From ec438699a9ae0856c2ce20a50dd39cdc7e92a732 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 17:13:22 -0400 Subject: cgroup, block: implement task_get_css() and use it in bio_associate_current() bio_associate_current() currently open codes task_css() and css_tryget_online() to find and pin $current's blkcg css. Abstract it into task_get_css() which is implemented from cgroup side. As a task is always associated with an online css for every subsystem except while the css_set update is propagating, task_get_css() retries till css_tryget_online() succeeds. This is a cleanup and shouldn't lead to noticeable behavior changes. Signed-off-by: Tejun Heo Cc: Li Zefan Cc: Jens Axboe Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/bio.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) (limited to 'block/bio.c') diff --git a/block/bio.c b/block/bio.c index 259197d..c4f8701 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2004,7 +2004,6 @@ EXPORT_SYMBOL(bioset_create_nobvec); int bio_associate_current(struct bio *bio) { struct io_context *ioc; - struct cgroup_subsys_state *css; if (bio->bi_ioc) return -EBUSY; @@ -2013,17 +2012,9 @@ int bio_associate_current(struct bio *bio) if (!ioc) return -ENOENT; - /* acquire active ref on @ioc and associate */ get_io_context_active(ioc); bio->bi_ioc = ioc; - - /* associate blkcg if exists */ - rcu_read_lock(); - css = task_css(current, blkio_cgrp_id); - if (css && css_tryget_online(css)) - bio->bi_css = css; - rcu_read_unlock(); - + bio->bi_css = task_get_css(current, blkio_cgrp_id); return 0; } -- cgit v1.1