==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / writeback_sb_inodes

write to 0xffff888129ec31d0 of 8 bytes by task 25 on cpu 0:
 writeback_sb_inodes+0x427/0xff0 fs/fs-writeback.c:1190
 wb_writeback+0x28d/0x6f0 fs/fs-writeback.c:1894
 wb_do_writeback+0x101/0x5f0 fs/fs-writeback.c:2039
 wb_workfn+0xc8/0x470 fs/fs-writeback.c:2080
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888129ec31d0 of 8 bytes by task 9650 on cpu 1:
 __mark_inode_dirty+0xb9/0x7f0 fs/fs-writeback.c:2274
 mark_buffer_dirty+0x14b/0x260 fs/buffer.c:1141
 mark_buffer_dirty_inode+0x48/0x1b0 fs/buffer.c:575
 __ext4_handle_dirty_metadata+0x1af/0x5a0 fs/ext4/ext4_jbd2.c:360
 ext4_handle_dirty_dirblock+0x184/0x330 fs/ext4/namei.c:411
 ext4_delete_entry+0x23a/0x340 fs/ext4/namei.c:2535
 ext4_rmdir+0x5f5/0x930 fs/ext4/namei.c:3147
 vfs_rmdir+0x135/0x2a0 fs/namei.c:3712
 do_rmdir+0x16e/0x300 fs/namei.c:3773
 __do_sys_rmdir fs/namei.c:3791 [inline]
 __se_sys_rmdir fs/namei.c:3789 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:3789
 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: 9650 Comm: syz-executor.3 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================