INFO: task kworker/u8:3:49 blocked for more than 163 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:21864 pid:49    tgid:49    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
 f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
 f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
 f2fs_write_inode+0x3fb/0x5f0 fs/f2fs/inode.c:819
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
 wb_do_writeback fs/fs-writeback.c:2315 [inline]
 wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:2/36:
4 locks held by kworker/u8:3/49:
 #0: ffff888140aaa148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888140aaa148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000b97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000b97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff888029dae0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff88807af11410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
 #3: ffff88807af11410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
2 locks held by getty/5589:
 #0: ffff8880355620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
11 locks held by syz.1.64/6568:
2 locks held by syz.7.236/8479:
 #0: ffff888029dae0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff888029dae0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff88814378a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff88814378a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz-executor/9174:
 #0: ffff88807c69e0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807c69e0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807c69e0e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
1 lock held by syz-executor/9221:
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
1 lock held by dhcpcd-run-hook/9790:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6568 Comm: syz.1.64 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:sched_core_enabled kernel/sched/sched.h:1364 [inline]
RIP: 0010:sched_core_idle_cpu+0x4f/0x200 kernel/sched/syscalls.c:253
Code: df 48 8d 1c dd 60 2c b9 8d 49 89 dd 49 c1 ed 03 43 80 7c 25 00 00 74 08 48 89 df e8 0b 4b 88 00 49 c7 c6 00 5e 9b 92 4c 03 33 <0f> 1f 44 00 00 83 fd 08 0f 83 bb 00 00 00 43 80 7c 25 00 00 74 08
RSP: 0018:ffffc90000007f28 EFLAGS: 00000087
RAX: 0000000000000000 RBX: ffffffff8db92c60 RCX: 61d7197f54872e00
RDX: 0000000000010000 RSI: ffffffff8be1b920 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8f9fdaf7 R09: 1ffffffff1f3fb5e
R10: dffffc0000000000 R11: fffffbfff1f3fb5f R12: dffffc0000000000
R13: 1ffffffff1b7258c R14: ffff8880b8639e00 R15: dffffc0000000000
FS:  00007ff8730596c0(0000) GS:ffff888125c84000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f88cdef0440 CR3: 000000003132c000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 tick_irq_exit kernel/softirq.c:645 [inline]
 __irq_exit_rcu+0xd8/0x1f0 kernel/softirq.c:686
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449
Code: 85 32 01 00 00 e8 e1 63 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 d0 63 1f 00 eb 06 e8 c9 63 1f 00 fb 48 c7 c7 a0 30 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 36
RSP: 0018:ffffc90003a4e540 EFLAGS: 00000293
RAX: ffffffff81a0e9c7 RBX: ffffffff81a0e884 RCX: ffff88802600bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e1330a0
RBP: ffffc90003a4e650 R08: ffffffff8f9fdaf7 R09: 1ffffffff1f3fb5e
R10: dffffc0000000000 R11: fffffbfff1f3fb5f R12: dffffc0000000000
R13: 1ffff92000749cac R14: 0000000000000200 R15: 0000000000000066
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 bio_check_eod block/blk-core.c:563 [inline]
 submit_bio_noacct+0x108b/0x1a70 block/blk-core.c:796
 f2fs_submit_page_read+0x116/0x190 fs/f2fs/data.c:1113
 f2fs_get_read_data_folio+0x4a4/0x7d0 fs/f2fs/data.c:1271
 f2fs_get_lock_data_folio+0x54/0x1f0 fs/f2fs/data.c:1322
 move_data_page fs/f2fs/gc.c:1457 [inline]
 gc_data_segment fs/f2fs/gc.c:1681 [inline]
 do_garbage_collect+0x3025/0x64b0 fs/f2fs/gc.c:1823
 f2fs_gc+0xc69/0x2540 fs/f2fs/gc.c:1927
 f2fs_balance_fs+0x5a3/0x750 fs/f2fs/segment.c:465
 f2fs_map_blocks+0x3c19/0x4510 fs/f2fs/data.c:1791
 f2fs_expand_inode_data+0x748/0xc10 fs/f2fs/file.c:1909
 f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:2012
 vfs_fallocate+0x6a3/0x830 fs/open.c:341
 ioctl_preallocate fs/ioctl.c:290 [inline]
 file_ioctl+0x611/0x780 fs/ioctl.c:-1
 do_vfs_ioctl+0xe80/0x1990 fs/ioctl.c:886
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff87218e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff873059038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff8723b6080 RCX: 00007ff87218e929
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000005
RBP: 00007ff872210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff8723b6080 R15: 00007ffc77cb32a8
 </TASK>