Dear Maintainer,

* What led up to the situation?
The server is running nfs-ganesha 6.5-5 on Debian 13, and multiple Debian 13
clients are connected via NFSv4. When the number of concurrent clients
exceeds
approximately 15, the server starts producing RW LOCK mutex errors in
nfs_rpc_callback.c.
* What exactly did you do (or not do) that was effective (or
ineffective)?
I connected 15 or more NFSv4 clients to the server and performed normal file
operations (read/write) from the clients. No special configuration changes
were made beyond the default nfs-ganesha settings for multiple exports.
* What was the outcome of this action?
The server logs repeatedly show the following error:

release_cb_slot : RW LOCK : CRIT : Error 22, acquiring mutex
(&session->cb_mutex)
nfs_rpc_callback.c:1256

The server becomes unstable under load, causing failures in client file
operations.
* What outcome did you expect instead?
The server should handle multiple NFSv4 clients concurrently without
producing mutex errors or becoming unstable, maintaining normal operation
for all connected clients.

Problem Description:

When running nfs-ganesha 6.5-5 on Debian 13 (server and clients), the server
becomes unstable when more than ~15 NFSv4 clients are active. The logs
show repeated mutex acquisition errors in nfs_rpc_callback.c.

Exact error message:

release_cb_slot : RW LOCK : CRIT : Error 22, acquiring mutex
(&session->cb_mutex)
nfs_rpc_callback.c:1256

Environment:
- Server: Debian 13
- Clients: Debian 13 (~90% NFSv4.0, some NFSv4.1)
- Problem appears only under higher load (≥15 clients)

Steps to Reproduce:
1. Start nfs-ganesha 6.5-5 on Debian 13.
2. Connect ≥15 NFSv4 clients.
3. Observe repeated mutex errors and server instability.

Expected Result:
nfs-ganesha should handle multiple NFSv4 clients concurrently without
crashes
or mutex errors.

Actual Result:
Server logs show repeated "RW LOCK : Error 22" messages and becomes
unstable.