From fd383c2d3cae146337cea809de0d622b8b887e6c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 17:13:23 -0400 Subject: [PATCH] blkcg: implement task_get_blkcg_css() Implement a wrapper around task_get_css() to acquire the blkcg css for a given task. The wrapper is necessary for cgroup writeback support as there will be places outside blkcg proper trying to acquire blkcg_css and blkio_cgrp_id will be undefined when !CONFIG_BLK_CGROUP. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- include/linux/blk-cgroup.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 65f0c178fd04..4dc643f2046e 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -195,6 +195,12 @@ static inline struct blkcg *bio_blkcg(struct bio *bio) return task_blkcg(current); } +static inline struct cgroup_subsys_state * +task_get_blkcg_css(struct task_struct *task) +{ + return task_get_css(task, blkio_cgrp_id); +} + /** * blkcg_parent - get the parent of a blkcg * @blkcg: blkcg of interest @@ -573,6 +579,12 @@ struct blkcg_policy { #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) +static inline struct cgroup_subsys_state * +task_get_blkcg_css(struct task_struct *task) +{ + return NULL; +} + #ifdef CONFIG_BLOCK static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } -- 2.34.1