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Subject: Re: [PATCH RFC v3 for-6.8/block 04/17] mtd: block2mtd: use bdev apis
To: Jan Kara <jack@suse.cz>, Yu Kuai <yukuai1@huaweicloud.com>
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 <20240104112855.uci45hhqaiitmsir@quack3>
From: Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <b97810e9-c1bc-9198-c0d2-e132dde3e1f6@huaweicloud.com>
Date: Thu, 4 Jan 2024 20:22:34 +0800
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Hi,

?? 2024/01/04 19:28, Jan Kara д??:
> 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?

I think this is a great idea! And bdev_balance_dirty_pages_ratelimited()
can be removed as well.

Thanks,
Kuai

> 
> 								Honza
>