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

- Make blockdev-reopen stable
- Remove deprecated qemu-img backing file without format
- rbd: Convert to coroutines and add write zeroes support
- rbd: Updated MAINTAINERS
- export/fuse: Allow other users access to the export
- vhost-user: Fix backends without multiqueue support
- Fix drive-backup transaction endless drained section

# gpg: Signature made Fri 09 Jul 2021 13:49:22 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# 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: (28 commits)
  block: Make blockdev-reopen stable API
  iotests: Test reopening multiple devices at the same time
  block: Support multiple reopening with x-blockdev-reopen
  block: Acquire AioContexts during bdrv_reopen_multiple()
  block: Add bdrv_reopen_queue_free()
  qcow2: Fix dangling pointer after reopen for 'file'
  qemu-img: Improve error for rebase without backing format
  qemu-img: Require -F with -b backing image
  qcow2: Prohibit backing file changes in 'qemu-img amend'
  blockdev: fix drive-backup transaction endless drained section
  vhost-user: Fix backends without multiqueue support
  MAINTAINERS: add block/rbd.c reviewer
  block/rbd: fix type of task->complete
  iotests/fuse-allow-other: Test allow-other
  iotests/308: Test +w on read-only FUSE exports
  export/fuse: Let permissions be adjustable
  export/fuse: Give SET_ATTR_SIZE its own branch
  export/fuse: Add allow-other option
  export/fuse: Pass default_permissions for mount
  util/uri: do not check argument of uri_free()
  ...

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