================================================================== BUG: KCSAN: data-race in __delayacct_blkio_end / __delayacct_blkio_start write to 0xffff888101136f08 of 8 bytes by task 20029 on cpu 1: __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 wait_on_page_bit_common+0x633/0x910 mm/filemap.c:1273 wait_on_page_bit+0x3f/0x50 mm/filemap.c:1334 wait_on_page_writeback+0x72/0x130 mm/page-writeback.c:2837 __filemap_fdatawait_range+0xdd/0x1b0 mm/filemap.c:527 filemap_fdatawait_range mm/filemap.c:554 [inline] filemap_write_and_wait_range+0x119/0x2a0 mm/filemap.c:664 __iomap_dio_rw+0x38c/0x9b0 fs/iomap/direct-io.c:489 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605 ext4_dio_read_iter fs/ext4/file.c:77 [inline] ext4_file_read_iter+0x3bd/0x420 fs/ext4/file.c:129 call_read_iter include/linux/fs.h:1881 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867 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:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 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 0xffff888101136f08 of 8 bytes by task 8 on cpu 0: 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 wake_page_function+0xd9/0x200 mm/filemap.c:1080 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:93 wake_up_page_bit+0xa4/0x190 mm/filemap.c:1113 wake_up_page mm/filemap.c:1154 [inline] end_page_writeback+0xeb/0x110 mm/filemap.c:1491 ext4_finish_bio+0x429/0x490 fs/ext4/page-io.c:146 ext4_release_io_end+0x98/0x200 fs/ext4/page-io.c:161 ext4_end_io_end fs/ext4/page-io.c:195 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:260 [inline] ext4_end_io_rsv_work+0x306/0x360 fs/ext4/page-io.c:274 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272 worker_thread+0x635/0xb90 kernel/workqueue.c:2418 kthread+0x1fa/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.10.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work ==================================================================