diff options
| author | Tejun Heo <tj@kernel.org> | 2013-06-25 11:53:37 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-06-25 11:53:37 -0700 |
| commit | fc76df706123602214da494ba98bccea83e2cfff (patch) | |
| tree | 27ff818b65d9c2866ba1caee3c739ec9f9232337 | |
| parent | 30159ec7a9db7f3c91e2b27e66389c49302efd5c (diff) | |
cgroup: reserve ID 0 for dummy_root and 1 for unified hierarchy
Before 1a57423166 ("cgroup: make hierarchy_id use cyclic idr"),
hierarchy IDs were allocated from 0. As the dummy hierarchy was
always the one first initialized, it got assigned 0 and all other
hierarchies from 1. The patch accidentally changed the minimum
useable ID to 2.
Let's restore ID 0 for dummy_root and while at it reserve 1 for
unified hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
| -rw-r--r-- | kernel/cgroup.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index cef688128fb8..f9c99abc38ab 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1425,14 +1425,15 @@ static void init_cgroup_root(struct cgroupfs_root *root) init_cgroup_housekeeping(cgrp); } -static int cgroup_init_root_id(struct cgroupfs_root *root) +static int cgroup_init_root_id(struct cgroupfs_root *root, int start, int end) { int id; lockdep_assert_held(&cgroup_mutex); lockdep_assert_held(&cgroup_root_mutex); - id = idr_alloc_cyclic(&cgroup_hierarchy_idr, root, 2, 0, GFP_KERNEL); + id = idr_alloc_cyclic(&cgroup_hierarchy_idr, root, start, end, + GFP_KERNEL); if (id < 0) return id; @@ -1635,7 +1636,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if (ret) goto unlock_drop; - ret = cgroup_init_root_id(root); + /* ID 0 is reserved for dummy root, 1 for unified hierarchy */ + ret = cgroup_init_root_id(root, 2, 0); if (ret) goto unlock_drop; @@ -4898,7 +4900,7 @@ int __init cgroup_init(void) key = css_set_hash(init_css_set.subsys); hash_add(css_set_table, &init_css_set.hlist, key); - BUG_ON(cgroup_init_root_id(&cgroup_dummy_root)); + BUG_ON(cgroup_init_root_id(&cgroup_dummy_root, 0, 1)); mutex_unlock(&cgroup_root_mutex); mutex_unlock(&cgroup_mutex); |