RHEL 6.5 panic in shrink_dcache_for_umount_subtree

Issue

• Continues kernel panic with following call traces.

BUG: Dentry ffff8804e069c600{i=0,n=XXX} still in use (1) [unmount of nfs4 0:24]
------------[ cut here ]------------
kernel BUG at fs/dcache.c:667!
invalid opcode: 0000 [#1] SMP 
[..]
Pid: 23015, comm: umount.nfs Tainted: P           ---------------    2.6.32-431.20.3.el6.x86_64 #1 IBM  BladeCenter HS22 -[7870AC1]-/68Y8163     
RIP: 0010:[<ffffffff811a3da8>]  [<ffffffff811a3da8>] shrink_dcache_for_umount_subtree+0x2a8/0x2b0
RSP: 0018:ffff8804f3a8dd98  EFLAGS: 00010296
RAX: 0000000000000058 RBX: ffff8804e069c600 RCX: 000000000000b1c3
RDX: 0000000000000000 RSI: 0000000000000046 RDI: 0000000000000246
RBP: ffff8804f3a8ddd8 R08: 0000000000000000 R09: ffffffff81645da0
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff81a843c0 R14: ffff8804e069c6d0 R15: ffff8804e069c660
FS:  00007f9388112700(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007ff608bed000 CR3: 00000004f3f7f000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process umount.nfs (pid: 23015, threadinfo ffff8804f3a8c000, task ffff8804f6054ae0)
Stack:
 ffff8804f3f92670 0000000000000282 ffff8804f3a8dde8 ffff8804f3f92400
<d> ffffffffa0395340 ffffffff81c064c0 ffff8804f3f92400 ffff8804f66afec0
<d> ffff8804f3a8ddf8 ffffffff811a3dfb ffff8804f5d62398 ffff8804f3f92400
Call Trace:
 [<ffffffff811a3dfb>] shrink_dcache_for_umount+0x4b/0x60
 [<ffffffff8118b08f>] generic_shutdown_super+0x1f/0xe0
 [<ffffffff8118b1b6>] kill_anon_super+0x16/0x60
 [<ffffffffa035f479>] nfs4_kill_super+0x39/0x90 [nfs]
 [<ffffffff8118b957>] deactivate_super+0x57/0x80
 [<ffffffff811ab2ff>] mntput_no_expire+0xbf/0x110
 [<ffffffff811aba49>] release_mounts+0xa9/0xc0
 [<ffffffff811ac0ac>] sys_umount+0x2dc/0x3a0
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
Code: 50 30 4c 8b 0a 31 d2 48 85 f6 74 04 48 8b 56 40 48 05 70 02 00 00 48 89 de 48 c7 c7 f0 6e 7c 81 48 89 04 24 31 c0 e8 4c 44 38 00 <0f> 0b eb fe 0f 0b eb fe 55 48 89 e5 53 48 83 ec 08 0f 1f 44 00 
RIP  [<ffffffff811a3da8>] shrink_dcache_for_umount_subtree+0x2a8/0x2b0
 RSP <ffff8804f3a8dd98>