On Monday, November 25, 2013 9:19 PM, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > After commit bcdde7e221a8 (sysfs: make __sysfs_remove_dir() recursive) > Mika Westerberg sees traces analogous to the one below in Thunderbolt > hot-remove testing: > > WARNING: CPU: 0 PID: 4 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0() > sysfs group ffffffff81c6f1e0 not found for kobject 'host7' > Modules linked in: > CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.12.0+ #13 > Hardware name: /D33217CK, BIOS GKPPT10H.86A.0042.2013.0422.1439 04/22/2013 > Workqueue: kacpi_hotplug acpi_hotplug_work_fn > 0000000000000009 ffff8801002459b0 ffffffff817daab1 ffff8801002459f8 > ffff8801002459e8 ffffffff810436b8 0000000000000000 ffffffff81c6f1e0 > ffff88006d440358 ffff88006d440188 ffff88006e8b4c28 ffff880100245a48 > Call Trace: > [<ffffffff817daab1>] dump_stack+0x45/0x56 > [<ffffffff810436b8>] warn_slowpath_common+0x78/0xa0 > [<ffffffff81043727>] warn_slowpath_fmt+0x47/0x50 > [<ffffffff811ad319>] ? sysfs_get_dirent_ns+0x49/0x70 > [<ffffffff811ae526>] sysfs_remove_group+0xc6/0xd0 > [<ffffffff81432f7e>] dpm_sysfs_remove+0x3e/0x50 > [<ffffffff8142a0d0>] device_del+0x40/0x1b0 > [<ffffffff8142a24d>] device_unregister+0xd/0x20 > [<ffffffff8144131a>] scsi_remove_host+0xba/0x110 > [<ffffffff8145f526>] ata_host_detach+0xc6/0x100 > [<ffffffff8145f578>] ata_pci_remove_one+0x18/0x20 > [<ffffffff812e8f48>] pci_device_remove+0x28/0x60 > [<ffffffff8142d854>] __device_release_driver+0x64/0xd0 > [<ffffffff8142d8de>] device_release_driver+0x1e/0x30 > [<ffffffff8142d257>] bus_remove_device+0xf7/0x140 > [<ffffffff8142a1b1>] device_del+0x121/0x1b0 > [<ffffffff812e43d4>] pci_stop_bus_device+0x94/0xa0 > [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 > [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 > [<ffffffff812e44dd>] pci_stop_and_remove_bus_device+0xd/0x20 > [<ffffffff812fc743>] trim_stale_devices+0x73/0xe0 > [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 > [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 > [<ffffffff812fcb6e>] acpiphp_check_bridge+0x7e/0xd0 > [<ffffffff812fd90d>] hotplug_event+0xcd/0x160 > [<ffffffff812fd9c5>] hotplug_event_work+0x25/0x60 > [<ffffffff81316749>] acpi_hotplug_work_fn+0x17/0x22 > [<ffffffff8105cf3a>] process_one_work+0x17a/0x430 > [<ffffffff8105db29>] worker_thread+0x119/0x390 > [<ffffffff8105da10>] ? manage_workers.isra.25+0x2a0/0x2a0 > [<ffffffff81063a5d>] kthread+0xcd/0xf0 > [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 > [<ffffffff817eb33c>] ret_from_fork+0x7c/0xb0 > [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 > > The source of this problem is that SCSI hosts are removed from > ATA ports after calling ata_tport_delete() which removes the > port's sysfs directory, among other things. Now, after commit > bcdde7e221a8, the sysfs directory is removed along with all of > its subdirectories that include the SCSI host's sysfs directory > and its subdirectories at this point. Consequently, when > device_del() is finally called for any child device of the SCSI > host and tries to remove its "power" group (which is already > gone then), it triggers the above warning. > > To make the warnings go away, change the removal ordering in > ata_port_detach() so that the SCSI host is removed from the > port before ata_tport_delete() is called. > > References: https://bugzilla.kernel.org/show_bug.cgi?id=65281 > Reported-and-tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Tested-by: Jingoo Han <jg1.han@xxxxxxxxxxx> I tested this patch on Exynos platform with PCI-SATA card. I checked that the kernel panic is resolved. Thank you. Best regards, Jingoo Han > --- > > Hi, > > This along with https://patchwork.kernel.org/patch/3226081/ makes > all of the warnings observed by Mika go away without the patch at > https://patchwork.kernel.org/patch/3201841/ applied. > > Thanks, > Rafael > > --- > drivers/ata/libata-core.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > Index: linux-pm/drivers/ata/libata-core.c > =================================================================== > --- linux-pm.orig/drivers/ata/libata-core.c > +++ linux-pm/drivers/ata/libata-core.c > @@ -6304,10 +6304,9 @@ static void ata_port_detach(struct ata_p > for (i = 0; i < SATA_PMP_MAX_PORTS; i++) > ata_tlink_delete(&ap->pmp_link[i]); > } > - ata_tport_delete(ap); > - > /* remove the associated SCSI host */ > scsi_remove_host(ap->scsi_host); > + ata_tport_delete(ap); > } > > /** > > -- -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
