Re: [PATCH] block: Fix kernel panic occurs while creating second raid disk

2017-01-24 Thread Douglas Miller 

On 11/03/2016 12:15 AM, Sreekanth Reddy wrote:

On Tue, Nov 1, 2016 at 11:52 PM, Douglas Miller
 wrote:

On 10/24/2016 01:54 PM, Sreekanth Reddy wrote:

Observing below kernel panic while creating second raid disk
on LSI SAS3008 HBA card.

[  +0.55] [ cut here ]
[  +0.07] WARNING: CPU: 2 PID: 281 at fs/sysfs/dir.c:31
sysfs_warn_dup+0x62/0x80
[  +0.02] sysfs: cannot create duplicate filename
'/devices/virtual/bdi/8:32'
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack tun bridge
stp llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl
sb_edac edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt
ipmi_ssif mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich
mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd
grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class
nvme_core scsi_transport_sas dca
[  +0.67] CPU: 2 PID: 281 Comm: kworker/u49:5 Not tainted 4.9.0-rc2 #1
[  +0.02] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS
1.1 07/22/2015
[  +0.05] Workqueue: events_unbound async_run_entry_fn
[  +0.04] Call Trace:
[  +0.09]  [] dump_stack+0x63/0x85
[  +0.05]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.06]  [] ? kernfs_path_from_node+0x4f/0x60
[  +0.02]  [] sysfs_warn_dup+0x62/0x80
[  +0.02]  [] sysfs_create_dir_ns+0x77/0x90
[  +0.04]  [] kobject_add_internal+0x99/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.06]  [] ? device_private_init+0x23/0x70
[  +0.07]  [] ? mutex_lock+0x12/0x30
[  +0.03]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.06]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.06]  [] device_add_disk+0x168/0x480
[  +0.05]  [] ? update_autosuspend+0x51/0x60
[  +0.05]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.03]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.02] [ cut here ]
[  +0.04] WARNING: CPU: 2 PID: 281 at lib/kobject.c:240
kobject_add_internal+0x2bd/0x330
[  +0.01] kobject_add_internal failed for 8:32 with -EEXIST, don't try
to register things with the same name in the same
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack tun bridge
stp llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl
sb_edac edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt
ipmi_ssif mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich
mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd
grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class
nvme_core scsi_transport_sas dca
[  +0.43] CPU: 2 PID: 281 Comm: kworker/u49:5 Tainted: GW
4.9.0-rc2 #1
[  +0.01] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS
1.1 07/22/2015
[  +0.02] Workqueue: events_unbound async_run_entry_fn
[  +0.03] Call Trace:
[  +0.03]  [] dump_stack+0x63/0x85
[  +0.03]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.02]  [] ? sysfs_warn_dup+0x6a/0x80
[  +0.03]  [] kobject_add_internal+0x2bd/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.03]  [] ? device_private_init+0x23/0x70
[  +0.04]  [] ? mutex_lock+0x12/0x30
[  +0.02]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.03]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.04]  [] device_add_disk+0x168/0x480
[  +0.03]  [] ? update_autosuspend+0x51/0x60
[  +0.02]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.02]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.000949] BUG: unable to handle kernel
[  +0.005263] NULL pointer dereference
[  +0.002853] IP: []
sysfs_do_create_link_sd.isra.2+0x34/0xb0
[  +0.008584] PGD 0

[  +0.006115] Oops:  [#1] SMP
[  +0.004531] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack tun bridge
stp llc ebtable_filter ebtables ip6table_filter ip6_tables

