Re: [PATCH] one of $BIGNUM devfs races

H. Peter Anvin
2001-08-08T21:16:42Z

Followup to: <Pine.GSO.4.21.0108071510390.18565-100000@weyl.math.psu.edu>
By author: Alexander Viro <viro@math.psu.edu>
In newsgroup: linux.dev.kernel
>
> It is not reliable. E.g. on NFS inumbers are not unique - 32 bits is
> not enough.
>

Unfortunately there is a whole bunch of other things too that rely on
it, and *HAVE* to rely on it -- (st_dev, st_ino) are defined to
specify the identity of a file, and if the current types aren't large
enough we *HAVE* to go to new types. THERE IS NO OTHER WAY TO TEST
FOR FILE IDENTITY IN UNIX, and being able to perform such a test is
vital for many things, including security and hard link detection
(think tar, cpio, cp -a.)

-hpa

--
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