block/copy-before-write.h: global state API + assertions

copy-before-write functions always run under BQL.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220303151616.325444-24-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2 files changed