sysfs: fix locking in sysfs_lookup() and sysfs_rename_dir()

sd children list walking in sysfs_lookup() and sd renaming in
sysfs_rename_dir() were left out during i_mutex -> sysfs_mutex
conversion. Fix them.

Signed-off-by: Tejun Heo <[e-mail]>
Acked-by: Cornelia Huck <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

fs/sysfs/dir.c

···
 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 				struct nameidata *nd)
 {
+	struct dentry *ret = NULL;
 	struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
 	struct sysfs_dirent * sd;
 	struct bin_attribute *bin_attr;
 	struct inode *inode;
 	int found = 0;
+
+	mutex_lock(&sysfs_mutex);
 
 	for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
 		if (sysfs_type(sd) &&
···
 
 	/* no such entry */
 	if (!found)
-		return NULL;
+		goto out_unlock;
 
 	/* attach dentry and inode */
 	inode = sysfs_get_inode(sd);
-	if (!inode)
-		return ERR_PTR(-ENOMEM);
-
-	mutex_lock(&sysfs_mutex);
+	if (!inode) {
+		ret = ERR_PTR(-ENOMEM);
+		goto out_unlock;
+	}
 
 	if (inode->i_state & I_NEW) {
 		/* initialize inode according to type */
···
 	sysfs_instantiate(dentry, inode);
 	sysfs_attach_dentry(sd, dentry);
 
+ out_unlock:
 	mutex_unlock(&sysfs_mutex);
-
-	return NULL;
+	return ret;
 }
 
 const struct inode_operations sysfs_dir_inode_operations = {
···
 	if (error)
 		goto out_drop;
 
+	mutex_lock(&sysfs_mutex);
+
 	dup_name = sd->s_name;
 	sd->s_name = new_name;
 
 	/* move under the new parent */
 	d_add(new_dentry, NULL);
 	d_move(sd->s_dentry, new_dentry);
-
-	mutex_lock(&sysfs_mutex);
 
 	sysfs_unlink_sibling(sd);
 	sysfs_get(new_parent_sd);