F2FS-fs (loop0): Stopped filesystem due to reason: 3 ============================= WARNING: suspicious RCU usage syzkaller #0 Not tainted ----------------------------- fs/btrfs/volumes.h:872 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by kworker/u8:5/83: #0: ffff8880206b2948 ((wq_completion)blkcg_punt_bio){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9000257fc40 ((work_completion)(&blkg->async_bio_work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 stack backtrace: CPU: 0 UID: 0 PID: 83 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: blkcg_punt_bio blkg_async_bio_workfn Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 btrfs_dev_name fs/btrfs/volumes.h:872 [inline] btrfs_dev_stat_inc_and_print+0x328/0x400 fs/btrfs/volumes.c:8282 btrfs_log_dev_io_error fs/btrfs/bio.c:-1 [inline] btrfs_simple_end_io+0x1e6/0x3e0 fs/btrfs/bio.c:399 blkg_async_bio_workfn+0x156/0x1d0 block/blk-cgroup.c:224 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 BTRFS error (device loop2): bdev /dev/loop2 errs: wr 1, rd 0, flush 0, corrupt 0, gen 0 BTRFS error (device loop2): bdev /dev/loop2 errs: wr 2, rd 0, flush 0, corrupt 0, gen 0 BTRFS error (device loop2): bdev /dev/loop2 errs: wr 3, rd 0, flush 0, corrupt 0, gen 0 BTRFS error (device loop2): bdev /dev/loop2 errs: wr 4, rd 0, flush 0, corrupt 0, gen 0