[dm-devel] no INQUIRY from userspace please (was Re: [PATCH 7/9] scsi_dh: Add support for SDEV_PASSIVE)

Stefan Richter stefanr at s5r6.in-berlin.de
Thu Feb 7 10:08:24 UTC 2008


Mike Anderson wrote:
> A number of user apps like lvm scanning that execute media access commands
> already have filter capability to filter devices that one does not want to
> scan. Another class of device scanners just use inquiries which are not
> effected by the passive state (though some could probably use udevinfo and
> reduce the amount of repeated SCSI inquiries execute on the system.

To expand on this:

At least on desktop systems and SOHO server systems, userspace should
_never_ issue INQUIRY.  There are too many broken firmwares out there
which assume that there will never be more than one INQUIRY sent.  They
start to return garbled data or crash if they get a second INQUIRY.
-- 
Stefan Richter
-=====-==--- --=- --===
http://arcgraph.de/sr/




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