From 5faaf05f2976fd9ec0ecd582bcfb3a41cde4c65e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 26 Apr 2018 14:29:04 -0700 Subject: cgroup: Explicitly remove core interface files The "cgroup." core interface files bypass the usual interface removal path and get removed recursively along with the cgroup itself. While this works now, the subtle discrepancy gets in the way of implementing common mechanisms. This patch updates cgroup core interface file handling so that it's consistent with controller interface files. When added, the css is marked CSS_VISIBLE and they're explicitly removed before the cgroup is destroyed. This doesn't cause user-visible behavior changes. Signed-off-by: Tejun Heo --- kernel/cgroup/cgroup.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index a662bfcbea0e..25309c868728 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1573,8 +1573,17 @@ static void css_clear_dir(struct cgroup_subsys_state *css) css->flags &= ~CSS_VISIBLE; - list_for_each_entry(cfts, &css->ss->cfts, node) + if (!css->ss) { + if (cgroup_on_dfl(cgrp)) + cfts = cgroup_base_files; + else + cfts = cgroup1_base_files; + cgroup_addrm_files(css, cgrp, cfts, false); + } else { + list_for_each_entry(cfts, &css->ss->cfts, node) + cgroup_addrm_files(css, cgrp, cfts, false); + } } /** @@ -1598,14 +1607,16 @@ static int css_populate_dir(struct cgroup_subsys_state *css) else cfts = cgroup1_base_files; - return cgroup_addrm_files(&cgrp->self, cgrp, cfts, true); - } - - list_for_each_entry(cfts, &css->ss->cfts, node) { - ret = cgroup_addrm_files(css, cgrp, cfts, true); - if (ret < 0) { - failed_cfts = cfts; - goto err; + ret = cgroup_addrm_files(&cgrp->self, cgrp, cfts, true); + if (ret < 0) + return ret; + } else { + list_for_each_entry(cfts, &css->ss->cfts, node) { + ret = cgroup_addrm_files(css, cgrp, cfts, true); + if (ret < 0) { + failed_cfts = cfts; + goto err; + } } } @@ -5090,10 +5101,8 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) for_each_css(css, ssid, cgrp) kill_css(css); - /* - * Remove @cgrp directory along with the base files. @cgrp has an - * extra ref on its kn. - */ + /* clear and remove @cgrp dir, @cgrp has an extra ref on its kn */ + css_clear_dir(&cgrp->self); kernfs_remove(cgrp->kn); if (parent && cgroup_is_threaded(cgrp)) -- cgit v1.2.3