linux-kernel - Re: [PATCH] mtd: blktrans: change blktrans_getgeo rerurn value

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Message-ID: <555D8002.4050006@windriver.com>
Date:	Thu, 21 May 2015 14:49:38 +0800
From:	Wenlin Kang <wenlin.kang@...driver.com>
To:	nick <xerofoify@...il.com>,
	Brian Norris <computersforpeace@...il.com>
CC:	<linux-mtd@...ts.infradead.org>, <dwmw2@...radead.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mtd: blktrans: change blktrans_getgeo rerurn value

On 2015年05月21日 03:47, nick wrote:
>
> On 2015-05-20 03:33 PM, Brian Norris wrote:
>> Hi Wenlin,
>>
>> In the subject:
>>
>> s/rerurn/return/

    Thanks for pointing out this, I will modify it.

>>
>> On Wed, May 13, 2015 at 02:29:16PM +0800, Wenlin Kang wrote:
>>> Modify function blktrans_getgeo()'s return value to -ENXIO when
>>> dev->tr->getgeo == NULL.
>>>
>>> We shouldn't make the return value to 0 when dev->tr->getgeo == NULL,
>>> because the function blktrans_getgeo() has an output value "hd_geometry"
>>> which is usually used by some application, if return 0, it will make some
>>> application get the wrong information.
>>>
>>> Signed-off-by: Wenlin Kang <wenlin.kang@...driver.com>
>>> ---
>>>   drivers/mtd/mtd_blkdevs.c |    2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
>>> index 2b0c5287..f8bb16e 100644
>>> --- a/drivers/mtd/mtd_blkdevs.c
>>> +++ b/drivers/mtd/mtd_blkdevs.c
>>> @@ -273,7 +273,7 @@ static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
>>>   	if (!dev->mtd)
>>>   		goto unlock;
>>>   
>>> -	ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
>>> +	ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENXIO;
>> Good catch. I don't think ENXIO is correct in this case, though. Maybe
>> -EOPNOTSUPP or -ENOSYS? The latter might make more sense I guess.
>>
> I would recommend -EOPNOTSUPP as this as nothing to do with unimplemented
> functions or hardware support. This is just unsupported due to the value
> being NULL and therefore the hardware support is not there.
> Just My Option,
> Nick

As you said, -EOPNOTSUPP might be better,thanks.

Hi Brian

I have remade the patch and attached it, would you please check it 
again? thanks.

>>>   unlock:
>>>   	mutex_unlock(&dev->lock);
>>>   	blktrans_dev_put(dev);
>> Thanks,
>> Brian
>>
>> ______________________________________________________
>> Linux MTD discussion mailing list
>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>>
>

-- 
Thanks,
Wenlin Kang

View attachment "0001-mtd-blktrans-change-blktrans_getgeo-return-value.patch" of type "text/x-diff" (1217 bytes)

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