Block patches

# gpg: Signature made Sun 09 Feb 2014 08:12:51 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-anthony:
  block: Fix 32 bit truncation in mark_request_serialising()
  blkdebug: Don't leak bs->file on failure
  block: Don't call ROUND_UP with negative values
  block: bdrv_aligned_pwritev: Assert overlap range
  block: Fix memory leaks in bdrv_co_do_pwritev()
  raw: Fix BlockLimits passthrough
  qemu-iotests: add test for qcow2 preallocation with different cluster sizes
  qcow2: check for NULL l2meta
  qcow2: fix offset overflow in qcow2_alloc_clusters_at()
  qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset()
  block/iscsi: always fill bs->bl.opt_transfer_length
  block: Fail gracefully with missing filename
  qemu-iotests: enable support for NFS protocol
  qemu-iotests: enable test 016 and 025 to work with NFS protocol
  qemu-iotests: blacklist test 020 for NFS protocol
  qemu-iotests: change _supported_proto to file for various tests
  block: add native support for NFS
  qemu-iotest: Make 077 raw-only

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>