Ming Zhang wrote: > On Tue, 2005-09-20 at 13:27 -0500, Mike Christie wrote: > >>Mike Christie wrote: >> >>>Ming Zhang wrote: >>> >>> >>>>Hi Mike >>>> >>>>I think change vsd->vdev is a bad idea. >>> >>> >>>I would agree it is a bad name, but all that device does today is the >>>reads and writes. It should probably be called something-something-IO. >>> From your experience with iet, do you think a read or write will be >>>different for tape or disk when using the interface we are using? >>> >> >>Oh yeah, I had looked at scst's dev_handlers for an example. I think >>mostly only the error hanlding will be a problem. > > > yes, that is quite different. > So I guess we will need something. Originally the vsd and sd names came about becuase we were only doing SCSI and vsd was a virtual scsi disk and sd was a scsi disk passthrough type of device. They basically emulated SCSI's ULDs for tape, cd, disk but they also performed different types of IO, passthrough vs generic_file_readv/writev. Eventually we pushed the SCSI stuff to the protocol handlers and the devices became what they are today. Maybe io_handlers or io_type is a better name? Then to suport scsi tape, cd, etc we can add that code to the scsi protocol and have something simialr to the SCSI-ml ULDs. |