Re: sysfs warnings since kernel 3.13-rc1: "WARNING: ... at fs/sysfs/group.c:214 sysfs_remove_group"

Frank Schäfer
2014-01-08T20:00:38Z

Am 07.01.2014 18:59, schrieb Tejun Heo:
> Hello,
>
> cc'ing Mauro and quoting whole body for him.
>
> So, ummm, the sysfs rule was that any group below a device should be
> removed before the device itself is removed; however, nothing really
> checked whether this actually was the case. We didn't care whether
> the order was reversed and if somebody forgot to remove the group
> afterwards, we just leaked it. After this commit, sysfs now whines if
> the order is reversed, so the warning.
>
> While this should probably be fixed from the v4l side, I'm really
> skeptical we're gaining anything by requiring users to explicitly
> remove groups during device removal. In most cases, this is a
> completely unnecessary task. Maybe we should just hunt down all
> remove_group calls and remove all the unnecessary ones.
>
> Thanks.
What about the USB mass storage devices ?
Is it just a coincidence that this happens with two completely different
types of USB devices ?

Regards,
Frank

> On Tue, Jan 07, 2014 at 06:44:58PM +0100, Frank Schäfer wrote:
>> Hi,
>>
>> since
>>
>> commit bcdde7e221a8750f9b62b6d0bd31b72ea4ad9309
>> Author: Tejun Heo <tj@kernel.org>
>> Date: Wed Sep 18 17:15:37 2013 -0400
>>
>> sysfs: make __sysfs_remove_dir() recursive
>>
>> Currently, sysfs directory removal is inconsistent in that it would
>> remove any files directly under it but wouldn't recurse into
>> directories. Thanks to group subdirectories, this doesn't even match
>> with kobject boundaries. sysfs is in the process of being separated
>> out so that it can be used by multiple subsystems and we want to have
>> a consistent behavior - either removal of a sysfs_dirent should remove
>> every descendant entries or none instead of something inbetween.
>>
>> This patch implements proper recursive removal in
>> __sysfs_remove_dir(). The function now walks its subtree in a
>> post-order walk to remove all descendants.
>>
>> This is a behavior change but kobject / driver layer, which currently
>> is the only consumer, has already been updated to handle duplicate
>> removal attempts, so nothing should be broken after this change.
>>
>> Signed-off-by: Tejun Heo <tj@kernel.org>
>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>
>>
>>
>> I'm getting several sysfs related warnings when closing disconnected
>> em28xx USB devices:
>>
>> [ 447.408658] ------------[ cut here ]------------
>> [ 447.408676] WARNING: CPU: 1 PID: 2489 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 447.408681] sysfs group c0a10100 not found for kobject 'vbi1'
>> [ 447.408685] Modules linked in: em28xx_rc zl10353 em28xx_dvb dvb_core
>> snd_usb_audio snd_usbmidi_lib snd_rawmidi tuner_xc2028 tvp5150 em28xx
>> videobuf2_core videobuf2_vmalloc videobuf2_memops nls_iso8859_1
>> nls_cp437 vfat fat xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit
>> ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
>> iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 447.408842] CPU: 1 PID: 2489 Comm: qv4l2 Tainted: G W
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 447.408848] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 447.408852] 00000000 00000000 e7205e38 c077985c e7205e78 e7205e68
>> c02401df c092bedc