Re: [PATCH] block: Fix kernel panic occurs while creating second raid disk

2016-11-02 Thread Sreekanth Reddy 
On Tue, Nov 1, 2016 at 11:52 PM, Douglas Miller
 wrote:
> On 10/24/2016 01:54 PM, Sreekanth Reddy wrote:
>>
>> Observing below kernel panic while creating second raid disk
>> on LSI SAS3008 HBA card.
>>
>> [  +0.55] [ cut here ]
>> [  +0.07] WARNING: CPU: 2 PID: 281 at fs/sysfs/dir.c:31
>> sysfs_warn_dup+0x62/0x80
>> [  +0.02] sysfs: cannot create duplicate filename
>> '/devices/virtual/bdi/8:32'
>> [  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle
>> ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack tun bridge
>> stp llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl
>> sb_edac edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt
>> ipmi_ssif mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich
>> mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd
>> grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class
>> nvme_core scsi_transport_sas dca
>> [  +0.67] CPU: 2 PID: 281 Comm: kworker/u49:5 Not tainted 4.9.0-rc2 #1
>> [  +0.02] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS
>> 1.1 07/22/2015
>> [  +0.05] Workqueue: events_unbound async_run_entry_fn
>> [  +0.04] Call Trace:
>> [  +0.09]  [] dump_stack+0x63/0x85
>> [  +0.05]  [] __warn+0xcb/0xf0
>> [  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
>> [  +0.06]  [] ? kernfs_path_from_node+0x4f/0x60
>> [  +0.02]  [] sysfs_warn_dup+0x62/0x80
>> [  +0.02]  [] sysfs_create_dir_ns+0x77/0x90
>> [  +0.04]  [] kobject_add_internal+0x99/0x330
>> [  +0.03]  [] ? vsnprintf+0x35b/0x4c0
>> [  +0.03]  [] kobject_add+0x75/0xd0
>> [  +0.06]  [] ? device_private_init+0x23/0x70
>> [  +0.07]  [] ? mutex_lock+0x12/0x30
>> [  +0.03]  [] device_add+0x119/0x670
>> [  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
>> [  +0.03]  [] device_create_vargs+0x1c/0x20
>> [  +0.06]  [] bdi_register+0x8c/0x180
>> [  +0.03]  [] bdi_register_owner+0x36/0x60
>> [  +0.06]  [] device_add_disk+0x168/0x480
>> [  +0.05]  [] ? update_autosuspend+0x51/0x60
>> [  +0.05]  [] sd_probe_async+0x110/0x1c0
>> [  +0.02]  [] async_run_entry_fn+0x39/0x140
>> [  +0.03]  [] process_one_work+0x15f/0x430
>> [  +0.02]  [] worker_thread+0x4e/0x490
>> [  +0.02]  [] ? process_one_work+0x430/0x430
>> [  +0.03]  [] kthread+0xd9/0xf0
>> [  +0.03]  [] ? kthread_park+0x60/0x60
>> [  +0.03]  [] ret_from_fork+0x25/0x30
>> [  +0.02] [ cut here ]
>> [  +0.04] WARNING: CPU: 2 PID: 281 at lib/kobject.c:240
>> kobject_add_internal+0x2bd/0x330
>> [  +0.01] kobject_add_internal failed for 8:32 with -EEXIST, don't try
>> to register things with the same name in the same
>> [  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle
>> ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack tun bridge
>> stp llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl
>> sb_edac edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt
>> ipmi_ssif mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich
>> mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd
>> grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class
>> nvme_core scsi_transport_sas dca
>> [  +0.43] CPU: 2 PID: 281 Comm: kworker/u49:5 Tainted: GW
>> 4.9.0-rc2 #1
>> [  +0.01] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS
>> 1.1 07/22/2015
>> [  +0.02] Workqueue: events_unbound async_run_entry_fn
>> [  +0.03] Call Trace:
>> [  +0.03]  [] dump_stack+0x63/0x85
>> [  +0.03]  [] __warn+0xcb/0xf0
>> [  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
>> [  +0.02]  [] ? sysfs_warn_dup+0x6a/0x80
>> [  +0.03]  [] kobject_add_internal+0x2bd/0x330
>> [  +0.03]  [] ? vsnprintf+0x35b/0x4c0
>> [  +0.03]  [] kobject_add+0x75/0xd0
>> [  +0.03]  [] ? device_private_init+0x23/0x70
>> [  +0.04]  [] ? mutex_lock+0x12/0x30
>> [  +0.02]  [] device_add+0x119/0x670
>> [  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
>> [  +0.03]  [] device_create_vargs+0x1c/0x20
>> [  +0.03]  [] bdi_register+0x8c/0x180
>> [  +0.03]  [] bdi_register_owner+0x36/0x60
>> [  +0.04]  [] device_add_disk+0x168/0x480
>> [  +0.03]  [] ? update_autosuspend+0x51/0x60
>> [  +0.02]  [] sd_probe_async+0x110/0x1c0
>> [  +0.02]  [] async_run_entry_fn+0x39/0x140
>> [  +0.02]  [] process_one_work+0x15f/0x430
>> [  +0.02]  [] worker_thread+0x4e/0x490
>> [  +0.02]  [] ? process_one_work+0x430/0x430
>> [  +0.03]  [] kthread+0xd9/0xf0
>> [  +0.03]  [] ? kthread_park+0x60/0x60
>> [  +0.03]  [] ret_from_fork+0x25/0x30
>> [  +0.000949] BUG: unable to handle kernel
>> [  +0.005263] NULL pointer dereference
>> [  +0.002853] IP: []
>> sysfs_do_create_link_sd.isra.2+0x34/0xb0
>> [  +0.008584] PGD 0
>>
>>

Re: [PATCH] block: Fix kernel panic occurs while creating second raid disk

2016-11-01 Thread Douglas Miller 

On 10/24/2016 01:54 PM, Sreekanth Reddy wrote:

Observing below kernel panic while creating second raid disk
on LSI SAS3008 HBA card.

