bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case
authorYafang Shao <laoar.shao@gmail.com>
Wed, 6 Dec 2023 11:53:24 +0000 (11:53 +0000)
committerMartin KaFai Lau <martin.lau@kernel.org>
Sat, 9 Dec 2023 01:08:18 +0000 (17:08 -0800)
commit73d9eb340d2b95e0e86a656a7f3157c137f10129
treea442aeae6b760b983992eda002e9adce995eea10
parent1720c42b90c8f14ffcb2f2f39a1abafc82a5b22e
bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case

In the current cgroup1 environment, associating operations between cgroups
and applications in a BPF program requires storing a mapping of cgroup_id
to application either in a hash map or maintaining it in userspace.
However, by enabling bpf_cgrp_storage for cgroup1, it becomes possible to
conveniently store application-specific information in cgroup-local storage
and utilize it within BPF programs. Furthermore, enabling this feature for
cgroup1 involves minor modifications for the non-attach case, streamlining
the process.

However, when it comes to enabling this functionality for the cgroup1
attach case, it presents challenges. Therefore, the decision is to focus on
enabling it solely for the cgroup1 non-attach case at present. If
attempting to attach to a cgroup1 fd, the operation will simply fail with
the error code -EBADF.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231206115326.4295-2-laoar.shao@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel/bpf/bpf_cgrp_storage.c