==================================================================
BUG: KCSAN: data-race in __dentry_kill / d_alloc_parallel

read to 0xffff8880b798d300 of 4 bytes by task 17942 on cpu 1:
 dentry_unlist fs/dcache.c:544 [inline]
 __dentry_kill+0x1be/0x3c0 fs/dcache.c:575
 dentry_kill fs/dcache.c:698 [inline]
 dput+0x3b5/0x750 fs/dcache.c:859
 path_put fs/namei.c:482 [inline]
 terminate_walk+0x107/0x250 fs/namei.c:596
 path_lookupat.isra.0+0x27e/0x5a0 fs/namei.c:2322
 filename_lookup+0x145/0x2b0 fs/namei.c:2338
 user_path_at_empty+0x4c/0x70 fs/namei.c:2598
 do_readlinkat+0x84/0x220 fs/stat.c:399
 __do_sys_readlink fs/stat.c:432 [inline]
 __se_sys_readlink fs/stat.c:429 [inline]
 __x64_sys_readlink+0x51/0x70 fs/stat.c:429
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b798d300 of 4 bytes by task 17982 on cpu 0:
 d_alloc_parallel+0x54d/0xea0 fs/dcache.c:2610
 __lookup_slow+0xb4/0x2a0 fs/namei.c:1646
 lookup_slow+0x4f/0x70 fs/namei.c:1680
 walk_component+0x4a2/0xe80 fs/namei.c:1800
 link_path_walk.part.0+0x5d3/0xa90 fs/namei.c:2131
 link_path_walk fs/namei.c:2259 [inline]
 path_lookupat.isra.0+0x77/0x5a0 fs/namei.c:2307
 filename_lookup+0x145/0x2b0 fs/namei.c:2338
 user_path_at_empty+0x4c/0x70 fs/namei.c:2598
 do_readlinkat+0x84/0x220 fs/stat.c:399
 __do_sys_readlink fs/stat.c:432 [inline]
 __se_sys_readlink fs/stat.c:429 [inline]
 __x64_sys_readlink+0x51/0x70 fs/stat.c:429
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17982 Comm: udevd Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================