Re: NFSv4 crash of CURRENT

Hi,

Forgot to mention I’m on 13-stable. The fix that is causing the crash with automounted NFS is:

commit cc5cda1dbaa907ce52074f47264cc45b5a7d6c8b
Author: Konstantin Belousov <kib@FreeBSD.org>
Date:   Tue Jan 2 00:22:44 2024 +0200

    nfsclient: limit situations when we do unlocked read-ahead by nfsiod
    
    (cherry picked from commit 70dc6b2ce314a0f32755005ad02802fca7ed186e)

When I remove the fix, the problem is gone. Add it back and the crash happens.

Peter

> On 15 Jan 2024, at 09:31, Peter Blok <pblok@bsd4all.org> wrote:
> 
> Hi,
> 
> I do have a crash on a NFS client with stable of today (4c4633fdffbe8e4b6d328c2bc9bb3edacc9ab50a). It is also autofs related. Maybe it is the same problem.
> 
> I have ports automounted on /am/ports. When I do cd /am/ports/sys and type tab to autocomplete it crashes with the below stack trace. If I plainly mount ports on /usr/ports and do the same everything works. I am using NFSv3
> 
> Peter
> 
> 
> 
> 
> Fatal trap 12: page fault while in kernel mode
> cpuid = 2; apic id = 04
> fault virtual address	= 0x89
> fault code		= supervisor read data, page not present
> instruction pointer	= 0x20:0xffffffff809645d4
> stack pointer	        = 0x28:0xfffffe00acadb830
> frame pointer	        = 0x28:0xfffffe00acadb830
> code segment		= base 0x0, limit 0xfffff, type 0x1b
> 			= DPL 0, pres 1, long 1, def32 0, gran 1
> processor eflags	= interrupt enabled, resume, IOPL = 0
> current process		= 6869 (csh)
> trap number		= 12
> panic: page fault
> cpuid = 2
> time = 1705306940
> KDB: stack backtrace:
> #0 0xffffffff806232f5 at kdb_backtrace+0x65
> #1 0xffffffff805d7a02 at vpanic+0x152
> #2 0xffffffff805d78a3 at panic+0x43
> #3 0xffffffff809d58ad at trap_fatal+0x38d
> #4 0xffffffff809d58ff at trap_pfault+0x4f
> #5 0xffffffff809af048 at calltrap+0x8
> #6 0xffffffff804c7a7e at ncl_bioread+0xb7e
> #7 0xffffffff804b9d90 at nfs_readdir+0x1f0
> #8 0xffffffff8069c61a at vop_sigdefer+0x2a
> #9 0xffffffff809f8ae0 at VOP_READDIR_APV+0x20
> #10 0xffffffff81ce75de at autofs_readdir+0x2ce
> #11 0xffffffff809f8ae0 at VOP_READDIR_APV+0x20
> #12 0xffffffff806c3002 at kern_getdirentries+0x222
> #13 0xffffffff806c33a9 at sys_getdirentries+0x29
> #14 0xffffffff809d6180 at amd64_syscall+0x110
> #15 0xffffffff809af95b at fast_syscall_common+0xf8
> 
> 
> 
>> On 15 Jan 2024, at 06:46, FreeBSD User <freebsd@walstatt-de.de <mailto:freebsd@walstatt-de.de>> wrote:
>> 
>> Am Sun, 14 Jan 2024 20:34:12 -0800
>> Cy Schubert <Cy.Schubert@cschubert.com <mailto:Cy.Schubert@cschubert.com>> schrieb:
>> 
>>> In message <CAM5tNy5aat8vUn2fsX9jV=D9yGZdnO20Q0Ea7qtszx+zSES2bw@mail.gmail.c <mailto:CAM5tNy5aat8vUn2fsX9jV=D9yGZdnO20Q0Ea7qtszx+zSES2bw@mail.gmail.c>
>>> om>  
>>> , Rick Macklem writes:
>>>> On Sat, Jan 13, 2024 at 12:39=E2=80=AFPM Ronald Klop <ronald-lists@klop.ws <mailto:ronald-lists@klop.ws>>=
>>>> wrote:  
>>>>> 
>>>>> 
>>>>> Van: FreeBSD User <freebsd@walstatt-de.de <mailto:freebsd@walstatt-de.de>>
>>>>> Datum: 13 januari 2024 19:34
>>>>> Aan: FreeBSD CURRENT <freebsd-current@freebsd.org <mailto:freebsd-current@freebsd.org>>
>>>>> Onderwerp: NFSv4 crash of CURRENT
>>>>> 
>>>>> Hello,
>>>>> 
>>>>> running CURRENT client (FreeBSD 15.0-CURRENT #4 main-n267556-69748e62e82a=  
>>>> : Sat Jan 13 18:08:32  
>>>>> CET 2024 amd64). One NFSv4 server is same OS revision as the mentioned cl=  
>>>> ient, other is FreeBSD  
>>>>> 13.2-RELEASE-p8. Both offer NFSv4 filesystems, non-kerberized.
>>>>> 
>>>>> I can crash the client reproducable by accessing the one or other NFSv4 F=  
>>>> S (a simple ls -la).  
>>>>> The NFSv4 FS is backed by ZFS (if this matters). I do not have physicla a=  
>>>> ccess to the client  
>>>>> host, luckily the box recovers.  
>>>> Did you rebuild both the nfscommon and nfscl modules from the same sources?
>>>> I did a commit to main that changes the interface between these two
>>>> modules and did bump the
>>>> __FreeBSD_version to 1500010, which should cause both to be rebuilt.
>>>> (If you have "options NFSCL" in your kernel config, both should have
>>>> been rebuilt as a part of
>>>> the kernel build.)
>>>> 
>>> 
>>> Is anyone by chance seeing autofs in the backtrace too?
>>> 
>>> 
>> 
>> Hello Cy Shubert,
>> 
>> I forgot to mention that those crashes occur with autofs mounted filesystems. Good question,
>> by the way, I will check whether crashes also happen when mounting the tradidional way.
>> 
>> Kind regards,
>> 
>> oh
>> 
>> -- 
>> O. Hartmann
>