Commit 9c6e164c authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Nicholas Bellinger
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target_core_alua: Use workqueue for ALUA transitioning 



Use a workqueue for processing ALUA state transitions; this allows
us to process implicit delay properly.

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent dfbce75a

drivers/target/target_core_alua.c

+124 −50
Original line number Diff line number Diff line
@@ -769,8 +769,7 @@ static int core_alua_write_tpg_metadata( 
 * Called with tg_pt_gp->tg_pt_gp_md_mutex held

 */

static int core_alua_update_tpg_primary_metadata(

	struct t10_alua_tg_pt_gp *tg_pt_gp,

	int primary_state)

	struct t10_alua_tg_pt_gp *tg_pt_gp)

{

	unsigned char *md_buf;

	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
@@ -789,7 +788,8 @@ static int core_alua_update_tpg_primary_metadata( 
			"tg_pt_gp_id=%hu\n"

			"alua_access_state=0x%02x\n"

			"alua_access_status=0x%02x\n",

			tg_pt_gp->tg_pt_gp_id, primary_state,

			tg_pt_gp->tg_pt_gp_id,

			tg_pt_gp->tg_pt_gp_alua_pending_state,

			tg_pt_gp->tg_pt_gp_alua_access_status);



	snprintf(path, ALUA_METADATA_PATH_LEN,
@@ -801,36 +801,17 @@ static int core_alua_update_tpg_primary_metadata( 
	return rc;

}



static int core_alua_do_transition_tg_pt(

	struct t10_alua_tg_pt_gp *tg_pt_gp,

	struct se_port *l_port,

	struct se_node_acl *nacl,

	int new_state,

	int explicit)

static void core_alua_do_transition_tg_pt_work(struct work_struct *work)

{

	struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,

		struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work.work);

	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;

	struct se_dev_entry *se_deve;

	struct se_lun_acl *lacl;

	struct se_port *port;

	struct t10_alua_tg_pt_gp_member *mem;



	/*

	 * Save the old primary ALUA access state, and set the current state

	 * to ALUA_ACCESS_STATE_TRANSITION.

	 */

	tg_pt_gp->tg_pt_gp_alua_previous_state =

		atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);

	tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;



	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,

			ALUA_ACCESS_STATE_TRANSITION);

	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?

				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :

				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;

	/*

	 * Check for the optional ALUA primary state transition delay

	 */

	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)

		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);

	bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==

			 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);



	spin_lock(&tg_pt_gp->tg_pt_gp_lock);

	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
@@ -865,9 +846,12 @@ static int core_alua_do_transition_tg_pt( 
			if (!lacl)

				continue;



			if (explicit &&

			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&

			   (l_port != NULL) && (l_port == port))

			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==

			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&

			   (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&

			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl) &&

			   (tg_pt_gp->tg_pt_gp_alua_port != NULL) &&

			    (tg_pt_gp->tg_pt_gp_alua_port == port))

				continue;



			core_scsi3_ua_allocate(lacl->se_lun_nacl,
@@ -895,7 +879,7 @@ static int core_alua_do_transition_tg_pt( 
	 */

	if (tg_pt_gp->tg_pt_gp_write_metadata) {

		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);

		core_alua_update_tpg_primary_metadata(tg_pt_gp, new_state);

		core_alua_update_tpg_primary_metadata(tg_pt_gp);

		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);

	}

	/*
@@ -910,6 +894,87 @@ static int core_alua_do_transition_tg_pt( 
		tg_pt_gp->tg_pt_gp_id,

		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_previous_state),

		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_pending_state));

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);

	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);

	smp_mb__after_atomic_dec();

	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);



	if (tg_pt_gp->tg_pt_gp_transition_complete)

		complete(tg_pt_gp->tg_pt_gp_transition_complete);

}



static int core_alua_do_transition_tg_pt(

	struct t10_alua_tg_pt_gp *tg_pt_gp,

	int new_state,

	int explicit)

{

	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;

	DECLARE_COMPLETION_ONSTACK(wait);



	/* Nothing to be done here */

	if (atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) == new_state)

		return 0;



	if (new_state == ALUA_ACCESS_STATE_TRANSITION)

		return -EAGAIN;



	/*

	 * Flush any pending transitions

	 */

	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs &&

	    atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==

	    ALUA_ACCESS_STATE_TRANSITION) {

		/* Just in case */

		tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;

		tg_pt_gp->tg_pt_gp_transition_complete = &wait;

		flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);

		wait_for_completion(&wait);

		tg_pt_gp->tg_pt_gp_transition_complete = NULL;

		return 0;

	}



	/*

	 * Save the old primary ALUA access state, and set the current state

	 * to ALUA_ACCESS_STATE_TRANSITION.

	 */

	tg_pt_gp->tg_pt_gp_alua_previous_state =

		atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);

	tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;



	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,

			ALUA_ACCESS_STATE_TRANSITION);

	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?

