Re: [sshfs] bug#6331: df reports wrong disk space usage on solaris

[Miklos Szeredi]

On Wed, 16 Jun 2010, Jim Meyering wrote:
> Miklos Szeredi wrote:
> > On Wed, 16 Jun 2010, Jim Meyering wrote:
> >> Miklos Szeredi wrote:
> >> > On Thu, 03 Jun 2010, Miklos Szeredi wrote:
> >> >> Hmm, actually "struct statfs" on linux does have f_frsize, only the
> >> >> manpage doesn't document it.  So correct thing would be to use that,
> >> >> no?
> >> >
> >> > Here's a patch that allows df(1) to correctly calculate the disk usage
> >> > and displays f_frsize in stat(1).
> >>
> >> Hi Miklos,
> >>
> >> [Cc'ing bug-gnulib, since all but src/stat.c are from gnulib]
> >>
> >> Thank you for the patch.
> >> However, I'm not sure it's portable enough.
> >> Do you know when the f_frsize member began to be useful?
> >
> > It was introduced in the linux-2.5 timeframe, so from linux-2.6.0 on
> > it contains useful information.  In 2.4.* and earlier it was part of
> > the f_spare array and was zeroed out by the kernel.
> >
> > Checking f_spare value for zero and using f_bsize instead works fine
> > for 2.4 and earlier kernels.
> 
> That sounds sufficient.
> Can you confirm that this works on a 2.4.x kernel?

Okay, after some unsuccessful attempts to run a current system with a
2.4 kernel (userspace bootup immediately fails with "FATAL: kernel too
old" message) I turned to a virtualized environment.

I compiled the patched coreutils under debian/sarge (linux-2.4.27,
glibc-2.3.6).  This glibc already has f_frsize and configure detects
it.

I then verified that df(1) and stat(1) work correctly on this system.
Then took the binaries to a 2.6 kernel and glibc-2.10.1 and verified
that they indeed take a differing f_frsize and f_bsize into account.

Thanks,
Miklos