From patchwork Thu Jul 27 07:36:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuyi Zhou X-Patchwork-Id: 13329086 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D45CBBE72 for ; Thu, 27 Jul 2023 07:37:54 +0000 (UTC) Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76F564200 for ; Thu, 27 Jul 2023 00:37:28 -0700 (PDT) Received: by mail-oi1-x22d.google.com with SMTP id 5614622812f47-3a38953c928so601644b6e.1 for ; Thu, 27 Jul 2023 00:37:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1690443447; x=1691048247; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Uv3OYCgolDRnDe8sjWn08GTjavdgRys1P8gpfRFXymU=; b=GPxKU1wLA/ico6qT1nEEu7gHQfgASi8rquE1AHhcXYJT1YIgQWCl0gYkO+q7Q4Ajd8 ZGhT1ge1OlP7dnRkKC9NzY2sUvhgM/h6rPXqBu3xK1S9r98sHCrdmoTvcTfANYWZBoLd xfVIwZRmn2yWUEfGaYPS4U465p+g49PadC9fcYd0hx5ojquQUhWVeEKTqP+pZ9xvinLc bNKbsys0ZIGHmQCTT0vWBHPadAdI12u2RXt8ygcYMQkFpLj8uIdMWG4xFoQS93HgAPsT PwYp3/fy/qrx1r2C2MV0kCEoJMDJandD7xo85GeTJRyvBJxZslJGlHE1vTxBwPd27657 T+pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690443447; x=1691048247; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Uv3OYCgolDRnDe8sjWn08GTjavdgRys1P8gpfRFXymU=; b=ll7KkfTqLHDd5JQJbjHTChLGIVYVpQR14nA2r3SEolDnRNYQ+r0YKGorTJLZJl4ZJn GvHBA9+zTnMymG+1R+H2aXVB2WX/l9asCCIunupJNYjjV19CPnqM+rQ4tIp6OcR7spO3 eFPCgCbrHcDc4mmRDMkKuCpum/SlChR8eBWRrQQCtGMy9Bq5byCkXJZ2wqUpS/qHWDxH vLi31DGEXUXDpjeu5FAOaKYR6S36K1BF6c5/u6PfivCieVDuKn6hpjiSktPKQmOKRm94 5NRlTmABgnTO/Nn9ueyUp7m0uQUf3pcsFfRej5EjySefkFk+MEC12JS276yCdU4Ds9iy Al9A== X-Gm-Message-State: ABy/qLa3OY39a+G97tOfRVsrn3aqEV31zPwsObfGiZDnqkY5trIWMntS /IDMrXr8p576xlWSbEXXEHxQ7w== X-Google-Smtp-Source: APBJJlGHqT5qPjTtSbXoYNJy1i+7DtwD7lYrnGBfTg7InyflfRjIZJ5jUGAx6rk7oi3Ui6choddTkw== X-Received: by 2002:a05:6808:1393:b0:3a5:ca93:fb69 with SMTP id c19-20020a056808139300b003a5ca93fb69mr2618037oiw.55.1690443447035; Thu, 27 Jul 2023 00:37:27 -0700 (PDT) Received: from n37-019-243.byted.org ([180.184.51.134]) by smtp.gmail.com with ESMTPSA id s196-20020a6377cd000000b005638a70110bsm733919pgc.65.2023.07.27.00.37.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Jul 2023 00:37:26 -0700 (PDT) From: Chuyi Zhou To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, wuyun.abel@bytedance.com, robin.lu@bytedance.com, Chuyi Zhou Subject: [RFC PATCH 4/5] bpf: Add a new bpf helper to get cgroup ino Date: Thu, 27 Jul 2023 15:36:31 +0800 Message-Id: <20230727073632.44983-5-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230727073632.44983-1-zhouchuyi@bytedance.com> References: <20230727073632.44983-1-zhouchuyi@bytedance.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC This patch adds a new bpf helper bpf_get_ino_from_cgroup_id, so that we can get the inode number once we know the cgroup id. Cgroup_id is used to identify a cgroup in BPF prog. However we can't get the cgroup id directly in userspace applications. In userspace, we are used to identifying cgroups by their paths or their inodes. However, cgroup id is not always equal to the inode number, depending on the sizeof ino_t. For example, given some cgroup paths, we only care about the events related to those cgroups. We can only do this by updating these paths in a map and doing string comparison in BPF prog, which is not very convenient. However with this new helper, we just need to record the inode in a map and lookup a inode number in BPF prog. Signed-off-by: Chuyi Zhou --- include/uapi/linux/bpf.h | 7 +++++++ kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 17 +++++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 4 files changed, 32 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 9da0d61cf703..01efb289fa14 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5575,6 +5575,12 @@ union bpf_attr { * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. + * + * u64 bpf_get_ino_from_cgroup_id(u64 id) + * Description + * Get inode number from a *cgroup id*. + * Return + * Inode number. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -5789,6 +5795,7 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ + FN(get_ino_from_cgroup_id, 212, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index dc85240a0134..49dfdb2dd336 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2666,6 +2666,7 @@ const struct bpf_func_proto bpf_snprintf_btf_proto __weak; const struct bpf_func_proto bpf_seq_printf_btf_proto __weak; const struct bpf_func_proto bpf_set_retval_proto __weak; const struct bpf_func_proto bpf_get_retval_proto __weak; +const struct bpf_func_proto bpf_get_ino_from_cgroup_id_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 9e80efa59a5d..e87328b008d3 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -433,6 +433,21 @@ const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = { .ret_type = RET_INTEGER, .arg1_type = ARG_ANYTHING, }; + +BPF_CALL_1(bpf_get_ino_from_cgroup_id, u64, id) +{ + u64 ino = kernfs_id_ino(id); + + return ino; +} + +const struct bpf_func_proto bpf_get_ino_from_cgroup_id_proto = { + .func = bpf_get_ino_from_cgroup_id, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, +}; + #endif /* CONFIG_CGROUPS */ #define BPF_STRTOX_BASE_MASK 0x1F @@ -1767,6 +1782,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_get_current_cgroup_id_proto; case BPF_FUNC_get_current_ancestor_cgroup_id: return &bpf_get_current_ancestor_cgroup_id_proto; + case BPF_FUNC_get_ino_from_cgroup_id: + return &bpf_get_ino_from_cgroup_id_proto; #endif default: break; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 9da0d61cf703..661d97aacb85 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5575,6 +5575,12 @@ union bpf_attr { * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. + * + * u64 bpf_get_ino_from_cgroup_id(u64 id) + * Description + * Get inode number from a *cgroup id*. + * Return + * Inode number. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -5789,6 +5795,7 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ + FN(get_ino_from_cgroup_id, 212, ##ctx) \ /* */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't