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: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 0a00873..02d8e1a 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -969,7 +969,8 @@
* 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 @@
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);
/*