Re: Re: Re: [BUG] NFSv4.1 client hang in nfs4_drain_slot_tbl under concurrent workload against Windows NFS server

[郭玲兴]

Hi Lionel,

Thanks for your response.

Here are the details you requested:

1. Windows Server version:
Microsoft Windows Server 2022
Version 10.0.20348.587

2. User accounts:
No mapping mechanism is configured.
No AD, LDAP, or passwd mapping is used.

Unmapped users are handled by the default "Everyone" account.

3. Authentication:
sec=sys (AUTH_SYS), as reported by nfsstat -m

4. CPU architecture:
- Linux clients: x86_64
- Windows server: x86_64 (64-bit OS)

5. Memory:
Each Linux client VM has 16GB RAM

---

Additional observations from two independent clients:

Client A:
age: 498061
lease_time: 120
lease_expired: 497941

Client B:
age: 69598
lease_time: 120
lease_expired: 69478

In both cases, lease_expired is approximately equal to (age - lease_time),
which suggests that the lease expired shortly after mount and has not
been successfully renewed since.

At the same time:

- Both clients hang simultaneously under concurrent workload
- Clients are stuck in nfs4_drain_slot_tbl
- No NFS RPC traffic is observed at hang time (only TCP ACK)
- nfsstat shows retrans=0
- On the Windows server side, the NFS session state is reported as "Initialized"

We are currently tracing the RPC lifecycle to identify which RPC does not complete.

Please let us know if further information would be helpful.

Thanks.


> -----原始邮件-----
> 发件人: 郭玲兴 <guolingxing@xxxxxxxxxx>
> 发送时间:2026-05-07 08:50:23 (星期四)
> 收件人: "Lionel Cons" <lionelcons1972@xxxxxxxxx>
> 抄送: linux-nfs@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> 主题: Re: Re: [BUG] NFSv4.1 client hang in nfs4_drain_slot_tbl under concurrent workload against Windows NFS server
> 
> Hi Lionel,
> 
> Thanks for your response.
> 
> Here are the details:
> 
> 1. Windows Server version:
> Microsoft Windows Server 2022
> Version 10.0.20348.587
> 
> 2. User accounts:
> No mapping mechanism is configured.
> No AD, LDAP, or passwd mapping is used.
> 
> Unmapped users are handled by the default "Everyone" account.
> 
> 3. Authentication:
> sec=sys (AUTH_SYS), as reported by nfsstat -m
> 
> 4. CPU architecture:
> - Linux clients: x86_64
> - Windows server: x86_64 (64-bit OS)
> 
> 5. Memory:
> Each Linux client VM has 16GB RAM
> 
> Thanks.
> 
> 
> > -----原始邮件-----
> > 发件人: "Lionel Cons" <lionelcons1972@xxxxxxxxx>
> > 发送时间:2026-05-06 21:28:33 (星期三)
> > 收件人: 郭玲兴 <guolingxing@xxxxxxxxxx>, linux-nfs@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> > 主题: Re: [BUG] NFSv4.1 client hang in nfs4_drain_slot_tbl under concurrent workload against Windows NFS server
> > 
> > On Wed, 6 May 2026 at 09:49, 郭玲兴 <guolingxing@xxxxxxxxxx> wrote:
> > >
> > > Hi,
> > >
> > >
> > > We encountered a reproducible NFSv4.1 client hang issue under concurrent workload.
> > >
> > >
> > > Environment:
> > > - Two independent Linux clients (VMs)
> > > - Both mount the same Windows NFS server (NFSv4.1)
> > > - Kernel version: 6.1.78
> > > - Mount options: vers=4.1,soft,proto=tcp,timeo=60,retrans=10
> > 
> > Which version of WindowsServer do you use, e.g what does the "ver"
> > command in cmd.exe output? How did you set up the user accounts, and
> > which authentication (AUTH_SYS, GSS, ...) do you use?
> > Which CPU architecture do you use? How much memory do you have on the
> > Linux NFS client?
> > 
> > Lionel
> 
> 
> 
> 
>