[bpf-next,0/3] bpf: Expand bpf_cgrp_storage to support cgroup1 non-attach case

Message

Yafang Shao Dec. 6, 2023, 11:53 a.m. UTC

In the current cgroup1 environment, associating operations between a cgroup
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.

Changes:
- RFC -> v1:
  - Collect acked-by
  - Avoid unnecessary is_cgroup1 check (Yonghong)
  - Keep the code patterns consistent (Yonghong)

Yafang Shao (3):
  bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case
  selftests/bpf: Add a new cgroup helper open_classid()
  selftests/bpf: Add selftests for cgroup1 local storage

 kernel/bpf/bpf_cgrp_storage.c                      |  6 +-
 tools/testing/selftests/bpf/cgroup_helpers.c       | 16 ++++
 tools/testing/selftests/bpf/cgroup_helpers.h       |  1 +
 .../selftests/bpf/prog_tests/cgrp_local_storage.c  | 98 +++++++++++++++++++++-
 .../selftests/bpf/progs/cgrp_ls_recursion.c        | 84 +++++++++++++++----
 .../selftests/bpf/progs/cgrp_ls_sleepable.c        | 61 ++++++++++++--
 tools/testing/selftests/bpf/progs/cgrp_ls_tp_btf.c | 82 +++++++++++++-----
 7 files changed, 298 insertions(+), 50 deletions(-)

Comments

[e-mail] Dec. 9, 2023, 1:10 a.m. UTC | #1

Hello:

This series was applied to bpf/bpf-next.git (master)
by Martin KaFai Lau <[e-mail]>:

On Wed,  6 Dec 2023 11:53:23 +0000 you wrote:
> In the current cgroup1 environment, associating operations between a cgroup
> 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.
> 
> [...]

Here is the summary with links:
  - [bpf-next,1/3] bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case
    https://git.kernel.org/bpf/bpf-next/c/73d9eb340d2b
  - [bpf-next,2/3] selftests/bpf: Add a new cgroup helper open_classid()
    https://git.kernel.org/bpf/bpf-next/c/f4199271dae1
  - [bpf-next,3/3] selftests/bpf: Add selftests for cgroup1 local storage
    https://git.kernel.org/bpf/bpf-next/c/a2c6380b17b6

You are awesome, thank you!