On 2020/11/19 上午4:27, David Sterba wrote:
> On Fri, Nov 13, 2020 at 08:51:29PM +0800, Qu Wenruo wrote:
>> Introduce a new helper, endio_readpage_release_extent(), to handle
>> update status update in end_bio_extent_readpage().
>>
>> The refactor itself is not really nothing interesting, the point here is
>> to provide the basis for later subpage support, where the page status
>> update can be more complex than current code.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  fs/btrfs/extent_io.c | 17 ++++++++++++-----
>>  1 file changed, 12 insertions(+), 5 deletions(-)
>>
>> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
>> index b5b3700943e0..caafe44542e8 100644
>> --- a/fs/btrfs/extent_io.c
>> +++ b/fs/btrfs/extent_io.c
>> @@ -2849,6 +2849,17 @@ endio_readpage_release_extent(struct processed_extent *processed,
>>  	processed->uptodate = uptodate;
>>  }
>>  
>> +static void endio_readpage_update_page_status(struct page *page, bool uptodate)
>> +{
>> +	if (uptodate) {
>> +		SetPageUptodate(page);
>> +	} else {
>> +		ClearPageUptodate(page);
>> +		SetPageError(page);
>> +	}
>> +	unlock_page(page);
> 
> That would be better left in the caller as it's quite important
> information but the helper name does not say anything about it.
> 

It may be the case for now, but for incoming subpage, check the patch
"btrfs: integrate page status update for read path into
begin/end_page_read()" to see why we want page unlocking to be done here.

Thanks,
Qu