On Mon, Jan 08, 2024 at 04:50:15PM -0500, Theodore Ts'o wrote:
> Hi, while doing final testing before sending a pull request, I merged
> in linux-next, and commit 5b9ce7ecd7: virtio_balloon: stay awake while
> adjusting balloon seems to be causing a lockdep warning (see attached)
> when running gce-xfstests on a Google Compute Engine e2 VM. I was not
> able to trigger it using kvm-xfstests, but the following command:
> "gce-xfstests -C 10 ext4/4k generic/476) was sufficient to triger the
> problem. For more information please see [1] and [2].
>
> [1]
> https://github.com/tytso/xfstests-bld/blob/master/Documentation/gce-xfstests.md
> [2] https://thunk.org/gce-xfstests
>
> I found it by looking at the git logs, and this commit aroused my
> suspicions, and I further testing showed that the lockdep warning was
> reproducible with this commit, but not when testing with the
> immediately preceeding commit (15b9ce7ecd^).
>
> Cheers,
Thanks a lot for the report!
I pushed a fixed patch out (tree rebased).
Would be great if you can confirm it's allright now.
> - Ted
>
>
> root: ext4/4k run xfstest generic/476
> systemd[1]: Started fstests-generic-476.scope - /usr/bin/bash -c test -w
> /proc/self/oom_score_adj && echo 250 > /proc/self/oom_score_adj; exec
> ./tests/generic/476.
> kernel: [ 399.361181] EXT4-fs (dm-1): mounted filesystem
> 840e25bd-f650-4819-8562-7eded85ef370 r/w with ordered data mode. Quota mode:
> none.
> systemd[1]: fstests-generic-476.scope: Deactivated successfully.
> systemd[1]: fstests-generic-476.scope: Consumed 3min 1.966s CPU time.
> systemd[1]: xt\x2dvdb.mount: Deactivated successfully.
> kernel: [ 537.085404] EXT4-fs (dm-0): unmounting filesystem
> d3d7a675-f7b6-4384-abec-2e60d885b6da.
> systemd[1]: xt\x2dvdc.mount: Deactivated successfully.
> kernel: [ 540.565870]
> kernel: [ 540.567523] ================================
> kernel: [ 540.572007] WARNING: inconsistent lock state
> kernel: [ 540.576407] 6.7.0-rc3-xfstests-lockdep-00012-g5b9ce7ecd715 #318
> Not tainted
> kernel: [ 540.583532] --------------------------------
> kernel: [ 540.587928] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
> kernel: [ 540.594326] kworker/0:3/329 [HC0[0]:SC0[0]:HE1:SE1] takes:
> kernel: [ 540.599955] ffff90b280a548c0 (&vb->adjustment_lock){?...}-{2:2},
> at: update_balloon_size_func+0x33/0x190
> kernel: [ 540.609926] {IN-HARDIRQ-W} state was registered at:
> kernel: [ 540.614935] __lock_acquire+0x3f2/0xb30
> kernel: [ 540.618992] lock_acquire+0xbf/0x2b0
> kernel: [ 540.622786] _raw_spin_lock_irqsave+0x43/0x90
> kernel: [ 540.627366] virtballoon_changed+0x51/0xd0
> kernel: [ 540.631947] virtio_config_changed+0x5a/0x70
> kernel: [ 540.636437] vp_config_changed+0x11/0x20
> kernel: [ 540.640576] __handle_irq_event_percpu+0x88/0x230
> kernel: [ 540.645500] handle_irq_event+0x38/0x80
> kernel: [ 540.649558] handle_edge_irq+0x8f/0x1f0
> kernel: [ 540.653791] __common_interrupt+0x47/0xf0
> kernel: [ 540.658106] common_interrupt+0x79/0xa0
> kernel: [ 540.661672] EXT4-fs (dm-1): unmounting filesystem
> 840e25bd-f650-4819-8562-7eded85ef370.
