[PATCH 13/14] cgroup: move subsys file removal to kill_css()
From: Tejun Heo <hidden>
Date: 2013-08-08 20:14:31
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
With the planned unified hierarchy, individual css's will be created and destroyed dynamically across the lifetime of a cgroup. To enable such usages, css destruction is being decoupled from cgroup destruction. This patch moves subsys file removal from cgroup_destroy_locked() to kill_css(). While this changes the order of destruction operations, the changes shouldn't be noticeable to cgroup subsystems or userland. Signed-off-by: Tejun Heo <redacted> --- kernel/cgroup.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index da5f5c2..d99ec53 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c@@ -4595,13 +4595,15 @@ static void css_killed_ref_fn(struct percpu_ref *ref) * kill_css - destroy a css * @css: css to destroy * - * This function initiates destruction of @css by putting its base - * reference. ->css_offline() will be invoked asynchronously once - * css_tryget() is guaranteed to fail and when the reference count reaches - * zero, @css will be released. + * This function initiates destruction of @css by removing cgroup interface + * files and putting its base reference. ->css_offline() will be invoked + * asynchronously once css_tryget() is guaranteed to fail and when the + * reference count reaches zero, @css will be released. */ static void kill_css(struct cgroup_subsys_state *css) { + cgroup_clear_dir(css->cgroup, 1 << css->ss->subsys_id); + /* * Killing would put the base ref, but we need to keep it alive * until after ->css_offline().
@@ -4699,10 +4701,10 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) cgroup_destroy_css_killed(cgrp); /* - * Clear and remove @cgrp directory. The removal puts the base ref - * but we aren't quite done with @cgrp yet, so hold onto it. + * Clear the base files and remove @cgrp directory. The removal + * puts the base ref but we aren't quite done with @cgrp yet, so + * hold onto it. */ - cgroup_clear_dir(cgrp, cgrp->root->subsys_mask); cgroup_addrm_files(cgrp, cgroup_base_files, false); dget(d); cgroup_d_remove_dir(d);
--
1.8.3.1