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

Block layer patches

- Fix permission update order problems with block graph changes
- qemu-img convert: Unshare write permission for source
- vhost-user-blk: Fail gracefully on too large queue size

# gpg: Signature made Fri 30 Apr 2021 11:27:51 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: (39 commits)
  vhost-user-blk: Fail gracefully on too large queue size
  qemu-img convert: Unshare write permission for source
  block: Add BDRV_O_NO_SHARE for blk_new_open()
  block: refactor bdrv_node_check_perm()
  block: rename bdrv_replace_child_safe() to bdrv_replace_child()
  block: refactor bdrv_child_set_perm_safe() transaction action
  block: inline bdrv_replace_child()
  block: inline bdrv_check_perm_common()
  block: drop unused permission update functions
  block: bdrv_reopen_multiple: refresh permissions on updated graph
  block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepare
  block: add bdrv_set_backing_noperm() transaction action
  block: make bdrv_refresh_limits() to be a transaction action
  block: make bdrv_unset_inherits_from to be a transaction action
  block: drop ignore_children for permission update functions
  block/backup-top: drop .active
  block: introduce bdrv_drop_filter()
  block: add bdrv_remove_filter_or_cow transaction action
  block: adapt bdrv_append() for inserting filters
  block: split out bdrv_replace_node_noperm()
  ...

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