Session object pointer.
*
* The caller must have zero-initialized @se_sess before calling this function.
*/
void 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);
}
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;
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);
}
transport_init_session(se_sess);
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 = kcalloc(tag_size, tag_num,
GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
if (!se_sess->sess_cmd_map) {
se_sess->sess_cmd_map = vzalloc(array_size(tag_size, tag_num));
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->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);
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);
}
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->get_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);
/*
* Clear struct se_cmd->se_lun before the handoff to FE.
*/
cmd->se_lun = NULL;
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 transport_lun_remove_cmd(struct se_cmd *cmd)
{
struct se_lun *lun = cmd->se_lun;
if (!lun)
return;
if (cmpxchg(&cmd->lun_ref_active, true, false))
percpu_ref_put(&lun->lun_ref);
}
int transport_cmd_finish_abort(struct se_cmd *cmd)
{
bool send_tas = cmd->transport_state & CMD_T_TAS;
bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
int ret = 0;
if (send_tas)
transport_send_task_abort(cmd);
if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
transport_lun_remove_cmd(cmd);
/*
* Allow the fabric driver to unmap any resources before
* releasing the descriptor via TFO->release_cmd()
*/
if (!send_tas)
cmd->se_tfo->aborted_task(cmd);
if (transport_cmd_check_stop_to_fabric(cmd))
return 1;
if (!send_tas && ack_kref)
ret = target_put_sess_cmd(cmd);
return ret;
}
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);
void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
{
struct se_device *dev = cmd->se_dev;
int success;
unsigned long flags;
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;
}
/*
* Check for case where an explicit 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);
/*
* If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
* release se_device->caw_sem obtained by sbc_compare_and_write()
* since target_complete_ok_work() or target_complete_failure_work()
* won't be called to invoke the normal CAW completion callbacks.
*/
if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
up(&dev->caw_sem);
}
complete_all(&cmd->t_transport_stop_comp);
return;
} else if (!success) {
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);
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->get_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->get_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->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->get_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_lun_remove_cmd(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;
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, NULL);
if (transport_check_aborted_status(cmd, 1))
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_lun_remove_cmd(cmd);
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;
}
static int __transport_check_aborted_status(struct se_cmd *, int);
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.
*/
spin_lock_irq(&cmd->t_state_lock);
if (__transport_check_aborted_status(cmd, 1)) {
spin_unlock_irq(&cmd->t_state_lock);
return;
}
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_irq(&cmd->t_state_lock);
complete_all(&cmd->t_transport_stop_comp);
return;
}
cmd->t_state = TRANSPORT_PROCESSING;
cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
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_lun_remove_cmd(cmd);
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_lun_remove_cmd(cmd);
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_lun_remove_cmd(cmd);
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_lun_remove_cmd(cmd);
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_lun_remove_cmd(cmd);
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) {
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);
}
/*
* This function is called by frontend drivers after processing of a command
* has finished.
*
* The protocol for ensuring that either the regular flow or the TMF
* code drops one reference is as follows:
* - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
* the frontend driver to drop one reference, synchronously or asynchronously.
* - 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. transport_cmd_finish_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 (cmd->se_lun)
transport_lun_remove_cmd(cmd);
}
if (aborted)
cmd->compl = &compl;
if (!aborted || tas)
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;
}
se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
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 *compl = se_cmd->compl;
