From patchwork Tue Oct 17 12:45:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13425097 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 46C34405E3 for ; Tue, 17 Oct 2023 12:46:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Yl/lG7wc" Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94A0583; Tue, 17 Oct 2023 05:46:10 -0700 (PDT) Received: by mail-ot1-x336.google.com with SMTP id 46e09a7af769-6c4b9e09528so3821012a34.3; Tue, 17 Oct 2023 05:46:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697546770; x=1698151570; darn=vger.kernel.org; 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=RGlzNf6WdsmkGHoptnlJhKt/0P2xY3kxLxvh9NU6HqI=; b=Yl/lG7wcQKqkenRNoy09FzI71o2a4StV0UIMHsf33iFCYoWarFqf+OPpKwXZq74dE1 MilIzmZxJ9f08+5PHlsJdx/t4V5gUo9r9CZfM0Xrm9tGgrW7RwGuzSkkd3enxfGuWePs qo2jaNyUtlBWk9GuIvFa8tnTNrX7Pghcd/hUmVsZblAFtxC0m0dV4BSEjLdsEJbTBMzs pngb48uUXLw7A+Py+LfmxI7ZDVGtoGY3Odo1EkcXyeHvZnLoHxVLHKqok6k0DTvXmbyV mvLGzMqSWiJLL8gbJLkJDB+n7K8A65f3xcHu0+1hbBHSmkbn6cSwjNnu4+tj+GsvooUK fNrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697546770; x=1698151570; 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=RGlzNf6WdsmkGHoptnlJhKt/0P2xY3kxLxvh9NU6HqI=; b=aJFd7YmR220oLotoziR1TXpnr2ydT//IjwsAUcRtkOUymjUVBLlYxn0fuAYyWK1M/p fFCFegCKJ6x1grAsttoA27fvOSLyN8TVPt4Xvlbmk3tkbc6397LKlhkX+Y89mIL6BAr8 B+LgF2lW+tlWSTqcMMmVZwVc0Iatf4oYf0zv1aOxbbIDfZtOzf2EC5BYc4Sg7Ad3YYBj FELVIl2a43LCP86boxQDCJJMTe3ep/kZZSdM57eGox4StSvqQ59MvKhjVfB5xAPflHU0 nrT6uyH1UPrPW+Rg13R3BuziGFKS98IpNEbDOsyhQ+Go+dZgmUYEylGvw9uUNzvbaZjh BErQ== X-Gm-Message-State: AOJu0Yw2lTsg8C/Tq3ClhytH5rnRDbM0HAPa2i/XnS4DPnbzSyX1vcvY Ok9Mu/E918+DPMtaJJBW6X4= X-Google-Smtp-Source: AGHT+IHJcsuTDiUuaPpXZLWALWPW2owS5P6jdDAXIg+MkS/VjV+JAvCzmQUi9KL0wnpm0RbWS1szhw== X-Received: by 2002:a05:6830:56:b0:6b8:6785:ed0b with SMTP id d22-20020a056830005600b006b86785ed0bmr2266465otp.30.1697546769877; Tue, 17 Oct 2023 05:46:09 -0700 (PDT) Received: from vultr.guest ([2001:19f0:ac01:3b2:5400:4ff:fe9b:d21b]) by smtp.gmail.com with ESMTPSA id fa36-20020a056a002d2400b006bdf4dfbe0dsm1375595pfb.12.2023.10.17.05.46.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Oct 2023 05:46:09 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, tj@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, yosryahmed@google.com, mkoutny@suse.com, sinquersw@gmail.com Cc: cgroups@vger.kernel.org, bpf@vger.kernel.org, Yafang Shao Subject: [RFC PATCH bpf-next v2 3/9] cgroup: Add a new helper for cgroup1 hierarchy Date: Tue, 17 Oct 2023 12:45:40 +0000 Message-Id: <20231017124546.24608-4-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231017124546.24608-1-laoar.shao@gmail.com> References: <20231017124546.24608-1-laoar.shao@gmail.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,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS 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 A new helper is added for cgroup1 hierarchy: - task_get_cgroup1_within_hierarchy Acquires the associated cgroup of a task within a specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID. This helper function is added to facilitate the tracing of tasks within a particular container or cgroup dir in BPF programs. It's important to note that this helper is designed specifically for cgroup1 only. Signed-off-by: Yafang Shao --- include/linux/cgroup.h | 6 +++++- kernel/cgroup/cgroup-internal.h | 1 - kernel/cgroup/cgroup-v1.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 2 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b307013b9c6c..0cd3983822c3 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -71,6 +71,7 @@ struct css_task_iter { extern struct file_system_type cgroup_fs_type; extern struct cgroup_root cgrp_dfl_root; extern struct css_set init_css_set; +extern spinlock_t css_set_lock; #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys; #include @@ -159,6 +160,8 @@ void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, struct css_task_iter *it); struct task_struct *css_task_iter_next(struct css_task_iter *it); void css_task_iter_end(struct css_task_iter *it); +struct cgroup *task_cgroup_from_root(struct task_struct *task, + struct cgroup_root *root); /** * css_for_each_child - iterate through children of a css @@ -388,7 +391,6 @@ static inline void cgroup_unlock(void) * as locks used during the cgroup_subsys::attach() methods. */ #ifdef CONFIG_PROVE_RCU -extern spinlock_t css_set_lock; #define task_css_set_check(task, __c) \ rcu_dereference_check((task)->cgroups, \ rcu_read_lock_sched_held() || \ @@ -855,4 +857,6 @@ static inline void cgroup_bpf_put(struct cgroup *cgrp) {} #endif /* CONFIG_CGROUP_BPF */ +struct cgroup *task_get_cgroup1_within_hierarchy(struct task_struct *tsk, int hierarchy_id); + #endif /* _LINUX_CGROUP_H */ diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 321af20ea15f..3a7b0cc911f7 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -164,7 +164,6 @@ struct cgroup_mgctx { #define DEFINE_CGROUP_MGCTX(name) \ struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name) -extern spinlock_t css_set_lock; extern struct cgroup_subsys *cgroup_subsys[]; extern struct list_head cgroup_roots; diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index c487ffef6652..571071d45e4d 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -1263,6 +1263,39 @@ int cgroup1_get_tree(struct fs_context *fc) return ret; } +/** + * task_cgroup_id_within_hierarchy - Acquires the associated cgroup of a task + * within a specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by + * its hierarchy ID. + * @tsk: The target task + * @hierarchy_id: The ID of a cgroup1 hierarchy + * + * On success, the cgroup is returned. On failure, ERR_PTR is returned. + * We limit it to cgroup1 only. + */ +struct cgroup *task_get_cgroup1_within_hierarchy(struct task_struct *tsk, int hierarchy_id) +{ + struct cgroup *cgrp = ERR_PTR(-ENOENT); + struct cgroup_root *root; + + rcu_read_lock(); + list_for_each_entry(root, &cgroup_roots, root_list) { + /* cgroup1 only*/ + if (root == &cgrp_dfl_root) + continue; + if (root->hierarchy_id != hierarchy_id) + continue; + spin_lock_irq(&css_set_lock); + cgrp = task_cgroup_from_root(tsk, root); + if (!cgrp || !cgroup_tryget(cgrp)) + cgrp = ERR_PTR(-ENOENT); + spin_unlock_irq(&css_set_lock); + break; + } + rcu_read_unlock(); + return cgrp; +} + static int __init cgroup1_wq_init(void) { /*