On Thu, Mar 05, 2015 at 09:09:00AM +1100, Dave Chinner wrote: > On Wed, Mar 04, 2015 at 10:54:21AM -0500, J. Bruce Fields wrote: > > On Tue, Mar 03, 2015 at 09:08:26PM -0500, J. Bruce Fields wrote: > > > On Wed, Mar 04, 2015 at 09:44:56AM +1100, Dave Chinner wrote: > > > > On Tue, Mar 03, 2015 at 05:10:33PM -0500, J. Bruce Fields wrote: > > > > > I'm getting mysterious crashes on a server exporting an xfs filesystem. > > > > > > > > > > Strangely, I've reproduced this on > > > > > > > > > > 93aaa830fc17 "Merge tag 'xfs-pnfs-for-linus-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs > > > > > > > > > > but haven't yet managed to reproduce on either of its parents > > > > > (24a52e412ef2 or 781355c6e5ae). That might just be chance, I'll try > > > > > again. > > > > > > > > I think you'll find that the bug is only triggered after that XFS > > > > merge because it's what enabled block layout support in the server, > > > > i.e. nfsd4_setup_layout_type() is now setting the export type to > > > > LAYOUT_BLOCK_VOLUME because XFS has added the necessary functions to > > > > it's export ops. > > > > > > Doh--after all the discussion I didn't actually pay attention to what > > > happened in the end. OK, I see, you're right, it's all more-or-less > > > dead code till that merge. > > > > > > Christoph's code was passing all my tests before that, so maybe we > > > broke something in the merge process. > > > > > > Alternatively, it could be because I've added more tests--I'll rerun my > > > current tests on his original branch.... > > > > The below is on Christoph's pnfsd-for-3.20-4 (at cd4b02e). Doesn't look > > very informative. I'm running xfstests over NFSv4.1 with client and > > server running the same kernel, the filesystem in question is xfs, but > > isn't otherwise available to the client (so the client shouldn't be > > doing pnfs). > > > > --b. > > > > BUG: unable to handle kernel paging request at 00000000757d4900 > > IP: [<ffffffff810b59af>] cpuacct_charge+0x5f/0xa0 > > PGD 0 > > Thread overran stack, or stack corrupted > > Hmmmm. That is not at all informative, especially as it's only > dumped the interrupt stack and not the stack or the task that it > has detected as overrun or corrupted. > > Can you turn on all the stack overrun debug options? Maybe even > turn on the stack tracer to get an idea of whether we are recursing > deeply somewhere we shouldn't be? Digging around under "Kernel hacking".... I already have DEBUG_STACK_USAGE, DEBUG_STACKOVERFLOW, and STACK_TRACER, and I can try turning on the latter. (Will I be able to get information out of it before the panic?) I guess I'll also try SCHED_STACK_END_CHECK. Anything else I'm missing? --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