> kernel: [ 540.663183] asm_common_interrupt+0x26/0x40
> kernel: [ 540.663190] acpi_safe_halt+0x1b/0x30
> kernel: [ 540.663196] acpi_idle_enter+0x7b/0xd0
> kernel: [ 540.663199] cpuidle_enter_state+0x90/0x4f0
> kernel: [ 540.688723] cpuidle_enter+0x2d/0x40
> kernel: [ 540.692516] cpuidle_idle_call+0xe4/0x120
> kernel: [ 540.697036] do_idle+0x84/0xd0
> kernel: [ 540.700393] cpu_startup_entry+0x2a/0x30
> kernel: [ 540.704588] rest_init+0xe9/0x180
> kernel: [ 540.708118] arch_call_rest_init+0xe/0x30
> kernel: [ 540.712426] start_kernel+0x41c/0x4b0
> kernel: [ 540.716310] x86_64_start_reservations+0x18/0x30
> kernel: [ 540.721164] x86_64_start_kernel+0x8c/0x90
> kernel: [ 540.725737] secondary_startup_64_no_verify+0x178/0x17b
> kernel: [ 540.731432] irq event stamp: 22681
> kernel: [ 540.734956] hardirqs last enabled at (22681):
> [<ffffffff8b4b5158>] _raw_spin_unlock_irq+0x28/0x50
> kernel: [ 540.744564] hardirqs last disabled at (22680):
> [<ffffffff8b4b4ded>] _raw_spin_lock_irq+0x5d/0x90
> kernel: [ 540.753475] softirqs last enabled at (22076):
> [<ffffffff8a58cfa1>] srcu_invoke_callbacks+0x101/0x1c0
> kernel: [ 540.762904] softirqs last disabled at (22072):
> [<ffffffff8a58cfa1>] srcu_invoke_callbacks+0x101/0x1c0
> kernel: [ 540.773298]
> kernel: [ 540.773298] other info that might help us debug this:
> kernel: [ 540.780207] Possible unsafe locking scenario:
> kernel: [ 540.780207]
> kernel: [ 540.786438] CPU0
> kernel: [ 540.789007] ----
> kernel: [ 540.791766] lock(&vb->adjustment_lock);
> kernel: [ 540.796014] <Interrupt>
> kernel: [ 540.798778] lock(&vb->adjustment_lock);
> kernel: [ 540.803605]
> kernel: [ 540.803605] *** DEADLOCK ***
> kernel: [ 540.803605]
> kernel: [ 540.809840] 2 locks held by kworker/0:3/329:
> kernel: [ 540.814259] #0: ffff90b280079148
> ((wq_completion)events_freezable){+.+.}-{0:0}, at:
> process_one_work+0x1a6/0x500
> kernel: [ 540.824952] #1: ffff9e3b40d1fe50
> ((work_completion)(&vb->update_balloon_size_work)){+.+.}-{0:0}, at:
> process_one_work+0x1a6/0x500
> kernel: [ 540.837088]
> kernel: [ 540.837088] stack backtrace:
> kernel: [ 540.841584] CPU: 0 PID: 329 Comm: kworker/0:3 Not tainted
> 6.7.0-rc3-xfstests-lockdep-00012-g5b9ce7ecd715 #318
> kernel: [ 540.851632] Hardware name: Google Google Compute Engine/Google
> Compute Engine, BIOS Google 11/17/2023
> kernel: [ 540.861148] Workqueue: events_freezable update_balloon_size_func
> kernel: [ 540.867306] Call Trace:
> kernel: [ 540.869914] <TASK>
> kernel: [ 540.872136] dump_stack_lvl+0x4a/0x80
> kernel: [ 540.876012] mark_lock_irq+0x3a5/0x5a0
> kernel: [ 540.879973] ? stack_trace_save+0x55/0x80
> kernel: [ 540.884105] ? save_trace+0x66/0x200
> kernel: [ 540.887894] mark_lock+0x1f3/0x3f0
> kernel: [ 540.891417] mark_usage+0xe1/0x140
> kernel: [ 540.895060] __lock_acquire+0x3f2/0xb30
> kernel: [ 540.899020] lock_acquire+0xbf/0x2b0
> kernel: [ 540.902722] ? update_balloon_size_func+0x33/0x190
> kernel: [ 540.908073] ? lock_acquire+0xbf/0x2b0
> kernel: [ 540.912059] ? process_one_work+0x1a6/0x500
> kernel: [ 540.916388] ? process_one_work+0x1a6/0x500
> kernel: [ 540.920808] _raw_spin_lock+0x34/0x80
> kernel: [ 540.924646] ? update_balloon_size_func+0x33/0x190
> kernel: [ 540.929677] update_balloon_size_func+0x33/0x190
> kernel: [ 540.934510] ? process_one_work+0x1a6/0x500
> kernel: [ 540.939000] process_one_work+0x20f/0x500
> kernel: [ 540.943383] worker_thread+0x1e1/0x3d0
> kernel: [ 540.947391] ? __pfx_worker_thread+0x10/0x10
> kernel: [ 540.952103] kthread+0xf5/0x130
> kernel: [ 540.955392] ? __pfx_kthread+0x10/0x10
> kernel: [ 540.959290] ret_from_fork+0x31/0x50
> kernel: [ 540.963193] ? __pfx_kthread+0x10/0x10
> kernel: [ 540.967157] ret_from_fork_asm+0x1b/0x30
> kernel: [ 540.971205] </TASK>
> kernel: [ 550.008710] EXT4-fs (dm-1): mounted filesystem
> 840e25bd-f650-4819-8562-7eded85ef370 r/w with ordered data mode. Quota mode:
> none.
> systemd[1]: xt\x2dvdc.mount: Deactivated successfully.
> kernel: [ 550.033770] EXT4-fs (dm-1): unmounting filesystem
> 840e25bd-f650-4819-8562-7eded85ef370.
> root: gce-xfstests: checking for hook post-xfstests
> root: gce-xfstests: checking for hook pre-xfstests
