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, 4 insertions, 4 deletions

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 1c1b849cd4fb..7fd3a161f7cc 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -1598,14 +1598,14 @@ static int core_scsi3_decode_spec_i_port(
                          * from the decoded fabric module specific TransportID
                          * at *i_str.
                          */
-                        spin_lock_bh(&tmp_tpg->acl_node_lock);
+                        spin_lock_irq(&tmp_tpg->acl_node_lock);
                         dest_node_acl = __core_tpg_get_initiator_node_acl(
                                                 tmp_tpg, i_str);
                         if (dest_node_acl) {
                                 atomic_inc(&dest_node_acl->acl_pr_ref_count);
                                 smp_mb__after_atomic_inc();
                         }
-                        spin_unlock_bh(&tmp_tpg->acl_node_lock);
+                        spin_unlock_irq(&tmp_tpg->acl_node_lock);
 
                         if (!dest_node_acl) {
                                 core_scsi3_tpg_undepend_item(tmp_tpg);
@@ -3496,14 +3496,14 @@ after_iport_check:
         /*
          * Locate the destination struct se_node_acl from the received Transport ID
          */
-        spin_lock_bh(&dest_se_tpg->acl_node_lock);
+        spin_lock_irq(&dest_se_tpg->acl_node_lock);
         dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
                                 initiator_str);
         if (dest_node_acl) {
                 atomic_inc(&dest_node_acl->acl_pr_ref_count);
                 smp_mb__after_atomic_inc();
         }
-        spin_unlock_bh(&dest_se_tpg->acl_node_lock);
+        spin_unlock_irq(&dest_se_tpg->acl_node_lock);
 
         if (!dest_node_acl) {
                 pr_err("Unable to locate %s dest_node_acl for"