[RFC PATCH 14/19] Target_Core_Mod Task Management infrastructure

* [RFC PATCH 14/19] Target_Core_Mod Task Management infrastructure
@ 2009-09-12  1:57 Nicholas A. Bellinger
  0 siblings, 0 replies; 2+ messages in thread
From: Nicholas A. Bellinger @ 2009-09-12  1:57 UTC (permalink / raw)
  To: LKML, linux-scsi
  Cc: Andrew Morton, Greg KH, Douglas Gilbert, James Bottomley,
	Hannes Reinecke, FUJITA Tomonori, Mike Christie, Joel Becker,
	Martin K. Petersen, Christoph Hellwig, Linus Torvalds,
	Alan Stern, Boaz Harrosh, Florian Haas, Philipp Reisner

[RFC PATCH 14/19] Target_Core_Mod Task Management infrastructure

This patch adds SPC-3 task management infrastructure and functionality for LUN_RESET and
in combination with handling Persistent Reservation PREEMPT_AND_ABORT service action

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
new file mode 100644
index 0000000..29e46d7
--- /dev/null
+++ b/drivers/target/target_core_tmr.c
@@ -0,0 +1,397 @@
+/*******************************************************************************
+ * Filename:  target_core_tmr.c
+ *
+ * This file contains SPC-3 task management infrastructure
+ *
+ * Copyright (c) 2009 Rising Tide, Inc.
+ * Copyright (c) 2009 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.
+ *
+ ******************************************************************************/
+
+#define TARGET_CORE_TMR_C
+
+#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_hba.h>
+#include <target/target_core_pr.h>
+#include <target/target_core_seobj.h>
+#include <target/target_core_tmr.h>
+#include <target/target_core_transport.h>
+#include <target/target_core_alua.h>
+#include <target/target_core_transport_plugin.h>
+#include <target/target_core_fabric_ops.h>
+#include <target/target_core_configfs.h>
+
+#undef TARGET_CORE_TMR_C
+
+#define DEBUG_LUN_RESET
+#ifdef DEBUG_LUN_RESET
+#define DEBUG_LR(x...) printk(KERN_INFO x)
+#else
+#define DEBUG_LR(x...)
+#endif
+
+se_tmr_req_t *core_tmr_alloc_req(
+	se_cmd_t *se_cmd,
+	void *fabric_tmr_ptr,
+	u8 function)
+{
+	se_tmr_req_t *tmr;
+
+	tmr = kmem_cache_zalloc(se_tmr_req_cache, GFP_KERNEL);
+	if (!(tmr)) {
+		printk(KERN_ERR "Unable to allocate se_tmr_req_t\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);
+
+/*
+ * Called with se_device_t->se_tmr_lock held.
+ */
+void __core_tmr_release_req(
+	se_tmr_req_t *tmr)
+{
+	list_del(&tmr->tmr_list);
+	kmem_cache_free(se_tmr_req_cache, tmr);
+}
+
+void core_tmr_release_req(
+	se_tmr_req_t *tmr)
+{
+	se_device_t *dev = tmr->tmr_dev;
+
+	spin_lock(&dev->se_tmr_lock);
+	__core_tmr_release_req(tmr);
+	spin_unlock(&dev->se_tmr_lock);
+}
+
+int core_tmr_lun_reset(
+	se_device_t *dev,
+	se_tmr_req_t *tmr,
+	struct list_head *preempt_and_abort_list,
+	se_cmd_t *prout_cmd)
+{
+	se_cmd_t *cmd;
+	se_queue_req_t *qr, *qr_tmp;
+	se_node_acl_t *tmr_nacl = NULL;
+	se_portal_group_t *tmr_tpg = NULL;
+	se_queue_obj_t *qobj = dev->dev_queue_obj;
+	se_tmr_req_t *tmr_p, *tmr_pp;
+	se_task_t *task, *task_tmp;
+	unsigned long flags;
+	int fe_count, state, tas;
+	/*
+	 * TASK_ABORTED status bit, this is configurable via ConfigFS
+	 * se_device_t 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 se_device_t 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 se_cmd_t 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);
+
+		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);
+
+		transport_cmd_finish_abort_tmr(cmd);
+		spin_lock(&dev->se_tmr_lock);
+	}
+	spin_unlock(&dev->se_tmr_lock);
+	/*
