message: rafs: fix a bug in calculate size for io
  Fix a bug in calculate size for io.
diff: @@ -744,7 +744,7 @@ impl RafsInode for OndiskInodeWrapper {
  }
  let content_offset = (offset % chunk_size as u64) as u32;
  - let mut left = std::cmp::min(self.size(), size as u64) as u32;
  + let mut left = std::cmp::min(self.size() - offset, size as u64) as u32;
  let mut content_len = std::cmp::min(chunk_size - content_offset, left);
  let desc = self.make_chunk_io(&chunks[0], content_offset, content_len, user_io);
  