diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 6f21adf9479af7602009a736b5cede2b820db79c..d9b0e92b36021f235b00fa9549c865de5eee26af 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -720,8 +720,10 @@ static ssize_t jfs_quota_write(struct super_block *sb, int type,
 		blk++;
 	}
 out:
-	if (len == towrite)
+	if (len == towrite) {
+		mutex_unlock(&inode->i_mutex);
 		return err;
+	}
 	if (inode->i_size < off+len-towrite)
 		i_size_write(inode, off+len-towrite);
 	inode->i_version++;