Issue

• One of our web servers crashed this morning, is there a specific module or bug that triggered the crash?
• System crashed with following panic message

Kernel BUG at /builddir/build/BUILD/openafs-1.6.5/src/libafs/MODLOAD-2.6.32-431.el6.x86_64-MP/afs_dcache.c:1091!
invalid opcode: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/online
CPU 0 
Modules linked in: nfs lockd fscache auth_rpcgss nfs_acl sunrpc autofs4 libafs(P)(U) ipv6 iptable_filter ip_tables vsock(U) ppdev vmware_balloon parport_pc parport vmci(U) i2c_piix4 i2c_core sg shpchp ext4 jbd2 mbcache sr_mod cdrom sd_mod crc_t10dif vmxnet3 pata_acpi ata_generic ata_piix mptspi mptscsih mptbase scsi_transport_spi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
Pid: 11396, comm: httpd Tainted: P           ---------------    2.6.32-504.12.2.el6.x86_64 #1 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
RIP: 0010:[<ffffffffa022bcee>]  [<ffffffffa022bcee>] afs_FreeDiscardedDCache+0x2ee/0x320 [libafs]
..
Process httpd (pid: 11396, threadinfo ffff88000b4b2000, task ffff880001d3e040)
..
Call Trace:
 [<ffffffffa022bd71>] afs_MaybeFreeDiscardedDCache+0x51/0x90 [libafs]
 [<ffffffffa022fceb>] afs_GetDCache+0x1a7b/0x22e0 [libafs]
 [<ffffffffa025b610>] afs_UFSRead+0xbf0/0x1490 [libafs]
 [<ffffffffa0203cc5>] ? afs_lhash_enter+0x55/0x1a0 [libafs]
 [<ffffffffa027bcd2>] afs_linux_fillpage+0x1f2/0x410 [libafs]
 [<ffffffffa027c22b>] afs_linux_readpage+0x1cb/0x510 [libafs]
 [<ffffffff81182038>] ? mem_cgroup_cache_charge+0xb8/0xc0
 [<ffffffff81146d5e>] ? __inc_zone_page_state+0x2e/0x30
 [<ffffffff8113b220>] ? __lru_cache_add+0x40/0x90
 [<ffffffff81125803>] filemap_fault+0x313/0x500
 [<ffffffffa0259ffb>] ? afs_open+0x23b/0x7f0 [libafs]
 [<ffffffff8114eae4>] __do_fault+0x54/0x530
 [<ffffffff8114f0b7>] handle_pte_fault+0xf7/0xb00
 [<ffffffffa024f20a>] ? afs_CopyOutAttrs+0xba/0x300 [libafs]
 [<ffffffff8152aede>] ? mutex_lock+0x1e/0x50
 [<ffffffff8114fcea>] handle_mm_fault+0x22a/0x300
 [<ffffffff8104d0d8>] __do_page_fault+0x138/0x480
 [<ffffffff81156225>] ? do_mmap_pgoff+0x335/0x380
 [<ffffffff8153003e>] do_page_fault+0x3e/0xa0
 [<ffffffff8152d3f5>] page_fault+0x25/0x30
Code: 58 00 00 00 00 e9 0b fe ff ff b9 43 04 00 00 48 c7 c2 a0 04 29 a0 48 c7 c6 50 ce 28 a0 48 c7 c7 30 05 29 a0 31 c0 e8 16 d7 2f e1 <0f> 0b eb fe b9 44 04 00 00 48 c7 c2 a0 04 29 a0 48 c7 c6 54 ce 
RIP  [<ffffffffa022bcee>] afs_FreeDiscardedDCache+0x2ee/0x320 [libafs]