On Sun, Aug 18, 2019 at 11:44:28PM +0800, Eryu Guan wrote: > On Thu, Aug 15, 2019 at 02:26:59PM -0400, Josef Bacik wrote: > > Btrfs does COW, so when we unlink the file we need to update metadata > > and write it to a new location, which we can't do because the thinp is > > full. This results in an EIO during a metadata write, which makes us > > flip read only, thus making it impossible to fstrim the fs. Just make > > it so we skip this test for btrfs. > > > > Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > --- > > tests/generic/500 | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/tests/generic/500 b/tests/generic/500 > > index 201d8b9f..5cd7126f 100755 > > --- a/tests/generic/500 > > +++ b/tests/generic/500 > > @@ -49,6 +49,12 @@ _supported_os Linux > > _require_scratch_nocheck > > _require_dm_target thin-pool > > > > +# The unlink below will result in new metadata blocks for btrfs because of CoW, > > +# and since we've filled the thinp device it'll return EIO, which will make > > +# btrfs flip read only, making it fail this test when it just won't work right > > +# for us in the first place. > > +test $FSTYP == "btrfs" && _notrun "btrfs doesn't work that way lol" > > I'm wondering if we could introduce a proper _require rule to cover this > case? e.g. require the fs doesn't allocate new blocks on unlink? or > something like that. But I'm not sure what's the proper fs feature to > require here, any suggestions? I'd be careful with this -- xfs can allocate new metadata blocks on unlink too -- changes in the free space btrees, expansion of the free inode btree, etc. For the 20 inodes in play in g/500 this won't be the case, but if you had a test that created 20,000 inodes, then that could happen. --D > Thanks, > Eryu > > > + > > # Require underlying device support discard > > _scratch_mkfs >>$seqres.full 2>&1 > > _scratch_mount > > -- > > 2.21.0 > >
