INFO: task hung in inode_sleep_on_writeback
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syzbot
Mar 31, 2018, 5:01:03 PM3/31/18
to syzkaller-upst...@googlegroups.com
Hello,
syzbot hit the following crash on upstream commit
0b412605ef5f5c64b31f19e2910b1d5eba9929c3 (Thu Mar 29 01:07:23 2018 +0000)
Merge tag 'drm-fixes-for-v4.16-rc8' of
git://people.freedesktop.org/~airlied/linux
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=c5c8b1d5d0cf2b64e632
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5639948577275904
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-8440362230543204781
compiler: gcc (GCC) 7.1.1 20170620
user-space arch: i386
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org
vi...@zeniv.linux.org.uk]
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c5c8b1...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.
Buffer I/O error on dev loop7, logical block 29, async page read
Buffer I/O error on dev loop7, logical block 30, async page read
Buffer I/O error on dev loop7, logical block 31, async page read
Buffer I/O error on dev loop7, logical block 16, lost async page write
Buffer I/O error on dev loop7, logical block 9, lost async page write
INFO: task kworker/u4:5:5982 blocked for more than 120 seconds.
Not tainted 4.16.0-rc7+ #280
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:5 D17072 5982 2 0x80000000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
inode_sleep_on_writeback+0x19e/0x220 fs/fs-writeback.c:1235
wb_writeback+0x568/0xdb0 fs/fs-writeback.c:1794
wb_check_old_data_flush fs/fs-writeback.c:1866 [inline]
wb_do_writeback fs/fs-writeback.c:1919 [inline]
wb_workfn+0xf6d/0x16b0 fs/fs-writeback.c:1948
process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
worker_thread+0x223/0x1990 kernel/workqueue.c:2247
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Showing all locks held in the system:
3 locks held by kworker/u4:1/21:
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at:
[<000000004ab6059e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (&type->s_umount_key#33){++++}, at: [<00000000670c72d9>]
trylock_super+0x20/0x100 fs/super.c:395
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000222724ea>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000222724ea>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<00000000bddedd85>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
2 locks held by getty/4406:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4407:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4408:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4409:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4410:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4411:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4412:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by kworker/u4:5/5982:
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at:
[<000000004ab6059e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 868 Comm: khungtaskd Not tainted 4.16.0-rc7+ #280
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
check_hung_task kernel/hung_task.c:132 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
watchdog+0x90c/0xd60 kernel/hung_task.c:249
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10
arch/x86/include/asm/irqflags.h:54
---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzk...@googlegroups.com.
syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.
To upstream this report, please reply with:
#syz upstream
syzbot hit the following crash on upstream commit
0b412605ef5f5c64b31f19e2910b1d5eba9929c3 (Thu Mar 29 01:07:23 2018 +0000)
Merge tag 'drm-fixes-for-v4.16-rc8' of
git://people.freedesktop.org/~airlied/linux
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=c5c8b1d5d0cf2b64e632
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5639948577275904
Kernel config:
https://syzkaller.appspot.com/x/.config?id=-8440362230543204781
compiler: gcc (GCC) 7.1.1 20170620
user-space arch: i386
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org
vi...@zeniv.linux.org.uk]
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c5c8b1...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.
Buffer I/O error on dev loop7, logical block 29, async page read
Buffer I/O error on dev loop7, logical block 30, async page read
Buffer I/O error on dev loop7, logical block 31, async page read
Buffer I/O error on dev loop7, logical block 16, lost async page write
Buffer I/O error on dev loop7, logical block 9, lost async page write
INFO: task kworker/u4:5:5982 blocked for more than 120 seconds.
Not tainted 4.16.0-rc7+ #280
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:5 D17072 5982 2 0x80000000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
inode_sleep_on_writeback+0x19e/0x220 fs/fs-writeback.c:1235
wb_writeback+0x568/0xdb0 fs/fs-writeback.c:1794
wb_check_old_data_flush fs/fs-writeback.c:1866 [inline]
wb_do_writeback fs/fs-writeback.c:1919 [inline]
wb_workfn+0xf6d/0x16b0 fs/fs-writeback.c:1948
process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
worker_thread+0x223/0x1990 kernel/workqueue.c:2247
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Showing all locks held in the system:
3 locks held by kworker/u4:1/21:
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at:
[<000000004ab6059e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (&type->s_umount_key#33){++++}, at: [<00000000670c72d9>]
trylock_super+0x20/0x100 fs/super.c:395
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000222724ea>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000222724ea>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<00000000bddedd85>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
2 locks held by getty/4406:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4407:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4408:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4409:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4410:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4411:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4412:
#0: (&tty->ldisc_sem){++++}, at: [<00000000f33d3480>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<000000007ceb0c23>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by kworker/u4:5/5982:
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"writeback"){+.+.}, at: [<0000000047a66494>]
process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at:
[<000000004ab6059e>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 868 Comm: khungtaskd Not tainted 4.16.0-rc7+ #280
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
check_hung_task kernel/hung_task.c:132 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
watchdog+0x90c/0xd60 kernel/hung_task.c:249
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10
arch/x86/include/asm/irqflags.h:54
---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzk...@googlegroups.com.
syzbot will keep track of this bug report.
If you forgot to add the Reported-by tag, once the fix for this bug is
merged
into any tree, please reply to this email with:
#syz fix: exact-commit-title
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug
report.
Note: all commands must start from beginning of the line in the email body.
To upstream this report, please reply with:
#syz upstream
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