INFO: task bch-reclaim/loo:7653 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:bch-reclaim/loo state:D stack:26856 pid:7653 tgid:7653 ppid:2 task_flags:0x200840 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 btree_write_buffer_flush_seq+0x1829/0x19a0 fs/bcachefs/btree_write_buffer.c:569 bch2_btree_write_buffer_journal_flush+0x69/0xb0 fs/bcachefs/btree_write_buffer.c:586 journal_flush_pins+0x8e0/0xe90 fs/bcachefs/journal_reclaim.c:592 __bch2_journal_reclaim+0x781/0xd10 fs/bcachefs/journal_reclaim.c:723 bch2_journal_reclaim_thread+0x177/0x4f0 fs/bcachefs/journal_reclaim.c:765 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 4 locks held by kworker/0:1/10: #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 #2: ffffc90002ff78c8 (&x->wait#11){....}-{2:2}, at: complete_with_flags kernel/sched/completion.c:20 [inline] #2: ffffc90002ff78c8 (&x->wait#11){....}-{2:2}, at: complete+0x28/0x1b0 kernel/sched/completion.c:47 #3: ffff88802a286428 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #3: ffff88802a286428 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x6e/0x1290 kernel/sched/core.c:4212 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5581: #0: ffff888034e5a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036d32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/5951: 2 locks held by syz-executor/6238: #0: ffff88805c7b60e0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805c7b60e0 (&type->s_umount_key#61){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805c7b60e0 (&type->s_umount_key#61){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffff88804c200278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xfe/0x5a0 fs/bcachefs/super.c:622 1 lock held by syz-executor/6702: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 3 locks held by bch-reclaim/loo/7653: #0: ffff88804c24ad28 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:764 #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385 #2: ffff88804c2045d0 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x1829/0x19a0 fs/bcachefs/btree_write_buffer.c:569 3 locks held by bch-copygc/loop/7654: #0: ffff88804c2045d0 (&wb->flushing.lock){+.+.}-{4:4}, at: bch2_btree_write_buffer_flush_nocheck_rw fs/bcachefs/btree_write_buffer.c:620 [inline] #0: ffff88804c2045d0 (&wb->flushing.lock){+.+.}-{4:4}, at: bch2_btree_write_buffer_tryflush+0x130/0x1a0 fs/bcachefs/btree_write_buffer.c:635 #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff88804c204228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202 #2: ffff88804c226590 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by syz.0.444/10051: 2 locks held by syz.4.445/10075: 1 lock held by sed/10083: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: 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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10075 Comm: syz.4.445 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x46b/0xd20 kernel/locking/lockdep.c:5185 Code: c1 41 ff ce 49 ff cc f7 c1 00 60 00 00 74 cf eb 1c 48 c7 c7 b0 ca e0 8d 48 89 de e8 2f 89 48 03 48 8b 3c 24 41 8b 47 20 eb ca <45> 89 ee 65 8b 05 27 14 d4 10 85 c0 0f 84 07 01 00 00 41 b4 03 83 RSP: 0018:ffffc9000bafef58 EFLAGS: 00000086 RAX: 0000000000020007 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff888030e01e00 RBP: ffff888030e028f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8171a9f5 R12: ffffffffffffffff R13: 0000000000000000 R14: 0000000000000001 R15: ffff888030e02940 FS: 00007f7845f136c0(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000002f81a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2320 shmem_alloc_folio mm/shmem.c:1854 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1893 shmem_get_folio_gfp+0x597/0x15f0 mm/shmem.c:2533 shmem_get_folio mm/shmem.c:2639 [inline] shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3289 generic_perform_write+0x2c4/0x910 mm/filemap.c:4103 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3464 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f784518d41f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f7845f12df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f784518d41f RDX: 0000000001000000 RSI: 00007f783aa00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050e7 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f7845f12ef0 R14: 00007f7845f12eb0 R15: 00007f783aa00000