Hi Matthew, On Fri, Aug 04, 2023 at 11:57:22AM -0500, Frederick Lawler wrote: > Hi Matthew, > > On Thu, Jul 27, 2023 at 01:27:56PM +0100, Matthew Wilcox wrote: > > On Thu, Jul 27, 2023 at 11:25:33AM +0100, Daniel Dao wrote: > > > On Thu, Jul 27, 2023 at 4:27 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > > > > > On Fri, Jul 21, 2023 at 11:49:04AM +0100, Daniel Dao wrote: > > > > > We do not have a reproducer yet, but we now have more debugging data > > > > > which hopefully > > > > > should help narrow this down. Details as followed: > > > > > > > > > > 1. Kernel NULL pointer deferencences in __filemap_get_folio > > > > > > > > > > This happened on a few different hosts, with a few different repeated addresses. > > > > > The addresses are 0000000000000036, 0000000000000076, > > > > > 00000000000000f6. This looks > > > > > like the xarray is corrupted and we were trying to do some work on a > > > > > sibling entry. > > > > > > > > I think I have a fix for this one. Please try the attached. > > > > > > For some reason I do not see the attached patch. Can you resend it, or > > > is it the same > > > one as in https://bugzilla.kernel.org/show_bug.cgi?id=216646#c31 ? > > > > Yes, that's the one, sorry. > > I setup a kernel with this patch to deploy out. It'll take some time to > see any results from that. I did run your multiorder.c changes with/without > the change to lib/xarray.c and that seemed to work as intended. I didn't see > any regressions across multiple seeds with our kernel config. > > Fred We deployed out the xarray lib fix to our fleet and didn't notice any more issues cropping up wrt this error among other oddities. LGTM Fred