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Commit d050ffb9 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Re-org of core_tmr_lun_reset 



This patch is a re-orginzation of core_tmr_lun_reset() logic to properly
scan the active tmr_list, dev->state_task_list and qobj->qobj_list w/ the
relivent locks held, and performing a list_move_tail onto seperate local
scope lists before performing the full drain.

This involves breaking out the code into three seperate list specific
functions: core_tmr_drain_tmr_list(), core_tmr_drain_task_list() and
core_tmr_drain_cmd_list().

(nab: Include target: Remove non-active tasks from execute list during
      LUN_RESET patch to address original breakage)

Reported-by: default avatarRoland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: default avatarNicholas Bellinger <nab@risingtidesystems.com>
parent 79a7fef2

drivers/target/target_core_tmr.c

+125 −72
Original line number Diff line number Diff line
@@ -66,15 +66,16 @@ void core_tmr_release_req( 
	struct se_tmr_req *tmr)

{

	struct se_device *dev = tmr->tmr_dev;

	unsigned long flags;



	if (!dev) {

		kmem_cache_free(se_tmr_req_cache, tmr);

		return;

	}



	spin_lock_irq(&dev->se_tmr_lock);

	spin_lock_irqsave(&dev->se_tmr_lock, flags);

	list_del(&tmr->tmr_list);

	spin_unlock_irq(&dev->se_tmr_lock);

	spin_unlock_irqrestore(&dev->se_tmr_lock, flags);



	kmem_cache_free(se_tmr_req_cache, tmr);

}
@@ -99,54 +100,20 @@ static void core_tmr_handle_tas_abort( 
	transport_cmd_finish_abort(cmd, 0);

}



int core_tmr_lun_reset(

static void core_tmr_drain_tmr_list(

	struct se_device *dev,

	struct se_tmr_req *tmr,

	struct list_head *preempt_and_abort_list,

	struct se_cmd *prout_cmd)

	struct list_head *preempt_and_abort_list)

{

	struct se_cmd *cmd, *tcmd;

	struct se_node_acl *tmr_nacl = NULL;

	struct se_portal_group *tmr_tpg = NULL;

	struct se_queue_obj *qobj = &dev->dev_queue_obj;

	LIST_HEAD(drain_tmr_list);

	struct se_tmr_req *tmr_p, *tmr_pp;

	struct se_task *task, *task_tmp;

	struct se_cmd *cmd;

	unsigned long flags;

	int fe_count, 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->se_sub_dev->se_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);

	/*

	 * Release all pending and outgoing TMRs aside from the received

	 * LUN_RESET tmr..

	 */

	spin_lock_irq(&dev->se_tmr_lock);

	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.
@@ -168,29 +135,48 @@ int core_tmr_lun_reset( 
		    (core_scsi3_check_cdb_abort_and_preempt(

					preempt_and_abort_list, cmd) != 0))

			continue;

		spin_unlock_irq(&dev->se_tmr_lock);



		spin_lock_irqsave(&cmd->t_state_lock, flags);

		spin_lock(&cmd->t_state_lock);

		if (!atomic_read(&cmd->t_transport_active)) {

			spin_unlock_irqrestore(&cmd->t_state_lock, flags);

			spin_lock_irq(&dev->se_tmr_lock);

			spin_unlock(&cmd->t_state_lock);

			continue;

		}

		if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {

			spin_unlock_irqrestore(&cmd->t_state_lock, flags);

			spin_lock_irq(&dev->se_tmr_lock);

			spin_unlock(&cmd->t_state_lock);

			continue;

		}

		spin_unlock(&cmd->t_state_lock);



		list_move_tail(&tmr->tmr_list, &drain_tmr_list);

	}

	spin_unlock_irqrestore(&dev->se_tmr_lock, flags);



	while (!list_empty(&drain_tmr_list)) {

		tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);

		list_del(&tmr->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);

		spin_unlock_irqrestore(&cmd->t_state_lock, flags);

			(preempt_and_abort_list) ? "Preempt" : "", tmr,

			tmr->function, tmr->response, cmd->t_state);



		transport_cmd_finish_abort_tmr(cmd);

		spin_lock_irq(&dev->se_tmr_lock);

	}

	spin_unlock_irq(&dev->se_tmr_lock);

}



static void core_tmr_drain_task_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;

	struct se_task *task, *task_tmp;

	unsigned long flags;

	int fe_count;

	/*

	 * Complete outstanding struct se_task CDBs with TASK_ABORTED SAM status.

