• Roland Dreier's avatar
    target: Convert acl_node_lock to be IRQ-disabling · 28638887
    Roland Dreier authored
    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: default avatarRoland Dreier <roland@purestorage.com>
    Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
    28638887
target_core_pr.c 129 KB