btrfs and git-reflog

I was just playing with git 1.5.3.8 and btrfs 0.11, and I noticed something odd.

If I prepare a very simple repository:

  $ mkdir foo
  $ cd foo
  $ git init
  Initialized empty Git repository in .git/
  $ echo hi > blort
  $ git add .
  $ git commit -m create
  Created initial commit 4ae9415: create
   1 files changed, 1 insertions(+), 0 deletions(-)
   create mode 100644 blort

and then attempt to expire the reflogs

  $ git-reflog --expire --all

on ext3, git-reflog completes its work and exits immediately;

and on btrfs, it gets stuck in some sort of loop that causes it to allocate more and more memory until I kill it or it pushes the machine into OOM.

Kernel is 2.6.24 or so on x86-64.