Re: Finding hardlinks
From: Mikulas Patocka
Date: Wed Jan 03 2007 - 14:17:59 EST
On Wed, 3 Jan 2007, Frank van Maarseveen wrote:
On Tue, Jan 02, 2007 at 01:04:06AM +0100, Mikulas Patocka wrote:
I didn't hardlink directories, I just patched stat, lstat and fstat to
always return st_ino == 0 --- and I've seen those failures. These failures
are going to happen on non-POSIX filesystems in real world too, very
rarely.
I don't want to spoil your day but testing with st_ino==0 is a bad choice
because it is a special number. Anyway, one can only find breakage,
not prove that all the other programs handle this correctly so this is
kind of pointless.
On any decent filesystem st_ino should uniquely identify an object and
reliably provide hardlink information. The UNIX world has relied upon this
for decades. A filesystem with st_ino collisions without being hardlinked
(or the other way around) needs a fix.
... and that's the problem --- the UNIX world specified something that
isn't implementable in real world.
You can take a closed box and say "this is POSIX cerified" --- but how
useful such box could be, if you can't access CDs, diskettes and USB
sticks with it?
Mikulas
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