Re: small writeback fixes v2

[Boris Burkov <boris@bur.io>]

On Wed, Aug 02, 2023 at 11:35:27AM -0400, Josef Bacik wrote:
> On Wed, Aug 02, 2023 at 05:16:43PM +0200, Christoph Hellwig wrote:
> > On Wed, Aug 02, 2023 at 08:49:56AM -0400, Josef Bacik wrote:
> > > I ran this through the CI
> > 
> > Thanks a lot!
> > 
> > > [ 3461.147888] assertion failed: block_group->io_ctl.inode == NULL, in
> > > fs/btrfs/block-group.c:4256
> > 
> > Hmm, this looks so unrelated that it leaves me puzzled.  How confident
> > are you that this is a new issue based on the overall test setup?
> > 
> 
> This is the first I've seen this, so it could be new to for-next, your stuff, or
> just simply haven't hit it in the ~20ish runs I've done with this new setup.
> I'm going to go back and test these other ones with just for-next, but I wanted
> to get the results to you in case they rang a bell or you wanted to debug
> locally.

FWIW, I did not hit the crash in 1000 runs with that same config on the
btrfs_writeback_fixes branch.

> 
> > > I also got an EBUSY trying to umount $SCRATCH_MNT with generic/475 with
> > 
> > > on an ARM machine with 64kib pagesize.  Though I'm pretty sure you're not to
> > > blame for that last failure.  Thanks,
> > 
> > Yes, I've seen EBUSY in 475 quite regulary even without the changes,
> > I think I also mentioned it in reply to the other 475-related discussion
> > we had.  I tried to debug it for a while but didn't manage to get far.
> > 
> 
> Yeah it definitely reproduces on for-next, I'm debugging this right now so don't
> worry about this thing.  Thanks,
> 
> Josef