================================================================== BUG: KCSAN: data-race in ext4_write_end / mpage_process_page_bufs write to 0xffff88800aeac670 of 8 bytes by task 8085 on cpu 0: i_size_write include/linux/fs.h:870 [inline] ext4_update_inode_size fs/ext4/ext4.h:3285 [inline] ext4_write_end+0x1fe/0xa00 fs/ext4/inode.c:1310 ext4_da_write_end+0x93/0x760 fs/ext4/inode.c:3080 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3419 ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4b0 fs/read_write.c:866 vfs_writev fs/read_write.c:939 [inline] do_pwritev+0x20d/0x400 fs/read_write.c:1036 __do_sys_pwritev fs/read_write.c:1083 [inline] __se_sys_pwritev fs/read_write.c:1078 [inline] __x64_sys_pwritev+0x54/0x60 fs/read_write.c:1078 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88800aeac670 of 8 bytes by task 24 on cpu 1: i_size_read include/linux/fs.h:848 [inline] mpage_process_page_bufs+0x34/0x5d0 fs/ext4/inode.c:2193 mpage_prepare_extent_to_map+0x4d6/0x630 fs/ext4/inode.c:2627 ext4_writepages+0x97b/0x1e50 fs/ext4/inode.c:2799 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __writeback_single_inode+0x84/0x560 fs/fs-writeback.c:1461 writeback_sb_inodes+0x6a0/0x1020 fs/fs-writeback.c:1721 wb_writeback+0x27d/0x660 fs/fs-writeback.c:1894 wb_do_writeback+0x101/0x5d0 fs/fs-writeback.c:2039 wb_workfn+0xb8/0x410 fs/fs-writeback.c:2080 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x635/0xb90 kernel/workqueue.c:2421 kthread+0x1fd/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 24 Comm: kworker/u4:1 Not tainted 5.11.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-8:0) ==================================================================