From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 22/20] sysfs: Make sysfs_rename_link atomic Date: Sat, 23 May 2009 13:13:08 -0700 Message-ID: <1243109591-21611-2-git-send-email-ebiederm@xmission.com> References: Cc: , Tejun Heo , Cornelia Huck , , "Eric W. Biederman" , "Eric W. Biederman" To: Andrew Morton , Greg Kroah-Hartman Return-path: Received: from out01.mta.xmission.com ([166.70.13.231]:55171 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754065AbZEWUNq (ORCPT ); Sat, 23 May 2009 16:13:46 -0400 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Eric W. Biederman Use the existing sysfs_rename to make sysfs_rename_link an atomic operation that does less work. While I am at add additional sanity checking to ensure it is a symlink I am renaming. Signed-off-by: Eric W. Biederman --- fs/sysfs/symlink.c | 26 ++++++++++++++++++++++++-- 1 files changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index fc5fc86..39d050b 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -106,8 +106,30 @@ void sysfs_remove_link(struct kobject * kobj, const char * name) int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, const char *old, const char *new) { - sysfs_remove_link(kobj, old); - return sysfs_create_link(kobj, targ, 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, -- 1.6.3.1.54.g99dd.dirty