======================================
| [ 3093.855979][    C2] 1 lock held by ksoftirqd/2/27:
| [ 3093.856258][ C2] #0: ffffffff8d38b540 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [ 3093.856586][    C2]
| [ 3093.856586][    C2] stack backtrace:
[ 3093.856808][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 3093.856810][    C2] Call Trace:
[ 3093.856812][    C2]  <TASK>
[ 3093.856815][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 3093.856821][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 3093.856825][ C2] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 3093.856829][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 3093.856834][ C2] ? save_trace (kernel/locking/lockdep.c:595) 
[ 3093.856839][ C2] mark_lock (kernel/locking/lockdep.c:4756) 
[ 3093.856843][ C2] mark_usage (kernel/locking/lockdep.c:4645) 
[ 3093.856845][ C2] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 3093.856848][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 3093.856852][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 3093.856855][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 3093.856858][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.856861][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 3093.856864][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 3093.856867][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 3093.856870][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 3093.856873][ C2] simple_pin_fs (fs/libfs.c:1067) 
[ 3093.856876][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 3093.856880][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 3093.856885][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 3093.856888][ C2] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 3093.856892][ C2] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 3093.856896][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 3093.856899][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 3093.856903][ C2] ? kthread (kernel/kthread.c:464) 
[ 3093.856907][ C2] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 3093.856910][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 3093.856914][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 3093.856917][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 3093.856922][ C2] __put_net (net/core/net_namespace.c:732) 
[ 3093.856927][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 3093.856930][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 3093.856934][ C2] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 3093.856939][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 3093.856943][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 3093.856946][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.856949][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 3093.856953][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 3093.856958][ C2] handle_softirqs (kernel/softirq.c:580) 
[ 3093.856962][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 3093.856965][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 3093.856968][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 3093.856971][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 3093.856975][ C2] kthread (kernel/kthread.c:464) 
[ 3093.856979][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 3093.856982][ C2] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 3093.856984][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 3093.856987][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.856990][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 3093.856993][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 3093.856996][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 3093.856999][ C2] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [ 3093.868947][    C2] RCU nest depth: 0, expected: 0
| [ 3093.869128][    C2] INFO: lockdep is turned off.
| [ 3093.869300][    C2] Preemption disabled at:
| [ 3093.869301][ C2] handle_softirqs (kernel/softirq.c:553) 
[ 3093.869649][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 3093.869651][    C2] Call Trace:
[ 3093.869653][    C2]  <TASK>
[ 3093.869655][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 3093.869661][ C2] __might_resched (kernel/sched/core.c:8796) 
[ 3093.869668][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 3093.869671][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 3093.869674][ C2] ? simple_recursive_removal (fs/libfs.c:614) 
[ 3093.869678][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.869683][ C2] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 3093.869688][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 3093.869691][ C2] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 3093.869694][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 3093.869700][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 3093.869703][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 3093.869708][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 3093.869710][ C2] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 3093.869714][ C2] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 3093.869719][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 3093.869721][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 3093.869726][ C2] ? kthread (kernel/kthread.c:464) 
[ 3093.869729][ C2] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 3093.869732][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 3093.869736][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 3093.869739][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 3093.869745][ C2] __put_net (net/core/net_namespace.c:732) 
[ 3093.869749][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 3093.869753][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 3093.869756][ C2] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 3093.869762][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 3093.869766][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 3093.869769][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.869772][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 3093.869777][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 3093.869780][ C2] handle_softirqs (kernel/softirq.c:580) 
[ 3093.869784][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 3093.869788][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 3093.869790][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 3093.869793][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 3093.869797][ C2] kthread (kernel/kthread.c:464) 
[ 3093.869801][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 3093.869804][ C2] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 3093.869806][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 3093.869809][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 3093.869812][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 3093.869815][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 3093.869818][ C2] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock
handle_softirqs:dump_stack_lvl:__might_resched:down_write:simple_recursive_removal