target: Drop left-over se_lun->lun_cmd_list shutdown code

Now with percpu refcounting for se_lun in place, go ahead and drop
the legacy per se_cmd accounting for se_lun shutdown.

This includes __transport_clear_lun_from_sessions(), the associated
transport_lun_wait_for_tasks() logic, along with a handful of now
unused se_cmd structure members and ->transport_state bits.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 4 insertions, 232 deletions

diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index f321af04ef0..f697f8baec5 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -654,9 +654,7 @@ static int core_tpg_setup_virtual_lun0(struct se_portal_group *se_tpg)
 	atomic_set(&lun->lun_acl_count, 0);
 	init_completion(&lun->lun_shutdown_comp);
 	INIT_LIST_HEAD(&lun->lun_acl_list);
-	INIT_LIST_HEAD(&lun->lun_cmd_list);
 	spin_lock_init(&lun->lun_acl_lock);
-	spin_lock_init(&lun->lun_cmd_lock);
 	spin_lock_init(&lun->lun_sep_lock);
 	init_completion(&lun->lun_ref_comp);
 
@@ -706,9 +704,7 @@ int core_tpg_register(
 		atomic_set(&lun->lun_acl_count, 0);
 		init_completion(&lun->lun_shutdown_comp);
 		INIT_LIST_HEAD(&lun->lun_acl_list);
-		INIT_LIST_HEAD(&lun->lun_cmd_list);
 		spin_lock_init(&lun->lun_acl_lock);
-		spin_lock_init(&lun->lun_cmd_lock);
 		spin_lock_init(&lun->lun_sep_lock);
 		init_completion(&lun->lun_ref_comp);
 	}
@@ -849,14 +845,6 @@ int core_tpg_post_addlun(
 	return 0;
 }
 
-static void core_tpg_shutdown_lun(
-	struct se_portal_group *tpg,
-	struct se_lun *lun)
-{
-	core_clear_lun_from_tpg(lun, tpg);
-	transport_clear_lun_ref(lun);
-}
-
 struct se_lun *core_tpg_pre_dellun(
 	struct se_portal_group *tpg,
 	u32 unpacked_lun)
@@ -891,7 +879,8 @@ int core_tpg_post_dellun(
 	struct se_portal_group *tpg,
 	struct se_lun *lun)
 {
-	core_tpg_shutdown_lun(tpg, lun);
+	core_clear_lun_from_tpg(lun, tpg);
+	transport_clear_lun_ref(lun);
 
 	core_dev_unexport(lun->lun_se_dev, tpg, lun);
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index ad143d7293e..e0669ac9278 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -505,23 +505,6 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 	if (write_pending)
 		cmd->t_state = TRANSPORT_WRITE_PENDING;
 
-	/*
-	 * Determine if IOCTL context caller in requesting the stopping of this
-	 * command for LUN shutdown purposes.
-	 */
-	if (cmd->transport_state & CMD_T_LUN_STOP) {
-		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
-			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
-
-		cmd->transport_state &= ~CMD_T_ACTIVE;
-		if (remove_from_lists)
-			target_remove_from_state_list(cmd);
-		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-
-		complete(&cmd->transport_lun_stop_comp);
-		return 1;
-	}
-
 	if (remove_from_lists) {
 		target_remove_from_state_list(cmd);
 
@@ -1078,13 +1061,10 @@ void transport_init_se_cmd(
 	int task_attr,
 	unsigned char *sense_buffer)
 {
-	INIT_LIST_HEAD(&cmd->se_lun_node);
 	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->transport_lun_fe_stop_comp);
-	init_completion(&cmd->transport_lun_stop_comp);
 	init_completion(&cmd->t_transport_stop_comp);
 	init_completion(&cmd->cmd_wait_comp);
 	init_completion(&cmd->task_stop_comp);
@@ -1705,29 +1685,14 @@ void target_execute_cmd(struct se_cmd *cmd)
 	/*
 	 * If the received CDB has aleady been aborted stop processing it here.
 	 */
-	if (transport_check_aborted_status(cmd, 1)) {
-		complete(&cmd->transport_lun_stop_comp);
+	if (transport_check_aborted_status(cmd, 1))
 		return;
-	}
 
