syzbot

INFO: task bch-reclaim/loo:6066 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-reclaim/loo state:D stack:18952 pid:6066  tgid:6066  ppid:2      task_flags:0x200040 flags:0x00004000
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
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
 bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:767
 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: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8e1448b8 (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: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
4 locks held by kworker/u8:3/50:
 #0: ffff888026e57948 ((wq_completion)btree_update#67){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888026e57948 ((wq_completion)btree_update#67){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000bb7bc0 ((work_completion)(&c->btree_interior_update_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000bb7bc0 ((work_completion)(&c->btree_interior_update_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #2: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #2: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3255
 #3: ffff888083ca6710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1dc0 fs/bcachefs/btree_update_interior.c:1211
3 locks held by kworker/u8:4/60:
1 lock held by udevd/5199:
 #0: ffff8880271c2948 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x2d9/0x1390 arch/x86/mm/fault.c:1327
2 locks held by getty/5591:
 #0: ffff88814cbbf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by syz-executor332/5840:
 #0: ffff888048c5c0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888048c5c0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888048c5c0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffff888083c80278 (&c->state_lock){+.+.}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:677
 #2: ffff888083ccaf68 (&j->reclaim_lock){+.+.}-{4:4}, at: journal_flush_done+0x86/0x810 fs/bcachefs/journal_reclaim.c:878
 #3: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #3: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #3: ffff888083c84390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80 fs/bcachefs/btree_iter.c:3440
 #4: ffff888083c84738 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x1829/0x19a0 fs/bcachefs/btree_write_buffer.c:572
 #5: ffff888083ca6710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1dc0 fs/bcachefs/btree_update_interior.c:1211
6 locks held by syz-executor332/5843:
 #0: ffff88807e2660e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807e2660e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807e2660e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffff888052800278 (&c->state_lock){+.+.}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:677
 #2: ffff88805284af68 (&j->reclaim_lock){+.+.}-{4:4}, at: journal_flush_done+0x86/0x810 fs/bcachefs/journal_reclaim.c:878
 #3: ffff888052804390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #3: ffff888052804390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #3: ffff888052804390 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80 fs/bcachefs/btree_iter.c:3440
 #4: ffff888052804738 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x1829/0x19a0 fs/bcachefs/btree_write_buffer.c:572
 #5: ffff888052826710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1dc0 fs/bcachefs/btree_update_interior.c:1211
2 locks held by kworker/0:5/5930:
1 lock held by udevd/5969:
1 lock held by bch-reclaim/loo/6066:
 #0: ffff88805284af68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:767
1 lock held by udevd/6141:
 #0: ffff888028f5d588 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x2d9/0x1390 arch/x86/mm/fault.c:1327
1 lock held by bch-reclaim/loo/6914:
 #0: ffff888083ccaf68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:767
3 locks held by syz-executor332/8057:
2 locks held by syz-executor332/8065:
 #0: ffff888037c00278 (&c->state_lock){+.+.}-{4:4}, at: bch2_fs_read_write_early+0x1e/0x40 fs/bcachefs/super.c:575
 #1: ffffffff8dfe57a8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5181 [inline]
 #1: ffffffff8dfe57a8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9eb/0x1b70 kernel/workqueue.c:5736
1 lock held by syz-executor332/8072:
 #0: ffffffff8dfe57a8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5181 [inline]
 #0: ffffffff8dfe57a8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9eb/0x1b70 kernel/workqueue.c:5736

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #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: 8057 Comm: syz-executor332 Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__list_add include/linux/list.h:150 [inline]
RIP: 0010:list_add include/linux/list.h:169 [inline]
RIP: 0010:lru_gen_add_folio+0x610/0xc70 include/linux/mm_inline.h:278
Code: 00 00 fc ff df 43 80 3c 26 00 74 08 4c 89 ef e8 76 b2 27 00 4d 8b 7d 00 48 8b 7c 24 08 4c 89 ee 4c 89 fa e8 12 73 cb 02 84 c0 <0f> 84 f9 01 00 00 e8 35 34 c4 ff 4c 89 e1 4d 8d 67 08 4c 89 e0 48
RSP: 0018:ffffc90003ee75c0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffffea0001b9d540 RCX: 0000000000000001
RDX: ffffea0001b9d508 RSI: ffff88801cac3320 RDI: ffffea0001b9d548
RBP: ffffc90003ee7690 R08: ffffffff8fa10df7 R09: 1ffffffff1f421be
R10: dffffc0000000000 R11: fffffbfff1f421bf R12: dffffc0000000000
R13: ffff88801cac3320 R14: 1ffff11003958664 R15: ffffea0001b9d508
FS:  00007f21816ea6c0(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 000000009b711000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lruvec_add_folio include/linux/mm_inline.h:344 [inline]
 lru_add+0x6ad/0xd80 mm/swap.c:154
 folio_batch_move_lru+0x21e/0x3a0 mm/swap.c:168
 __folio_batch_add_and_move+0x5ad/0xd20 mm/swap.c:196
 filemap_add_folio+0x1af/0x270 mm/filemap.c:985
 __filemap_get_folio+0x4f6/0xaf0 mm/filemap.c:1990
 bch2_filemap_get_contig_folios_d+0x123/0x480 fs/bcachefs/fs-io-pagecache.c:31
 __bch2_buffered_write fs/bcachefs/fs-io-buffered.c:836 [inline]
 bch2_buffered_write fs/bcachefs/fs-io-buffered.c:1026 [inline]
 bch2_write_iter+0x6f4/0x2b90 fs/bcachefs/fs-io-buffered.c:1082
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x54b/0xa90 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 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: 0033:0x7f2181f46169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 1f 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f21816ea218 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2181fd34a8 RCX: 00007f2181f46169
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f2181fd34a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2181f98374
R13: 00002000000015c0 R14: 00002000000015c8 R15: 0000200000000080
 </TASK>