cgroup: factor out cgroup_apply_control_enable() from cgroup_subtree_control_write() (bdb53bd7) · Commits · 戴 / test

kernel/cgroup.c

+47 −30

Original line number	Diff line number	Diff line
		@@ -3012,6 +3012,49 @@ static bool cgroup_drain_offline(struct cgroup *cgrp)
		return false;
		}

		/**
		* 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);
		/* prepare csses */
		ret = cgroup_apply_control_enable(cgrp);
		if (ret)
		goto err_undo_css;
		}
		}
		} while_each_subsys_mask();

		/*
		* At this point, cgroup_e_css() results reflect the new csses

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