================================================================== BUG: KCSAN: data-race in ext4_ext_insert_extent / ext4_mark_iloc_dirty write to 0xffff888128b0899c of 2 bytes by task 2140 on cpu 0: ext4_ext_insert_extent+0x1408/0x25c0 fs/ext4/extents.c:2012 ext4_ext_map_blocks+0xc5c/0x2330 fs/ext4/extents.c:4486 ext4_map_blocks+0x23a/0xfa0 fs/ext4/inode.c:640 mpage_map_one_extent fs/ext4/inode.c:2468 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2517 [inline] ext4_writepages+0x136e/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 0xffff888128b0899c of 4 bytes by task 5872 on cpu 1: ext4_do_update_inode fs/ext4/inode.c:5304 [inline] ext4_mark_iloc_dirty+0xa32/0x1580 fs/ext4/inode.c:5876 ext4_mark_inode_dirty+0xe9/0x420 fs/ext4/inode.c:6055 ext4_dirty_inode+0x86/0xb0 fs/ext4/inode.c:6086 __mark_inode_dirty+0x5d4/0x940 fs/fs-writeback.c:2258 mark_inode_dirty include/linux/fs.h:2165 [inline] generic_write_end+0x1b7/0x1f0 fs/buffer.c:2159 ext4_da_write_end+0x158/0x620 fs/ext4/inode.c:3189 generic_perform_write+0x1d3/0x320 mm/filemap.c:3316 __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: 5872 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================