INFO: task kworker/u8:7:3514 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc1-next-20250613-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7    state:D stack:20552 pid:3514  tgid:3514  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 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+0x6c7/0x1010 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:3235 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3318
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3399
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 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 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
4 locks held by kworker/u8:7/3514:
 #0: ffff888141aa9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3210 [inline]
 #0: ffff888141aa9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3318
 #1: ffffc9000b5f7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #1: ffffc9000b5f7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3318
 #2: ffff88807a6c80e0 (&type->s_umount_key#42){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff888032015410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
 #3: ffff888032015410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
2 locks held by getty/5596:
 #0: ffff8880305870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by syz-executor385/5841:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc1-next-20250613-syzkaller #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+0x3f9/0x770 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: 5841 Comm: syz-executor385 Not tainted 6.16.0-rc1-next-20250613-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:delay_tsc+0x5b/0xc0 arch/x86/lib/delay.c:79
Code: 90 49 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 32 19 29 f6 65 8b 05 7b 34 36 07 85 c0 74 1c f3 90 <bf> 01 00 00 00 e8 6b 17 29 f6 e8 f6 3b 01 00 39 c5 75 0e 0f 01 f9
RSP: 0018:ffffc9000403e130 EFLAGS: 00000082
RAX: 0000000080000002 RBX: 0000000000000899 RCX: 0000000000000000
RDX: 0000000000000095 RSI: ffffffff8be2ea40 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: ffff888024510237 R09: 1ffff110048a2046
R10: dffffc0000000000 R11: ffffffff8b67bb60 R12: 1ffffffff33bb336
R13: 00000000ffffffff R14: 0000009576206be9 R15: 00000000000006ed
FS:  000055556009e380(0000) GS:ffff888125c41000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005560d4396168 CR3: 0000000074120000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2100
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
 serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _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
 gc_data_segment fs/f2fs/gc.c:1638 [inline]
 do_garbage_collect+0x3866/0x64b0 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+0x653/0xaf0 fs/f2fs/file.c:1875
 f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:1978
 vfs_fallocate+0x6a0/0x830 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: 0033:0x7f9afba0fbd9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc1099b398 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00002000000000c0 RCX: 00007f9afba0fbd9
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00002000000000e0 R08: 000055556009f4c0 R09: 000055556009f4c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000d0
R13: 00002000000000c8 R14: 00002000000000c2 R15: 00007f9afba5803b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.491 msecs