Re: [lkp-robot] [scsi, block] 0dba1314d4: WARNING:at_fs/sysfs/dir.c:#sysfs_warn_dup

From: James Bottomley
Date: Mon Feb 06 2017 - 19:14:46 EST

On Sun, 2017-02-05 at 21:13 -0800, Dan Williams wrote:
> On Sun, Feb 5, 2017 at 1:13 AM, Christoph Hellwig <hch@xxxxxx> wrote:
> > Dan,
> >
> > can you please quote your emails? I can't find any content
> > inbetween all these quotes.
>
> Sorry, I'm using gmail, but I'll switch to attaching the logs.
>
> So with help from Xiaolong I was able to reproduce this, and it does
> not appear to be a regression. We simply change the failure output of
> an existing bug. Attached is a log of the same test on v4.10-rc7
> (i.e. without the recent block/scsi fixes), and it shows sda being
> registered twice.
>
> "[ 6.647077] kobject (d5078ca4): tried to init an initialized
> object, something is seriously wrong."
>
> The change that "scsi, block: fix duplicate bdi name registration
> crashes" makes is to properly try to register sdb since the sda devt
> is still alive. However that's not a fix because we've managed to
> call blk_register_queue() twice on the same queue.

OK, time to involve others: linux-scsi and linux-block cc'd and I've
inserted the log below.

James

---

[ 5.969672] scsi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---
[ 5.969672] scsi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---
[ 5.969672] scsi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---
[ 5.969672] scsi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---
[ 5.969672] scsi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---
csi host0: scsi_debug: version 1.86 [20160430]
[ 5.969672] dev_size_mb=8, opts=0x0, submit_queues=1, statistics=0
[ 5.971895] scsi 0:0:0:0: Direct-Access Linux scsi_debug 0186 PQ: 0 ANSI: 7
[ 6.006983] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.026965] sd 0:0:0:0: [sda] Write Protect is off
[ 6.027870] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.066962] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.486962] sd 0:0:0:0: [sda] Attached SCSI disk
[ 6.488377] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 6.489455] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 6.526982] sd 0:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
[ 6.546964] sd 0:0:0:0: [sda] Write Protect is off
[ 6.547873] sd 0:0:0:0: [sda] Mode Sense: 73 00 10 08
[ 6.586963] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
[ 6.647077] kobject (d5078ca4): tried to init an initialized object, something is seriously wrong.
[ 6.648723] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.649811] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.651418] Workqueue: events_unbound async_run_entry_fn
[ 6.652347] Call Trace:
[ 6.652987] dump_stack+0x79/0xa4
[ 6.653716] kobject_init+0x75/0x90
[ 6.654452] blk_mq_register_dev+0x2a/0x110
[ 6.655269] blk_register_queue+0x7b/0x130
[ 6.656080] device_add_disk+0x1c6/0x460
[ 6.656866] sd_probe_async+0xf1/0x1c0
[ 6.657634] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.658501] async_run_entry_fn+0x30/0x190
[ 6.659311] ? process_one_work+0x12f/0x430
[ 6.660113] process_one_work+0x1aa/0x430
[ 6.660901] ? process_one_work+0x12f/0x430
[ 6.661716] worker_thread+0x1dd/0x470
[ 6.662479] kthread+0xd4/0x100
[ 6.663175] ? process_one_work+0x430/0x430
[ 6.663984] ? __kthread_create_on_node+0x180/0x180
[ 6.664869] ret_from_fork+0x21/0x2c
[ 6.665638] kobject (ffab51ec): tried to init an initialized object, something is seriously wrong.
[ 6.667290] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.668372] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.669984] Workqueue: events_unbound async_run_entry_fn
[ 6.670909] Call Trace:
[ 6.671540] dump_stack+0x79/0xa4
[ 6.672266] kobject_init+0x75/0x90
[ 6.673011] blk_mq_register_dev+0x4c/0x110
[ 6.673832] blk_register_queue+0x7b/0x130
[ 6.674633] device_add_disk+0x1c6/0x460
[ 6.675413] sd_probe_async+0xf1/0x1c0
[ 6.676191] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.677057] async_run_entry_fn+0x30/0x190
[ 6.677860] ? process_one_work+0x12f/0x430
[ 6.678667] process_one_work+0x1aa/0x430
[ 6.679455] ? process_one_work+0x12f/0x430
[ 6.680269] worker_thread+0x1dd/0x470
[ 6.681036] kthread+0xd4/0x100
[ 6.681737] ? process_one_work+0x430/0x430
[ 6.682540] ? __kthread_create_on_node+0x180/0x180
[ 6.683420] ret_from_fork+0x21/0x2c
[ 6.684207] ------------[ cut here ]------------
[ 6.685067] WARNING: CPU: 0 PID: 99 at ./include/linux/kref.h:46 kobject_get+0x7f/0x90
[ 6.686592] CPU: 0 PID: 99 Comm: kworker/u2:1 Not tainted 4.10.0-rc7 #932
[ 6.687680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[ 6.689280] Workqueue: events_unbound async_run_entry_fn
[ 6.690208] Call Trace:
[ 6.690843] dump_stack+0x79/0xa4
[ 6.691563] __warn+0xd2/0xf0
[ 6.692246] ? kobject_get+0x7f/0x90
[ 6.692992] warn_slowpath_null+0x25/0x30
[ 6.693787] kobject_get+0x7f/0x90
[ 6.694505] kobject_add_internal+0x2e/0x360
[ 6.695322] ? kfree_const+0x18/0x20
[ 6.696071] ? kobject_set_name_vargs+0x62/0x80
[ 6.696914] kobject_add+0x35/0x80
[ 6.697642] blk_mq_register_hctx+0x95/0xc0
[ 6.698447] blk_mq_register_dev+0xc9/0x110
[ 6.699255] blk_register_queue+0x7b/0x130
[ 6.700059] device_add_disk+0x1c6/0x460
[ 6.700849] sd_probe_async+0xf1/0x1c0
[ 6.701628] ? __lock_acquire.isra.14+0x43b/0x940
[ 6.702484] async_run_entry_fn+0x30/0x190
[ 6.703284] ? process_one_work+0x12f/0x430
[ 6.704098] process_one_work+0x1aa/0x430
[ 6.704894] ? process_one_work+0x12f/0x430
[ 6.705704] worker_thread+0x1dd/0x470
[ 6.706488] kthread+0xd4/0x100
[ 6.707198] ? process_one_work+0x430/0x430
[ 6.708016] ? __kthread_create_on_node+0x180/0x180
[ 6.708909] ret_from_fork+0x21/0x2c
[ 6.709676] ---[ end trace 1a7726d7c3d3c8d0 ]---