Re: [PATCH BUGFIX V2] block: add missing group association in bio-cloning functions

From: Tejun Heo
Date: Tue May 10 2016 - 17:03:57 EST


On Tue, May 10, 2016 at 11:02:12PM +0200, Paolo Valente wrote:
> When a bio is cloned, the newly created bio must be associated with
> the same blkcg as the original bio (if BLK_CGROUP is enabled). If
> this operation is not performed, then the new bio is not associated
> with any group, and the group of the current task is returned when
> the group of the bio is requested.
>
> Depending on the cloning frequency, this may cause a large
> percentage of the bios belonging to a given group to be treated
> as if belonging to other groups (in most cases as if belonging to
> the root group). The expected group isolation may thereby be broken.
>
> This commit adds the missing association in bio-cloning functions.
>
> Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

--
tejun