From 9e37d042cfcb003b885bb4c531cd6f07f62647d1 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Wed, 20 May 2015 21:21:08 -0700 Subject: 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 Reviewed-by: Hannes Reinecke Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_tpg.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/target/target_core_tpg.c') diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index 5b30940ccaf2..b9fcf2c4898e 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -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); -- cgit v1.2.3