Direct access to de-duplicated data units in memory-based file systems

A computer program product comprising a non-transient computer readable storage medium retaining program instructions, which program instructions when read by a processor, cause the processor to perform a method comprising:

• updating a page entry in a page table of a process to include a direct access pointer to a de-duplicated data unit retained by a memory-based file system, wherein the page entry is set to be write protected;
• detecting a page fault occurring due to the process performing a store instruction to the de-duplicated data unit;
• and
• in response to said detecting:
• allocating a new data unit;
• copying content of the de-duplicated data unit to the new data unit;
• and
• replacing the direct access pointer to the de-duplicated data unit with a direct access pointer to the new data unit.

An apparatus comprising a processor and memory, wherein the memory retaining a memory-based file system, wherein said processor is configured to perform a method comprising:

• updating a page entry in a page table of a process to include a direct access pointer to a de-duplicated data unit retained by a memory-based file system, wherein the page entry is set to be write protected;
• detecting a page fault occurring due to the process performing a store instruction to the de-duplicated data unit;
• and
• in response to said detecting:
• allocating a new data unit;
• copying content of the de-duplicated data unit to the new data unit;
• and
• replacing the direct access pointer to the de-duplicated data unit with a direct access pointer to the new data unit.