From ebiederm@xmission.com Mon Nov 30 09:15:51 2009 From: "Eric W. Biederman" Date: Fri, 20 Nov 2009 16:08:54 -0800 Subject: sysfs: In sysfs_chmod_file lazily propagate the mode change. To: Greg KH Cc: Greg Kroah-Hartman , "Eric W. Biederman" , "Eric W. Biederman" Message-ID: <1258762140-27810-5-git-send-email-ebiederm@xmission.com> From: Eric W. Biederman Now that sysfs_getattr and sysfs_permission refresh the vfs inode there is no need to immediatly push the mode change into the vfs cache. Reducing the amount of work needed and simplifying the locking. Acked-by: Tejun Heo Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 31 ++++++++----------------------- 1 file changed, 8 insertions(+), 23 deletions(-) --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -579,38 +579,23 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_grou */ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) { - struct sysfs_dirent *victim_sd = NULL; - struct dentry *victim = NULL; - struct inode * inode; + struct sysfs_dirent *sd; struct iattr newattrs; int rc; - rc = -ENOENT; - victim_sd = sysfs_get_dirent(kobj->sd, attr->name); - if (!victim_sd) - goto out; + mutex_lock(&sysfs_mutex); - mutex_lock(&sysfs_rename_mutex); - victim = sysfs_get_dentry(victim_sd); - mutex_unlock(&sysfs_rename_mutex); - if (IS_ERR(victim)) { - rc = PTR_ERR(victim); - victim = NULL; + rc = -ENOENT; + sd = sysfs_find_dirent(kobj->sd, attr->name); + if (!sd) goto out; - } - - inode = victim->d_inode; - - mutex_lock(&inode->i_mutex); - newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); + newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE; - rc = sysfs_setattr(victim, &newattrs); + rc = sysfs_sd_setattr(sd, &newattrs); - mutex_unlock(&inode->i_mutex); out: - dput(victim); - sysfs_put(victim_sd); + mutex_unlock(&sysfs_mutex); return rc; } EXPORT_SYMBOL_GPL(sysfs_chmod_file);