- 根目录:
- drivers
- target
- target_core_tmr.c
/*******************************************************************************
* Filename: target_core_tmr.c
*
* This file contains SPC-3 task management infrastructure
*
* Copyright (c) 2009,2010 Rising Tide Systems
* Copyright (c) 2009,2010 Linux-iSCSI.org
*
* 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/version.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <target/target_core_base.h>
#include <target/target_core_device.h>
#include <target/target_core_tmr.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>
#include <target/target_core_configfs.h>
#include "target_core_alua.h"
#include "target_core_pr.h"
#define DEBUG_LUN_RESET
#ifdef DEBUG_LUN_RESET
#define DEBUG_LR(x...) printk(KERN_INFO x)
#else
#define DEBUG_LR(x...)
#endif
struct se_tmr_req *core_tmr_alloc_req(
struct se_cmd *se_cmd,
void *fabric_tmr_ptr,
u8 function)
{
struct se_tmr_req *tmr;
tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
GFP_ATOMIC : GFP_KERNEL);
if (!(tmr)) {
printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
return ERR_PTR(-ENOMEM);
}
tmr->task_cmd = se_cmd;
tmr->fabric_tmr_ptr = fabric_tmr_ptr;
tmr->function = function;
INIT_LIST_HEAD(&tmr->tmr_list);
return tmr;
}
EXPORT_SYMBOL(core_tmr_alloc_req);
void core_tmr_release_req(
struct se_tmr_req *tmr)
{
struct se_device *dev = tmr->tmr_dev;
if (!dev) {
kmem_cache_free(se_tmr_req_cache, tmr);
return;
}
spin_lock(&dev->se_tmr_lock);
list_del(&tmr->tmr_list);
spin_unlock(&dev->se_tmr_lock);
kmem_cache_free(se_tmr_req_cache, tmr);
}
static void core_tmr_handle_tas_abort(
struct se_node_acl *tmr_nacl,
struct se_cmd *cmd,
int tas,
int fe_count)
{
if (!(fe_count)) {
transport_cmd_finish_abort(cmd, 1);
return;
}
/*
* TASK ABORTED status (TAS) bit support
*/
if (((tmr_nacl != NULL) &&
(tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
transport_send_task_abort(cmd);
transport_cmd_finish_abort(cmd, 0);
}
int core_tmr_lun_reset(
struct se_device *dev,
struct se_tmr_req *tmr,
struct list_head *preempt_and_abort_list,
struct se_cmd *prout_cmd)
{
struct se_cmd *cmd;
struct se_queue_req *qr, *qr_tmp;
struct se_node_acl *tmr_nacl = NULL;
struct se_portal_group *tmr_tpg = NULL;
struct se_queue_obj *qobj = dev->dev_queue_obj;
struct se_tmr_req *tmr_p, *tmr_pp;
struct se_task *task, *task_tmp;
unsigned long flags;
int fe_count, state, tas;
/*
* TASK_ABORTED status bit, this is configurable via ConfigFS
* struct se_device attributes. spc4r17 section 7.4.6 Control mode page
*
* A task aborted status (TAS) bit set to zero specifies that aborted
* tasks shall be terminated by the device server without any response
* to the application client. A TAS bit set to one specifies that tasks
* aborted by the actions of an I_T nexus other than the I_T nexus on
* which the command was received shall be completed with TASK ABORTED
* status (see SAM-4).
*/
tas = DEV_ATTRIB(dev)->emulate_tas;
/*
* Determine if this se_tmr is coming from a $FABRIC_MOD
* or struct se_device passthrough..
*/
if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
if (tmr_nacl && tmr_tpg) {
DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
" initiator port %s\n",
TPG_TFO(tmr_tpg)->get_fabric_name(),
tmr_nacl->initiatorname);
}
}
DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
(preempt_and_abort_list) ? "Preempt" : "TMR",
TRANSPORT(dev)->name, tas);
/*
* Release all pending and outgoing TMRs aside from the received
* LUN_RESET tmr..
*/
spin_lock(&dev->se_tmr_lock);
list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
/*
* Allow the received TMR to return with FUNCTION_COMPLETE.
*/
if (tmr && (tmr_p == tmr))
continue;
cmd = tmr_p->task_cmd;
if (!(cmd)) {
printk(KERN_ERR "Unable to locate struct se_cmd for TMR\n");
continue;
}
/*
* If this function was called with a valid pr_res_key
* parameter (eg: for PROUT PREEMPT_AND_ABORT service action
* skip non regisration key matching TMRs.
*/
if ((preempt_and_abort_list != NULL) &&
(core_scsi3_check_cdb_abort_and_preempt(
preempt_and_abort_list, cmd) != 0))
continue;
spin_unlock(&dev->se_tmr_lock);
spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
spin_lock(&dev->se_tmr_lock);
continue;
}
if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
spin_lock(&dev->se_tmr_lock);
continue;
}
DEBUG_LR("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
" Response: 0x%02x, t_state: %d\n",
(preempt_and_abort_list) ? "Preempt" : "", tmr_p,
tmr_p->function, tmr_p->response, cmd->t_state);
spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
transport_cmd_finish_abort_tmr(cmd);
spin_lock(&dev->se_tmr_lock);
}
spin_unlock(&dev->se_tmr_lock);
/*
* Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.
* This is following sam4r17, section 5.6 Aborting commands, Table 38
* for TMR LUN_RESET:
*
* a) "Yes" indicates that each command that is aborted on an I_T nexus
* other than the one that caused the SCSI device condition is
* completed with TASK ABORTED status, if the TAS bit is set to one in
* the Control mode page (see SPC-4). "No" indicates that no status is
* returned for aborted commands.
