IJ49851: TEST SENDFILE READ FROM FILESET IS CRASHING SLES NODE

APAR status

• Closed as program error.

Error description

• There is crash observed in read_pages when called from 
  page_cache_ra_unbound on SLES with kernel version >=5.14.
  

Local fix

Problem summary

• There is crash observed in read_pages when called from 
  page_cache_ra_unbound on SLES with kernel version >=5.14.
  

Problem conclusion

• This problem is fixed in 5.1.9.2
  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:
  Newer Linux kernels try to determine if performing a readahead
  would be beneficial and trigger it if so.The problem happens
  because if readpages() aops is defined then the page are added
  onto and passed via the page_pool and not in ractl
  
  Work Around:
  None
  
  Problem trigger:
  A single large file being read sequentially from one
  node(causing a readahead to be performed on the file or by using
  a posix_fadvise call to trigger readahead forcefully) and also
  being truncated/deleted from another node at the same
  time.
  
  Symptom:
  The node crashes on SLES 15 machine. It is specific only to
  kernel version >=5.14
  
  Platforms affected:
  Linux SLES, kernel version >=5.14
  
  Functional Area affected:
  Regular file read flow in kernel version >= 5.14
  
  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