Re: [prepatch] address_space-based writeback

Peter Wächtler (pwaechtler@loewe-komp.de)
Tue, 30 Apr 2002 18:12:37 +0200


john slee wrote:
> [ cc list trimmed ]
>
> On Tue, Apr 30, 2002 at 03:19:17PM -0200, Denis Vlasenko wrote:
>
>>Why do we have to stich to concept of inode *numbers*?
>>Because there are inode numbers in traditional Unix filesystems?
>>
>
> probably because there is software out there relying on them being
> numbers and being able to do 'if(inum_a == inum_b) { same_file(); }'
> as appropriate. i can't think of a use for such a construct other than
> preserving hardlinks in archives (does tar do this?) but i'm sure there
> are others
>
> like much of unix it's been there forever and has become such a natural
> concept in people's heads that to change it now seems unthinkable.
>
> much like the missing e in creat().
>

No. Not supplying inode numbers would break unix semantics.
The kernel (and binary loader) depends on a unique key:

major:minor device number + inode

Otherwise: how to decide if a shared object is the same?
checksuming? ;-)

But what would be different with characters? Despite more complexity?

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