[PATCH] sysfs: add sysfs_chmod_file()
sysfs: allow changing the permissions for already created attributes
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 352f966..da25aeb 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -428,6 +428,41 @@
/**
+ * sysfs_chmod_file - update the modified mode value on an object attribute.
+ * @kobj: object we're acting for.
+ * @attr: attribute descriptor.
+ * @mode: file permissions.
+ *
+ */
+int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
+{
+ struct dentry *dir = kobj->dentry;
+ struct dentry *victim;
+ struct sysfs_dirent *sd;
+ umode_t umode = (mode & S_IALLUGO) | S_IFREG;
+ int res = -ENOENT;
+
+ down(&dir->d_inode->i_sem);
+ victim = sysfs_get_dentry(dir, attr->name);
+ if (!IS_ERR(victim)) {
+ if (victim->d_inode &&
+ (victim->d_parent->d_inode == dir->d_inode)) {
+ sd = victim->d_fsdata;
+ attr->mode = mode;
+ sd->s_mode = umode;
+ victim->d_inode->i_mode = umode;
+ dput(victim);
+ res = 0;
+ }
+ }
+ up(&dir->d_inode->i_sem);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(sysfs_chmod_file);
+
+
+/**
* sysfs_remove_file - remove an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.