Re: [lkp-robot] [scsi, block] 0dba1314d4: WARNING:at_fs/sysfs/dir.c:#sysfs_warn_dup
From: Dan Williams
Date: Sat Feb 04 2017 - 15:37:41 EST
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.
[ 7.872969] scsi 0:0:0:0: Direct-Access Linux scsi_debug
0186 PQ: 0 ANSI: 7
[ 7.905516] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39
MB/8.00 MiB)
[ 7.935502] sd 0:0:0:0: [sda] Write Protect is off
[ 7.936460] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 7.975491] sd 0:0:0:0: [sda] Write cache: enabled, read cache:
enabled, supports DPO and FUA
[ 8.395505] sd 0:0:0:0: [sda] Attached SCSI disk
[ 8.397174] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 8.398364] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 8.435526] sd 0:0:0:0: [sdb] 16384 512-byte logical blocks: (8.39
MB/8.00 MiB)
[ 8.455497] sd 0:0:0:0: [sdb] Write Protect is off
[ 8.456461] sd 0:0:0:0: [sdb] Mode Sense: 73 00 10 08
[ 8.495492] sd 0:0:0:0: [sdb] Write cache: enabled, read cache:
enabled, supports DPO and FUA
[ 8.555658] kobject (c9cad6a4): tried to init an initialized
object, something is seriously wrong.
[ 8.557439] CPU: 0 PID: 102 Comm: kworker/u2:1 Not tainted
4.10.0-rc5-00097-g0dba131 #1
[ 8.559082] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[ 8.560960] Workqueue: events_unbound async_run_entry_fn
[ 8.561946] Call Trace:
[ 8.562635] dump_stack+0x79/0xa4
[ 8.563411] kobject_init+0x75/0x90
[ 8.564202] blk_mq_register_dev+0x2a/0x120
[ 8.565076] blk_register_queue+0x7b/0x130
[ 8.565939] device_add_disk+0x1e3/0x480
[ 8.566783] sd_probe_async+0xf1/0x1c0
[ 8.567597] ? __lock_acquire+0x43b/0x940
[ 8.568508] async_run_entry_fn+0x30/0x190
[ 8.569356] ? process_one_work+0x12f/0x430
[ 8.570220] process_one_work+0x1aa/0x430
[ 8.571068] ? process_one_work+0x12f/0x430
[ 8.571933] worker_thread+0x1dd/0x470
[ 8.572755] kthread+0xd4/0x100
[ 8.573509] ? process_one_work+0x430/0x430
[ 8.574373] ? __kthread_create_on_node+0x180/0x180
[ 8.575305] ret_from_fork+0x21/0x2c