Messages in this thread | | | Date | Mon, 18 Jun 2007 23:07:31 -0700 (PDT) | Subject | Re: [patch 4/6] ps3: Disk Storage Driver | From | David Miller <> |
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From: Christoph Hellwig <hch@lst.de> 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-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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