syzbot

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BUG: KCSAN: data-race in __fsnotify_parent / d_set_mounted

write to 0xffff88810bf5ba80 of 4 bytes by task 21615 on cpu 1:
 d_set_mounted+0x112/0x190 fs/dcache.c:1459
 get_mountpoint+0x1ac/0x2f0 fs/namespace.c:740
 lock_mount+0x86/0x1d0 fs/namespace.c:2200
 do_move_mount+0x21/0x810 fs/namespace.c:2667
 do_move_mount_old fs/namespace.c:2751 [inline]
 path_mount+0xb1e/0x1c10 fs/namespace.c:3203
 do_mount fs/namespace.c:3218 [inline]
 __do_sys_mount fs/namespace.c:3426 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3403
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3403
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810bf5ba80 of 4 bytes by task 21608 on cpu 0:
 __fsnotify_parent+0x7d/0x430 fs/notify/fsnotify.c:180
 fsnotify_parent include/linux/fsnotify.h:68 [inline]
 fsnotify_file include/linux/fsnotify.h:90 [inline]
 fsnotify_modify include/linux/fsnotify.h:255 [inline]
 vfs_write+0x430/0x7c0 fs/read_write.c:609
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 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: 0 PID: 21608 Comm: syz-executor.3 Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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