Andrew Morton wrote: > On Tue, 29 Nov 2022 19:59:14 -0800 Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > [ add Andrew ] > > > > Shiyang Ruan wrote: > > > Many testcases failed in dax+reflink mode with warning message in dmesg. > > > This also effects dax+noreflink mode if we run the test after a > > > dax+reflink test. So, the most urgent thing is solving the warning > > > messages. > > > > > > Patch 1 fixes some mistakes and adds handling of CoW cases not > > > previously considered (srcmap is HOLE or UNWRITTEN). > > > Patch 2 adds the implementation of unshare for fsdax. > > > > > > With these fixes, most warning messages in dax_associate_entry() are > > > gone. But honestly, generic/388 will randomly failed with the warning. > > > The case shutdown the xfs when fsstress is running, and do it for many > > > times. I think the reason is that dax pages in use are not able to be > > > invalidated in time when fs is shutdown. The next time dax page to be > > > associated, it still remains the mapping value set last time. I'll keep > > > on solving it. > > > > > > The warning message in dax_writeback_one() can also be fixed because of > > > the dax unshare. > > > > Thank you for digging in on this, I had been pinned down on CXL tasks > > and worried that we would need to mark FS_DAX broken for a cycle, so > > this is timely. > > > > My only concern is that these patches look to have significant collisions with > > the fsdax page reference counting reworks pending in linux-next. Although, > > those are still sitting in mm-unstable: > > > > http://lore.kernel.org/r/20221108162059.2ee440d5244657c4f16bdca0@xxxxxxxxxxxxxxxxxxxx > > As far as I know, Dan's "Fix the DAX-gup mistake" series is somewhat > stuck. Jan pointed out: > > https://lore.kernel.org/all/20221109113849.p7pwob533ijgrytu@quack3/T/#u > > or have Jason's issues since been addressed? No, they have not. I do think the current series is a step forward, but given the urgency remains low for the time being (CXL hotplug use case further out, no known collisions with ongoing folio work, and no MEMORY_DEVICE_PRIVATE users looking to build any conversions on top for 6.2) I am ok to circle back for 6.3 for that follow on work to be integrated. > > My preference would be to move ahead with both in which case I can help > > rebase these fixes on top. In that scenario everything would go through > > Andrew. > > > > However, if we are getting too late in the cycle for that path I think > > these dax-fixes take precedence, and one more cycle to let the page > > reference count reworks sit is ok. > > That sounds a decent approach. So we go with this series ("fsdax,xfs: > fix warning messages") and aim at 6.3-rc1 with "Fix the DAX-gup > mistake"? > Yeah, that's the path of least hassle.
