Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qcow2: Allow overwriting multiple compressed clusters at once for
  better performance
- nfs: add support for nfs_umount
- file-posix: write_zeroes fixes
- qemu-io, blockdev-create, pr-manager: Fix crashes and memory leaks
- qcow2: Fix the calculation of the maximum L2 cache size
- vpc: Fix return code for vpc_co_create()
- blockjob: Code cleanup
- iotests improvements (e.g. for use with valgrind)

# gpg: Signature made Fri 13 Sep 2019 11:19:19 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (23 commits)
  qcow2: Stop overwriting compressed clusters one by one
  block/create: Do not abort if a block driver is not available
  qemu-io: Don't leak pattern file in error path
  iotests: extend sleeping time under Valgrind
  iotests: extended timeout under Valgrind
  iotests: Valgrind fails with nonexistent directory
  iotests: Add casenotrun report to bash tests
  iotests: exclude killed processes from running under Valgrind
  iotests: allow Valgrind checking all QEMU processes
  block/nfs: add support for nfs_umount
  block/nfs: tear down aio before nfs_close
  iotests: skip 232 when run tests as root
  iotests: Test blockdev-create for vpc
  iotests: Restrict nbd Python tests to nbd
  iotests: Restrict file Python tests to file
  iotests: Add supported protocols to execute_test()
  vpc: Return 0 from vpc_co_create() on success
  file-posix: Fix has_write_zeroes after NO_FALLBACK
  pr-manager: Fix invalid g_free() crash bug
  iotests: Test reverse sub-cluster qcow2 writes
  ...

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