A method, apparatus and product for accelerating concurrent access to a file in a memory-based file system. The method comprising receiving a request issued by a program, for accessing a file stored in a memory-based file system; and subject to the request being associated with data modification of data within the file, and subject to the modification not necessitating change in a structure of a data structure used for content lookup for the file, acquiring a lock to the file to the program, wherein the lock is acquired in a shared mode.