BTRFS info (device loop4): last unmount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 1 PID: 4333 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 add_chain_cache kernel/locking/lockdep.c:-1 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3772 [inline] validate_chain kernel/locking/lockdep.c:3793 [inline] __lock_acquire+0x1864/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 do_write_seqcount_begin_nested include/linux/seqlock.h:515 [inline] do_write_seqcount_begin include/linux/seqlock.h:541 [inline] psi_account_irqtime+0x320/0x7b4 kernel/sched/psi.c:1035 __schedule+0x784/0x1b0c kernel/sched/core.c:6556 preempt_schedule_irq+0x8c/0x1ac kernel/sched/core.c:6874 arm64_preempt_schedule_irq+0x44/0x54 arch/arm64/kernel/entry-common.c:265 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline] el1_interrupt+0x3c/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_acquire+0x24c/0x63c kernel/locking/lockdep.c:5665 __flush_workqueue+0x130/0x104c kernel/workqueue.c:2812 drain_workqueue+0xa4/0x310 kernel/workqueue.c:2977 destroy_workqueue+0x80/0x9c0 kernel/workqueue.c:4423 btrfs_stop_all_workers+0x15c/0x290 fs/btrfs/disk-io.c:2085 close_ctree+0x594/0xa94 fs/btrfs/disk-io.c:4764 btrfs_put_super+0x70/0x80 fs/btrfs/super.c:397 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_anon_super+0x4c/0x80 fs/super.c:1128 btrfs_kill_super+0x40/0x58 fs/btrfs/super.c:2448 deactivate_locked_super+0xac/0x120 fs/super.c:332 deactivate_super+0xe4/0x104 fs/super.c:363 cleanup_mnt+0x390/0x418 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1ec/0x278 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1fa0/0x2aa4 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585