diff options
| -rw-r--r-- | kernel/cgroup.c | 63 |
1 files changed, 58 insertions, 5 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 87167e40c4fa..fd684bfd154d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4426,6 +4426,60 @@ out_err: return ret; } +static void cgroup_procs_release(struct kernfs_open_file *of) +{ + if (of->priv) { + css_task_iter_end(of->priv); + kfree(of->priv); + } +} + +static void *cgroup_procs_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct kernfs_open_file *of = s->private; + struct css_task_iter *it = of->priv; + struct task_struct *task; + + do { + task = css_task_iter_next(it); + } while (task && !thread_group_leader(task)); + + return task; +} + +static void *cgroup_procs_start(struct seq_file *s, loff_t *pos) +{ + struct kernfs_open_file *of = s->private; + struct cgroup *cgrp = seq_css(s)->cgroup; + struct css_task_iter *it = of->priv; + + /* + * When a seq_file is seeked, it's always traversed sequentially + * from position 0, so we can simply keep iterating on !0 *pos. + */ + if (!it) { + if (WARN_ON_ONCE((*pos)++)) + return ERR_PTR(-EINVAL); + + it = kzalloc(sizeof(*it), GFP_KERNEL); + if (!it) + return ERR_PTR(-ENOMEM); + of->priv = it; + css_task_iter_start(&cgrp->self, it); + } else if (!(*pos)++) { + css_task_iter_end(it); + css_task_iter_start(&cgrp->self, it); + } + + return cgroup_procs_next(s, NULL, NULL); +} + +static int cgroup_procs_show(struct seq_file *s, void *v) +{ + seq_printf(s, "%d\n", task_tgid_vnr(v)); + return 0; +} + /* * Stuff for reading the 'tasks'/'procs' files. * @@ -4914,11 +4968,10 @@ static struct cftype cgroup_dfl_base_files[] = { { .name = "cgroup.procs", .file_offset = offsetof(struct cgroup, procs_file), - .seq_start = cgroup_pidlist_start, - .seq_next = cgroup_pidlist_next, - .seq_stop = cgroup_pidlist_stop, - .seq_show = cgroup_pidlist_show, - .private = CGROUP_FILE_PROCS, + .release = cgroup_procs_release, + .seq_start = cgroup_procs_start, + .seq_next = cgroup_procs_next, + .seq_show = cgroup_procs_show, .write = cgroup_procs_write, }, { |