On 03/29/2017 11:41 AM, Johannes Thumshirn wrote:
> After commit bcdde7e ("sysfs: make __sysfs_remove_dir() recursive") changed the
> removal path of kernfs to make it recursive we have to remove the SAS host
> before the SCSI host or we will see sysfs warnings like the below when
> triggering the the removal of the SAS HBA PCI device like with writing to the
> sysfs pci remove file:
>
> echo 1 > /sys/module/isci/drivers/pci:isci/<device>/remove
>
> WARNING: CPU: 2 PID: 5 at fs/sysfs/group.c:241 sysfs_remove_group+0xc3/0xd0
> sysfs group 'power' not found for kobject 'end_device-6:0'
> CPU: 16 PID: 5884 Comm: echo Not tainted 4.11.0-rc3-libsas+ #504
> Call Trace:
> dump_stack+0x85/0xc2
> __warn+0xc6/0xe0
> warn_slowpath_fmt+0x4a/0x50
> sysfs_remove_group+0xc3/0xd0
> dpm_sysfs_remove+0x52/0x60
> device_del+0x13c/0x360
> ? device_remove_file+0x14/0x20
> attribute_container_class_device_del+0x15/0x20
> transport_remove_classdev+0x4c/0x60
> ? transport_add_class_device+0x40/0x40
> attribute_container_device_trigger+0xb3/0xc0
> transport_remove_device+0x10/0x20
> sas_port_delete+0x12d/0x160 [scsi_transport_sas]
> sas_deform_port+0x1bf/0x1d0 [libsas]
> sas_unregister_ports+0x36/0x50 [libsas]
> sas_unregister_ha+0x1b/0x40 [libsas]
> isci_unregister+0x2a/0x40 [isci]
> isci_pci_remove+0x52/0xb0 [isci]
> ? __pm_runtime_resume+0x56/0x80
> pci_device_remove+0x34/0xb0
> device_release_driver_internal+0x158/0x210
> device_release_driver+0xd/0x10
> pci_stop_bus_device+0x85/0x90
> pci_stop_and_remove_bus_device_locked+0x15/0x30
> remove_store+0x59/0x70
> dev_attr_store+0x13/0x20
> sysfs_kf_write+0x40/0x50
> kernfs_fop_write+0x130/0x1b0
> __vfs_write+0x23/0x130
> ? rcu_read_lock_sched_held+0x6d/0x80
> ? rcu_sync_lockdep_assert+0x2a/0x50
> ? __sb_start_write+0xd7/0x1e0
> ? vfs_write+0x1a4/0x1f0
> vfs_write+0xc6/0x1f0
> SyS_write+0x44/0xa0
> entry_SYSCALL_64_fastpath+0x23/0xc6
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> ---
> drivers/scsi/isci/init.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
