RHEL5: Panic while unmounting vxfs filesystem due to busy dentry

Issue

System panicked while unmounting a vxfs filesystem with this message:

BUG: Dentry ffff8110aa4f9b70{i=29ce,n=caspdied32.binfile.858.ctb_1} still in use (1) [unmount of vxfs VxVM16000]
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Kernel BUG at fs/dcache.c:612
invalid opcode: 0000 [1] SMP 
last sysfs file: /class/fc_host/host4/statistics/invalid_crc_count
CPU 7 
Modules linked in: cdr(PU) cvblk(PU) raid456 xor raid1 raid0 linear ide_cd loop vfat msdos fat nfs nfs_acl mptctl mptbase vxodm(PFU) vxfen(PU) gab(PU) llt(PU) autofs4 dmpCLARiiON(PU) dmpap(PU) vxspec(PFU) vxio(PFU) vxdmp(PU) lockd sunrpc bonding ip6t_REJECT xt_tcpudp ip6table_filter ip6_tables x_tables be2iscsi ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp bnx2i cnic ipv6 xfrm_nalgo crypto_api uio cxgb3i libcxgbi cxgb3 libiscsi_tcp libiscsi2 scsi_transport_iscsi2 scsi_transport_iscsi vxportal(PFU) fdd(PFU) vxfs(PU) exportfs dm_multipath scsi_dh video backlight sbs power_meter hwmon i2c_ec i2c_core dell_wmi wmi button battery asus_acpi acpi_memhotplug ac parport_pc lp parport joydev sr_mod cdrom sg tpm_tis tpm serio_raw i7core_edac edac_mc tpm_bios netxen_nic hpilo pcspkr shpchp bnx2 8021q dm_raid45 dm_message dm_region_hash dm_mem_cache dm_snapshot dm_zero dm_mirror dm_log dm_mod lpfc scsi_transport_fc ata_piix libata cciss sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
Pid: 855, comm: caspdied32 Tainted: PF    --------------------    2.6.18-348.12.1.el5 #1
RIP: 0010:[<ffffffff800f0b37>]  [<ffffffff800f0b37>] shrink_dcache_for_umount_subtree+0x177/0x222
RSP: 0018:ffff811053db3ec8  EFLAGS: 00010282
RAX: 0000000000000074 RBX: ffff8110aa4f9b70 RCX: ffffffff80326028
RDX: ffffffff80326028 RSI: 0000000000000000 RDI: ffffffff80326020
RBP: ffff81130f710ee0 R08: ffffffff80326028 R09: 0000000000000032
R10: ffff811053db3b68 R11: 0000000000000080 R12: ffff8110aa4f9bd0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff81181ff22ac0(0063) knlGS:00000000f7eba6c0
CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
CR2: 00000000f7f823f3 CR3: 0000000b402f8000 CR4: 00000000000006a0
Process caspdied32 (pid: 855, threadinfo ffff811053db2000, task ffff811819a66080)
Stack:  ffff8117ea728620 ffff811053db2000 ffff8117ea728400 ffffffff88686dc0
 0000000000000000 ffffffff800f1053 ffff8117ea728400 ffffffff800e8393
 ffff8117ea728400 ffffffff88686d40 0000000000000000 ffffffff800e8572
Call Trace:
 [<ffffffff800f1053>] shrink_dcache_for_umount+0x37/0x45
 [<ffffffff800e8393>] generic_shutdown_super+0x1b/0xfb
 [<ffffffff800e8572>] deactivate_super+0x6a/0x82
 [<ffffffff80024203>] filp_close+0x5c/0x64
 [<ffffffff8001e5fb>] sys_close+0x88/0xbd
 [<ffffffff800614b5>] sysenter_do_call+0x1e/0x76


Code: 0f 0b 68 9e 3c 2c 80 c2 64 02 5f 41 58 eb fe 48 8b 6b 28 48 
RIP  [<ffffffff800f0b37>] shrink_dcache_for_umount_subtree+0x177/0x222
 RSP <ffff811053db3ec8>