On Tue, Mar 2, 2021 at 11:33 AM Darrick J. Wong <djwong@xxxxxxxxxx> wrote:
>
> On Tue, Mar 02, 2021 at 11:20:06AM +0800, Su Yue wrote:
> > On Tue, Mar 2, 2021 at 2:10 AM Theodore Ts'o <tytso@xxxxxxx> wrote:
> > >
> > > On Mon, Mar 01, 2021 at 09:14:40AM -0800, Darrick J. Wong wrote:
> > > > On Wed, Feb 10, 2021 at 03:58:18PM -0500, Theodore Ts'o wrote:
> > > > > This test verifies that the an unwritten extent is properly marked as
> > > > > written after writing into it.
> > > > >
> > > > > There was a hard-to-hit bug which would occasionally trigger with ext4
> > > > > for which this test was a reproducer. This has been fixed after
> > > > > moving ext4 to use iomap for Direct I/O's, although as of this
> > > > > writing, there are still some occasional failures on ext4 when block
> > > > > size < page size.
> > > >
> > > > Are there still failures?
> > >
> > > Yes. It's on Ritesh's todo list, but I don't believe it's bubbled up
> > > to the top of his list.
> > >
> > > The failure rate is substantially less than what I had been seeing
> > > with 4k block sizes before the move to iomap, and in practice it was
> > > hard to hit in production. We noticed on Google data center workloads
> > > (but even then it was impossible to reliably repro before I found this
> > > fio recipe); as far as I know no one else had reported seeing this
> > > problem.
> > >
> > > So in summary, as of this writing, on 1k and 2k block sizes, this test
> > > is still occasionally failing for ext4 (but not xfs, where it reliably
> > > passes). On 4k block sizes on x86 with ext4, this test is still
> > > failing in on 5.4 and earler kernels, unless someone has managed to
> > > backport DIO iomap support for ext4 into an enterprise linux kernel.
> > >
> > But both xfs and ext4 100% fail in v5.12-rc1 with 4k block size and 4k page
> > size on x86_64. The test itself should be okay because btrfs passes.
> > xfstests-dev version is 8cbc48b460b6 applied this patch. logs are attached.
>
> Is this generic/623? That test is new, and I've noticed it'll fail if
> you have coredumps enabled because the test tries to induce a SIGBUS.
>
Hmm.. I think the "generic/623" you mean is introduced by 011bfb01f7f9
("generic: test
mapped write after shutdown and failed writeback"). The generic/623 which
I mean is the commit 8cbc48b460b6(011bfb01f7f9~1) applied Theodore's
patch "generic: test which tries to exercise AIO/DIO into unwritten space".
--
Su
> --D
>
> >
> > # fio --version
> > fio-3.25
> >
> > #cat local.config
> > export TEST_DEV=/dev/mapper/test-1
> > export TEST_DIR=/mnt/test
> > export SCRATCH_DEV_POOL="/dev/mapper/test-[2-6]"
> > export SCRATCH_MNT=/mnt/scratch
> > export LOGWRITES_DEV="/dev/mapper/test-7"
> > export KEEP_DMESG=yes
> >
> > > - Ted
>
>
>
>
