IJ30180: PERMISSION DENIED WHEN ACCESSING FILES

APAR status

• Closed as program error.

Error description

• Kernel v4.7 changes the inode ACLs cache
  mechanism, and GPFS (5.0.5.2+, 4.2.3.23+)
  does not adapt to the new kernel behaviors.
  Below two typical issues are observed:
  1. normal user can access one file, and
  root removes the file access privilege
  from the user by chmod command => the
  user can still access the file
  2. normal user cannot access one file, and
  root grants the file access privilege
  for the user by chmod command => the user
  cannot access the file either.
  

Local fix

• Remount the file system
  

Problem summary

• Kernel v4.7 changes the inode ACLs cache
  mechanism, and GPFS (5.0.5.2+, 4.2.3.23+)
  does not adapt to the new kernel behaviors.
  Below two typical issues are observed:
  1. normal user can access one file, and
  root removes the file access privilege
  from the user by chmod command => the
  user can still access the file
  2. normal user cannot access one file, and
  root grants the file access privilege
  for the user by chmod command => the user
  cannot access the file either.
  

Problem conclusion

• Benefits of the solution:
  Perform correct permission check when
  accessing files
  
  
  Work around:
  Remount the file system
  
  Problem trigger:
  GPFS does not adapt to the new kernel behavior
  
  Symptom:
  Unexpected Results/Behavior
  
  Platforms affected:
  All Linux with kernel v4.7+
  
  Functional Area affected:
  All Scale Users
  
  Customer Impact:
  Suggested
  

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:

  IJ30409

Fix information

• Fixed component name

  SPEC SCALE STD

• Fixed component ID

  5737F33AP

Applicable component levels