	 * This is following sam4r17, section 5.6 Aborting commands, Table 38
@@ -235,10 +221,24 @@ int core_tmr_lun_reset( 
		if (prout_cmd == cmd)

			continue;



		list_del(&task->t_state_list);

		list_move_tail(&task->t_state_list, &drain_task_list);

		atomic_set(&task->task_state_active, 0);

		/*

		 * Remove from task execute list before processing drain_task_list

		 */

		if (atomic_read(&task->task_execute_queue) != 0) {

			list_del(&task->t_execute_list);

			atomic_set(&task->task_execute_queue, 0);

			atomic_dec(&dev->execute_tasks);

		}

	}

	spin_unlock_irqrestore(&dev->execute_task_lock, flags);



	while (!list_empty(&drain_task_list)) {

		task = list_entry(drain_task_list.next, struct se_task, t_state_list);

		list_del(&task->t_state_list);

		cmd = task->task_se_cmd;



		spin_lock_irqsave(&cmd->t_state_lock, flags);

		pr_debug("LUN_RESET: %s cmd: %p task: %p"

			" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
@@ -274,20 +274,14 @@ int core_tmr_lun_reset( 


			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(&cmd->t_task_cdbs_ex_left)) {

			spin_unlock_irqrestore(

					&cmd->t_state_lock, flags);

			spin_unlock_irqrestore(&cmd->t_state_lock, flags);

			pr_debug("LUN_RESET: Skipping task: %p, dev: %p for"

				" t_task_cdbs_ex_left: %d\n", task, dev,

				atomic_read(&cmd->t_task_cdbs_ex_left));



			spin_lock_irqsave(&dev->execute_task_lock, flags);

			continue;

		}

		fe_count = atomic_read(&cmd->t_fe_count);
@@ -297,22 +291,31 @@ int core_tmr_lun_reset( 
				" task: %p, t_fe_count: %d dev: %p\n", task,

				fe_count, dev);

			atomic_set(&cmd->t_transport_aborted, 1);

			spin_unlock_irqrestore(&cmd->t_state_lock,

						flags);

			core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);

			spin_unlock_irqrestore(&cmd->t_state_lock, flags);



			spin_lock_irqsave(&dev->execute_task_lock, flags);

			core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);

			continue;

		}

		pr_debug("LUN_RESET: Got t_transport_active = 0 for task: %p,"

			" t_fe_count: %d dev: %p\n", task, fe_count, dev);

		atomic_set(&cmd->t_transport_aborted, 1);

		spin_unlock_irqrestore(&cmd->t_state_lock, flags);

		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);



		spin_lock_irqsave(&dev->execute_task_lock, flags);

		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);

	}

	spin_unlock_irqrestore(&dev->execute_task_lock, flags);

}



static void core_tmr_drain_cmd_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_cmd_list);

	struct se_queue_obj *qobj = &dev->dev_queue_obj;

	struct se_cmd *cmd, *tcmd;

	unsigned long flags;

	/*

	 * Release all commands remaining in the struct se_device cmd queue.

	 *
@@ -337,11 +340,16 @@ int core_tmr_lun_reset( 
		if (prout_cmd == cmd)

			continue;



		atomic_dec(&cmd->t_transport_queue_active);

		atomic_set(&cmd->t_transport_queue_active, 0);

		atomic_dec(&qobj->queue_cnt);

		list_del_init(&cmd->se_queue_node);

		list_move_tail(&cmd->se_queue_node, &drain_cmd_list);

	}

	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);



	while (!list_empty(&drain_cmd_list)) {

		cmd = list_entry(drain_cmd_list.next, struct se_cmd, se_queue_node);

		list_del_init(&cmd->se_queue_node);



		pr_debug("LUN_RESET: %s from Device Queue: cmd: %p t_state:"

			" %d t_fe_count: %d\n", (preempt_and_abort_list) ?

			"Preempt" : "", cmd, cmd->t_state,
@@ -353,9 +361,53 @@ int core_tmr_lun_reset( 


		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,

				atomic_read(&cmd->t_fe_count));

		spin_lock_irqsave(&qobj->cmd_queue_lock, flags);

	}

	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

}



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->se_sub_dev->se_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_task_list(dev, prout_cmd, tmr_nacl, tas,

				preempt_and_abort_list);

	core_tmr_drain_cmd_list(dev, prout_cmd, tmr_nacl, tas,

				preempt_and_abort_list);

	/*

	 * Clear any legacy SPC-2 reservation when called during

	 * LOGICAL UNIT RESET
@@ -378,3 +430,4 @@ int core_tmr_lun_reset( 
			dev->transport->name);

	return 0;

}