Re: [PATCH v5 2/5] mmc: block: Support alternative_gpt_sector() operation

From: Dmitry Osipenko <digetx@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Micha?? Miros??aw <mirq-linux@rere.qmqm.pl>,
	David Heidelberg <david@ixit.cz>,
	Peter Geis <pgwipeout@gmail.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Rob Herring <robh+dt@kernel.org>, Ion Agorria <AG0RRIA@yahoo.com>,
	Svyatoslav Ryhel <clamor95@gmail.com>,
	linux-tegra@vger.kernel.org, linux-block@vger.kernel.org,
	linux-efi <linux-efi@vger.kernel.org>
Subject: Re: [PATCH v5 2/5] mmc: block: Support alternative_gpt_sector() operation
Date: Wed, 18 Aug 2021 08:40:17 +0300	[thread overview]
Message-ID: <32a009f6-7357-27cc-20e3-247de6f7d786@gmail.com> (raw)
In-Reply-To: <YRyagtKThKYK+Eah@infradead.org>

18.08.2021 08:28, Christoph Hellwig пишет:
> On Wed, Aug 18, 2021 at 03:55:44AM +0300, Dmitry Osipenko wrote:
>> +static int mmc_blk_alternative_gpt_sector(struct block_device *bdev,
>> +					  sector_t *sector)
>> +{
>> +	struct mmc_card *card = mmc_bdev_to_card(bdev);
>> +
>> +	if (!card)
>> +		return -ENODEV;
>> +
>> +	if (!card->host->ops->alternative_gpt_sector)
>> +		return -EOPNOTSUPP;
>> +
>> +	return card->host->ops->alternative_gpt_sector(card, sector);
>> +}
>> +
> 
>> +static struct mmc_card *mmc_bdev_to_card(struct block_device *bdev)
>> +{
>> +	struct mmc_blk_data *md;
>> +
>> +	if (bdev->bd_disk->fops != &mmc_bdops)
>> +		return NULL;
> 
> No need for this check bow that it is only called through mmc_bdops.

Alright

>> +
>> +	md = mmc_blk_get(bdev->bd_disk);
>> +	if (!md)
>> +		return NULL;
>> +
>> +	return md->queue.card;
>> +}
> 
> This reference seems to never be dropped anywhere.
> 

Indeed, I missed that it bumps the refcnt.