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authorShaohua Li <shli@fb.com>2017-09-14 14:02:06 -0700
committerJens Axboe <axboe@kernel.dk>2017-09-26 07:41:22 -0600
commit902ec5b6de0678ac2effba0faaafdd1c3e7fcf2e (patch)
tree1e3c7ab62c68cd37e81a13f46bceba374c5ea5ae
parentblkcg: delete unused APIs (diff)
downloadlinux-dev-902ec5b6de0678ac2effba0faaafdd1c3e7fcf2e.tar.xz
linux-dev-902ec5b6de0678ac2effba0faaafdd1c3e7fcf2e.zip
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 <tj@kernel.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--include/linux/blk-cgroup.h13
1 files changed, 7 insertions, 6 deletions
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 0cfa8d2ef4d6..f57e54d64529 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -19,6 +19,7 @@
#include <linux/radix-tree.h>
#include <linux/blkdev.h>
#include <linux/atomic.h>
+#include <linux/kthread.h>
/* 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));
}
/**