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BUG: KCSAN: data-race in dd_has_work / deadline_remove_request

write to 0xffff88812ac04428 of 8 bytes by task 3222 on cpu 1:
 __list_del include/linux/list.h:112 [inline]
 __list_del_entry include/linux/list.h:135 [inline]
 list_del_init include/linux/list.h:204 [inline]
 deadline_remove_request+0x6a/0x180 block/mq-deadline.c:113
 deadline_move_request block/mq-deadline.c:176 [inline]
 __dd_dispatch_request block/mq-deadline.c:365 [inline]
 dd_dispatch_request+0x6d2/0x740 block/mq-deadline.c:387
 blk_mq_do_dispatch_sched+0x15f/0x2b0 block/blk-mq-sched.c:114
 __blk_mq_sched_dispatch_requests+0x20f/0x2b0 block/blk-mq-sched.c:245
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:276
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1418
 __blk_mq_delay_run_hw_queue+0x199/0x340 block/blk-mq.c:1495
 blk_mq_run_hw_queue+0x22e/0x260 block/blk-mq.c:1548
 blk_mq_run_hw_queues block/blk-mq.c:1566 [inline]
 blk_mq_requeue_work+0x433/0x4a0 block/blk-mq.c:774
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

read to 0xffff88812ac04428 of 8 bytes by task 16532 on cpu 0:
 list_empty_careful include/linux/list.h:301 [inline]
 dd_has_work+0xc7/0xe0 block/mq-deadline.c:584
 blk_mq_do_dispatch_sched+0xa8/0x2b0 block/blk-mq-sched.c:103
 __blk_mq_sched_dispatch_requests+0x20f/0x2b0 block/blk-mq-sched.c:245
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:276
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1418
 __blk_mq_delay_run_hw_queue+0x199/0x340 block/blk-mq.c:1495
 blk_mq_run_hw_queue+0x22e/0x260 block/blk-mq.c:1548
 blk_mq_sched_insert_requests+0x14d/0x200 block/blk-mq-sched.c:530
 blk_mq_flush_plug_list+0x2f5/0x420 block/blk-mq.c:1817
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1859
 blk_finish_plug+0x44/0x60 block/blk-core.c:1876
 iomap_dio_rw+0x61b/0x8c0 fs/iomap/direct-io.c:523
 ext4_dio_write_iter fs/ext4/file.c:545 [inline]
 ext4_file_write_iter+0xda4/0x1010 fs/ext4/file.c:653
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x321/0x3c0 fs/read_write.c:694
 do_iter_write+0x10e/0x470 fs/read_write.c:999
 vfs_iter_write+0x4c/0x70 fs/read_write.c:1040
 iter_file_splice_write+0x41a/0x770 fs/splice.c:750
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x95/0x160 fs/splice.c:1016
 splice_direct_to_actor+0x365/0x660 fs/splice.c:971
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x562/0xb10 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1568
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16532 Comm: syz-executor.5 Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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