From: Christoph Hellwig <hch@xxxxxx> Date: Tue, 19 Jun 2007 07:56:29 +0200 > A SCSI pass through is of course perfectly fine. If you have a separate > block passthrough that has additional magic a separate block driver is > the way to go because it actually is simpler than a scsi driver decoding > command blocks and translating them to deep magic. The ps3 storage > drivers this thread discussed are a good example for that. We now > have a very nice and simple disk, scsi and flash chardev driver each > that don't include abstractions layers and cruft. Combine that with > their initial scsi layer driver that was full of internal dispatches > because each of these device types speaks a completely different command > set. That's how I'm currently writing my virtual disk client driver for the Sun LDOMS stuff, as a block device. The remaining issues are the partitioning (which we're discussing in another thread) and how to export the scsi passthru support in such a non-scsi block driver. The main disk I/O block read and write is done using descriptors sent to the disk server. SCSI pass-through is provided (optionally) so that disk analysis tools can do things like MODE_SENSE on the disk. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
