==================================================================
BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_request_bypass_insert

write to 0xffff88810269b810 of 8 bytes by task 230 on cpu 1:
 __list_add include/linux/list.h:70 [inline]
 list_add include/linux/list.h:86 [inline]
 blk_mq_request_bypass_insert+0x6a/0x150 block/blk-mq.c:1866
 blk_mq_sched_insert_request+0xfc/0x250 block/blk-mq-sched.c:462
 blk_mq_requeue_work+0x247/0x440 block/blk-mq.c:796
 process_one_work+0x402/0x910 kernel/workqueue.c:2297
 worker_thread+0x636/0xae0 kernel/workqueue.c:2444
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

read to 0xffff88810269b810 of 8 bytes by task 19260 on cpu 0:
 list_empty_careful include/linux/list.h:319 [inline]
 __blk_mq_sched_dispatch_requests+0x80/0x290 block/blk-mq-sched.c:305
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1487
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1564
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1617
 blk_mq_sched_insert_requests+0x12b/0x1f0 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x302/0x3d0 block/blk-mq.c:1942
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1726
 blk_finish_plug+0x44/0x60 block/blk-core.c:1743
 read_pages+0x2e9/0x540 mm/readahead.c:150
 page_cache_ra_unbounded+0x3d2/0x430 mm/readahead.c:239
 ondemand_readahead+0x58c/0x7c0
 page_cache_sync_ra+0xaf/0xe0 mm/readahead.c:580
 page_cache_sync_readahead include/linux/pagemap.h:883 [inline]
 filemap_get_pages mm/filemap.c:2545 [inline]
 filemap_read+0x3ad/0x1220 mm/filemap.c:2628
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2779
 ext4_file_read_iter+0x1db/0x290
 call_read_iter include/linux/fs.h:2157 [inline]
 generic_file_splice_read+0x24f/0x330 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff88810269b808 -> 0xffff8881028e52c8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19260 Comm: syz-executor.0 Tainted: G        W         5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================