From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 4/7] sysfs: Implement sysfs_rename_link Date: Mon, 11 Jan 2010 12:21:52 -0800 Message-ID: <1263241315-19499-4-git-send-email-ebiederm@xmission.com> References: Cc: Kay Sievers , linux-kernel@vger.kernel.org, Tejun Heo , Cornelia Huck , linux-fsdevel@vger.kernel.org, Eric Dumazet , Benjamin LaHaise , Serge Hallyn , "Eric W. Biederman" , Benjamin Thery , Daniel Lezcano , "Eric W. Biederman" To: Greg Kroah-Hartman Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:40034 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754386Ab0AKUWP (ORCPT ); Mon, 11 Jan 2010 15:22:15 -0500 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Eric W. Biederman Because of rename ordering problems we occassionally give false warnings about invalid sysfs operations. So using sysfs_rename create a sysfs_rename_link function that doesn't need strange workarounds. Cc: Benjamin Thery Cc: Daniel Lezcano Cc: Tejun Heo Signed-off-by: Eric W. Biederman --- fs/sysfs/symlink.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 9 +++++++++ 2 files changed, 47 insertions(+), 0 deletions(-) diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index c5eff49..1b9a3a1 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -123,6 +123,44 @@ void sysfs_remove_link(struct kobject * kobj, const char * name) sysfs_hash_and_remove(parent_sd, name); } +/** + * sysfs_rename_link - rename symlink in object's directory. + * @kobj: object we're acting for. + * @targ: object we're pointing to. + * @old: previous name of the symlink. + * @new: new name of the symlink. + * + * A helper function for the common rename symlink idiom. + */ +int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, + const char *old, const char *new) +{ + struct sysfs_dirent *parent_sd, *sd = NULL; + int result; + + if (!kobj) + parent_sd = &sysfs_root; + else + parent_sd = kobj->sd; + + result = -ENOENT; + sd = sysfs_get_dirent(parent_sd, old); + if (!sd) + goto out; + + result = -EINVAL; + if (sysfs_type(sd) != SYSFS_KOBJ_LINK) + goto out; + if (sd->s_symlink.target_sd->s_dir.kobj != targ) + goto out; + + result = sysfs_rename(sd, parent_sd, new); + +out: + sysfs_put(sd); + return result; +} + static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, struct sysfs_dirent *target_sd, char *path) { diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index cfa8308..e322573 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -110,6 +110,9 @@ int __must_check sysfs_create_link_nowarn(struct kobject *kobj, const char *name); void sysfs_remove_link(struct kobject *kobj, const char *name); +int sysfs_rename_link(struct kobject *kobj, struct kobject *target, + const char *old_name, const char *new_name); + int __must_check sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp); int sysfs_update_group(struct kobject *kobj, @@ -203,6 +206,12 @@ static inline void sysfs_remove_link(struct kobject *kobj, const char *name) { } +static inline int sysfs_rename_link(struct kobject *k, struct kobject *t, + const char *old_name, const char *new_name) +{ + return 0; +} + static inline int sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) { -- 1.6.5.2.143.g8cc62