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BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff88813d1d1238 of 8 bytes by interrupt on cpu 1:
 relay_switch_subbuf+0x39d/0x3b0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x6a7/0x700 kernel/trace/blktrace.c:276
 blk_add_trace_rq kernel/trace/blktrace.c:848 [inline]
 blk_add_trace_rq_complete+0x1af/0x1c0 kernel/trace/blktrace.c:880
 trace_block_rq_complete include/trace/events/block.h:147 [inline]
 blk_update_request+0x807/0x850 block/blk-mq.c:896
 scsi_end_request+0x52/0x470 drivers/scsi/scsi_lib.c:539
 scsi_io_completion+0x95/0x1f0 drivers/scsi/scsi_lib.c:977
 scsi_finish_command+0x1b7/0x1c0 drivers/scsi/scsi.c:198
 scsi_complete+0x19e/0x1d0 drivers/scsi/scsi_lib.c:1441
 blk_complete_reqs block/blk-mq.c:1131 [inline]
 blk_done_softirq+0x92/0xc0 block/blk-mq.c:1136
 __do_softirq+0xf2/0x2c7 kernel/softirq.c:571
 __irq_exit_rcu kernel/softirq.c:650 [inline]
 irq_exit_rcu+0x41/0x70 kernel/softirq.c:662
 common_interrupt+0x9f/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:570 [inline]
 acpi_idle_enter+0x283/0x340 drivers/acpi/processor_idle.c:707
 cpuidle_enter_state+0x2de/0x960 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x1a7/0x250 kernel/sched/idle.c:303
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400
 start_secondary+0x78/0x80 arch/x86/kernel/smpboot.c:264
 secondary_startup_64_no_verify+0xcf/0xdb

write to 0xffff88813d1d1238 of 8 bytes by task 21864 on cpu 0:
 relay_switch_subbuf+0x39d/0x3b0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x6a7/0x700 kernel/trace/blktrace.c:276
 blk_add_trace_rq kernel/trace/blktrace.c:848 [inline]
 blk_add_trace_rq_insert+0x1b2/0x1c0 kernel/trace/blktrace.c:855
 trace_block_rq_insert include/trace/events/block.h:213 [inline]
 dd_insert_request+0x30b/0x570 block/mq-deadline.c:802
 dd_insert_requests+0xfc/0x140 block/mq-deadline.c:839
 blk_mq_sched_insert_requests+0xc0/0x300 block/blk-mq-sched.c:477
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2758
 blk_mq_flush_plug_list+0x38a/0x3e0 block/blk-mq.c:2800
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1137
 blk_finish_plug+0x44/0x60 block/blk-core.c:1161
 __iomap_dio_rw+0xd27/0x1000 fs/iomap/direct-io.c:609
 iomap_dio_rw+0x3c/0x80 fs/iomap/direct-io.c:689
 ext4_dio_write_iter fs/ext4/file.c:587 [inline]
 ext4_file_write_iter+0xa36/0x11b0 fs/ext4/file.c:698
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000038 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21864 Comm: syz-executor.0 Not tainted 6.2.0-rc4-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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