>> [ 447.408866] e7205e94 000009b9 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 447.408876] e81a180c e7205e80 c024027e 00000009 e7205e78 c092bedc
>> e7205e94 e7205ea8
>> [ 447.408887] Call Trace:
>> [ 447.408901] [<c077985c>] dump_stack+0x48/0x69
>> [ 447.408911] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 447.408920] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.408927] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.408934] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 447.408942] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 447.408951] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 447.408959] [<c05940ac>] device_del+0x2c/0x150
>> [ 447.408965] [<c05941ec>] device_unregister+0x1c/0x60
>> [ 447.408972] [<c077644a>] ? printk+0x48/0x4a
>> [ 447.408998] [<f8b576e8>] video_unregister_device+0x38/0x40 [videodev]
>> [ 447.409092] [<f9a028a4>] em28xx_release_analog_resources+0xc4/0x100
>> [em28xx]
>> [ 447.409122] [<f9a0572b>] em28xx_release_resources+0xb/0x70 [em28xx]
>> [ 447.409132] [<f9a00c6f>] em28xx_v4l2_close+0xcf/0x150 [em28xx]
>> [ 447.409141] [<c0360ce5>] ? dput+0x15/0xe0
>> [ 447.409160] [<f8b5802e>] v4l2_release+0x2e/0x70 [videodev]
>> [ 447.409170] [<c034df2b>] __fput+0xab/0x1d0
>> [ 447.409177] [<c034e088>] ____fput+0x8/0x10
>> [ 447.409186] [<c025a709>] task_work_run+0x79/0x90
>> [ 447.409193] [<c0202141>] do_notify_resume+0x51/0x80
>> [ 447.409201] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 447.409206] ---[ end trace 1e95e1c9d6c9c835 ]---
>> [ 447.411141] em2882/3 #0: V4L2 device video1 deregistered
>> [ 447.411145] ------------[ cut here ]------------
>> [ 447.411152] WARNING: CPU: 1 PID: 2489 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 447.411154] sysfs group c0a10100 not found for kobject 'video1'
>> [ 447.411202] Modules linked in: em28xx_rc zl10353 em28xx_dvb dvb_core
>> snd_usb_audio snd_usbmidi_lib snd_rawmidi tuner_xc2028 tvp5150 em28xx
>> videobuf2_core videobuf2_vmalloc videobuf2_memops nls_iso8859_1
>> nls_cp437 vfat fat xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit
>> ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
>> iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 447.411243] CPU: 1 PID: 2489 Comm: qv4l2 Tainted: G W
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 447.411246] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 447.411253] 00000000 00000000 e7205e38 c077985c e7205e78 e7205e68
>> c02401df c092bedc
>> [ 447.411260] e7205e94 000009b9 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 447.411266] f526780c e7205e80 c024027e 00000009 e7205e78 c092bedc
>> e7205e94 e7205ea8
>> [ 447.411267] Call Trace:
>> [ 447.411273] [<c077985c>] dump_stack+0x48/0x69
>> [ 447.411278] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 447.411284] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.411289] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.411293] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 447.411298] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 447.411303] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 447.411307] [<c05940ac>] device_del+0x2c/0x150
>> [ 447.411311] [<c05941ec>] device_unregister+0x1c/0x60
>> [ 447.411315] [<c077644a>] ? printk+0x48/0x4a
>> [ 447.411334] [<f8b576e8>] video_unregister_device+0x38/0x40 [videodev]
>> [ 447.411344] [<f9a02867>] em28xx_release_analog_resources+0x87/0x100
>> [em28xx]
