INFO: task syz.3.8:5348 blocked for more than 143 seconds.
      Not tainted 6.11.0-syzkaller-10669-g11a299a7933e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.8         state:D stack:22272 pid:5348  tgid:5316  ppid:5226   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 io_schedule+0x8d/0x110 kernel/sched/core.c:7552
 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1309
 folio_wait_writeback+0xe7/0x1e0 mm/page-writeback.c:3189
 truncate_inode_pages_range+0xafd/0xfc0 mm/truncate.c:398
 bchfs_fallocate+0x2d1/0x730 fs/bcachefs/fs-io.c:718
 bch2_fallocate_dispatch+0x3ac/0x540 fs/bcachefs/fs-io.c:771
 vfs_fallocate+0x569/0x6e0 fs/open.c:333
 do_vfs_ioctl+0x2583/0x2e40 fs/ioctl.c:886
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f849a57df39
RSP: 002b:00007f8499fde038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f849a736130 RCX: 00007f849a57df39
RDX: 0000000020000180 RSI: 0000000040305839 RDI: 0000000000000009
RBP: 00007f849a5f0216 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f849a736130 R15: 00007ffd21dc96c8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/0:1/9:
 #0: ffff8880b863ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593
 #1: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989
1 lock held by khungtaskd/30:
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701
2 locks held by kworker/u8:9/2909:
1 lock held by udevd/4676:
 #0: ffff8880b863ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593
2 locks held by getty/4981:
 #0: ffff88802f02b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz.3.8/5317:
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679
1 lock held by syz.3.8/5345:
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: vfs_writev+0x2d1/0xba0 fs/read_write.c:1062
2 locks held by syz.3.8/5348:
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888027494420 (sb_writers#16){.+.+}-{0:0}, at: vfs_fallocate+0x4fe/0x6e0 fs/open.c:332
 #1: ffff888058c088c0 (&sb->s_type->i_mutex_key#21){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #1: ffff888058c088c0 (&sb->s_type->i_mutex_key#21){++++}-{3:3}, at: bch2_fallocate_dispatch+0x1e2/0x540 fs/bcachefs/fs-io.c:762
1 lock held by bch-copygc/loop/5338:
1 lock held by syz-executor/6015:
 #0: ffffffff8e93d478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #0: ffffffff8e93d478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
2 locks held by syz.4.104/6220:
 #0: ffff8880274940e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880274940e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff888027494938 (&s->s_sync_lock){+.+.}-{3:3}, at: wait_sb_inodes fs/fs-writeback.c:2619 [inline]
 #1: ffff888027494938 (&s->s_sync_lock){+.+.}-{3:3}, at: sync_inodes_sb+0x32e/0xb50 fs/fs-writeback.c:2802
2 locks held by syz.3.132/6356:
 #0: ffff8880274940e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880274940e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff888027494938 (&s->s_sync_lock){+.+.}-{3:3}, at: wait_sb_inodes fs/fs-writeback.c:2619 [inline]
 #1: ffff888027494938 (&s->s_sync_lock){+.+.}-{3:3}, at: sync_inodes_sb+0x32e/0xb50 fs/fs-writeback.c:2802

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-10669-g11a299a7933e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5338 Comm: bch-copygc/loop Not tainted 6.11.0-syzkaller-10669-g11a299a7933e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d 64 7d 9b 0c 48 89 de 5b e9 f3 a1 5a 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 80 d7 03 00 65 8b 15 80 22
RSP: 0018:ffffc900042ce4b8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888024d242d8
RDX: ffff88807f161e00 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 1ffff1100466d813 R08: ffffffff8414d7a9 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff203772e R12: ffff88802336c000
R13: dffffc0000000000 R14: ffff88802336c098 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c6cf06ab8 CR3: 000000000e734000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 bch2_btree_path_level_init+0x447/0x9f0 fs/bcachefs/btree_iter.c:634
 btree_path_lock_root fs/bcachefs/btree_iter.c:769 [inline]
 bch2_btree_path_traverse_one+0x10de/0x2940 fs/bcachefs/btree_iter.c:1170
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2197 [inline]
 bch2_btree_iter_peek_upto+0xb58/0x6f00 fs/bcachefs/btree_iter.c:2297
 bch2_btree_iter_peek_upto_type fs/bcachefs/btree_iter.h:685 [inline]
 bch2_get_next_backpointer+0x8bb/0x1320 fs/bcachefs/backpointers.c:246
 bch2_evacuate_bucket+0x1075/0x34e0 fs/bcachefs/move.c:708
 bch2_copygc+0x3a03/0x4650 fs/bcachefs/movinggc.c:234
 bch2_copygc_thread+0x737/0xc20 fs/bcachefs/movinggc.c:375
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>