syzbot

==================================================================
BUG: KCSAN: data-race in blk_mq_dispatch_rq_list / blk_mq_dispatch_rq_list

read-write to 0xffff8881008050f8 of 4 bytes by task 80 on cpu 0:
 blk_mq_update_dispatch_busy block/blk-mq.c:1993 [inline]
 blk_mq_dispatch_rq_list+0xcbe/0xfe0 block/blk-mq.c:2204
 __blk_mq_sched_dispatch_requests+0x1ba/0xd10 block/blk-mq-sched.c:301
 blk_mq_sched_dispatch_requests+0x86/0x120 block/blk-mq-sched.c:331
 blk_mq_run_work_fn+0x66/0xe0 block/blk-mq.c:2530
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff8881008050f8 of 4 bytes by task 24 on cpu 1:
 blk_mq_update_dispatch_busy block/blk-mq.c:1993 [inline]
 blk_mq_dispatch_rq_list+0xcbe/0xfe0 block/blk-mq.c:2204
 __blk_mq_sched_dispatch_requests+0x1ba/0xd10 block/blk-mq-sched.c:301
 blk_mq_sched_dispatch_requests+0x86/0x120 block/blk-mq-sched.c:331
 blk_mq_run_hw_queue+0x17e/0x220 block/blk-mq.c:2354
 blk_mq_run_hw_queues+0x180/0x250 block/blk-mq.c:2403
 blk_mq_requeue_work+0x3b9/0x3f0 block/blk-mq.c:1568
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000006 -> 0x00000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0H Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: kblockd blk_mq_requeue_work
==================================================================