From 33a68ac1c1b695216e873ee12e819adbe73e4d9f Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 7 Jan 2009 18:07:42 -0800 Subject: [PATCH] cgroups: add inactive subsystems to rootnode.subsys_list 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 Cc: Paul Menage Cc: KAMEZAWA Hiroyuki Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index fd572d057691..abf7248f501a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -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 */