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

write to 0xffff88812e14d180 of 4 bytes by task 4871 on cpu 1:
 d_set_d_op+0x17f/0x220 fs/dcache.c:1882
 simple_lookup+0x78/0x90 fs/libfs.c:73
 lookup_open fs/namei.c:3085 [inline]
 open_last_lookups fs/namei.c:3180 [inline]
 path_openat+0xa72/0x20a0 fs/namei.c:3368
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812e14d180 of 4 bytes by task 21475 on cpu 0:
 d_in_lookup include/linux/dcache.h:363 [inline]
 d_wait_lookup fs/dcache.c:2528 [inline]
 d_alloc_parallel+0x625/0xd10 fs/dcache.c:2616
 lookup_open fs/namei.c:3033 [inline]
 open_last_lookups fs/namei.c:3180 [inline]
 path_openat+0x650/0x20a0 fs/namei.c:3368
 do_filp_open+0xbd/0x1d0 fs/namei.c:3398
 do_sys_openat2+0xa3/0x250 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 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: 21475 Comm: systemd-udevd Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================