syzbot


INFO: task hung in gfs2_aspace_writepages

Status: auto-obsoleted due to no activity on 2025/12/11 00:19
Subsystems: gfs2
[Documentation on labels]
First crash: 125d, last: 73d

Sample crash report:
INFO: task kworker/0:1H:56 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:25992 pid:56    tgid:56    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: gfs2-glock/syz:syz glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 io_schedule+0x80/0xd0 kernel/sched/core.c:7871
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __wait_on_bit_lock+0xec/0x4f0 kernel/sched/wait_bit.c:93
 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:120
 lock_buffer include/linux/buffer_head.h:432 [inline]
 gfs2_aspace_write_folio fs/gfs2/meta_io.c:56 [inline]
 gfs2_aspace_writepages+0x2bd/0x600 fs/gfs2/meta_io.c:96
 do_writepages+0x32e/0x550 mm/page-writeback.c:2604
 filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
 __filemap_fdatawrite_range mm/filemap.c:422 [inline]
 filemap_fdatawrite_range+0x1a5/0x250 mm/filemap.c:440
 gfs2_rgrp_metasync fs/gfs2/glops.c:179 [inline]
 rgrp_go_sync+0x23d/0x490 fs/gfs2/glops.c:209
 do_xmote+0x325/0x1060 fs/gfs2/glock.c:704
 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1080
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor:5826 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21320 pid:5826  tgid:5826  ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4273
 flush_work kernel/workqueue.c:4294 [inline]
 flush_delayed_work+0x13e/0x190 kernel/workqueue.c:4316
 gfs2_clear_rgrpd+0xd7/0x690 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x8a7/0x950 fs/gfs2/super.c:635
 generic_shutdown_super+0x135/0x2c0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1722
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcc1fb901f7
RSP: 002b:00007ffd59d2e018 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fcc1fc11d7d RCX: 00007fcc1fb901f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd59d2e0d0
RBP: 00007ffd59d2e0d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd59d2f160
R13: 00007fcc1fc11d7d R14: 000000000002486c R15: 00007ffd59d2f1a0
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/0:0/9:
 #0: ffff8880b863a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
 #1: ffff8880b8624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffff8880b86344d8 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
 #2: ffff8880b86344d8 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: srcu_invoke_callbacks+0x30b/0x450 kernel/rcu/srcutree.c:1826
 #3: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #3: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #3: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 #3: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
1 lock held by khungtaskd/31:
 #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/0:1H/56:
 #0: ffff88807ad68948 ((wq_completion)gfs2-glock/syz:syz){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88807ad68948 ((wq_completion)gfs2-glock/syz:syz){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9000131fba0 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9000131fba0 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by getty/5589:
 #0: ffff88814e1700a0 (&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
1 lock held by syz-executor/5826:
 #0: ffff888058b2c0e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888058b2c0e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888058b2c0e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz.6.673/8900:
 #0: ffffffff8e142c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 e1 1b 00 f3 0f 1e fa fb f4 <e9> c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: cef094f8724a5700 RBX: ffffffff8196bc07 RCX: cef094f8724a5700
RDX: 0000000000000001 RSI: ffffffff8d7e9b20 RDI: ffffffff8bc079e0
RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb
R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e1870
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039deb58
FS:  0000000000000000(0000) GS:ffff888125e0b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560e3cf21d51 CR3: 00000000711c6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e7/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/12 00:08 linux-next 2b763d465239 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in gfs2_aspace_writepages
2025/10/11 23:05 linux-next 2b763d465239 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in gfs2_aspace_writepages
2025/10/05 21:10 linux-next 47a8d4b89844 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in gfs2_aspace_writepages
2025/08/20 16:01 linux-next 5303936d609e bd178e57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in gfs2_aspace_writepages
* Struck through repros no longer work on HEAD.