syzbot

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BUG: KCSAN: data-race in bt_for_each / flush_end_io

write to 0xffff88813ba0e820 of 4 bytes by interrupt on cpu 0:
 flush_end_io+0x3b4/0x580 block/blk-flush.c:251
 __blk_mq_end_request+0x1fd/0x230 block/blk-mq.c:1011
 blk_mq_end_request+0x37/0x50 block/blk-mq.c:1023
 lo_complete_rq+0xca/0x170 drivers/block/loop.c:370
 blk_complete_reqs block/blk-mq.c:1099 [inline]
 blk_done_softirq+0x92/0xc0 block/blk-mq.c:1104
 __do_softirq+0xf2/0x2c7 kernel/softirq.c:571
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:934
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

read to 0xffff88813ba0e820 of 4 bytes by task 41 on cpu 1:
 blk_mq_find_and_get_req block/blk-mq-tag.c:253 [inline]
 bt_iter block/blk-mq-tag.c:280 [inline]
 __sbitmap_for_each_set include/linux/sbitmap.h:275 [inline]
 sbitmap_for_each_set include/linux/sbitmap.h:296 [inline]
 bt_for_each+0x2b0/0x4b0 block/blk-mq-tag.c:317
 blk_mq_queue_tag_busy_iter+0x1a9/0x310 block/blk-mq-tag.c:526
 blk_mq_timeout_work+0xa7/0x2a0 block/blk-mq.c:1601
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

value changed: 0x0000002b -> 0xffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 41 Comm: kworker/1:1H Tainted: G        W          6.1.0-rc3-syzkaller-00035-gf526d6a82242-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Workqueue: kblockd blk_mq_timeout_work
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