Merge remote-tracking branch 'remotes/vsementsov/tags/pull-jobs-2021-06-25' into...

Merge remote-tracking branch 'remotes/vsementsov/tags/pull-jobs-2021-06-25' into staging

block: Make block-copy API thread-safe

# gpg: Signature made Fri 25 Jun 2021 13:40:24 BST
# gpg:                using RSA key 8B9C26CDB2FD147C880E86A1561F24C1F19F79FB
# gpg: Good signature from "Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8B9C 26CD B2FD 147C 880E  86A1 561F 24C1 F19F 79FB

* remotes/vsementsov/tags/pull-jobs-2021-06-25:
  block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
  block-copy: add CoMutex lock
  block-copy: move progress_set_remaining in block_copy_task_end
  block-copy: streamline choice of copy_range vs. read/write
  block-copy: small refactor in block_copy_task_entry and block_copy_common
  co-shared-resource: protect with a mutex
  progressmeter: protect with a mutex
  blockjob: let ratelimit handle a speed of 0
  block-copy: let ratelimit handle a speed of 0
  ratelimit: treat zero speed as unlimited

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