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BUG: KCSAN: data-race in dd_has_work / dd_insert_request

write to 0xffff888103593698 of 8 bytes by task 9539 on cpu 0:
 __list_add include/linux/list.h:72 [inline]
 list_add_tail include/linux/list.h:102 [inline]
 dd_insert_request+0x415/0x550 block/mq-deadline.c:758
 dd_insert_requests+0xfc/0x140 block/mq-deadline.c:777
 blk_mq_sched_insert_requests+0xc0/0x2a0 block/blk-mq-sched.c:477
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2597
 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2639
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1240
 blk_finish_plug+0x44/0x60 block/blk-core.c:1264
 __iomap_dio_rw+0xc50/0xf80 fs/iomap/direct-io.c:599
 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:681
 ext4_dio_write_iter fs/ext4/file.c:566 [inline]
 ext4_file_write_iter+0x7df/0xdf0 fs/ext4/file.c:677
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:852
 vfs_iter_write+0x4c/0x70 fs/read_write.c:893
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888103593698 of 8 bytes by task 73 on cpu 1:
 list_empty_careful include/linux/list.h:329 [inline]
 dd_has_work_for_prio block/mq-deadline.c:837 [inline]
 dd_has_work+0x188/0x260 block/mq-deadline.c:846
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:109 [inline]
 blk_mq_do_dispatch_sched+0x148/0x780 block/blk-mq-sched.c:187
 __blk_mq_sched_dispatch_requests+0x1ca/0x270
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:339
 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:1974
 blk_mq_run_work_fn+0x3d/0x50 block/blk-mq.c:2312
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

value changed: 0xffff888103593690 -> 0xffff8881035ca948

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 73 Comm: kworker/1:1H Not tainted 5.18.0-rc6-syzkaller-00148-gec7f49619d8e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_run_work_fn
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