From patchwork Wed Jul 12 18:49:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaohua Li X-Patchwork-Id: 9837257 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2B9A0602D8 for ; Wed, 12 Jul 2017 18:51:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EB4827FA6 for ; Wed, 12 Jul 2017 18:51:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12A6628676; Wed, 12 Jul 2017 18:51:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B47B827FA6 for ; Wed, 12 Jul 2017 18:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753798AbdGLSuw (ORCPT ); Wed, 12 Jul 2017 14:50:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:55714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753786AbdGLSuv (ORCPT ); Wed, 12 Jul 2017 14:50:51 -0400 Received: from shli-virt.localdomain (unknown [199.201.64.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B835B22C9C; Wed, 12 Jul 2017 18:50:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B835B22C9C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=shli@fb.com From: Shaohua Li To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: tj@kernel.org, gregkh@linuxfoundation.org, hch@lst.de, axboe@fb.com, rostedt@goodmis.org, lizefan@huawei.com, Kernel-team@fb.com, Shaohua Li Subject: [PATCH V5 07/11] cgroup: export fhandle info for a cgroup Date: Wed, 12 Jul 2017 11:49:52 -0700 Message-Id: <4c59c56556b3c4051cb63b8ca2be920be177c0b3.1499884836.git.shli@fb.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Shaohua Li Add an API to export cgroup fhandle info. We don't export a full 'struct file_handle', there are unrequired info. Sepcifically, cgroup is always a directory, so we don't need a 'FILEID_INO32_GEN_PARENT' type fhandle, we only need export the inode number and generation number just like what generic_fh_to_dentry does. And we can avoid the overhead of getting an inode too, since kernfs_node_id (ino and generation) has all the info required. Acked-by: Tejun Heo Signed-off-by: Shaohua Li --- include/linux/cgroup.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 30c6877..52ef9a6 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -609,6 +609,10 @@ static inline void cgroup_kthread_ready(void) current->no_cgroup_migration = 0; } +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return &cgrp->kn->id; +} #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -631,6 +635,10 @@ static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } static inline void cgroup_init_kthreadd(void) {} static inline void cgroup_kthread_ready(void) {} +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return NULL; +} static inline bool task_under_cgroup_hierarchy(struct task_struct *task, struct cgroup *ancestor)