Buffer available in memory

The simplest path involves a case where a buffer already exists for this block of the file, but might not have a strong token.

This occurs if a previous write call accessed the block and it is still resident in memory. The write token already exists from the prior call. In this case, the data is copied from the application buffer to the GPFS buffer. If this is a sequential write and the last byte has been written, an asynchronous message is sent to the daemon to schedule the buffer for writing to disk. This operation occurs on the daemon thread overlapped with the execution of the application.