PM80254: Accessing NCA exported VOB causes Linux NFS server to panic

Rational ClearCase Fix Pack 10 (7.1.2.10) for 7.1.2
Rational ClearCase Fix Pack 06 (8.0.0.6) for 8.0
Rational ClearCase Fix Pack 14 (7.1.2.14) for 7.1.2
Rational ClearCase Fix Pack 11 (8.0.0.11) for 8.0
Rational ClearCase Fix Pack 12 (8.0.0.12) for 8.0
Rational ClearCase Fix Pack 15 (7.1.2.15) for 7.1.2
Rational ClearCase Fix Pack 13 (8.0.0.13) for 8.0
Rational ClearCase Fix Pack 16 (7.1.2.16) for 7.1.2
Rational ClearCase Fix Pack 17 (7.1.2.17) for 7.1.2
Rational ClearCase Fix Pack 14 (8.0.0.14) for 8.0
Rational ClearCase Fix Pack 18 (7.1.2.18) for 7.1.2
Rational ClearCase Fix Pack 15 (8.0.0.15) for 8.0
Rational ClearCase Fix Pack 19 (7.1.2.19) for 7.1.2
Rational ClearCase Fix Pack 16 (8.0.0.16) for 8.0
Rational ClearCase Fix Pack 17 (8.0.0.17) for 8.0
Rational ClearCase Fix Pack 18 (8.0.0.18) for 8.0
Rational ClearCase Fix Pack 19 (8.0.0.19) for 8.0
Rational ClearCase Fix Pack 20 (8.0.0.20) for 8.0
Rational ClearCase Fix Pack 21 (8.0.0.21) for 8.0

APAR status

• Closed as program error.

Error description

• When an IBM Rational ClearCase view/VOB combination exported
  from Red Hat Enterprise Linux 5.7 is accessed from a remote host
  the server will panic. A crash dump reveals a backtrace similar
  to the following:
  
  PANIC: 'mvfs: LOCK: recursive lock
  ffff810071cda0a0:/vobs/public/linux_vnode/rhat_x86/linux_x86_64_
  2618_rhel5/mvfsobj/mvfs_mnode.c:
  mfs_mnget :1410, locker
  /vobs/public/linux_vnode/rhat_x86/linux_x86_64_2618_rhel5/mvfsob
  j/mvfs_clnt.c:1601?0?Kernel
  panic - not syncing: VNODE panic'
  
  crash? bt
  PID: 3659   TASK: ffff810071362100  CPU: 0   COMMAND: 'nfsd'
   #0 [ffff810070e85378] crash_kexec at ffffffff800afee7
   #1 [ffff810070e85438] panic at ffffffff80093395
   #2 [ffff810070e85588] dev_queue_xmit at ffffffff8002f7ea
   #3 [ffff810070e85608] mfs_mnget at ffffffff88774f63
   #4 [ffff810070e85698] mfs_getmnode at ffffffff8875840e
   #5 [ffff810070e856e8] mfs_getvnode at ffffffff8875874c
   #6 [ffff810070e85728] mfs_bindroot at ffffffff8875c634
   #7 [ffff810070e85788] mfs_getattr at ffffffff8875fa61
   #8 [ffff810070e857d8] mvfs_linux_getattr_wrapper at
  ffffffff88795e13
   #9 [ffff810070e85808] vnode_iop_getattr at ffffffff88799b5e
  #10 [ffff810070e85848] encode_post_op_attr at ffffffff8871b8c7
  #11 [ffff810070e858e8] encode_entry at ffffffff8871c05d
  #12 [ffff810070e85bb8] nfs3svc_encode_entry_plus at
  ffffffff8871c377
  #13 [ffff810070e85bd8] mdki_linux_readdir_uiomove at
  ffffffff887a1764
  #14 [ffff810070e85c18] mfs_clnt_readdir at ffffffff887886db
  #15 [ffff810070e85ca8] mvfs_readdir_ctx at ffffffff88762f7f
  #16 [ffff810070e85cf8] vnode_fop_readdir at ffffffff887987d2
  #17 [ffff810070e85d88] vfs_readdir at ffffffff80035151
  #18 [ffff810070e85dc8] nfsd_readdir at ffffffff88713ef6
  #19 [ffff810070e85e08] nfsd3_proc_readdirplus at
  ffffffff8871b1ee
  #20 [ffff810070e85e48] nfsd_dispatch at ffffffff887101db
  #21 [ffff810070e85e78] svc_process at ffffffff8862980d
  #22 [ffff810070e85ee8] nfsd at ffffffff88710725
  #23 [ffff810070e85f48] kernel_thread at ffffffff8005dfb1
  
  Note this has also been observed on RHEL 5.8, and with ClearCase
  7.1.2.9.
  
  Steps to reproduce:
  
  1. Export a view/VOB combination for non-ClearCase access on
  RHEL 5.7 server running ClearCase 7.1.2.8
  2. Mount the export from another UNIX client and cd into the
  view/VOB
  3. Run 'ls' in the VOB root.
  
  Workaround: There is no known workaround to this defect.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Accessing NCA exported VOB causes Linux NFS server to panic
  

Problem conclusion

• A fix is available in ClearCase versions 7.1.2.10 and
  8.0.0.6
  

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

  CLEARCASE UNIX

• Fixed component ID

  5724G2901

Applicable component levels

• R712 PSN

     UP