On 7/1/19 8:05 AM, Jens Axboe wrote:
> On 7/1/19 1:14 AM, Ming Lei wrote:
>> 'bio->bi_iter.bi_size' is 'unsigned int', which at most hold 4G - 1
>> bytes.
>>
>> Before 07173c3ec276 ("block: enable multipage bvecs"), one bio can
>> include very limited pages, and usually at most 256, so the fs bio
>> size won't be bigger than 1M bytes most of times.
>>
>> Since we support multi-page bvec, in theory one fs bio really can
>> be added > 1M pages, especially in case of hugepage, or big writeback
>> with too many dirty pages. Then there is chance in which .bi_size
>> is overflowed.
>>
>> Fixes this issue by using bio_full() to check if the added segment may
>> overflow .bi_size.
>
> Any objections to queuing this up for 5.3? It's not a new regression
> this series.
I took a closer look, and applied for 5.3 and removed the stable tag.
We'll need to apply your patch for stable, and I added an adapted
one for 5.3. I don't want a huge merge hassle because of this.
--
Jens Axboe
