BUG: MAX_LOCKDEP_CHAINS too low!
turning off the locking correctness validator.
CPU: 1 PID: 4497 Comm: kworker/u4:20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
Workqueue: btrfs-qgroup-rescan btrfs_work_helper
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
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x54/0x6c kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __reserve_bytes+0x144/0x1164 fs/btrfs/space-info.c:1665
 btrfs_reserve_metadata_bytes+0x64/0x148 fs/btrfs/space-info.c:1778
 btrfs_use_block_rsv+0x414/0x694 fs/btrfs/block-rsv.c:548
 btrfs_alloc_tree_block+0x15c/0x1164 fs/btrfs/extent-tree.c:5030
 btrfs_force_cow_block+0x3ac/0x188c fs/btrfs/ctree.c:450
 btrfs_cow_block+0x2d0/0x708 fs/btrfs/ctree.c:623
 btrfs_search_slot+0xa50/0x237c fs/btrfs/ctree.c:-1
 lookup_inline_extent_backref+0x28c/0xe74 fs/btrfs/extent-tree.c:847
 lookup_extent_backref fs/btrfs/extent-tree.c:1074 [inline]
 __btrfs_free_extent+0x228/0x22ac fs/btrfs/extent-tree.c:2984
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1696 [inline]
 run_one_delayed_ref fs/btrfs/extent-tree.c:1720 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:1969 [inline]
 __btrfs_run_delayed_refs+0xbb4/0x32f4 fs/btrfs/extent-tree.c:2032
 btrfs_run_delayed_refs+0x124/0x46c fs/btrfs/extent-tree.c:2163
 commit_cowonly_roots+0x550/0x71c fs/btrfs/transaction.c:1328
 btrfs_commit_transaction+0x10e8/0x2884 fs/btrfs/transaction.c:2428
 btrfs_qgroup_rescan_worker+0x14b8/0x152c fs/btrfs/qgroup.c:3423
 btrfs_work_helper+0x324/0xcb0 fs/btrfs/async-thread.c:280
 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292
 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
BTRFS info (device loop9): qgroup scan completed (inconsistency flag cleared)