A vmcore occurred on a RHEL 6 cluster node that was having its GFS2 filesystems grown with the utility gfs2_grow: "BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [<ffffffffa05beb2b>] gfs2_rbm_find+0xfb/0x7a0 [gfs2]"

Issue

• A vmcore occurred on a RHEL 6 cluster node that was having its GFS2 filesystems grown with the utility gfs2_grow:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
IP: [<ffffffffa05beb2b>] gfs2_rbm_find+0xfb/0x7a0 [gfs2]
PGD 200b88c067 PUD 200ba89067 PMD 0 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:05.0/0000:11:00.0/host4/rport-4:0-5/target4:0:5/4:0:5:20/state
CPU 7 
Modules linked in: mptctl mptbase gfs2 dlm sctp libcrc32c configfs cpufreq_ondemand acpi_cpufreq freq_table mperf bonding 8021q garp stp llc ipv6 microcode iTCO_wdt iTCO_vendor_support be2net lpc_ich mfd_core hpilo hpwdt i7core_edac edac_core osst st ch power_meter acpi_ipmi ipmi_si ipmi_msghandler netxen_nic ses enclosure sg shpchp ext4 jbd2 mbcache dm_round_robin sr_mod cdrom sd_mod crc_t10dif bfa scsi_transport_fc scsi_tgt pata_acpi ata_generic ata_piix hpsa radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core dm_multipath dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]

Pid: 5980, comm: java Not tainted 2.6.32-504.el6.x86_64 #1 HP ProLiant DL580 G7
RIP: 0010:[<ffffffffa05beb2b>]  [<ffffffffa05beb2b>] gfs2_rbm_find+0xfb/0x7a0 [gfs2]
RSP: 0018:ffff880698ef1a68  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff880698ef1bb8 RCX: 0000000000000015
RDX: ffff8810108f18a8 RSI: 0000000000000000 RDI: ffff880698ef1bb8
RBP: ffff880698ef1b28 R08: 0000000000000001 R09: ffff880698ef1ce8
R10: 00016dfa2acc0c9d R11: 0000000000000001 R12: 5555555555555555
R13: ffff88101cb2d800 R14: 0000000000000080 R15: 0000000000000000
FS:  00007f5c6abfe700(0000) GS:ffff8800619c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 00000020274ab000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process java (pid: 5980, threadinfo ffff880698ef0000, task ffff88102264d540)
Stack:
 ffffffff8109eb80 ffff880698ef1a70 ffff880698ef1a70 ffff88101cb2d800
<d> 0000000000000000 0000000000000000 ffff8810108f18a8 01ff8807dea0a8cc
<d> ffff880fee0368a0 0000000000000000 ffff880698ef1bd0 00000015dea0a898
Call Trace:
 [<ffffffff8109eb80>] ? wake_bit_function+0x0/0x50
 [<ffffffffa05c0d63>] gfs2_inplace_reserve+0x5b3/0x8f0 [gfs2]
 [<ffffffffa05ac802>] gfs2_create_inode+0x462/0x1050 [gfs2]
 [<ffffffffa05aba36>] ? gfs2_glock_nq_init+0x16/0x40 [gfs2]
 [<ffffffffa05b80e3>] ? gfs2_permission+0xf3/0x210 [gfs2]
 [<ffffffffa05b7bb0>] gfs2_create+0x30/0x40 [gfs2]
 [<ffffffff8122e7bf>] ? security_inode_create+0x1f/0x30
 [<ffffffff8119d5f6>] vfs_create+0xe6/0x110
 [<ffffffff811a145e>] do_filp_open+0xa8e/0xd20
 [<ffffffff81063bf3>] ? perf_event_task_sched_out+0x33/0x70
 [<ffffffff81298eea>] ? strncpy_from_user+0x4a/0x90
 [<ffffffff811adf82>] ? alloc_fd+0x92/0x160
 [<ffffffff8118ae07>] do_sys_open+0x67/0x130
 [<ffffffff8118af10>] sys_open+0x20/0x30
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
Code: 43 08 0f 84 9c 04 00 00 83 45 ac 01 8b 45 9c 39 45 ac 0f 8d 33 04 00 00 4c 8b 6b 08 41 f6 45 10 02 75 9d 49 8b 45 00 45 8b 75 18 <4c> 03 70 28 f6 00 01 0f 84 71 06 00 00 80 7d a7 02 74 11 49 8b 
RIP  [<ffffffffa05beb2b>] gfs2_rbm_find+0xfb/0x7a0 [gfs2]
 RSP <ffff880698ef1a68>
CR2: 0000000000000028