On 2021/01/28 23:43, Christoph Hellwig wrote:
> On Thu, Jan 28, 2021 at 07:39:21AM -0700, Jens Axboe wrote:
>> On 1/28/21 7:37 AM, Christoph Hellwig wrote:
>>> On Thu, Jan 28, 2021 at 03:36:19PM +0900, Damien Le Moal wrote:
>>>> Some block device drivers, e.g. the skd driver, call set_capacity() with
>>>> IRQ disabled. This results in lockdep ito complain about inconsistent
>>>> lock states ("inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage")
>>>> because set_capacity takes a block device bd_size_lock using the
>>>> functions spin_lock() and spin_unlock(). Ensure a consistent locking
>>>> state by replacing these calls with spin_lock_irqsave() and
>>>> spin_lock_irqrestore(). The same applies to bdev_set_nr_sectors().
>>>> With this fix, all lockdep complaints are resolved.
>>>
>>> I'd much rather fix the driver to not call set_capacity with irqs
>>> disabled..
>>
>> Agree, but that might be a bit beyond 5.10 at this point..
>
> True.
>
Agree, it was my initial intent to fix the driver itself to fix this problem.
However, the entire completion path code, where the set_capacity() call is, is
executed under a single spin_lock with IRQ disabled. That is pretty horrible and
will need major surgery to fix.
I can work on that for 5.12 if required, but I would rather leave it like this
and deprecate this driver so that we can remove it in a couple of releases or
so. The STEC cards are not sold anymore since many years ago and are not even
supported by the vendor anymore.
Should I start fixing this driver or go with deprecating it ?
--
Damien Le Moal
Western Digital Research
