[Qemu-block] [PATCH v3 0/5] qcow2_co_write_zeroes and related improvements

[Eric Blake]

This series improves write_zeroes for qcow2

Since the work conflicts with my proposed patches to switch
write_zeroes to a byte-base interface, I figured I'd fix the
bugs and get this part nailed first, then rebase my other
work on top, rather than making Denis have to do the dirty work.

Changes from v2:
- patch 1: close to a rewrite, same concept but in fewer lines
of code, and with testsuite change to back it up as valid; but
keep authorship
- patch 2, 3: unchanged
- patch 4 from original series already applied
- patch 4 in this series is new
- patch 5: rewrite of the original v5 that catches even more
cases; claim authorship

[hmm, maybe I should treat 1 and 5 the same on whether to leave
authorship unchanged or just credit Denis for the original idea]

Denis V. Lunev (3):
  block: split write_zeroes always
  qcow2: simplify logic in qcow2_co_write_zeroes
  qcow2: add tracepoints for qcow2_co_write_zeroes

Eric Blake (2):
  qemu-iotests: Test one more spot for optimizing write_zeroes
  qcow2: Catch more unaligned write_zero into zero cluster

 block/io.c                 | 30 ++++++++++++---------
 block/qcow2.c              | 67 ++++++++++++++++++++--------------------------
 tests/qemu-iotests/154     | 40 +++++++++++++++++++++++++++
 tests/qemu-iotests/154.out | 55 ++++++++++++++++++++++++++++++++-----
 trace-events               |  2 ++
 5 files changed, 137 insertions(+), 57 deletions(-)

-- 
2.5.5