unsigned long flags;
if (se_sess) {
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
list_del_init(&se_cmd->se_cmd_list);
if (se_sess->sess_tearing_down && list_empty(&se_sess->sess_cmd_list))
wake_up(&se_sess->cmd_list_wq);
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
}
target_free_cmd_mem(se_cmd);
se_cmd->se_tfo->release_cmd(se_cmd);
if (compl)
complete(compl);
}
/**
* 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: return "CLEAR_TASK_SET";
case TMR_LUN_RESET: return "LUN_RESET";
case TMR_TARGET_WARM_RESET: return "TARGET_WARM_RESET";
case TMR_TARGET_COLD_RESET: return "TARGET_COLD_RESET";
case TMR_UNKNOWN: break;
}
return "(?)";
}
void target_show_cmd(const char *pfx, struct se_cmd *cmd)
{
char *ts_str = target_ts_to_str(cmd->transport_state);
const u8 *cdb = cmd->t_task_cdb;
struct se_tmr_req *tmf = cmd->se_tmr_req;
if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
pfx, cdb[0], cdb[1], cmd->tag,
data_dir_name(cmd->data_direction),
cmd->se_tfo->get_cmd_state(cmd),
cmd_state_name(cmd->t_state), cmd->data_length,
kref_read(&cmd->cmd_kref), ts_str);
} else {
pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
pfx, target_tmf_name(tmf->function), cmd->tag,
tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
cmd_state_name(cmd->t_state),
kref_read(&cmd->cmd_kref), ts_str);
}
kfree(ts_str);
}
EXPORT_SYMBOL(target_show_cmd);
/**
* target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
* @se_sess: session to flag
*/
void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
{
unsigned long flags;
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
se_sess->sess_tearing_down = 1;
spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
}
EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
/**
* target_wait_for_sess_cmds - Wait for outstanding commands
* @se_sess: session to wait for active I/O
*/
void target_wait_for_sess_cmds(struct se_session *se_sess)
{
struct se_cmd *cmd;
int ret;
WARN_ON_ONCE(!se_sess->sess_tearing_down);
spin_lock_irq(&se_sess->sess_cmd_lock);
do {
ret = wait_event_lock_irq_timeout(
se_sess->cmd_list_wq,
list_empty(&se_sess->sess_cmd_list),
se_sess->sess_cmd_lock, 180 * HZ);
list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
target_show_cmd("session shutdown: still waiting for ",
cmd);
} while (ret <= 0);
spin_unlock_irq(&se_sess->sess_cmd_lock);
}
EXPORT_SYMBOL(target_wait_for_sess_cmds);
static void target_lun_confirm(struct percpu_ref *ref)
{
struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
complete(&lun->lun_ref_comp);
}
void transport_clear_lun_ref(struct se_lun *lun)
{
/*
* Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
* the initial reference and schedule confirm kill to be
* executed after one full RCU grace period has completed.
*/
percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
/*
* The first completion waits for percpu_ref_switch_to_atomic_rcu()
* to call target_lun_confirm after lun->lun_ref has been marked
* as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
* mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
* fails for all new incoming I/O.
*/
wait_for_completion(&lun->lun_ref_comp);
/*
* The second completion waits for percpu_ref_put_many() to
* invoke ->release() after lun->lun_ref has switched to
* atomic_t mode, and lun->lun_ref.count has reached zero.
*
* At this point all target-core lun->lun_ref references have
* been dropped via transport_lun_remove_cmd(), and it's safe
* to proceed with the remaining LUN shutdown.
*/
wait_for_completion(&lun->lun_shutdown_comp);
}
static bool
__transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
bool *aborted, bool *tas, unsigned long *flags)
__releases(&cmd->t_state_lock)
__acquires(&cmd->t_state_lock)
{
assert_spin_locked(&cmd->t_state_lock);
WARN_ON_ONCE(!irqs_disabled());
if (fabric_stop)
cmd->transport_state |= CMD_T_FABRIC_STOP;
if (cmd->transport_state & CMD_T_ABORTED)
*aborted = true;
if (cmd->transport_state & CMD_T_TAS)
*tas = true;
if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
return false;
if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
return false;
if (!(cmd->transport_state & CMD_T_ACTIVE))
return false;
if (fabric_stop && *aborted)
return false;
cmd->transport_state |= CMD_T_STOP;
target_show_cmd("wait_for_tasks: Stopping ", cmd);
spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
180 * HZ))
target_show_cmd("wait for tasks: ", cmd);
spin_lock_irqsave(&cmd->t_state_lock, *flags);
cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
"t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
return true;
}
/**
* transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
* @cmd: command to wait on
*/
bool transport_wait_for_tasks(struct se_cmd *cmd)
{
unsigned long flags;
bool ret, aborted = false, tas = false;
spin_lock_irqsave(&cmd->t_state_lock, flags);
ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return ret;
