Hi Nicholas,
On 10/05/2012 12:14 AM, Nicholas A. Bellinger wrote:
> On Thu, 2012-10-04 at 21:11 +0530, Srivatsa S. Bhat wrote:
>> Hi Jiri,
>>
>> Thanks for taking a look!
>
> Hi Srivatsa & Jiri,
>
>>
>>> This seems to be real. You should be seeing that since 3.5-rc1 already
>>> though ... ?
>>>
>>> Does the patch below fix that?
>>>
>>
>> Yes, it does, thanks! But 3.6-rc kernels were booting fine as far as I remember.
>> I'll check again and get back tomorrow.
>>
>
> Thanks for testing with v3.7-rc0 code !
>
> Cc'ing the Qlogic folks here, as this irq lock inversion warning appears
> to be regression from v3.7-rc1 qla2xxx (initiator) LLD changes that went
> in recently via scsi.git.
>
Actually Jiri is right - I am seeing this with 3.5-rc1 kernel also. So its not
a regression from this merge window.. it was there all along!
Regards,
Srivatsa S. Bhat
>
>>>
>>> From: Jiri Kosina <jkosina@xxxxxxx>
>>> 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: [<ffffffffa009b377>] 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);
>>> <Interrupt>
>>> lock(&(&ha->hardware_lock)->rlock);
>>> === [ cut here ] ===
>>>
>>> Fix the potential deadlock by disabling IRQs while holding ha->vport_slock.
>>>
>>> Reported-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
>>> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
>>
>> Tested-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
>>
>> Regards,
>> Srivatsa S. Bhat
>>
>>> ---
>>> 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,
>>>
>>
--
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