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BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff888117459438 of 8 bytes by task 4769 on cpu 0:
 relay_switch_subbuf+0x39e/0x3b0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x66a/0x730 kernel/trace/blktrace.c:276
 blk_add_trace_bio_remap+0x165/0x180 kernel/trace/blktrace.c:1020
 trace_block_bio_remap include/trace/events/block.h:507 [inline]
 blk_partition_remap block/blk-core.c:575 [inline]
 submit_bio_noacct+0x81b/0x870 block/blk-core.c:773
 submit_bio+0x218/0x230 block/blk-core.c:890
 swap_writepage_bdev_async mm/page_io.c:372 [inline]
 __swap_writepage+0x612/0xc50 mm/page_io.c:390
 swap_writepage+0xa9/0x160 mm/page_io.c:209
 pageout mm/vmscan.c:660 [inline]
 shrink_folio_list+0x194f/0x2560 mm/vmscan.c:1341
 reclaim_folio_list+0x81/0x1e0 mm/vmscan.c:2125
 reclaim_pages+0x215/0x270 mm/vmscan.c:2161
 madvise_cold_or_pageout_pte_range+0xe43/0xec0 mm/madvise.c:550
 walk_pmd_range mm/pagewalk.c:143 [inline]
 walk_pud_range mm/pagewalk.c:221 [inline]
 walk_p4d_range mm/pagewalk.c:256 [inline]
 walk_pgd_range+0x807/0xee0 mm/pagewalk.c:293
 __walk_page_range+0xc5/0x330 mm/pagewalk.c:395
 walk_page_range+0x395/0x4e0 mm/pagewalk.c:521
 madvise_pageout_page_range mm/madvise.c:609 [inline]
 madvise_pageout mm/madvise.c:636 [inline]
 madvise_vma_behavior mm/madvise.c:1042 [inline]
 madvise_walk_vmas mm/madvise.c:1268 [inline]
 do_madvise+0x1b09/0x2610 mm/madvise.c:1464
 __do_sys_madvise mm/madvise.c:1481 [inline]
 __se_sys_madvise mm/madvise.c:1479 [inline]
 __x64_sys_madvise+0x61/0x70 mm/madvise.c:1479
 x64_sys_call+0x285d/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888117459438 of 8 bytes by task 2746 on cpu 1:
 relay_switch_subbuf+0x39e/0x3b0 kernel/relay.c:708
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x66a/0x730 kernel/trace/blktrace.c:276
 blk_add_trace_bio kernel/trace/blktrace.c:902 [inline]
 blk_add_trace_bio_queue+0x130/0x140 kernel/trace/blktrace.c:934
 trace_block_bio_queue include/trace/events/block.h:383 [inline]
 submit_bio_noacct_nocheck+0x67f/0x6e0 block/blk-core.c:720
 submit_bio_noacct+0x6b9/0x870 block/blk-core.c:848
 submit_bio+0x218/0x230 block/blk-core.c:890
 submit_bh_wbc+0x2de/0x320 fs/buffer.c:2827
 submit_bh+0x1e/0x30 fs/buffer.c:2832
 jbd2_journal_commit_transaction+0x15ee/0x33e0 fs/jbd2/commit.c:730
 kjournald2+0x243/0x430 fs/jbd2/journal.c:201
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x0000000000000040 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2746 Comm: jbd2/sda1-8 Tainted: G        W          6.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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