Re: LEAST SURPRISE
Daniel Quinlan writes:
> Sorry. What if you are mounting different partitions? You need to
> mount with the BSD option each and every time you mount to have "least
> surprise" or whatever.
And so ? I don't think that this is a real problem. At my
university we have lots of Sun workstations and we need the BSD
semantics. Every time a new workstation is installed, I simply add
the `grpid' mount option to every filesystem in /etc/fstab and I simply
forget about it (until the next system installation).
> Humpf. Just change to another directory with the same permissions even
> and then get different behavior -- that'll send 'em to c.o.l.help!
You can already get different semantics if you use different
partitions. If two partitions contain different types of filesystems,
the semantics may be different (e.g. filenames lengths, access rights).
For Joe user, there is no way to know that he is currently using a
minix or ext2 filesystem (and he may not even know about the existence
of different filesystems types).
> I'd rather it was just the default Linux behavior, but it isn't going
> to happen.
Ah ? What makes you say that ?
About two months ago, I have sent a query to the KERNEL channel
of the Linux Activists mailing list. In this query, I had asked other
hackers if the default behavior of the ext2fs should be BSD or SV like.
There was no real answer so I did not change the default behavior of
ext2fs but, if there is a need, I am willing to make this change in the
next version (it is quite easy: I have only one line to change in the
ext2fs kernel code). BTW, BSD semantics seem more logical to me so I
think that I'll do the change someday anyway.
> I wish that we didn't have to even think about mucking
> around with /etc/group. Anyway, the fact of the matter is that I'm not
> even convinced that we want it. We will be getting good benefits, but
> the drawbacks are undeniable. My mere question is: if the benefits are
> so undeniable, why can't this change occur everywhere and not just
> Debian?
The change has not been made in other Un*ces and other Linux
distributions because this change is simply not needed. Please see
my mail in debian-user about the uid==gid proposal. In this mail, I
explain that a common project involving several developers does not
imply write access to the common files for every developer.
> If the Linux community (or a significant majority) felt that
> this is a good change and Linus agreed, could we have a low-level
> change in directory semantics?
Changing the directory semantics is quite easy in ext2fs (the code
is already in and only needs to be flagged as the default behavior). Adding
BSD semantics to other filesystems should also be obvious. I'd be able to
change the directory semantics in every filesystem in less than one hour so
if there is a need for it and no major objection, just tell me. BTW, don't
forget that this is, IMO, unrelated to the common project scheme.
> I don't think POSIX defines anything in this area, but I haven't checked.
Posix allows both BSD and SV semantics, so either behavior is
acceptable. FIPS-151 requires BSD semantics.
>
> Dan
>
> --
> Daniel Quinlan <quinlan@spectrum.cs.bucknell.edu>
>
Remy
Reply to: