[RFC PATCH bpf-next 6/9] cgroup: add v1 support to cgroup_get_from_id()
From: Yosry Ahmed <hidden>
Date: 2022-05-10 00:19:42
Also in:
bpf, cgroups, lkml
Subsystem:
control group (cgroup), the rest · Maintainers:
Tejun Heo, Johannes Weiner, Michal Koutný, Linus Torvalds
The current implementation of cgroup_get_from_id() only searches the default hierarchy for the given id. Make it compatible with cgroup v1 by looking through all the roots instead. cgrp_dfl_root should be the first element in the list so there shouldn't be a performance impact for cgroup v2 users (in the case of a valid id). Signed-off-by: Yosry Ahmed <redacted> --- kernel/cgroup/cgroup.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index af703cfcb9d2..12700cd21973 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c@@ -5970,10 +5970,16 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) */ struct cgroup *cgroup_get_from_id(u64 id) { - struct kernfs_node *kn; + struct kernfs_node *kn = NULL; struct cgroup *cgrp = NULL; + struct cgroup_root *root; + + for_each_root(root) { + kn = kernfs_find_and_get_node_by_id(root->kf_root, id); + if (kn) + break; + } - kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id); if (!kn) goto out;
--
2.36.0.512.ge40c2bad7a-goog