block/raw-posix: create do_fallocate helper
The pattern
do {
if (fallocate(s->fd, mode, offset, len) == 0) {
return 0;
}
} while (errno == EINTR);
ret = translate_err(-errno);
will be commonly useful in next patches. Create helper for it.
CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Peter Lieven <pl@kamp.de>
CC: Fam Zheng <famz@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>