Christoph Hellwig <hch@xxxxxx> wrote: > > + block = page->index; > > + block <<= shift; > > Can't this cause overflows? No, not unless the netfs allows files >16EiB in size and as long as block (type sector_t) is a 64-bit integer. A 16EiB-1 (0xffffffffffffffff) file would have 4P-1 (0xfffffffffffff) pages assuming a 4K page size. At a block size of 1 (and a shift therefore of 12), the maximum block number calculated would be 0xfffffffffffff000. David