INFO: rcu detected stall in balance_dirty_pages_ratelimited

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 08b5fa819970 Merge branch 'for-linus' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14e4046a400000
kernel config: https://syzkaller.appspot.com/x/.config?x=79e695838ce7a210
dashboard link: https://syzkaller.appspot.com/bug?extid=83037daa08d221450ffe
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [ak...@linux-foundation.org ax...@kernel.dk
gth...@google.com ja...@suse.cz kees...@chromium.org laoar...@gmail.com
linux-...@vger.kernel.org linu...@kvack.org mawi...@microsoft.com
mho...@suse.com]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+83037d...@syzkaller.appspotmail.com

RAX: ffffffffffffffda RBX: 00007f0c63de86d4 RCX: 0000000000457089
RDX: 0000000000000001 RSI: 0000000020bc2000 RDI: 0000000000000004
RBP: 00000000009300a0 R08: 0000000020606fe4 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00000000004d4190 R14: 00000000004c8b54 R15: 0000000000000001
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 0-....: (105000 ticks this GP) idle=76a/1/0x4000000000000002
softirq=144952/144952 fqs=26032
rcu: (t=105010 jiffies g=334085 q=1885)
NMI backtrace for cpu 0
CPU: 0 PID: 30128 Comm: syz-executor6 Not tainted 4.18.0+ #197
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:162 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
print_cpu_stall.cold.78+0x2fb/0x59c kernel/rcu/tree.c:1478
check_cpu_stall kernel/rcu/tree.c:1550 [inline]
__rcu_pending kernel/rcu/tree.c:3276 [inline]
rcu_pending kernel/rcu/tree.c:3319 [inline]
rcu_check_callbacks+0xd93/0x1660 kernel/rcu/tree.c:2665
update_process_times+0x2d/0x70 kernel/time/timer.c:1636
tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
smp_apic_timer_interrupt+0x16d/0x730 arch/x86/kernel/apic/apic.c:1054
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783
[inline]
RIP: 0010:lock_acquire+0x25f/0x540 kernel/locking/lockdep.c:3927
Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 6a 02 00 00 48 83 3d 28
13 92 06 00 0f 84 d4 01 00 00 48 8b bd 20 ff ff ff 57 9d <0f> 1f 44 00 00
48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00
RSP: 0018:ffff8801912ee5e8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1003225dcc2 RCX: 0000000000000000
RDX: 1ffffffff0fe374d RSI: 0000000000000000 RDI: 0000000000000282
RBP: ffff8801912ee6d8 R08: 0000000000000008 R09: 0000000000000004
R10: ffff8801bb228d58 R11: 5f54006f34535a0e R12: ffff8801bb228480
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:244 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:743 [inline]
percpu_ref_tryget_live include/linux/percpu-refcount.h:251 [inline]
css_tryget_online include/linux/cgroup.h:354 [inline]
task_get_css include/linux/cgroup.h:497 [inline]
wb_get_create_current include/linux/backing-dev.h:309 [inline]
balance_dirty_pages_ratelimited+0x187f/0x2200 mm/page-writeback.c:1874
generic_perform_write+0x551/0x6c0 mm/filemap.c:3175
__generic_file_write_iter+0x26e/0x630 mm/filemap.c:3264
ext4_file_write_iter+0x390/0x1450 fs/ext4/file.c:266
call_write_iter include/linux/fs.h:1811 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x6af/0x9d0 fs/read_write.c:487
__kernel_write+0x10c/0x380 fs/read_write.c:506
do_acct_process+0x1148/0x1660 kernel/acct.c:520
slow_acct_process kernel/acct.c:579 [inline]
acct_process+0x6b9/0x87d kernel/acct.c:605
do_exit+0x1afd/0x2760 kernel/exit.c:855
do_group_exit+0x177/0x440 kernel/exit.c:968
get_signal+0x88e/0x1970 kernel/signal.c:2468
do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe66d9d4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fe66d9d56d4 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cb460 R14: 00000000004ee072 R15: 0000000000000000


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.