block: use int64_t instead of uint64_t in copy_range driver handlers

block: use int64_t instead of uint64_t in copy_range driver handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver copy_range handlers parameters which are already
64bit to signed type.

Now let's consider all callers. Simple

  git grep '\->bdrv_co_copy_range'

shows the only caller:

  bdrv_co_copy_range_internal(), which does bdrv_check_request32(),
  so everything is OK.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_co_copy_range_\(from\|to\)\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

shows no more callers. So, we are done.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>