Re: [RFC PATCH 14/17] super->s_*_blocks_count -> ext2fs_*_blocks_count()

[Valerie Aurora Henson <vaurora@redhat.com>]

On Thu, Nov 13, 2008 at 01:24:41PM -0700, Andreas Dilger wrote:
> 
> Since it isn't yet common to be able to test > 32-bit blocks
> these bugs may go unnoticed for some time.  It would be nice to be able
> to test 64-bit support easily with e2fsprogs.  Maybe truncate file
> to > 16TB in size (abort if underlying filesystem isn't able to do this),
> use "lazy_bg" or equivalent to avoid writing many GB of data into the
> sparse file, then run e2fsck on it after putting some files at the end.
> This could probably be done by the "script" support in "make check".

Unfortunately, ext4 doesn't support a file this big so you'd have to
deliberately put your e2fsprogs tree on XFS or something like that for
this automatic check to actually help - not a terribly common
situation for an e2fsprogs developer. (I'm doing all my testing on
sparse files on XFS, which definitely chafes - nothing wrong with XFS,
just kind of annoying that I can't self-host e2fsprogs development.)

Hummm... Would it work to use LVM to glue together two loopback
devices backed by files that sum to just over 16TB?

-VAL