diff options
| -rw-r--r-- | kernel/cgroup.c | 77 |
1 files changed, 47 insertions, 30 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 97cb1315bcac..1193038d0729 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3013,6 +3013,49 @@ static bool cgroup_drain_offline(struct cgroup *cgrp) } /** + * cgroup_apply_control_enable - enable or show csses according to control + * @cgrp: parent of the target cgroups + * + * Walk @cgrp's children and create new csses or make the existing ones + * visible. A css is created invisible if it's being implicitly enabled + * through dependency. An invisible css is made visible when the userland + * explicitly enables it. + * + * Returns 0 on success, -errno on failure. On failure, csses which have + * been processed already aren't cleaned up. The caller is responsible for + * cleaning up with cgroup_apply_control_disble(). + */ +static int cgroup_apply_control_enable(struct cgroup *cgrp) +{ + struct cgroup *dsct; + struct cgroup_subsys *ss; + int ssid, ret; + + cgroup_for_each_live_child(dsct, cgrp) { + for_each_subsys(ss, ssid) { + struct cgroup_subsys_state *css = cgroup_css(dsct, ss); + + if (!(cgroup_ss_mask(dsct) & (1 << ss->id))) + continue; + + if (!css) { + css = css_create(dsct, ss); + if (IS_ERR(css)) + return PTR_ERR(css); + } + + if (cgroup_control(dsct) & (1 << ss->id)) { + ret = css_populate_dir(css, NULL); + if (ret) + return ret; + } + } + } + + return 0; +} + +/** * cgroup_apply_control_disable - kill or hide csses according to control * @cgrp: parent of the target cgroups * @@ -3157,36 +3200,10 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, cgrp->subtree_control = new_sc; cgrp->subtree_ss_mask = new_ss; - /* - * Create new csses or make the existing ones visible. A css is - * created invisible if it's being implicitly enabled through - * dependency. An invisible css is made visible when the userland - * explicitly enables it. - */ - do_each_subsys_mask(ss, ssid, enable) { - cgroup_for_each_live_child(child, cgrp) { - if (css_enable & (1 << ssid)) { - struct cgroup_subsys_state *css; - - css = css_create(child, ss); - if (IS_ERR(css)) { - ret = PTR_ERR(css); - goto err_undo_css; - } - - if (cgrp->subtree_control & (1 << ssid)) { - ret = css_populate_dir(css, NULL); - if (ret) - goto err_undo_css; - } - } else { - ret = css_populate_dir(cgroup_css(child, ss), - NULL); - if (ret) - goto err_undo_css; - } - } - } while_each_subsys_mask(); + /* prepare csses */ + ret = cgroup_apply_control_enable(cgrp); + if (ret) + goto err_undo_css; /* * At this point, cgroup_e_css() results reflect the new csses |