[pacman-dev] [PATCH 1/2] Revert "makepkg: calculate exact total file size"

[Dave Reisner]

On Thu, Mar 15, 2012 at 07:11:07AM +1000, Allan McRae wrote:
> On 15/03/12 06:41, Dave Reisner wrote:
> > btrfs's cow snapshots seem to do very strange things, causing du to not
> > count data still in filesystem buffers. Repackaging the same build of
> > handbrake within a chroot on brynhild, I witnessed (via bash xtrace) du
> > reporting a different $pkgdir size every time the write_pkginfo()
> > function ran.
> > 
> > Unfortunately, replacing du with stat has its own slew of problems,
> > mostly due to hard links (e.g. git, with 106 hardlinks to the same
> > file). Working around this is neither fun, nor practical.
> > 
> > As it turns out, all we needed here all along was a simple call to sync
> > to flush writes to disk before calling du.
> > 
> > This reverts commit b264fb9e9ddcc31dc8782390309421965e507383.
> > 
> > Signed-off-by: Dave Reisner <dreisner at archlinux.org>
> 
> Argh...   look at the commit message in 14474a32...
> 
> That sync results in the Arch buildserver stalling for minutes.
> 
> Allan
> 

Ok fine. Back to the trenches I go...

Some careful changes to makepkg and a simple stack trace catches du in
the act of being broken. It receives a statbuf with the correct size of
/usr/bin/ghb:

  newfstatat(AT_FDCWD, "usr/bin/ghb", {st_mode=S_IFREG|0755,
  st_size=16037808, ...}, AT_SYMLINK_NOFOLLOW) = 0

And then it writes the size completely wrong:

  write(1, "3456\tusr/bin/ghb\n", 17)     = 17

I have no idea what's going on, but I'll keep digging.

d