On Mon, Feb 11, 2019 at 03:51:44PM -0800, Darrick J. Wong wrote: > > The comparism pass before the sync might see an "error" if we use COW > > fork speculative preallocations for non-overwrites, which is useful to > > reduce fragmentation. > > What error do you see? -- /root/xfstests/tests/xfs/420.out 2019-02-12 15:41:12.202606228 +0000 +++ /root/xfstests/results//xfs/420.out.bad 2019-02-12 18:58:06.158426573 +0000 @@ -14,8 +14,6 @@ Whence Result DATA 0 HOLE 131072 -DATA 196608 -HOLE 262144 Compare files c2803804acc9936eef8aab42c119bfac SCRATCH_MNT/test-420/file1 017c08a9320aad844ce86aa9631afb98 SCRATCH_MNT/test-420/file2 > > -echo "Seek holes and data in file1" > > -$XFS_IO_PROG -c "seek -a -r 0" $testdir/file1 > > -echo "Seek holes and data in file2" > > -$XFS_IO_PROG -c "seek -a -r 0" $testdir/file2 > > This removed code tests that the earlier write of 64k of data into file2 > between 192k and 256k can be found by SEEK_DATA before file2 gets > sync'd to disk. Well, and it might not be able to be found if it is in the COW fork.. > And this removed code checks that the page cache contents remain stable > and correct even for a write that goes through the COW mechanism. > > I don't see why it's advantageous to remove this part of the test? Last time I send a patch to just add a sync and got the recommendation to just remove the double tests before and after the sync..