				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :

				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;



	/*

	 * Check for the optional ALUA primary state transition delay

	 */

	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)

		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);



	/*

	 * Take a reference for workqueue item

	 */

	spin_lock(&dev->t10_alua.tg_pt_gps_lock);

	atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);

	smp_mb__after_atomic_inc();

	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);



	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs) {

		unsigned long transition_tmo;



		transition_tmo = tg_pt_gp->tg_pt_gp_implicit_trans_secs * HZ;

		queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,

				   &tg_pt_gp->tg_pt_gp_transition_work,

				   transition_tmo);

	} else {

		tg_pt_gp->tg_pt_gp_transition_complete = &wait;

		queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,

				   &tg_pt_gp->tg_pt_gp_transition_work, 0);

		wait_for_completion(&wait);

		tg_pt_gp->tg_pt_gp_transition_complete = NULL;

	}



	return 0;

}
@@ -923,12 +988,10 @@ int core_alua_do_port_transition( 
	int explicit)

{

	struct se_device *dev;

	struct se_port *port;

	struct se_node_acl *nacl;

	struct t10_alua_lu_gp *lu_gp;

	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;

	struct t10_alua_tg_pt_gp *tg_pt_gp;

	int primary, valid_states;

	int primary, valid_states, rc = 0;



	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;

	if (core_alua_check_transition(new_state, valid_states, &primary) != 0)
@@ -950,11 +1013,13 @@ int core_alua_do_port_transition( 
		 * core_alua_do_transition_tg_pt() will always return

		 * success.

		 */

		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,

		l_tg_pt_gp->tg_pt_gp_alua_port = l_port;

		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;

		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,

						   new_state, explicit);

		atomic_dec(&lu_gp->lu_gp_ref_cnt);

		smp_mb__after_atomic_dec();

		return 0;

		return rc;

	}

	/*

	 * For all other LU groups aside from 'default_lu_gp', walk all of
@@ -989,11 +1054,11 @@ int core_alua_do_port_transition( 
				continue;



			if (l_tg_pt_gp == tg_pt_gp) {

				port = l_port;

				nacl = l_nacl;

				tg_pt_gp->tg_pt_gp_alua_port = l_port;

				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;

			} else {

				port = NULL;

				nacl = NULL;

				tg_pt_gp->tg_pt_gp_alua_port = NULL;

				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;

			}

			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);

			smp_mb__after_atomic_inc();
@@ -1002,12 +1067,14 @@ int core_alua_do_port_transition( 
			 * core_alua_do_transition_tg_pt() will always return

			 * success.

			 */

			core_alua_do_transition_tg_pt(tg_pt_gp, port,

					nacl, new_state, explicit);

			rc = core_alua_do_transition_tg_pt(tg_pt_gp,

					new_state, explicit);



			spin_lock(&dev->t10_alua.tg_pt_gps_lock);

			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);

			smp_mb__after_atomic_dec();

			if (rc)

				break;

		}

		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
@@ -1017,15 +1084,18 @@ int core_alua_do_port_transition( 
	}

	spin_unlock(&lu_gp->lu_gp_lock);



	if (!rc) {

		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"

			 " Group IDs: %hu %s transition to primary state: %s\n",

			 config_item_name(&lu_gp->lu_gp_group.cg_item),

		l_tg_pt_gp->tg_pt_gp_id, (explicit) ? "explicit" : "implicit",

			 l_tg_pt_gp->tg_pt_gp_id,

			 (explicit) ? "explicit" : "implicit",

			 core_alua_dump_state(new_state));

	}



	atomic_dec(&lu_gp->lu_gp_ref_cnt);

	smp_mb__after_atomic_dec();

	return 0;

	return rc;

}



/*
@@ -1379,6 +1449,8 @@ struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev, 
	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);

	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);

	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);

	INIT_DELAYED_WORK(&tg_pt_gp->tg_pt_gp_transition_work,

			  core_alua_do_transition_tg_pt_work);

	tg_pt_gp->tg_pt_gp_dev = dev;

	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,

		ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
@@ -1507,6 +1579,8 @@ void core_alua_free_tg_pt_gp( 
	dev->t10_alua.alua_tg_pt_gps_counter--;

	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);



	flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);



	/*

	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by

	 * core_alua_get_tg_pt_gp_by_name() in

include/target/target_core_base.h

+4 −0
Original line number Diff line number Diff line
@@ -302,6 +302,10 @@ struct t10_alua_tg_pt_gp { 
	struct config_group tg_pt_gp_group;

	struct list_head tg_pt_gp_list;

	struct list_head tg_pt_gp_mem_list;

	struct se_port *tg_pt_gp_alua_port;

	struct se_node_acl *tg_pt_gp_alua_nacl;

	struct delayed_work tg_pt_gp_transition_work;

	struct completion *tg_pt_gp_transition_complete;

};



struct t10_alua_tg_pt_gp_member {