Merge remote-tracking branch 'kwolf/for-anthony' into staging

* kwolf/for-anthony:
  qemu-iotests: Fix 030 after switch to GenericError
  block: Flush parent to OS with cache=unsafe
  iscsi: Fix NULL dereferences / races between task completion and abort
  monitor: Clean up fd sets on monitor disconnect
  block: Enable qemu_open/close to work with fd sets
  block: Convert close calls to qemu_close
  block: Convert open calls to qemu_open
  block: Prevent detection of /dev/fdset/ as floppy
  qapi: Introduce add-fd, remove-fd, query-fdsets
  qemu-char: Add MSG_CMSG_CLOEXEC flag to recvmsg