--- /dev/null
+/*******************************************************************************
+ * Filename: target_core_tmr.c
+ *
+ * This file contains SPC-3 task management infrastructure
+ *
+ * (c) Copyright 2009-2013 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/slab.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/export.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_configfs.h>
+
+#include "target_core_internal.h"
+#include "target_core_alua.h"
+#include "target_core_pr.h"
+
+int core_tmr_alloc_req(
+ struct se_cmd *se_cmd,
+ void *fabric_tmr_ptr,
+ u8 function,
+ gfp_t gfp_flags)
+{
+ struct se_tmr_req *tmr;
+
+ tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags);
+ if (!tmr) {
+ pr_err("Unable to allocate struct se_tmr_req\n");
+ return -ENOMEM;
+ }
+
+ se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB;
+ se_cmd->se_tmr_req = tmr;
+ tmr->task_cmd = se_cmd;
+ tmr->fabric_tmr_ptr = fabric_tmr_ptr;
+ tmr->function = function;
+ INIT_LIST_HEAD(&tmr->tmr_list);
+
+ return 0;
+}
+EXPORT_SYMBOL(core_tmr_alloc_req);
+
+void core_tmr_release_req(struct se_tmr_req *tmr)
+{
+ struct se_device *dev = tmr->tmr_dev;
+ unsigned long flags;
+
+ if (dev) {
+ spin_lock_irqsave(&dev->se_tmr_lock, flags);
+ list_del(&tmr->tmr_list);
+ spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
+ }
+
+ kfree(tmr);
+}
+
+static void core_tmr_handle_tas_abort(
+ struct se_node_acl *tmr_nacl,
+ struct se_cmd *cmd,
+ int tas)
+{
+ bool remove = true;
+ /*
+ * TASK ABORTED status (TAS) bit support
+ */
+ if ((tmr_nacl && (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) {
+ remove = false;
+ transport_send_task_abort(cmd);
+ }
+
+ transport_cmd_finish_abort(cmd, remove);
+}
+
+static int target_check_cdb_and_preempt(struct list_head *list,
+ struct se_cmd *cmd)
+{
+ struct t10_pr_registration *reg;
+
+ if (!list)
+ return 0;
+ list_for_each_entry(reg, list, pr_reg_abort_list) {
+ if (reg->pr_res_key == cmd->pr_res_key)
+ return 0;
+ }
+
+ return 1;
+}
+
+void core_tmr_abort_task(
+ struct se_device *dev,
+ struct se_tmr_req *tmr,
+ struct se_session *se_sess)
+{
+ struct se_cmd *se_cmd;
+ unsigned long flags;
+ int ref_tag;
+
+ spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+ list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
+
+ if (dev != se_cmd->se_dev)
+ continue;
+
+ /* skip task management functions, including tmr->task_cmd */
+ if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
+ continue;
+
+ ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
+ if (tmr->ref_task_tag != ref_tag)
+ continue;
+
+ printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
+ se_cmd->se_tfo->get_fabric_name(), ref_tag);
+
+ spin_lock(&se_cmd->t_state_lock);
+ if (se_cmd->transport_state & CMD_T_COMPLETE) {
+ printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
+ spin_unlock(&se_cmd->t_state_lock);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+ goto out;
+ }
+ se_cmd->transport_state |= CMD_T_ABORTED;
+ spin_unlock(&se_cmd->t_state_lock);
+
+ list_del_init(&se_cmd->se_cmd_list);
+ kref_get(&se_cmd->cmd_kref);
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+ cancel_work_sync(&se_cmd->work);
+ transport_wait_for_tasks(se_cmd);
+
+ target_put_sess_cmd(se_sess, se_cmd);
+ transport_cmd_finish_abort(se_cmd, true);
+
+ printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
+ " ref_tag: %d\n", ref_tag);
+ tmr->response = TMR_FUNCTION_COMPLETE;
+ return;
+ }
+ spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+out:
+ printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
+ tmr->ref_task_tag);
+ tmr->response = TMR_TASK_DOES_NOT_EXIST;
+}
+
+static void core_tmr_drain_tmr_list(
+ struct se_device *dev,
+ struct se_tmr_req *tmr,
+ struct list_head *preempt_and_abort_list)
+{
+ LIST_HEAD(drain_tmr_list);
+ struct se_tmr_req *tmr_p, *tmr_pp;
+ struct se_cmd *cmd;
+ unsigned long flags;
+ /*
+ * Release all pending and outgoing TMRs aside from the received
+ * LUN_RESET tmr..
