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BUG: KCSAN: data-race in dd_has_work / deadline_remove_request

write to 0xffff8881009f7728 of 8 bytes by task 10155 on cpu 0:
 __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:115
 deadline_move_request block/mq-deadline.c:178 [inline]
 __dd_dispatch_request block/mq-deadline.c:367 [inline]
 dd_dispatch_request+0x34f/0x3d0 block/mq-deadline.c:389
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:149 [inline]
 blk_mq_do_dispatch_sched+0x1f1/0x660 block/blk-mq-sched.c:204
 __blk_mq_sched_dispatch_requests+0x21e/0x2c0 block/blk-mq-sched.c:320
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:351
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1499
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1576
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1629
 blk_mq_sched_insert_requests+0x13f/0x200 block/blk-mq-sched.c:503
 blk_mq_flush_plug_list+0x2f5/0x3c0 block/blk-mq.c:1954
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1747
 blk_finish_plug+0x44/0x60 block/blk-core.c:1764
 __iomap_dio_rw+0x780/0xad0 fs/iomap/direct-io.c:583
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa04/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x40a/0x750 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+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881009f7728 of 8 bytes by task 10157 on cpu 1:
 list_empty_careful include/linux/list.h:319 [inline]
 dd_has_work+0xd3/0xe0 block/mq-deadline.c:582
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:137 [inline]
 blk_mq_do_dispatch_sched+0x138/0x660 block/blk-mq-sched.c:204
 __blk_mq_sched_dispatch_requests+0x21e/0x2c0 block/blk-mq-sched.c:320
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:351
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1499
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1576
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1629
 blk_mq_sched_insert_requests+0x13f/0x200 block/blk-mq-sched.c:503
 blk_mq_flush_plug_list+0x2f5/0x3c0 block/blk-mq.c:1954
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1747
 blk_finish_plug+0x44/0x60 block/blk-core.c:1764
 __iomap_dio_rw+0x780/0xad0 fs/iomap/direct-io.c:583
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa04/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x40a/0x750 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+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff8881025d0f48 -> 0xffff8881009f7720

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10157 Comm: syz-executor.3 Not tainted 5.13.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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