[MRG1.3] kernel crashes with Dentry still in use kernel BUG at fs/dcache.c:670 with RIP shrink_dcache_for_umount_subtree

Issue

• Kernel crashes with a message similar to RHEL5.8 bug - Dentry still in use
• Kernel crashes with the following message

[604003.294015] BUG: Dentry ffff8809ffc3f358{i=8cfd4a,n=algo} still in use (1) [unmount of autofs autofs]
[604003.294033] ------------[ cut here ]------------
[604003.294261] kernel BUG at fs/dcache.c:670!
[604003.294487] invalid opcode: 0000 [#1] PREEMPT SMP 
[604003.294720] last sysfs file: /sys/class/net/eth0/address
[604003.294950] CPU 14 
[604003.295176] Pid: 19425, comm: umount Not tainted 2.6.33.7-rt29.45.el5rt #1 /ProLiant DL380 G7
[604003.295627] RIP: 0010:[<ffffffff81105836>]  [<ffffffff81105836>] shrink_dcache_for_umount_subtree+0x11a/0x224
[604003.296087] RSP: 0018:ffff88181b6bddd8  EFLAGS: 00010296
[604003.296316] RAX: 0000000000000070 RBX: ffff8809ffc3f358 RCX: ffff8818299b0700
[604003.296765] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffffff816b77e0
[604003.297215] RBP: ffff88181b6bde08 R08: ffff88181b6bdc48 R09: 0000000000000000
[604003.297662] R10: 0000000000000000 R11: 0000000000000202 R12: ffff88182970bb28
[604003.298111] R13: ffff8809ffc3f3f0 R14: 0000000000000000 R15: ffff88181efe8000
[604003.298558] FS:  00007f43a6171760(0000) GS:ffff8800282e0000(0000) knlGS:0000000000000000
[604003.299008] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[604003.299237] CR2: 00007f43a58d4020 CR3: 0000000c24a14000 CR4: 00000000000006e0
[604003.299685] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[604003.300130] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[604003.300575] Process umount (pid: 19425, threadinfo ffff88181b6bc000, task ffff8818299b0700)
[604003.301024] Stack:
[604003.301247]  ffff88181efe8300 ffffffff810ed471 ffff88181efe8000 ffff88182970bbb0
[604003.301485] <0> ffffffffa02c6280 ffff881820df9200 ffff88181b6bde28 ffffffff81106c3f
[604003.301943] <0> ffff88181b6bde18 ffff88181efe8000 ffff88181b6bde58 ffffffff810f7462
[604003.302619] Call Trace:
[604003.302845]  [<ffffffff810ed471>] ? __cache_free+0xfb/0x1eb
[604003.303077]  [<ffffffff81106c3f>] shrink_dcache_for_umount+0x2b/0x3b
[604003.303310]  [<ffffffff810f7462>] generic_shutdown_super+0x25/0xfe
[604003.303542]  [<ffffffff810f7590>] kill_anon_super+0x16/0x54
[604003.303775]  [<ffffffffa02c262a>] autofs4_kill_sb+0x11a/0x12d [autofs4]
[604003.304007]  [<ffffffff810f7830>] deactivate_super+0x5b/0x70
[604003.304238]  [<ffffffff8110bb3b>] mntput_no_expire+0x7a/0xb5
[604003.304468]  [<ffffffff8110c12d>] sys_umount+0x2e4/0x343
[604003.304700]  [<ffffffff81002d1b>] system_call_fastpath+0x16/0x1b
[604003.304931] Code: 8b 08 48 8b 43 48 48 85 c0 74 04 48 8b 50 40 48 8d 86 00 03 00 00 48 c7 c7 18 c5 55 81 48 89 de 48 89 04 24 31 c0 e8 9e da f3 ff <0f> 0b eb fe 4c 8b 63 60 4c 39 e3 75 05 45 31 e4 eb 05 f0 41 ff 
[604003.305752] RIP  [<ffffffff81105836>] shrink_dcache_for_umount_subtree+0x11a/0x224
[604003.306206]  RSP <ffff88181b6bddd8>