From nobody Tue Apr 7 05:10:04 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9F9FC433F5 for ; Tue, 11 Oct 2022 00:34:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229552AbiJKAeN (ORCPT ); Mon, 10 Oct 2022 20:34:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbiJKAeH (ORCPT ); Mon, 10 Oct 2022 20:34:07 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC944748C0 for ; Mon, 10 Oct 2022 17:34:05 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id j25-20020aa78d19000000b00561f966ae13so6374654pfe.14 for ; Mon, 10 Oct 2022 17:34:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=nt0hZpqjZYJlwAVjzUzDxwYteGmfv83PaANdrORvyzY=; b=ay7HauFPH8wegVHkBuk9+qrh+plSbcKcv5NaQwdc+wDJkt5E2xl7LGxvAe30oD7Tlm xfCsLbQUQSeZIATvCfTgpW1P+iAjX0UL8XYQ46/zB4U56Nk1gQh7Cl/RkSKLOi2aD/fJ WdwqcT+mythyJ/AN5hL6XCeJE8aylwW1z+fxMP9iNQU7LmOp9nPyITikDEc+QcNYPFe8 CVVHriM88Vw34IT2rQvmF3uISMnQcPpkDTFSXsNr1kIIdrmqs7ulupf1ApUJbPYkj3Cp DfPpaK4zFvyq5PWTnUKpSL+bQNTxZmpnjH2T5Cz/+3E/44XnZJxI2wtC7O/Z/QyyknpT 8mcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=nt0hZpqjZYJlwAVjzUzDxwYteGmfv83PaANdrORvyzY=; b=semJx8X6xghB5YlWMRA0DD6Q0Jd0z9fx7vpUPsnBIhOH4RtH9KV1hP5ZuOgqgjo3ed G8qaYE79Ng5ARgNb4HSlzaXV3iaYTBq3t+TgjuS0xu4np3LPNumlYQjVWKpt9xiMaEmj ZS+rufiKwsi4+ZnNo922U/hdHpO4kzDXZw2hprfhTrUh/usQFzZa6vU3pjFoewgMixdv q+dNbRIBK9Lbz+hW2twc7okGTfjdHFc19FMyMCaQL9Za3P6WQ8dh0bxIDr/kOEdGAqzo 8Vnyc243JNi5kTJGQH6uBUc0vtSk1MmXeUMNjRp0Aned2xJq1TNF9ARmENHYNFqMDXTk kDXA== X-Gm-Message-State: ACrzQf2k7vNiZm/4DR8PvFjxASJmthyKfhprdDqGC+Wq+aGbNhw4qOc2 gCsCvtZsbT96vjXMoyIGqpaQqQ5nIasV8qIU X-Google-Smtp-Source: AMsMyM4Xu9gEvJAvFY+PEekqSUs7CxT5zdRa2B62bPjfBvI7OYtf4yJrksqef16M5Kr74IlieAi2TFf+Ih7IZcSo X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a05:6a00:24cb:b0:563:5499:b73 with SMTP id d11-20020a056a0024cb00b0056354990b73mr8992534pfv.44.1665448445285; Mon, 10 Oct 2022 17:34:05 -0700 (PDT) Date: Tue, 11 Oct 2022 00:33:58 +0000 In-Reply-To: <20221011003359.3475263-1-yosryahmed@google.com> Mime-Version: 1.0 References: <20221011003359.3475263-1-yosryahmed@google.com> X-Mailer: git-send-email 2.38.0.rc1.362.ged0d419d3c-goog Message-ID: <20221011003359.3475263-2-yosryahmed@google.com> Subject: [PATCH v2 1/2] cgroup: add cgroup_v1v2_get_from_[fd/file]() From: Yosry Ahmed To: Tejun Heo , Zefan Li , Johannes Weiner , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Yosry Ahmed Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add cgroup_v1v2_get_from_fd() and cgroup_v1v2_get_from_file() that support both cgroup1 and cgroup2. Signed-off-by: Yosry Ahmed --- include/linux/cgroup.h | 1 + kernel/cgroup/cgroup.c | 50 +++++++++++++++++++++++++++++++++++++----- 2 files changed, 45 insertions(+), 6 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 398f0bce7c21..a88de5bdeaa9 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -106,6 +106,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(= struct dentry *dentry, =20 struct cgroup *cgroup_get_from_path(const char *path); struct cgroup *cgroup_get_from_fd(int fd); +struct cgroup *cgroup_v1v2_get_from_fd(int fd); =20 int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 72e97422e9d9..be167e15ef1a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -6208,16 +6208,36 @@ void cgroup_fork(struct task_struct *child) INIT_LIST_HEAD(&child->cg_list); } =20 -static struct cgroup *cgroup_get_from_file(struct file *f) +/** + * cgroup_v1v2_get_from_file - get a cgroup pointer from a file pointer + * @f: file corresponding to cgroup_dir + * + * Find the cgroup from a file pointer associated with a cgroup directory. + * Returns a pointer to the cgroup on success. ERR_PTR is returned if the + * cgroup cannot be found. + */ +static struct cgroup *cgroup_v1v2_get_from_file(struct file *f) { struct cgroup_subsys_state *css; - struct cgroup *cgrp; =20 css =3D css_tryget_online_from_dir(f->f_path.dentry, NULL); if (IS_ERR(css)) return ERR_CAST(css); =20 - cgrp =3D css->cgroup; + return css->cgroup; +} + +/** + * cgroup_get_from_file - same as cgroup_v1v2_get_from_file, but only supp= orts + * cgroup2. + */ +static struct cgroup *cgroup_get_from_file(struct file *f) +{ + struct cgroup *cgrp =3D cgroup_v1v2_get_from_file(f); + + if (IS_ERR(cgrp)) + return ERR_CAST(cgrp); + if (!cgroup_on_dfl(cgrp)) { cgroup_put(cgrp); return ERR_PTR(-EBADF); @@ -6720,14 +6740,14 @@ EXPORT_SYMBOL_GPL(cgroup_get_from_path); =20 /** * cgroup_get_from_fd - get a cgroup pointer from a fd - * @fd: fd obtained by open(cgroup2_dir) + * @fd: fd obtained by open(cgroup_dir) * * Find the cgroup from a fd which should be obtained * by opening a cgroup directory. Returns a pointer to the * cgroup on success. ERR_PTR is returned if the cgroup * cannot be found. */ -struct cgroup *cgroup_get_from_fd(int fd) +struct cgroup *cgroup_v1v2_get_from_fd(int fd) { struct cgroup *cgrp; struct file *f; @@ -6736,10 +6756,28 @@ struct cgroup *cgroup_get_from_fd(int fd) if (!f) return ERR_PTR(-EBADF); =20 - cgrp =3D cgroup_get_from_file(f); + cgrp =3D cgroup_v1v2_get_from_file(f); fput(f); return cgrp; } + +/** + * cgroup_get_from_fd - same as cgroup_v1v2_get_from_fd, but only supports + * cgroup2. + */ +struct cgroup *cgroup_get_from_fd(int fd) +{ + struct cgroup *cgrp =3D cgroup_v1v2_get_from_fd(fd); + + if (IS_ERR(cgrp)) + return ERR_CAST(cgrp); + + if (!cgroup_on_dfl(cgrp)) { + cgroup_put(cgrp); + return ERR_PTR(-EBADF); + } + return cgrp; +} EXPORT_SYMBOL_GPL(cgroup_get_from_fd); =20 static u64 power_of_ten(int power) --=20 2.38.0.rc1.362.ged0d419d3c-goog