Use a much larger buffer for message log retrieval until we are sure that 32 bytes is safe.
Use a much larger buffer for message log retrieval until we are sure that
32 bytes is safe.

Handle successful completion of message log retrieval commands.

With these changes, the driver correctly handles the consequences of drive
death and replacement in a reliable array.  Note that the massive backlog
of I/O during handling of such an event can kill the system if softupdates
is enabled.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase