On Wed, Nov 08, 2023 at 10:08:27AM -0800, Darrick J. Wong wrote: > On Wed, Nov 08, 2023 at 06:53:20PM +0100, Christoph Hellwig wrote: > > search_rt_dup_extent takes a xfs_rtblock_t, not an RT extent number. > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > --- > > > > What scares me about this is that no test seems to hit this and report > > false duplicates. I'll need to see if I can come up with an > > artifical reproducers of some kind. > > I think you've misread the code -- phase 4 builds the rt_dup tree by > walks all the rtextents, and adding the duplicates: Hmm. So yes, add_rt_dup_extent seems to be called on an actual rtext, but scan_bmapbt calls search_rt_dup_extent with what is clearly a fsbno_t. So something is fishy here for sure.. > So I think the reason why you've never seen false duplicates is that the > rt_dup tree intervals measure rt extents, not rt blocks. The units > conversion in process_rt_rec_dups is correct. Note that I don't see error with the patch either, so either way the coverage isn't good enough..
