INFO: task segctord:6508 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. segctord D30128 6508 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:72 nilfs_transaction_lock+0x1fb/0x8b0 fs/nilfs2/segment.c:362 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2479 [inline] nilfs_segctor_thread+0x3c0/0xf50 fs/nilfs2/segment.c:2563 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 000000003a1dfb60 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7800: #0: 00000000cb94d398 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/u4:8/9501: 6 locks held by syz-executor.5/6501: 1 lock held by segctord/6508: #0: 00000000262e762a (&nilfs->ns_segctor_sem){++++}, at: nilfs_transaction_lock+0x1fb/0x8b0 fs/nilfs2/segment.c:362 2 locks held by apt-get/19550: 1 lock held by syz-executor.4/19694: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7801 Comm: rs:main Q:Reg Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:799 [inline] RIP: 0010:lookup_bh_lru fs/buffer.c:1279 [inline] RIP: 0010:__find_get_block+0x264/0xde0 fs/buffer.c:1291 Code: 47 60 eb 03 45 31 e4 e8 9a 0e b2 ff e8 65 32 b7 ff 48 c7 c2 98 82 f1 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 64 0a 00 00 48 83 3d 96 0b 41 08 00 0f 84 bf 04 00 00 e8 63 RSP: 0018:ffff88808f9176a0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff110146bd55f RDX: 1ffffffff13e3053 RSI: ffff8880a35eaad8 RDI: ffff8880a35eaa84 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888096176d20 R13: 0000000000000383 R14: 0000000000001000 R15: ffff888096176d20 FS: 00007f398535e700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff08ea8a000 CR3: 00000000aa5db000 CR4: 00000000003426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __getblk_gfp+0x28/0x70 fs/buffer.c:1317 sb_getblk include/linux/buffer_head.h:333 [inline] __ext4_get_inode_loc+0x351/0x10f0 fs/ext4/inode.c:4621 ext4_get_inode_loc fs/ext4/inode.c:4734 [inline] ext4_reserve_inode_write+0xeb/0x260 fs/ext4/inode.c:5938 ext4_mark_inode_dirty+0x160/0x870 fs/ext4/inode.c:6105 ext4_dirty_inode+0x88/0xb0 fs/ext4/inode.c:6144 __mark_inode_dirty+0x16b/0x1140 fs/fs-writeback.c:2164 mark_inode_dirty include/linux/fs.h:2086 [inline] __generic_write_end+0x26a/0x300 fs/buffer.c:2129 ext4_da_write_end+0x623/0xa70 fs/ext4/inode.c:3201 generic_perform_write+0x2ae/0x4d0 mm/filemap.c:3181 __generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295 ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f3987da21cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f398535d590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f397c002cd0 RCX: 00007f3987da21cd RDX: 00000000000003e1 RSI: 00007f397c002cd0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f397c002a30 R13: 00007f398535d5b0 R14: 00005584fbcb1360 R15: 00000000000003e1