 	/*
-	 * Determine if IOCTL context caller in requesting the stopping of this
-	 * command for LUN shutdown purposes.
-	 */
-	spin_lock_irq(&cmd->t_state_lock);
-	if (cmd->transport_state & CMD_T_LUN_STOP) {
-		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
-			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
-
-		cmd->transport_state &= ~CMD_T_ACTIVE;
-		spin_unlock_irq(&cmd->t_state_lock);
-		complete(&cmd->transport_lun_stop_comp);
-		return;
-	}
-	/*
 	 * Determine if frontend context caller is requesting the stopping of
 	 * this command for frontend exceptions.
 	 */
+	spin_lock_irq(&cmd->t_state_lock);
 	if (cmd->transport_state & CMD_T_STOP) {
 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
 			__func__, __LINE__,
@@ -2390,149 +2355,6 @@ void target_wait_for_sess_cmds(struct se_session *se_sess)
 }
 EXPORT_SYMBOL(target_wait_for_sess_cmds);
 
-/*	transport_lun_wait_for_tasks():
- *
- *	Called from ConfigFS context to stop the passed struct se_cmd to allow
- *	an struct se_lun to be successfully shutdown.
- */
-static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	/*
-	 * If the frontend has already requested this struct se_cmd to
-	 * be stopped, we can safely ignore this struct se_cmd.
-	 */
-	spin_lock_irqsave(&cmd->t_state_lock, flags);
-	if (cmd->transport_state & CMD_T_STOP) {
-		cmd->transport_state &= ~CMD_T_LUN_STOP;
-
-		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
-			 cmd->se_tfo->get_task_tag(cmd));
-		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-		transport_cmd_check_stop(cmd, false, false);
-		return -EPERM;
-	}
-	cmd->transport_state |= CMD_T_LUN_FE_STOP;
-	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-
-	// XXX: audit task_flags checks.
-	spin_lock_irqsave(&cmd->t_state_lock, flags);
-	if ((cmd->transport_state & CMD_T_BUSY) &&
-	    (cmd->transport_state & CMD_T_SENT)) {
-		if (!target_stop_cmd(cmd, &flags))
-			ret++;
-	}
-	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-
-	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
-			" %d\n", cmd, ret);
-	if (!ret) {
-		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
-				cmd->se_tfo->get_task_tag(cmd));
-		wait_for_completion(&cmd->transport_lun_stop_comp);
-		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
-				cmd->se_tfo->get_task_tag(cmd));
-	}
-
-	return 0;
-}
-
-static void __transport_clear_lun_from_sessions(struct se_lun *lun)
-{
-	struct se_cmd *cmd = NULL;
-	unsigned long lun_flags, cmd_flags;
-	/*
-	 * Do exception processing and return CHECK_CONDITION status to the
-	 * Initiator Port.
-	 */
-	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
-	while (!list_empty(&lun->lun_cmd_list)) {
-		cmd = list_first_entry(&lun->lun_cmd_list,
-		       struct se_cmd, se_lun_node);
-		list_del_init(&cmd->se_lun_node);
-
-		spin_lock(&cmd->t_state_lock);
-		pr_debug("SE_LUN[%d] - Setting cmd->transport"
-			"_lun_stop for  ITT: 0x%08x\n",
-			cmd->se_lun->unpacked_lun,
-			cmd->se_tfo->get_task_tag(cmd));
-		cmd->transport_state |= CMD_T_LUN_STOP;
-		spin_unlock(&cmd->t_state_lock);
-
-		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
-
-		if (!cmd->se_lun) {
-			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
-				cmd->se_tfo->get_task_tag(cmd),
-				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
-			BUG();
-		}
-		/*
-		 * If the Storage engine still owns the iscsi_cmd_t, determine
-		 * and/or stop its context.
-		 */
-		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
-			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
-			cmd->se_tfo->get_task_tag(cmd));
-
-		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
-			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
-			continue;
-		}
-
-		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
-			"_wait_for_tasks(): SUCCESS\n",
-			cmd->se_lun->unpacked_lun,
