cgroups: add inactive subsystems to rootnode.subsys_list (33a68ac1) · Commits · 戴 / test

Though for an inactive hierarchy, we have subsys->root == &rootnode, but rootnode's subsys_list is always empty. This conflicts with the code in find_css_set(): for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { ... if (ss->root->subsys_list.next == &ss->sibling) { ... } } if (list_empty(&rootnode.subsys_list)) { ... } The above code assumes rootnode.subsys_list links all inactive hierarchies. Signed-off-by:

Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -712,7 +712,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
		BUG_ON(dummytop->subsys[i]->cgroup != dummytop);
		cgrp->subsys[i] = dummytop->subsys[i];
		cgrp->subsys[i]->cgroup = cgrp;
		list_add(&ss->sibling, &root->subsys_list);
		list_move(&ss->sibling, &root->subsys_list);
		ss->root = root;
		if (ss->bind)
		ss->bind(ss, cgrp);
		@@ -726,7 +726,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
		dummytop->subsys[i]->cgroup = dummytop;
		cgrp->subsys[i] = NULL;
		subsys[i]->root = &rootnode;
		list_del(&ss->sibling);
		list_move(&ss->sibling, &rootnode.subsys_list);
		} else if (bit & final_bits) {
		/* Subsystem state should already exist */
		BUG_ON(!cgrp->subsys[i]);
		@@ -2521,6 +2521,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
		printk(KERN_INFO "Initializing cgroup subsys %s\n", ss->name);

		/* Create the top cgroup state for this subsystem */
		list_add(&ss->sibling, &rootnode.subsys_list);
		ss->root = &rootnode;
		css = ss->create(ss, dummytop);
		/* We don't handle early failures gracefully */

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