A kernel panic occurred on "kernel NULL pointer dereference in gfs2_inplace_reserve" on RHEL 6 or RHEL 7

Issue

A kernel panic occurred on a GFS2 filesystem:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
IP: [<ffffffffa0479631>] gfs2_inplace_reserve+0xd1/0x8a0 [gfs2]
PGD 63acbc067 PUD 63d15c067 PMD 0 
Oops: 0002 [#1] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:04.0/0000:03:00.0/0000:04:01.0/0000:06:00.1/host6/rport-6:0-13/target6:0:1/6:0:1:1/state
CPU 11 
Modules linked in: gfs2 dlm configfs autofs4 dm_round_robin scsi_dh_emc dm_multipath uinput microcode ipmi_devintf dcdbas serio_raw power_meter k10temp amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core sg ext4 jbd2 mbcache sr_mod cdrom sd_mod crc_t10dif ahci qla2xxx scsi_transport_fc scsi_tgt mpt2sas scsi_transport_sas raid_class bnx2 dm_mirror dm_region_hash dm_log dm_mod be2iscsi bnx2i cnic uio ipv6 cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio libiscsi_tcp qla4xxx iscsi_boot_sysfs libiscsi scsi_transport_iscsi [last unloaded: configfs]

Pid: 7966, comm: java Not tainted 2.6.32-431.el6.x86_64 #1 Dell Inc. PowerEdge R815/06JC9T
RIP: 0010:[<ffffffffa0479631>]  [<ffffffffa0479631>] gfs2_inplace_reserve+0xd1/0x8a0 [gfs2]
RSP: 0018:ffff88063af87ae8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff88083c4e51a8
RDX: 00000000000e0001 RSI: 00000000000d0081 RDI: ffff880638e90080
RBP: ffff88063af87ba8 R08: 0000000000000013 R09: 0000000000000004
R10: ffff88063af87c98 R11: 0000000000000000 R12: ffff8802391e4000
R13: 0000000000000000 R14: ffff8802391e4000 R15: 000000000000000f
FS:  00007f5eaac51700(0000) GS:ffff880647420000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 000000063bd04000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process java (pid: 7966, threadinfo ffff88063af86000, task ffff88063acdaae0)
Stack:
 ffff880638e90340 0000000000000000 ffff8802391e4000 ffff88043c07a0a8
<d> 000000133c07a0c0 ffff88043c07a0a8 ffff88043c07a0f8 ffff88043c07a0dc
<d> ffff88063af87b48 ffff88083c4e51a8 ffff880638e90340 ffff8802391e4000
Call Trace:
 [<ffffffffa0463583>] ? gfs2_glock_nq+0x2d3/0x3e0 [gfs2]
 [<ffffffffa046b076>] gfs2_write_begin+0x146/0x450 [gfs2]
 [<ffffffff8111ea4c>] pagecache_write_begin+0x1c/0x20
 [<ffffffff811b8409>] pipe_to_file+0x89/0x180
 [<ffffffff811b71e2>] splice_from_pipe_feed+0x72/0x120
 [<ffffffff811b8380>] ? pipe_to_file+0x0/0x180
 [<ffffffff811b82e4>] generic_file_splice_write+0xe4/0x180
 [<ffffffff811b7d7e>] do_splice_from+0x6e/0xa0
 [<ffffffff811b7dd0>] direct_splice_actor+0x20/0x30
 [<ffffffff811b80a6>] splice_direct_to_actor+0xc6/0x1c0
 [<ffffffff811b7db0>] ? direct_splice_actor+0x0/0x30
 [<ffffffff811b81ed>] do_splice_direct+0x4d/0x60
 [<ffffffff8118937c>] do_sendfile+0x18c/0x1f0
 [<ffffffff81189461>] sys_sendfile64+0x81/0xb0
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
Code: 8b 4d 88 48 8b b2 10 03 00 00 8b 51 34 48 8b 41 28 48 01 c2 48 39 d6 0f 92 c2 48 39 c6 0f 93 c0 0f b6 c0 85 d0 0f 84 92 01 00 00 <49> 89 4d 60 48 8b 55 a0 0f b7 82 ae 00 00 00 25 00 f0 00 00 3d