[  +0.55] [ cut here ]
[  +0.07] WARNING: CPU: 2 PID: 281 at fs/sysfs/dir.c:31 
sysfs_warn_dup+0x62/0x80
[  +0.02] sysfs: cannot create duplicate filename 
'/devices/virtual/bdi/8:32'
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM 
iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat 
nf_conntrack tun bridge stp llc ebtable_filter ebtables 
ip6table_filter ip6_tables intel_rapl sb_edac edac_core 
x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif 
mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich 
mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl 
lockd grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore 
raid_class nvme_core scsi_transport_sas dca
[  +0.67] CPU: 2 PID: 281 Comm: kworker/u49:5 Not tainted 
4.9.0-rc2 #1
[  +0.02] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, 
BIOS 1.1 07/22/2015

[  +0.05] Workqueue: events_unbound async_run_entry_fn
[  +0.04] Call Trace:
[  +0.09]  [] dump_stack+0x63/0x85
[  +0.05]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.06]  [] ? kernfs_path_from_node+0x4f/0x60
[  +0.02]  [] sysfs_warn_dup+0x62/0x80
[  +0.02]  [] sysfs_create_dir_ns+0x77/0x90
[  +0.04]  [] kobject_add_internal+0x99/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.06]  [] ? device_private_init+0x23/0x70
[  +0.07]  [] ? mutex_lock+0x12/0x30
[  +0.03]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.06]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.06]  [] device_add_disk+0x168/0x480
[  +0.05]  [] ? update_autosuspend+0x51/0x60
[  +0.05]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.03]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.02] [ cut here ]
[  +0.04] WARNING: CPU: 2 PID: 281 at lib/kobject.c:240 
kobject_add_internal+0x2bd/0x330
[  +0.01] kobject_add_internal failed for 8:32 with -EEXIST, don't 
try to register things with the same name in the same
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM 
iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat 
nf_conntrack tun bridge stp llc ebtable_filter ebtables 
ip6table_filter ip6_tables intel_rapl sb_edac edac_core 
x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif 
mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich 
mfd_corema acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl 
lockd grace binfmt_misc sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore 
raid_class nvme_core scsi_transport_sas dca
[  +0.43] CPU: 2 PID: 281 Comm: kworker/u49:5 Tainted: G
W   4.9.0-rc2 #1
[  +0.01] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, 
BIOS 1.1 07/22/2015

[  +0.02] Workqueue: events_unbound async_run_entry_fn
[  +0.03] Call Trace:
[  +0.03]  [] dump_stack+0x63/0x85
[  +0.03]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.02]  [] ? sysfs_warn_dup+0x6a/0x80
[  +0.03]  [] kobject_add_internal+0x2bd/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.03]  [] ? device_private_init+0x23/0x70
[  +0.04]  [] ? mutex_lock+0x12/0x30
[  +0.02]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.03]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.04]  [] device_add_disk+0x168/0x480
[  +0.03]  [] ? update_autosuspend+0x51/0x60
[  +0.02]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.02]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.000949] BUG: unable to handle kernel
[  +0.005263] NULL pointer dereference
[  +0.002853] IP: [] 
sysfs_do_create_link_sd.isra.2+0x34/0xb0

[  +0.008584] PGD 0

[  +0.006115] Oops:  [#1] SMP
[  +0.004531] Modules linked in: mptctl mptbase xt_CHECKSUM 
iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat 
nf_conntrack tun bridge stp llc ebtable_filter ebtables 
ip6table_filter ip6_tables intel_rapl sb_edac edac_core 
x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif

[PATCH] block: Fix kernel panic occurs while creating second raid disk

2016-10-24 Thread Sreekanth Reddy 
Observing below kernel panic while creating second raid disk
on LSI SAS3008 HBA card.

