diff options
| author | Tejun Heo <tj@kernel.org> | 2022-08-19 13:50:23 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2022-08-19 13:50:23 -1000 |
| commit | b3a0dc646ab7718099d2a3b03285a2bd1f539ab6 (patch) | |
| tree | 09044822434a2123254a6559ebef0b2bff158cb1 | |
| parent | 5a44f6fff9b38351661265e85958f41d4f4067e7 (diff) | |
| download | misc-kernfs-deactivate.tar.gz | |
cgroup: Implement cgroup_file_show()kernfs-deactivate
Add cgroup_file_show() which allows toggling visibility of a cgroup file
using the new kernfs_deactivate(). This will be used to hide psi interface
files on cgroups where it's disabled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
| -rw-r--r-- | include/linux/cgroup.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 23 |
2 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index ed53bfe7c46c47..f61dd135efbebb 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -114,6 +114,7 @@ int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_rm_cftypes(struct cftype *cfts); void cgroup_file_notify(struct cgroup_file *cfile); +void cgroup_file_show(struct cgroup_file *cfile, bool show); int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index ffaccd6373f1e7..eb096499c72bc2 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4340,6 +4340,29 @@ void cgroup_file_notify(struct cgroup_file *cfile) } /** + * cgroup_file_show - show or hide a hidden cgroup file + * @cfile: target cgroup_file obtained by setting cftype->file_offset + * @show: whether to show or hide + */ +void cgroup_file_show(struct cgroup_file *cfile, bool show) +{ + struct kernfs_node *kn; + + spin_lock_irq(&cgroup_file_kn_lock); + kn = cfile->kn; + kernfs_get(kn); + spin_unlock_irq(&cgroup_file_kn_lock); + + if (show) + kernfs_activate(kn); + else + kernfs_deactivate(kn); + + kernfs_put(kn); +} + + +/** * css_next_child - find the next child of a given css * @pos: the current position (%NULL to initiate traversal) * @parent: css whose children to walk |