+	 * Complete outstanding se_task_t 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);
+			down(&task->task_stop_sem);
+			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);
+		}
+		__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);
+			spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
+						flags);
+			if (fe_count) {
+				/*
+				 * 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);
+			} else
+				transport_cmd_finish_abort(cmd, 1);
+
+			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);
+		spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
+
+		if (fe_count) {
+			/*
+			 * 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);
+		} else
+			transport_cmd_finish_abort(cmd, 1);
+
+		spin_lock_irqsave(&dev->execute_task_lock, flags);
+	}
+	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+	/*
+	 * Release all commands remaining in the se_device_t cmd queue.
+	 *
+	 * This follows the same logic as above for the se_device_t
+	 * se_task_t state list, where commands are returned with
+	 * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
+	 * reference, otherwise the se_cmd_t is released.
+	 */
+	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
+	list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
+		cmd = (se_cmd_t *)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));
+
+		if (atomic_read(&T_TASK(cmd)->t_fe_count)) {
+			/*
+			 * 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);
+		} else
+			transport_cmd_finish_abort(cmd, 1);
+
+		spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
+	}
+	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+
+#ifdef SNMP_SUPPORT
+	spin_lock(&dev->stats_lock);
+	dev->num_resets++;
+	spin_unlock(&dev->stats_lock);
+#endif /* SNMP_SUPPORT */
+
+	DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
+			(preempt_and_abort_list) ? "Preempt" : "TMR",
+			TRANSPORT(dev)->name);
+	return 0;
+}
diff --git a/include/target/target_core_tmr.h b/include/target/target_core_tmr.h
new file mode 100644
index 0000000..c649b92
--- /dev/null
+++ b/include/target/target_core_tmr.h
@@ -0,0 +1,43 @@
+#ifndef TARGET_CORE_TMR_H
+#define TARGET_CORE_TMR_H
+
+/* task management function values */
+#ifdef ABORT_TASK
+#undef ABORT_TASK
+#endif /* ABORT_TASK */
+#define ABORT_TASK				1
+#ifdef ABORT_TASK_SET
+#undef ABORT_TASK_SET
+#endif /* ABORT_TASK_SET */
+#define ABORT_TASK_SET				2
+#ifdef CLEAR_ACA
+#undef CLEAR_ACA
+#endif /* CLEAR_ACA */
+#define CLEAR_ACA				3
+#ifdef CLEAR_TASK_SET
+#undef CLEAR_TASK_SET
+#endif /* CLEAR_TASK_SET */
+#define CLEAR_TASK_SET				4
+#define LUN_RESET				5
+#define TARGET_WARM_RESET			6
+#define TARGET_COLD_RESET			7
+#define TASK_REASSIGN				8
+
+/* task management response values */
+#define TMR_FUNCTION_COMPLETE			0
+#define TMR_TASK_DOES_NOT_EXIST			1
+#define TMR_LUN_DOES_NOT_EXIST			2
+#define TMR_TASK_STILL_ALLEGIANT		3
+#define TMR_TASK_FAILOVER_NOT_SUPPORTED		4
+#define TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED	5
+#define TMR_FUNCTION_AUTHORIZATION_FAILED	6
+#define TMR_FUNCTION_REJECTED			255
+
+extern struct kmem_cache *se_tmr_req_cache;
+
+extern struct se_tmr_req_s *core_tmr_alloc_req(struct se_cmd_s *, void *, u8);
+extern void core_tmr_release_req(struct se_tmr_req_s *);
+extern int core_tmr_lun_reset(struct se_device_s *, struct se_tmr_req_s *,
+				struct list_head *, struct se_cmd_s *);
+
+#endif /* TARGET_CORE_TMR_H */




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