Device minor number uniqueness

[Poul-Henning Kamp]

In message <20080217212457.GX1340 at hoeg.nl>, Ed Schouten writes:

>After digging into some more source code, it turns out a lot of drivers
>use minor number to store device numbers and such, but there is no real
>reason why we should enforce drivers to use unique minor numbers.

the major & minor together combine to the userland concept of a
"dev_t" which conforms to POSIX.

While I don't think POSIX demands that dev_t has to be unique per
device, the amount of software that assumes them to be is not to
be sneezed at.

If you just need a minor number to fill out the field, use the
unit number allocation functions.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.