[Qemu-devel] Re: [PATCH] scsi: Make device scsi-disk reject /dev/sg*

[Markus Armbruster]

Gerd Hoffmann <address@hidden> writes:

> On 02/25/10 11:23, Markus Armbruster wrote:
>> You're supposed to use scsi-generic for that.  Which rejects anything
>> but /dev/sg*.
>
> Well, it isn't *that* easy.  The SG_IO ioctl used by scsi-generic
> works on tons of devices in linux, not only /dev/sg*.  I've seen

Yes, the existing check in scsi-generic is pretty cheesy.  My patch just
makes scsi-disk consistently cheesy ;)

> patches floading around which change the check bdrv_is_sg() into "try
> SG_IO and see if it works", which would allow to use /dev/sda with
> both scsi-disk and scsi-generic depending on what you want.  Which
> makes alot of sense.
>
> Making that change needs some extra care though to avoid existing
> configurations switching from scsi-disk to scsi-generic unnoticed.

Would be nice to have some day.