Subject: Re: [PATCH] mmc: block: remove the check for whole block device for
 ioctl.
To: Christoph Hellwig <hch@infradead.org>
References: <1458055567-27878-1-git-send-email-fengwei.yin@linaro.org>
 <20160315143101.GA19497@infradead.org>
Cc: jonathanh@nvidia.com, ulf.hansson@linaro.org, linux-kernel@vger.kernel.org
From: "fengwei.yin" <fengwei.yin@linaro.org>
Message-ID: <56E89E75.3080001@linaro.org>
Date: Wed, 16 Mar 2016 07:44:53 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.6.0
MIME-Version: 1.0
In-Reply-To: <20160315143101.GA19497@infradead.org>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1081
Lines: 32


On 2016/3/15 22:31, Christoph Hellwig wrote:
> On Tue, Mar 15, 2016 at 11:26:07AM -0400, Yin, Fengwei wrote:
>> From: Fengwei Yin <fengwei.yin@linaro.org>
>>
>> a5f5774c55a2e3ed75f4d6c5556b7bfcb726e6f0 introduced the whole block
>> device checking for MMC_IOC_CMD while the old code has no such check.
>>
>> It breaks some ioctl call like BLKROSET from user space. An example
>> is "adb remount" cmd. It prints out following error message:
>> "remount of /system failed; couldn't make block device XXXX writable: \
>> Operation not permitted."
>> while the command worked fine.
>>
>> This change move the whole block device checking only for MMC_IOC_MULTI_CMD.
>
> I think mmc_blk_ioctl_cmd will need this as well, as will probably
> do any new ioctl.
>
> So I think the right fix is to simply return -EINVAL instead of
> EPERM if on a partition, which will make all the block layer ioctls
> works fine.
Fair enough.

I will wait for one more day for further comments to the patch. And update
the patch tomorrow. Thanks a lot for looking into the patch.

Regards
Yin, Fengwei

>