+ */
+ spin_lock_irqsave(&dev->se_tmr_lock, flags);
+ 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_p == tmr)
+ continue;
+
+ cmd = tmr_p->task_cmd;
+ if (!cmd) {
+ pr_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 (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
+ continue;
+
+ spin_lock(&cmd->t_state_lock);
+ if (!(cmd->transport_state & CMD_T_ACTIVE)) {
+ spin_unlock(&cmd->t_state_lock);
+ continue;
+ }
+ if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
+ spin_unlock(&cmd->t_state_lock);
+ continue;
+ }
+ spin_unlock(&cmd->t_state_lock);
+
+ list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
+ }
+ spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
+
+ list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
+ list_del_init(&tmr_p->tmr_list);
+ cmd = tmr_p->task_cmd;
+
+ pr_debug("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);
+
+ transport_cmd_finish_abort(cmd, 1);
+ }
+}
+
+static void core_tmr_drain_state_list(
+ struct se_device *dev,
+ struct se_cmd *prout_cmd,
+ struct se_node_acl *tmr_nacl,
+ int tas,
+ struct list_head *preempt_and_abort_list)
+{
+ LIST_HEAD(drain_task_list);
+ struct se_cmd *cmd, *next;
+ unsigned long flags;
+
+ /*
+ * Complete outstanding commands 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(cmd, next, &dev->state_list, state_list) {
+ /*
+ * For PREEMPT_AND_ABORT usage, only process commands
+ * with a matching reservation key.
+ */
+ if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
+ continue;
+
+ /*
+ * Not aborting PROUT PREEMPT_AND_ABORT CDB..
+ */
+ if (prout_cmd == cmd)
+ continue;
+
+ list_move_tail(&cmd->state_list, &drain_task_list);
+ cmd->state_active = false;
+ }
+ spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+
+ while (!list_empty(&drain_task_list)) {
+ cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
+ list_del(&cmd->state_list);
+
+ pr_debug("LUN_RESET: %s cmd: %p"
+ " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
+ "cdb: 0x%02x\n",
+ (preempt_and_abort_list) ? "Preempt" : "", cmd,
+ cmd->se_tfo->get_task_tag(cmd), 0,
+ cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
+ cmd->t_task_cdb[0]);
+ pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
+ " -- CMD_T_ACTIVE: %d"
+ " CMD_T_STOP: %d CMD_T_SENT: %d\n",
+ cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
+ (cmd->transport_state & CMD_T_ACTIVE) != 0,
+ (cmd->transport_state & CMD_T_STOP) != 0,
+ (cmd->transport_state & CMD_T_SENT) != 0);
+
+ /*
+ * If the command may be queued onto a workqueue cancel it now.
+ *
+ * This is equivalent to removal from the execute queue in the
+ * loop above, but we do it down here given that
+ * cancel_work_sync may block.
+ */
+ if (cmd->t_state == TRANSPORT_COMPLETE)
+ cancel_work_sync(&cmd->work);
+
+ spin_lock_irqsave(&cmd->t_state_lock, flags);
+ target_stop_cmd(cmd, &flags);
+
+ cmd->transport_state |= CMD_T_ABORTED;
+ spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas);
+ }
+}
+
+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_node_acl *tmr_nacl = NULL;
+ struct se_portal_group *tmr_tpg = NULL;
+ int 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->dev_attrib.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) {
+ pr_debug("LUN_RESET: TMR caller fabric: %s"
+ " initiator port %s\n",
+ tmr_tpg->se_tpg_tfo->get_fabric_name(),
+ tmr_nacl->initiatorname);
+ }
+ }
+ pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n",
+ (preempt_and_abort_list) ? "Preempt" : "TMR",
+ dev->transport->name, tas);
+
+ core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
+ core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas,
+ preempt_and_abort_list);
+
+ /*
+ * Clear any legacy SPC-2 reservation when called during
+ * LOGICAL UNIT RESET
+ */
+ if (!preempt_and_abort_list &&
+ (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) {
+ spin_lock(&dev->dev_reservation_lock);
+ dev->dev_reserved_node_acl = NULL;
+ dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
+ spin_unlock(&dev->dev_reservation_lock);
+ pr_debug("LUN_RESET: SCSI-2 Released reservation\n");
+ }
+
+ atomic_long_inc(&dev->num_resets);
+
+ pr_debug("LUN_RESET: %s for [%s] Complete\n",
+ (preempt_and_abort_list) ? "Preempt" : "TMR",
+ dev->transport->name);
+ return 0;
+}
+
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