diff options
| author | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:14 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:14 -0400 |
| commit | ddfcadab35dda6e5bc23ccf1c3055ecb63a71e49 (patch) | |
| tree | 68ff0218d96629b63d30a3a91580bff256f93c28 /kernel/cgroup.c | |
| parent | a2bed8209a3afc3b2cf1c28383fb48155c1fea46 (diff) | |
cgroup: update init_css() into init_and_link_css()
init_css() takes the cgroup the new css belongs to as an argument and
initializes the new css's ->cgroup and ->parent pointers but doesn't
acquire the matching reference counts. After the previous patch,
create_css() puts init_css() and reference acquisition right next to
each other. Let's move reference acquistion into init_css() and
rename the function to init_and_link_css(). This makes sense and is
easier to follow. This makes the root csses to hold a reference on
cgrp_dfl_root.cgrp, which is harmless.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 0e2c401ed7b9..f1c98c527b2d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4109,17 +4109,21 @@ static void css_release(struct percpu_ref *ref) call_rcu(&css->rcu_head, css_free_rcu_fn); } -static void init_css(struct cgroup_subsys_state *css, struct cgroup_subsys *ss, - struct cgroup *cgrp) +static void init_and_link_css(struct cgroup_subsys_state *css, + struct cgroup_subsys *ss, struct cgroup *cgrp) { + cgroup_get(cgrp); + css->cgroup = cgrp; css->ss = ss; css->flags = 0; - if (cgrp->parent) + if (cgrp->parent) { css->parent = cgroup_css(cgrp->parent, ss); - else + css_get(css->parent); + } else { css->flags |= CSS_ROOT; + } BUG_ON(cgroup_css(cgrp, ss)); } @@ -4185,9 +4189,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss) if (IS_ERR(css)) return PTR_ERR(css); - init_css(css, ss, cgrp); - cgroup_get(cgrp); - css_get(css->parent); + init_and_link_css(css, ss, cgrp); err = percpu_ref_init(&css->refcnt, css_release); if (err) @@ -4656,7 +4658,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) css = ss->css_alloc(cgroup_css(&cgrp_dfl_root.cgrp, ss)); /* We don't handle early failures gracefully */ BUG_ON(IS_ERR(css)); - init_css(css, ss, &cgrp_dfl_root.cgrp); + init_and_link_css(css, ss, &cgrp_dfl_root.cgrp); /* Update the init_css_set to contain a subsys * pointer to this state - since the subsystem is |