Re: [PATCH] block: move sanity checking ahead of bi_front/back_seg_size updating

[jianchao.wang]

On 09/19/2017 07:51 AM, Christoph Hellwig wrote:
> On Sat, Sep 16, 2017 at 07:10:30AM +0800, Jianchao Wang wrote:
>> If the bio_integrity_merge_rq() return false or nr_phys_segments exceeds
>> the max_segments, the merging fails, but the bi_front/back_seg_size may
>> have been modified. To avoid it, move the sanity checking ahead.
>>
>> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
> 
> This looks fine to me:
> 
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> 
> But can you elaborate a little more on how this found and if there
> is a way to easily reproduce it, say for a blktests test case?
> 
It is found when I made the patch of 
'block: consider merge of segments when merge bio into rq' , not from an actual
issue or test case.

Thanks
Jianchao