Initial import

1 files changed, 389 insertions, 0 deletions

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
new file mode 100644
index 000000000..315ec3458
--- /dev/null
+++ b/drivers/target/target_core_tmr.c
@@ -0,0 +1,389 @@
+/*******************************************************************************
+ * 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;
+}
+