Re: SCSI device numbering (was: Re: Ideas for v2.1

Stephen C. Tweedie (sct@dcs.ed.ac.uk)
Thu, 27 Jun 1996 11:52:56 +0100


Hi,

On Sat, 22 Jun 1996 21:06:39 +0200, Andries.Brouwer@cwi.nl said:

> Eric Youngdale:
> : .... Clearly a larger
> : dev_t is needed, no matter how we do it. We need to somehow agree on how
> : large this needs to be, and *then* we need to fix the filesystems so that
> : they store a dev_t that is this large.

> Yes. I think we do not have very much choice:
> POSIX requires dev_t to be an arithmetic type (so it cannot be a struct),
> which on Intel limits us to 64 bits.
> Since changing is slow and painful it seems a bad idea to go to 32 bits
> and have to change again a few years later.
> On the other hand, not many C compilers support long long, so a 64-bit
> dev_t would limit us to gcc. I don't know whether that would be a
> problem for anybody.

One word of warning --- this will break POSIX. "gcc -ansi
-pedantic-errors" will not compile code with long long declarations.
Any truly, strictly ANSI environment won't be able to compile programs
referencing a 64-bit dev_t.

Cheers,
Stephen.

--
Stephen Tweedie <sct@dcs.ed.ac.uk>
Department of Computer Science, Edinburgh University, Scotland.