Re: [lkp-robot] [scsi, block] 0dba1314d4: WARNING:at_fs/sysfs/dir.c:#sysfs_warn_dup
From: James Bottomley
Date: Sat Feb 04 2017 - 16:04:45 EST
On Sat, 2017-02-04 at 12:37 -0800, Dan Williams wrote:
> On Sat, Feb 4, 2017 at 12:36 PM, Dan Williams <
> dan.j.williams@xxxxxxxxx> wrote:
> > On Fri, Feb 3, 2017 at 11:09 PM, kernel test robot
> > <xiaolong.ye@xxxxxxxxx> wrote:
> > >
> > > FYI, we noticed the following commit:
> > >
> > > commit: 0dba1314d4f81115dce711292ec7981d17231064 ("scsi, block:
> > > fix duplicate bdi name registration crashes")
> > > https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block
> > > .git for-4.11/next
> > >
> > > in testcase: boot
> > >
> > > on test machine: qemu-system-i386 -enable-kvm -cpu
> > > Haswell,+smep,+smap -m 360M
> > >
> > > caused below changes (please refer to attached dmesg/kmsg for
> > > entire log/backtrace):
> > >
> > >
> > > +----------------------------------------------+------------+----
> > > --------+
> > > > | efa7c9f97e |
> > > > 0dba1314d4 |
> > > +----------------------------------------------+------------+----
> > > --------+
> > > > boot_successes | 0 | 0
> > > > |
> > > > boot_failures | 6 | 6
> > > > |
> > > > WARNING:at_include/linux/kref.h:#kobject_get | 6 | 6
> > > > |
> > > > BUG:workqueue_lockup-pool | 2 |
> > > > |
> > > > WARNING:at_fs/sysfs/dir.c:#sysfs_warn_dup | 0 | 6
> > > > |
> > > +----------------------------------------------+------------+----
> > > --------+
> > >
> > >
> > >
> > > [ 8.820258] ------------[ cut here ]------------
> > > [ 8.821188] WARNING: CPU: 0 PID: 1 at fs/sysfs/dir.c:31
> > > sysfs_warn_dup+0x58/0x70
> > > [ 8.822994] sysfs: cannot create duplicate filename
> > > '/class/scsi_disk/0:0:0:0'
> > > [ 8.824567] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W
> > > 4.10.0-rc5-00097-g0dba131 #1
> > > [ 8.826275] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > > 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
> > > [ 8.828156] Call Trace:
> > > [ 8.828851] dump_stack+0x79/0xa4
> > > [ 8.829628] __warn+0xd2/0xf0
> > > [ 8.830372] ? sysfs_warn_dup+0x58/0x70
> > > [ 8.831211] warn_slowpath_fmt+0x36/0x40
> > > [ 8.832054] sysfs_warn_dup+0x58/0x70
> > > [ 8.832865] sysfs_do_create_link_sd+0x9e/0xb0
> > > [ 8.833844] sysfs_create_link+0x20/0x40
> > > [ 8.834714] device_add+0x218/0x610
> > > [ 8.835511] ? kvasprintf_const+0x49/0x60
> > > [ 8.836352] ? kobject_set_name_vargs+0x62/0x80
> > > [ 8.837253] sd_probe+0x31a/0x390
> > > [ 8.838027] ? _raw_spin_unlock+0x1d/0x30
> > > [ 8.838884] driver_probe_device+0x190/0x4a0
> > > [ 8.839751] __device_attach_driver+0x6f/0x100
> > > [ 8.840736] ? klist_next+0x6e/0x100
> > > [ 8.841538] ? __driver_attach+0xf0/0xf0
> > > [ 8.842383] bus_for_each_drv+0x47/0x80
> > > [ 8.843226] __device_attach+0xa8/0x120
> > > [ 8.844062] ? __driver_attach+0xf0/0xf0
> > > [ 8.844902] device_initial_probe+0xd/0x10
