linux-ext4 - Re: Difference in statvfs(2) block count with ext2 and very recent Linux 3.2.0 kernels

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Message-ID: <20111116164356.GT2626@amd.home.annexia.org>
Date:	Wed, 16 Nov 2011 16:43:56 +0000
From:	"Richard W.M. Jones" <rjones@...hat.com>
To:	Eric Sandeen <sandeen@...hat.com>
Cc:	linux-ext4@...r.kernel.org, meyering@...hat.com
Subject: Re: Difference in statvfs(2) block count with ext2 and very recent
 Linux 3.2.0 kernels

On Wed, Nov 16, 2011 at 10:33:19AM -0600, Eric Sandeen wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 11/16/11 3:54 AM, Richard W.M. Jones wrote:
> > 
> > Hi,
> > 
> > We do some automated testing of the kernel and ext2/3/4 filesystems,
> > and noticed that the block count returned by statvfs(2) for plain
> > *ext2* filesystems has changed with the latest 3.2.0rc1 kernel.
> > 
> > This is probably just because of more accurate block accounting, but I
> > just wanted to check that it isn't a bug.
> > 
> > This posting contains the numbers and a reproducer:
> > 
> >   https://www.redhat.com/archives/libguestfs/2011-November/msg00051.html
> > 
> > Rich.
> > 
> 
> Note that it is a plain *ext2* filesystem run through the *ext4* driver,
> in Fedora,

Correct!  We're using CONFIG_EXT4_USE_FOR_EXT23=y.

> and it was tracked down to commit f975d6bcc7a698a10cc755115e27d3612dcfe322
> ext4: teach ext4_statfs() to deal with clusters if bigalloc is enabled
> according to the above post...

Well, that's what I thought looked likely.  However I didn't bisect
this, so it could be another commit to blame ...

Rich.

-- 
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