syzbot

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BUG: KCSAN: data-race in __fsnotify_parent / vfs_unlink

write to 0xffff88812eed7c00 of 4 bytes by task 18680 on cpu 1:
 dont_mount include/linux/dcache.h:358 [inline]
 vfs_unlink+0x289/0x400 fs/namei.c:4027
 do_unlinkat+0x238/0x4f0 fs/namei.c:4092
 __do_sys_unlink fs/namei.c:4139 [inline]
 __se_sys_unlink fs/namei.c:4137 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4137
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812eed7c00 of 4 bytes by task 18667 on cpu 0:
 __fsnotify_parent+0x7d/0x430 fs/notify/fsnotify.c:187
 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+0x40c/0x770 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+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00400000 -> 0x00400100

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18667 Comm: syz-executor.5 Tainted: G        W         5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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