syzbot

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BUG: KCSAN: data-race in blk_mq_sched_dispatch_requests / blk_mq_sched_dispatch_requests

read-write to 0xffff888100fe1350 of 8 bytes by task 5363 on cpu 0:
 blk_mq_sched_dispatch_requests+0x84/0x100 block/blk-mq-sched.c:327
 blk_mq_run_hw_queue+0x298/0x4c0 block/blk-mq.c:2265
 blk_mq_flush_plug_list+0x7a7/0xdb0 block/blk-mq.c:2813
 __blk_flush_plug+0x210/0x260 block/blk-core.c:1166
 blk_finish_plug+0x47/0x60 block/blk-core.c:1190
 __iomap_dio_rw+0xc69/0x1090 fs/iomap/direct-io.c:667
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:748
 ext4_dio_read_iter fs/ext4/file.c:94 [inline]
 ext4_file_read_iter+0x21c/0x2a0 fs/ext4/file.c:145
 call_read_iter include/linux/fs.h:2079 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x288/0x650 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read-write to 0xffff888100fe1350 of 8 bytes by task 44 on cpu 1:
 blk_mq_sched_dispatch_requests+0x84/0x100 block/blk-mq-sched.c:327
 blk_mq_run_work_fn+0x65/0xe0 block/blk-mq.c:2435
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x00000000000012ee -> 0x00000000000012ef

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 44 Comm: kworker/1:1H Not tainted 6.7.0-syzkaller-11889-g86c4d58a99ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: kblockd blk_mq_run_work_fn
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