Re: [PATCH] fix cdrom mt rainier probe

[Pat LaVarre <p.lavarre@ieee.org>]

Jens A:

--- http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.8-rc1
--- ...
[PATCH] fix cdrom mt rainier probe

Mt rainier probe must be deferred to media load time, since it requires a
valid media (the drive may present a different capability based on what
media is loaded). This fixes that for ide-cd and sr.
...
---

Looks like something broke in deciding disc rewritable or not?

Only for /dev/hdd PATAPI, not for /dev/scd0 USB?

I see again we have rewritable by ioctl does not imply rewritable by dd
and mount.  I'll blog my exploration outside, then report back if I come
to understand more, but specifically so far I've seen:

$ uname -srm
Linux 2.6.7 i686
$ sudo rrd scan
/dev/scd0 is Iomega RRD 74.B rw
/dev/hdd is Iomega RRD 74.B rw
$
$ sudo dd of=/dev/scd0 bs=64K count=1 if=/dev/zero
1+0 records in
1+0 records out
$ sudo dd of=/dev/hdd bs=64K count=1 if=/dev/zero
1+0 records in
1+0 records out
$

$ uname -srm
Linux 2.6.8-rc1 i686
$ sudo rrd scan
/dev/scd0 is Iomega RRD 74.B rw
/dev/hdd is Iomega RRD 74.B rw
$
$ sudo dd of=/dev/scd0 bs=64K count=1 if=/dev/zero
1+0 records in
1+0 records out
$ sudo dd of=/dev/hdd bs=64K count=1 if=/dev/zero
dd: writing `/dev/hdd': Operation not permitted
1+0 records in
0+0 records out
$

Pat LaVarre
http://linux-pel.blog-city.com/read/728344.htm