Hello, Waiman. On Tue, Jul 18, 2017 at 03:32:16PM -0400, Waiman Long wrote: > It was found that when a cgroup2 filesystem was mounted, control > files other than the base cgroup.* ones were not shown in the root > directory. They were shown only after some controllers were activated > in the root's cgroup.subtree_control file. > > This was caused by a lack of the kernfs_activate() call which was fixed > by this patch. > > Signed-off-by: Waiman Long <[email protected]> > --- > kernel/cgroup/cgroup.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c > index 89a23c6..fb1893b 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -2024,8 +2024,10 @@ static struct dentry *cgroup_mount(struct > file_system_type *fs_type, > > dentry = cgroup_do_mount(&cgroup2_fs_type, flags, > &cgrp_dfl_root, > CGROUP2_SUPER_MAGIC, ns); > - if (!IS_ERR(dentry)) > + if (!IS_ERR(dentry)) { > apply_cgroup_root_flags(root_flags); > + kernfs_activate(cgrp_dfl_root.cgrp.kn); > + }
Heh, that's tricky. I'm not quite sure where the unactivated files are being added tho because that'd be where we should be activating. I *think* that they are already activated as part of cgroup_add_cftypes() but I am obviously qmissing something. I'll try to repro the issue and find where we're skipping the activation call. Thanks! -- tejun
