From f24b5cb818c6789e5d42d4881f34238a5fa0b40c Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Mon, 8 Oct 2012 09:23:54 +0200 Subject: [PATCH] [SCSI] qla2xxx: fix potential deadlock on ha->hardware_lock Lockdep reports: === [ cut here ] === ========================================================= [ INFO: possible irq lock inversion dependency detected ] 3.6.0-0.0.0.28.36b5ec9-default #1 Not tainted --------------------------------------------------------- qla2xxx_1_dpc/368 just changed the state of lock: (&(&ha->vport_slock)->rlock){+.....}, at: [] qla2x00_configure_hba+0x197/0x3c0 [qla2xxx] but this lock was taken by another, HARDIRQ-safe lock in the past: (&(&ha->hardware_lock)->rlock){-.....} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&ha->vport_slock)->rlock); local_irq_disable(); lock(&(&ha->hardware_lock)->rlock); lock(&(&ha->vport_slock)->rlock); lock(&(&ha->hardware_lock)->rlock); === [ cut here ] === Fix the potential deadlock by disabling IRQs while holding ha->vport_slock. Reported-and-tested-by: Srivatsa S. Bhat Signed-off-by: Jiri Kosina Acked-by: Saurav Kashyap Signed-off-by: James Bottomley --- drivers/scsi/qla2xxx/qla_init.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c index 799a58bb9859..48fca47384b7 100644 --- a/drivers/scsi/qla2xxx/qla_init.c +++ b/drivers/scsi/qla2xxx/qla_init.c @@ -2080,6 +2080,7 @@ qla2x00_configure_hba(scsi_qla_host_t *vha) uint8_t domain; char connect_type[22]; struct qla_hw_data *ha = vha->hw; + unsigned long flags; /* Get host addresses. */ rval = qla2x00_get_adapter_id(vha, @@ -2154,9 +2155,9 @@ qla2x00_configure_hba(scsi_qla_host_t *vha) vha->d_id.b.area = area; vha->d_id.b.al_pa = al_pa; - spin_lock(&ha->vport_slock); + spin_lock_irqsave(&ha->vport_slock, flags); qlt_update_vp_map(vha, SET_AL_PA); - spin_unlock(&ha->vport_slock); + spin_unlock_irqrestore(&ha->vport_slock, flags); if (!vha->flags.init_done) ql_log(ql_log_info, vha, 0x2010,