On Mon, Jul 10, 2017 at 11:40:17AM -0700, Shaohua Li wrote:
> bio_free isn't a good place to free cgroup info. There are a
> lot of cases bio is allocated in special way (for example, in stack) and
> never gets called by bio_put hence bio_free, we are leaking memory. This
> patch moves the free to bio endio, which should be called anyway. The
> bio_uninit call in bio_free is kept, in case the bio never gets called
> bio endio.
>
> This assumes ->bi_end_io() doesn't access cgroup info, which seems true
> in my audit.
>
> This along with Christoph's integrity patch should fix the memory leak
> issue.
Can we please go ahead and:
(a) remove the now unneeded call in __blkdev_direct_IO_simple
(b) kill bio_uninit - it's just a wrapper around bio_disassociate_task
(c) check if we can remove the call in bio_free, which I think we can
as bi_ioc and bi_css are only assigned from generic_make_request
