==================================================================
BUG: KCSAN: data-race in dd_has_work / deadline_remove_request

write to 0xffff888103717f98 of 8 bytes by task 31458 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+0x690/0x730 block/mq-deadline.c:387
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:146 [inline]
 blk_mq_do_dispatch_sched+0x1df/0x610 block/blk-mq-sched.c:199
 __blk_mq_sched_dispatch_requests+0x1fd/0x2a0 block/blk-mq-sched.c:310
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:341
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1532
 __blk_mq_delay_run_hw_queue+0x17d/0x330 block/blk-mq.c:1609
 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1662
 blk_mq_sched_insert_requests+0x144/0x210 block/blk-mq-sched.c:501
 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1932
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1760
 blk_finish_plug+0x44/0x60 block/blk-core.c:1777
 __iomap_dio_rw+0x60f/0x9b0 fs/iomap/direct-io.c:539
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x3bd/0x420 fs/ext4/file.c:129
 call_read_iter include/linux/fs.h:1897 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5db/0xca0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888103717f98 of 8 bytes by task 31476 on cpu 0:
 list_empty_careful include/linux/list.h:319 [inline]
 dd_has_work+0xc3/0x110 block/mq-deadline.c:589
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:135 [inline]
 blk_mq_do_dispatch_sched+0x138/0x610 block/blk-mq-sched.c:199
 __blk_mq_sched_dispatch_requests+0x1fd/0x2a0 block/blk-mq-sched.c:310
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:341
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1532
 __blk_mq_delay_run_hw_queue+0x17d/0x330 block/blk-mq.c:1609
 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1662
 blk_mq_sched_insert_requests+0x144/0x210 block/blk-mq-sched.c:501
 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1932
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1760
 blk_finish_plug+0x44/0x60 block/blk-core.c:1777
 __iomap_dio_rw+0x60f/0x9b0 fs/iomap/direct-io.c:539
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x3bd/0x420 fs/ext4/file.c:129
 call_read_iter include/linux/fs.h:1897 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5db/0xca0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31476 Comm: syz-executor.3 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================