*
* d) If the logical unit reset is caused by a particular I_T nexus
* (e.g., by a LOGICAL UNIT RESET task management function), then "yes"
* (TASK_ABORTED status) applies.
*
* Otherwise (e.g., if triggered by a hard reset), "no"
* (no TASK_ABORTED SAM status) applies.
*
* Note that this seems to be independent of TAS (Task Aborted Status)
* in the Control Mode Page.
*/
spin_lock_irqsave(&dev->execute_task_lock, flags);
list_for_each_entry_safe(task, task_tmp, &dev->state_task_list,
t_state_list) {
if (!(TASK_CMD(task))) {
printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
continue;
}
cmd = TASK_CMD(task);
if (!T_TASK(cmd)) {
printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
" %p ITT: 0x%08x\n", task, cmd,
CMD_TFO(cmd)->get_task_tag(cmd));
continue;
}
/*
* For PREEMPT_AND_ABORT usage, only process commands
* with a matching reservation key.
*/
if ((preempt_and_abort_list != NULL) &&
(core_scsi3_check_cdb_abort_and_preempt(
preempt_and_abort_list, cmd) != 0))
continue;
/*
* Not aborting PROUT PREEMPT_AND_ABORT CDB..
*/
if (prout_cmd == cmd)
continue;
list_del(&task->t_state_list);
atomic_set(&task->task_state_active, 0);
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
"def_t_state: %d/%d cdb: 0x%02x\n",
(preempt_and_abort_list) ? "Preempt" : "", cmd, task,
CMD_TFO(cmd)->get_task_tag(cmd), 0,
CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
" t_task_cdbs: %d t_task_cdbs_left: %d"
" t_task_cdbs_sent: %d -- t_transport_active: %d"
" t_transport_stop: %d t_transport_sent: %d\n",
CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
T_TASK(cmd)->t_task_cdbs,
atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
atomic_read(&T_TASK(cmd)->t_transport_active),
atomic_read(&T_TASK(cmd)->t_transport_stop),
atomic_read(&T_TASK(cmd)->t_transport_sent));
if (atomic_read(&task->task_active)) {
atomic_set(&task->task_stop, 1);
spin_unlock_irqrestore(
&T_TASK(cmd)->t_state_lock, flags);
DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
" for dev: %p\n", task, dev);
wait_for_completion(&task->task_stop_comp);
DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
" dev: %p\n", task, dev);
spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
atomic_set(&task->task_active, 0);
atomic_set(&task->task_stop, 0);
} else {
if (atomic_read(&task->task_execute_queue) != 0)
transport_remove_task_from_execute_queue(task, dev);
}
__transport_stop_task_timer(task, &flags);
if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
spin_unlock_irqrestore(
&T_TASK(cmd)->t_state_lock, flags);
DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
" t_task_cdbs_ex_left: %d\n", task, dev,
atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
spin_lock_irqsave(&dev->execute_task_lock, flags);
continue;
}
fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
" task: %p, t_fe_count: %d dev: %p\n", task,
fe_count, dev);
atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
flags);
core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
spin_lock_irqsave(&dev->execute_task_lock, flags);
continue;
}
DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
" t_fe_count: %d dev: %p\n", task, fe_count, dev);
atomic_set(&T_TASK(cmd)->t_transport_aborted, 1);
spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
spin_lock_irqsave(&dev->execute_task_lock, flags);
}
spin_unlock_irqrestore(&dev->execute_task_lock, flags);
/*
* Release all commands remaining in the struct se_device cmd queue.
*
* This follows the same logic as above for the struct se_device
* struct se_task state list, where commands are returned with
* TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
* reference, otherwise the struct se_cmd is released.
*/
spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
cmd = (struct se_cmd *)qr->cmd;
if (!(cmd)) {
/*
* Skip these for non PREEMPT_AND_ABORT usage..
*/
if (preempt_and_abort_list != NULL)
continue;
atomic_dec(&qobj->queue_cnt);
list_del(&qr->qr_list);
kfree(qr);
continue;
}
/*
* For PREEMPT_AND_ABORT usage, only process commands
* with a matching reservation key.
*/
if ((preempt_and_abort_list != NULL) &&
(core_scsi3_check_cdb_abort_and_preempt(
preempt_and_abort_list, cmd) != 0))
continue;
/*
* Not aborting PROUT PREEMPT_AND_ABORT CDB..
*/
if (prout_cmd == cmd)
continue;
atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
atomic_dec(&qobj->queue_cnt);
list_del(&qr->qr_list);
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
state = qr->state;
kfree(qr);
DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
" %d t_fe_count: %d\n", (preempt_and_abort_list) ?
"Preempt" : "", cmd, state,
atomic_read(&T_TASK(cmd)->t_fe_count));
/*
* Signal that the command has failed via cmd->se_cmd_flags,
* and call TFO->new_cmd_failure() to wakeup any fabric
* dependent code used to wait for unsolicited data out
* allocation to complete. The fabric module is expected
* to dump any remaining unsolicited data out for the aborted
* command at this point.
*/
transport_new_cmd_failure(cmd);
core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
atomic_read(&T_TASK(cmd)->t_fe_count));
spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
}
spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
/*
* Clear any legacy SPC-2 reservation when called during
* LOGICAL UNIT RESET
*/
if (!(preempt_and_abort_list) &&
(dev->dev_flags & DF_SPC2_RESERVATIONS)) {
spin_lock(&dev->dev_reservation_lock);
dev->dev_reserved_node_acl = NULL;
dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
spin_unlock(&dev->dev_reservation_lock);
printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
}
spin_lock_irq(&dev->stats_lock);
dev->num_resets++;
spin_unlock_irq(&dev->stats_lock);
DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
(preempt_and_abort_list) ? "Preempt" : "TMR",
TRANSPORT(dev)->name);
return 0;
}