==================================================================
BUG: KCSAN: data-race in enqueue_timer / wbt_wait

read to 0xffff88812b052f98 of 8 bytes by task 922 on cpu 0:
 blk_stat_is_active block/blk-stat.h:131 [inline]
 wbt_wait+0x177/0x250 block/blk-wbt.c:593
 __rq_qos_throttle+0x47/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_make_request+0x29c/0xf60 block/blk-mq.c:1932
 generic_make_request block/blk-core.c:1066 [inline]
 generic_make_request+0x196/0x700 block/blk-core.c:1008
 submit_bio+0x96/0x3c0 block/blk-core.c:1192
 ext4_io_submit+0xdf/0x110 fs/ext4/page-io.c:384
 io_submit_add_bh fs/ext4/page-io.c:425 [inline]
 ext4_bio_write_page+0x480/0xb4e fs/ext4/page-io.c:543
 mpage_submit_page+0xe4/0x1a0 fs/ext4/inode.c:2075
 mpage_process_page_bufs+0x3e5/0x400 fs/ext4/inode.c:2189
 mpage_prepare_extent_to_map+0x48b/0x760 fs/ext4/inode.c:2596
 ext4_writepages+0x974/0x2500 fs/ext4/inode.c:2724
 do_writepages+0x6b/0x170 mm/page-writeback.c:2344
 __writeback_single_inode+0xaf/0x8e0 fs/fs-writeback.c:1452
 writeback_sb_inodes+0x4ba/0xa50 fs/fs-writeback.c:1716
 wb_writeback+0x1f9/0x6a0 fs/fs-writeback.c:1892
 wb_do_writeback fs/fs-writeback.c:2037 [inline]
 wb_workfn+0x22e/0x970 fs/fs-writeback.c:2078
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff88812b052f98 of 8 bytes by task 22555 on cpu 1:
 hlist_add_head include/linux/list.h:787 [inline]
 enqueue_timer+0x6c/0x210 kernel/time/timer.c:540
 __internal_add_timer+0x4f/0x60 kernel/time/timer.c:553
 internal_add_timer kernel/time/timer.c:595 [inline]
 __mod_timer kernel/time/timer.c:1053 [inline]
 mod_timer kernel/time/timer.c:1100 [inline]
 add_timer+0x250/0x550 kernel/time/timer.c:1136
 __queue_delayed_work+0x13b/0x1d0 kernel/workqueue.c:1644
 queue_delayed_work_on+0xf3/0x110 kernel/workqueue.c:1669
 queue_delayed_work include/linux/workqueue.h:509 [inline]
 schedule_delayed_work include/linux/workqueue.h:610 [inline]
 nsim_dev_trap_report_work+0x581/0x5a0 drivers/net/netdevsim/dev.c:416
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22555 Comm: kworker/1:6 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
==================================================================