==================================================================
BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff888147a97238 of 8 bytes by interrupt 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_rq kernel/trace/blktrace.c:836 [inline]
 blk_add_trace_rq_complete+0x102/0x110 kernel/trace/blktrace.c:869
 trace_block_rq_complete include/trace/events/block.h:115 [inline]
 blk_update_request+0x950/0x990 block/blk-mq.c:715
 scsi_end_request+0x4b/0x440 drivers/scsi/scsi_lib.c:543
 scsi_io_completion+0xd0/0x10c0 drivers/scsi/scsi_lib.c:939
 scsi_finish_command+0x1c0/0x1d0 drivers/scsi/scsi.c:199
 scsi_complete+0x1a5/0x1e0 drivers/scsi/scsi_lib.c:1441
 blk_complete_reqs block/blk-mq.c:892 [inline]
 blk_done_softirq+0x92/0xc0 block/blk-mq.c:897
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 __irq_exit_rcu kernel/softirq.c:637 [inline]
 irq_exit_rcu+0x37/0x70 kernel/softirq.c:649
 common_interrupt+0x9f/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40
 kcsan_setup_watchpoint+0x94/0x420 kernel/kcsan/core.c:443
 crypto_tfm_alg_alignmask include/linux/crypto.h:690 [inline]
 crypto_shash_alignmask include/crypto/hash.h:750 [inline]
 crypto_shash_update+0x5a/0x1a0 crypto/shash.c:126
 ext4_chksum fs/ext4/ext4.h:2453 [inline]
 ext4_inode_bitmap_csum_set+0xc9/0x190 fs/ext4/bitmap.c:51
 __ext4_new_inode+0x1730/0x2480 fs/ext4/ialloc.c:1226
 ext4_symlink+0x23b/0x5d0 fs/ext4/namei.c:3293
 vfs_symlink+0x241/0x330 fs/namei.c:4248
 do_symlinkat+0x104/0x380 fs/namei.c:4277
 __do_sys_symlink fs/namei.c:4299 [inline]
 __se_sys_symlink fs/namei.c:4297 [inline]
 __x64_sys_symlink+0x52/0x60 fs/namei.c:4297
 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 0xffff888147a97238 of 8 bytes by task 12918 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_bio kernel/trace/blktrace.c:896 [inline]
 blk_add_trace_bio_queue+0xb1/0xc0 kernel/trace/blktrace.c:928
 trace_block_bio_queue include/trace/events/block.h:332 [inline]
 submit_bio_checks+0x8a5/0x8e0 block/blk-core.c:821
 blk_mq_get_request block/blk-mq.c:2589 [inline]
 blk_mq_submit_bio+0x2e1/0x1470 block/blk-mq.c:2633
 __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+0x7eb/0xdc0 fs/ext4/file.c:679
 call_write_iter include/linux/fs.h:2162 [inline]
 aio_write+0x2dc/0x3c0 fs/aio.c:1578
 io_submit_one+0x8c6/0x1410 fs/aio.c:1997
 __do_sys_io_submit fs/aio.c:2056 [inline]
 __se_sys_io_submit+0x105/0x280 fs/aio.c:2026
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:2026
 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

value changed: 0x0000000000000040 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12918 Comm: syz-executor.4 Not tainted 5.16.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================