Re: 2.9test9-mm1 and DAO ATAPI cd-burning corrupt

Linus Torvalds
2003-11-11T22:04:24Z

On Tue, 11 Nov 2003, Pascal Schmidt wrote:
>
> dd behaves strangly on the MO drive. I've tried with 2.6.0-test9 and
> the patch appended to the end of this mail.
>
> # dd if=testfile of=/dev/hde bs=4096 count=1
> dd: writing `/dev/hde': no space left on device
> 1+0 records in
> 0+0 records out
>
> # dd if=/dev/hde of=mofile bs=4096 count=1
> 0+0 records in
> 0+0 records out
>
> Mounting the disc read-only works, however, and I can read all the data
> on it without problems.

Ok, that's just strange. You can't even _read_ from the raw device, but
the mount works ok?

And you got no IO errors anywhere? I don't see why the write would fail
silently.

I wonder whether the disk capacity is set to zero. See
drivers/ide/ide-cd.c, and in particular the

/* Now try to get the total cdrom capacity. */
stat = cdrom_get_last_written(cdi, (long *) &toc->capacity);
if (stat || !toc->capacity)
stat = cdrom_read_capacity(drive, &toc->capacity, sense);
if (stat)
toc->capacity = 0x1fffff;

and see what that says.. I really think you should start sprinkling
printk's around the thing to determine what goes on..

Linus