[Qemu-block] [PATCH v12 0/2] mirror: Improve zero write and discard

[Fam Zheng]

v12: Treat target cluster size as BDRV_SECTOR_SIZE if bdrv_get_info failed or
     doesn't set bdi.cluster_size;

v11: Rebase. The only difference is the "file" parameter of
     bdrv_get_block_status_above.

Patch 1 rewrites mirror_iteration. Patch 2 is a small DRY cleaning up.

The main benefit is copying unallocated sectors (both zeroed and discarded)
doesn't go through the iov setup loop, as they don't need it.

Fam Zheng (2):
  mirror: Rewrite mirror_iteration
  mirror: Add mirror_wait_for_io

 block/mirror.c             | 353 +++++++++++++++++++++++++++------------------
 tests/qemu-iotests/109.out |  80 +++++-----
 trace-events               |   1 -
 3 files changed, 252 insertions(+), 182 deletions(-)

-- 
2.4.3