-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


I recently received a bug report regarding files on an iso9660
filesystem with sizes > 2 GB. mkisofs is apparently capable of creating
these filesystems, so I did a bit of research into if this was actually
valid or not.

It seems the iso9660/ecma119 spec doesn't specify the signedness of the
"32-bit number" for which they assign space to contain the file size.
There are tests in the kernel code to disallow file sizes > 2 GB, with
the apparent reason that there was, at some point, invalid CDs floating
around that hijacked the high byte of the file size field for some other
purpose.

With DVDs becoming widely popular for personal data storage, this 2 GB
limit will probably become more and more of an issue.

Currently, if a file is > 2 GB, 'cruft mode' is enabled which strips the
high byte off a file size. Attached is a patch that adds another
condition to that test: In order to enable 'cruft mode', the file size
must be larger than the volume size. A 3 GB file on a 700 MB CD is
certainly invalid, but a 3 GB file on a 4.7 GB DVD should be valid.

Might someone with a bit more familiarity with the spec be able to
comment on this?

Thanks.

- -Jeff

- --
Jeff Mahoney
SuSE Labs
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFBGQfULPWxlyuTD7IRAqc3AJ9YC8Rg+GGmzm1V5SbHkDumkLKCvQCfSOoJ
NhagL+eCKXGugHcuFFCgZjQ=
=ToTR
-----END PGP SIGNATURE-----