APAR status
Closed as program error.
Error description
GPFS member node os crashed unexpectedly with below error: PANIC: "BUG: unable to handle kernel NULL pointer dereference at 000000000000000c" This issue was found on GPFS 5.1.2.2 version
Local fix
Problem summary
Linux kernel 4.2 added a new field to the Linux inode data structure. When an inode is reused under heavy workload, this field might not be initialized correctly, leading to a kernel crash when accessing the symlink.
Problem conclusion
This problem is fixed in 5.1.2 PTF 7 To see all Spectrum Scale APARs and their respective fix solutions refer to page https://public.dhe.ibm.com/storage/spectrumscale/spectrum_scale_ apars.html Benefits of the solution: The solution is to initialize the field correct to avoid the crash. Work Around: It is possible to manually patch the GPl layer: Edit the file /usr/lpp/mmfs/src/gpl-linux/inode.c In function cxiSetOSNode after line: "case S_IFLNK:" insert a new line with: inodeP->i_link = NULL; Run mmbuildgpl again and restart GPFS on the node. Problem trigger: This problem is highly depended on the workload. If there is a workload creating directories, creating files underneath directories, deleting directories and also creating symlinks, there is a chance that this problem is hit. Build systems are a type of software that can exhibit this pattern. Symptom: Abend/Crash Platforms affected: ALL Linux OS environments (excluding RHEL7, since that does not include the mentioned Linux kernel change) Functional Area affected: All Scale Users Customer Impact: Critical
Temporary fix
Comments
APAR Information
APAR number
IJ41651
Reported component name
SPEC SCALE STD
Reported component ID
5737F33AP
Reported release
512
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2022-08-08
Closed date
2022-08-23
Last modified date
2022-08-23
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
SPEC SCALE STD
Fixed component ID
5737F33AP
Applicable component levels
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STXKQY"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"512","Line of Business":{"code":"LOB26","label":"Storage"}}]
Document Information
Modified date:
23 August 2022