Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-11-04' into staging

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-11-04' into staging

Block patches for 4.2-rc0:
- Work around XFS write-zeroes bug in file-posix block driver
- Fix backup job with compression
- Fix to the NVMe block driver header

# gpg: Signature made Mon 04 Nov 2019 09:01:16 GMT
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-11-04:
  block/file-posix: Let post-EOF fallocate serialize
  block: Add bdrv_co_get_self_request()
  block: Make wait/mark serialising requests public
  block/block-copy: fix s->copy_size for compressed cluster
  nvme: fix NSSRS offset in CAP register

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