-			cmd->se_tfo->get_task_tag(cmd));
-
-		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
-		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
-			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
-			goto check_cond;
-		}
-		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
-		target_remove_from_state_list(cmd);
-		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
-
-		/*
-		 * The Storage engine stopped this struct se_cmd before it was
-		 * send to the fabric frontend for delivery back to the
-		 * Initiator Node.  Return this SCSI CDB back with an
-		 * CHECK_CONDITION status.
-		 */
-check_cond:
-		transport_send_check_condition_and_sense(cmd,
-				TCM_NON_EXISTENT_LUN, 0);
-		/*
-		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
-		 * be released, notify the waiting thread now that LU has
-		 * finished accessing it.
-		 */
-		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
-		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
-			pr_debug("SE_LUN[%d] - Detected FE stop for"
-				" struct se_cmd: %p ITT: 0x%08x\n",
-				lun->unpacked_lun,
-				cmd, cmd->se_tfo->get_task_tag(cmd));
-
-			spin_unlock_irqrestore(&cmd->t_state_lock,
-					cmd_flags);
-			transport_cmd_check_stop(cmd, false, false);
-			complete(&cmd->transport_lun_fe_stop_comp);
-			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
-			continue;
-		}
-		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
-			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
-
-		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
-		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
-	}
-	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
-}
-
 static int transport_clear_lun_ref_thread(void *p)
 {
 	struct se_lun *lun = p;
@@ -2583,43 +2405,6 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 		return false;
 	}
-	/*
-	 * If we are already stopped due to an external event (ie: LUN shutdown)
-	 * sleep until the connection can have the passed struct se_cmd back.
-	 * The cmd->transport_lun_stopped_sem will be upped by
-	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
-	 * has completed its operation on the struct se_cmd.
-	 */
-	if (cmd->transport_state & CMD_T_LUN_STOP) {
-		pr_debug("wait_for_tasks: Stopping"
-			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
-			"_stop_comp); for ITT: 0x%08x\n",
-			cmd->se_tfo->get_task_tag(cmd));
-		/*
-		 * There is a special case for WRITES where a FE exception +
-		 * LUN shutdown means ConfigFS context is still sleeping on
-		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
-		 * We go ahead and up transport_lun_stop_comp just to be sure
-		 * here.
-		 */
-		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-		complete(&cmd->transport_lun_stop_comp);
-		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
-		spin_lock_irqsave(&cmd->t_state_lock, flags);
-
-		target_remove_from_state_list(cmd);
-		/*
-		 * At this point, the frontend who was the originator of this
-		 * struct se_cmd, now owns the structure and can be released through
-		 * normal means below.
-		 */
-		pr_debug("wait_for_tasks: Stopped"
-			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
-			"stop_comp); for ITT: 0x%08x\n",
-			cmd->se_tfo->get_task_tag(cmd));
-
-		cmd->transport_state &= ~CMD_T_LUN_STOP;
-	}
 
 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 7a870f6add7..b12fc43b546 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -574,10 +574,8 @@ static int target_xcopy_init_pt_lun(
 		return -ENOMEM;
 	}
 	init_completion(&pt_cmd->se_lun->lun_shutdown_comp);
-	INIT_LIST_HEAD(&pt_cmd->se_lun->lun_cmd_list);
 	INIT_LIST_HEAD(&pt_cmd->se_lun->lun_acl_list);
 	spin_lock_init(&pt_cmd->se_lun->lun_acl_lock);
-	spin_lock_init(&pt_cmd->se_lun->lun_cmd_lock);
 	spin_lock_init(&pt_cmd->se_lun->lun_sep_lock);
 	init_completion(&pt_cmd->se_lun->lun_ref_comp);