Re: [PATCH] btrfs: Use raw numbers when setting passing uptodate parameter to btrfs_writepage_endio_finish_ordered

[Anand Jain <anand.jain@oracle.com>]

On 3/21/19 11:25 PM, David Sterba wrote:
> On Thu, Mar 21, 2019 at 04:31:53PM +0200, Nikolay Borisov wrote:
>>
>>
>> On 21.03.19 г. 16:30 ч., David Sterba wrote:
>>> On Wed, Mar 20, 2019 at 09:53:16PM +0200, Nikolay Borisov wrote:
>>>> The uptodate parameter of btrfs_writepage_endio_finish_ordered is used
>>>> to signal whether an error has occured while writing the given page.
>>>> 0 signal an error, which is propagated to callees and 1 signifies
>>>> success. In end_compressed_bio_write the ->bi_status is checked and
>>>> based on it either BLK_STS_OK (0) or BLK_STS_NOTSUPP (1) are used. While
>>>> from functional point of view this is ok it's a for the poor reader of
>>>> the code, since the block layer values are conflated with the semantics
>>>> of the parameter.
>>>>
>>>> Just use plain 0 or 1. No functional changes.
>>>>
>>>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>>>> ---
>>>>   fs/btrfs/compression.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
>>>> index eb8e20b740d6..f82441f18512 100644
>>>> --- a/fs/btrfs/compression.c
>>>> +++ b/fs/btrfs/compression.c
>>>> @@ -250,7 +250,7 @@ static void end_compressed_bio_write(struct bio *bio)
>>>>   	cb->compressed_pages[0]->mapping = cb->inode->i_mapping;
>>>>   	btrfs_writepage_endio_finish_ordered(cb->compressed_pages[0],
>>>>   			cb->start, cb->start + cb->len - 1,
>>>> -			bio->bi_status ? BLK_STS_OK : BLK_STS_NOTSUPP);
>>>> +			bio->bi_status ? 0 : 1);
>>>
>>> Essentially reverting 2dbe0c77186c691386b74391039899808a4d3f59, but
>>> using the BLK_STS constants is definetelly wrong. The values match the
>>> intended use of 'uptodate', but otherwise are confusing.
>>>
>>> I actually think it can be simplified to bio->bi_staus == BLK_STS_OK.
>>
>> Yes that would work, are you going to fix up the patch or shall I resend?
> 
> I'll fix it.

bio->bi_staus == BLK_STS_OK ? 1 : 0);

Is better. Its confusing. Thanks for the fix.

Reviewed-by: Anand Jain <anand.jain@oracle.com>