================================================================== BUG: KCSAN: data-race in balance_dirty_pages / percpu_counter_add_batch write to 0xffff8881208c8c68 of 8 bytes by task 2633 on cpu 0: percpu_counter_add_batch+0xca/0x150 lib/percpu_counter.c:91 __add_wb_stat include/linux/backing-dev.h:73 [inline] dec_wb_stat include/linux/backing-dev.h:83 [inline] clear_page_dirty_for_io+0x4c4/0x590 mm/page-writeback.c:2704 mpage_submit_page+0x6d/0x1a0 fs/ext4/inode.c:2202 mpage_map_and_submit_buffers+0x331/0x520 fs/ext4/inode.c:2422 mpage_map_and_submit_extent fs/ext4/inode.c:2556 [inline] ext4_writepages+0x1458/0x2300 fs/ext4/inode.c:2869 do_writepages+0x6b/0x170 mm/page-writeback.c:2344 __writeback_single_inode+0xaf/0x8e0 fs/fs-writeback.c:1452 writeback_sb_inodes+0x4ba/0xa50 fs/fs-writeback.c:1716 __writeback_inodes_wb+0xe8/0x1b0 fs/fs-writeback.c:1785 wb_writeback+0x557/0x6a0 fs/fs-writeback.c:1894 wb_check_background_flush fs/fs-writeback.c:1962 [inline] wb_do_writeback fs/fs-writeback.c:2050 [inline] wb_workfn+0x696/0x970 fs/fs-writeback.c:2078 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 read to 0xffff8881208c8c68 of 8 bytes by task 15657 on cpu 1: wb_stat include/linux/backing-dev.h:88 [inline] wb_dirty_limits mm/page-writeback.c:1549 [inline] balance_dirty_pages+0x1237/0x1ba0 mm/page-writeback.c:1693 balance_dirty_pages_ratelimited+0x752/0xb40 mm/page-writeback.c:1913 generic_perform_write+0x22d/0x320 mm/filemap.c:3341 __generic_file_write_iter+0x251/0x380 mm/filemap.c:3434 ext4_file_write_iter+0x1bd/0xa00 fs/ext4/file.c:268 call_write_iter include/linux/fs.h:1895 [inline] new_sync_write+0x388/0x4a0 fs/read_write.c:483 __vfs_write+0xb1/0xc0 fs/read_write.c:496 vfs_write fs/read_write.c:558 [inline] vfs_write+0x18a/0x390 fs/read_write.c:542 ksys_write+0xd5/0x1b0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x4c/0x60 fs/read_write.c:620 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 15657 Comm: syz-executor.4 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================