On Wed, 23 Mar 2022 09:13:08 +0800, Ming Lei wrote:
> blkg_free() may be called in atomic context, either spin lock is held,
> or run in rcu callback. Meantime either request queue's release handler
> or ->pd_free_fn can sleep.
>
> Fix the issue by scheduling work function for freeing blkcg_gq instance.
>
> [ 148.553894] BUG: sleeping function called from invalid context at block/blk-sysfs.c:767
> [ 148.557381] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/13
> [ 148.560741] preempt_count: 101, expected: 0
> [ 148.562577] RCU nest depth: 0, expected: 0
> [ 148.564379] 1 lock held by swapper/13/0:
> [ 148.566127] #0: ffffffff82615f80 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x0/0x1b
> [ 148.569640] Preemption disabled at:
> [ 148.569642] [<ffffffff8123f9c3>] ___slab_alloc+0x554/0x661
> [ 148.573559] CPU: 13 PID: 0 Comm: swapper/13 Kdump: loaded Not tainted 5.17.0_up+ #110
> [ 148.576834] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-1.fc33 04/01/2014
> [ 148.579768] Call Trace:
> [ 148.580567] <IRQ>
> [ 148.581262] dump_stack_lvl+0x56/0x7c
> [ 148.582367] ? ___slab_alloc+0x554/0x661
> [ 148.583526] __might_resched+0x1af/0x1c8
> [ 148.584678] blk_release_queue+0x24/0x109
> [ 148.585861] kobject_cleanup+0xc9/0xfe
> [ 148.586979] blkg_free+0x46/0x63
> [ 148.587962] rcu_do_batch+0x1c5/0x3db
> [ 148.589057] rcu_core+0x14a/0x184
> [ 148.590065] __do_softirq+0x14d/0x2c7
> [ 148.591167] __irq_exit_rcu+0x7a/0xd4
> [ 148.592264] sysvec_apic_timer_interrupt+0x82/0xa5
> [ 148.593649] </IRQ>
> [ 148.594354] <TASK>
> [ 148.595058] asm_sysvec_apic_timer_interrupt+0x12/0x20
>
> [...]
Applied, thanks!
[1/1] block: avoid to call blkg_free() in atomic context
commit: d578c770c85233af592e54537f93f3831bde7e9a
Best regards,
--
Jens Axboe
