From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbbKJGvc (ORCPT ); Tue, 10 Nov 2015 01:51:32 -0500 Received: from verein.lst.de ([213.95.11.211]:55672 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbbKJGva (ORCPT ); Tue, 10 Nov 2015 01:51:30 -0500 Date: Tue, 10 Nov 2015 07:51:26 +0100 From: Christoph Hellwig To: akpm@linux-foundation.org Cc: Daniel Baluta , jic23@kernel.org, jlbec@evilplan.org, linux-iio@vger.kernel.org, linux-fsdevel@vger.kernel.org, lars@metafoo.de, hch@lst.de, 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, cristina.opriceana@gmail.com, pmeerw@pmeerw.net, viro@zeniv.linux.org.uk, akpm@linux-foundation.org Subject: Re: [PATCH v10 1/5] configfs: Allow dynamic group creation Message-ID: <20151110065126.GA20339@lst.de> References: <1445614411-533-1-git-send-email-daniel.baluta@intel.com> <1445614411-533-2-git-send-email-daniel.baluta@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445614411-533-2-git-send-email-daniel.baluta@intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew, is this simple addition something you could still send on to Linus for this merge window? I would make my life easier to have it in so I could start using it in patches for various trees in the next merge window. Thanks, Christoph On Fri, Oct 23, 2015 at 06:33:27PM +0300, Daniel Baluta wrote: > 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 > --- > fs/configfs/dir.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/configfs.h | 10 +++++ > 2 files changed, 120 insertions(+) > > diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c > index c81ce7f..a7a1b21 100644 > --- a/fs/configfs/dir.c > +++ b/fs/configfs/dir.c > @@ -1636,6 +1636,116 @@ const struct file_operations configfs_dir_operations = { > .iterate = configfs_readdir, > }; > > +/** > + * 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 configfs_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); > + > +/** > + * configfs_register_default_group() - allocates and registers a child group > + * @parent_group: parent group > + * @name: child group name > + * @item_type: child item type description > + * > + * boilerplate to allocate and register a child group with its parent. We need > + * kzalloc'ed memory because child's default_group is initially empty. > + * > + * Return: allocated config group or ERR_PTR() on error > + */ > +struct config_group * > +configfs_register_default_group(struct config_group *parent_group, > + const char *name, > + struct config_item_type *item_type) > +{ > + int ret; > + 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); > + > + ret = configfs_register_group(parent_group, group); > + if (ret) { > + kfree(group); > + return ERR_PTR(ret); > + } > + return group; > +} > +EXPORT_SYMBOL(configfs_register_default_group); > + > +/** > + * configfs_unregister_default_group() - unregisters and frees a child group > + * @group: the group to act on > + */ > +void configfs_unregister_default_group(struct config_group *group) > +{ > + configfs_unregister_group(group); > + kfree(group); > +} > +EXPORT_SYMBOL(configfs_unregister_default_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..931ca25 100644 > --- a/include/linux/configfs.h > +++ b/include/linux/configfs.h > @@ -252,6 +252,16 @@ 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); > > +int configfs_register_group(struct config_group *parent_group, > + struct config_group *group); > +void configfs_unregister_group(struct config_group *group); > + > +struct config_group * > +configfs_register_default_group(struct config_group *parent_group, > + const char *name, > + struct config_item_type *item_type); > +void configfs_unregister_default_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); > -- > 1.9.1 ---end quoted text---