>> [ 447.411353] [<f9a0572b>] em28xx_release_resources+0xb/0x70 [em28xx]
>> [ 447.411360] [<f9a00c6f>] em28xx_v4l2_close+0xcf/0x150 [em28xx]
>> [ 447.411365] [<c0360ce5>] ? dput+0x15/0xe0
>> [ 447.411380] [<f8b5802e>] v4l2_release+0x2e/0x70 [videodev]
>> [ 447.411385] [<c034df2b>] __fput+0xab/0x1d0
>> [ 447.411391] [<c034e088>] ____fput+0x8/0x10
>> [ 447.411397] [<c025a709>] task_work_run+0x79/0x90
>> [ 447.411401] [<c0202141>] do_notify_resume+0x51/0x80
>> [ 447.411406] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 447.411408] ---[ end trace 1e95e1c9d6c9c836 ]---
>> [ 447.411730] ------------[ cut here ]------------
>> [ 447.411737] WARNING: CPU: 1 PID: 2489 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 447.411739] sysfs group c0a10100 not found for kobject '10-005c'
>> [ 447.411787] Modules linked in: em28xx_rc zl10353 em28xx_dvb dvb_core
>> snd_usb_audio snd_usbmidi_lib snd_rawmidi tuner_xc2028 tvp5150 em28xx
>> videobuf2_core videobuf2_vmalloc videobuf2_memops nls_iso8859_1
>> nls_cp437 vfat fat xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit
>> ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
>> iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 447.411826] CPU: 1 PID: 2489 Comm: qv4l2 Tainted: G W
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 447.411828] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 447.411836] 00000000 00000000 e7205de8 c077985c e7205e28 e7205e18
>> c02401df c092bedc
>> [ 447.411842] e7205e44 000009b9 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 447.411848] e4ccce24 e7205e30 c024027e 00000009 e7205e28 c092bedc
>> e7205e44 e7205e58
>> [ 447.411849] Call Trace:
>> [ 447.411855] [<c077985c>] dump_stack+0x48/0x69
>> [ 447.411860] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 447.411865] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.411870] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.411874] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 447.411880] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 447.411885] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 447.411889] [<c05940ac>] device_del+0x2c/0x150
>> [ 447.411895] [<c064b8f0>] ? __unregister_dummy+0x30/0x30
>> [ 447.411899] [<c05941ec>] device_unregister+0x1c/0x60
>> [ 447.411903] [<c064b60b>] i2c_unregister_device+0xb/0x10
>> [ 447.411908] [<c064b923>] __unregister_client+0x33/0x40
>> [ 447.411912] [<c05936bc>] device_for_each_child+0x2c/0x60
>> [ 447.411917] [<c064cba8>] i2c_del_adapter+0x158/0x2c0
>> [ 447.411921] [<c064b8b0>] ? __process_removed_driver+0x30/0x30
>> [ 447.411925] [<c077644a>] ? printk+0x48/0x4a
>> [ 447.411936] [<f9a042b7>] em28xx_i2c_unregister+0x17/0x30 [em28xx]
>> [ 447.411944] [<f9a0573e>] em28xx_release_resources+0x1e/0x70 [em28xx]
>> [ 447.411952] [<f9a00c6f>] em28xx_v4l2_close+0xcf/0x150 [em28xx]
>> [ 447.411956] [<c0360ce5>] ? dput+0x15/0xe0
>> [ 447.411974] [<f8b5802e>] v4l2_release+0x2e/0x70 [videodev]
>> [ 447.411979] [<c034df2b>] __fput+0xab/0x1d0
>> [ 447.411984] [<c034e088>] ____fput+0x8/0x10
>> [ 447.411990] [<c025a709>] task_work_run+0x79/0x90
>> [ 447.411994] [<c0202141>] do_notify_resume+0x51/0x80
>> [ 447.411999] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 447.412029] ---[ end trace 1e95e1c9d6c9c837 ]---
>> [ 447.412076] ------------[ cut here ]------------
>> [ 447.412083] WARNING: CPU: 1 PID: 2489 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 447.412085] sysfs group c0a10100 not found for kobject '10-0061'
