On Mon, Nov 18, 2024 at 04:31:31PM -0800, Darrick J. Wong wrote: > On Tue, Nov 19, 2024 at 12:17:56AM +0000, Filipe Manana wrote: > > On Mon, Nov 18, 2024 at 11:03 PM Darrick J. Wong <djwong@xxxxxxxxxx> wrote: > > > > > > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > > > > > This test creates a couple of patterned files on a tiny filesystem, > > > fragments the free space, clones one patterned file to the other, and > > > checks that the entire file was cloned. > > > > > > However, this test doesn't work on a 64k fsblock filesystem because > > > we've used up all the free space reservation for the rmapbt, and that > > > causes the FICLONE to error out with ENOSPC partway through. Hence we > > > need to detect the ENOSPC and _notrun the test. > > > > > > That said, it turns out that XFS has been silently dropping error codes > > > if we managed to make some progress cloning extents. That's ok if the > > > operation has REMAP_FILE_CAN_SHORTEN like copy_file_range does, but > > > FICLONE/FICLONERANGE do not permit partial results, so the dropped error > > > codes is actually an error. > > > > > > Therefore, this testcase now becomes a regression test for the patch to > > > fix that. > > > > > > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> > > > --- > > > tests/generic/562 | 10 ++++++++-- > > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > > > > > > diff --git a/tests/generic/562 b/tests/generic/562 > > > index 91360c4154a6a2..62899945003513 100755 > > > --- a/tests/generic/562 > > > +++ b/tests/generic/562 > > > @@ -15,6 +15,9 @@ _begin_fstest auto clone punch > > > . ./common/filter > > > . ./common/reflink > > > > > > +test "$FSTYP" = "xfs" && \ > > > + _fixed_by_kernel_commit XXXXXXXXXX "xfs: don't drop errno values when we fail to ficlone the entire range" > > > + > > > _require_scratch_reflink > > > _require_test_program "punch-alternating" > > > _require_xfs_io_command "fpunch" > > > @@ -48,8 +51,11 @@ while true; do > > > done > > > > > > # Now clone file bar into file foo. This is supposed to succeed and not fail > > > -# with ENOSPC for example. > > > -_reflink $SCRATCH_MNT/bar $SCRATCH_MNT/foo >>$seqres.full > > > +# with ENOSPC for example. However, XFS will sometimes run out of space. > > > +_reflink $SCRATCH_MNT/bar $SCRATCH_MNT/foo >>$seqres.full 2> $tmp.err > > > +cat $tmp.err > > > +grep -q 'No space left on device' $tmp.err && \ > > > + _notrun "ran out of space while cloning" > > > > This defeats the original purpose of the test, which was to verify > > btrfs didn't fail with -ENOSPC (or any other error). > > > > If XFS has an ENOSPC issue in some cases, and it's not fixable, why > > not make it _notrun only if it's XFS that is being tested? > > Ok, will do. In the case of xfs, we don't let you share data if the > allocation group it's in is more than about 90% full. Er... scratch that response :) It's true that XFS doesn't let you share data if the AG is more than 90% full, but this test exposed a data corruption vector in 4.20-6.12 if you did run out of space. Granted you'd only hit that if you had 64k block size and a fairly small disk (~33GB) but still, that's reason enough to keep running on XFS even if it runs out of space. ENOSPC is better than data corruption. --D > --D > > > Thanks. > > > > > > > > > > # Unmount and mount the filesystem again to verify the operation was durably > > > # persisted. > > > > > > > > >
