================================================================== BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf write to 0xffff88813564d038 of 8 bytes by task 28441 on cpu 0: relay_switch_subbuf+0x3b5/0x3c0 kernel/relay.c:711 relay_reserve include/linux/relay.h:248 [inline] __blk_add_trace+0x66f/0x740 kernel/trace/blktrace.c:275 blk_add_trace_plug+0x48/0x60 kernel/trace/blktrace.c:943 trace_block_plug include/trace/events/block.h:356 [inline] blk_mq_submit_bio+0x128d/0x1470 block/blk-mq.c:2670 __submit_bio+0x131/0x340 block/blk-core.c:851 __submit_bio_noacct_mq block/blk-core.c:926 [inline] submit_bio_noacct+0x418/0x4e0 block/blk-core.c:952 submit_bio+0x10c/0x180 iomap_dio_submit_bio fs/iomap/direct-io.c:65 [inline] iomap_dio_bio_iter+0x9ed/0xc70 fs/iomap/direct-io.c:350 __iomap_dio_rw+0x8b5/0x1070 fs/iomap/direct-io.c:589 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:679 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xa72/0x1200 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725 do_iter_write+0x192/0x5c0 fs/read_write.c:851 vfs_iter_write+0x4c/0x70 fs/read_write.c:892 iter_file_splice_write+0x43a/0x790 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0x106/0x190 fs/splice.c:979 do_sendfile+0x675/0xc40 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff88813564d038 of 8 bytes by task 1401 on cpu 1: relay_switch_subbuf+0x3b5/0x3c0 kernel/relay.c:711 relay_reserve include/linux/relay.h:248 [inline] __blk_add_trace+0x66f/0x740 kernel/trace/blktrace.c:275 blk_add_trace_plug+0x48/0x60 kernel/trace/blktrace.c:943 trace_block_plug include/trace/events/block.h:356 [inline] blk_mq_submit_bio+0x128d/0x1470 block/blk-mq.c:2670 __submit_bio+0x131/0x340 block/blk-core.c:851 __submit_bio_noacct_mq block/blk-core.c:926 [inline] submit_bio_noacct+0x418/0x4e0 block/blk-core.c:952 submit_bio+0x10c/0x180 submit_bh_wbc+0x2db/0x320 fs/buffer.c:3054 submit_bh+0x21/0x30 fs/buffer.c:3060 jbd2_journal_commit_transaction+0x1558/0x3460 fs/jbd2/commit.c:775 kjournald2+0x263/0x480 fs/jbd2/journal.c:213 kthread+0x2c7/0x2e0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 value changed: 0x0000000000000038 -> 0x0000000000000030 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1401 Comm: jbd2/sda1-8 Tainted: G W 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================