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

[Christoph Hellwig]

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?