<4> post_create: setxatter failed

[Russell Coker]

On Thursday 26 May 2005 02:05, Hans Reiser <reiser at namesys.com> wrote:
> > Finally, are there still known situations where a corrupt ReiserFS file
> >
> >
> >They were reported years ago on the ReiserFS list.  Hans didn't seem
> > inclined to fix them as fixing such bugs incurred a performance penalty.
> >
> >If that policy has changed in the ReiserFS development team then I'll
> > write some scripts to randomly corrupt ReiserFS file systems and try to
> > reproduce kernel bugs.
>
> I don't know which bugs you are referring to, and I don't remember
> saying what you ascribe to me.  Perhaps you refer to my not fscking each
> node after it is read into memory before it is used by the filesystem.
> I don't think anybody does that, not just us.  Some checks are made by
> us, but a complete and exhaustive check is not made by anyone that I
> know of.  We could probably write a node plugin that would crc check
> after the node is read from disk.  That would be reasonable, and I would
> accept a node plugin to do that.

I don't know the exact cause of the bug in terms of which part of the code was 
responsible.

I reported a bug where I had a file system which if mounted would have a 
"find /" operation cause a kernel Oops.  As far as I am aware the bug in 
question was never fixed.

It is my belief and the belief of many other people that a corrupted file 
system should not be able to corrupt kernel memory, not even if the file 
system is maliciously generated (think about the case of an attacker 
inserting a CD or USB disk).  I am not aware of any other Linux file system 
for which a corrupted partition can cause kernel memory corruption (please 
inform me if you know of one).

As for the "complete and exhaustive check", maybe this is an advantage for a 
file system based on Inode tables as the data structures are simpler and 
easier to check?

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