Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933003AbbGSTZt (ORCPT ); Sun, 19 Jul 2015 15:25:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38667 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932628AbbGSTLk (ORCPT ); Sun, 19 Jul 2015 15:11:40 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Eric W. Biederman" Subject: [PATCH 4.0 05/58] sysfs: Add support for permanently empty directories to serve as mount points. Date: Sun, 19 Jul 2015 12:10:43 -0700 Message-Id: <20150719190811.485407294@linuxfoundation.org> X-Mailer: git-send-email 2.4.6 In-Reply-To: <20150719190811.308546345@linuxfoundation.org> References: <20150719190811.308546345@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3198 Lines: 101 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit 87d2846fcf88113fae2341da1ca9a71f0d916f2c upstream. Add two functions sysfs_create_mount_point and sysfs_remove_mount_point that hang a permanently empty directory off of a kobject or remove a permanently emptpy directory hanging from a kobject. Export these new functions so modular filesystems can use them. Acked-by: Greg Kroah-Hartman Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 15 +++++++++++++++ 2 files changed, 49 insertions(+) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -121,3 +121,37 @@ int sysfs_move_dir_ns(struct kobject *ko return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); } + +/** + * sysfs_create_mount_point - create an always empty directory + * @parent_kobj: kobject that will contain this always empty directory + * @name: The name of the always empty directory to add + */ +int sysfs_create_mount_point(struct kobject *parent_kobj, const char *name) +{ + struct kernfs_node *kn, *parent = parent_kobj->sd; + + kn = kernfs_create_empty_dir(parent, name); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, name); + return PTR_ERR(kn); + } + + return 0; +} +EXPORT_SYMBOL_GPL(sysfs_create_mount_point); + +/** + * sysfs_remove_mount_point - remove an always empty directory. + * @parent_kobj: kobject that will contain this always empty directory + * @name: The name of the always empty directory to remove + * + */ +void sysfs_remove_mount_point(struct kobject *parent_kobj, const char *name) +{ + struct kernfs_node *parent = parent_kobj->sd; + + kernfs_remove_by_name_ns(parent, name, NULL); +} +EXPORT_SYMBOL_GPL(sysfs_remove_mount_point); --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -195,6 +195,10 @@ int __must_check sysfs_rename_dir_ns(str int __must_check sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, const void *new_ns); +int __must_check sysfs_create_mount_point(struct kobject *parent_kobj, + const char *name); +void sysfs_remove_mount_point(struct kobject *parent_kobj, + const char *name); int __must_check sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, @@ -283,6 +287,17 @@ static inline int sysfs_move_dir_ns(stru return 0; } +static inline int sysfs_create_mount_point(struct kobject *parent_kobj, + const char *name) +{ + return 0; +} + +static inline void sysfs_remove_mount_point(struct kobject *parent_kobj, + const char *name) +{ +} + static inline int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, const void *ns) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/