Re: [PATCH v1 0/2] xfs: remove quota warning limits

[Brian Foster <bfoster@redhat.com>]

On Tue, Apr 26, 2022 at 07:53:47AM -0700, Darrick J. Wong wrote:
> On Tue, Apr 26, 2022 at 10:15:47AM -0400, Brian Foster wrote:
> > On Mon, Apr 25, 2022 at 07:43:31PM -0700, Darrick J. Wong wrote:
> > ...
> > > 
> > > The biggest problem right now is that the pagecache is broken in 5.18
> > > and apparently I'm the only person who can trigger this.  It's the same
> > > problem willy and I have been working on since -rc1 (where the
> > > filemap/iomap debug asserts trip on generic/068 and generic/475) that's
> > > documented on the fsdevel list.  Unfortunately, I don't have much time
> > > to work on this, because as team lead:
> > > 
> > 
> > I seem to be able to reproduce this fairly reliably with generic/068.
> > I've started a bisect if it's of any use...
> 
> Thank you!  Matthew has hinted that he suspects this is a case of the
> page cache returning the wrong folio in certain cases, but neither of us
> have been able to narrow it down to a specific commit, or even a range.
> 

So my first stab at a bisect...

git bisect start 'fs' 'mm' 'include/'
...
# good: [65722ff6181aa52c3d5b0929004af22a3a63e148] drm/amdkfd: CRIU export dmabuf handles for GTT BOs
git bisect good 65722ff6181aa52c3d5b0929004af22a3a63e148
# good: [89695196f0ba78a17453f9616355f2ca6b293402] Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
git bisect good 89695196f0ba78a17453f9616355f2ca6b293402
# bad: [52deda9551a01879b3562e7b41748e85c591f14c] Merge branch 'akpm' (patches from Andrew)
git bisect bad 52deda9551a01879b3562e7b41748e85c591f14c
# bad: [169e77764adc041b1dacba84ea90516a895d43b2] Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
git bisect bad 169e77764adc041b1dacba84ea90516a895d43b2
# first bad commit: [169e77764adc041b1dacba84ea90516a895d43b2] Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

... landed on a netdev merge commit. :/ That doesn't seem terribly
informative. I suspect either I was too aggressive with the testing or
source dir tree filtering. I've manually confirmed that the last couple
of marked merge commits are good and bad respectively, so I'll probably
try a new bisect of that range without any filtering and a bit more
deliberate testing (which will take a bit longer) and see if that yields
anything more useful.

Brian

> --D
> 
> > Brian
> > 
>