From patchwork Thu Mar 4 05:27:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muneendra Kumar X-Patchwork-Id: 394054 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00, DATE_IN_PAST_06_12, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88F1AC433E0 for ; Thu, 4 Mar 2021 12:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F56264F1E for ; Thu, 4 Mar 2021 12:30:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240634AbhCDM3h (ORCPT ); Thu, 4 Mar 2021 07:29:37 -0500 Received: from relay.smtp-ext.broadcom.com ([192.19.221.30]:40554 "EHLO relay.smtp-ext.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240619AbhCDM3F (ORCPT ); Thu, 4 Mar 2021 07:29:05 -0500 Received: from localhost.localdomain (unknown [10.157.2.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay.smtp-ext.broadcom.com (Postfix) with ESMTPS id 353992256B; Thu, 4 Mar 2021 04:19:55 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 relay.smtp-ext.broadcom.com 353992256B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1614860395; bh=ho6NN7/oHCG8UGfKOYuFljorTKWw2Yt20bXrDOyHrzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A+Jwn6DtxpH90+SKybxl9ILuBBQ25lWA8P6RvXHepr3Jeiz7wtFXjW/rh736MxvQL j/tQbLmrpF2YcZHf5Fi4GzUc9pPltdjbJoCEEjOsOKFfzvShEnV8NuZ65GkR+kuV6E 2wVbGhzGXWmDGB8RIcM8SikhCXf42D2lNuvIHAL4= From: Muneendra To: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, tj@kernel.org, linux-nvme@lists.infradead.org, hare@suse.de Cc: jsmart2021@gmail.com, emilne@redhat.com, mkumar@redhat.com, Muneendra Subject: [PATCH v8 01/16] cgroup: Added cgroup_get_from_id Date: Thu, 4 Mar 2021 10:57:11 +0530 Message-Id: <1614835646-16217-2-git-send-email-muneendra.kumar@broadcom.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1614835646-16217-1-git-send-email-muneendra.kumar@broadcom.com> References: <1614835646-16217-1-git-send-email-muneendra.kumar@broadcom.com> Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Added a new function cgroup_get_from_id to retrieve the cgroup associated with cgroup id. Exported the same as this can be used by blk-cgorup.c Added function declaration of cgroup_get_from_id in cgorup.h This patch also exported the function cgroup_get_e_css as this is getting used in blk-cgroup.h Signed-off-by: Muneendra Reviewed-by: Hannes Reinecke --- v8: No change v7: No change v6: No change v5: renamed the function cgroup_get_from_kernfs_id to cgroup_get_from_id v4: No change v3: Exported the cgroup_get_e_css v2: New patch --- include/linux/cgroup.h | 6 ++++++ kernel/cgroup/cgroup.c | 26 ++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 451c2d26a5db..9573d45de065 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -696,6 +696,7 @@ static inline void cgroup_kthread_ready(void) } void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); +struct cgroup *cgroup_get_from_id(u64 id); #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -743,6 +744,11 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task, static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) {} + +static struct cgroup *cgroup_get_from_id(u64 id) +{ + return NULL; +} #endif /* !CONFIG_CGROUPS */ #ifdef CONFIG_CGROUPS diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 613845769103..e5e37b2f6a10 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -577,6 +577,7 @@ struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp, rcu_read_unlock(); return css; } +EXPORT_SYMBOL_GPL(cgroup_get_e_css); static void cgroup_get_live(struct cgroup *cgrp) { @@ -5793,6 +5794,31 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) kernfs_put(kn); } +/* + * cgroup_get_from_id : get the cgroup associated with cgroup id + * @id: cgroup id + * On success it returns the cgrp on failure it returns NULL + */ +struct cgroup *cgroup_get_from_id(u64 id) +{ + struct kernfs_node *kn; + struct cgroup *cgrp = NULL; + + mutex_lock(&cgroup_mutex); + kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id); + if (!kn) + goto out_unlock; + + cgrp = kn->priv; + if (cgroup_is_dead(cgrp) || !cgroup_tryget(cgrp)) + cgrp = NULL; + kernfs_put(kn); +out_unlock: + mutex_unlock(&cgroup_mutex); + return cgrp; +} +EXPORT_SYMBOL_GPL(cgroup_get_from_id); + /* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy