IJ47922: J2 FILE REMOVAL OVER NFS CAN RESULT IN A CRASH APPLIES TO AIX 7200-05

APAR status

• Closed as program error.

Error description

• In a rare circumstance a NFS  client can send two
  requests
  to it server to remove a file.  The server processes
  first
  request but does not expect the second request resulting
  in
  a crash.  Additional JFS2 code needs to be added to the
  server to avoid a crash
  The stack trace of the dump will look like the following:
  =====
  iLinkZombie
  j2_remove
  vnop_remove
  .kernel_add_gate_cstack
  rfs3_remove
  rfs_dispatch
  svc_getreq
  threadentry
  =====
  and in some cases may exclude iLinkZombie.
  

Local fix

• No local fix but this seems to occur very rarely
  

Problem summary

• The customer might see system dump during multiple delete
  requests for same file under jfs2
  

Problem conclusion

• In jfs2 remove, when number of hardlinks is zero even before
  decrementing the hard link count, instead of asserting
  log error message, as hard link zero in this scenario is not
  a severe impact as most likely two threads might be attempting
  to remove the file and anyway the file is being removed.
  

Temporary fix

Comments

• 7200-05 - use AIX APAR IJ47922
  7300-03 - use AIX APAR IJ51522
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  IJ51522 IJ51543

Fix information

• Fixed component name

  AIX V7.2

• Fixed component ID

  5765CD200

Applicable component levels