[Qemu-devel] [PATCH 0/4] block: Avoid copy-on-read assertions

[Eric Blake]

During my quest to switch block status to be byte-based, John
forced me to evaluate whether we have a situation during
copy-on-read where we could exceed BDRV_REQUEST_MAX_BYTES [1].
Sure enough, we have a number of pre-existing bugs in the
copy-on-read code.  Fix those (patch 3), along with adding a
test (patch 4, but needs a couple of additions in patch 1 and
2 to make the test even possible).  Swapping patch 3 and 4
demonstrates that the test indeed exposes flaws.

[1] https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg07286.html

Eric Blake (4):
  qemu-io: Add -C for opening with copy-on-read
  block: Add blkdebug hook for copy-on-read
  block: Perform copy-on-read in loop
  iotests: Add test 197 for covering copy-on-read

 qapi/block-core.json             |   5 +-
 block/io.c                       | 118 +++++++++++++++++++++++++++------------
 qemu-io.c                        |  15 ++++-
 tests/qemu-iotests/common.filter |   1 +
 tests/qemu-iotests/197           |  93 ++++++++++++++++++++++++++++++
 tests/qemu-iotests/197.out       |  24 ++++++++
 tests/qemu-iotests/group         |   1 +
 7 files changed, 216 insertions(+), 41 deletions(-)
 create mode 100755 tests/qemu-iotests/197
 create mode 100644 tests/qemu-iotests/197.out

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2.13.6