Mark Lord wrote:

But there'll need to be some overlap between the old and new,
and currently the libata driver has no way for smartmontools
or hdparm to communicate and control drive features like
the cache/readahead settings, and the various SMART capabilities.

Supporting the ATA Pass-through CDB in libata will enable support for 
all of those things.  I think we all agree that there needs to be _some_ 
way of letting userspace control these attributes via direct ATA command 
submission.

As an aside, although libata _will_ support some sort of user ATA 
command execution method, some of these attributes are (or will be soon) 
available through standard SCSI methods.

For example, MODE SENSE/MODE SELECT on the caching mode page allows one 
to toggle read-ahead and writeback caching.

blktool supports both methods :)

	Jeff