>> [ 447.412130] Modules linked in: em28xx_rc zl10353 em28xx_dvb dvb_core
>> snd_usb_audio snd_usbmidi_lib snd_rawmidi tuner_xc2028 tvp5150 em28xx
>> videobuf2_core videobuf2_vmalloc videobuf2_memops nls_iso8859_1
>> nls_cp437 vfat fat xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit
>> ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
>> iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 447.412168] CPU: 1 PID: 2489 Comm: qv4l2 Tainted: G W
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 447.412170] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 447.412177] 00000000 00000000 e7205de8 c077985c e7205e28 e7205e18
>> c02401df c092bedc
>> [ 447.412184] e7205e44 000009b9 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 447.412190] e8314224 e7205e30 c024027e 00000009 e7205e28 c092bedc
>> e7205e44 e7205e58
>> [ 447.412191] Call Trace:
>> [ 447.412197] [<c077985c>] dump_stack+0x48/0x69
>> [ 447.412201] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 447.412207] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.412212] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.412216] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 447.412221] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 447.412226] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 447.412230] [<c05940ac>] device_del+0x2c/0x150
>> [ 447.412235] [<c064b8f0>] ? __unregister_dummy+0x30/0x30
>> [ 447.412238] [<c05941ec>] device_unregister+0x1c/0x60
>> [ 447.412242] [<c05933ff>] ? put_device+0xf/0x20
>> [ 447.412246] [<c059341b>] ? klist_children_put+0xb/0x10
>> [ 447.412250] [<c064b60b>] i2c_unregister_device+0xb/0x10
>> [ 447.412254] [<c064b923>] __unregister_client+0x33/0x40
>> [ 447.412258] [<c05936bc>] device_for_each_child+0x2c/0x60
>> [ 447.412263] [<c064cba8>] i2c_del_adapter+0x158/0x2c0
>> [ 447.412267] [<c064b8b0>] ? __process_removed_driver+0x30/0x30
>> [ 447.412271] [<c077644a>] ? printk+0x48/0x4a
>> [ 447.412281] [<f9a042b7>] em28xx_i2c_unregister+0x17/0x30 [em28xx]
>> [ 447.412290] [<f9a0573e>] em28xx_release_resources+0x1e/0x70 [em28xx]
>> [ 447.412297] [<f9a00c6f>] em28xx_v4l2_close+0xcf/0x150 [em28xx]
>> [ 447.412301] [<c0360ce5>] ? dput+0x15/0xe0
>> [ 447.412318] [<f8b5802e>] v4l2_release+0x2e/0x70 [videodev]
>> [ 447.412324] [<c034df2b>] __fput+0xab/0x1d0
>> [ 447.412329] [<c034e088>] ____fput+0x8/0x10
>> [ 447.412334] [<c025a709>] task_work_run+0x79/0x90
>> [ 447.412338] [<c0202141>] do_notify_resume+0x51/0x80
>> [ 447.412343] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 447.412346] ---[ end trace 1e95e1c9d6c9c838 ]---
>> [ 447.412367] xc2028 10-0061: destroying instance
>> [ 447.412391] ------------[ cut here ]------------
>> [ 447.412398] WARNING: CPU: 1 PID: 2489 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 447.412399] sysfs group c0a10100 not found for kobject 'i2c-10'
>> [ 447.412444] Modules linked in: em28xx_rc zl10353 em28xx_dvb dvb_core
>> snd_usb_audio snd_usbmidi_lib snd_rawmidi tuner_xc2028 tvp5150 em28xx
>> videobuf2_core videobuf2_vmalloc videobuf2_memops nls_iso8859_1
>> nls_cp437 vfat fat xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit
>> ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT
>> iptable_raw xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 447.412482] CPU: 1 PID: 2489 Comm: qv4l2 Tainted: G W
