Re: Bug_ON with patch: bio: modify __bio_add_page() to accept pages that don't start a new segment

[Maurizio Lombardi <mlombard@redhat.com>]

Hi,

On 07/15/2014 10:44 AM, Maurizio Lombardi wrote:
>> I have reverted it yesterday in my tree. 
>>
> 
> 
> The problem was here:
> 
>         if (q->merge_bvec_fn) {
>                 struct bvec_merge_data bvm = {
>                         .bi_bdev = bio->bi_bdev,
>                         .bi_sector = bio->bi_iter.bi_sector,
>                         .bi_size = bio->bi_iter.bi_size, <-------
>                         .bi_rw = bio->bi_rw,
>                 };
> 
>                 /*
>                  * merge_bvec_fn() returns number of bytes it can accept
>                  * at this offset
>                  */
>                 if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len)
>                         goto failed;
>         }
> 
>         /* If we may be able to merge these biovecs, force a recount */
>         if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
>                 bio->bi_flags &= ~(1 << BIO_SEG_VALID);
> 
> 
> it should have been ".bi_size = bio->bi_iter.bi_size - len"
> 

Jens, will you restore the patch in your tree if I submit
this fix?

Thanks,
Maurizio Lombardi