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BUG: KCSAN: data-race in blk_mq_request_bypass_insert / blk_mq_run_hw_queue

write to 0xffff888101f74210 of 8 bytes by task 274 on cpu 1:
 __list_add include/linux/list.h:72 [inline]
 list_add include/linux/list.h:88 [inline]
 blk_mq_request_bypass_insert+0x6a/0x130 block/blk-mq.c:2345
 blk_mq_sched_insert_request+0xfd/0x220 block/blk-mq-sched.c:434
 blk_mq_requeue_work+0x227/0x3f0 block/blk-mq.c:1300
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

read to 0xffff888101f74210 of 8 bytes by task 3449 on cpu 0:
 list_empty_careful include/linux/list.h:321 [inline]
 blk_mq_hctx_has_pending block/blk-mq.c:100 [inline]
 blk_mq_run_hw_queue+0x19b/0x310 block/blk-mq.c:2091
 blk_mq_sched_insert_requests+0x1cc/0x2a0 block/blk-mq-sched.c:486
 blk_mq_flush_plug_list+0x5c3/0x6c0 block/blk-mq.c:2628
 blk_add_rq_to_plug+0x13f/0x3a0 block/blk-mq.c:2690
 blk_mq_submit_bio+0x8c7/0xe50 block/blk-mq.c:2831
 __submit_bio+0x151/0x350 block/blk-core.c:806
 __submit_bio_noacct_mq block/blk-core.c:881 [inline]
 submit_bio_noacct+0x475/0x4e0 block/blk-core.c:907
 submit_bio+0x10c/0x180
 ext4_io_submit+0x5e/0x80 fs/ext4/page-io.c:379
 ext4_writepages+0x94a/0x1a60 fs/ext4/inode.c:2798
 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364
 __writeback_single_inode+0x81/0x590 fs/fs-writeback.c:1618
 writeback_sb_inodes+0x677/0xdf0 fs/fs-writeback.c:1891
 __writeback_inodes_wb+0xb0/0x2b0 fs/fs-writeback.c:1961
 wb_writeback+0x280/0x650 fs/fs-writeback.c:2066
 wb_check_start_all fs/fs-writeback.c:2188 [inline]
 wb_do_writeback+0x378/0x560 fs/fs-writeback.c:2214
 wb_workfn+0xc8/0x440 fs/fs-writeback.c:2248
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0xffff888101f74208 -> 0xffff888102a2ee48

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3449 Comm: kworker/u4:57 Tainted: G        W         5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
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