target: Convert acl_node_lock to be IRQ-disabling

With qla2xxx, acl_node_lock is taken inside qla2xxx's hardware_lock,
which is taken in hardirq context.  This means acl_node_lock must become
an IRQ-disabling lock; in particular this fixes lockdep warnings along
the lines of

    ======================================================
    [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]

     (&(&se_tpg->acl_node_lock)->rlock){+.....}, at: [<ffffffffa026f872>] transport_deregister_session+0x92/0x140 [target_core_mod]

    and this task is already holding:
     (&(&ha->hardware_lock)->rlock){-.-...}, at: [<ffffffffa017c5e7>] qla_tgt_stop_phase1+0x57/0x2c0 [qla2xxx]
    which would create a new lock dependency:
     (&(&ha->hardware_lock)->rlock){-.-...} -> (&(&se_tpg->acl_node_lock)->rlock){+.....}

    but this new dependency connects a HARDIRQ-irq-safe lock:
     (&(&ha->hardware_lock)->rlock){-.-...}

    to a HARDIRQ-irq-unsafe lock:
     (&(&se_tpg->acl_node_lock)->rlock){+.....}

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 4b5237f500a..ca6e4a4df13 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -472,9 +472,9 @@ void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
 	struct se_dev_entry *deve;
 	u32 i;
 
-	spin_lock_bh(&tpg->acl_node_lock);
+	spin_lock_irq(&tpg->acl_node_lock);
 	list_for_each_entry(nacl, &tpg->acl_node_list, acl_list) {
-		spin_unlock_bh(&tpg->acl_node_lock);
+		spin_unlock_irq(&tpg->acl_node_lock);
 
 		spin_lock_irq(&nacl->device_list_lock);
 		for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
@@ -491,9 +491,9 @@ void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
 		}
 		spin_unlock_irq(&nacl->device_list_lock);
 
-		spin_lock_bh(&tpg->acl_node_lock);
+		spin_lock_irq(&tpg->acl_node_lock);
 	}
-	spin_unlock_bh(&tpg->acl_node_lock);
+	spin_unlock_irq(&tpg->acl_node_lock);
 }
 
 static struct se_port *core_alloc_port(struct se_device *dev)
@@ -1372,17 +1372,17 @@ struct se_lun *core_dev_add_lun(
 	 */
 	if (tpg->se_tpg_tfo->tpg_check_demo_mode(tpg)) {
 		struct se_node_acl *acl;
-		spin_lock_bh(&tpg->acl_node_lock);
+		spin_lock_irq(&tpg->acl_node_lock);
 		list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
 			if (acl->dynamic_node_acl &&
 			    (!tpg->se_tpg_tfo->tpg_check_demo_mode_login_only ||
 			     !tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg))) {
-				spin_unlock_bh(&tpg->acl_node_lock);
+				spin_unlock_irq(&tpg->acl_node_lock);
 				core_tpg_add_node_to_devs(acl, tpg);
-				spin_lock_bh(&tpg->acl_node_lock);
+				spin_lock_irq(&tpg->acl_node_lock);
 			}
 		}
-		spin_unlock_bh(&tpg->acl_node_lock);
+		spin_unlock_irq(&tpg->acl_node_lock);
 	}
 
 	return lun_p;