Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9e37d042 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Drop se_lun->lun_active for existing percpu lun_ref 



With se_port_t and t10_alua_tg_pt_gp_member being absored into se_lun,
there is no need for an extra atomic_t based reference count for PR
ALL_TG_PT=1 and ALUA access state transition.

Go ahead and use the existing percpu se_lun->lun_ref instead, and
convert the two special cases to percpu_ref_tryget_live() to avoid
se_lun if transport_clear_lun_ref() has already been invoked to
shutdown the se_lun.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 4cc987ea

drivers/target/target_core_alua.c

+3 −2
Original line number Diff line number Diff line
@@ -969,7 +969,8 @@ static void core_alua_do_transition_tg_pt_work(struct work_struct *work) 
		 * every I_T nexus other than the I_T nexus on which the SET

		 * TARGET PORT GROUPS command

		 */

		atomic_inc_mb(&lun->lun_active);

		if (!percpu_ref_tryget_live(&lun->lun_ref))

			continue;

		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);



		spin_lock_bh(&lun->lun_deve_lock);
@@ -998,7 +999,7 @@ static void core_alua_do_transition_tg_pt_work(struct work_struct *work) 
		spin_unlock_bh(&lun->lun_deve_lock);



		spin_lock(&tg_pt_gp->tg_pt_gp_lock);

		atomic_dec_mb(&lun->lun_active);

		percpu_ref_put(&lun->lun_ref);

	}

	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);

	/*

drivers/target/target_core_pr.c

+5 −4
Original line number Diff line number Diff line
@@ -704,7 +704,8 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( 
	 */

	spin_lock(&dev->se_port_lock);

	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {

		atomic_inc_mb(&lun_tmp->lun_active);

		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))

			continue;

		spin_unlock(&dev->se_port_lock);



		spin_lock_bh(&lun_tmp->lun_deve_lock);
@@ -751,7 +752,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( 
			if (ret < 0) {

				pr_err("core_scsi3_lunacl_depend"

						"_item() failed\n");

				atomic_dec_mb(&lun->lun_active);

				percpu_ref_put(&lun_tmp->lun_ref);

				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);

				goto out;

			}
@@ -770,7 +771,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( 
						deve_tmp->mapped_lun, NULL,

						sa_res_key, all_tg_pt, aptpl);

			if (!pr_reg_atp) {

				atomic_dec_mb(&lun_tmp->lun_active);

				percpu_ref_put(&lun_tmp->lun_ref);

				core_scsi3_lunacl_undepend_item(deve_tmp);

				goto out;

			}
@@ -782,7 +783,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( 
		spin_unlock_bh(&lun_tmp->lun_deve_lock);



		spin_lock(&dev->se_port_lock);

		atomic_dec_mb(&lun_tmp->lun_active);

		percpu_ref_put(&lun_tmp->lun_ref);

	}

	spin_unlock(&dev->se_port_lock);

drivers/target/target_core_tpg.c

+6 −4
Original line number Diff line number Diff line
@@ -607,7 +607,6 @@ struct se_lun *core_tpg_alloc_lun( 
	mutex_init(&lun->lun_tg_pt_md_mutex);

	INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);

	spin_lock_init(&lun->lun_tg_pt_gp_lock);

	atomic_set(&lun->lun_active, 0);

	lun->lun_tpg = tpg;



	return lun;
@@ -667,13 +666,16 @@ void core_tpg_remove_lun( 
	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);



	core_clear_lun_from_tpg(lun, tpg);

	/*

	 * Wait for any active I/O references to percpu se_lun->lun_ref to

	 * be released.  Also, se_lun->lun_ref is now used by PR and ALUA

	 * logic when referencing a remote target port during ALL_TGT_PT=1

	 * and generating UNIT_ATTENTIONs for ALUA access state transition.

	 */

	transport_clear_lun_ref(lun);



	mutex_lock(&tpg->tpg_lun_mutex);

	if (lun->lun_se_dev) {

		while (atomic_read(&lun->lun_active))

			cpu_relax();



		target_detach_tg_pt_gp(lun);



		spin_lock(&dev->se_port_lock);

include/target/target_core_base.h

+0 −1
Original line number Diff line number Diff line
@@ -721,7 +721,6 @@ struct se_lun { 
	struct t10_alua_tg_pt_gp *lun_tg_pt_gp;

	spinlock_t		lun_tg_pt_gp_lock;



	atomic_t		lun_active;

	struct se_portal_group	*lun_tpg;

	struct scsi_port_stats	lun_stats;

	struct config_group	lun_group;