Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752463AbdF1QcY (ORCPT ); Wed, 28 Jun 2017 12:32:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:39174 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751927AbdF1QaJ (ORCPT ); Wed, 28 Jun 2017 12:30:09 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C524B22BD5 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 V4 07/12] cgroup: export fhandle info for a cgroup Date: Wed, 28 Jun 2017 09:29:57 -0700 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 43 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. 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) -- 2.9.3