SLES 15 SP5 NFS Server is logging "nfs: inode locked twice during operation"

This document (000021718) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 15 SP5

Situation

On an NFS Server (which shares one or more of its file systems with various NFS Client hosts) there is frequent logging of this message, in /var/log/messages:

nfsd: inode locked twice during operation

There is not typically any functional failure noticed at the same time. Possibly, CPU utilization or memory usage might be somewhat effected (as you might expect from the work of extra logging), but this is unconfirmed.

Resolution

The general support period for SLES 15 SP5 has ended, and the following options are available:

1. Typically, the messages can be ignored. These are generally just an annoyance and do not correspond to an actual failure.

2. If this system has LTSS (Long Term Service Pack Support) which gives access to extended support and fixes, then updates are being prepared. Some fixes to eliminate these messages were released in the LTSS maintenance kernel release in January 2025 (kernel 5.14.21-150500-55.91). However, under certain workloads, the messages may continue. An additional fix to remove them has been created and is tentatively expected to release in mid-to-late March 2025. If desired, LTSS customers can contact SUSE Support to obtain a PTF kernel, ahead of the next kernel release.

3. The system could be upgraded to SLES 15 SP6, which does not have this issue.

Cause

The first kernel to log these unnecessary messages was SLES 15 SP5 kernel version 5.14.21-150500.55.73. Before that, they did not occur. The messages are a side effect of drawing a patch in from the linux community, which was known as:

NFSD-verify-the-opened-dentry-after-setting-a-delega.patch

it appears in the SUSE kernel change log as:

- nfsd: put the export reference in nfsd4_verify_deleg_dentry
  (git-fixes).

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.