Re: [PATCH 03/13] blkcg: convert blkg_lookup_create() to find closest blkg

From: Josef Bacik
Date: Tue Nov 27 2018 - 16:01:39 EST

On Mon, Nov 26, 2018 at 04:19:36PM -0500, Dennis Zhou wrote:
> There are several scenarios where blkg_lookup_create() can fail such as
> the blkcg dying, request_queue is dying, or simply being OOM. Most
> handle this by simply falling back to the q->root_blkg and calling it a
> day.
> This patch implements the notion of closest blkg. During
> blkg_lookup_create(), if it fails to create, return the closest blkg
> found or the q->root_blkg. blkg_try_get_closest() is introduced and used
> during association so a bio is always attached to a blkg.
> Signed-off-by: Dennis Zhou <dennis@xxxxxxxxxx>
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>