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BUG: KCSAN: data-race in dd_has_work / deadline_remove_request

write to 0xffff888101a7ee90 of 8 bytes by task 1001 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+0x58/0x180 block/mq-deadline-main.c:198
 deadline_move_request block/mq-deadline-main.c:274 [inline]
 __dd_dispatch_request+0x3d3/0x4b0 block/mq-deadline-main.c:472
 dd_dispatch_request+0x138/0x1e0 block/mq-deadline-main.c:518
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:149 [inline]
 blk_mq_do_dispatch_sched+0x1e4/0x640 block/blk-mq-sched.c:214
 __blk_mq_sched_dispatch_requests+0x1eb/0x290 block/blk-mq-sched.c:329
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1500
 blk_mq_run_work_fn+0x3d/0x50 block/blk-mq.c:1832
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

read to 0xffff888101a7ee90 of 8 bytes by task 23405 on cpu 1:
 list_empty_careful include/linux/list.h:319 [inline]
 dd_has_work_for_prio block/mq-deadline-main.c:841 [inline]
 dd_has_work+0x187/0x260 block/mq-deadline-main.c:850
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:137 [inline]
 blk_mq_do_dispatch_sched+0x12a/0x640 block/blk-mq-sched.c:214
 __blk_mq_sched_dispatch_requests+0x1eb/0x290 block/blk-mq-sched.c:329
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1500
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1577
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1630
 blk_mq_sched_insert_requests+0x12b/0x1f0 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x2f2/0x3c0 block/blk-mq.c:1955
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1731
 blk_finish_plug+0x44/0x60 block/blk-core.c:1748
 read_pages+0x2d9/0x530 mm/readahead.c:150
 page_cache_ra_unbounded+0x15a/0x410 mm/readahead.c:210
 do_page_cache_ra mm/readahead.c:267 [inline]
 force_page_cache_ra+0x246/0x280 mm/readahead.c:299
 page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:573
 page_cache_sync_readahead include/linux/pagemap.h:884 [inline]
 filemap_get_pages mm/filemap.c:2467 [inline]
 filemap_read+0x388/0x1220 mm/filemap.c:2550
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
 blkdev_read_iter+0xb9/0xf0 fs/block_dev.c:1669
 call_read_iter include/linux/fs.h:2108 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x565/0x5d0 fs/read_write.c:496
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff888101b40648 -> 0xffff888101a7ee88

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23405 Comm: systemd-udevd Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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