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To: gurney_j@resnet.uoregon.edu
From: "M. Warner Losh" <imp@bsdimp.com>
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Cc: pjd@freebsd.org, freebsd-arch@freebsd.org
Subject: Re: Accessing disks via their serial numbers.
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In message: <20060626031636.GK82074@funkthat.com>
            John-Mark Gurney <gurney_j@resnet.uoregon.edu> writes:
: Warner Losh wrote this message on Sun, Jun 25, 2006 at 17:48 -0600:
: > In message: <20060624174331.GB2134@garage.freebsd.pl>
: >             Pawel Jakub Dawidek <pjd@freebsd.org> writes:
: > : I'd like to extend glabel(8) to create providers related to disks based
: > : on their serial numbers and everntually driver name.
: > : For example disk ad0 could also be accessed via /dev/disk/ata/3JX0LMGA
: > : (/dev/disk/<driver>/<serial> or /dev/disk/<serial>).
: > 
: > /dev/disk/ad/3JX0LMGA or /dev/disk/da/3JX0LMGA is the only thing
: > you'll be able to do.  There's no mapping from the dev_t -> device_t,
: > so you have no way of knowing what the parent of the disk's dev_t.
: > All the I/O in the system is done with dev_t's.
: > 
: > Also, the cam system doesn't hook into the newbus system due to when
: > it was authored.  There's been some resistance to moving the scsi
: > devices into the device_t tree, like all other storage devices.  This
: > is part of the problem indoing thinging completely generically.
: 
: Can't we expand the disk api?  add a const char *d_serial to the struct
: disk, and have the disk api automaticly propegate the serial number up
: to the geom layer?

We could do that, yes.  However, that's hardly generic...

Warner