syzbot

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BUG: KCSAN: data-race in iput / move_expired_inodes

read-write to 0xffff888009ac0cd8 of 8 bytes by task 3274 on cpu 0:
 move_expired_inodes+0x1bf/0x490 fs/fs-writeback.c:1257
 queue_io+0xe1/0x2b0 fs/fs-writeback.c:1304
 wb_writeback+0x255/0x660 fs/fs-writeback.c:1892
 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

read to 0xffff888009ac0cd8 of 8 bytes by task 8457 on cpu 1:
 iput+0x2e/0x510 fs/inode.c:1669
 dentry_unlink_inode+0x1f3/0x210 fs/dcache.c:374
 d_delete+0x70/0xa0 fs/dcache.c:2477
 vfs_rmdir+0x271/0x290 fs/namei.c:3729
 do_rmdir+0x16e/0x300 fs/namei.c:3776
 __do_sys_rmdir fs/namei.c:3794 [inline]
 __se_sys_rmdir fs/namei.c:3792 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:3792
 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: 8457 Comm: syz-executor.3 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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