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BUG: KCSAN: data-race in __delayacct_blkio_end / __delayacct_blkio_start

write to 0xffff888100c82f08 of 8 bytes by task 12282 on cpu 0:
 __delayacct_blkio_start+0x35/0x40 kernel/delayacct.c:61
 delayacct_blkio_start include/linux/delayacct.h:119 [inline]
 __schedule+0x18c/0x550 kernel/sched/core.c:4485
 schedule+0x7f/0xb0 kernel/sched/core.c:4601
 io_schedule+0x3b/0x50 kernel/sched/core.c:6295
 bit_wait_io+0x8/0x40 kernel/sched/wait_bit.c:209
 __wait_on_bit kernel/sched/wait_bit.c:49 [inline]
 out_of_line_wait_on_bit+0xb6/0x110 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 __wait_on_buffer fs/buffer.c:122 [inline]
 wait_on_buffer include/linux/buffer_head.h:354 [inline]
 __sync_dirty_buffer+0x196/0x1d0 fs/buffer.c:3156
 sync_dirty_buffer+0x16/0x20 fs/buffer.c:3168
 ext4_write_inode+0x28b/0x390 fs/ext4/inode.c:5228
 write_inode+0x8c/0x1f0 fs/fs-writeback.c:1320
 __writeback_single_inode+0x304/0x560 fs/fs-writeback.c:1516
 writeback_single_inode+0x126/0x580 fs/fs-writeback.c:1570
 sync_inode fs/fs-writeback.c:2606 [inline]
 sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2626
 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
 ext4_sync_file+0x359/0x6c0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2723 [inline]
 ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1887 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 fs/splice.c:686
 ovl_splice_write+0x130/0x360 fs/overlayfs/file.c:434
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x574/0xb70 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1312 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888100c82f08 of 8 bytes by task 12280 on cpu 1:
 delayacct_end kernel/delayacct.c:48 [inline]
 __delayacct_blkio_end+0x70/0xf0 kernel/delayacct.c:82
 delayacct_blkio_end include/linux/delayacct.h:125 [inline]
 try_to_wake_up+0x107/0x470 kernel/sched/core.c:2892
 autoremove_wake_function+0xc/0x50 kernel/sched/wait.c:389
 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:93
 __wake_up_common_lock kernel/sched/wait.c:123 [inline]
 __wake_up+0x80/0xc0 kernel/sched/wait.c:142
 __wake_up_bit kernel/sched/wait_bit.c:126 [inline]
 wake_up_bit+0x72/0x90 kernel/sched/wait_bit.c:149
 __sync_dirty_buffer+0xfa/0x1d0 arch/x86/include/asm/bitops.h:75
 sync_dirty_buffer+0x16/0x20 fs/buffer.c:3168
 ext4_write_inode+0x28b/0x390 fs/ext4/inode.c:5228
 write_inode+0x8c/0x1f0 fs/fs-writeback.c:1320
 __writeback_single_inode+0x304/0x560 fs/fs-writeback.c:1516
 writeback_single_inode+0x126/0x580 fs/fs-writeback.c:1570
 sync_inode fs/fs-writeback.c:2606 [inline]
 sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2626
 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
 ext4_sync_file+0x359/0x6c0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2723 [inline]
 ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1887 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 fs/splice.c:686
 ovl_splice_write+0x130/0x360 fs/overlayfs/file.c:434
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x574/0xb70 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1312 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12280 Comm: syz-executor.1 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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