On Mon, Apr 10, 2023 at 08:20:22PM +0800, Hillf Danton wrote: > On 07 Apr 2023 10:04:49 -0700 > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 7e364e56293b Linux 6.3-rc5 > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=13241195c80000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=e3b9dc6616d797bb > > dashboard link: https://syzkaller.appspot.com/bug?extid=5ed016962f5137a09c7c > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > userspace arch: i386 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+5ed016962f5137a09c7c@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ------------[ cut here ]------------ > > WARNING: CPU: 1 PID: 102 at kernel/workqueue.c:1445 __queue_work+0xd44/0x1120 kernel/workqueue.c:1444 > > Modules linked in: > > CPU: 1 PID: 102 Comm: kswapd0 Not tainted 6.3.0-rc5-syzkaller #0 > > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 > > RIP: 0010:__queue_work+0xd44/0x1120 kernel/workqueue.c:1444 Gross. I just got one of these splats too, in: __queue_work+0x3a2/0x4a0 call_timer_fn+0x24/0x120 __run_timers.part.0+0x170/0x280 run_timer_softirq+0x31/0x60 __do_softirq+0xf6/0x2fd irq_exit_rcu+0xc5/0x110 sysvec_apic_timer_interrupt+0x8e/0xc0 I guess someone might have done: Thread 0: xfs_inodegc_queue_all(mp); Thread 1: <add inodegc work> Thread 1: mod_delayed_work_on(cpu, mp->m_inodegc_wq, &gc->work, <nonzero>); Thread 0: drain_workqueue(mp->m_inodegc_wq); <Timer fires, splats, everyone halts> But I can't really tell, the VM froze. Any suggestions on how to fix this? --D > > Code: e0 07 83 c0 03 38 d0 7c 09 84 d2 74 05 e8 74 0c 81 00 8b 5b 2c 31 ff 83 e3 20 89 de e8 c5 fb 2f 00 85 db 75 42 e8 6c ff 2f 00 <0f> 0b e9 3c f9 ff ff e8 60 ff 2f 00 0f 0b e9 ce f8 ff ff e8 54 ff > > RSP: 0000:ffffc90000ce7638 EFLAGS: 00010093 > > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > > RDX: ffff888015f73a80 RSI: ffffffff8152d854 RDI: 0000000000000005 > > RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000000 R12: ffffe8ffffb03348 > > R13: ffff888078462000 R14: ffffe8ffffb03390 R15: ffff888078462000 > > FS: 0000000000000000(0000) GS:ffff88802ca80000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000000000cfa5bb CR3: 0000000025fde000 CR4: 0000000000150ee0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > <TASK> > > __queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1672 > > mod_delayed_work_on+0xe1/0x220 kernel/workqueue.c:1746 > > xfs_inodegc_shrinker_scan fs/xfs/xfs_icache.c:2212 [inline] > > xfs_inodegc_shrinker_scan+0x250/0x4f0 fs/xfs/xfs_icache.c:2191 > > do_shrink_slab+0x428/0xaa0 mm/vmscan.c:853 > > shrink_slab+0x175/0x660 mm/vmscan.c:1013 > > shrink_one+0x502/0x810 mm/vmscan.c:5343 > > shrink_many mm/vmscan.c:5394 [inline] > > lru_gen_shrink_node mm/vmscan.c:5511 [inline] > > shrink_node+0x2064/0x35f0 mm/vmscan.c:6459 > > kswapd_shrink_node mm/vmscan.c:7262 [inline] > > balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452 > > kswapd+0x677/0xd60 mm/vmscan.c:7712 > > kthread+0x2e8/0x3a0 kernel/kthread.c:376 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 > > </TASK> > > Looks like a valid race. > > xfs_inodegc_shrinker_scan() xfs_inodegc_stop() > --- --- > if (!xfs_is_inodegc_enabled(mp)) > return SHRINK_STOP; > if (!xfs_clear_inodegc_enabled(mp)) > return; > xfs_inodegc_queue_all(mp); > drain_workqueue(mp->m_inodegc_wq); > wq->flags |= __WQ_DRAINING; > mod_delayed_work_on()
