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

[Peter Schubert]

Am 18.05.2026 um 03:06 schrieb 郭玲兴:
>   Hi Rick, hi Lionel
>
> ..
>
> Regarding the "soft" mount option: understood. We will retest
> with a hard mount as well.
>
> One question is whether the observed behavior is expected.
> Even if a soft mount contributes to the problem, is it expected
> that a single RPC timeout can leave the client in a state with
> no forward progress, blocked in nfs4_drain_slot_tbl, and with
> lease renewal no longer occurring? Or would that more likely
> indicate a client-side recovery bug?
>
>
> Thanks,
> Guo Lingxing
Hi,

We performed one additional recovery test before rebooting the affected 
client.
On Windows, the affected client still existed with |TotalSessions=0|, 
but no session or open files.
We explicitly ran |Revoke-NfsMountedClient|for that client ID. The 
client record disappeared completely on the server.
More than one 120-second NFSv4.1 lease period later, Windows still had 
no client/session for that host, while the Linux NFS state-manager 
remained blocked in |nfs4_drain_slot_tbl|and did not create a new session.
This suggests that once the client reaches this state, removing all 
server-side client/session state does not trigger recovery; the Linux 
client remains stuck waiting on its old local session state.

Regards,
Peter Schubert