On Mon, Jun 26, 2017 at 12:41 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Fri, Jun 23, 2017 at 02:19:31AM +0200, Andreas Gruenbacher wrote: >> Both ext4 and xfs implement seeking for the next hole or piece of data >> in unwritten extents by scanning the page cache, and both versions share >> the same bug when iterating the buffers of a page: the start offset into >> the page isn't taken into account, so when a page fits more than two >> filesystem blocks, things will go wrong. For example, on a filesystem >> with a block size of 1k, the following command will fail: >> >> xfs_io -f -c "falloc 0 4k" \ >> -c "pwrite 1k 1k" \ >> -c "pwrite 3k 1k" \ >> -c "seek -a -r 0" foo > > Can you wire this up for xfstests, please? I did: https://marc.info/?l=fstests&m=149817668119033 Andreas
