[Qemu-devel] [PATCH v2 00/21] qcow2: Rework cluster allocation even more

[Kevin Wolf]

This is the start of the latest Delayed COW series. As there seem to be serious
problems with the actual Delayed COW (which in fact exist today, but would
become a bit easier to hit) and I don't have the time to complete this at the
moment, here is another series with preparatory patches, for which there's no
reason to not get them applied now.

The result is a somewhat cleaner cluster allocation code in qcow2, and in
theory some cases should show improved performance - in practice I think these
cases are unlikely to occur, but as the optimisation falls out naturally, let's
just take it.

Kevin Wolf (21):
  qemu-iotests: More concurrent allocation scenarios
  qcow2: Fix "total clusters" number in bdrv_check
  qcow2: Remove bogus unlock of s->lock
  qcow2: Handle dependencies earlier
  qcow2: Improve check for overlapping allocations
  qcow2: Change handle_dependency to byte granularity
  qcow2: Decouple cluster allocation from cluster reuse code
  qcow2: Factor out handle_alloc()
  qcow2: handle_alloc(): Get rid of nb_clusters parameter
  qcow2: handle_alloc(): Get rid of keep_clusters parameter
  qcow2: Finalise interface of handle_alloc()
  qcow2: Clean up handle_alloc()
  qcow2: Factor out handle_copied()
  qcow2: handle_copied(): Get rid of nb_clusters parameter
  qcow2: handle_copied(): Get rid of keep_clusters parameter
  qcow2: handle_copied(): Implement non-zero host_offset
  qcow2: Prepare handle_alloc/copied() for byte granularity
  qcow2: Use byte granularity in qcow2_alloc_cluster_offset()
  qcow2: Allow requests with multiple l2metas
  qcow2: Move cluster gathering to a non-looping loop
  qcow2: Gather clusters in a looping loop

 block/qcow2-cluster.c      | 507 ++++++++++++++++++++++++++++++++-------------
 block/qcow2-refcount.c     |   4 +-
 block/qcow2.c              |  16 +-
 block/qcow2.h              |  29 +++
 tests/qemu-iotests/038.out |  10 +-
 tests/qemu-iotests/044.out |   4 +-
 tests/qemu-iotests/046     |  49 ++++-
 tests/qemu-iotests/046.out |  76 +++++++
 trace-events               |   2 +
 9 files changed, 534 insertions(+), 163 deletions(-)

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1.8.1.4