[  +0.55] [ cut here ]
[  +0.07] WARNING: CPU: 2 PID: 281 at fs/sysfs/dir.c:31 
sysfs_warn_dup+0x62/0x80
[  +0.02] sysfs: cannot create duplicate filename 
'/devices/virtual/bdi/8:32'
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle 
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat  nf_conntrack tun bridge stp 
llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl sb_edac 
edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif 
mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich mfd_corema 
acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd grace binfmt_misc 
sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class nvme_core 
scsi_transport_sas dca
[  +0.67] CPU: 2 PID: 281 Comm: kworker/u49:5 Not tainted 4.9.0-rc2 #1
[  +0.02] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS 1.1 
07/22/2015
[  +0.05] Workqueue: events_unbound async_run_entry_fn
[  +0.04] Call Trace:
[  +0.09]  [] dump_stack+0x63/0x85
[  +0.05]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.06]  [] ? kernfs_path_from_node+0x4f/0x60
[  +0.02]  [] sysfs_warn_dup+0x62/0x80
[  +0.02]  [] sysfs_create_dir_ns+0x77/0x90
[  +0.04]  [] kobject_add_internal+0x99/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.06]  [] ? device_private_init+0x23/0x70
[  +0.07]  [] ? mutex_lock+0x12/0x30
[  +0.03]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.06]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.06]  [] device_add_disk+0x168/0x480
[  +0.05]  [] ? update_autosuspend+0x51/0x60
[  +0.05]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.03]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.02] [ cut here ]
[  +0.04] WARNING: CPU: 2 PID: 281 at lib/kobject.c:240 
kobject_add_internal+0x2bd/0x330
[  +0.01] kobject_add_internal failed for 8:32 with -EEXIST, don't try to 
register things with the same name in the same
[  +0.01] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle 
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat  nf_conntrack tun bridge stp 
llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl sb_edac 
edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif 
mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801 lpc_ich mfd_corema 
acpi_pad wmi acpi_power_meter nfsd auth_rpcgss nfs_acl lockd grace binfmt_misc 
sunrpc xfs libcrc32c ast i2c_algo_bit drm_kore raid_class nvme_core 
scsi_transport_sas dca
[  +0.43] CPU: 2 PID: 281 Comm: kworker/u49:5 Tainted: GW   
4.9.0-rc2 #1
[  +0.01] Hardware name: Supermicro SYS-2028U-TNRT+/X10DRU-i+, BIOS 1.1 
07/22/2015
[  +0.02] Workqueue: events_unbound async_run_entry_fn
[  +0.03] Call Trace:
[  +0.03]  [] dump_stack+0x63/0x85
[  +0.03]  [] __warn+0xcb/0xf0
[  +0.04]  [] warn_slowpath_fmt+0x5f/0x80
[  +0.02]  [] ? sysfs_warn_dup+0x6a/0x80
[  +0.03]  [] kobject_add_internal+0x2bd/0x330
[  +0.03]  [] ? vsnprintf+0x35b/0x4c0
[  +0.03]  [] kobject_add+0x75/0xd0
[  +0.03]  [] ? device_private_init+0x23/0x70
[  +0.04]  [] ? mutex_lock+0x12/0x30
[  +0.02]  [] device_add+0x119/0x670
[  +0.04]  [] device_create_groups_vargs+0xe0/0xf0
[  +0.03]  [] device_create_vargs+0x1c/0x20
[  +0.03]  [] bdi_register+0x8c/0x180
[  +0.03]  [] bdi_register_owner+0x36/0x60
[  +0.04]  [] device_add_disk+0x168/0x480
[  +0.03]  [] ? update_autosuspend+0x51/0x60
[  +0.02]  [] sd_probe_async+0x110/0x1c0
[  +0.02]  [] async_run_entry_fn+0x39/0x140
[  +0.02]  [] process_one_work+0x15f/0x430
[  +0.02]  [] worker_thread+0x4e/0x490
[  +0.02]  [] ? process_one_work+0x430/0x430
[  +0.03]  [] kthread+0xd9/0xf0
[  +0.03]  [] ? kthread_park+0x60/0x60
[  +0.03]  [] ret_from_fork+0x25/0x30
[  +0.000949] BUG: unable to handle kernel
[  +0.005263] NULL pointer dereference
[  +0.002853] IP: [] sysfs_do_create_link_sd.isra.2+0x34/0xb0
[  +0.008584] PGD 0

[  +0.006115] Oops:  [#1] SMP
[  +0.004531] Modules linked in: mptctl mptbase xt_CHECKSUM iptable_mangle 
ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat  nf_conntrack tun bridge stp 
llc ebtable_filter ebtables ip6table_filter ip6_tables intel_rapl sb_edac 
edac_core x86_pkg_temp_pclmul joydev ghash_clmulni_intel iTCO_wdt ipmi_ssif 
mei_me pcspkr mei iTCO_vendor_support ipmi_si i2c_i801