}
EXPORT_SYMBOL(transport_wait_for_tasks);
struct sense_info {
u8 key;
u8 asc;
u8 ascq;
bool add_sector_info;
};
static const struct sense_info sense_info_table[] = {
[TCM_NO_SENSE] = {
.key = NOT_READY
},
[TCM_NON_EXISTENT_LUN] = {
.key = ILLEGAL_REQUEST,
.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
},
[TCM_UNSUPPORTED_SCSI_OPCODE] = {
.key = ILLEGAL_REQUEST,
.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
},
[TCM_SECTOR_COUNT_TOO_MANY] = {
.key = ILLEGAL_REQUEST,
.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
},
[TCM_UNKNOWN_MODE_PAGE] = {
.key = ILLEGAL_REQUEST,
.asc = 0x24, /* INVALID FIELD IN CDB */
},
[TCM_CHECK_CONDITION_ABORT_CMD] = {
.key = ABORTED_COMMAND,
.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
.ascq = 0x03,
},
[TCM_INCORRECT_AMOUNT_OF_DATA] = {
.key = ABORTED_COMMAND,
.asc = 0x0c, /* WRITE ERROR */
.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
},
[TCM_INVALID_CDB_FIELD] = {
.key = ILLEGAL_REQUEST,
.asc = 0x24, /* INVALID FIELD IN CDB */
},
[TCM_INVALID_PARAMETER_LIST] = {
.key = ILLEGAL_REQUEST,
.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
},
[TCM_TOO_MANY_TARGET_DESCS] = {
.key = ILLEGAL_REQUEST,
.asc = 0x26,
.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
},
[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
.key = ILLEGAL_REQUEST,
.asc = 0x26,
.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
},
[TCM_TOO_MANY_SEGMENT_DESCS] = {
.key = ILLEGAL_REQUEST,
.asc = 0x26,
.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
},
[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
.key = ILLEGAL_REQUEST,
.asc = 0x26,
.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
},
[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
.key = ILLEGAL_REQUEST,
.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
},
[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
.key = ILLEGAL_REQUEST,
.asc = 0x0c, /* WRITE ERROR */
.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
},
[TCM_SERVICE_CRC_ERROR] = {
.key = ABORTED_COMMAND,
.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
.ascq = 0x05, /* N/A */
},
[TCM_SNACK_REJECTED] = {
.key = ABORTED_COMMAND,
.asc = 0x11, /* READ ERROR */
.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
},
[TCM_WRITE_PROTECTED] = {
.key = DATA_PROTECT,
.asc = 0x27, /* WRITE PROTECTED */
},
[TCM_ADDRESS_OUT_OF_RANGE] = {
.key = ILLEGAL_REQUEST,
.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
},
[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
.key = UNIT_ATTENTION,
},
[TCM_CHECK_CONDITION_NOT_READY] = {
.key = NOT_READY,
},
[TCM_MISCOMPARE_VERIFY] = {
.key = MISCOMPARE,
.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
.ascq = 0x00,
},
[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
.key = ABORTED_COMMAND,
.asc = 0x10,
.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
.add_sector_info = true,
},
[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
.key = ABORTED_COMMAND,
.asc = 0x10,
.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
.add_sector_info = true,
},
[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
.key = ABORTED_COMMAND,
.asc = 0x10,
.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
.add_sector_info = true,
},
[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
.key = COPY_ABORTED,
.asc = 0x0d,
.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
},
[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
/*
* Returning ILLEGAL REQUEST would cause immediate IO errors on
* Solaris initiators. Returning NOT READY instead means the
* operations will be retried a finite number of times and we
* can survive intermittent errors.
*/
.key = NOT_READY,
.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
},
[TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
/*
* From spc4r22 section5.7.7,5.7.8
* If a PERSISTENT RESERVE OUT command with a REGISTER service action
* or a REGISTER AND IGNORE EXISTING KEY service action or
* REGISTER AND MOVE service actionis attempted,
* but there are insufficient device server resources to complete the
* operation, then the command shall be terminated with CHECK CONDITION
* status, with the sense key set to ILLEGAL REQUEST,and the additonal
* sense code set to INSUFFICIENT REGISTRATION RESOURCES.
*/
.key = ILLEGAL_REQUEST,
.asc = 0x55,
.ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
},
};
/**
* translate_sense_reason - translate a sense reason into T10 key, asc and ascq
* @cmd: SCSI command in which the resulting sense buffer or SCSI status will
* be stored.
* @reason: LIO sense reason code. If this argument has the value
* TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
* dequeuing a unit attention fails due to multiple commands being processed
* concurrently, set the command status to BUSY.
*
* Return: 0 upon success or -EINVAL if the sense buffer is too small.