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 447.412484] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 447.412491] 00000000 00000000 e7205e18 c077985c e7205e58 e7205e48
>> c02401df c092bedc
>> [ 447.412498] e7205e74 000009b9 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 447.412504] e8073220 e7205e60 c024027e 00000009 e7205e58 c092bedc
>> e7205e74 e7205e88
>> [ 447.412505] Call Trace:
>> [ 447.412511] [<c077985c>] dump_stack+0x48/0x69
>> [ 447.412515] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 447.412521] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.412525] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 447.412530] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 447.412535] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 447.412540] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 447.412544] [<c05940ac>] device_del+0x2c/0x150
>> [ 447.412548] [<c05941ec>] device_unregister+0x1c/0x60
>> [ 447.412553] [<c03af3b1>] ? sysfs_remove_link+0x11/0x30
>> [ 447.412558] [<c0597c5f>] ? class_compat_remove_link+0x2f/0x50
>> [ 447.412563] [<c064cc04>] i2c_del_adapter+0x1b4/0x2c0
>> [ 447.412567] [<c064b8b0>] ? __process_removed_driver+0x30/0x30
>> [ 447.412571] [<c077644a>] ? printk+0x48/0x4a
>> [ 447.412581] [<f9a042b7>] em28xx_i2c_unregister+0x17/0x30 [em28xx]
>> [ 447.412590] [<f9a0573e>] em28xx_release_resources+0x1e/0x70 [em28xx]
>> [ 447.412597] [<f9a00c6f>] em28xx_v4l2_close+0xcf/0x150 [em28xx]
>> [ 447.412601] [<c0360ce5>] ? dput+0x15/0xe0
>> [ 447.412618] [<f8b5802e>] v4l2_release+0x2e/0x70 [videodev]
>> [ 447.412623] [<c034df2b>] __fput+0xab/0x1d0
>> [ 447.412628] [<c034e088>] ____fput+0x8/0x10
>> [ 447.412634] [<c025a709>] task_work_run+0x79/0x90
>> [ 447.412638] [<c0202141>] do_notify_resume+0x51/0x80
>> [ 447.412643] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 447.412645] ---[ end trace 1e95e1c9d6c9c839 ]---
>>
>>
>>
>> I'm also getting this error when unmounting a disconnecting a USB mass
>> storage device:
>>
>> [ 180.527140] WARNING: CPU: 0 PID: 2145 at fs/sysfs/group.c:214
>> sysfs_remove_group+0xc9/0xd0()
>> [ 180.527142] sysfs group c0a10100 not found for kobject 'target11:0:0'
>> [ 180.527144] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat
>> xt_tcpudp af_packet xt_pkttype xt_LOG xt_limit ip6t_REJECT
>> nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw ipt_REJECT iptable_raw
>> xt_CT iptable_filter ip6table_mangle nf_conntrack_netbios_ns
>> nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables
>> xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables fuse
>> snd_hda_codec_hdmi arc4 snd_hda_codec_analog rtl8187 mac80211
>> snd_hda_intel snd_hda_codec snd_hwdep snd_pcm rc_hauppauge ir_kbd_i2c
>> snd_seq tuner_simple tuner_types cfg80211 tda9887 tda8290 tuner msp3400
>> bttv v4l2_common videodev snd_timer snd_seq_device videobuf_dma_sg
>> videobuf_core usb_storage btcx_risc rc_core snd tveeprom usblp rfkill
>> forcedeth sg soundcore i2c_nforce2 shpchp eeprom_93cx6 firewire_ohci
>> firewire_core crc_itu_t ppdev k8temp sr_mod cdrom powernow_k8 kvm_amd
>> button asus_atk0110 floppy parport_pc parport pcspkr snd_page_alloc kvm
>> serio_raw autofs4 radeon ttm drm_kms_helper drm i2c_algo_bit fan thermal
>> processor thermal_sys scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc
>> scsi_dh_rdac scsi_dh ata_generic pata_amd pata_jmicron sata_nv
