IJ53549: KERNEL ASSERT: DATAUPDATE.HASDIRTYLOGGEDUPDATE() == 0 || DATAUPDATE.ISUPDATING() || DATAUPDATE.ISWRITEINPROGRESS() || DATAUPDATE

APAR status

• Closed as program error.

Error description

• Concurrently issuing read system calls while mmap writeback is
  running for the same region in the same file can result in the
  mentioned assert being hit. This is due to a coordination
  problem between the mmap writeback and handling of read system
  calls.
  

Local fix

• The race condition leading to this assert always exists. During
  tests it was only hit with HAWC enabled, so disabling HAWC might
  help to make this less likely to hit.
  

Problem summary

• Concurrently issuing read system calls while mmap writeback is
  running for the same region in the same file can result in the
  mentioned assert being hit. This is due to a coordination
  problem between the mmap writeback and handling of read system
  calls.
  

Problem conclusion

• This problem is fixed in 5.2.2.1
  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:
  System does not assert in this way.
  
  Work Around:
  The race condition leading to this assert always exists. During
  tests it was only hit with HAWC enabled, so disabling HAWC might
  help to make this less likely to hit.
  
  Problem trigger:
  mmap a file and write to mmap region. Issue regular read calls
  concurrently to the background mmap writeback. Enabling HAWC
  seems to increase the likelihood of hitting this problem.
  
  Symptom:
  Abend/Crash
  
  Platforms affected:
  ALL Linux OS environments
  
  Functional Area affected:
  All Scale Users
  
  Customer Impact:
  High Importance
  

Temporary fix

Comments

APAR Information

• 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