From patchwork Fri Oct 23 12:32:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Baluta X-Patchwork-Id: 7472791 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 5BEEF9F6E4 for ; Fri, 23 Oct 2015 12:33:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5E1F1209AF for ; Fri, 23 Oct 2015 12:33:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BC69209AD for ; Fri, 23 Oct 2015 12:33:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752780AbbJWMab (ORCPT ); Fri, 23 Oct 2015 08:30:31 -0400 Received: from mga03.intel.com ([134.134.136.65]:39863 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752762AbbJWMa1 (ORCPT ); Fri, 23 Oct 2015 08:30:27 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP; 23 Oct 2015 05:30:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,186,1444719600"; d="scan'208";a="801096024" Received: from dbaluta.rb.intel.com ([10.237.104.107]) by orsmga001.jf.intel.com with ESMTP; 23 Oct 2015 05:30:22 -0700 From: Daniel Baluta To: jic23@kernel.org, jlbec@evilplan.org, linux-iio@vger.kernel.org, linux-fsdevel@vger.kernel.org, lars@metafoo.de, hch@lst.de Cc: knaack.h@gmx.de, linux-kernel@vger.kernel.org, octavian.purdila@intel.com, pebolle@tiscali.nl, patrick.porlan@intel.com, adriana.reus@intel.com, constantin.musca@intel.com, marten@intuitiveaerial.com, daniel.baluta@intel.com, cristina.opriceana@gmail.com, pmeerw@pmeerw.net, viro@zeniv.linux.org.uk, akpm@linux-foundation.org Subject: [PATCH v9 1/5] configfs: Allow dynamic group creation Date: Fri, 23 Oct 2015 15:32:34 +0300 Message-Id: <1445603558-27693-2-git-send-email-daniel.baluta@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445603558-27693-1-git-send-email-daniel.baluta@intel.com> References: <1445603558-27693-1-git-send-email-daniel.baluta@intel.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We don't want to hardcode default groups at subsystem creation time. We export: * configfs_register_group * configfs_unregister_group to allow drivers to programatically create/destroy groups later, after module init time. This is needed for IIO configfs support. Suggested-by: Lars-Peter Clausen Signed-off-by: Daniel Baluta Reviewed-by: Christoph Hellwig --- fs/configfs/dir.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/configfs.h | 8 ++++ 2 files changed, 110 insertions(+) diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index c81ce7f..bf76795 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1636,6 +1636,108 @@ const struct file_operations configfs_dir_operations = { .iterate = configfs_readdir, }; +/** + * configfs_alloc_group() - allocate a configfs group + * @name: group name + * @item_type: config_item associated with the allocated group + * + * Dynamically allocates and initialize a group specified by name and + * config_item_type. We need kzalloc'ed memory because default_group + * is empty. + * + * Return: allocated config group or ERR_PTR() on error + */ +struct config_group * +configfs_alloc_group(const char *name, struct config_item_type *item_type) +{ + struct config_group *group; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return ERR_PTR(-ENOMEM); + config_group_init_type_name(group, name, item_type); + + return group; +} +EXPORT_SYMBOL(configfs_alloc_group); + +/** + * configfs_free_group() - frees memory for a configfs group + * @group: group to be 'eliberated' + */ +void configfs_free_group(struct config_group *group) +{ + kfree(group); +} +EXPORT_SYMBOL(configfs_free_group); + +/** + * configfs_register_group - creates a parent-child relation between two groups + * @parent_group: parent group + * @group: child group + * + * link groups, creates dentry for the child and attaches it to the + * parent dentry. + * + * Return: 0 on success, negative errno code on error + */ +int configfs_register_group(struct config_group *parent_group, + struct config_group *group) +{ + struct configfs_subsystem *subsys = parent_group->cg_subsys; + struct dentry *parent; + int ret; + + mutex_lock(&subsys->su_mutex); + link_group(parent_group, group); + mutex_unlock(&subsys->su_mutex); + + parent = parent_group->cg_item.ci_dentry; + + mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT); + ret = create_default_group(parent_group, group); + if (!ret) { + spin_lock(&configfs_dirent_lock); + configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata); + spin_unlock(&configfs_dirent_lock); + } + mutex_unlock(&d_inode(parent)->i_mutex); + return ret; +} +EXPORT_SYMBOL(configfs_register_group); + +/** + * configfs_unregister_group() - unregisters a child group from its parent + * + * @group: parent group to be unregistered + * + * Undoes condigfs_register_group() + */ +void configfs_unregister_group(struct config_group *group) +{ + struct configfs_subsystem *subsys = group->cg_subsys; + struct dentry *dentry = group->cg_item.ci_dentry; + struct dentry *parent = group->cg_item.ci_parent->ci_dentry; + + mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT); + spin_lock(&configfs_dirent_lock); + configfs_detach_prep(dentry, NULL); + spin_unlock(&configfs_dirent_lock); + + configfs_detach_group(&group->cg_item); + d_inode(dentry)->i_flags |= S_DEAD; + dont_mount(dentry); + d_delete(dentry); + mutex_unlock(&d_inode(parent)->i_mutex); + + dput(dentry); + + mutex_lock(&subsys->su_mutex); + unlink_group(group); + mutex_unlock(&subsys->su_mutex); +} +EXPORT_SYMBOL(configfs_unregister_group); + int configfs_register_subsystem(struct configfs_subsystem *subsys) { int err; diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 63a36e8..c522a5e 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -252,6 +252,14 @@ static inline struct configfs_subsystem *to_configfs_subsystem(struct config_gro int configfs_register_subsystem(struct configfs_subsystem *subsys); void configfs_unregister_subsystem(struct configfs_subsystem *subsys); +struct config_group * +configfs_alloc_group(const char *name, struct config_item_type *item_type); +void configfs_free_group(struct config_group *group); + +int configfs_register_group(struct config_group *parent_group, + struct config_group *group); +void configfs_unregister_group(struct config_group *group); + /* These functions can sleep and can alloc with GFP_KERNEL */ /* WARNING: These cannot be called underneath configfs callbacks!! */ int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target);