kern/121686: [ata]: bogus CHS to LBA mapping in (at least) ata

[David Schultz]

This is a problem with some CD-ROMs, too, except in the case of
CD-ROMs, the problem is more fundamental: the official standard
allows the drive to overestimate the disc's capacity by a few
sectors. GEOM just exacerbates the problem by having a dozen
different providers each try to read the last sector. The latter
issue has been discussed and the general reaction is that it's
undesirable to force GEOM providers to cope with misbehaving
devices.

The fact that these errors result in a timeout in FreeBSD but not
under (at least) Solaris makes me wonder whether there isn't a
better way for the ata driver to notice the error than a timeout.
Then again, I'm not an expert on ata.