Re: [PATCH] bio allocation failure due to bio_get_nr_vecs()

Jens Axboe
2012-05-11T14:46:04Z

On 05/11/2012 04:44 PM, Bernd Schubert wrote:
> On 05/11/2012 04:36 PM, Jens Axboe wrote:
>> On 05/11/2012 03:49 PM, Bernd Schubert wrote:
>>> The number of bio_get_nr_vecs() is passed down via bio_alloc() to
>>> bvec_alloc_bs(), which fails the bio allocation if
>>> nr_iovecs> BIO_MAX_PAGES. For the underlying caller this causes an
>>> unexpected bio allocation failure.
>>> Limiting to queue_max_segments() is not sufficient, as max_segments
>>> also might be very large.
>>>
>>> bvec_alloc_bs(gfp_mask, nr_iovecs, ) => NULL when nr_iovecs> BIO_MAX_PAGES
>>> bio_alloc_bioset(gfp_mask, nr_iovecs, ...)
>>> bio_alloc(GFP_NOIO, nvecs)
>>> xfs_alloc_ioend_bio()
>>
>> Thanks, looks sane. Applied.
>>
>
> Great, thanks! Should we CC linux-stable for commit
> 5abebfdd02450fa1349daacf242e70b3736581e3 and this one, as I got a hard
> kernel panic?

Yes, that's a good idea. I've ammended the commit now to include stable.

--
Jens Axboe