*/
static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
{
const struct sense_info *si;
u8 *buffer = cmd->sense_buffer;
int r = (__force int)reason;
u8 key, asc, ascq;
bool desc_format = target_sense_desc_format(cmd->se_dev);
if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
si = &sense_info_table[r];
else
si = &sense_info_table[(__force int)
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
key = si->key;
if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
&ascq)) {
cmd->scsi_status = SAM_STAT_BUSY;
return;
}
} else if (si->asc == 0) {
WARN_ON_ONCE(cmd->scsi_asc == 0);
asc = cmd->scsi_asc;
ascq = cmd->scsi_ascq;
} else {
asc = si->asc;
ascq = si->ascq;
}
cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
if (si->add_sector_info)
WARN_ON_ONCE(scsi_set_sense_information(buffer,
cmd->scsi_sense_length,
cmd->bad_sector) < 0);
}
int
transport_send_check_condition_and_sense(struct se_cmd *cmd,
sense_reason_t reason, int from_transport)
{
unsigned long flags;
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return 0;
}
cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
if (!from_transport)
translate_sense_reason(cmd, reason);
trace_target_cmd_complete(cmd);
return cmd->se_tfo->queue_status(cmd);
}
EXPORT_SYMBOL(transport_send_check_condition_and_sense);
static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
__releases(&cmd->t_state_lock)
__acquires(&cmd->t_state_lock)
{
int ret;
assert_spin_locked(&cmd->t_state_lock);
WARN_ON_ONCE(!irqs_disabled());
if (!(cmd->transport_state & CMD_T_ABORTED))
return 0;
/*
* If cmd has been aborted but either no status is to be sent or it has
* already been sent, just return
*/
if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
if (send_status)
cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
return 1;
}
pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
" 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
cmd->scsi_status = SAM_STAT_TASK_ABORTED;
trace_target_cmd_complete(cmd);
spin_unlock_irq(&cmd->t_state_lock);
ret = cmd->se_tfo->queue_status(cmd);
if (ret)
transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
spin_lock_irq(&cmd->t_state_lock);
return 1;
}
int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
{
int ret;
spin_lock_irq(&cmd->t_state_lock);
ret = __transport_check_aborted_status(cmd, send_status);
spin_unlock_irq(&cmd->t_state_lock);
return ret;
}
EXPORT_SYMBOL(transport_check_aborted_status);
void transport_send_task_abort(struct se_cmd *cmd)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return;
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
/*
* If there are still expected incoming fabric WRITEs, we wait
* until until they have completed before sending a TASK_ABORTED
* response. This response with TASK_ABORTED status will be
* queued back to fabric module by transport_check_aborted_status().
*/
if (cmd->data_direction == DMA_TO_DEVICE) {
if (cmd->se_tfo->write_pending_status(cmd) != 0) {
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
goto send_abort;
}
cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
return;
}
}
send_abort:
cmd->scsi_status = SAM_STAT_TASK_ABORTED;
transport_lun_remove_cmd(cmd);
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);
}
static void target_tmr_work(struct work_struct *work)
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
struct se_device *dev = cmd->se_dev;
struct se_tmr_req *tmr = cmd->se_tmr_req;
unsigned long flags;
int ret;
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->transport_state & CMD_T_ABORTED) {
tmr->response = TMR_FUNCTION_REJECTED;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
goto check_stop;
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
switch (tmr->function) {
case TMR_ABORT_TASK:
core_tmr_abort_task(dev, tmr, cmd->se_sess);
break;
case TMR_ABORT_TASK_SET:
case TMR_CLEAR_ACA:
case TMR_CLEAR_TASK_SET:
tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
break;
case TMR_LUN_RESET:
ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
TMR_FUNCTION_REJECTED;
if (tmr->response == TMR_FUNCTION_COMPLETE) {
target_ua_allocate_lun(cmd->se_sess->se_node_acl,
cmd->orig_fe_lun, 0x29,
ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
}
break;
case TMR_TARGET_WARM_RESET:
tmr->response = TMR_FUNCTION_REJECTED;
break;
case TMR_TARGET_COLD_RESET:
tmr->response = TMR_FUNCTION_REJECTED;
break;
default:
pr_err("Unknown TMR function: 0x%02x.\n",
tmr->function);
tmr->response = TMR_FUNCTION_REJECTED;
break;
}
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->transport_state & CMD_T_ABORTED) {
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
goto check_stop;
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
cmd->se_tfo->queue_tm_rsp(cmd);
check_stop:
transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
}
int transport_generic_handle_tmr(
struct se_cmd *cmd)
{
unsigned long flags;
bool aborted = false;
spin_lock_irqsave(&cmd->t_state_lock, flags);
if (cmd->transport_state & CMD_T_ABORTED) {
aborted = true;
} else {
cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
cmd->transport_state |= CMD_T_ACTIVE;
}
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
if (aborted) {
pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
"ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
cmd->se_tmr_req->ref_task_tag, cmd->tag);
transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return 0;
}
INIT_WORK(&cmd->work, target_tmr_work);
queue_work(cmd->se_dev->tmr_wq, &cmd->work);
return 0;
}
EXPORT_SYMBOL(transport_generic_handle_tmr);
bool
target_check_wce(struct se_device *dev)
{
bool wce = false;
if (dev->transport->get_write_cache)
wce = dev->transport->get_write_cache(dev);
else if (dev->dev_attrib.emulate_write_cache > 0)
wce = true;
return wce;
}
bool
target_check_fua(struct se_device *dev)
{
return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
}
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