Merge remote-tracking branch 'stefanha/block' into staging

Merge remote-tracking branch 'stefanha/block' into staging

# By Stefan Hajnoczi (4) and others
# Via Stefan Hajnoczi
* stefanha/block:
  virtio-blk: do not relay a previous driver's WCE configuration to the current
  blockdev: do not default cache.no-flush to true
  block: don't lose data from last incomplete sector
  qcow2: Correct snapshots size for overlap check
  coroutine: fix /perf/nesting coroutine benchmark
  coroutine: add qemu_coroutine_yield benchmark
  qemu-timer: do not take the lock in timer_pending
  qemu-timer: make qemu_timer_mod_ns() and qemu_timer_del() thread-safe
  qemu-timer: drop outdated signal safety comments
  osdep: warn if open(O_DIRECT) on fails with EINVAL
  libcacard: link against qemu-error.o for error_report()

Message-id: 1379698931[email protected]