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BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff88814cc18c38 of 8 bytes by interrupt on cpu 1:
 relay_switch_subbuf+0x399/0x3a0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x665/0x720 kernel/trace/blktrace.c:276
 blk_add_trace_rq kernel/trace/blktrace.c:844 [inline]
 blk_add_trace_rq_complete+0x1b3/0x1c0 kernel/trace/blktrace.c:876
 trace_block_rq_complete include/trace/events/block.h:149 [inline]
 blk_update_request+0x8f4/0x950 block/blk-mq.c:901
 scsi_end_request+0x52/0x4e0 drivers/scsi/scsi_lib.c:537
 scsi_io_completion+0x9f/0x200 drivers/scsi/scsi_lib.c:975
 scsi_finish_command+0x1bb/0x1d0 drivers/scsi/scsi.c:198
 scsi_complete+0x19a/0x1d0 drivers/scsi/scsi_lib.c:1437
 blk_complete_reqs block/blk-mq.c:1136 [inline]
 blk_done_softirq+0x73/0xa0 block/blk-mq.c:1141
 __do_softirq+0xc4/0x27b kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0x3b/0x90 kernel/softirq.c:644
 common_interrupt+0x81/0x90 arch/x86/kernel/irq.c:247
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
 kcsan_setup_watchpoint+0x3fe/0x410 kernel/kcsan/core.c:705
 hlist_add_head include/linux/list.h:1031 [inline]
 __d_instantiate+0x178/0x3c0 fs/dcache.c:1851
 d_instantiate_new+0x5c/0xf0 fs/dcache.c:1899
 ext4_add_nondir+0x16c/0x190 fs/ext4/namei.c:2798
 ext4_symlink+0x4dc/0x590 fs/ext4/namei.c:3434
 vfs_symlink+0xc2/0x1a0 fs/namei.c:4480
 do_symlinkat+0xe3/0x340 fs/namei.c:4506
 __do_sys_symlinkat fs/namei.c:4522 [inline]
 __se_sys_symlinkat fs/namei.c:4519 [inline]
 __x64_sys_symlinkat+0x62/0x70 fs/namei.c:4519
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

write to 0xffff88814cc18c38 of 8 bytes by task 2737 on cpu 0:
 relay_switch_subbuf+0x399/0x3a0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x665/0x720 kernel/trace/blktrace.c:276
 blk_add_trace_bio kernel/trace/blktrace.c:903 [inline]
 blk_add_trace_bio_queue+0x12c/0x140 kernel/trace/blktrace.c:935
 trace_block_bio_queue include/trace/events/block.h:383 [inline]
 submit_bio_noacct_nocheck+0x57d/0x5e0 block/blk-core.c:698
 submit_bio_noacct+0x67d/0x830 block/blk-core.c:825
 submit_bio+0xb7/0xc0 block/blk-core.c:858
 submit_bh_wbc+0x2ca/0x310 fs/buffer.c:2800
 submit_bh+0x1c/0x20 fs/buffer.c:2805
 jbd2_journal_commit_transaction+0x15e7/0x33b0 fs/jbd2/commit.c:731
 kjournald2+0x242/0x420 fs/jbd2/journal.c:201
 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: 0x0000000000000040 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2737 Comm: jbd2/sda1-8 Not tainted 6.8.0-rc2-syzkaller-00199-g021533194476 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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