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BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff888140c42038 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:864
 scsi_end_request+0x52/0x470 drivers/scsi/scsi_lib.c:541
 scsi_io_completion+0x95/0x1f0 drivers/scsi/scsi_lib.c:979
 scsi_finish_command+0x1b7/0x1c0 drivers/scsi/scsi.c:198
 scsi_complete+0x19e/0x1d0 drivers/scsi/scsi_lib.c:1446
 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
 __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
 refill_stock+0xf9/0x130
 obj_cgroup_uncharge_pages+0x75/0x130 mm/memcontrol.c:3074
 __memcg_kmem_uncharge_page+0x4f/0x100 mm/memcontrol.c:3147
 memcg_kmem_uncharge_page include/linux/memcontrol.h:1761 [inline]
 exit_task_stack_account+0x69/0x90 kernel/fork.c:516
 do_exit+0x10bc/0x1740 kernel/exit.c:862
 do_group_exit+0xfe/0x140 kernel/exit.c:950
 get_signal+0xb40/0xc60 kernel/signal.c:2858
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:168
 exit_to_user_mode_prepare kernel/entry/common.c:203 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:296
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff888140c42038 of 8 bytes by task 28010 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_bio kernel/trace/blktrace.c:907 [inline]
 blk_add_trace_getrq+0x12e/0x140 kernel/trace/blktrace.c:944
 trace_block_getrq include/trace/events/block.h:366 [inline]
 blk_mq_submit_bio+0xe2d/0xe90 block/blk-mq.c:2907
 __submit_bio block/blk-core.c:591 [inline]
 __submit_bio_noacct_mq block/blk-core.c:668 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:685
 submit_bio_noacct+0x6a5/0x810 block/blk-core.c:791
 submit_bio+0xfb/0x110 block/blk-core.c:827
 iomap_dio_submit_bio fs/iomap/direct-io.c:77 [inline]
 iomap_dio_bio_iter+0xa4d/0xc00 fs/iomap/direct-io.c:361
 __iomap_dio_rw+0x981/0x1000 fs/iomap/direct-io.c:602
 iomap_dio_rw+0x3c/0x80 fs/iomap/direct-io.c:690
 ext4_dio_write_iter fs/ext4/file.c:587 [inline]
 ext4_file_write_iter+0xa27/0x1170 fs/ext4/file.c:698
 call_write_iter include/linux/fs.h:2191 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x468/0x760 fs/read_write.c:584
 ksys_write+0xe8/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:646
 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: 28010 Comm: syz-executor.1 Not tainted 6.1.0-rc3-syzkaller-00299-g2f5065a0bc9d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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