Re: [PATCH] btrfs: replace a wrong memset() with memzero_page()

[Qu Wenruo <wqu@suse.com>]

On 2022/3/26 00:38, Christoph Hellwig wrote:
> On Fri, Mar 25, 2022 at 05:37:59PM +0800, Qu Wenruo wrote:
>> -	u32 len = fs_info->sectorsize;
>> +	const u32 len = fs_info->sectorsize;
> 
> Why the spurious and rather pointless const annotation that is unrelated
> to the rest of the patch?

Because we prefer const for constant variables in btrfs code.

As we have experienced some bugs in the past related to reusing some 
variables.

> 
>>   					     BTRFS_DEV_STAT_CORRUPTION_ERRS);
>> -	memset(kaddr + pgoff, 1, len);
>> +	memzero_page(page, pgoff, len);
>>   	flush_dcache_page(page);
> 
> memzero_page already takes care of the flush_dcache_page.
> 

Oh, indeed.

Thanks,
Qu