Issue

• Stack trace:

<4>NFS: v4 server nfssrv does not accept raw uid/gids. Reenabling the idmapper.
<1>BUG: unable to handle kernel NULL pointer dereference at 000000000000000c
<1>IP: [<ffffffff8151023e>] _spin_lock+0xe/0x30
<4>PGD 200ac98067 PUD 200ac97067 PMD 0 
<4>Oops: 0002 [#1] SMP 
<4>last sysfs file: /sys/devices/virtual/block/md0/md/dev-sdb1/slot
<4>CPU 9 
<4>Modules linked in: fuse 8021q garp stp llc mptctl mptbase nfsd autofs4 nfs lockd auth_rpcgss nfs_acl sunrpc cachefiles fscache(T) ipv6 xfs exportfs hpilo raid0 hpwdt tg3 bnx2x libcrc32c mdio sg power_meter microcode serio_raw iTCO_wdt iTCO_vendor_support ioatdma dca shpchp ext4 mbcache jbd2 sd_mod crc_t10dif hpsa pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
<4>
<4>Pid: 6226, comm: kslowd002 Tainted: G           ---------------  T 2.6.32-358.2.1.el6.x86_64 #1 HP ProLiant DL380p Gen8
<4>RIP: 0010:[<ffffffff8151023e>]  [<ffffffff8151023e>] _spin_lock+0xe/0x30
<4>RSP: 0018:ffff881024d95d10  EFLAGS: 00010282
<4>RAX: 0000000000010000 RBX: 0000000000000030 RCX: ffff88101aa80a18
<4>RDX: 0000000000000000 RSI: 0000000000000005 RDI: 000000000000000c
<4>RBP: ffff881024d95d10 R08: ffffffff81abfb58 R09: efc75bfca1fe8201
<4>R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000c
<4>R13: ffff881024d95d20 R14: ffff88101aa80a08 R15: 0000000000000001
<4>FS:  0000000000000000(0000) GS:ffff881078820000(0000) knlGS:0000000000000000
<4>CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
<4>CR2: 000000000000000c CR3: 000000200de96000 CR4: 00000000000407e0
<4>DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
<4>DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
<4>Process kslowd002 (pid: 6226, threadinfo ffff881024d94000, task ffff88101a54c080)
<4>Stack:
<4> ffff881024d95dd0 ffffffffa01c3278 0000000000000000 0000000000000000
<4><d> ffff881024d95d90 ffffffff810096f0 ffff881024d95da0 ffffffff8105e759
<4><d> 00000000000005fe ffff881078834280 ffff8820293ee000 ffff881078836700
<4>Call Trace:
<4> [<ffffffffa01c3278>] fscache_invalidate_writes+0x38/0xd0 [fscache]
<4> [<ffffffff810096f0>] ? __switch_to+0xd0/0x320
<4> [<ffffffff8105e759>] ? find_busiest_queue+0x69/0x150
<4> [<ffffffff8110ddd4>] ? slow_work_enqueue+0x104/0x180
<4> [<ffffffffa01c1303>] fscache_object_slow_work_execute+0x5e3/0x9d0 [fscache]
<4> [<ffffffff81096b67>] ? bit_waitqueue+0x17/0xd0
<4> [<ffffffff8110e233>] slow_work_execute+0x233/0x310
<4> [<ffffffff8110e515>] slow_work_thread+0x205/0x360
<4> [<ffffffff81096ca0>] ? autoremove_wake_function+0x0/0x40
<4> [<ffffffff8110e310>] ? slow_work_thread+0x0/0x360
<4> [<ffffffff81096936>] kthread+0x96/0xa0
<4> [<ffffffff8100c0ca>] child_rip+0xa/0x20
<4> [<ffffffff810968a0>] ? kthread+0x0/0xa0
<4> [<ffffffff8100c0c0>] ? child_rip+0x0/0x20
<4>Code: e5 0f 1f 44 00 00 fa 66 0f 1f 44 00 00 f0 81 2f 00 00 00 01 74 05 e8 92 32 d7 ff c9 c3 55 48 89 e5 0f 1f 44 00 00 b8 00 00 01 00 <f0> 0f c1 07 0f b7 d0 c1 e8 10 39 c2 74 0e f3 90 0f b7 17 eb f5 
<1>RIP  [<ffffffff8151023e>] _spin_lock+0xe/0x30
<4> RSP <ffff881024d95d10>
<4>CR2: 000000000000000c