> > > [ 8.845754] bus_probe_device+0x77/0x80
> > > [ 8.846593] device_add+0x320/0x610
> > > [ 8.847387] scsi_sysfs_add_sdev+0x85/0x2b0
> > > [ 8.848246] ? scsi_attach_vpd+0x1f9/0x210
> > > [ 8.849103] scsi_probe_and_add_lun+0xd44/0xe70
> > > [ 8.850021] __scsi_scan_target+0xd8/0x690
> > > [ 8.850918] ? __pm_runtime_resume+0x37/0x80
> > > [ 8.852124] scsi_scan_channel+0x8f/0xb0
> > > [ 8.852977] scsi_scan_host_selected+0x100/0x180
> > > [ 8.853885] do_scsi_scan_host+0x8a/0x90
> > > [ 8.854733] scsi_scan_host+0x15a/0x1a0
> > > [ 8.855562] sdebug_driver_probe+0x14f/0x3d0
> > > [ 8.856435] ? _raw_spin_unlock+0x1d/0x30
> > > [ 8.857270] ? devices_kset_move_last+0x71/0xc0
> > > [ 8.858170] ? sysfs_create_link+0x20/0x40
> > > [ 8.859057] driver_probe_device+0xd4/0x4a0
> > > [ 8.859924] __device_attach_driver+0x6f/0x100
> > > [ 8.860814] ? klist_next+0x6e/0x100
> > > [ 8.861619] ? __driver_attach+0xf0/0xf0
> > > [ 8.862470] bus_for_each_drv+0x47/0x80
> > > [ 8.863298] __device_attach+0xa8/0x120
> > > [ 8.864131] ? __driver_attach+0xf0/0xf0
> > > [ 8.864975] device_initial_probe+0xd/0x10
> > > [ 8.865831] bus_probe_device+0x77/0x80
> > > [ 8.866704] device_add+0x320/0x610
> > > [ 8.867497] ? pm_runtime_init+0xea/0xf0
> > > [ 8.868326] device_register+0x12/0x20
> > > [ 8.869146] sdebug_add_adapter+0xda/0x1e0
> > > [ 8.870002] ? driver_register+0x83/0xe0
> > > [ 8.870847] scsi_debug_init+0x5a0/0x6eb
> > > [ 8.871686] ? kobject_uevent+0xa/0x10
> > > [ 8.872507] ? driver_register+0x83/0xe0
> > > [ 8.873336] ? scsi_register_driver+0xf/0x20
> > > [ 8.874218] ? init_ch_module+0x9d/0x9d
> > > [ 8.875088] do_one_initcall+0x7b/0x132
> > > [ 8.875918] ? kernel_init_freeable+0xe7/0x188
> > > [ 8.876807] kernel_init_freeable+0x10a/0x188
> > > [ 8.877690] ? rest_init+0xb0/0xb0
> > > [ 8.878482] kernel_init+0xb/0x100
> > > [ 8.879262] ? schedule_tail+0xc/0x70
> > > [ 8.880076] ? rest_init+0xb0/0xb0
> > > [ 8.880861] ret_from_fork+0x21/0x2c
> > > [ 8.881688] ---[ end trace 62a20110376b9cdf ]---
> > >
> > >
> > > To reproduce:
> > >
> > > git clone
> > > git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
> > > cd lkp-tests
> > > bin/lkp qemu -k <bzImage> job-script # job-script is
> > > attached in this email
> >
> > These reproduction steps don't work for me. I also notice that
> > 0day is picking up on a later error, the real error is that we
> > register to scsi devices with the same name:
>
> ...hit send without the log showing two "0:0:0:0" devices being
> registered at the same time.
OK, but just trying to shoot the messenger isn't at all helpful in this
case. We use the 0day test suite as one of our primary bulwarks
against submission bugs and it clearly identified your commit as the
first bad one. Thus either we need your code fixed or we need the test
fixed; can you work with the 0day people to root cause this? Jan can
probably help, just in case it's a patch interaction problem.
Thanks,
James