linux-ext4 - Re: Question on huge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 10 Jul 2009 10:39:19 -0500
From:	Eric Sandeen <sandeen@...hat.com>
To:	Curt Wohlgemuth <curtw@...gle.com>
CC:	ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: Question on huge_file

Curt Wohlgemuth wrote:
> I apologize if this is a dumb question, but I'm having trouble
> understanding the huge_file superblock flag.
> 
> I see how, if this flag is set, that the inode can have a size > 2**32
> bytes, using the i_size_lo/i_size_high fields.
> 
> But since an ext4_extent only uses 32-bits for for its ee_block field
> to represent the logical block, how can an extent describe any block
> range of a file past the 4GiB boundary?
> 
> Am I missing something?

i_size_lo/hi is in bytes, ee_block is in .... blocks.

so 2^32 blocks is a lot more than 2^32 bytes, and i_size_hi/lo are
needed to contain it.  I think.  :)

-Eric
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html