qemu: block: Add universal helper for merging dirty bitmaps for all scenarios
Add a function which allows merging bitmaps according to the new
semantics and will allow replacing all the specific ad-hoc functions
currently in use for 'backup', 'block commit', 'block copy' and will
also be usable in the future for 'block pull' and non-shared storage
migration.
The semantics are a bit quirky for the 'backup' case but these quirks
are documented and will prevent us from having two slightly different
algorithms.
Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
projects / libvirt.git / commit