From 7a6d305114ffc0ade15ff8c5fa6bc185f70fb182 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Thu, 14 Sep 2017 14:02:06 -0700 Subject: [PATCH] block: make blkcg aware of kthread stored original cgroup info bio_blkcg is the only API to get cgroup info for a bio right now. If bio_blkcg finds current task is a kthread and has original blkcg associated, it will use the css instead of associating the bio to current task. This makes it possible that kthread dispatches bios on behalf of other threads. Acked-by: Tejun Heo Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- include/linux/blk-cgroup.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 0cfa8d2ef4d63..f57e54d645297 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -19,6 +19,7 @@ #include #include #include +#include /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) @@ -223,16 +224,16 @@ static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) return css ? container_of(css, struct blkcg, css) : NULL; } -static inline struct blkcg *task_blkcg(struct task_struct *tsk) -{ - return css_to_blkcg(task_css(tsk, io_cgrp_id)); -} - static inline struct blkcg *bio_blkcg(struct bio *bio) { + struct cgroup_subsys_state *css; + if (bio && bio->bi_css) return css_to_blkcg(bio->bi_css); - return task_blkcg(current); + css = kthread_blkcg(); + if (css) + return css_to_blkcg(css); + return css_to_blkcg(task_css(current, io_cgrp_id)); } /** -- 2.39.5