1. A method comprising: receiving a data write request to write a block of data from a volatile memory to a non-volatile memory in an in-place-update file system of a deduplication computing system; determining whether the data write request is to perform an in-place update of an existing block in the non-volatile memory; when the data write request is to perform the in-place update of the existing block, converting a type of write operation associated with the request from a requested write operation type to a new data allocation write operation; and processing the new data allocation write operation to write the block of data from the volatile memory to the non-volatile memory using an ordered sequence of file system data journaling and writes to the non-volatile memory.