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Date: Thu, 4 Jan 2024 12:28:55 +0100
From: Jan Kara <jack@suse.cz>
To: Yu Kuai <yukuai1@huaweicloud.com>
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Subject: Re: [PATCH RFC v3 for-6.8/block 04/17] mtd: block2mtd: use bdev apis
Message-ID: <20240104112855.uci45hhqaiitmsir@quack3>
References: <20231221085712.1766333-1-yukuai1@huaweicloud.com>
 <20231221085712.1766333-5-yukuai1@huaweicloud.com>
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In-Reply-To: <20231221085712.1766333-5-yukuai1@huaweicloud.com>

On Thu 21-12-23 16:56:59, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> On the one hand covert to use folio while reading bdev inode, on the
> other hand prevent to access bd_inode directly.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
...
> +		for (p = folio_address(folio); p < max; p++)
>  			if (*p != -1UL) {
> -				lock_page(page);
> -				memset(page_address(page), 0xff, PAGE_SIZE);
> -				set_page_dirty(page);
> -				unlock_page(page);
> -				balance_dirty_pages_ratelimited(mapping);
> +				folio_lock(folio);
> +				memset(folio_address(folio), 0xff,
> +				       folio_size(folio));
> +				folio_mark_dirty(folio);
> +				folio_unlock(folio);
> +				bdev_balance_dirty_pages_ratelimited(bdev);

Rather then creating this bdev_balance_dirty_pages_ratelimited() just for
MTD perhaps we can have here (and in other functions):

				...
				mapping = folio_mapping(folio);
				folio_unlock(folio);
				if (mapping)
					balance_dirty_pages_ratelimited(mapping);

What do you think? Because when we are working with the folios it is rather
natural to use their mapping for dirty balancing?

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR