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BUG: KCSAN: data-race in blk_stat_add / enqueue_timer

read to 0xffff88821aa79298 of 8 bytes by interrupt on cpu 0:
 blk_stat_is_active block/blk-stat.h:131 [inline]
 blk_stat_add+0x103/0x2c0 block/blk-stat.c:66
 __blk_mq_end_request block/blk-mq.c:527 [inline]
 blk_mq_end_request+0x256/0x2b0 block/blk-mq.c:548
 lo_complete_rq+0x136/0x1a0 drivers/block/loop.c:487
 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff88821aa79298 of 8 bytes by task 16273 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]
 fsnotify_put_mark+0x29c/0x3f0 fs/notify/mark.c:276
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:790 [inline]
 __se_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:762 [inline]
 __x64_sys_inotify_rm_watch+0xd7/0x130 fs/notify/inotify/inotify_user.c:762
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16273 Comm: udevd Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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