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SubjectRe: [PATCH] [RESEND] qla2xxx: fix potential deadlock on ha->hardware_lock
Hi Nick,

On Tue, 9 Oct 2012, 11:47am -0700, Nicholas A. Bellinger wrote:

> Hi Jiri, Andrew, Arun & Co,
>
--8<-- snipped --
>
> Also please have a look below for a few more related items I noticed
> while reviewing this patch..
>
>> drivers/scsi/qla2xxx/qla_init.c | 5 +++--
>> 1 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
>> index 799a58b..48fca47 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,
>>
>
> So while looking at other ->vport_slock + qlt_update_vp_map() usage, two
> more items caught my eye:
>
> In qla_mid.c:qla24xx_disable_vp() code:
>
> ret = qla24xx_control_vp(vha, VCE_COMMAND_DISABLE_VPS_LOGO_ALL);
> atomic_set(&vha->loop_state, LOOP_DOWN);
> atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
>
> /* Remove port id from vp target map */
> qlt_update_vp_map(vha, RESET_AL_PA);
>
> qla2x00_mark_vp_devices_dead(vha);
> atomic_set(&vha->vp_state, VP_FAILED);
>
> AFAICT all callers of qlt_update_vp_map() into qla_target.c code should
> be holding ->vport_slock. I'll send out a separate patch for this
> shortly.

Makes sense.

>
> And in qla_init.c:qla2x00_init_rings() code:
>
> for (que = 0; que < ha->max_rsp_queues; que++) {
> rsp = ha->rsp_q_map[que];
> if (!rsp)
> continue;
> /* Initialize response queue entries */
> qla2x00_init_response_q_entries(rsp);
> }
>
> spin_lock(&ha->vport_slock);
>
> spin_unlock(&ha->vport_slock);
>
> ha->tgt.atio_ring_ptr = ha->tgt.atio_ring;
> ha->tgt.atio_ring_index = 0;
> /* Initialize ATIO queue entries */
> qlt_init_atio_q_entries(vha);
>
> The usage of ->vport_slock seems to be now either unnecessary, or a
> result of some bad merge outside of qla2xxx target mode.
>
> Qlogic folks, can this (leftover..?) usage of ->vport_slock now be
> safety removed..?
>

Yes, this is a left over of code removal and can be safely removed. We
already have a patch queued internally for this.

--Arun

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