>> [ 180.527204] CPU: 0 PID: 2145 Comm: bash Not tainted
>> 3.13.0-rc7-0.1-desktop+ #76
>> [ 180.527206] Hardware name: System manufacturer System Product
>> Name/M2N-VM DH, BIOS ASUS M2N-VM DH ACPI BIOS Revision 1503 09/16/2010
>> [ 180.527208] 00000000 00000000 f6531bcc c077985c f6531c0c f6531bfc
>> c02401df c092bedc
>> [ 180.527213] f6531c28 00000861 c0935e02 000000d6 c03afe89 c03afe89
>> 00000000 c0a10100
>> [ 180.527217] f527761c f6531c14 c024027e 00000009 f6531c0c c092bedc
>> f6531c28 f6531c3c
>> [ 180.527221] Call Trace:
>> [ 180.527227] [<c077985c>] dump_stack+0x48/0x69
>> [ 180.527231] [<c02401df>] warn_slowpath_common+0x7f/0xa0
>> [ 180.527234] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 180.527237] [<c03afe89>] ? sysfs_remove_group+0xc9/0xd0
>> [ 180.527240] [<c024027e>] warn_slowpath_fmt+0x2e/0x30
>> [ 180.527243] [<c03afe89>] sysfs_remove_group+0xc9/0xd0
>> [ 180.527246] [<c059c32d>] dpm_sysfs_remove+0x2d/0x30
>> [ 180.527249] [<c05940ac>] device_del+0x2c/0x150
>> [ 180.527253] [<c05cb0d6>] scsi_target_reap_usercontext+0x26/0x40
>> [ 180.527257] [<c0256d44>] execute_in_process_context+0x44/0x50
>> [ 180.527260] [<c05cc6ec>] scsi_target_reap+0x8c/0xb0
>> [ 180.527263] [<c05ce372>] scsi_device_dev_release_usercontext+0x122/0x150
>> [ 180.527266] [<c0256d44>] execute_in_process_context+0x44/0x50
>> [ 180.527268] [<c05cdf13>] scsi_device_dev_release+0x13/0x20
>> [ 180.527271] [<c059362c>] device_release+0x2c/0x90
>> [ 180.527273] [<c0593633>] ? device_release+0x33/0x90
>> [ 180.527276] [<c04a8058>] kobject_cleanup+0x78/0x1b0
>> [ 180.527279] [<c04a8070>] ? kobject_cleanup+0x90/0x1b0
>> [ 180.527282] [<c04915f4>] ? part_release+0x24/0x30
>> [ 180.527286] [<c0317097>] ? free_percpu+0x77/0x100
>> [ 180.527290] [<c04a81c5>] kobject_put+0x25/0x60
>> [ 180.527293] [<c05c18b7>] ? scsi_device_put+0x47/0x50
>> [ 180.527296] [<c05933ff>] put_device+0xf/0x20
>> [ 180.527299] [<c05c189f>] scsi_device_put+0x2f/0x50
>> [ 180.527302] [<c05d138a>] scsi_disk_put+0x2a/0x40
>> [ 180.527305] [<c05d1c7f>] sd_release+0x3f/0xd0
>> [ 180.527308] [<c037e574>] __blkdev_put+0x124/0x170
>> [ 180.527311] [<c037e547>] __blkdev_put+0xf7/0x170
>> [ 180.527313] [<c037e604>] blkdev_put+0x44/0x110
>> [ 180.527318] [<c034f23c>] kill_block_super+0x3c/0x70
>> [ 180.527321] [<c034e81a>] deactivate_locked_super+0x3a/0x60
>> [ 180.527323] [<c034f4f2>] deactivate_super+0x42/0x60
>> [ 180.527326] [<c036779d>] mntput_no_expire+0xad/0x120
>> [ 180.527329] [<c0367828>] mntput+0x18/0x30
>> [ 180.527332] [<c0355085>] path_put+0x15/0x20
>> [ 180.527335] [<c0376756>] free_fs_struct+0x16/0x30
>> [ 180.527338] [<c03767df>] exit_fs+0x6f/0x80
>> [ 180.527341] [<c024203a>] do_exit+0x24a/0x980
>> [ 180.527344] [<c024d558>] ? dequeue_signal+0x78/0x180
>> [ 180.527347] [<c024285f>] do_group_exit+0x2f/0x90
>> [ 180.527350] [<c024fb39>] get_signal_to_deliver+0x239/0x5e0
>> [ 180.527354] [<c0202033>] do_signal+0x33/0xf0
>> [ 180.527357] [<c02017c5>] ? restore_sigcontext+0xe5/0x110
>> [ 180.527359] [<c0202397>] ? sys_sigreturn+0x97/0xa0
>> [ 180.527362] [<c0202155>] do_notify_resume+0x65/0x80
>> [ 180.527365] [<c077fffb>] work_notifysig+0x24/0x29
>> [ 180.527367] ---[ end trace 1e95e1c9d6c9c834 ]---
>>
>>
>> Both are 100% reproducable.
>>
>> I assume the warning means that something unexpected happened.
>> So how can these warnings be fixed ?
>>
>> Regards,
>> Frank Schäfer
>>
>>
>>