KCSAN: data-race in d_lru

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in d_lru_del / dput (2) fs				1	1423d	1423d	0/26	closed as invalid on 2020/06/18 14:13
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BUG: KCSAN: data-race in d_lru_del / dput

write to 0xffff888124032480 of 4 bytes by task 8130 on cpu 0:
 d_lru_del+0x5d/0xf0 fs/dcache.c:410
 select_collect+0x179/0x1a0 fs/dcache.c:1484
 d_walk+0x1b1/0x520 fs/dcache.c:1305
 shrink_dcache_parent+0xa4/0x280 fs/dcache.c:1544
 d_invalidate fs/dcache.c:1656 [inline]
 d_invalidate+0x85/0x180 fs/dcache.c:1641
 proc_flush_task_mnt fs/proc/base.c:3147 [inline]
 proc_flush_task+0x14c/0x2e0 fs/proc/base.c:3217
 release_task+0x83/0xc60 kernel/exit.c:202
 wait_task_zombie kernel/exit.c:1106 [inline]
 wait_consider_task+0x190e/0x1a10 kernel/exit.c:1333
 do_wait_thread kernel/exit.c:1396 [inline]
 do_wait+0x1c9/0x4c0 kernel/exit.c:1467
 kernel_wait4+0x156/0x240 kernel/exit.c:1639
 __do_sys_wait4+0xea/0x100 kernel/exit.c:1651
 __se_sys_wait4 kernel/exit.c:1647 [inline]
 __x64_sys_wait4+0x5e/0x80 kernel/exit.c:1647
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888124032480 of 4 bytes by task 8140 on cpu 1:
 fast_dput fs/dcache.c:727 [inline]
 dput+0x4d/0x750 fs/dcache.c:846
 __fput+0x2ac/0x520 fs/file_table.c:293
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8140 Comm: ps Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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