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Message-ID: <2ba0ee79-2e7e-6807-3312-1a2c5ef3bae0@linux.dev>
Date:   Tue, 11 Oct 2022 09:46:27 -0700
MIME-Version: 1.0
Subject: Re: [PATCH v2 2/2] bpf: cgroup_iter: support cgroup1 using cgroup fd
Content-Language: en-US
To:     Yosry Ahmed <yosryahmed@google.com>, Tejun Heo <tj@kernel.org>
Cc:     cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Yonghong Song <yhs@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Song Liu <song@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>
References: <20221011003359.3475263-1-yosryahmed@google.com>
 <20221011003359.3475263-3-yosryahmed@google.com>
From:   Martin KaFai Lau <martin.lau@linux.dev>
In-Reply-To: <20221011003359.3475263-3-yosryahmed@google.com>
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On 10/10/22 5:33 PM, Yosry Ahmed wrote:
> Use cgroup_v1v2_get_from_fd() in cgroup_iter to support attaching to
> both cgroup v1 and v2 using fds.
> 
> Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> ---
>   kernel/bpf/cgroup_iter.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
> index 0d200a993489..9fcf09f2ef00 100644
> --- a/kernel/bpf/cgroup_iter.c
> +++ b/kernel/bpf/cgroup_iter.c
> @@ -196,7 +196,7 @@ static int bpf_iter_attach_cgroup(struct bpf_prog *prog,
>   		return -EINVAL;
>   
>   	if (fd)
> -		cgrp = cgroup_get_from_fd(fd);
> +		cgrp = cgroup_v1v2_get_from_fd(fd);

Acked-by: Martin KaFai Lau <martin.lau@kernel.org>

Tejun, patch 1 should depend on a recent revert that is not in the bpf tree yet. 
  Do you want to take this set to the cgroup tree?

>   	else if (id)
>   		cgrp = cgroup_get_from_id(id);
>   	else /* walk the entire hierarchy by default. */