Re: [PATCH v15 00/26] nfs/nfsd: add support for LOCALIO

[Mike Snitzer <snitzer@kernel.org>]

On Tue, Sep 10, 2024 at 04:31:23PM -0400, Anna Schumaker wrote:
> Hi Mike,
> 
> On 9/10/24 3:14 PM, Mike Snitzer wrote:
> > On Tue, Sep 10, 2024 at 12:45:11PM -0400, Mike Snitzer wrote:
> >> On Fri, Sep 06, 2024 at 04:34:18PM -0400, Mike Snitzer wrote:
> >>> On Fri, Sep 06, 2024 at 03:31:41PM -0400, Anna Schumaker wrote:
> >>>> Hi Mike,
> >>>>
> >>>> I've been running tests on localio this afternoon after finishing up going through v15 of the patches (I was most of the way through when you posted v16, so I haven't updated yet!). Cthon tests passed on all NFS versions, and xfstests passed on NFS v4.x. However, I saw this crash from xfstests with NFS v3:
> >>>>
> >>>> [ 1502.440896] run fstests generic/633 at 2024-09-06 14:04:17
> >>>> [ 1502.694356] process 'vfstest' launched '/dev/fd/4/file1' with NULL argv: empty string added
> >>>> [ 1502.699514] Oops: general protection fault, probably for non-canonical address 0x6c616e69665f6140: 0000 [#1] PREEMPT SMP NOPTI
> >>>> [ 1502.700970] CPU: 3 UID: 0 PID: 513 Comm: nfsd Not tainted 6.11.0-rc6-g0c79a48cd64d-dirty+ #42323 70d41673e6cbf8e3437eb227e0a9c3c46ed3b289
> >>>> [ 1502.702506] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022
> >>>> [ 1502.703593] RIP: 0010:nfsd_cache_lookup+0x2b3/0x840 [nfsd]
> > 
> > <snip>
> > 
> >>>>
> >>>> Please let me know if there are any other details you need about my setup to help debug this!
> >>>
> >>> Hmm, I haven't seen this issue, my runs of xfstests with LOCALIO
> >>> enabled look solid:
> >>> https://evilpiepirate.org/~testdashboard/ci?user=snitzer&branch=snitm-nfs-next&test=^fs.nfs.fstests.generic.633$
> >>>
> >>> And I know Chuck has been testing xfstests and more with the patches
> >>> applied but LOCALIO disabled in his kernel config.
> >>>
> >>> The stack seems to indicate nfsd is just handling a request (so it
> >>> isn't using LOCALIO, at least not for this op).
> >>>
> >>> Probably best if you do try v16.  v15 has issues v16 addressed.  If
> >>> you can reproduce with v16 please share your kernel .config and
> >>> xfstests config. 
> >>>
> >>> Note that I've only really tested my changes against v6.11-rc4.  But I
> >>> can rebase on v6.11-rc6 if you find v16 still fails for you.
> >>
> >> Hi Anna,
> >>
> >> Just checking back, how is LOCALIO for you at this point?  Anything
> >> you're continuing to see as an issue or need from me?
> > 
> > In case it helps, I did just rebase LOCALIO (v16 + 1 fix) ontop of
> > cel/nfsd-next (v6.11-rc6 based), and I've pushed the result here:
> > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> 
> I'm seeing the same hang on generic/525 with your latest branch.
> 
> Anna

Interesting, I just looked at ktest and it shows the regression point
to be this commit:
   nfs: implement client support for NFS_LOCALIO_PROGRAM

See:
https://evilpiepirate.org/~testdashboard/ci?user=snitzer&branch=snitm-nfs-next&test=^fs.nfs.fstests.generic.525$

I think 525 has been like this for a while, really not sure why I
ignored it... will dig deeper!

Thanks,
Mike